FN Thomson Reuters Web of Science™ VR 1.0 PT S AU ReVelle, DO Whitaker, RW Armstrong, WT AF ReVelle, DO Whitaker, RW Armstrong, WT BE Johnson, CB Maclay, TD Allahdadi, FA TI Infrasound from the El Paso super-bolide of October 9, 1997 SO IMAGE INTENSIFIERS AND APPLICATIONS; AND CHARACTERISTICS AND CONSEQUENCES OF SPACE DEBRIS AND NEAR-EARTH OBJECTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Image Intensifiers and Applications; and Characteristics and Consequences of Space Debris and Near-Earth Objects CY JUL 23, 1998 CL SAN DIEGO, CA SP SPIE Int Soc Opt Engn DE infrasound; meteor acoustics; blast waves; super-bolides; long-range sound propagation AB During the noon hour on October 9, 1997 an extremely bright fireball (similar to -21.5 in stellar magnitude putting it into the class of a super-bolide) was observed over western Texas with visual sightings from as far away as Arizona to northern Mexico and even in northern New Mexico over 300 miles away. This event produced tremendously loud sonic boom reports in the El Paso area. It was also detected locally by 4 seismometers which are part of a network of 5 seismic stations operated by the University of Texas at EI Paso (UTEP). Subsequent investigations of the data from the six infrasound arrays used by LANL (Los Alamos National Laboratory) and operated for the DOE (Department of Energy) as a part of the CTB (Comprehensive Test Ban) Research and Development program for the IMS (International Monitoring System) showed the presence of an infrasonic signal from the proper direction at the correct time for this super-bolide from two of our six arrays. Both the seismic and infrasound recordings indicated that an explosion occurred in the atmosphere at source heights from 28-30 km, having its epicenter slightly to the northeast of Horizon City, Texas. The signal characteristics, analyzed from similar to 0.1 to 5.0 Hz, include a total duration of similar to 4 min (at Los Alamos, LA) to > similar to 5 min at Lajitas, Texas, TXAR, another CTB IMS array operated by E. Herrin at Southern Methodist University (SMU) for a source directed from LA toward 171-180 deg and fi-om TXAR of similar to 321-4 deg respectively fr om true north. The observed signal trace velocities (for the part of the recording with the highest cross-correlation) at LA ranged from 300-360 m/sec with a signal velocity of 0.30 +/- 0.03 km/sec, implying a Stratospheric (S Type) ducted path. The dominant signal frequency at LA was from 0.20 to 0.80 Hz, with a peak near 0.3 Hz. These highly correlated signals at LA had a very large, peak to peak, maximum amplitude of 21.0 microbars (2.1 Pa). Our analysis, using several methods that incorporate various observed signal characteristics, total distance traveled, etc., indicates that the super-bolide probably had a source energy in the range between 10-100 tons (TNT equivalent). This is somewhat smaller than the source energy estimate made using US DoD satellite data (USAF news release, June 8, 1998). C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP ReVelle, DO (reprint author), Univ Calif Los Alamos Natl Lab, MS F659, Los Alamos, NM 87545 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2889-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3434 BP 66 EP 77 DI 10.1117/12.331223 PG 12 WC Engineering, Aerospace; Optics; Imaging Science & Photographic Technology SC Engineering; Optics; Imaging Science & Photographic Technology GA BM32N UT WOS:000078391600008 ER PT S AU Sweatt, WC Boye, CA Gentry, SM Descour, MR Stallard, BR Grotbeck, CL AF Sweatt, WC Boye, CA Gentry, SM Descour, MR Stallard, BR Grotbeck, CL BE Descour, MR Shen, SS TI ISIS; An information-efficient spectral imaging system SO IMAGING SPECTROMETRY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Imaging Spectrometry IV CY JUL 20-21, 1998 CL SAN DIEGO, CA SP SPIE Int Soc Opt Engn AB A specialized hyperspectral imager has been developed that preprocesses the spectra from an image before the light reaches the detectors. This "optical computer" does not allow the flexibility of digital post-processing. However, the processing is done in real time and the system can examine approximate to 2 x 10(6) scene pixels/sec. Therefore, outdoors it could search for pollutants, vegetation types, minerals, or man-made objects. On a high-speed production line it could identify defects in sheet products like plastic wrap or film, or on painted or plastic parts. ISIS is a line scan imager. A spectrally dispersed slit image is projected on a Spatial Light Modulator. The SLM is programmed to take the inner product of the spectral intensity vector and a spectral basis vector. The SLM directs the positive and negative parts of the inner product to different linear detector arrays so the signal difference equals the inner product. We envision a system with one telescope and approximate to 4 SLMs. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sweatt, WC (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 10 Z9 10 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2893-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3438 BP 98 EP 106 DI 10.1117/12.328092 PG 9 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BL91T UT WOS:000077137900010 ER PT S AU Stallard, BR Gentry, SM AF Stallard, BR Gentry, SM BE Descour, MR Shen, SS TI Construction of filter vectors for the information-efficient spectral imaging sensor SO IMAGING SPECTROMETRY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Imaging Spectrometry IV CY JUL 20-21, 1998 CL SAN DIEGO, CA SP SPIE Int Soc Opt Engn DE imaging spectrometry; linear discriminant analysis; optical data compression AB The information-efficient spectral imaging sensor (ISIS) seeks to improve system performance by processing hyperspectral information in the optical hardware. Its output may be a gray scale image in which one attempts to maximize the contrast between a given target and the background. Alternatively, its output may be a small number of images, rather than a full data cube, that retain the essential information required in the application. The principal advantage of ISIS is that it offers the discrimination of hyperspectral imaging while achieving the signal-to-noise ratio of multispectral imaging. The paper focuses on construction of the filter vectors that are needed to program ISIS. The instrument produces an image which is essentially a dot product of the scene and the filter vector. Both single vector and multiple vector approaches are considered. Also, we discuss some subtle points related to optimizing the filter vectors. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Stallard, BR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2893-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3438 BP 172 EP 182 DI 10.1117/12.328100 PG 11 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BL91T UT WOS:000077137900018 ER PT S AU Borel, CC Clodius, WB Villeneuve, PV AF Borel, CC Clodius, WB Villeneuve, PV BE Descour, MR Shen, SS TI Synthetic hyperspectral data cubes for complex thermal scenes SO IMAGING SPECTROMETRY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Imaging Spectrometry IV CY JUL 20-21, 1998 CL SAN DIEGO, CA SP SPIE Int Soc Opt Engn DE hyperspectral; scene simulation; gas plume detection; temperature and emissivity separation AB Generating synthetic hyperspectral data cubes for the thermal is useful because it is very expensive to design and fly such sensors. Using synthetic data is useful in performing trade-off studies, e.g. spectral and radiometric performance requirements, and also in testing new algorithms, e.g. temperature emissivity separation. We have developed a method to simulate complex thermal scenes under variable solar illumination, different materials and including gas plumes. The IDL-based scene simulation tool consists of public domain tools for: 3-D geometry generation, raytracing, spectral and thermal property libraries, atmospheric transmission and emission modeling. The data can then be used in standard hyperspectral processing programs or processed by special purpose programs. We show how this model can be used to generate synthetic data cubes for dispersive and Fourier transform infrared spectrometers (FTIR). The data in turn is then used to evaluate algorithms to separate temperature and emissivity. C1 Univ Calif Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, Nonproliferat & Int Secur Div, Los Alamos, NM 87545 USA. RP Borel, CC (reprint author), Univ Calif Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, Nonproliferat & Int Secur Div, NIS-2,MS C323, Los Alamos, NM 87545 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2893-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3438 BP 222 EP 231 DI 10.1117/12.328106 PG 10 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BL91T UT WOS:000077137900023 ER PT S AU Weber, PG Bender, SC Borel, CC Clodius, WB Garrett, A Kay, RR Pendergast, MM Smith, BW AF Weber, PG Bender, SC Borel, CC Clodius, WB Garrett, A Kay, RR Pendergast, MM Smith, BW BE Descour, MR Shen, SS TI Multispectral thermal imaging SO IMAGING SPECTROMETRY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Imaging Spectrometry IV CY JUL 20-21, 1998 CL SAN DIEGO, CA SP SPIE Int Soc Opt Engn AB Many remote sensing applications rely on imaging spectrometry. Here we use imaging spectrometry for thermal and multispectral signatures measured from a satellite platform enhanced with a combination of accurate calibrations and on-board data for correcting atmospheric distortions. Our approach is supported by physics-based end-to-end modeling and analysis, which permits a cost-effective balance between various hardware and software aspects. C1 Univ Calif Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, Los Alamos, NM 87545 USA. RP Weber, PG (reprint author), Univ Calif Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, D436, Los Alamos, NM 87545 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2893-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3438 BP 234 EP 242 DI 10.1117/12.328118 PG 9 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BL91T UT WOS:000077137900024 ER PT S AU Moya, MM Taylor, JG Stallard, BR Motomatsu, SE AF Moya, MM Taylor, JG Stallard, BR Motomatsu, SE BE Descour, MR Shen, SS TI Anomaly detection using simulated MTI data cubes derived from HYDICE data SO IMAGING SPECTROMETRY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Imaging Spectrometry IV CY JUL 20-21, 1998 CL SAN DIEGO, CA SP SPIE Int Soc Opt Engn AB In this work, we quantify the separability between specific materials and the natural background by applying Receiver Operating Curve (ROC) analysis to the residual errors from a linear unmixing. We apply the ROC analysis to quantify performance of the Multi-spectral Thermal Imager (MTI). We describe the MTI imager and simulate its data by filtering HYDICE hyperspectral imagery both spatially and spectrally and by introducing atmospheric effects corresponding to the MTI satellite altitude. We compare and contrast the individual effects on performance of spectral resolution, spatial resolution, atmospheric corrections and varying atmospheric conditions. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Moya, MM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2893-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3438 BP 355 EP 366 DI 10.1117/12.328116 PG 12 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BL91T UT WOS:000077137900035 ER PT B AU Berge, PA Berryman, JG Blair, SC Pena, C AF Berge, PA Berryman, JG Blair, SC Pena, C BE Frost, JD McNeil, S TI Scalar properties of transversely isotropic tuff from images of orthogonal cross sections SO IMAGING TECHNOLOGIES: TECHNIQUES AND APPLICATIONS IN CIVIL ENGINEERING LA English DT Proceedings Paper CT 2nd International Conference on Imaging Technologies - Techniques and Applications in Civil Engineering CY MAY 25-30, 1997 CL DAVOS, SWITZERLAND SP Engn Fdn, Amer Soc Civil Engineers, Tech Council Comp Practices, Imaging Technol Comm ID 2-POINT CORRELATION-FUNCTIONS AB Image processing methods have been used very effectively to estimate physical properties of isotropic porous earth materials such as sandstones. Anisotropic materials can also be analyzed in order to estimate their physical properties, but additional care and a larger number of well-chosen images of cross sections are required to obtain correct results. Although low-symmetry anisotropic media present difficulties for two-dimensional image processing methods, geologic materials are often transversely isotropic. Scalar properties of porous materials such as porosity and specific surface area can be determined with only minor changes in the analysis when the medium is transversely isotropic rather than isotropic. For example, in a rock that is transversely isotropic due to thin layers or beds, the overall porosity may be obtained by analyzing images of cross sections taken orthogonal to the bedding planes, whereas cross sections lying within the bedding planes will determine only the local porosity of the bed itself. It is known for translationally invariant anisotropic media that the overall specific surface area can be obtained from radial averages of the two-point correlation function in the full three-dimensional volume. Layered materials are not translationally invariant in the direction of the layering, but we show nevertheless how averages of cross sections may be used to obtain the specific surface area for a transversely isotropic rock. We report values of specific surface area obtained for thin sections of Topopah Spring Tuff from Yucca Mountain, Nevada. This formation is being evaluated as a potential host rock for geologic disposal of nuclear waste. Although the present work has made use of thin sections of tuff for the images, the same methods of analysis could also be used to simplify quantitative analysis of three-dimensional volumes of pore structure data obtained by means of x-ray microtomography or other methods, using only a few representative cross sections chosen from the full three-dimensional data set. This approach provides a quick and easy way to get initial estimates of physical properties that can later be refined using more time-consuming and computationally intensive methods. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Berge, PA (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 USA BN 0-7844-0325-2 PY 1998 BP 185 EP 196 PG 12 WC Engineering, Civil SC Engineering GA BM48R UT WOS:000078888400019 ER PT B AU Ginsparg, P AF Ginsparg, P BE Butterworth, I TI Electronic research archives for physics SO IMPACT OF ELECTRONIC PUBLISHING ON THE ACADEMIC COMMUNITY SE WENNER-GREN INTERNATIONAL SERIES LA English DT Proceedings Paper CT Workshop on the Impact of Electronic Publishing on the Academic Community CY APR 17-20, 1997 CL WENNER GREN CTR, STOCKHOLM, SWEDEN SP Acad Europaea HO WENNER GREN CTR AB I describe a set of automated archives for electronic communication of research information thar has been operational in many fields of physics, and some related and unrelated disciplines, starting from 1991. These archives now serve over 50000 users worldwide from over 100 countries, and process many millions of electronic transactions per month. In some fields of physics, they have already supplanted traditional research journals as conveyers of both topical and archival research information. Many of the lessons learned from these systems should carry over to other fields of scholarly publication, i.e. those wherein authors are writing not for direct financial remuneration in the form of royalties, but rather primarily to communicate information (for the advancement of knowledge, with attendant benefits to their careers and professional reputations). These archives have in addition proven equally indispensible to researchers in less developed countries. C1 Univ Calif Los Alamos Natl Lab, Div Theory, Los Alamos, NM 87545 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU PORTLAND PRESS LTD PI LONDON PA 59 PORTLAND PL, LONDON W1N 3AJ, ENGLAND BN 1-85578-122-0 J9 WENN GR INT PY 1998 VL 73 BP 32 EP 43 PG 2 WC Communication; Information Science & Library Science SC Communication; Information Science & Library Science GA BL02K UT WOS:000074071800007 ER PT S AU Peterson, EJ Arendt, PN Coulter, JY Dowden, PC Foltyn, SR Groves, JR Hults, WL Smith, JL Willis, JO AF Peterson, EJ Arendt, PN Coulter, JY Dowden, PC Foltyn, SR Groves, JR Hults, WL Smith, JL Willis, JO BE WongNg, W Balachandran, U Bhalla, AS TI XRD analysis of YBCO superconducting films SO IMPACT OF RECENT ADVANCES IN PROCESSING OF CERAMIC SUPERCONDUCTORS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT Symposium on Impact of Recent Advances in Processing of Ceramic Superconductors, at the 99th Annual Meeting of the American-Ceramic-Society CY MAY 05-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc AB X-ray diffraction (XRD) analysis was performed on samples of YBa2Cu3O7-delta (YBCO) thin films that had been deposited by pulsed laser deposition at fast and slow rates on SrTiO3 single crystal substrates. As deposited samples were given subsequent high temperature post anneal treatments. While oxygen stoichiometry most likely remained essentially constant at fully oxygenated values in these samples, c-axis lattice parameter and nonuniform strain values obtained from the XRD analysis were found to closely track critical current density values. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Peterson, EJ (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 1 Z9 1 U1 1 U2 5 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-031-9 J9 CERAM TRANS PY 1998 VL 84 BP 83 EP 91 PG 9 WC Materials Science, Ceramics; Materials Science, Coatings & Films SC Materials Science GA BL05V UT WOS:000074134800008 ER PT S AU Balachandran, U AF Balachandran, U BE WongNg, W Balachandran, U Bhalla, AS TI Development of ceramic superconductors for electric power applications SO IMPACT OF RECENT ADVANCES IN PROCESSING OF CERAMIC SUPERCONDUCTORS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT Symposium on Impact of Recent Advances in Processing of Ceramic Superconductors, at the 99th Annual Meeting of the American-Ceramic-Society CY MAY 05-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc AB The U.S. Department of Energy supports an applied superconductivity program entitled "Superconductivity Program for Electric Power Systems." Activities under this program are designed to help develop the high-temperature superconductor (HTS) technology that is needed for industry to proceed with the commercial development of electric power applications. Research is conducted in three categories: wire development, systems technology development, and Superconductivity Partnership Initiative (SPI). Wire development activities are devoted to improving the critical current density (J(c)) of short-length HTS wire, whereas activities in systems technology development focus on fabrication of long-length wires, coils, and magnets. Finally, SPI activities focus on the development of prototypes that consist of a generator coil, a fault current limiter, a transmission cable, and a motor. A current overview and recent progress in the development of HTSs are outlined in this paper. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Balachandran, U (reprint author), Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-031-9 J9 CERAM TRANS PY 1998 VL 84 BP 157 EP 171 PG 15 WC Materials Science, Ceramics; Materials Science, Coatings & Films SC Materials Science GA BL05V UT WOS:000074134800014 ER PT S AU Holesinger, TG Hults, WL Dai, WM AF Holesinger, TG Hults, WL Dai, WM BE WongNg, W Balachandran, U Bhalla, AS TI Isothermal melt processing of BI-2212 wires and tapes SO IMPACT OF RECENT ADVANCES IN PROCESSING OF CERAMIC SUPERCONDUCTORS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT Symposium on Impact of Recent Advances in Processing of Ceramic Superconductors, at the 99th Annual Meeting of the American-Ceramic-Society CY MAY 05-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc AB Isothermal melt processing has been used to produce high critical currents (I-c's) and current densities (J(c)'s) in Bi2Sr2CaCu2Oy round wires and flat tapes, I-c's and J(c)'s of 225 A and 80 kA/cm(2) have been obtained in short length, monocore wires. However, voids and other macroscopic defects have limited performance over longer lengths. Isothermally melt processed tapes have yielded I-c and J(c) values up to 341 A and 245 kA/cm(2) although performance over longer lengths is somewhat reduced. A test coil made from 0.5 m of tape yielded I-c and J(c) values of 208 A and 153 kA/cm(2), respectively. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Holesinger, TG (reprint author), Univ Calif Los Alamos Natl Lab, MS G755, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-031-9 J9 CERAM TRANS PY 1998 VL 84 BP 175 EP 184 PG 10 WC Materials Science, Ceramics; Materials Science, Coatings & Films SC Materials Science GA BL05V UT WOS:000074134800015 ER PT S AU Dorris, SE Ashcom, N Truchan, T Vasanthamohan, N Burlone, DA Woolf, LD AF Dorris, SE Ashcom, N Truchan, T Vasanthamohan, N Burlone, DA Woolf, LD BE WongNg, W Balachandran, U Bhalla, AS TI Coated-wire-in-tube processing of bismuth-2223 superconductors SO IMPACT OF RECENT ADVANCES IN PROCESSING OF CERAMIC SUPERCONDUCTORS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT Symposium on Impact of Recent Advances in Processing of Ceramic Superconductors, at the 99th Annual Meeting of the American-Ceramic-Society CY MAY 05-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc AB A coated-wire-in-tube (CWIT) process greatly increases the silver/superconductor interface area in silver-sheathed Bi-2223 superconductors. When the performance of CWIT samples is compared to that of conventional monofilaments made with the same powder, critical current density increases significantly with increased silver/superconductor interface area. Benefits of increasing the silver/superconductor interface area are realized only when there is good continuity of the coated wires, which can be preserved by proper mechanical processing. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Dorris, SE (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-031-9 J9 CERAM TRANS PY 1998 VL 84 BP 185 EP 193 PG 9 WC Materials Science, Ceramics; Materials Science, Coatings & Films SC Materials Science GA BL05V UT WOS:000074134800016 ER PT S AU Vasanthamohan, N Singh, JP Khanna, G Lanagan, MT AF Vasanthamohan, N Singh, JP Khanna, G Lanagan, MT BE WongNg, W Balachandran, U Bhalla, AS TI Stress/strain performance of sheathed bismuth-2223 superconductors SO IMPACT OF RECENT ADVANCES IN PROCESSING OF CERAMIC SUPERCONDUCTORS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT Symposium on Impact of Recent Advances in Processing of Ceramic Superconductors, at the 99th Annual Meeting of the American-Ceramic-Society CY MAY 05-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc AB Besides possessing high current transport properties, superconductors employed in several applications must also be capable of retaining those properties when subjected to stresses and strains. This paper explores the potential for Consil, an alloy containing Ag, 0.25 wt.% Ni and 0.25 wt.% Mg, to serve as a potential sheathing material in the processing of BSCCO (2223) superconductors. Strain tolerance measurements at 77 K and 0 Tesla indicate superior performance by Consil-sheathed tapes over tapes sheathed in commercially pure Ag. While the pure Ag undergoes an abrupt decrease in critical current (I-c) beyond a certain strain level (0.2% strain), Consil-sheathed tapes show a more gradual decrease. However, despite their superior performance under strain, the Consil-sheathed tapes did not yield critical current density (J(c)) values that are normally obtained in Ag-sheathed tapes. The reason for this behavior has been attributed to poor phase conversion of the superconducting core inside the Consil sheath, even after extended sintering times (250 h). C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Vasanthamohan, N (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-031-9 J9 CERAM TRANS PY 1998 VL 84 BP 195 EP 206 PG 12 WC Materials Science, Ceramics; Materials Science, Coatings & Films SC Materials Science GA BL05V UT WOS:000074134800017 ER PT J AU Whittaker, JW Brosey, WD Hamstad, MA AF Whittaker, JW Brosey, WD Hamstad, MA TI Assessment of impact damage in Kevlar (R)-epoxy, filament-wound, spherical test specimens by acoustic emission techniques SO IMPACT RESPONSE AND DYNAMIC FAILURE OF COMPOSITES AND LAMINATE MATERIALS, PTS 1 AND 2 SE KEY ENGINEERING MATERIALS LA English DT Article DE acoustic emission; AE; biaxial test specimens; composite materials; impact damage; residual strength; static load; thermo-acoustic emission ID COMPOSITE; STRENGTH; LOAD AB The results of a study of the acoustic emission (AE) behavior of impact-damaged, spherical, composite test specimens subjected to thermal cycling and biaxial mechanical loading are presented. Seven Kevlar(R)-epoxy, filament-wound, spherical composite test specimens were subjected to different levels of impact damage. The seven specimens were a subset of a group of 77 specimens made with simulated fabrication-induced flaws. The specimens were subjected to two or three cycles of elevated temperature and then hydraulically pressurized to failure, The pressurization regime consisted of two cycles to different intermediate levels with a hold at each peak pressure level; a final pressurization to failure followed, The thermal and pressurization cycles were carefully designed to stimulate AE production under defined conditions. Both impacted and nonimpacted specimens produced thermo-AE (the term given to emission stimulated by thermal loading), but impacted specimens produced significantly more. Thermo-AE was produced primarily by damaged composite material. Damaged material produced emission as a function of both rising and falling temperature, but the effect was not repeatable. More seriously damaged specimens produced very large quantities of emission. Use of multiple AE sensors enabled monitoring of different portions of the specimens during pressure loading. Emission sources were active at all monitored locations, but material damaged by impact produced significantly more emission. Specimen strength and AE Felicity Ratio (FR) decreased approximately linearly with impact damage level. Several alternative methods for determining FRs were examined; one method based on event rate provided the best correlations with specimen strength. Emission recorded during the static portion of the hydraulic loading cycles varied with load, time, and degree of damage. Static load AE behavior was quantified using a newly developed concept, the event-rate moment, and various correlations with residual strength were attempted. Correlations between residual strength, long-duration events, and even-rate moments were developed with varying degrees of success. C1 Lockheed Martin Energy Syst Inc, Oak Ridge Plant Y12, Oak Ridge, TN 37831 USA. Univ Denver, Dept Engn, Denver, CO 80208 USA. RP Whittaker, JW (reprint author), Lockheed Martin Energy Syst Inc, Oak Ridge Plant Y12, Oak Ridge, TN 37831 USA. NR 17 TC 1 Z9 1 U1 0 U2 0 PU TRANSTEC PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 1013-9826 J9 KEY ENG MAT PY 1998 VL 141-1 BP 65 EP 89 PN 1-2 PG 25 WC Materials Science, Multidisciplinary SC Materials Science GA BK32J UT WOS:000071781000005 ER PT S AU Mohandas, N Gimm, JA AF Mohandas, N Gimm, JA BE Mouritsen, OG Andersen, OS TI Molecular basis for red cell membrane properties SO IN SEARCH OF A NEW BIOMEMBRANE MODEL SE BIOLOGISKE SKRIFTER LA English DT Proceedings Paper CT International Symposium on in Search of a New Biomembrane Model CY AUG 13-16, 1997 CL ROYAL DANISH ACAD SCI & LETTERS, COPENHAGEN, DENMARK HO ROYAL DANISH ACAD SCI & LETTERS AB Encouraging recent developments have begun to bridge the gap between what we know about membrane biochemistry and our knowledge of in situ physical properties of the red cell membrane, a prototypical biological membrane. This review provides a contemporary view of the relationship between red cell membrane molecular architecture and membrane material properties, emphasizing new developments that underscore the subtleties of soft cell interfaces. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Mohandas, N (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ROYAL DANISH ACADEMY SCIENCES & LETTERS PI COPENHAGEN V PA H C ANDERSENS BLVD 35, DK-1553 COPENHAGEN V, DENMARK SN 0366-3612 BN 87-7304-292-7 J9 BIOL SKRIF PY 1998 VL 49 BP 143 EP 146 PG 4 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA BL92T UT WOS:000077171900023 ER PT J AU Gajraj, A Joubert, W Jones, J AF Gajraj, A Joubert, W Jones, J TI A parallel implementation of kriging with a trend SO IN SITU LA English DT Article AB This paper describes the parallelization of the GSLIB(I) ktb3dm code. The code is parallelized using the message passing paradigm, Parallel Virtual Machine (PVM), under a Multiple Instructions, Multiple Data (MIMD) architecture. The code performance is analyzed using different grid sizes of 5x5x1, 50x50x1, 100x100x1 and 500x500x1 with 1,2, 4, 8 and in some cases 16 processors on the Gray T3D supercomputer. The parallelization effort focused on the main kriging do loop. The results confirm that there is a substantial benefit to be derived in terms of CPU time savings (or execution speed) by using the parallel version of the code, especially when considering larger grids. Additionally, speed-up and scalability analyses show that actual speed-up is close to theoretical, while the code scales appropriately within the 1 to 16 processor range tested. The kriging of a quarter-million grid cell system fell from over 9 CPU minutes on one Gray T3D processor to about 1.25 CPU minutes on 16 processors on the same machine. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Amoco Corp, Houston, TX 77079 USA. RP Gajraj, A (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 10 TC 0 Z9 0 U1 0 U2 1 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0146-2520 J9 IN SITU JI In Situ PY 1998 VL 22 IS 2 BP 239 EP 261 PG 23 WC Energy & Fuels; Engineering, Chemical; Engineering, Petroleum; Engineering, Geological; Mining & Mineral Processing SC Energy & Fuels; Engineering; Mining & Mineral Processing GA ZV395 UT WOS:000074300300004 ER PT S AU Ressler, T Wong, J Metz, W AF Ressler, T Wong, J Metz, W BE Rosenthal, PA Duncan, WM Woollam, JA TI X-ray absorption spectroscopy as an in-situ tool in materials science SO IN SITU PROCESS DIAGNOSTICS AND INTELLIGENT MATERIALS PROCESSING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium In Situ Process Diagnostics and Intelligent Materials Processing CY DEC 02-05, 1997 CL BOSTON, MA SP Mat Res Soc (MRS) AB In addition to being an established technique for ex-situ structural studies, x-ray absorption spectroscopy (XAS) has recently been realized to be a powerful tool for in-situ time-resolved investigations in materials science. This paper describes two complementary techniques: quick-scanning EXAFS (QEXAFS) and energy-dispersive XAS (DXAS) which offer time resolution in the seconds and milliseconds range, respectively. Formation of a heterogeneous catalyst from a solid-state reaction of a precursor is presented as an example of a time-resolved XAS application. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Ressler, T (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 0 TC 1 Z9 1 U1 1 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-407-6 J9 MATER RES SOC SYMP P PY 1998 VL 502 BP 127 EP 132 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Ceramics; Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Engineering; Materials Science GA BL42U UT WOS:000075472800017 ER PT S AU Lauffer, JP Regelbrugge, ME Kwan, CM Lin, Y Xu, R Dohner, JL Hinnerichs, TD AF Lauffer, JP Regelbrugge, ME Kwan, CM Lin, Y Xu, R Dohner, JL Hinnerichs, TD BE Sater, JM TI Smart spindle unit for active chatter suppression of a milling machine Part II: dynamics and control SO INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES - SMART STRUCTURES AND MATERIALS 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Structures and Materials 1998 - Industrial and Commercial Applications of Smart Structures Technologies CY MAR 03-05, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Soc Exptl Mech Inc, Amer Soc Mech Engineers, BF Goodrich Aerosp, USAF Res Lab, Def Adv Res Projects Agcy, Ceram Soc Japan, Intelligent Mat Forum, Japan, USA Res Off DE milling tool chatter; chatter control; ceramic actuators; machine-tool dynamics AB This paper addresses dynamics and control issues encountered in development of a smart spindle unit (SSU) for suppressing chatter in milling operations. The SSU comprises a suite of strain, displacement and force sensors coupled to four, high-force, electrostrictive ceramic actuators through a digital control processor. The operating principles of the SSU are discussed, and salient dynamics of the SSU and generic milling tools are explored in this context. Dynamic characteristics measured using the SSU sensors are presented and discussed relative to their influence on chatter and control of chatter. C1 Sandia Natl Labs, Dept 1434 MS 0439, Albuquerque, NM 87185 USA. RP Lauffer, JP (reprint author), Sandia Natl Labs, Dept 1434 MS 0439, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2770-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3326 BP 167 EP 173 DI 10.1117/12.310631 PG 7 WC Engineering, Aerospace; Engineering, Mechanical; Optics; Transportation SC Engineering; Optics; Transportation GA BL31K UT WOS:000075067700016 ER PT J AU Sugama, T Sabatini, R Petrakis, L AF Sugama, T Sabatini, R Petrakis, L TI Decomposition of chrysotile asbestos by fluorosulfonic acid SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID FIBERS AB The effect of a fluorosulfonic acid (FSO3H) aqueous solution on decomposing the chrysotile asbestos fibers was investigated by using FT-IR, XRD, and XPS. From the equilibrium of FSO3H in an aqueous medium (FSO3H + H2O = HF + H2SO4), the resulting H2SO4 had a strong affinity for the external Mg(OH)(2) layers in the tubular, scroll-like chrysotile structure. This acid-base reaction led to the precipitation and lixiviation of MgSO4 . H2O, MgO, and Mg2+ ion. Once the breakage of the outer Mg(OH)(2) layers occurred, HF readily diffused into the inner silicious layers and then reacted with silicates, converting them into SiO2 hydrate and H2SiF6, while the ionic reaction between lixiviated Mg2+ and F- resulted in precipitating MgF2, thereby destroying the fibrous nature of the asbestos. An optimum combination of HF and H2SO4 contributed significantly to enhancing the rate of conversion of asbestos into nonfibrous materials in a short treatment time without any physical agitation. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RP Petrakis, L (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. EM petrakis@bnl.gov NR 28 TC 28 Z9 32 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD JAN PY 1998 VL 37 IS 1 BP 79 EP 88 DI 10.1021/ie9702744 PG 10 WC Engineering, Chemical SC Engineering GA YQ679 UT WOS:000071412400012 ER PT J AU Monazam, ER Shadle, LJ AF Monazam, ER Shadle, LJ TI Predictive tool to aid design and operations of pressurized fixed bed coal gasifiers SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article AB A mathematical model is presented to study the combustion and gasification of char with air and steam under pressure. A series of curves was obtained from the solutions of energy and mass balances for the probable range of operation in the gasification of char. Certain theoretical conclusions are drawn with respect to gasification of char in a fixed bed and found to be in accord with the results of the literature. A mathematical correlation is presented for conveniently calculating the product gas composition, the burning rate, the combustion zone thickness, the solids' maximum temperature, and the outlet gas temperature. This correlation is of general applicability, covers a wide range of operating conditions through use of multiple variance analysis, and may be used for pressures as high as 4200 kPa. Examples are given to illustrate the use and versatility of the correlation. C1 US DOE, Fed Energy Technol Ctr, Morgantown, WV 26507 USA. W Virginia Univ, Dept Mech & Aerosp Engn, Morgantown, WV 26505 USA. RP Shadle, LJ (reprint author), US DOE, Fed Energy Technol Ctr, POB 880, Morgantown, WV 26507 USA. OI Shadle, Lawrence/0000-0002-6283-3628 NR 21 TC 5 Z9 5 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD JAN PY 1998 VL 37 IS 1 BP 120 EP 130 DI 10.1021/ie970229w PG 11 WC Engineering, Chemical SC Engineering GA YQ679 UT WOS:000071412400016 ER PT J AU Ahluwalia, RK Geyer, HK Pereira, C Ackerman, JP AF Ahluwalia, RK Geyer, HK Pereira, C Ackerman, JP TI Modeling of a zeolite column for the removal of fission products from molten salt SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article AB During electrorefining of spent nuclear fuels, fission products, and actinides accumulate in the LiCl-KCl electrolyte salt. From the standpoint of high-level waste minimization, it is advantageous to remove these from the salt rather that discarding the salt after these have built up to certain concentrations. Laboratory experiments have shown that zeolite A has the desirable properties for selective removal of fission products by the ion-exchange process. An analytical model has been developed to assess the performance of the ion-exchange column and to scale up the data to engineering size equipment. The model employs empirically determined exchange factors to represent the equilibrium chemistry of the exchange process. The exchange kinetics is modeled by the Nernst-Planck equation applied to multicomponent diffusion in the zeolite pellet. The self-diffusion coefficients, derived from batch kinetic data, are substantially different for monovalent, divalent, and trivalent fission products. The method of characteristics is used to solve the transport equations for the salt phase. The computed breakthrough of the fission products through the experimental zeolite column is in partial hut not complete agreement with the measured concentration profiles. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Ahluwalia, RK (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 5 TC 10 Z9 10 U1 2 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD JAN PY 1998 VL 37 IS 1 BP 145 EP 153 DI 10.1021/ie970492x PG 9 WC Engineering, Chemical SC Engineering GA YQ679 UT WOS:000071412400018 ER PT S AU Ettinger, JM AF Ettinger, JM BE Aucsmith, D TI Steganalysis and game equilibria SO INFORMATION HIDING SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 2nd International Workshop on Information Hiding CY APR 14-17, 1998 CL PORTLAND, OREGON DE steganalysis; cryptanalysis; equilibria; shannon entropy; binary symmetric channel; active warden attack AB Steganography is the study of methods of concealing data in the noise of another data set. Steganalysis is the field of discovering hidden data and disrupting covert channels. We introduce a two-player, zero-sum, matrix game for the purpose of modeling the contest between a data-hider and a data-attacker. We then solve the game for equilibria, demonstrating that the form of the solution depends on whether the permitted distortion is less than or greater than d(c), the critical distortion. This critical point is a simple function of several parameters which define the game. We then solve two example cases to demonstrate the ideas presented in the general solution. The value of the game is the amount of information that may be reliably stored in the data set. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ettinger, JM (reprint author), Univ Calif Los Alamos Natl Lab, Mail Stop B-230, Los Alamos, NM 87545 USA. NR 8 TC 16 Z9 18 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-65386-4 J9 LECT NOTES COMPUT SC PY 1998 VL 1525 BP 319 EP 328 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BP55H UT WOS:000085483300022 ER PT S AU Biefeld, RM Allerman, AA Kurtz, SR Baucom, KC AF Biefeld, RM Allerman, AA Kurtz, SR Baucom, KC BE McDaniel, DL Manasreh, MO Miles, RH Sivananthan, S TI Recent progress in the growth of mid-IR emitters by metalorganic chemical vapor deposition SO INFRARED APPLICATIONS OF SEMICONDUCTORS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium F on Infrared Applications of Semiconductors II, at the 1997 MRS Fall Meeting CY DEC 01-04, 1997 CL BOSTON, MA SP Mat Res Soc, USAF Off Sci Res, USAF Res Lab, Semiconductor Laser Branch, USAF Res Lab, Space Sensing & Vehicle Control Branch AB We report on recent progress and improvements in the metal-organic chemical vapor deposition (MOCVD) growth of mid-infrared lasers and using a high speed rotating disk reactor (RDR). The devices contain AlAsSb claddings and strained InAsSb active regions. These lasers have multi-stage, type I InAsSb/InAsP quantum well active regions. A semi-metal GaAsSb/InAs layer acts as an internal electron source for the multi-stage injection lasers and AlAsSb is an electron confinement layer. These structures are the first MOCVD multi-stage devices. Growth in an RDR was necessary to avoid the previously observed Al memory effects found in conventional horizontal reactors. A single stage, optically pumped laser yielded improved power (> 650 mW/facet) at 80 K and 3.8 mu m. A multi-stage 3.8-3.9 mu m laser structure operated up to T=170 K. At 80 K, peak power > 100 mW and a high slope-efficiency were observed in gain guided lasers. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Biefeld, RM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-389-4 J9 MATER RES SOC SYMP P PY 1998 VL 484 BP 19 EP 29 PG 11 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Engineering; Materials Science GA BK98L UT WOS:000073983400004 ER PT S AU Olsen, CS Beeman, JW Hansen, WL Haller, EE AF Olsen, CS Beeman, JW Hansen, WL Haller, EE BE McDaniel, DL Manasreh, MO Miles, RH Sivananthan, S TI Germanium far infrared Blocked Impurity Band detectors SO INFRARED APPLICATIONS OF SEMICONDUCTORS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium F on Infrared Applications of Semiconductors II, at the 1997 MRS Fall Meeting CY DEC 01-04, 1997 CL BOSTON, MA SP Mat Res Soc, USAF Off Sci Res, USAF Res Lab, Semiconductor Laser Branch, USAF Res Lab, Space Sensing & Vehicle Control Branch AB We report on the development of Germanium Blocked Impurity Band (BIB) photoconductors for long wavelength infrared detection in the 100 to 250 mu m region. Liquid Phase Epitaxy (LPE) was used to grow the high purity blocking layer, and in some cases, the heavily doped infrared absorbing layer that comprise theses detectors. To achieve the stringent demands on purity and crystalline perfection we have developed a high purity LPE process which can be used for the growth of high purity as well as purely doped Ge epilayers. The low melting point, high purity metal, Pb, was used as a solvent. Pb has a negligible solubility <10(17) cm(-3) in Ge at 650 degrees C and is isoelectronic with Ge. We have identified the residual impurities Bi, P, and Sb in the Ge epilayers and have determined that the Pb solvent is the source. Experiments are in progress to purify the Pb. The first tests of BIB structures with the purely doped absorbing layer grown on high purity substrates look very promising. The detectors exhibit extended wavelength cutoff when compared to standard Ge:Ga photoconductors (155 mu m vs. 120 mu m) and show the expected asymmetric current-voltage dependencies. We are currently optimizing doping and layer thickness to achieve the optimum responsivity, Noise Equivalent Power (NEP), and dark current in our devices. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Olsen, CS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 4 Z9 4 U1 3 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-389-4 J9 MATER RES SOC SYMP P PY 1998 VL 484 BP 215 EP 220 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Engineering; Materials Science GA BK98L UT WOS:000073983400029 ER PT S AU Heffelfinger, JR Medlin, DL James, RB AF Heffelfinger, JR Medlin, DL James, RB BE McDaniel, DL Manasreh, MO Miles, RH Sivananthan, S TI Analysis of grain boundaries, twin boundaries and Te precipitates in Cd1-xZnxTe grown by high-pressure Bridgman method SO INFRARED APPLICATIONS OF SEMICONDUCTORS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium F on Infrared Applications of Semiconductors II, at the 1997 MRS Fall Meeting CY DEC 01-04, 1997 CL BOSTON, MA SP Mat Res Soc, USAF Off Sci Res, USAF Res Lab, Semiconductor Laser Branch, USAF Res Lab, Space Sensing & Vehicle Control Branch AB Grain boundaries and twin boundaries in commercial Cd1-xZnxTe, which is prepared by a high-pressure Bridgeman technique, have been investigated with transmission electron microscopy, scanning electron microscopy, infrared-light microscopy and visible-light microscopy. Boundaries inside these materials were found to be decorated with Te precipitates. The shape and local density of the precipitates were found to depend on the particular boundary. For precipitates that decorate grain boundaries, their microstructure was found to consist of a single, saucer-shaped grain of hexagonal Te (space group P3(1)21). Analysis of a Te precipate by selected-area diffraction revealed the Te to be aligned with the surrounding Cd1-xZnxTe grains. This alignment was found to match the (111) Cd1-xZnxTe planes with the (0111) planes of hexagonal Te. Crystallographic alignments between the Cd1-xZnxTe grains were also observed for a high-angle grain boundary. The structures of the grain boundaries and the Te/Cd1-xZnxTe interface are discussed. C1 Sandia Natl Labs, Ctr Mat Sci & Engn, Livermore, CA 94551 USA. RP Heffelfinger, JR (reprint author), Sandia Natl Labs, Ctr Mat Sci & Engn, POB 969, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-389-4 J9 MATER RES SOC SYMP P PY 1998 VL 484 BP 247 EP 252 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Engineering; Materials Science GA BK98L UT WOS:000073983400033 ER PT S AU Brunett, BA Van Scyoc, JM Yoon, H Gilbert, TS Schlesinger, TE Lund, JC James, RB AF Brunett, BA Van Scyoc, JM Yoon, H Gilbert, TS Schlesinger, TE Lund, JC James, RB BE McDaniel, DL Manasreh, MO Miles, RH Sivananthan, S TI Mapping of large area Cadmium Zinc Telluride (CZT) wafers: Apparatus and methods SO INFRARED APPLICATIONS OF SEMICONDUCTORS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium F on Infrared Applications of Semiconductors II, at the 1997 MRS Fall Meeting CY DEC 01-04, 1997 CL BOSTON, MA SP Mat Res Soc, USAF Off Sci Res, USAF Res Lab, Semiconductor Laser Branch, USAF Res Lab, Space Sensing & Vehicle Control Branch AB Cadmium Zinc Telluride (CZT) shows great promise as a semiconductor radiation detector material. CZT possesses advantageous material properties over other radiation detector materials in use today, such as a high intrinsic resistivity and a high cross-section for x and gamma-rays. However, presently available CZT is not without limitations. The hole transport properties severely limit the performance of these detectors, and the yield of material possessing adequate electron transport properties is currently much lower than desired. The result of these material deficiencies is a lack of inexpensive CZT crystals of large volume for several radiation detector applications. One approach to help alleviate this problem is to measure the spatial distribution (or map) the electrical properties of large area CZT wafers prior to device fabrication. This mapping can accomplish two goals: identify regions of the wafers suitable for detector fabrication and correlate the distribution of crystalline defects with the detector performance. The results of this characterization can then be used by the crystal manufacturers to optimize their growth processes. In this work, we discuss the design and performance of apparatus for measuring the electrical characteristics of entire CZT wafers (up to 10 cm x 10 cm). The data acquisition and manipulation will be discussed and some typical data will be presented. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Brunett, BA (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-389-4 J9 MATER RES SOC SYMP P PY 1998 VL 484 BP 253 EP 258 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Engineering; Materials Science GA BK98L UT WOS:000073983400034 ER PT S AU Kuzmenko, PJ Ciarlo, DR AF Kuzmenko, PJ Ciarlo, DR BE Fowler, AM TI Improving the optical performance of etched silicon gratings SO INFRARED ASTRONOMICAL INSTRUMENTATION, PTS 1-2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Infrared Astronomical Instrumentation CY MAR 23-25, 1998 CL KONA, HI SP Int Soc Opt Engn, European So Observ DE etched grating; immersion grating; grating scatter; grating resolution; echelle; silicon AB Silicon diffraction gratings fabricated by photolithography and anisotropic chemical etching offer unique advantages over conventional ruled gratings. Previous work (SPIE 2266, p. 566) showed a high amount of scatter from etched gratings and several waves of wavefront distortion due to an overetch problem. We recently began to study ways to improve the optical performance of etched silicon gratings. Defect etching was used to verify that our starting material was of high quality and that it could be polished to the required optical flatness without producing subsurface damage. We compared the effect of different etch mask materials (e.g. SiO2, Si3N4, Cr) and etching variables (etch temperature, concentration, additives, etc.) on the scatter and wavefront aberration of test gratings. Gratings masked with silicon nitride achieved sufficiently low wavefront distortion (0.07 wave RMS at 633 nm) to be useful in high resolution spectroscopy. The scatter was improved by a factor of two over the grating fabricated several years earlier, but is still a factor of 3 worse than a ruled echelle. A better lithography mask should reduce the scatter. The major issues in fabricating large etched gratings for astronomy are achieving good uniformity across the surface and the compatibility of thick silicon disks with standard semiconductor processing hardware. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Kuzmenko, PJ (reprint author), Sandia Natl Labs, M-S L-183,POB 808, Livermore, CA 94551 USA. NR 0 TC 24 Z9 24 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2801-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3354 BP 357 EP 367 DI 10.1117/12.317322 PN 1-2 PG 11 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BL60J UT WOS:000075982700041 ER PT S AU Datskos, PG Rajic, S Datskou, I Egert, CM AF Datskos, PG Rajic, S Datskou, I Egert, CM BE Dereniak, EL Sampson, RE TI Novel photon detection based on electronically-induced stress in silicon SO INFRARED DETECTORS AND FOCAL PLANE ARRAYS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Infrared Detectors and Focal Plane Arrays V CY APR 14-17, 1998 CL ORLANDO, FL SP SPIE DE microcantilever; photon detector; thermal detector; photo-induced stress; electron-hole pairs AB The feasibility of microcantilever-based optical detection is demonstrated. Specifically, we report here on an evaluation of laboratory prototypes that are based on commercially available microcantilevers. In this work, optical transduction techniques were used to measure microcantilever response to photons and study the electronic stress in silicon microcantilevers, and their temporal and photometric response. The photo-generation of free charge carriers (electrons, holes) in a semiconductor gives rise to photo-induced (electronic) mechanical strain. The excess charge carriers responsible for the photo-induced stress, were produced via photon irradiation from a diode laser with wavelength lambda = 780 nm. We found that for silicon, the photo-induced stress results in a contraction of the crystal lattice due to the presence of excess electron-hole-pairs. In addition, the photo-induced stress is of opposite direction and about four times larger than the stress resulting from direct thermal excitation. When charge carriers are generated in a short time, a very rapid deflection of the microcantilever is observed (response time similar to mu s). C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Datskos, PG (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 0 TC 5 Z9 6 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2828-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3379 BP 173 EP 181 DI 10.1117/12.317584 PG 9 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics; Imaging Science & Photographic Technology SC Engineering; Remote Sensing; Optics; Imaging Science & Photographic Technology GA BL57H UT WOS:000075913800017 ER PT S AU Clodius, WB Weber, PG Borel, CC Smith, BW AF Clodius, WB Weber, PG Borel, CC Smith, BW BE Holst, GC TI Multi-spectral band selection for satellite-based systems SO INFRARED IMAGING SYSTEMS: DESIGN, ANALYSIS, MODELING, AND TESTING IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Infrared Imaging System - Design, Analysis, Modeling, and Testing IX CY APR 15-16, 1998 CL ORLANDO, FL SP SPIE DE multispectral; design; analysis; modeling; satellite AB The design of satellite based multispectral imaging systems requires the consideration of a number of tradeoffs between cost and performance. The authors have recently been involved in the design and evaluation of a satellite based multispectral sensor operating from the visible through the long wavelength IR. The criteria that led to some of the proposed designs and the modeling used to evaluate and fine tune the designs will both be discussed. These criteria emphasized the use of bands for surface temperature retrieval and the correction of atmospheric effects. The impact of cost estimate changes on the final design will also be discussed. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Clodius, WB (reprint author), Univ Calif Los Alamos Natl Lab, MS C323, Los Alamos, NM 87545 USA. NR 0 TC 10 Z9 10 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2826-4 J9 P SOC PHOTO-OPT INS PY 1998 VL 3377 BP 11 EP 21 DI 10.1117/12.319369 PG 11 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL61D UT WOS:000076007800002 ER PT S AU Jefferson, KJ Wickstrom, RD AF Jefferson, KJ Wickstrom, RD BE Holst, GC TI Simulation of a fast framing staring sensor SO INFRARED IMAGING SYSTEMS: DESIGN, ANALYSIS, MODELING, AND TESTING IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Infrared Imaging System - Design, Analysis, Modeling, and Testing IX CY APR 15-16, 1998 CL ORLANDO, FL SP SPIE DE simulation; modeling; noise equivalent target; sensor performance; clutter; jitter; staring sensors AB A sensor system simulation has been developed which aids in the evaluation of a proposed fast framing staring sensor as it will perform in its operational environment. Beginning with a high resolution input image, a sequence of frames at the target sensor resolution are produced using the assumed platform motion and the contribution of various noise sources as input data. The resulting frame sequence can then be used to help define system requirements, to aid algorithm development, and to predict system performance. In order to assess the performance of a sensor system, the radiance measured by the system is modeled using a variety of scenarios. For performance prediction, the modeling effort is directed toward providing the ability to determine the minimum Noise Equivalent Target (NET) intensities for each band of the sensor system. The NET is calculated at the entrance pupil of the instrument in such a way that the results can be applied to a variety of point source targets and collection conditions. The intent is to facilitate further study within the user community as new mission areas and/or targets of interest develop that are not addressed explicitly during sensor conceptual design. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Jefferson, KJ (reprint author), Sandia Natl Labs, MS0980,POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2826-4 J9 P SOC PHOTO-OPT INS PY 1998 VL 3377 BP 22 EP 30 DI 10.1117/12.319378 PG 9 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL61D UT WOS:000076007800003 ER PT S AU Rienstra, JL AF Rienstra, JL BE Holst, GC TI Transformation of filter transmission data for f-number and chief ray angle SO INFRARED IMAGING SYSTEMS: DESIGN, ANALYSIS, MODELING, AND TESTING IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Infrared Imaging System - Design, Analysis, Modeling, and Testing IX CY APR 15-16, 1998 CL ORLANDO, FL SP SPIE DE interference filters; multispectral imaging; remote sensing AB This paper describes a method for transforming measured optical and infrared filter data for use with optical systems of arbitrary f-number and angle of incidence. Although it is generally desirable to have normal incidence at the filter (i.e., collimated light where an optical filter is used), other system design considerations may take precedence. In the case of a multispectral sensor under development at Sandia National Laboratories, system constraints require optical filter placement very near the focal plane. The light rays incident on the filters are therefore converging as determined by the system f-number while the chief ray of each ray bundle varies with focal plane position. To analyze the system's spectral response at different points on the focal plane, a method was devised to transform the filter vendor's measured data to account for the optical system design. The key to the transformation is the determination of weighting factors and shift factors for each angle of incidence making up a ray bundle. A computer worksheet was developed using a popular mathematical software package which performs this transformation for 75 key points on the focal plane. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Rienstra, JL (reprint author), Sandia Natl Labs, POB 5800,MS 0972, Albuquerque, NM 87185 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2826-4 J9 P SOC PHOTO-OPT INS PY 1998 VL 3377 BP 267 EP 275 DI 10.1117/12.319380 PG 9 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL61D UT WOS:000076007800029 ER PT B AU Gropp, W AF Gropp, W BE Veidenbaum, A Joe, K TI Which comes first: The architecture or the algorithm? SO INNOVATIVE ARCHITECTURE FOR FUTURE GENERATION HIGH-PERFORMANCE PROCESSORS AND SYSTEMS, PROCEEDINGS LA English DT Meeting Abstract CT International Workshop on Innovative Architecture for Future Generation High-Performance Processors and Systems CY OCT 22-24, 1997 CL MAUI, HI SP NSF, Maui High Performance Comp Ctr, Univ Illinois C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8424-0 PY 1998 BP 13 EP 13 DI 10.1109/IWIA.1997.670400 PG 1 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BK94K UT WOS:000073878600002 ER PT S AU Kiggans, JO Montgomery, FC Tiegs, TN Ferber, MK Lin, HT Davisson, CC Williams, AM AF Kiggans, JO Montgomery, FC Tiegs, TN Ferber, MK Lin, HT Davisson, CC Williams, AM BE Bansal, NP Logan, KV Singh, JP TI Microwave annealing of silicon nitride materials SO INNOVATIVE PROCESSING AND SYNTHESIS OF CERAMICS, GLASSES, AND COMPOSITES SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT International Symposium on Innovative Processing and Synthesis of Ceramics, Glasses and Composites, at the 99th Annual Meeting of the American-Ceramic-Society CY MAY 04-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc AB Dense silicon nitride-based ceramics were microwave annealed to determine if microwave heating offers advantages over conventional heating for the enhancement of the high temperature creep resistance. Gas pressure sintered silicon nitride (GPS-SN) and sintered reaction-bonded silicon nitride (SRBSN) were heated in microwave or graphite element furnaces at 1150 degrees C and 1600 degrees C. Annealed materials were characterized for the room and high temperature flexural strengths, room temperature fracture toughness values, and high temperature creep properties. In addition, SEM analyses were performed to study grain growth and other microstructural changes. The results of this study showed that both types of furnace anneals at 1150 degrees C lowered the room temperature strength and toughness values of both SRBSN and GPS-SN materials; however, the anneal treatments at 1600 degrees C had little effect on the room temperature properties. Both the SRBSN and GPS-SN control and annealed samples had reduced high temperature fast fracture strengths, when compared to the room temperature strengths. Creep tests at 1200 degrees C indicated that both the SRBSN and the GPS-SN materials that were annealed by microwave heating at 1150 degrees C for 20 h showed enhanced creep resistance, when compared to unheated controls and conventionally heated materials. No qualitative differences were seen in the microstructures of the SRBSN and the GPS-SN materials which could account for the differences in the creep properties of the annealed materials. Additional experimental work is in progress to further understand the mechanisms for the enhanced creep properties of silicon nitride materials annealed by microwave heating. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Kiggans, JO (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI kiggans, james/E-1588-2017 OI kiggans, james/0000-0001-5056-665X NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-030-0 J9 CERAM TRANS PY 1998 VL 85 BP 217 EP 227 PG 11 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BK58D UT WOS:000072614900017 ER PT S AU Jacobson, CP Visco, SJ De Jonghe, LC AF Jacobson, CP Visco, SJ De Jonghe, LC BE Bansal, NP Logan, KV Singh, JP TI Fabrication and properties on thin ceramic films deposited on porous substrates SO INNOVATIVE PROCESSING AND SYNTHESIS OF CERAMICS, GLASSES, AND COMPOSITES SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT International Symposium on Innovative Processing and Synthesis of Ceramics, Glasses and Composites, at the 99th Annual Meeting of the American-Ceramic-Society CY MAY 04-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc AB Bilayers consisting of highly porous substrates and dense thin-films of zirconia, ceria, and perovskite mixed conductors (SrZrO3, SrCeO3, and LaSrCoFeO3) have been successfully fabricated using colloidal deposition techniques. The films are well bonded to the substrate, gas tight and exhibit little interfacial resistance. Performance of solid oxide fuel cells (SOFCs) based on YSZ electrolytes of less than 10 mu m have achieved power densities close to 2 watts/cm(2) at 800 degrees C. Ceria based SOFCs exhibited excellent electrochemical performance over the temperature range of 600 to 800 degrees C with peak power in excess of 650 mW/cm(2) at 750 degrees C and close to 300 mW/cm(2) at 600 degrees C. In addition bilayers of thin SrCeO3 and La0.8Sr0.2Co0.8Fe0.2O3 (LSCF) suitable for gas separation or membrane reactors have been fabricated and fuel cells based on proton conducting SrZrO3 films have also been fabricated and tested. The approach is generic and allows deposition of a variety of thin ceramic films on porous substrates. The methodology is scaleable and inexpensive, and should allow substantial cost-savings in the manufacture and operation of electrochemical devices in the intermediate temperature range of 500-800 degrees C. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Jacobson, CP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-030-0 J9 CERAM TRANS PY 1998 VL 85 BP 323 EP 332 PG 10 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BK58D UT WOS:000072614900024 ER PT S AU Joo, F Kovacs, J Katho, A Benyei, AC Decuir, T Darensbourg, DJ AF Joo, F Kovacs, J Katho, A Benyei, AC Decuir, T Darensbourg, DJ BE Darensbourg, MY TI Ligands for water-solubilizing organometallic compounds SO INORGANIC SYNTHESES, VOL 32 SE Inorganic Syntheses LA English DT Article ID WATER-SOLUBLE PHOSPHINES; NUCLEOPHILIC-ADDITION; ORGANIC-CHEMISTRY; OLEFINS C1 Lajos Kossuth Univ, Inst Phys Chem, H-4010 Debrecen, Hungary. Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Lajos Kossuth Univ, Inst Phys Chem, H-4010 Debrecen, Hungary. RI Benyei, Attila/B-7368-2008; Agnes, Katho/H-4909-2011; Ferenc, Joo/B-3753-2011; Darensbourg, Donald/O-5084-2014 OI Darensbourg, Donald/0000-0001-9285-4895 NR 15 TC 94 Z9 94 U1 0 U2 3 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0073-8077 BN 0-471-24921-1 J9 INORG SYN PY 1998 VL 32 BP 1 EP 8 PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA BL16P UT WOS:000074527300001 ER PT B AU Smallwood, DO Cap, JS AF Smallwood, DO Cap, JS GP IES TI Salvaging pyrotechnic data with minor overloads and offsets SO INSTITUTE OF ENVIRONMENTAL SCIENCES AND TECHNOLOGY - 1998 PROCEEDINGS: DESIGN, TEST, AND EVALUATION PRODUCT RELIABILITY LA English DT Proceedings Paper CT 44th Annual Technical Meeting of the Institute-of-Environmental-Sciences-and-Technology on the 21st Century - A New Frontier in International Information Exchange CY APR 26-MAY 01, 1998 CL PHOENIX, AZ SP Inst Environm Sci & Technol DE pyrotechnic; shock; wavelets; shock response spectrum; data correction AB We are sometimes presented with data with serious flaws, like saturation, over-range, zero shifts, and impulsive noise, including much of the available pyrotechnic data. Obviously, these data should not be used if at all possible. However, we are sometimes forced to use these data as the only data available. A method to salvage these data using wavelets is discussed. The results must be accepted with the understanding that the.answers are credible, not necessarily correct. None of the methods will recover information lost due to saturation and over-range with the subsequent nonlinear behavior of the data acquisition system. The results are illustrated using analytical examples and flawed pyrotechnic data. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Smallwood, DO (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU INST ENVIRONMENTAL SCIENCES PI MT PROSPECT PA 940 E NORTHWEST HIGHWAY, MT PROSPECT, IL 60056 USA BN 1-877862-63-0 PY 1998 BP 79 EP 86 PG 4 WC Acoustics; Environmental Sciences; Instruments & Instrumentation SC Acoustics; Environmental Sciences & Ecology; Instruments & Instrumentation GA BL14X UT WOS:000074492400010 ER PT S AU Cooper, PS AF Cooper, PS BE Corral, GH Aquina, MS TI High speed data acquisition SO INSTRUMENTATION IN ELEMENTARY PARTICLE PHYSICS: THE VII ICFA SCHOOL SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ICFA School on Instrumentation 1997 CY JUL 07-19, 1997 CL LEON, MEXICO SP ICFA Comm, Panel Instrumentat Innovat & Dev, Univ Guanajuato Leon, Mexican Phys Soc, Div Particles & Fields, Ctr Investigac & Estudios Avanzados, Mexico City AB A general introduction to high Speed data acquisition system techniques in modern particle physics experiments is given. Examples are drawn from the SELEX(E781) high statistics charmed baryon production and decay experiment taking data at Fermilab. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Cooper, PS (reprint author), Fermi Natl Accelerator Lab, MS122,POB 500, Batavia, IL 60510 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-763-4 J9 AIP CONF PROC PY 1998 IS 422 BP 3 EP 13 PG 11 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BK87F UT WOS:000073721000001 ER PT S AU Va'vra, J AF Va'vra, J BE Corral, GH Aquina, MS TI Gaseous wire detectors SO INSTRUMENTATION IN ELEMENTARY PARTICLE PHYSICS: THE VII ICFA SCHOOL SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ICFA School on Instrumentation 1997 CY JUL 07-19, 1997 CL LEON, MEXICO SP ICFA Comm, Panel Instrumentat Innovat & Dev, Univ Guanajuato Leon, Mexican Phys Soc, Div Particles & Fields, Ctr Investigac & Estudios Avanzados, Mexico City AB This article represents a series of three lectures describing topics needed to understand the design of typical gaseous wire detectors used in large high energy physics experiments; including the electrostatic design, drift of electrons in the electric and magnetic field, the avalanche, signal creation, limits on the position accuracy as well as some problems one encounters in practical operations. Reader should also refer to Ref. 1-4. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Va'vra, J (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-763-4 J9 AIP CONF PROC PY 1998 IS 422 BP 117 EP 187 PG 71 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BK87F UT WOS:000073721000004 ER PT S AU Atac, M AF Atac, M BE Corral, GH Aquina, MS TI Visible light photon counters (VLPCs) for high rate tracking medical imaging and particle astrophysics SO INSTRUMENTATION IN ELEMENTARY PARTICLE PHYSICS: THE VII ICFA SCHOOL SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ICFA School on Instrumentation 1997 CY JUL 07-19, 1997 CL LEON, MEXICO SP ICFA Comm, Panel Instrumentat Innovat & Dev, Univ Guanajuato Leon, Mexican Phys Soc, Div Particles & Fields, Ctr Investigac & Estudios Avanzados, Mexico City AB This paper is on the operation principles of the Visible Light Photon Counters (VLPCs), application to high luminosity-high multiplicity tracking for High Energy Charged Particle Physics, and application to Medical Imaging and Particle Astrophysics. The VLPCs as Solid State Photomultipliers (SSPMs) with high quantum efficiencycan detect down to single photons very efficiently with excellent time resolution and high avalanche gains. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Atac, M (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-763-4 J9 AIP CONF PROC PY 1998 IS 422 BP 191 EP 207 PG 17 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BK87F UT WOS:000073721000005 ER PT S AU Atac, M Streets, J Wilcer, N AF Atac, M Streets, J Wilcer, N BE Corral, GH Aquina, MS TI Detection of cosmic ray tracks using scintillating fibers and position sensitive multi-anode photomultipliers SO INSTRUMENTATION IN ELEMENTARY PARTICLE PHYSICS: THE VII ICFA SCHOOL SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ICFA School on Instrumentation 1997 CY JUL 07-19, 1997 CL LEON, MEXICO SP ICFA Comm, Panel Instrumentat Innovat & Dev, Univ Guanajuato Leon, Mexican Phys Soc, Div Particles & Fields, Ctr Investigac & Estudios Avanzados, Mexico City AB This experiment demonstrates detection of cosmic ray tracks by using scintillating fiber planes and multi-anode photomultipliers (MA-PMTs). In laboratory like this, cosmic rays provide a natural source of high-energy charged particles which can be detected with high efficiency and with nanosecond time resolution. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Atac, M (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-763-4 J9 AIP CONF PROC PY 1998 IS 422 BP 251 EP 256 PG 6 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BK87F UT WOS:000073721000009 ER PT S AU Johnson, M Sheaff, M AF Johnson, M Sheaff, M BE Corral, GH Aquina, MS TI Use of de-randomizing buffers in a data acquisition system SO INSTRUMENTATION IN ELEMENTARY PARTICLE PHYSICS: THE VII ICFA SCHOOL SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ICFA School on Instrumentation 1997 CY JUL 07-19, 1997 CL LEON, MEXICO SP ICFA Comm, Panel Instrumentat Innovat & Dev, Univ Guanajuato Leon, Mexican Phys Soc, Div Particles & Fields, Ctr Investigac & Estudios Avanzados, Mexico City AB This is the course manual for a laboratory course that was designed to demonstrate a basic technique employed in data acquisition systems for the purpose of reducing deadtime and thereby increasing throughput. A custom CAMAC module was designed and built at Fermilab for use in these measurements. The use of queueing theory to predict the performance of the system is discussed, including some equations which can be used for that purpose. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Johnson, M (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-763-4 J9 AIP CONF PROC PY 1998 IS 422 BP 313 EP 323 PG 11 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BK87F UT WOS:000073721000012 ER PT S AU Schwiening, J AF Schwiening, J BE Corral, GH Aquina, MS TI DIRC, the internally reflecting ring imaging Cerenkov detector for BABAR: Properties of the quartz radiators SO INSTRUMENTATION IN ELEMENTARY PARTICLE PHYSICS: THE VII ICFA SCHOOL SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ICFA School on Instrumentation 1997 CY JUL 07-19, 1997 CL LEON, MEXICO SP ICFA Comm, Panel Instrumentat Innovat & Dev, Univ Guanajuato Leon, Mexican Phys Soc, Div Particles & Fields, Ctr Investigac & Estudios Avanzados, Mexico City C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Schwiening, J (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-763-4 J9 AIP CONF PROC PY 1998 IS 422 BP 407 EP 408 PG 2 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BK87F UT WOS:000073721000029 ER PT S AU Tassotto, G AF Tassotto, G BE Corral, GH Aquina, MS TI Segmented wire ion chambers (SWICs) used as proton beam position/profile detectors in the fixed target beamlines at Fermilab SO INSTRUMENTATION IN ELEMENTARY PARTICLE PHYSICS: THE VII ICFA SCHOOL SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT ICFA School on Instrumentation 1997 CY JUL 07-19, 1997 CL LEON, MEXICO SP ICFA Comm, Panel Instrumentat Innovat & Dev, Univ Guanajuato Leon, Mexican Phys Soc, Div Particles & Fields, Ctr Investigac & Estudios Avanzados, Mexico City AB Segmented Wire Ion Chambers have been used at Fermilab since 1972 to monitor the profile of the proton beams in the various beamlines. Many modifications and improvements have been made since thai time. SWICs are presently used to display beam profiles at intensities from 10(6) to over 10(13) particles/sec. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Tassotto, G (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-763-4 J9 AIP CONF PROC PY 1998 IS 422 BP 409 EP 413 PG 5 WC Instruments & Instrumentation; Physics, Particles & Fields SC Instruments & Instrumentation; Physics GA BK87F UT WOS:000073721000030 ER PT J AU Vo-Dinh, T Isola, N Alarie, JP Landis, D Griffin, GD Allison, S AF Vo-Dinh, T Isola, N Alarie, JP Landis, D Griffin, GD Allison, S TI Development of a multiarray biosensor for DNA diagnostics SO INSTRUMENTATION SCIENCE & TECHNOLOGY LA English DT Article ID POLYMERASE; PROBES AB This work involves the development and evaluation of a multiarray biosensor for DNA diagnostics. The evaluation of various system components developed for the biosensor is discussed. The DNA probes labeled with visible and near infrared (NIR) dyes are evaluated. The detection system uses a two-dimensional charge-coupled device (CCD). Examples of application of gene probes in DNA hybridization experiments and in biomedical diagnosis (detection of the p53 cancer gene) are presented to illustrate the usefulness and potential of the biosensor device. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 14 TC 13 Z9 14 U1 0 U2 2 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1073-9149 J9 INSTRUM SCI TECHNOL JI Instrum. Sci. Technol. PY 1998 VL 26 IS 5 BP 503 EP 514 DI 10.1080/10739149808000917 PG 12 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA 139HE UT WOS:000077021800005 ER PT S AU Carr, R Ravi, R AF Carr, R Ravi, R BE Bixby, RE Boyd, EA RiosMercado, RZ TI A new bound for the 2-Edge Connected Subgraph Problem SO INTEGER PROGRAMMING AND COMBINATORIAL OPTIMIZATION SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 6th International Integer Programming and Combinatorial Optimization (IPCO VI) CY JUN 22-24, 1998 CL HOUSTON, TEXAS ID NETWORKS; PROPERTY; TSP AB Given a complete undirected graph with non-negative costs on the edges, the 2-Edge Connected Subgraph Problem consists in finding the minimum cost spanning 2-edge connected subgraph (where multi-edges are allowed in the solution). A lower bound for the minimum cost 2-edge connected subgraph is obtained by solving the linear programming relaxation for this problem, which coincides with the subtour relaxation of the traveling salesman problem when the costs satisfy the triangle inequality. The simplest fractional solutions to the subtour relaxation are the 1/2-integral solutions in which every edge variable has a value which is a multiple of 1/2. We show that the minimum cost of a 2-edge connected subgraph is at most four-thirds the cost of the minimum, cost 1/2-integral solution of the subtour relaxation. This supports the long-standing 4/3 Conjecture for the TSP, which states that there is a Hamilton cycle which is within 4/3 times the cost of the optimal subtour relaxation solution when the costs satisfy the triangle inequality. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Carnegie Mellon Univ, GSIA, Pittsburgh, PA USA. RP Carr, R (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 17 TC 7 Z9 7 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-64590-X J9 LECT NOTES COMPUT SC PY 1998 VL 1412 BP 112 EP 125 PG 14 WC Computer Science, Theory & Methods; Engineering, Industrial; Operations Research & Management Science; Mathematics, Applied SC Computer Science; Engineering; Operations Research & Management Science; Mathematics GA BM08R UT WOS:000077582600009 ER PT J AU Auciello, O AF Auciello, O TI Proceedings of the Tenth International Symposium on Integrated Ferroelectrics - Monterey, California, USA March 1-4, 1998 - Part II SO INTEGRATED FERROELECTRICS LA English DT Editorial Material C1 Argonne Natl Lab, ISIF98, Tech Program, Argonne, IL 60439 USA. RP Auciello, O (reprint author), Argonne Natl Lab, ISIF98, Tech Program, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 22 IS 1-4 BP XIX EP XXIX PG 11 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 130WX UT WOS:000076544300001 ER PT J AU Lakeman, CDE Boyle, TJ Rodriguez, MA AF Lakeman, CDE Boyle, TJ Rodriguez, MA TI Chemical solution deposition of SrBi2Ta2O9 (SBT) films for non-volatile memory applications SO INTEGRATED FERROELECTRICS LA English DT Article DE SrBi2Ta2O9; SBT; thin film; substrate; chemical solution deposition; CSD; composition; processing ID THIN-FILMS; FERROELECTRIC PROPERTIES; TEMPERATURE; DEPENDENCE; FATIGUE AB SrBi2Ta2O9 (SBT) films have received considerable attention for use as nonvolatile memory elements. We have developed a process to prepare SET films with good ferroelectric properties at low temperatures. In this paper, we will present strategies used to optimize the properties of the films including film composition, the nature of the substrate (or bottom electrode) used, and the thermal processing cycle. Under appropriate conditions, similar to 1700 Angstrom films can be prepared which have a large switchable polarization (2P(sw) >10 mu C/cm(2)), and an operating voltage less than or equal to 2.0V. C1 Texas Instruments Inc, Dallas, TX 75265 USA. Sandia Natl Labs, Adv Mat Lab, Albuquerque, NM 87106 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lakeman, CDE (reprint author), Texas Instruments Inc, POB 655012,Mail Stop 921, Dallas, TX 75265 USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 22 IS 1-4 BP 565 EP 573 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 130WX UT WOS:000076544300006 ER PT J AU Im, J Krauss, AR Auciello, O Gruen, DM Chang, RPH AF Im, J Krauss, AR Auciello, O Gruen, DM Chang, RPH TI Mass spectroscopy of recoiled ion investigation of electrode segregation effects during the initial stages of SrBi2Ta2O9 film growth SO INTEGRATED FERROELECTRICS LA English DT Article DE ferroelectric films; SrBi2Ta2O9; Pt/Ti electrodes ID BEAM SURFACE-ANALYSIS; TIME-OF-FLIGHT; IN-SITU; REAL-TIME; SBT AB The thermodynamic stability of Pt/Ti/SiO2/Si, Pt/TiO2/SiO2/Si, Pt/Ta/SiO2/Si, Ir/SiO2/Si, and RuO2/SiO2/Si electrode layers has been studied using mass spectroscopy of recoiled ions (MSRI), a new technique which provides monolayer-specific in situ surface analysis under conditions of modest oxygen partial pressures required for oxide film growth using sputter-deposition. Results of the initial stages of growth of SrBi2Ta2O9 films on the various substrates listed above are presented also. It is found that the initial growth of SrBi2Ta2O9 films strongly depends on the composition of the bottom electrode surface, on diffusion and segregation processes, and the presence of reactive species on the electrode surface. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Northwestern Univ, Dept Mat Sci, Evanston, IL 60208 USA. RP Im, J (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Chang, R.P.H/B-7505-2009 NR 15 TC 0 Z9 0 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 22 IS 1-4 BP 743 EP 755 PG 13 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 130WX UT WOS:000076544300022 ER PT J AU Findikoglu, AT Jia, QX Reagor, DW Fan, Y Lythe, GD Camassa, RA Cai, D Gronbech-Jensen, N Bishop, AR AF Findikoglu, AT Jia, QX Reagor, DW Fan, Y Lythe, GD Camassa, RA Cai, D Gronbech-Jensen, N Bishop, AR TI New potential applications of nonlinear dielectrics: Microwave solitons and stochastic resonance SO INTEGRATED FERROELECTRICS LA English DT Article DE nonlinear dielectrics; strontium titanate; high-temperature superconductors; microwave solitons; stochastic resonance AB Nonlinear dielectrics, such as SrTiO3 (STO), present unique opportunity not only to develop practical electrically tunable devices, but also to explore novel scientific and technological concepts that exploit strong nonlinearities in these materials. Using prototype device structures, we are currently investigating two interesting phenomena in the realm of nonlinearity: microwave solitons and stochastic resonance. Microwave solitons are similar to optical solitons and are formed when a specific dispersion is introduced into the medium to counteract and balance the effect of nonlinearity for certain waveforms. Stochastic resonance is a phenomenon in which random noise plays a constructive role and enhances a nonlinear system's response to a deterministic signal. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Findikoglu, AT (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Jia, Q. X./C-5194-2008 NR 11 TC 8 Z9 8 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 22 IS 1-4 BP 779 EP 788 PG 10 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 130WX UT WOS:000076544300025 ER PT J AU Gopalan, V Mitchell, TE Sickafus, KE Jia, QX AF Gopalan, V Mitchell, TE Sickafus, KE Jia, QX TI Real-time study of kinetics of 180 degrees domains in congruent LiTaO3 under an external field SO INTEGRATED FERROELECTRICS LA English DT Article DE LiTaO3; ferroelectrics; domains; kinetics; wall energy; critical nucleus AB The growth of ferroelectric 180 degrees domains in congruent LiTaO3 under an external field has been studied using light microscopy at room temperature. The wall velocity shows an exponential behavior with external field. The estimated wall energy is 35 mJ/m(2) at room temperature. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Gopalan, V (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Jia, Q. X./C-5194-2008 NR 6 TC 0 Z9 0 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 22 IS 1-4 BP 925 EP 929 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 130WX UT WOS:000076544300038 ER PT J AU Gopalan, V Mitchell, TE Jia, QX Robinson, JM Kawas, M Schlesinger, TE Stancil, DD AF Gopalan, V Mitchell, TE Jia, QX Robinson, JM Kawas, M Schlesinger, TE Stancil, DD TI Ferroelectrics as a versatile solid state platform for integrated optics SO INTEGRATED FERROELECTRICS LA English DT Article DE LiTaO3; LiNbO3; ferroelectrics; integrated optics; electro-optic scanners; second harmonic generators ID DOMAIN INVERSION; LITAO3; CRYSTALS AB A high speed electro-optic scanner is demonstrated on a ferroelectric LiTaO3 crystal. The scanner shows a deflection of 39.5 mrad/kV, 13 resolvable spots per kV, and shows no degradation of performance up to 10MHz of driving field. Integration of the scanner with quasi-phase-matched frequency doublers and lenses is discussed. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Carnegie Mellon Univ, Ctr Data Storage Syst, Pittsburgh, PA 15213 USA. RP Gopalan, V (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Stancil, Daniel/D-1339-2013; Jia, Q. X./C-5194-2008 OI Stancil, Daniel/0000-0002-2010-1381; NR 7 TC 3 Z9 3 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 22 IS 1-4 BP 985 EP 991 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 130WX UT WOS:000076544300044 ER PT J AU Auciello, O AF Auciello, O TI Proceedings of the Tenth International Symposium on Integrated Ferroelectrics - Monterey, California, USA - March 1-4, 1998 SO INTEGRATED FERROELECTRICS LA English DT Editorial Material C1 Argonne Natl Lab, Tech Program, ISIF98, Argonne, IL 60439 USA. RP Auciello, O (reprint author), Argonne Natl Lab, Tech Program, ISIF98, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 21 IS 1-4 BP XI EP XXI PG 11 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 130WV UT WOS:000076544100001 ER PT J AU Bai, GR Wang, A Tsu, IF Foster, CM Auciello, O AF Bai, GR Wang, A Tsu, IF Foster, CM Auciello, O TI In-situ low temperature growth and orientation control in MOCVD PZT/RuO2 thin film heterostructures on SiO2/Si substrates SO INTEGRATED FERROELECTRICS LA English DT Article DE ferroelectric; thin films; RuO2; PZT; MOCVD ID CHEMICAL-VAPOR-DEPOSITION; ELECTRICAL-PROPERTIES; CAPACITORS; RUO2; ELECTRODES; RUTHENIUM; FATIGUE AB Pb(Zr0.5Ti0.5)O-3/RuO2 (PZT/RuO2) thin film heterostructures with controlled PZT and RuO2 orientation were successfully grown in-situ on SiO2/(001)Si substrates at 525 degrees C, using metal-organic chemical vapor deposition (MOCVD). XRD analysis revealed that the textured orientation of the PZT films is strongly dependent on the orientation of RuO2 bottom electrode layers, PZT layers grown on (101)-textured RuO2 exhibit a predominant (001) orientation, while those grown on (110)-textured RuO2 present a mixed (001)-(111)-(110) polycrystalline structure. Highly (110)oriented RuO2 layers were grown using relatively high deposition temperatures and low rates (similar to 350 degrees C and < 3 nm/min, respectively), while (101)-textured RuO2 layers were grown at slightly lower temperatures and higher deposition rates than those for (110) layers (i.e., similar to 300 degrees C and > 3 nm/min, respectively). The RuO2 layers exhibited resistivities of 34-40 mu Omega-cm, average grain size of 65+/-15 nm, and surface roughness of 3-10 nm (rms), while the PZT layers were dense with average grain size of 150-250 nm. Ag/PZT (001)/RuO2(101) capacitors exhibited remanent polarization, saturation polarization, and coercive field of 49.7 mu C/cm(2), 82.5 mu C/cm(2), and 35.0 kv/cm, respectively, while the values for Ag/PZT (001-111-110)/RuO2(110) capacitors were 21.5 mu C/cm(2), 35.4 mu C/cm(2), and 39.0 kv/cm, respectively. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Bai, GR (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 30 TC 7 Z9 7 U1 0 U2 1 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 21 IS 1-4 BP 291 EP 304 DI 10.1080/10584589808202071 PG 14 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 130WV UT WOS:000076544100027 ER PT J AU Jia, QX Roper, JM Arendt, PN Foltyn, SR Fan, Y Groves, JR AF Jia, QX Roper, JM Arendt, PN Foltyn, SR Fan, Y Groves, JR TI Oriented conductive oxide electrodes on SiO2/Si SO INTEGRATED FERROELECTRICS LA English DT Article DE conductive oxides; RuO2; La0.5Sr0.5CoO3; thin film deposition ID RUO2 THIN-FILMS; ELECTRICAL-PROPERTIES; RUTHENIUM DIOXIDE; SI; DEPOSITION; GROWTH; BA0.5SR0.5TIO3; CAPACITORS AB Highly conductive biaxially textured (both normal to and in the film plane) RuO2 and La0.5Sr0.5CoO3 thin films have been deposited on SiO2/Si substrates for the first time. Yttria-stabilized zirconia (YSZ) produced by ion-beam-assisted-deposition (IBAD) is used as a seed layer to induce the biaxial texture of RuO2 and/or La0.5Sr0.5CoO3 on amorphous SiO2/Si. The degree of in-plane texture of the conductive oxide films is directly related to the texture of IBAD-YSZ. The biaxially oriented RuO2 and La0.5Sr0.5CoO3 films have a metallic resistivity vs temperature characteristic and a room-temperature resistivity of 37 mu Omega-cm and 110 mu Omega-cm, respectively. Ba0.5Sr0.5TiO3 thin films deposited on SiO2/Si using biaxially oriented RuO2 and La0.5Sr0.5CoO3 as bottom electrodes are(111) and (110) oriented, respectively. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Jia, QX (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Mail Stop K763, Los Alamos, NM 87545 USA. RI Jia, Q. X./C-5194-2008 NR 21 TC 0 Z9 0 U1 0 U2 1 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 21 IS 1-4 BP 397 EP 406 DI 10.1080/10584589808202080 PG 10 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 130WV UT WOS:000076544100036 ER PT J AU Speck, JS Pomp, W Romanov, AE Foster, CM AF Speck, JS Pomp, W Romanov, AE Foster, CM TI Domain pattern formation in epitaxial ferroelectric films SO INTEGRATED FERROELECTRICS LA English DT Article C1 Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. Tech Univ Dresden, D-01069 Dresden, Germany. AF Ioffe Physicotech Inst, St Petersburg 194021, Russia. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Speck, JS (reprint author), Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. RI Speck, James/H-5646-2011 NR 0 TC 0 Z9 0 U1 1 U2 1 PU GORDON BREACH PUBLISHING, TAYLOR & FRANCIS GROUP PI PHILADELPHIA PA 325 CHESTNUT ST, 8TH FL, PHILADELPHIA, PA 19106 USA SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 20 IS 1-4 BP 67 EP 68 DI 10.1080/10584589808238767 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA V2727 UT WOS:000168669700007 ER PT J AU Gruverman, A Auciello, O Tokumoto, H AF Gruverman, A Auciello, O Tokumoto, H TI Scanning force microscopy: Application to nanoscale studies of ferroelectric domains SO INTEGRATED FERROELECTRICS LA English DT Article DE SFM; ferroelectric domains; thin films piezoelectricity; nanostructures ID ELECTRICALLY POLAR SUBSTANCES; TRIGLYCINE SULFATE; THIN-FILMS; MEASUREMENT SIGNALS; PB(ZR,TI)O-3 FILMS; LOCALIZED CHARGE; SURFACE; FATIGUE; CRYSTALS; FRICTION AB Recent advances in nanoscale studies of ferroelectric domains by means of scanning force microscopy (SFM) are reviewed with particular emphasis on investigation of domain structure and polarization reversal in ferroelectric thin films. Applicability of different SFM modes to domain imaging with respect to the physical properties of ferroelectrics is discussed. Examples shown here include results on domain structure observation in single crystals and films by SFM operating in the noncontact, friction, topographic and piezoresponse modes. Domain wall dynamics and fatigue effects as well as SFM spatial resolution of domain structure in thin films are addressed. C1 Angstrom Technol Partnership, Joint Res Ctr Atom Technol, Tsukuba, Ibaraki 305, Japan. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. JRCAT, Natl Inst Adv Interdisciplinary Res, Tsukuba, Ibaraki 305, Japan. RP Angstrom Technol Partnership, Joint Res Ctr Atom Technol, Higashi 1-1-4, Tsukuba, Ibaraki 305, Japan. EM alexei@src.sony.co.jp RI Gruverman, alexei/P-3537-2014 OI Gruverman, alexei/0000-0003-0492-2750 NR 55 TC 63 Z9 63 U1 4 U2 11 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 1058-4587 EI 1607-8489 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 19 IS 1-4 BP 49 EP 83 DI 10.1080/10584589808012695 PG 35 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA ZU661 UT WOS:000074220500004 ER PT J AU Jia, QX Findikoglu, AT Zhou, R Foltyn, SR Wu, XD Smith, JL Wang, Q Evans, DF Gladfelter, WL AF Jia, QX Findikoglu, AT Zhou, R Foltyn, SR Wu, XD Smith, JL Wang, Q Evans, DF Gladfelter, WL TI Structural and dielectric properties of Ba0.5Sr0.5TiO3 thin films with an EPI-RuO2 bottom electrode SO INTEGRATED FERROELECTRICS LA English DT Article DE DRAMs; BSTO; thin film ID PULSED-LASER DEPOSITION; ELECTRICAL-PROPERTIES; HETEROEPITAXIAL GROWTH; STRONTIUM-TITANATE; RUO2; CAPACITORS; OXIDE; SR0.5BA0.5TIO3; CONSTANT; SAPPHIRE AB Epitaxial conductive RuO2 thin films were used as bottom electrodes of Ba0.5Sr0.5TiO3 (BSTO) thin-film capacitors. The BSTO showed pure (111) orientation normal to the substrate surface when grown on (200) oriented epi-RuO2 on LaAlO3. The BSTO film consisted of a main body of stoichiometric bulk layer and a slightly oxygen deficiency region on the very film surface as revealed by Rutherford backscattering spectrometry. The dielectric constant of BSTO was above 400 at 10 kHz with zero dc electric field bias. A bias de electric field modulation of the dielectric constant was observed to be more than 80% at 100 kHz at a held intensity of 6x10(5) V/cm. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Minnesota, Dept Mat Sci & Chem Engn, Minneapolis, MN 55455 USA. RP Jia, QX (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Mail Stop K763, Los Alamos, NM 87545 USA. RI Jia, Q. X./C-5194-2008 NR 19 TC 1 Z9 1 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 1998 VL 19 IS 1-4 BP 111 EP 119 DI 10.1080/10584589808012698 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA ZU661 UT WOS:000074220500007 ER PT S AU Jia, QX Reagor, D Findikoglu, AT Mombourquette, C AF Jia, QX Reagor, D Findikoglu, AT Mombourquette, C BE Pandey, RK Witter, DE Varshney, U TI Integrated thin films for Josephson junctions, SQUIDs, and electrically tunable microwave devices SO INTEGRATED THIN FILMS AND APPLICATIONS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT Symposium on Integrated Thin Films and Applications, at the 99th Annual Meeting of the American-Ceramic-Society CY MAY 04-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc AB Josephson junctions and superconducting quantum interference devices (SQUIDs) have found many applications in different fields. By engineering the high-temperature superconductor (S) electrodes (YBa2Cu3O7-x) and normal-metal (N) barrier layers (PrBa2Cu3O7-x), we have fabricated high performance ramp edge-geometry SNS Josephson junctions and SQUIDs. We also designed and fabricated prototype electrically tunable microwave devices, including phase shifters, mixers, and bandpass filters. These are fabricated by integrating high-temperature superconducting YBa2Cu3O7-x and nonlinear dielectric SrTiO3 thin films. C1 Univ Calif Los Alamos Natl Lab, Dept Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Jia, QX (reprint author), Univ Calif Los Alamos Natl Lab, Dept Mat Sci & Technol, MS K763, Los Alamos, NM 87545 USA. RI Jia, Q. X./C-5194-2008 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-032-7 J9 CERAM TRANS PY 1998 VL 86 BP 61 EP 72 PG 12 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BL05W UT WOS:000074135200005 ER PT S AU Hawley, ME Brown, GW Hundley, MF Thompson, JD Hristova, DK Tesmer, J Jia, QX Peterson, EJ AF Hawley, ME Brown, GW Hundley, MF Thompson, JD Hristova, DK Tesmer, J Jia, QX Peterson, EJ BE Pandey, RK Witter, DE Varshney, U TI Growth-related magnetic and physical structures in CMR films SO INTEGRATED THIN FILMS AND APPLICATIONS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT Symposium on Integrated Thin Films and Applications, at the 99th Annual Meeting of the American-Ceramic-Society CY MAY 04-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc AB Scanning tunneling microscopy (STM), atomic force microscopy (AFM), and magnetic force microscopy (MFM) have proven to be powerful tools for revealing property-sensitive structures in magnetic materials. With the renewed interest in perovskite films as materials for read-heads in high-density magnetic data storage, the same challenges faced by high temperature superconductor (HTS) film fabrication are repeated for these materials. To begin addressing these challenges, we used vapor phase epitaxy to fabricate La (Sr, Ca) based manganate films on single crystal perovskite substrates under different conditions and characterized them with scanning probe microscopies, x-ray diffraction, and temperature-dependent magnetization and resistivity measurements (M(T) and rho(T)). The as-grown films were polygranular with grain sizes increasing with increasing temperature (T). The post-deposition annealed films consisted of coalesced layers with improved transport properties. The room temperature magnetic structure of the Sr-based films appeared to be related to defects and/or strain. C1 Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RP Hawley, ME (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, MS K765, Los Alamos, NM 87545 USA. RI Jia, Q. X./C-5194-2008 NR 0 TC 2 Z9 2 U1 1 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-032-7 J9 CERAM TRANS PY 1998 VL 86 BP 127 EP 143 PG 17 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BL05W UT WOS:000074135200011 ER PT S AU Schneider, JA McCarty, KF Heffelfinger, JR Moody, NR AF Schneider, JA McCarty, KF Heffelfinger, JR Moody, NR BE Pandey, RK Witter, DE Varshney, U TI Nanoindentation characterization of aluminum nitride thin films on sapphire substrates SO INTEGRATED THIN FILMS AND APPLICATIONS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT Symposium on Integrated Thin Films and Applications, at the 99th Annual Meeting of the American-Ceramic-Society CY MAY 04-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc AB The hardness and elastic moduli were calculated for polycrystalline ALN substrates and epitaxial ALN films on sapphire substrates based on nanoindentation tests. Hardness and elastic moduli calculated for the polycrystalline ALN substrates as well as thick (800 nm) epitaxial ALN films on sapphire agree with the published values for bulk AIN samples. For thinner (50 - 110 nm) epitaxial AIN films deposited on sapphire, the measured hardness and elastic moduli initially match the polycrystalline AIN values and increase with indentation distances to values expected for the (0001) oriented sapphire. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Schneider, JA (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. RI McCarty, Kevin/F-9368-2012 OI McCarty, Kevin/0000-0002-8601-079X NR 0 TC 0 Z9 0 U1 0 U2 4 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-032-7 J9 CERAM TRANS PY 1998 VL 86 BP 255 EP 263 PG 9 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BL05W UT WOS:000074135200020 ER PT S AU Spelt, PF Kirson, AM Scott, S AF Spelt, PF Kirson, AM Scott, S GP NRC TI New vehicle data bus architecture and in-vehicle information system evaluation platform for intelligent transportation systems modules SO INTELLIGENT TRANSPORTATION SYSTEMS, AUTOMATED HIGHWAY SYSTEMS, TRAVELER INFORMATION, AND ARTIFICIAL INTELLIGENCE SE TRANSPORTATION RESEARCH RECORD LA English DT Article; Proceedings Paper CT 77th Annual Meeting of the Transportation-Research-Board CY JAN, 1998 CL WASHINGTON, D.C. SP Transportat Res Board AB An increasing number of intelligent transportation systems-(ITS-) after-market systems present a set of in-vehicle installation and use problems relatively unique in the history of automobile use. Many automobile manufacturers would like to offer these new state-of-the-art devices to customers, but are hampered by the current design cycle of new cars. While automobile manufacturers are indeed using multiplex buses [the automotive equivalent of a computer local area network (LAN)], problems remain because manufacturers are not converging on a single bus standard. A new dual-bus architecture to address these problems is presented with an in-vehicle information system (IVIS) research platform on which the principles embodied in the ITS data bus architecture can be evaluated. The dual-bus architecture has been embodied in a proposed Society of Automotive Engineers (SAE) standard, with support from both automobile and consumer electronics manufacturers. The architecture and a reference model for the interfaces and protocols of the new bus are presented and described. The goals of the ITS data bus are to be inexpensive and easy to install, and to provide for safe and secure functioning. These high-level goals are embodied in the proposed standard. The IVIS development platform comprises a number of personal computers (PCs) linked via ethernet LAN, with a high-end PC serving as the IVIS computer. In this LAN, actual devices can be inserted in place of the original PC that emulated them. This platform will serve as the development and test bed for an ITS data bus conformity test, the SAE standard for which is also being developed. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Motorola Inc, Northbrook, IL 60062 USA. Jet Prop Lab, Washington, DC 20024 USA. RP Spelt, PF (reprint author), Oak Ridge Natl Lab, POB 2008,Bldg 6025,MS 6364, Oak Ridge, TN 37831 USA. NR 10 TC 0 Z9 0 U1 1 U2 2 PU NATL ACAD SCI PI WASHINGTON PA 2101 CONSTITUTION AVE, WASHINGTON, DC 20418 USA SN 0361-1981 BN 0-309-06523-2 J9 TRANSPORT RES REC PY 1998 IS 1651 BP 17 EP 22 PG 6 WC Engineering, Civil; Transportation SC Engineering; Transportation GA BN49C UT WOS:000082031200003 ER PT J AU von Winterfeldt, D Schweitzer, E AF von Winterfeldt, D Schweitzer, E TI An assessment of tritium supply alternatives in support of the US nuclear weapons stockpile SO INTERFACES LA English DT Article AB Nuclear weapons require the periodic replacement of tritium, a radioactive gas that decays at approximately 5.5 percent per year. Currently no tritium-supply facility exists in the US, and due to the decay, the tritium inventory will fall below the required reserve level in 2011. To decide how to fill this projected gap, the US Department of Energy assessed 10 tritium-supply alternatives, including several types of new reactors, an accelerator, and the use of commercial reactors. The DOE compared the alternatives with respect to three objectives: production assurance, cost, and environmental impacts. We combined a dynamic production-simulation model and probabilistic assessments of schedule, production capacity, and availability risks to predict the production behavior of each alternative over 40 years. We also assessed the cost and environmental risks. The secretary of energy decided to pursue both the commercial-reactor and accelerator alternatives, based, in part, on the results of this analysis. C1 Decis Insights Inc, Irvine, CA 92612 USA. US DOE, Off Def Programs, Washington, DC 20585 USA. RP von Winterfeldt, D (reprint author), Decis Insights Inc, 2062 Business Ctr Dr,Suite 110, Irvine, CA 92612 USA. NR 13 TC 7 Z9 7 U1 2 U2 5 PU INST OPERATIONS RESEARCH MANAGEMENT SCIENCES PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2909 USA SN 0092-2102 J9 INTERFACES JI Interfaces PD JAN-FEB PY 1998 VL 28 IS 1 BP 92 EP 112 DI 10.1287/inte.28.1.92 PG 21 WC Management; Operations Research & Management Science SC Business & Economics; Operations Research & Management Science GA ZN901 UT WOS:000073694900009 ER PT B AU Saiz, E Tomsia, AP Cannon, RM AF Saiz, E Tomsia, AP Cannon, RM BE Bellosi, A Kosmac, T Tomsia, AP TI Diffusion processes at liquid metal/ceramic interfaces SO INTERFACIAL SCIENCE IN CERAMIC JOINING SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Interfacial Science in Ceramic Joining CY NOV 12-15, 1997 CL BLED, SLOVENIA SP NATO Sci Affairs Div, Brussels, IRTEC-Res Inst Ceramics Technol, Faenza, Jozef Stefan Inst, Ljubljana, Lawrence Berkeley Natl Lab, Berkeley AB Experiments with molten drops of non-reactive metals (Au, Cu, Ni) on pure, polycrystalline alumina have been performed in Ar. Afterwards the metal drops have been removed, and the grain boundary grooves at the interface analyzed by AFM and SEM to identify and study the atomic transport mechanisms at the metal/oxide interface. The grooves exhibit shapes expected for diffusion controlled growth; the interfaces are less faceted than the Al2O3 surfaces. The time dependence for grooving at the Ni/Al2O3 interface indicates that diffusion through the molten liquid is the main atomic transport mechanism. Transport rates near the interface are two to four orders of magnitude faster than on the surface of the oxide. Experiments performed with gold on Al2O3 have shown that the transport is much faster in air than in inert atmospheres underlining a dramatic influence of the environment on interfacial mass transport. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Saiz, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-5221-1 J9 NATO ASI 3 HIGH TECH PY 1998 VL 58 BP 161 EP 168 PG 8 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BM15W UT WOS:000077846500014 ER PT B AU Loehman, RE Glass, SJ Quillen, BG Mahoney, FM Hosking, FM Stephens, JJ Vianco, PT Pollinger, J AF Loehman, RE Glass, SJ Quillen, BG Mahoney, FM Hosking, FM Stephens, JJ Vianco, PT Pollinger, J BE Bellosi, A Kosmac, T Tomsia, AP TI Interfaces in high-strength, high-temperature ceramic joints SO INTERFACIAL SCIENCE IN CERAMIC JOINING SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Interfacial Science in Ceramic Joining CY NOV 12-15, 1997 CL BLED, SLOVENIA SP NATO Sci Affairs Div, Brussels, IRTEC-Res Inst Ceramics Technol, Faenza, Jozef Stefan Inst, Ljubljana, Lawrence Berkeley Natl Lab, Berkeley AB Development of stronger, more refractory joints in non-oxide ceramics has been accompanied by a better understanding of diffusion and reactivity at ceramic interfaces. Control of the chemistry and interfacial reactivity of refractory oxide joining compositions has produced silicon nitride joints with four-point bend strengths of 550 MPa at 1000 degrees C. The oxide compositions were chosen to be compatible with the silicon nitride grain boundary phase, which enhances bond strength. Au-Pd braze alloys with small additions of V have been used to join silicon nitride between 1200 and 1300 degrees C, giving strengths of 520 MPa at room temperature. Microprobe and SEM analysis suggests the interfacial reaction is Si3N4 + 6Pd + 4V = 4VN + 3Pd(2)Si. Initial tests of the suitability of both the refractory oxide and Au-Pd-V compositions for joining SiC have been conducted. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Loehman, RE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-5221-1 J9 NATO ASI 3 HIGH TECH PY 1998 VL 58 BP 281 EP 293 PG 13 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BM15W UT WOS:000077846500024 ER PT S AU McArthur, JV AF McArthur, JV BE Williams, WD Sladeckova, A TI Physiologic and genetic determinants of lotic bacterial distribution and abundance SO INTERNATIONAL ASSOCIATION OF THEORETICAL AND APPLIED LIMNOLOGY, VOL 26, PT 3 SE INTERNATIONAL ASSOCIATION OF THEORETICAL AND APPLIED LIMNOLOGY - PROCEEDINGS LA English DT Proceedings Paper CT 26th Congress of the International-Association-of-Theoretical-and-Applied-Limnology CY 1995 CL SAO PAULO, BRAZIL SP Int Assoc Theoret & Appl Limnol C1 Savannah River Ecol Lab, Aiken, SC 29802 USA. RP McArthur, JV (reprint author), Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU E SCHWEIZERBART'SCHE VERLAGSBUCHHANDLUNG PI STUTTGART PA JOHANNESTRASSE 3, W-7000 STUTTGART, GERMANY SN 0368-0770 BN 3-510-54047-6 J9 INT VER THEOR ANGEW PY 1998 VL 26 BP 1080 EP 1082 PN 3 PG 3 WC Limnology SC Marine & Freshwater Biology GA BL26L UT WOS:000074937000042 ER PT J AU Boopathy, R Manning, J Kulpa, CF AF Boopathy, R Manning, J Kulpa, CF TI Biotransformation of explosives by anaerobic consortia in liquid culture and in soil slurry SO INTERNATIONAL BIODETERIORATION & BIODEGRADATION LA English DT Article DE explosives; biotransmission; remediation; TNT; soil slurry ID SP B-STRAIN; MICROBIAL TRANSFORMATION; 2,4,6-TRINITROTOLUENE TNT; NITROAROMATIC COMPOUNDS; METHANOGENIC BACTERIA; CONTAMINATED SOILS; BIOREMEDIATION; DEGRADATION; METABOLISM; PRODUCTS AB A laboratory study was conducted to study the feasibility of removing explosives in contaminated soil under anaerobic conditions. Anaerobic enrichment cultures were prepared from soil samples under various electron-accepting conditions, namely, sulfate-reducing, methanogenic, and nitrate-reducing conditions. The sulfate-reducing condition was very effective in removing all of the explosive compounds from the soil. The sulfate-reducing consortium removed 100% of 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitrobenzene (TNB) within 10-15 days of incubation and removed 75 to 95% of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetraazocine (HMX), within 21 days of incubation. The consortium used explosive compounds as the nitrogen source, however, it did not use these compounds as the sole carbon source. The various metabolites obtained from TNT metabolism were 4-amino-2,6-dinitrotoluene (4-A-2,6-DNT), 2,4-diamino-6-nitrotoluene (2,4-D-6-NT), and 2-methyl pentanoic acid. This sulfate-reducing consortium was further studied for its usefulness in removing TNT at the contaminated site. The results showed that the consortium can remove TNT under 5% and 10% soil slurry conditions. This laboratory study demonstrated that under anaerobic conditions, sulfate-reducing bacteria can be useful in the bioremediation of contaminated soil with TNT and other explosives. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. Univ Notre Dame, Dept Biol Sci, Notre Dame, IN 46556 USA. RP Boopathy, R (reprint author), Argonne Natl Lab, Div Environm Res, Bldg 203, Argonne, IL 60439 USA. NR 27 TC 21 Z9 21 U1 1 U2 7 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0964-8305 J9 INT BIODETER BIODEGR JI Int. Biodeterior. Biodegrad. PY 1998 VL 41 IS 1 BP 67 EP 74 DI 10.1016/S0964-8305(98)80009-7 PG 8 WC Biotechnology & Applied Microbiology; Environmental Sciences SC Biotechnology & Applied Microbiology; Environmental Sciences & Ecology GA ZT843 UT WOS:000074133400008 ER PT S AU Keiser, JR Taljat, B Wang, XL Swindeman, RW Meyers, LE Maziasz, PJ Thomas, RL Singbeil, DL Prescott, R Gorog, JP Singh, PM AF Keiser, JR Taljat, B Wang, XL Swindeman, RW Meyers, LE Maziasz, PJ Thomas, RL Singbeil, DL Prescott, R Gorog, JP Singh, PM GP TAPPI TI Overview of the DOE studies of recovery boiler floor tube cracking SO INTERNATIONAL CHEMICAL RECOVERY CONFERENCE, VOLS 1-3 SE TAPPI PROCEEDINGS LA English DT Proceedings Paper CT International Chemical Recovery Conference CY JUN 01-04, 1998 CL TAMPA, FL SP TAPPI, Tech Sect Canadian Pulp & Paper Assoc AB Cracking of the stainless steel layer of coextruded 304L/SA210 recovery boiler floor tubes has been observed in an increasing number of black liquor recovery boilers. Because failure of such tubes is a serious safety concern as well as an economic issue, this project was initiated with the objective of identifying alternate materials or process changes that would prevent tube cracking. Tensile stresses are essential for the most likely failure mechanisms, i.e., fatigue or stress corrosion cracking, therefore stresses were measured at room temperature and modeling was used to predict stresses under operating conditions. Laboratory studies have identified conditions under which composite tubes crack due to thermal fatigue and stress corrosion. Floor tube temperature measurements have defined the magnitude and frequency of temperature fluctuations experienced by such tubes, and smelt corrosion studies have measured the degradation rate when molten smelt comes in contact with tubes. Based on these observations, certain materials appear more likely to resist cracking and certain process changes should help avoid conditions that cause composite tube cracking. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Keiser, JR (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Wang, Xun-Li/C-9636-2010; OI Wang, Xun-Li/0000-0003-4060-8777; Maziasz, Philip/0000-0001-8207-334X NR 0 TC 0 Z9 0 U1 0 U2 0 PU TAPPI PRESS PI ATLANTA PA TECHNOLOGY PARK, PO BOX 105113, ATLANTA, GA 30348 USA SN 1047-3033 BN 0-89852-716-3 J9 P TECH AS P PY 1998 BP 71 EP 86 PG 16 WC Chemistry, Applied; Engineering, Chemical; Materials Science, Paper & Wood SC Chemistry; Engineering; Materials Science GA BL12E UT WOS:000074364900007 ER PT B AU Eisenhawer, SW Bott, TF Helm, TM Boerigter, ST AF Eisenhawer, SW Bott, TF Helm, TM Boerigter, ST GP AICHE AICHE AICHE TI System reliability assessment with an approximate reasoning model SO INTERNATIONAL CONFERENCE AND WORKSHOP ON RELIABILITY AND RISK MANAGEMENT LA English DT Proceedings Paper CT International Conference and Workshop on Reliability and Risk Management CY SEP 15-18, 1998 CL SAN ANTONIO RIVERWALK, TX SP Amer Inst Chem Engineers Ctr Chem Process Safety, ASME Int, US EPA, Hlth & Safety Execut, European Federat Chem Engn (Working Party Loss Prevent, European Process Safety Ctr AB The projected service life of weapons in the United States nuclear stockpile will exceed the original design life of their critical components. Interim metrics are needed to describe weapon states for use in simulation models of the nuclear weapons complex. We present an approach to this problem based upon the theory of approximate reasoning (AR) that allows meaningful assessments to be made in an environment where reliability models are incomplete. AR models are designed to emulate the inference process used by subject matter experts. The emulation is based upon a formal logic structure that relates evidence about components. This evidence is translated using natural language expressions into linguistic variables that describe membership in fuzzy sets. We introduce a metric that measures the "acceptability" of a weapon to nuclear deterrence planners. Implication rule bases are used to draw a series of forward chaining inferences about the acceptability of components, subsystems and individual weapons. We describe each component in the AR model in some detail and illustrate its behavior with a small example. The integration of the acceptability metric into a prototype model to simulate-the weapons complex is also described. C1 Univ Calif Los Alamos Natl Lab, Technol & Safety Assessment Div, Los Alamos, NM 87544 USA. RP Eisenhawer, SW (reprint author), Univ Calif Los Alamos Natl Lab, Technol & Safety Assessment Div, POB 1663, Los Alamos, NM 87544 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-8169-0768-4 PY 1998 BP 521 EP 543 PG 23 WC Engineering, Multidisciplinary; Engineering, Environmental; Engineering, Chemical SC Engineering GA BM59Q UT WOS:000079197300035 ER PT S AU Hyde, JM AF Hyde, JM GP INSTITUT MECH ENGINEERS INSTITUT MECH ENGINEERS TI Overview of US Department of energy technology development programme for decommissioning of nuclear facilities SO INTERNATIONAL CONFERENCE ON NUCLEAR DECOMMISSIONING '98 SE IMECHE CONFERENCE TRANSACTIONS LA English DT Proceedings Paper CT International Conference on Nuclear Decommissioning 98 CY DEC 02-03, 1998 CL LONDON, ENGLAND SP Inst Mech Engn, Nucl Energy Comm, British Nucl Energy Soc AB The US Department of Energy(DOE) has many nuclear facilities requiring decontamination and decommissioning including research and production reactors, hot cells, uranium and plutonium processing buildings, fuel reprocessing canyons, gaseous diffusion and gas centrifuge uranium enrichment plants, weapons production facilities, research laboratories, and waste processing facilities. The Office of Science and Technology initiated the concept of using Large Scale Technology Demonstration Projects to test innovative technologies as part of the ongoing decommissioning project. The objective is to collect cost and performance data for the innovative technologies and compare these to commercially available baseline technologies. C1 US DOE, Washington, DC USA. RP Hyde, JM (reprint author), US DOE, Washington, DC USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI WESTMINISTER PA 1 BIRDCAGE WALK, WESTMINISTER SW1H 9JJ, ENGLAND SN 1356-1448 BN 1-86058-151-X J9 IMECHE CONF TRANS PY 1998 VL 1998 IS 12 BP 83 EP 92 PG 10 WC Engineering, Mechanical; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BM24B UT WOS:000078134100008 ER PT S AU Hamilton, MA Rogers, RD Nelson, LO Holmes, RG Milner, TN AF Hamilton, MA Rogers, RD Nelson, LO Holmes, RG Milner, TN GP INSTITUT MECH ENGINEERS INSTITUT MECH ENGINEERS TI Biodecontamination: cost-benefit analysis of a novel approach for decontamination of massive concrete structures SO INTERNATIONAL CONFERENCE ON NUCLEAR DECOMMISSIONING '98 SE IMECHE CONFERENCE TRANSACTIONS LA English DT Proceedings Paper CT International Conference on Nuclear Decommissioning 98 CY DEC 02-03, 1998 CL LONDON, ENGLAND SP Inst Mech Engn, Nucl Energy Comm, British Nucl Energy Soc ID CORROSION AB A major liability facing the owners and operators of nuclear facilities worldwide is the decontamination and decommissioning of contaminated massive concrete structures. A biodecontamination technology which harnesses the action of naturally occurring bacteria is currently under joint development by BNFL and the INEEL. This emerging technology was judged to exhibit advantages in cost, worker health and safety risk reduction, and programmatic effectiveness. The process takes approximately six months to one year to remove the contaminated surface and can advantageously be applied during the Care and Maintenance phase of a D&D program. A detailed assessment of the biodecontamination process in relation to the next best and base technologies was performed. The findings of this study which recommended a large scale technology demonstration will be presented. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. RP Hamilton, MA (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI WESTMINISTER PA 1 BIRDCAGE WALK, WESTMINISTER SW1H 9JJ, ENGLAND SN 1356-1448 BN 1-86058-151-X J9 IMECHE CONF TRANS PY 1998 VL 1998 IS 12 BP 123 EP 130 PG 8 WC Engineering, Mechanical; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BM24B UT WOS:000078134100012 ER PT B AU Lubeck, OM Luo, Y Wasserman, H Bassetti, F AF Lubeck, OM Luo, Y Wasserman, H Bassetti, F BE Arabnia, HR TI An empirical hierarchical memory model based on hardware performance counters SO INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED PROCESSING TECHNIQUES AND APPLICATIONS, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA 98) CY JUL 13-16, 1998 CL LAS VEGAS, NV SP Comp Sci Res, Educ & Applicat Tech, Natl Partnership Adv Computat Infrastruct, US DOE, Natl Supercomp Ctr Energy & Environm, N Amer Transputer Users Grp, Comp Vis Res & Applicat Tech, High Performance Comp Users Grp DE performance evaluation; cache; memory subsystem; computer architecture; and microprocessor AB In this paper, we characterize application performance with a "memory-centric" view. Using a simple strategy and performance data measured by on-chip hardware performance counters, we model the performance of a simple memory hierarchy and infer the contribution of each level in the memory system to an application's overall cycles per instruction (cpi). We account for the overlap of processor execution with memory accesses - a key parameter not directly measurable on most systems. We infer the separate contributions of three major architecture features in the memory subsystem of the Origin 2000: cache size, outstanding loads-under-miss, and memory latency. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Lubeck, OM (reprint author), Univ Calif Los Alamos Natl Lab, Mail Stop B256, Los Alamos, NM 87544 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU C S R E A PRESS PI ATHENS PA 115 AVALON DR, ATHENS, GA 30606 USA BN 1-892512-08-4 PY 1998 BP 386 EP 393 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BR81K UT WOS:000167625200052 ER PT B AU Driessen, B Womble, D Sadegh, N AF Driessen, B Womble, D Sadegh, N BE Arabnia, HR TI O(log(Number of time steps)) implicit integration of differential equations on massively parallel computers SO INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED PROCESSING TECHNIQUES AND APPLICATIONS, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA 98) CY JUL 13-16, 1998 CL LAS VEGAS, NV SP Comp Sci Res, Educ & Applicat Tech, Natl Partnership Adv Computat Infrastruct, US DOE, Natl Supercomp Ctr Energy & Environm, N Amer Transputer Users Grp, Comp Vis Res & Applicat Tech, High Performance Comp Users Grp DE numerical integration; Runge Kutta; O(log(N)); parallel; Newton Rhaphson; Newton's method AB This work presents a method of performing implicit numerical integration of differential equations in O(log(N)) time, where N is the number of rime steps, using O(N) and O(N/log(N)) processors of a massively parallel computer. To our knowledge, such parallelization of differential equation integration has not been presented and demonstrated before. The method is a Newton Rhaphson algorithm with a line search. The calculation of the Newton Rhaphson search direction and the line search are parallelized. A numerical example an the Intel Paragon at Sandia National Laboratories clearly demonstrates the O(log(N)) time complexity of the algorithm. C1 Sandia Natl Labs, Struct Dynam Dept, Albuquerque, NM 87185 USA. RP Driessen, B (reprint author), Sandia Natl Labs, Struct Dynam Dept, POB 5800, Albuquerque, NM 87185 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU C S R E A PRESS PI ATHENS PA 115 AVALON DR, ATHENS, GA 30606 USA BN 1-892512-08-4 PY 1998 BP 1559 EP 1566 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BR81K UT WOS:000167625200209 ER PT B AU Wyckoff, P Armstrong, R AF Wyckoff, P Armstrong, R BE Arabnia, HR TI Smooth particle hydrodynamics on ATM-connected distributed PC clusters SO INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED PROCESSING TECHNIQUES AND APPLICATIONS, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA 98) CY JUL 13-16, 1998 CL LAS VEGAS, NV SP Comp Sci Res, Educ & Applicat Tech, Natl Partnership Adv Computat Infrastruct, US DOE, Natl Supercomp Ctr Energy & Environm, N Amer Transputer Users Grp, Comp Vis Res & Applicat Tech, High Performance Comp Users Grp DE ATM; cluster; SPH AB The simulation of a fluid flow wing smooth particle hydrodynamics is performed on clusters of inexpensive personal computers. These clusters achieve connectivity in the wide area using ATM across links of a variety of capacities. Utilization of a full OC12 (622 Mb/s) of bandwidth is obtained using commodity OC3 network interface cards by striping the application data across multiple nodes in parallel. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Wyckoff, P (reprint author), Sandia Natl Labs, MS 9011,POB 969, Livermore, CA 94551 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU C S R E A PRESS PI ATHENS PA 115 AVALON DR, ATHENS, GA 30606 USA BN 1-892512-08-4 PY 1998 BP 1599 EP 1605 PG 7 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BR81K UT WOS:000167625200214 ER PT B AU Yuan, V AF Yuan, V BE Wang, F TI Neutron resonances in the compound nucleus: Parity nonconservation to dynamic temperature measurements SO INTERNATIONAL CONFERENCE ON PHYSICS SINCE PARITY SYMMETRY BREAKING: IN MEMORY OF PROFESSOR C. S. WU LA English DT Proceedings Paper CT International Conference on Physics Since Parity Symmetry Breaking - In Memory of Professor C S Wu CY AUG 16-18, 1997 CL NANJING, PEOPLES R CHINA SP Chinese Phys Soc, Amer Phys Soc, Nanjing Univ, Southeast Univ, State Sci & Technol Commiss China, State Educ Commiss china, Chinese Acad Sci, Natl Nat Sci Fdn China, Chinese Assoc Sci & Technol, Govt Jiangsu Province, Elite Ind Holdings Ltd, Mandarin Garden Hotel AB Experiments using epithermal neutrons that interact to form compound-nuclear resonances serve a wide range of scientific applications. Changes in transmission which are correlated to polarization reversal in incident neutrons have been used to study parity nonconservation in the compound nucleus for a wide range of targets. The ensemble of measured parity asymmetries provides statistical information for the extraction of the rms parity-violating mean-square matrix element as a function of mass. Parity nonconservation in neutron resonances can also be used to determine the polarization of neutron beams. Finally, the motion of target atoms results in an observed temperature-dependent Doppler broadening of resonance line widths. This broadening can be used to determine temperatures on a fast time scale of one microsecond or less. C1 Univ Calif Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Yuan, V (reprint author), Univ Calif Los Alamos Natl Lab, Div Phys, MS H803, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3475-9 PY 1998 BP 19 EP 30 PG 12 WC Physics, Multidisciplinary; Physics, Nuclear; Physics, Particles & Fields SC Physics GA BM22J UT WOS:000078053400002 ER PT B AU Tsai, YS AF Tsai, YS BE Wang, F TI CP violation in tau ->nu(tau)+3 pi SO INTERNATIONAL CONFERENCE ON PHYSICS SINCE PARITY SYMMETRY BREAKING: IN MEMORY OF PROFESSOR C. S. WU LA English DT Proceedings Paper CT International Conference on Physics Since Parity Symmetry Breaking - In Memory of Professor C S Wu CY AUG 16-18, 1997 CL NANJING, PEOPLES R CHINA SP Chinese Phys Soc, Amer Phys Soc, Nanjing Univ, Southeast Univ, State Sci & Technol Commiss China, State Educ Commiss china, Chinese Acad Sci, Natl Nat Sci Fdn China, Chinese Assoc Sci & Technol, Govt Jiangsu Province, Elite Ind Holdings Ltd, Mandarin Garden Hotel AB We discuss the ways to find CP violation in the decay of tau(+/-) --> nu(tau) + 3 pi from unpolarized as well as polarized tau(+/-). C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Tsai, YS (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3475-9 PY 1998 BP 74 EP 84 PG 11 WC Physics, Multidisciplinary; Physics, Nuclear; Physics, Particles & Fields SC Physics GA BM22J UT WOS:000078053400006 ER PT B AU Appel, JA AF Appel, JA BE Wang, F TI From symmetry violation to dynamics: The charm window SO INTERNATIONAL CONFERENCE ON PHYSICS SINCE PARITY SYMMETRY BREAKING: IN MEMORY OF PROFESSOR C. S. WU LA English DT Proceedings Paper CT International Conference on Physics Since Parity Symmetry Breaking - In Memory of Professor C S Wu CY AUG 16-18, 1997 CL NANJING, PEOPLES R CHINA SP Chinese Phys Soc, Amer Phys Soc, Nanjing Univ, Southeast Univ, State Sci & Technol Commiss China, State Educ Commiss china, Chinese Acad Sci, Natl Nat Sci Fdn China, Chinese Assoc Sci & Technol, Govt Jiangsu Province, Elite Ind Holdings Ltd, Mandarin Garden Hotel AB C.S. Wu observed parity violation in the low energy process of nuclear decay. She was the first to observe this symmetry violation at any energy. Yet, her work taught us about the form and strengths of the couplings of the massive weak boson. Today, we use the same approach. We look for very much higher mass-scale interactions through symmetry violations in the decays of charm quark systems. These charm decays provide a unique window to new physics. C1 Fermilab, Batavia, IL 60510 USA. RP Appel, JA (reprint author), Fermilab, POB 500, Batavia, IL 60510 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3475-9 PY 1998 BP 343 EP 357 PG 15 WC Physics, Multidisciplinary; Physics, Nuclear; Physics, Particles & Fields SC Physics GA BM22J UT WOS:000078053400032 ER PT B AU Strobel, GL AF Strobel, GL BE Wang, F TI Proton properties in a relativistic three quark model SO INTERNATIONAL CONFERENCE ON PHYSICS SINCE PARITY SYMMETRY BREAKING: IN MEMORY OF PROFESSOR C. S. WU LA English DT Proceedings Paper CT International Conference on Physics Since Parity Symmetry Breaking - In Memory of Professor C S Wu CY AUG 16-18, 1997 CL NANJING, PEOPLES R CHINA SP Chinese Phys Soc, Amer Phys Soc, Nanjing Univ, Southeast Univ, State Sci & Technol Commiss China, State Educ Commiss china, Chinese Acad Sci, Natl Nat Sci Fdn China, Chinese Assoc Sci & Technol, Govt Jiangsu Province, Elite Ind Holdings Ltd, Mandarin Garden Hotel AB The proton is modeled as three equal mass quarks of small current quark mass. The three body Dirac equation is solved with spin independent central diagonal linear confining potentials with an attractive coulombic term in hypercentral approximation. Hyperspherical coordinates are used and the bound state is found analytically for the (1/2(+))(3) configuration of positive parity. The configuration is coupled to reproduce the spin of the proton. The usual quark charges of 2/3, 2/3, and -1/3 are the only charges assumed present in the model. The proton rest energy, rms charge radius, magnetic moment,and Axial charge constant are reproduced with this model. The quark helicity contribution to the proton is also reproduced. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Strobel, GL (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3475-9 PY 1998 BP 462 EP 466 PG 5 WC Physics, Multidisciplinary; Physics, Nuclear; Physics, Particles & Fields SC Physics GA BM22J UT WOS:000078053400045 ER PT B AU Burgess, W Craddock, WC Kurtcuoglu, K Quack, H AF Burgess, W Craddock, WC Kurtcuoglu, K Quack, H BE DewHughes, D Scurlock, RG Watson, JHP TI Reconfiguration of a B & W/SSC/Linde liquefier to meet SLAC BaBar Detector Magnet requirements SO INTERNATIONAL CRYOGENIC ENGINEERING CONFERENCE 1998 LA English DT Proceedings Paper CT 17th International Cryogenic Engineering Conference CY JUL 14-17, 1998 CL BOURNEMOUTH, ENGLAND SP Air Prod Ltd, A S Sci Ltd, BOC Ltd, BOC Proc Plants, British Cryoengn Soc, Elsevier Sci Ltd, HPC Engn plc, Hyrolec Tech Serv Ltd, Int Cryogen Engn Comm, Int Inst Refrigerat, Oxford Instruments Ltd, Linde Cryogen Ltd, Merck Ltd, Univ Southampton, Weka AG AB A partly finished helium refrigeration and liquefaction plant, originally designed and intended for use on the SSC quadrupole magnet testing program, has been successfully adapted for use with the SLAC/BaBar Detector Magnet. Via judicious reconfiguration, the plant's intended role was considerably modified to satisfy SLAC's projected physics program. C1 Stanford Linear Accelerator Ctr, EFD Cryogen Grp, Menlo Park, CA 94025 USA. RP Burgess, W (reprint author), Stanford Linear Accelerator Ctr, EFD Cryogen Grp, Menlo Park, CA 94025 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND BN 0-7503-0597-5 PY 1998 BP 149 EP 156 PG 8 WC Thermodynamics; Engineering, Mechanical; Mechanics; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Mechanics; Physics GA BM16L UT WOS:000077869200029 ER PT B AU Jia, LX Passell, L Rorer, DC AF Jia, LX Passell, L Rorer, DC BE DewHughes, D Scurlock, RG Watson, JHP TI A proposed upgrade of the liquid hydrogen moderator at Brookhaven's High Flux Beam Reactor SO INTERNATIONAL CRYOGENIC ENGINEERING CONFERENCE 1998 LA English DT Proceedings Paper CT 17th International Cryogenic Engineering Conference CY JUL 14-17, 1998 CL BOURNEMOUTH, ENGLAND SP Air Prod Ltd, A S Sci Ltd, BOC Ltd, BOC Proc Plants, British Cryoengn Soc, Elsevier Sci Ltd, HPC Engn plc, Hyrolec Tech Serv Ltd, Int Cryogen Engn Comm, Int Inst Refrigerat, Oxford Instruments Ltd, Linde Cryogen Ltd, Merck Ltd, Univ Southampton, Weka AG AB A new liquid hydrogen moderator proposed for Brookhaven's High Flux Beam Reactor is described and comparisons are made to the existing moderator and a state-of-the-art moderator recently installed at the National Institute of Standards and Technology's research reactor. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Jia, LX (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND BN 0-7503-0597-5 PY 1998 BP 245 EP 249 PG 5 WC Thermodynamics; Engineering, Mechanical; Mechanics; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Mechanics; Physics GA BM16L UT WOS:000077869200048 ER PT B AU Morgan, GH AF Morgan, GH BE DewHughes, D Scurlock, RG Watson, JHP TI End design of a helically-wound magnet for RHIC SO INTERNATIONAL CRYOGENIC ENGINEERING CONFERENCE 1998 LA English DT Proceedings Paper CT 17th International Cryogenic Engineering Conference CY JUL 14-17, 1998 CL BOURNEMOUTH, ENGLAND SP Air Prod Ltd, A S Sci Ltd, BOC Ltd, BOC Proc Plants, British Cryoengn Soc, Elsevier Sci Ltd, HPC Engn plc, Hyrolec Tech Serv Ltd, Int Cryogen Engn Comm, Int Inst Refrigerat, Oxford Instruments Ltd, Linde Cryogen Ltd, Merck Ltd, Univ Southampton, Weka AG AB The coils of helically-wound, low current magnets for RHIC are placed in slots machined into an aluminum cylinder. The design of these slots in the magnet ends is described, and the method of computation of the central and end field harmonics is outlined. Calculations are compared with measurements made on the prototype. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Morgan, GH (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND BN 0-7503-0597-5 PY 1998 BP 431 EP 434 PG 4 WC Thermodynamics; Engineering, Mechanical; Mechanics; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Mechanics; Physics GA BM16L UT WOS:000077869200093 ER PT B AU Byrns, R Huang, Y Kerby, J Lebrun, P Morrison, L Nicol, T Peterson, T Trant, R van Weelderen, R Zbasnik, J AF Byrns, R Huang, Y Kerby, J Lebrun, P Morrison, L Nicol, T Peterson, T Trant, R van Weelderen, R Zbasnik, J BE DewHughes, D Scurlock, RG Watson, JHP TI The cryogenics of the LHC interaction region final focus superconducting magnets SO INTERNATIONAL CRYOGENIC ENGINEERING CONFERENCE 1998 LA English DT Proceedings Paper CT 17th International Cryogenic Engineering Conference CY JUL 14-17, 1998 CL BOURNEMOUTH, ENGLAND SP Air Prod Ltd, A S Sci Ltd, BOC Ltd, BOC Proc Plants, British Cryoengn Soc, Elsevier Sci Ltd, HPC Engn plc, Hyrolec Tech Serv Ltd, Int Cryogen Engn Comm, Int Inst Refrigerat, Oxford Instruments Ltd, Linde Cryogen Ltd, Merck Ltd, Univ Southampton, Weka AG AB The LHC interaction region final focus magnets will include four superconducting quadrupoles cooled with pressurized, static superfluid helium at 1.9 K. The heat absorbed in pressurized He II, which may be more than 10 Wads per meter due to dynamic heating from the particle beam halo, will be transported to saturated He II at 1.8 K and removed by the 16 mbar vapor. This paper discusses the conceptual design for the cryogenics of the interaction region final focus superconducting magnets and the integration of this magnet system into the overall LHC cryogenic system. C1 Fermilab, Batavia, IL 60510 USA. RP Byrns, R (reprint author), Fermilab, Batavia, IL 60510 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND BN 0-7503-0597-5 PY 1998 BP 743 EP 746 PG 4 WC Thermodynamics; Engineering, Mechanical; Mechanics; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Mechanics; Physics GA BM16L UT WOS:000077869200169 ER PT B AU Theiss, SD Carey, PG Smith, PM Wickboldt, P Sigmon, TW Tung, YJ King, TJ AF Theiss, SD Carey, PG Smith, PM Wickboldt, P Sigmon, TW Tung, YJ King, TJ GP IEEE IEEE TI PolySilicon thin film transistors fabricated at 100 degrees C on a flexible plastic substrate SO INTERNATIONAL ELECTRON DEVICES MEETING 1998 - TECHNICAL DIGEST LA English DT Proceedings Paper CT International Electron Devices Meeting (IEDM) CY DEC 06-09, 1998 CL SAN FRANCISCO, CA SP Electron Devices Soc IEEE ID GLASS; TFTS AB We present device results from polysilicon thin film transistors (TFTs) fabricated at a maximum temperature of 100 degrees C on plastic (PET) substrates. A XeCl excimer laser has been used both to crystallize sputtered a-Si and to heavily dope the TFT source/drain regions. Using a PECVD SiO2 layer for the gate dielectric, and a post-fabrication anneal at 150 degrees C, we have succeeded in fabricating TFTs with I-ON/I-OFF ratios >5x10(5) and electron mobilities >60 cm(2)/V-s on polyester substrates. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Theiss, SD (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-271, Livermore, CA 94551 USA. NR 9 TC 30 Z9 30 U1 2 U2 5 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4774-9 PY 1998 BP 257 EP 260 DI 10.1109/IEDM.1998.746349 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BM38T UT WOS:000078581800059 ER PT B AU Caturla, MJ Theiss, SK Lenosky, TJ de la Rubia, TD AF Caturla, MJ Theiss, SK Lenosky, TJ de la Rubia, TD GP IEEE IEEE TI Defect and dopant diffusion in ion implanted silicon: An atomic scale simulation approach SO INTERNATIONAL ELECTRON DEVICES MEETING 1998 - TECHNICAL DIGEST LA English DT Proceedings Paper CT International Electron Devices Meeting (IEDM) CY DEC 06-09, 1998 CL SAN FRANCISCO, CA SP Electron Devices Soc IEEE ID DAMAGE; ENERGY; SI AB We present an atomistic approach to the development of predictive process simulation tools. First principles methods are used to construct a database of defect and dopant energetics. This is used as input for kinetic Monte Carlo simulations of ion implantation and dopant diffusion under a wide variety of technologically relevant conditions. Our simulations are in excellent agreement with annealing experiments on 20-80 keV B implants into Si, and with those on 50 keV Si implants into complex B-doped structures. Our calculations produce novel predictions of the time evolution of the electrically active B fraction during annealing. C1 Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. RP Caturla, MJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. NR 16 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4774-9 PY 1998 BP 489 EP 492 DI 10.1109/IEDM.1998.746404 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BM38T UT WOS:000078581800113 ER PT B AU Ibrahim, MA Nimlos, M Filley, J Blake, D Watt, A Wolfrum, E Muralidharan, S AF Ibrahim, MA Nimlos, M Filley, J Blake, D Watt, A Wolfrum, E Muralidharan, S GP TAPPI TI Photoactive ion exchange resins SO INTERNATIONAL ENVIRONMENTAL CONFERENCE & EXHIBIT, BOOKS 1-3 LA English DT Proceedings Paper CT 1998 TAPPI International Environmental Conference and Exhibit CY APR 05-08, 1998 CL VANCOUVER TRADE CONVENT CTR, VANCOUVER, CANADA SP TAPPI HO VANCOUVER TRADE CONVENT CTR AB As the forest product industry move towards closed cycle pulping processes, the ability to remove non-process elements from water streams becomes more critical. Dissolved species such as calcium, magnesium and transition metals such as manganese, iron and anions such as oxalates can build up in process waters and lead to scale formation and catalytic decomposition of bleaching agents. Ion exchange and precipitation using sequestering agents are currently used as technologies to help with this problem. We are developing a new class of photoactive ion exchange resins that can be regenerated with less energy and solvents than conventional resins and will be effective for recycling, water reduction and pollution prevention. As a proof of concept, we have synthesized several photoactive dyes based on spiropyran and tested for its metal binding ability. These dyes have also been anchored onto solid support and its metal and anion binding ability were studied. Initial results were encouraging and could lead to product development in future. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ibrahim, MA (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU TAPPI PRESS PI ATLANTA PA TECHNOLOGY PARK, PO BOX 105113, ATLANTA, GA 30348 USA BN 0-89852-713-9 PY 1998 BP 215 EP 216 PG 2 WC Engineering, Chemical; Materials Science, Paper & Wood SC Engineering; Materials Science GA BK86S UT WOS:000073706800022 ER PT B AU Smith, M AF Smith, M GP TAPPI TI Overview of industries of the future and the forest products industry's Agenda 2020 SO INTERNATIONAL ENVIRONMENTAL CONFERENCE & EXHIBIT, BOOKS 1-3 LA English DT Proceedings Paper CT 1998 TAPPI International Environmental Conference and Exhibit CY APR 05-08, 1998 CL VANCOUVER TRADE CONVENT CTR, VANCOUVER, CANADA SP TAPPI HO VANCOUVER TRADE CONVENT CTR AB The Department of Energy's Office of Industrial Technologies (OIT), began their Industries of the Future Program (IOF) five years ago. The goal of this program is to target energy and material intensive U.S. industries to aid in improving energy and resource efficiency and reducing wastes through research and development. The industries that OIT is currently working with are Forest Products, Steel, Metal Casting, Aluminum, Glass, Chemicals, and Petroleum Refining. These seven industries use 80 percent of the energy in the manufacturing sector and produce more than 90 percent of manufacturing wastes. In addition to large energy use and wastes produced, these seven industries have the highest energy expenditures and pollution abatement costs and extremely low expenditures on research and development as a percent of sales. The IOF provides a strategic vision that identifies long term market and technology needs, enables an entire industry to address its major challenges and opportunities, and aligns limited government and industry resources with high priority research needs. The forest products industry prepared their vision document, Agenda 2020, in November 1994. Agenda 2020 targets six strategic areas: sustainable forest management, environmental performance, energy performance, improved capital effectiveness, recycling, and sensors and controls. In conjunction with industry, OIT has begun funding pre-competitive, research and development projects in support of Agenda 2020's six strategic areas. To date, OIT has funded 21 new projects in fiscal 1996 and 28 new projects in fiscal 1997. OIT is currently in the selection process for projects that will begin in fiscal 1999. C1 US DOE, Off Ind Technol, Washington, DC 20585 USA. RP Smith, M (reprint author), US DOE, Off Ind Technol, Washington, DC 20585 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU TAPPI PRESS PI ATLANTA PA TECHNOLOGY PARK, PO BOX 105113, ATLANTA, GA 30348 USA BN 0-89852-713-9 PY 1998 BP 1117 EP 1119 PG 3 WC Engineering, Chemical; Materials Science, Paper & Wood SC Engineering; Materials Science GA BK86S UT WOS:000073706800120 ER PT B AU Watt, AS AF Watt, AS GP TAPPI TI An investigation into the use of low temperature catalytic oxidation for the control of volatile organic compounds released from forest product industry operations SO INTERNATIONAL ENVIRONMENTAL CONFERENCE & EXHIBIT, BOOKS 1-3 LA English DT Proceedings Paper CT 1998 TAPPI International Environmental Conference and Exhibit CY APR 05-08, 1998 CL VANCOUVER TRADE CONVENT CTR, VANCOUVER, CANADA SP TAPPI HO VANCOUVER TRADE CONVENT CTR AB The release of volatile organic air emissions from pulping and papermaking operations is coming under increased scrutiny with the promulgation of the Cluster Rules by the U.S. Environmental Protection Agency on November 14, 1997. Catalytic oxidation is a technology for controlling this type of emission in other industries. This research project investigates a variety of catalysts to determine what conditions are necessary to control the emissions of volatile organic compounds (VOCs) from pulp and paper operations, as well as from lumber drying kilns. A platinized alumina catalyst can reduce methanol concentrations by 99% at a temperature of 150 degrees C. Destruction of methyl sulfide and methanol has been achieved using a cobalt molybdate catalyst at a temperature of 250 degrees C. While field tests using actual mill emissions to determine the effect of other constituents in the air streams will be critical to ensure success, these results suggest that VOC emissions may be significantly reduced at conditions much more moderate that those required by thermal incineration. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Watt, AS (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 0 TC 0 Z9 0 U1 1 U2 3 PU TAPPI PRESS PI ATLANTA PA TECHNOLOGY PARK, PO BOX 105113, ATLANTA, GA 30348 USA BN 0-89852-713-9 PY 1998 BP 1131 EP 1137 PG 7 WC Engineering, Chemical; Materials Science, Paper & Wood SC Engineering; Materials Science GA BK86S UT WOS:000073706800122 ER PT J AU Gresho, PM Chan, ST AF Gresho, PM Chan, ST TI Projection 2 goes turbulent - and fully implicit SO INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS LA English DT Article; Proceedings Paper CT 3rd US/Japan Symposium on Finite Element Methods in Large-Scale Computational Fluid Dynamics CY APR 01-03, 1996 CL UNIV MINNESOTA, ARMY HIGH PERFORMANCE COMP RES CTR, MINNEAPOLIS, MN SP Univ Minnesota, Army High Performance Comp Res Ctr, Dept Aerosp Engn & Mech, Univ Minnesota, Supercomp Inst HO UNIV MINNESOTA, ARMY HIGH PERFORMANCE COMP RES CTR DE projection methods; turbulence models; nonlinear eddy viscosity; FEM ID INCOMPRESSIBLE-FLOW; BLUFF-BODY; AERODYNAMICS; MATRIX; ISSUES AB We describe and demonstrate both our newest projection method (fully implicit) for the incompressible Navier-Stokes equations via the finite element method and our newest turbulence model-a somewhat sophisticated nonlinear (cubic) eddy viscosity model that does not employ wall functions or normal distances to walls - the combination providing a method and a model that is each applicable in arbitrary geometry. We demonstrate both via a flow simulation past an automobile-like body at a Reynolds number of 4.3 million. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Lawrence Livermore Natl Lab, POB 808,L-103, Livermore, CA 94551 USA. NR 27 TC 13 Z9 13 U1 1 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 1061-8562 EI 1029-0257 J9 INT J COMPUT FLUID D JI Int. J. Comput. Fluid Dyn. PY 1998 VL 9 IS 3-4 SI SI BP 249 EP + DI 10.1080/10618569808940857 PG 29 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA ZY527 UT WOS:000074630900007 ER PT J AU VanHorn, RL Hampton, NL Morris, RC AF VanHorn, RL Hampton, NL Morris, RC TI Methodology for conducting screening-level ecological risk assessments for hazardous waste sites. Part I: overview SO INTERNATIONAL JOURNAL OF ENVIRONMENT AND POLLUTION LA English DT Article DE ecological risk assessment; functional groups; Idaho National Engineering and Environmental Laboratory; screening level ERA AB The Idaho National Engineering and Environmental Laboratory (INEEL) is a Department of Energy (DOE) facility. To assess the impact of the sire activities and releases on ecological receptors, the INEEL implemented a phased approach for conducting ecological risk assessments (ERAs). This approach applies an iterative, 'tiered' process, in which conservative preliminary assessments support progressively more refined assessments, The first phase is the screening-level ERA, which is a 'preassessment' performed at the Waste Area Group (WAG) level, This paper will address innovative methods, at the screening level, used to address systematically the complexity of the INEEL site, including adaptations of existing ERA methodologies to accommodate the functional grouping approach. C1 Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Environm Sci & Res Fdn, Idaho Falls, ID 83405 USA. RP VanHorn, RL (reprint author), Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU INDERSCIENCE ENTERPRISES LTD PI GENEVA AEROPORT PA WORLD TRADE CENTER BLDG 110 AVE LOUSIS CASAI CP 306, CH-1215 GENEVA AEROPORT, SWITZERLAND SN 0957-4352 J9 INT J ENVIRON POLLUT JI Int. J. Environ. Pollut. PY 1998 VL 9 IS 1 BP 26 EP 46 PG 21 WC Environmental Sciences SC Environmental Sciences & Ecology GA ZC126 UT WOS:000072542500003 ER PT J AU Hampton, NL Morris, RC VanHorn, RL AF Hampton, NL Morris, RC VanHorn, RL TI Methodology for conducting screening-level ecological risk assessments for hazardous waste sites. Part II: grouping ecological components SO INTERNATIONAL JOURNAL OF ENVIRONMENT AND POLLUTION LA English DT Article DE assessment endpoints; ecological risk assessment; ecological organization; functional group; Idaho National Engineering and Environmental Laboratory AB Screening-level ecological risk assessments are commonly conducted to identify those contaminants and receptors on which to focus future phases or tiers of the ecological risk assessment process. Most screening assessments are performed using a suite of individual species subjected to intensive evaluation of exposure (endpoint species) and selected for their appropriateness for serving as representatives or 'indicators' for all other species. As site complexity and the number of contaminants of concern increase, it becomes more difficult to assure with confidence that the potential for significant effects has been adequately assessed through an appropriate choice of endpoint species. As an alternative, functional groups demonstrating biological similarity and similar potential for contaminant exposure were developed for INEEL screening-level ecological risk assessments using taxonomic, trophic and habitat parameters. Data for individual species within each group are then integrated to address the potential for risk of adverse effects from contaminant exposure for the group as a whole. C1 Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Environm Sci & Res Fdn, Idaho Falls, ID 83405 USA. RP Hampton, NL (reprint author), Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 16 TC 3 Z9 3 U1 0 U2 0 PU INDERSCIENCE ENTERPRISES LTD PI GENEVA AEROPORT PA WORLD TRADE CENTER BLDG 110 AVE LOUSIS CASAI CP 306, CH-1215 GENEVA AEROPORT, SWITZERLAND SN 0957-4352 J9 INT J ENVIRON POLLUT JI Int. J. Environ. Pollut. PY 1998 VL 9 IS 1 BP 47 EP 61 PG 15 WC Environmental Sciences SC Environmental Sciences & Ecology GA ZC126 UT WOS:000072542500004 ER PT J AU Kester, JE VanHorn, RL Hampton, NL AF Kester, JE VanHorn, RL Hampton, NL TI Methodology for conducting screening-level ecological risk assessments for hazardous waste sites. Part III: exposure and effects assessment SO INTERNATIONAL JOURNAL OF ENVIRONMENT AND POLLUTION LA English DT Article DE ecologically based screening levels; ecological risk assessment; effects assessment; exposure assessment; functional groups; receptor of concern; toxicity reference values ID POLYCHLORINATED-BIPHENYLS; CHRONIC TOXICITY; METHYL MERCURY; METHYLMERCURY; MINK; REPRODUCTION; PCBS; BIOACCUMULATION; ACCUMULATION; COMBINATION AB The Idaho National Engineering and Environmental Laboratory (INEEL) has implemented a phased approach to ecological risk assessment (ERA). The first step in this process is a screening-level ERA at each facility. Basic to this approach was the development of ecologically based screening levels (EBSLs), defined as concentrations of chemicals in soil (or other media) that are not expected to produce any adverse effects on selected ecological receptors under chronic exposure conditions (analogous to preliminary remediation goals or soil screening levels). EBSLs are calculated by rearrangement of standard exposure equations to solve for soil concentration when chemical intake rate is set at a developed toxicity reference value (TRV). A TRV is defined as a chronic dose that is likely to be without appreciable risk of deleterious effects, This definition was extended to define TRVs and ultimately EBSLs for the functional groups used in the INEEL screening-level ERAs. C1 Dames & Moore Inc, Denver, CO 80202 USA. Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Kester, JE (reprint author), Dames & Moore Inc, Suite 2500,633 17th St, Denver, CO 80202 USA. NR 50 TC 2 Z9 2 U1 0 U2 1 PU INDERSCIENCE ENTERPRISES LTD PI GENEVA AEROPORT PA WORLD TRADE CENTER BLDG 110 AVE LOUSIS CASAI CP 306, CH-1215 GENEVA AEROPORT, SWITZERLAND SN 0957-4352 J9 INT J ENVIRON POLLUT JI Int. J. Environ. Pollut. PY 1998 VL 9 IS 1 BP 62 EP 89 PG 28 WC Environmental Sciences SC Environmental Sciences & Ecology GA ZC126 UT WOS:000072542500005 ER PT J AU Liu, C Knauss, WG Rosakis, AJ AF Liu, C Knauss, WG Rosakis, AJ TI Loading rates and the dynamic initiation toughness in brittle solids SO INTERNATIONAL JOURNAL OF FRACTURE LA English DT Article DE dynamic fracture; initiation toughness; brittle fracture ID CRACK; FRACTURE; INSTABILITY; EXTENT; FIELD; TIP AB The experimentally determined marked rise of the stress intensity factor required to initiate crack propagation in brittle solids under variably high loading rates, is analyzed. This problem of fracture initiation at the tip of a crack is considered in terms of activating a flaw at some distance away from the tip. By using a semi-infinite crack in an unbounded two-dimensional solid subjected to spatially uniform but temporally varying crack-face pressure, we consider the evolution of stress at the failure initiation site. Fracture initiation is assumed synonymous with attaining a critical stress at the fracture site. The results conform to typical experimental data of dynamic crack initiation in brittle solids. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. CALTECH, Grad Aeronaut Labs, Pasadena, CA 91125 USA. RP Liu, C (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MS-G755, Los Alamos, NM 87545 USA. NR 14 TC 26 Z9 29 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0376-9429 J9 INT J FRACTURE JI Int. J. Fract. PY 1998 VL 90 IS 1-2 BP 103 EP 118 DI 10.1023/A:1007447603177 PG 16 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA 183WV UT WOS:000079577900007 ER PT J AU Liu, C Rosakis, AJ Ellis, RW Stout, MG AF Liu, C Rosakis, AJ Ellis, RW Stout, MG TI A study of the fracture behavior of unidirectional fiber-reinforced composites using Coherent Gradient Sensing (CGS) interferometry SO INTERNATIONAL JOURNAL OF FRACTURE LA English DT Article DE composite fracture; optical method; stress intensity factors; fracture toughness ID MECHANICS APPLICATIONS; FOURIER OPTICS; SENSITIVITY; ACCURACY; SENSOR AB The feasibility of using Coherent Gradient Sensing (CGS) interferometry for studying the fracture behavior of unidirectional fiber-reinforced composites is investigated in this paper. First, the solution for the deformation field surrounding the tip of a crack in an orthotropic material is summarized. Specifically, the most singular term in the asymptotic expansion is explicitly presented. Then, the quantities that relate to the CGS measurements are derived in terms of the spatial position, stress intensity factors, and material constants. Based on these results, synthetic CGS fringe patterns are plotted numerically, and the effects of material anisotropy and crack-tip mixity on the shape of CGS fringe pattern are investigated. in addition, a finite difference interpretation of CGS fringes caused by the finite spacing of the CGS diffraction gratings is taken into account in the simulation. Finally, the initiation fracture toughness and the subsequent resistance curve behavior of a particular unidirectional graphite/epoxy composite are measured using the CGS method. The optically measured stress intensity factors compare successfully to values obtained from the load measurements and the available analytical solutions. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. CALTECH, Grad Aeronaut Labs, Pasadena, CA 91125 USA. RP Liu, C (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MST-8, Los Alamos, NM 87545 USA. NR 20 TC 12 Z9 13 U1 0 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0376-9429 J9 INT J FRACTURE JI Int. J. Fract. PY 1998 VL 90 IS 4 BP 355 EP 382 DI 10.1023/A:1007479709559 PG 28 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA 183WX UT WOS:000079578100005 ER PT J AU Reedy, ED Guess, TR AF Reedy, ED Guess, TR TI Interface corner failure analysis of joint strength: Effect of adherend stiffness SO INTERNATIONAL JOURNAL OF FRACTURE LA English DT Article DE adhesive; bond; corner; interface; joint; strength ID INTENSITY FACTOR PREDICTION; ANISOTROPIC MATERIALS; STRESS SINGULARITY; TENSILE-STRENGTH; FIELDS AB The strength of cylindrical butt joints, fabricated by bonding either aluminum or steel adherends together with an epoxy adhesive, has been determined for a wide range of bond thicknesses. Joint strength varied significantly with bond thickness. The measured strength of joints with steel adherends varied as the inverse cube root of bond thickness, while the strength of joints with aluminum adherends varied as the inverse fourth root of bond thickness. This bond thickness dependence is accurately predicted by an analysis that assumes failure occurs at a critical value of the interface corner stress intensity factor. The difference in the measured joint strength-bond thickness relation for joints with aluminum and steel adherends is a consequence of the difference in the order of the interface corner stress singularity. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Reedy, ED (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 23 TC 10 Z9 10 U1 1 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0376-9429 J9 INT J FRACTURE JI Int. J. Fract. PY 1998 VL 88 IS 4 BP 305 EP 314 PG 10 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA 133MX UT WOS:000076691300001 ER PT J AU Candy, JV AF Candy, JV TI Dynamic surface imaging for the space shuttle experiments SO INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY LA English DT Article AB In this article we discuss various techniques developed to estimate the position and velocity vector of the surface of an object subjected to various forces, both translational and rotational, during an analysis experiment to be performed on the U.S. Space Shuttle. This dynamical information will be used to understand the underlying dynamics of the overall system under investigation and develop an improved design. Here the emphasis is on the measurement sensor and the basic image processing required to achieve the goal of making this measurement. The scheme will be to provide a small cylindrical hole(s) in the mechanism under investigation, illuminate the surface through this "porthole," and obtain a real-time image of the surface on a charged-coupled device (CCD) sensor array. The CCD array data will be compressed and transmitted to the ground tracking station as well as archived for future processing. Also, the design of an optimal tracker capable of providing both two-dimensional position and velocity estimates in real time is discussed. In this case, data synthesized from a dynamic simulation are processed demonstrating its capability and predicted performance. (C) 1998 John Wiley & Sons, Inc. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Candy, JV (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-156, Livermore, CA 94551 USA. NR 10 TC 0 Z9 0 U1 1 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0899-9457 J9 INT J IMAG SYST TECH JI Int. J. Imaging Syst. Technol. PY 1998 VL 9 IS 6 BP 463 EP 474 PG 12 WC Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Engineering; Optics; Imaging Science & Photographic Technology GA 141TR UT WOS:000077160500008 ER PT J AU Godwin, RP Chapyak, EJ AF Godwin, RP Chapyak, EJ TI Apparent target strength in long-rod penetration SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article ID HYDRODYNAMIC THEORY; MODELS; FLOW AB We investigate the apparent enhancement of target strength in the steady-slate Tale model of long-rod penetration. Computing the effective area over which the target behaves as a fluid provides a satisfactory explanation of the measured effective one-dimensional target strength. Expressing the effective target strength as R-t = aY(1), we postulate that a = A(e)/A(p), where Y-t is the nominal strength; A(e) is the effective target fluid cross-sectional area and A(p) the true projectile cross-sectional area. For the case of a rod and projectile of the same material, we use the Tate model together with the Birkhoff jet model to show a approximate to 4 is likely. Simultaneously satisfying Newton's Second Law and the Tate model yields a = 4 for purely fluid behavior, i.e. at high penetrator velocities. By explicitly including strength terms in both Bernoulli's Law and Newton's Second Law, we derive a more general strength multiplier. This multiplier is a Function of the penetrator velocity as well as the density and strength of both the penetrator and target. At the velocity threshold for steady-slate eroding-rod penetration, a = 2 + 2 root 1-Y-p/Y-t, where Y-p is the projectile strength. (C) 1997 Published by Elsevier Science Ltd. C1 Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Grp XNH, Los Alamos, NM 87545 USA. RP Godwin, RP (reprint author), Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Grp XNH, MS F664, Los Alamos, NM 87545 USA. NR 26 TC 5 Z9 5 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD JAN-FEB PY 1998 VL 21 IS 1-2 BP 77 EP 88 DI 10.1016/S0734-743X(97)00029-8 PG 12 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA YR695 UT WOS:000071521000007 ER PT J AU Glass, SJ Hosking, FM Loehman, RE Mahoney, FM Pollinger, JP Stephens, JJ Vianco, PT AF Glass, SJ Hosking, FM Loehman, RE Mahoney, FM Pollinger, JP Stephens, JJ Vianco, PT TI Silicon nitride joining for high temperature applications SO INTERNATIONAL JOURNAL OF MATERIALS & PRODUCT TECHNOLOGY LA English DT Article DE active braze; ceramic; glass; silicon nitride (Si3N4) ID SIALON-GLASS ADHESIVES; MECHANICAL-PROPERTIES AB Techniques for joining silicon nitride (Si3N4) to itself and to structural metal alloys for high-temperature applications were developed. Two materials joining systems were used; high-temperature brazes and oxynitride glasses. Three commercially available precious metal braze alloys and modifications of these brazes were evaluated for applications in which Si3N4 is to be joined to structural metals. Active metal coatings were used to promote wetting and optimise the bonding to the Si3N4. Average bend strengths of 330 MPa at room temperature and 160 MPa at test temperatures as high as 800 degrees C were measured for the brazed Si3N4 specimens. Oxynitride glass joints were formed after reaction of an oxide glass from the yttria-alumina-silica ternary system with the Si3N4. Extensive interdiffusion between the glass joint and the Si3N4 plus Si3N4 dissolution into the glass joint promoted the formation of a strong bond. Average four-point bend strengths were 370 MPa at room temperature and 490 MPa at 1000 degrees C. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Norton Co, Worcester, MA 01615 USA. AlliedSignal Ceram Components, Torrance, CA 90509 USA. NR 18 TC 1 Z9 1 U1 1 U2 2 PU INDERSCIENCE ENTERPRISES LTD PI GENEVA AEROPORT PA WORLD TRADE CENTER BLDG 110 AVE LOUSIS CASAI CP 306, CH-1215 GENEVA AEROPORT, SWITZERLAND SN 0268-1900 J9 INT J MATER PROD TEC JI Int. J. Mater. Prod. Technol. PY 1998 VL 13 IS 1-2 BP 56 EP 76 PG 21 WC Materials Science, Multidisciplinary SC Materials Science GA 103AV UT WOS:000074959200006 ER PT J AU Zacharia, T Chen, Y Dress, W AF Zacharia, T Chen, Y Dress, W TI Modelling of fundamental phenomena in gas tungsten arc welds SO INTERNATIONAL JOURNAL OF MATERIALS & PRODUCT TECHNOLOGY LA English DT Article DE arc-metal interaction; arc-pool interaction; cellular automata; computer simulation; fluid flow; gas tungsten arc; heat flow; microscopic models; welding processes ID FLUID-FLOW; PENETRATION; SIMULATION; POOLS AB Practical application of new and advanced materials is often limited by the quality and reliability of welding processes. Specific demands of properties and performance can only be met by controlling the microstructure of the weld joint. While there continues to be an increased emphasis on the reliability and uniformity of engineered and manufactured components, a fundamental understanding of advanced and conventional joining processes has proven to be somewhat inadequate, Advanced mathematical techniques and computer simulations play a major role in providing enhanced understanding of conventional and advanced materials processing. Development and application of mathematical models and computer simulation techniques can provide a quantitative understanding of advanced materials and processing technologies and will minimise the need for expensive and time-consuming trial-and-error product development. This paper briefly describes current research in modelling of weld processes, emphasising recent development in the prediction of weld solidification structures. C1 Oak Ridge Natl Lab, Div Met & Ceram, Modelling & Simulat Grp, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Instrumentat & Controls, Oak Ridge, TN 37831 USA. OI Zacharia, Thomas/0000-0001-6463-5425 NR 31 TC 2 Z9 3 U1 0 U2 4 PU INDERSCIENCE ENTERPRISES LTD PI GENEVA AEROPORT PA WORLD TRADE CENTER BLDG 110 AVE LOUSIS CASAI CP 306, CH-1215 GENEVA AEROPORT, SWITZERLAND SN 0268-1900 J9 INT J MATER PROD TEC JI Int. J. Mater. Prod. Technol. PY 1998 VL 13 IS 1-2 BP 77 EP 88 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA 103AV UT WOS:000074959200007 ER PT J AU Shu, JY AF Shu, JY TI Scale-dependent deformation of porous single crystals SO INTERNATIONAL JOURNAL OF PLASTICITY LA English DT Article ID STRAIN GRADIENT PLASTICITY; VOID GROWTH; SOLIDS; LOCALIZATION; COALESCENCE; MEDIA AB An elasto-viscoplastic strain gradient crystal plasticity formulation is applied to study the deformation of a porous single crystal and its macroscopic stress carrying capacity under plane strain condition. Both uniaxial and biaxial loadings are considered. Computational model is a unit cell containing one single void. Attention is focused on investigating the effects of varying void size with respect to a representative constitutive length scale l, at arbitrarily fixed void volume fractions, on its growth rate, the local strain distribution around the void and the macroscopic stress sustained by the material. It is found that both void growth rate and the local strain gradient is decreased by several times when its radius is reduced to l. This indicates that "small" voids are less susceptible to growth than 'large' voids. Computations also show that strain gradient effects significantly elevates the macroscopic stress, especially under large biaxiality of loading. Overall, as the void size increases, the gradient theory predictions gradually approach the classical theory predictions which are size-independent. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Lawrence Livermore Natl Lab, Dept Engn, Livermore, CA 94550 USA. RP Lawrence Livermore Natl Lab, Dept Engn, Livermore, CA 94550 USA. EM jyshu@llnl.gov NR 35 TC 46 Z9 56 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0749-6419 EI 1879-2154 J9 INT J PLASTICITY JI Int. J. Plast. PY 1998 VL 14 IS 10-11 BP 1085 EP 1107 DI 10.1016/S0749-6419(98)00048-5 PG 23 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA 158ZL UT WOS:000078147300007 ER PT J AU Khaleel, MA Johnson, KI Hamilton, CH Smith, MT AF Khaleel, MA Johnson, KI Hamilton, CH Smith, MT TI Deformation modeling of superplastic AA-5083 SO INTERNATIONAL JOURNAL OF PLASTICITY LA English DT Article ID TEXTURE; ALUMINUM; ALLOY AB The superplastic deformation characteristics of a modified aluminum alloy were investigated at temperature range from 500 to 550 degrees C. The alloy chemical composition was 4.69% Mg, 1.56% Mn, 0.177% Cr, 0.03% Si, and 0.07% Fe by weight. Total tensile elongations as high as 750% were observed at lower strain rates. A non-isothermal constitutive equation, that includes the evolution of grain size, was established and implemented in a finite element code. Numerical simulations of the uniaxial tension specimen were performed, and good agreement between the testing and the modeling results was obtained. A pressure control algorithm for the blow forming model was developed based on an averaging scheme that considered a subset of finite elements with the highest strain rate. A pressure history was generated from the finite element simulations for a constant target strain rate of 1x10(-3) s(-1). When these pressure histories were used in tray forming experiments, good agreement was obtained between the forming and modeling results. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Pacific NW Lab, Engn Mech Grp, Richland, WA 99352 USA. Washington State Univ, Sch Mech & Mat Engn, Pullman, WA 99164 USA. Pacific NW Lab, Mat Proc Grp, Richland, WA 99352 USA. RP Pacific NW Lab, Engn Mech Grp, POB 999, Richland, WA 99352 USA. EM ma.khaleel@pnl.gov OI khaleel, mohammad/0000-0001-7048-0749 NR 27 TC 27 Z9 29 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0749-6419 EI 1879-2154 J9 INT J PLASTICITY JI Int. J. Plast. PY 1998 VL 14 IS 10-11 BP 1133 EP 1154 DI 10.1016/S0749-6419(98)00051-5 PG 22 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA 158ZL UT WOS:000078147300009 ER PT J AU Stahlman, EJ Cochran, JK AF Stahlman, EJ Cochran, JK TI Dynamic metamodelling in capacity planning SO INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH LA English DT Article ID BREAKDOWNS AB Traditional capacity planning modelling techniques focus on the steady-state behaviour of a system. This is because transient behaviour complicates the problem, both conceptually and analytically, and solutions tend to be time consuming. Nevertheless, the transient behaviour of a system is often of equal consequence to that of the steady-state behaviour and requires methods for characterization. Further, today's increasingly powerful personal computers allow complex, dynamic behaviours to be modelled in a timely manner. This paper presents a model for incorporating dynamic behaviour into capacity planning. The model is demonstrated through a case study of a telephone order entry system. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Cochran, JK (reprint author), Pacific NW Lab, POB 999,MSIN K8-23, Richland, WA 99352 USA. NR 13 TC 8 Z9 8 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0020-7543 J9 INT J PROD RES JI Int. J. Prod. Res. PD JAN PY 1998 VL 36 IS 1 BP 197 EP 209 DI 10.1080/002075498194001 PG 13 WC Engineering, Industrial; Engineering, Manufacturing; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA YT719 UT WOS:000071636100011 ER PT J AU Lucas, JN AF Lucas, JN TI Cytogenetic signature for ionizing radiation SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID IN-SITU HYBRIDIZATION; FREQUENCY; LYMPHOCYTES; IRRADIATION; EXCHANGES; EXPOSURE AB A stable, easily measurable biological 'signature' for past exposure to densely ionizing radiation would be of significant value to estimate environmental radiation risk. Defined here, the S-ratio is the ratio of complete to incomplete chromosome translocations. It constitutes a clastogenic signature that appears to be stable over time, independent of dose, and varies inversely with the relative biological effectiveness (RBE) of the radiation. In vitro measurements resulted in a ratio of similar to 2 for densely ionizing radiation (Fe-56 and C-12 ions) in contrast to a Value of similar to 10 for sparsely ionizing radiation (X-and gamma-rays). The measured ratio was similar to 2 for bleomycin and benzene. Such a distinctive clastogenic signature should facilitate better estimates of neutron dose for A-bomb survivors, as well as a causal connection between early exposure to densely ionizing radiation and late development of cancer. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Lucas, JN (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-452, Livermore, CA 94551 USA. NR 23 TC 36 Z9 36 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD JAN PY 1998 VL 73 IS 1 BP 15 EP 20 DI 10.1080/095530098142662 PG 6 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA YT713 UT WOS:000071635500002 PM 9464473 ER PT J AU Olsson, P Black, M Capala, J Coderre, J Hartman, T Makar, M Malmquist, J Pettersson, J Tilly, N Sjoberg, S Carlsson, J AF Olsson, P Black, M Capala, J Coderre, J Hartman, T Makar, M Malmquist, J Pettersson, J Tilly, N Sjoberg, S Carlsson, J TI Uptake, toxicity and radiation effects of the boron compounds DAAC-1 and DAC-1 in cultured human glioma cells SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID NEUTRON-CAPTURE THERAPY; EPIDERMAL GROWTH-FACTOR; IN-VITRO; CARBORANE; BINDING AB Purpose: To study the uptake, toxicity and radiation effects in vitro of a diol-amino acid-carborane (DAAC-I) and make comparisons with the previously studied diol-amine-carborane (DAC-I). Materials and methods: Toxicity and radiation effects were studied with clonogenic survival, uptake by measuring the cellular boron content and the subcellular distribution was investigated after organelle separation with centrifugation. The studied cell line was human glioma U343. Results: DAAC-I showed an accumulation of 1-1.5 times, compared with the culture medium, and was non-toxic up to 47 mu g boron/ml. The accumulation of DAC-I was about 90 times, but toxic effects were detectable already at the concentration 5 mu g boron/ml. None of the compounds was localized in the cell nucleus. Following irradiation with thermal neutrons, DEC-I was about 2.5 times more effective than DAAC-1 and about 4.9 times more effective than neutrons alone, at the survival level 0.2. The dose modifying factors, when compared with the neutron beam alone, were for both DAAC-1 and DAC-1 about 1.5 and about 5 when compared with Co-60-gamma-radiation. Conclusions: DAAC-1 was less toxic than DAC-1 but gave less accumulation of boron. Both substances gave significant boron-dependent cell inactivation when the lest cells were exposed to thermal neutrons. C1 Univ Uppsala, Dept Diagnost Radiol, Dept Biomed Radiat Sci, S-75121 Uppsala, Sweden. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Univ Uppsala, Inst Chem, Dept Organ Chem, S-75121 Uppsala, Sweden. Univ Uppsala, Inst Chem, Dept Analyt Chem, S-75121 Uppsala, Sweden. Univ Uppsala Hosp, Dept Oncol, S-75185 Uppsala, Sweden. RP Olsson, P (reprint author), Univ Uppsala, Dept Diagnost Radiol, Dept Biomed Radiat Sci, POB 535, S-75121 Uppsala, Sweden. NR 13 TC 7 Z9 7 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD JAN PY 1998 VL 73 IS 1 BP 103 EP 112 DI 10.1080/095530098142752 PG 10 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA YT713 UT WOS:000071635500011 PM 9464482 ER PT J AU de Arellano-Lopez, AR Smirnov, BI Schuldies, JJ Park, ET Goretta, KC Routbort, JL AF de Arellano-Lopez, AR Smirnov, BI Schuldies, JJ Park, ET Goretta, KC Routbort, JL TI Fracture and creep of an Al2O3-SiC (whisker) TiC (particle) composite SO INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS LA English DT Article DE ceramic-matrix composites; fracture; creep; electrodischarge machining ID MATRIX COMPOSITES; CERAMICS; DEFORMATION; MECHANISMS; DEPENDENCE; ALUMINA AB High-temperature fracture strength and compressive creep of an electrodischarge-machinable composite, Al2O3-30.9 vol.% SiC whiskers-23 vol.% TiC particles have been studied to 1200 degrees C and 1450 degrees C, respectively, in inert atmosphere. Microstructures of fractured and deformed specimens were examined using scanning and transmission electron microscopy. Fast fracture occurred at T less than or equal to 1200 degrees C, Steady-state creep was achieved for T > 1350 degrees C at stresses <80 MPa, with the rate-controlling mechanism being partially unaccommodated grain-boundary sliding, with a stress exponent of approximate to 1 and an activation energy of approximate to 470 kJ/mol. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Sevilla, Dept Fis Mat Condensada, E-41080 Seville, Spain. Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia. Indian Ceram Technol, Ann Arbor, MI 48103 USA. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP de Arellano-Lopez, AR (reprint author), Univ Sevilla, Dept Fis Mat Condensada, POB 1065, E-41080 Seville, Spain. OI R. de Arellano Lopez, Antonio/0000-0002-7443-0244 NR 19 TC 1 Z9 1 U1 2 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0263-4368 J9 INT J REFRACT MET H JI Int. J. Refract. Met. Hard Mat. PY 1998 VL 16 IS 4-6 BP 337 EP 341 DI 10.1016/S0263-4368(98)00037-7 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 158BZ UT WOS:000078097300011 ER PT J AU Williams, TO Addessio, FL AF Williams, TO Addessio, FL TI A dynamic model for laminated plates with delaminations SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article ID LOW-VELOCITY IMPACT; COMPOSITE STRUCTURES; FREE-VIBRATION AB A generalized theory for laminated plates, including delamination, is developed. The laminate model is based on a generalized displacement formulation implemented at the layer level, The equations of motion for a layer, which are explicitly coupled with both the interfacial traction continuity and the interfacial displacement jump conditions between layers, are used to develop the governing equations for a laminated composite plate. The delamination behavior can be modeled using any general constitutive fracture law. The interfacial displacement jumps are expressed in an internally consistent fashion in terms of the fundamental unknown interfacial tractions. The current theory imposes no restrictions on the size, location, distribution, or direction of growth bf the delaminations. Therefore, the theory can predict the initiation and growth of delaminations at any location as well as interactive effects between delaminations at different locations within the laminate. The proposed theory is used to consider the dynamic response of laminated plates in cylindrical bending. First it is shown that the dynamic implementation agrees well with the exact predictions of a plate under static loading conditions. Static, cylindrical bending is considered to validate the numerical implementation. Next, different dynamic loading cases are considered. First, the required level of discretization through the thickness of the laminate necessary to accurately capture the wave propagation characteristics for monotonic tensile loading transverse to the plate is determined. Next, the influence of the delamination on the free vibration behavior of a plate is considered. It is shown that the presence of delaminations can result in significant deviations from the perfectly bonded free vibration behavior. Finally, the plate is subjected to dynamic loading conditions that demonstrate the influence of internal wave interactions on the overall behavior of the plate. (C) 1997 Elsevier Science Ltd. RP Williams, TO (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 27 TC 18 Z9 18 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD JAN PY 1998 VL 35 IS 1-2 BP 83 EP & DI 10.1016/S0020-7683(97)00055-3 PG 23 WC Mechanics SC Mechanics GA YJ567 UT WOS:A1998YJ56700006 ER PT J AU Anderson, LE AF Anderson, LE TI Extremely low frequency fields and cancer: Laboratory studies SO INTERNATIONAL JOURNAL OF TOXICOLOGY LA English DT Article ID ALTERNATING MAGNETIC-FIELD; RAT-LIVER FOCI; TUMOR PROMOTION; MOUSE-SKIN; EXPOSURE; MICE; MODEL C1 Battelle, PNL, Bioelectromagnet Sect, Richland, WA 99352 USA. RP Anderson, LE (reprint author), Battelle, PNL, Bioelectromagnet Sect, POB 999, Richland, WA 99352 USA. NR 21 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 1091-5818 J9 INT J TOXICOL JI Int. J. Toxicol. PY 1998 VL 17 SU 3 BP 47 EP 57 PG 11 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA 117DD UT WOS:000075764600005 ER PT S AU Seppala, LG AF Seppala, LG BE Gardner, LR Thompson, KP TI The IODC98 optical design problem: method of progressing from an achromatic to an apochromatic design. SO INTERNATIONAL OPTICAL DESIGN CONFERENCE 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 1998 International Optical Design Conference CY JUN 08-12, 1998 CL KONA, HI SP OSA, Opt Soc Amer, SPIE Int Soc Opt Engn C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Seppala, LG (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 5508,L-527, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2937-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3482 BP 10 EP 20 DI 10.1117/12.321992 PG 11 WC Optics SC Optics GA BL97D UT WOS:000077312500002 ER PT S AU English, RE Laumann, CW Miller, JL Seppala, LG AF English, RE Laumann, CW Miller, JL Seppala, LG BE Gardner, LR Thompson, KP TI Optical system design of the National Ignition Facility SO INTERNATIONAL OPTICAL DESIGN CONFERENCE 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 1998 International Optical Design Conference CY JUN 08-12, 1998 CL KONA, HI SP OSA, Opt Soc Amer, SPIE Int Soc Opt Engn AB The National Ignition Facility (NIF) is a laser fusion facility being constructed at Lawrence Livermore National Laboratory (LLNL). The neodymium-doped phosphate glass pulsed laser system will produce over 3.5MJ of laser energy at a fundamental lasing wavelength of 1.053 mu m (1 omega). The final optics assembly contains a pair of crystals (KDP/KD*P) and a focusing lens to convert the light by sum-frequency-mixing to 3 omega (lambda=0.35 mu m) and focus 1.8MJ onto the target. The NIF optical system is large and complex. To give some perspective the NIF building is roughy 200 meters long x 85 meters wide. There are approximately 7500 optical components in the large aperture laser system - lenses, mirrors, polarizers, laser slabs, crystals, and windows each with a clear aperture greater than 40cm square. The front-end of the laser system contains more than 8000 smaller (5-15cm) precision laser components. In this paper we will describe the optical system configuration, layout, and general design considerations. We will explain the path of the pulse through the various subsystems. Some of the top-level optical system and sub-system design requirements will be presented. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP English, RE (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-527, Livermore, CA 94551 USA. NR 0 TC 4 Z9 5 U1 1 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2937-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3482 BP 726 EP 736 PG 11 WC Optics SC Optics GA BL97D UT WOS:000077312500082 ER PT S AU English, RE Miller, JL AF English, RE Miller, JL BE Gardner, LR Thompson, KP TI Ghost reflection analysis for the main laser of the National Ignition Facility SO INTERNATIONAL OPTICAL DESIGN CONFERENCE 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 1998 International Optical Design Conference CY JUN 08-12, 1998 CL KONA, HI SP OSA, Opt Soc Amer, SPIE Int Soc Opt Engn AB Ghost reflections are a major consideration in the optical design of the National Ignition Facility (NIF). The first-order layout (e.g., spacing between components), the lens shape, and the dimensions of the building are strongly affected. In this paper we will describe the principal ghost reflections that drive the system configuration. Several specific examples will be shown to illustrate how dangerous ghost reflections are avoided and stray light concerns are managed. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP English, RE (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-527, Livermore, CA 94551 USA. NR 0 TC 2 Z9 2 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2937-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3482 BP 748 EP 753 PG 6 WC Optics SC Optics GA BL97D UT WOS:000077312500084 ER PT S AU Blankenbecler, R AF Blankenbecler, R BE Gardner, LR Thompson, KP TI Diffusion theory and macro-GRIN material with prescribable index profiles SO INTERNATIONAL OPTICAL DESIGN CONFERENCE 1998 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 1998 International Optical Design Conference CY JUN 08-12, 1998 CL KONA, HI SP OSA, Opt Soc Amer, SPIE Int Soc Opt Engn DE gradient index; GRIN; axial gradient; radial gradient; optical design; glass lines; unique optical systems; high performance AB Optical material that is described by a line on the glass map, as opposed to the point describing homogeneous material, promises new types of optical design applications of improved performance. These will incorporate lenses of gradient refractive material with either axial or radial profiles. These materials open up the designer's available parameter space to include a controlled gradient in both index and dispersion. The availability of prescribable GRIN material allows unusual lens geometries that will be introduced and illustrated. The range of applications for axial and radial GRIN lenses overlap but are not identical. Prescribable radial GRIN material has a much broader range of applications. The main subject of this talk will be the fusion/diffusion process used to produce macro radial and axial GRIN material. This process is simple, repeatable, and applicable to mass production for both geometries. The advantage of GRIN technology and its availability in commercial lens design programs provides the opportunity to push performance and reduce cost. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Blankenbecler, R (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2937-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3482 BP 766 EP 779 DI 10.1117/12.321978 PG 14 WC Optics SC Optics GA BL97D UT WOS:000077312500087 ER PT J AU Cada, GF AF Cada, GF TI Efforts to reduce the impacts of hydroelectric power production on reservoir fisheries in the United States SO INTERNATIONAL REVIEW OF HYDROBIOLOGY LA English DT Article; Proceedings Paper CT 3rd International Conference on Reservoir Limnology and Water Quality CY AUG 11-15, 1997 CL CESKE BUDEJOVICE, CZECH REPUBLIC DE upstream fish passage; turbine passage; fish screen; instream flow releases; hydroelectric ID HYDROPOWER AB Research into the environmental effects of hydroelectric power production in the United States has focused increasingly on resident and migratory fish populations. Hydropower darns and reservoirs can block fish movements in both upstream and downstream directions. These movements are essential for important stocks of anadromous and catadromous fish. In addition, some strictly freshwater fish may move long distances within a river during their life cycles. A dam can pose an impassable barrier for fish trying to move upstream unless mitigation measures in the form of ladders or lifts are provided. Fish moving downstream to the sea may become disoriented when they encounter static water within a reservoir. Both resident and migratory fish may be injured or killed by passing through the turbine or over the spillway. In the United States, a variety of organizations conduct applied research to develop measures to (1) enhance fish passage, (2) reduce the numbers of fish that are drawn into the turbine intakes, and (3) reduce the injury and mortality rates of fish that pass through the turbines. Examples of these efforts from a variety of river systems and hydroelectric power plants are described. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Cada, GF (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 13 TC 3 Z9 3 U1 1 U2 9 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 1434-2944 J9 INT REV HYDROBIOL JI Int. Rev. Hydrobiol. PY 1998 VL 83 SI SI BP 43 EP 50 PG 8 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 167TW UT WOS:000078647300006 ER PT S AU LaVigne, GF Miller, SL AF LaVigne, GF Miller, SL GP IEEE IEEE TI A performance analysis system for MEMS using automated imaging methods SO INTERNATIONAL TEST CONFERENCE 1998, PROCEEDINGS SE INTERNATIONAL TEST CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT International Test Conference 1998 CY OCT 18-23, 1998 CL WASHINGTON, D.C. SP IEEE Comp Soc, Test Technol Tech Comm, IEEE Philadelphia Sect AB The ability to make in-situ performance measurements of MEMS operating at high speeds has been demonstrated using a new image analysis system. Significant improvements in performance and reliability have directly resulted from the use of this system. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP LaVigne, GF (reprint author), Sandia Natl Labs, POB 5800,M-S 1080, Albuquerque, NM 87185 USA. NR 0 TC 14 Z9 14 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1089-3539 BN 0-7803-5093-6 J9 INT TEST CONF P PY 1998 BP 442 EP 447 DI 10.1109/TEST.1998.743184 PG 6 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BL99G UT WOS:000077394000052 ER PT B AU Yoshimi, K Yoo, MH Hanada, S AF Yoshimi, K Yoo, MH Hanada, S BE Baker, I Noebe, RD George, EP TI Room-temperature serrated-flow behavior in Fe-rich FeAl under vacancy supersaturation SO INTERSTITIAL AND SUBSTITUTIONAL SOLUTE EFFECTS IN INTERMETALLICS LA English DT Proceedings Paper CT 2nd International Symposium on Interstitial and Substitutional Solute Effects in Intermetallics, at the 1998 TMS Fall Meeting CY OCT 11-15, 1998 CL ROSEMONT, IL SP Minerals Met & Mat Soc AB In Fe-rich FeAl, serrated plastic-flow behavior has been observed for the first time at room temperature. Serration on the tensile stress-strain curve occurs in single crystals that retained a supersaturation of thermal vacancies after fast-cooling from the annealing temperature of 1173 K. In contrast to conventional serrated flow, the serrated flow in FeAl is associated with work hardening, and it becomes more pronounced with increasing Al content from 33 to 44 mol.%. The experimental results are interpreted in terms of the dynamic interaction of ((1) over bar 01)[111] superdislocations with the excess thermal vacancies and their clusters and the successive double cross-slip of screw superdislocations at the moving front of a slip band. The strong dependence on alloy composition and the lack of strain-rate sensitivity are discussed. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Yoshimi, K (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-413-5 PY 1998 BP 39 EP 49 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BM06Y UT WOS:000077538900003 ER PT B AU Cohron, JW George, EP Zee, RH AF Cohron, JW George, EP Zee, RH BE Baker, I Noebe, RD George, EP TI Effects of interstitial boron and alloy stoichiometry on environmental effects in FeAl SO INTERSTITIAL AND SUBSTITUTIONAL SOLUTE EFFECTS IN INTERMETALLICS LA English DT Proceedings Paper CT 2nd International Symposium on Interstitial and Substitutional Solute Effects in Intermetallics, at the 1998 TMS Fall Meeting CY OCT 11-15, 1998 CL ROSEMONT, IL SP Minerals Met & Mat Soc AB Room-temperature tensile tests were conducted on B-doped (300 wppm) and B-free polycrystalline FeAl alloys containing 37, 40, 45 and 48 at. % aluminum in pure hydrogen gas at pressures in the range of 10(-8) to 10(3) Pa. The ductilities of both B-free and B-doped FeAl decreased with increasing Al content. However, at a given Al level, the ductility of B-doped FeAl was higher than that of its B-free counterpart. Fracture mode was independent of environment and dependent mainly on stoichiometry. Ductility was found to be very sensitive to environment, particularly in the lower Al alloys. Alloys that exhibited adequate ductility in UHV (> 10 %) showed a decrease in elongation to fracture with increasing hydrogen pressure; this embrittlement was harder to detect in the more brittle alloys. Tests conducted in dry hydrogen gas result in greater ductilities than those conducted in air, indicating that water vapor is more detrimental than Hz to the ductility of FeAl alloys. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Cohron, JW (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI George, Easo/L-5434-2014 NR 0 TC 1 Z9 1 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-413-5 PY 1998 BP 71 EP 81 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BM06Y UT WOS:000077538900005 ER PT B AU Pike, LM Liu, CT Anderson, IM Chang, YA AF Pike, LM Liu, CT Anderson, IM Chang, YA BE Baker, I Noebe, RD George, EP TI Solute hardening and softening effects in B2 nickel aluminides SO INTERSTITIAL AND SUBSTITUTIONAL SOLUTE EFFECTS IN INTERMETALLICS LA English DT Proceedings Paper CT 2nd International Symposium on Interstitial and Substitutional Solute Effects in Intermetallics, at the 1998 TMS Fall Meeting CY OCT 11-15, 1998 CL ROSEMONT, IL SP Minerals Met & Mat Soc AB The effect of substitutional solute additions including Fe, Mn, and Pd on the hardness of B2-ordered NiAl alloys was investigated. The solid solution hardening behavior of intermetallics is more complex than that of typical metallic solid solutions because of complications arising from the site preference of the solute as well as the effects of the solute on the concentrations of other point defects, e.g. vacancies and anti-site defects. For this reason, care was taken to experimentally establish solute site preferences and point defect concentrations in the NiAl alloys before analyzing the hardness data. By taking these factors into account it was possible to rationalize the observed unusual hardening effects. Three distinct categories of solid solution hardening behavior were encountered. The first was hardening by the solute addition itself. This was observed in the case of Pd additions to Al-poor NiAl. However, when Fe or Mn is added to Al-poor NiAl a second category is observed; these elements are seen to soften the material. The third category of behavior is observed when Fe is added to NiAl with a constant Al concentration of 50 at. %. In this case it is vacancies, rather than solute atoms, which harden the material. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Pike, LM (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 0 TC 6 Z9 6 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-413-5 PY 1998 BP 149 EP 162 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BM06Y UT WOS:000077538900010 ER PT B AU Liu, CT Maziasz, PJ Larson, DJ AF Liu, CT Maziasz, PJ Larson, DJ BE Baker, I Noebe, RD George, EP TI Effects of B and W additions on microstructures and mechanical properties of dual-phase lamellar TiAl alloys SO INTERSTITIAL AND SUBSTITUTIONAL SOLUTE EFFECTS IN INTERMETALLICS LA English DT Proceedings Paper CT 2nd International Symposium on Interstitial and Substitutional Solute Effects in Intermetallics, at the 1998 TMS Fall Meeting CY OCT 11-15, 1998 CL ROSEMONT, IL SP Minerals Met & Mat Soc AB This paper provides a comprehensive review of our recent work on the effects of B and W additions on lamellar microstructure and mechanical properties of dual-phase TiAl alloys. The microstructural features in lamellar TiAl alloys were characterized by APFIM and TEM, and the mechanical properties were evaluated by tensile testing at temperatures to 1000 degrees C. APFIM analyses indicate that W tends to segregate strongly to gamma/gamma and gamma/alpha(2), interfaces, whereas B does not. Additions of B and W together refine the lamellar structures in TiAl alloys, and the beneficial effect of B is believed to be with its promotion of nucleation of gamma laths whereas the W effect is retardation of lamellar growth. Alloying with 0.2% W substantially improves the yield strength of Ti-47Al-2Cr-2Nb at room and elevated temperatures. The Hall-Fetch equation is applicable to the yield strength of lamellar TiAl alloys. The strengthening effect of W mainly comes from its refinement of the lamellar spacing, rather than from a classic solute hardening effect. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Liu, CT (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. OI Maziasz, Philip/0000-0001-8207-334X; Liu, Chain Tsuan/0000-0001-7888-9725 NR 0 TC 7 Z9 7 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-413-5 PY 1998 BP 179 EP 188 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BM06Y UT WOS:000077538900012 ER PT B AU Hsiung, LM Nieh, TG AF Hsiung, LM Nieh, TG BE Baker, I Noebe, RD George, EP TI Creep deformation of lamellar TiAl alloys controlled by viscous glide of interfacial dislocations SO INTERSTITIAL AND SUBSTITUTIONAL SOLUTE EFFECTS IN INTERMETALLICS LA English DT Proceedings Paper CT 2nd International Symposium on Interstitial and Substitutional Solute Effects in Intermetallics, at the 1998 TMS Fall Meeting CY OCT 11-15, 1998 CL ROSEMONT, IL SP Minerals Met & Mat Soc AB Creep mechanisms of fully-lamellar (FL) TiAl with a refined microstructure (gamma lamella: 100 - 300 nm thick, alpha(2) lamella: 10 - 100 nm thick) have been investigated. A nearly linear creep behavior (i.e. the steady-state creep rate is linearly proportional to the applied stress) is observed when the alloy is creep deformed at low applied stresses (< 400 MPa) and intermediate temperatures (650 - 810 degrees C). Since the operation and multiplication of lattice dislocations within both gamma and alpha(2) lamellae are very limited in a low stress level as a result of a refined lamellar microstructure, creep mechanisms based upon glide and/or climb of lattice dislocations become insignificant. Instead, a cooperative glide of preexisting interfacial dislocations on both gamma/alpha(2) and gamma/gamma interfaces (i.e. interface sliding) has found to be a predominant deformation mechanism. According to the observed interfacial substructure and the measured activation energy for creep, it is proposed that the viscous Slide of interfacial dislocations controls the creep deformation of refined FL-TiAl in the intermediate-temperature and low-stress regime. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Hsiung, LM (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-369,POB 808, Livermore, CA 94551 USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-413-5 PY 1998 BP 201 EP 210 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BM06Y UT WOS:000077538900014 ER PT B AU Anderson, IM AF Anderson, IM BE Baker, I Noebe, RD George, EP TI The role of ALCHEMI in understanding the properties of ordered intermetallic alloys SO INTERSTITIAL AND SUBSTITUTIONAL SOLUTE EFFECTS IN INTERMETALLICS LA English DT Proceedings Paper CT 2nd International Symposium on Interstitial and Substitutional Solute Effects in Intermetallics, at the 1998 TMS Fall Meeting CY OCT 11-15, 1998 CL ROSEMONT, IL SP Minerals Met & Mat Soc AB After one and one-half decades of development, ALCHEMI is approaching the status of an established analytical technique. Many of the problems that have plagued ALCHEMI, especially for the analysis of ordered intermetallic alloys, are now well understood, and accurate site-distributions can be extracted from a variety of intermetallic alloys. This paper begins with an overview of the factors that can lead to large systematic errors or gross misinterpretations of ALCHEMI data, with illustrations from a variety of ordered intermetallic alloys. The paper concludes with a discussion of ALCHEMI in the broader context of understanding the properties of ordered intermetallic alloys. The results of systematic studies are used to illustrate the role of ALCHEMI in determining the competing effects of thermodynamic and kinetic factors during alloy processing and the correlation of alloy properties with the atomic site distributions on which the properties ultimately depend. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Anderson, IM (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-413-5 PY 1998 BP 325 EP 340 PG 16 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BM06Y UT WOS:000077538900022 ER PT S AU Monteiro, OR Anders, A AF Monteiro, OR Anders, A GP IEEE IEEE IEEE TI Vacuum-arc-generated macroparticles in the nanometer range SO ISDEIV: XVIIITH INTERNATIONAL SYMPOSIUM ON DISCHARGES AND ELECTRICAL INSULATION IN VACUUM - PROCEEDINGS, VOLS 1 AND 2 SE PROCEEDINGS - INTERNATIONAL SYMPOSIUM ON DISCHARGES AND ELECTRICAL INSULATION IN VACUUM LA English DT Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL AB Micron and sub-micron "macroparticles" are produced along with the plasma at vacuum are cathode spots. Published data refer to the size range 0.2 - 100 mu m. The lower limit is determined by the resolution of the equipment used (usually scanning electron microscopes). In the present study we focus on the detection and characterization of nanosize macroparticles ("nanoparticles") using atomic force microscopy and field-emission scanning electron microscopy. New information is gathered on material-dependent size distribution functions as well as on the effectiveness of magnetic filtering for nanoparticles. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Monteiro, OR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. OI Anders, Andre/0000-0002-5313-6505 NR 0 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1093-2941 BN 0-7803-3953-3 J9 P INT SYMP DISCH EL PY 1998 VL 18 BP 593 EP 596 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Physics GA BM06E UT WOS:000077494100136 ER PT S AU Anders, A AF Anders, A GP IEEE IEEE IEEE TI Plasma fluctuations, Local Partial Saha Equilibrium, and the broadening of vacuum-arc ion charge state distributions SO ISDEIV: XVIIITH INTERNATIONAL SYMPOSIUM ON DISCHARGES AND ELECTRICAL INSULATION IN VACUUM - PROCEEDINGS, VOLS 1 AND 2 SE PROCEEDINGS - INTERNATIONAL SYMPOSIUM ON DISCHARGES AND ELECTRICAL INSULATION IN VACUUM LA English DT Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL AB Charge state distributions (CSDs) of Fe, Co, Zr, Nb, Hf, Ag, Pt, Au ions produced at vacuum are cathode spots are investigated without often-used averaging procedures. Statistical results are used to evaluate the contribution of fluctuations to the broadening of averaged CSDs. Calculations of Saha equations in the Debye-Huckel approximation are often successful in replicating experimental CSDs even when using the simple model of "instantaneous freezing". This allows us to use charge state spectrometry as a plasma diagnostic tool for the dense plasma near the cathode spot. Typically, total heavy particle (atoms and ions) densities and electron temperatures of 10(24) - 10(25)m(-3) and 3-4 eV have been measured this way at the transition zone from equilibrium to non-equilibrium, the "event horizon." It was also found that CSDs for some elements such as Co, Ag, and Hf cannot be accurately simulated with the assumption of instantaneous freezing. Here, a more gradual transition to non-equilibrium occurs. This transition can be described by the model of Partial Local Saha equilibrium. Finally, an axial magnetic field was found to soften the transition to nonequilibrium thus causing broadening of experimental CSDs. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Anders, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. OI Anders, Andre/0000-0002-5313-6505 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1093-2941 BN 0-7803-3953-3 J9 P INT SYMP DISCH EL PY 1998 VL 18 BP 617 EP 624 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Physics GA BM06E UT WOS:000077494100142 ER PT S AU Cuneo, ME AF Cuneo, ME GP IEEE IEEE IEEE TI The effects of electrode cleaning and conditioning on the performance of high-energy, pulsed-power devices SO ISDEIV: XVIIITH INTERNATIONAL SYMPOSIUM ON DISCHARGES AND ELECTRICAL INSULATION IN VACUUM - PROCEEDINGS, VOLS 1 AND 2 SE PROCEEDINGS - INTERNATIONAL SYMPOSIUM ON DISCHARGES AND ELECTRICAL INSULATION IN VACUUM LA English DT Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL AB High-energy pulsed-power devices routinely access field strengths above those at which broad-area, cathode-initiated, high-voltage vacuum-breakdown occur (> 1e7 - 3e7 V/m). Examples include magnetically-insulated-transmission-lines and current convolutes, high-current-density electron and ion diodes, high-power microwave devices, and cavities and other structures for electrostatic and RF accelerators. Energy deposited in anode surfaces may exceed anode plasma thermal-desorption creation thresholds on the time-scale of the pulse. Stimulated desorption by electron or photon bombardment can also lead to plasma formation on electrode or insulator surfaces. Device performance is limited above these thresholds, particularly in pulselength and energy, by the formation and expansion of plasmas formed primarily from electrode contaminants. Insitu conditioning techniques to modify and eliminate the contaminants through multiple high-voltage pulses, low base pressures, RF discharge cleaning, heating, surface coatings, and ion- and electron-beam surface treatment allow access to new regimes of performance through control of plasma formation and modification of the plasma properties. Experimental and theoretical progress from a variety of devices and small scale experiments with a variety of treatment methods will be reviewed and recommendations given for future work. C1 Sandia Natl Labs, Pulsed Power Sci Ctr, Albuquerque, NM 87185 USA. RP Cuneo, ME (reprint author), Sandia Natl Labs, Pulsed Power Sci Ctr, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1093-2941 BN 0-7803-3953-3 J9 P INT SYMP DISCH EL PY 1998 VL 18 BP 721 EP 730 PG 10 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Physics GA BM06E UT WOS:000077494100166 ER PT S AU Sampayan, SE Vitello, PA Krogh, ML Elizondo, JM AF Sampayan, SE Vitello, PA Krogh, ML Elizondo, JM GP IEEE IEEE IEEE TI Multilayer ultra-high gradient insulator technology SO ISDEIV: XVIIITH INTERNATIONAL SYMPOSIUM ON DISCHARGES AND ELECTRICAL INSULATION IN VACUUM - PROCEEDINGS, VOLS 1 AND 2 SE PROCEEDINGS - INTERNATIONAL SYMPOSIUM ON DISCHARGES AND ELECTRICAL INSULATION IN VACUUM LA English DT Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL AB We are investigating a novel insulator concept which involves the use of alternating layers of conductors and insulators with periods less than 1 mm. These structures perform many times better (about 1.5 to 4 times higher breakdown electric field) than conventional insulators in long pulse, short pulse, and alternating polarity applications. We present our ongoing studies investigating the degradation of the breakdown electric field resulting from surface roughness, the effect of gas pressure, and the performance of the insulator structure under bi-polar stress. Further, we present our initial modeling studies. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Sampayan, SE (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 0 TC 1 Z9 1 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1093-2941 BN 0-7803-3953-3 J9 P INT SYMP DISCH EL PY 1998 VL 18 BP 740 EP 743 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Physics GA BM06E UT WOS:000077494100170 ER PT J AU Kim, HJ Kim, YH Morris, JW AF Kim, HJ Kim, YH Morris, JW TI Thermal mechanisms of grain and packet refinement in a lath martensitic steel SO ISIJ INTERNATIONAL LA English DT Article DE heat treatment; structural steel; grain size; metallography; strength; toughness ID DEFORMATION INDUCED MARTENSITE; AUSTENITE; TOUGHNESS; REVERSION; SIZE AB This work was done to clarify the metallurgical mechanisms that are used in thermal treatments to refine the effective grain size of lath martensitic steels. The alloy chosen for this work was Fe-12Ni-0.25Ti, which provides a well-defined lath martensite structure in the as-quenched condition. The alloy was given four prototypic heat treatments: (1) an anneal-and-quench treatment, (2) an intercritical anneal, (3) a single or double anneal in the austenite range, and (4) a single or double reversion to austenite at a rapid heating rate. Two effective grain sizes were identified for each heat treatment: the packet size, or dimension over which adjacent martensite laths have a common crystallographic orientation, and the prior austenite grain size. The former controls the ductile-brittle transition temperature (DBTT), the latter controls intergranular embrittlement. The different heat treatments suppress the DBTT and increase resistance to intergranular embrittlement to the extent that they decrease the relevant grain size. Rapid reversion is the most successful of the heat treatments since it destroys the alignment of laths within a packet. Rapid reversion readily yields an effective grain size near 1 mu m, leading to a very low ductile-brittle transition temperature and a substantial resistance to temper or hydrogen embrittlement. C1 Korea Inst Ind Technol, Chon An Si, South Korea. Hanyang Univ, Dept Mat Sci, Seoul 133791, South Korea. Univ Calif Berkeley, Lawrence Berkeley Lab, Mat & Mol Res Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Kim, HJ (reprint author), Korea Inst Ind Technol, Chon An Si, South Korea. NR 45 TC 30 Z9 31 U1 1 U2 18 PU IRON STEEL INST JAPAN KEIDANREN KAIKAN PI TOKYO PA 9-4 OTEMACHI 1-CHOME CHIYODA-KU, TOKYO, 100, JAPAN SN 0915-1559 J9 ISIJ INT JI ISIJ Int. PY 1998 VL 38 IS 11 BP 1277 EP 1285 DI 10.2355/isijinternational.38.1277 PG 9 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 140XW UT WOS:000077096800017 ER PT J AU Van Hove, MA AF Van Hove, MA TI The adsorption sites of CO and NO molecules on metal surfaces SO ISRAEL JOURNAL OF CHEMISTRY LA English DT Article ID AUTOMATED TENSOR LEED; DYNAMICAL LEED; IV DETERMINATION; CRYSTAL-SURFACE; RH(111); GEOMETRY; CHEMISORPTION; DIFFRACTION; ABSORPTION; BENZENE AB This article briefly reviews recent structural results obtained for the adsorption of CO and NO on the closest-packed single-crystal metal surfaces. We discuss mainly the question of adsorption sites (top, bridge, hollow), in connection with site assignments based on C-O and N-O vibrational stretch frequencies. It is by now well established that, especially for high-coverage molecular structures (i.e., high-density monolayers), one cannot rely on simple site assignments based on these frequencies: molecular interactions change the frequencies, such that the frequency ranges deduced for carbonyl and nitrosyl cluster compounds are in some cases violated. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Van Hove, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Mailstop 66-200, Berkeley, CA 94720 USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 33 TC 4 Z9 4 U1 1 U2 3 PU LASER PAGES PUBL LTD PI JERUSALEM PA MERKAZ SAPIR 6/37, GIVAT SHAUL PO BOX 35409, JERUSALEM 91352, ISRAEL SN 0021-2148 J9 ISRAEL J CHEM JI Isr. J. Chem. PY 1998 VL 38 IS 4 BP 349 EP 352 PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA 218TH UT WOS:000081567400009 ER PT J AU Sukenik, A Schneider, JC Roessler, PG Livne, A Berner, T Kolber, Z Wyman, K Prasil, O Falkowski, PG AF Sukenik, A Schneider, JC Roessler, PG Livne, A Berner, T Kolber, Z Wyman, K Prasil, O Falkowski, PG TI Photosynthetic characterization of a mutant of Nannochloropsis deficient in the synthesis of eicosapentaenoic acid SO ISRAEL JOURNAL OF PLANT SCIENCES LA English DT Article ID MEMBRANE-LIPIDS; LIGHT; PHYTOPLANKTON; EUSTIGMATOPHYTE; IRRADIANCE; ACCLIMATION; TEMPERATURE; CHLORELLA; STABILITY; ALGAE AB Photosynthetic performance of an eicosapentaenoic acid (EPA; 20:5 omega 3) deficient mutant of the eustigmatophyte Nannochloropsis sp. was compared to the wild type (Wt) strain in order to evaluate the effect of fatty acid composition on the function of the photosynthetic apparatus. Cellular photosynthetic capacity and the cellular pool of pigments and of reaction centers were reduced in the mutant concomitant with a reduction in the amount of thylakoid membranes and their volume-specific density. Despite the changes observed in photosynthetic activity, the fluorescence properties of the mutant were virtually the same as those of the wild type, although the phase transition of thylakoid membrane was recorded at higher temperature in the mutant than in the Wt. The results suggest that the change in one double bond in a very long chain fatty acid of the thylakoid lipids plays a minor role in regulating photosynthetic electron transport, but that the mutation modified the ability of the mutant to acclimate to low-irradiance conditions. C1 Natl Inst Oceanog, Israel Oceanog & Limnol Res, IL-31080 Haifa, Israel. Natl Renewable Energy Lab, Appl Biol Sci Branch, Golden, CO 80401 USA. Bar Ilan Univ, Dept Life Sci, IL-52900 Ramat Gan, Israel. Brookhaven Natl Lab, Div Oceanog & Atmospher Sci, Environm Biophys & Mol Biol Program, Upton, NY 11973 USA. RP Sukenik, A (reprint author), Natl Inst Oceanog, Israel Oceanog & Limnol Res, POB 8030, IL-31080 Haifa, Israel. RI Prasil, Ondrej/H-2454-2014 OI Prasil, Ondrej/0000-0002-0012-4359 NR 26 TC 2 Z9 2 U1 0 U2 4 PU LASER PAGES PUBL LTD PI JERUSALEM PA MERKAZ SAPIR 6/37, GIVAT SHAUL PO BOX 35409, JERUSALEM 91352, ISRAEL SN 0792-9978 J9 ISRAEL J PLANT SCI JI Isr. J. Plant Sci. PY 1998 VL 46 IS 2 BP 101 EP 108 PG 8 WC Plant Sciences SC Plant Sciences GA 120RA UT WOS:000075969100006 ER PT B AU Benson, DA Bowman, D Filter, W Mitchell, R Perry, J AF Benson, DA Bowman, D Filter, W Mitchell, R Perry, J BE Bhavnani, SH Kromann, GB Nelson, DJ TI Design and characterization of microscale heater structures for test die and sensor applications SO ITHERM '98: SIXTH INTERSOCIETY CONFERENCE ON THERMAL AND THERMOMECHANICAL PHENOMENA IN ELECTRONIC SYSTEMS LA English DT Proceedings Paper CT 6th Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems CY MAY 27-30, 1998 CL SEATTLE, WA SP Components, Packaging & Mfg Technol, Inst Elect & Electr Engn, Amer Soc Mech Engn, Heat Transfer Div, Heat Transfer Electron EquipementComm (K-16), US Natl Inst Stand & Technol, Int Microelectron & Packaging Soc AB We describe a class of microscale healers fabricated with CMOS processes on silicon wafers. These heaters were designed to produce localized high temperatures above 400 degrees C for test and sensor applications. The temperature levels produced for various input powers and die thermal profiles surrounding the hearer for packaged and wafer-level hearer structures were studied to guide the placement of microelectronics integrated with the heater structures on the same die. To show the performance of the design, we present resistance sensor measurements, IR temperature profiles, and results from a 3D thermal model of the die. This effort demonstrates that it is possible to successfully operate both a microscale heater and microcircuits on the same die. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Benson, DA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4475-8 PY 1998 BP 434 EP 441 DI 10.1109/ITHERM.1998.689598 PG 8 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic; Engineering, Mechanical SC Computer Science; Engineering GA BL36J UT WOS:000075283400062 ER PT J AU Simmons-Potter, K Potter, B Sinclair, M AF Simmons-Potter, K Potter, B Sinclair, M TI Photosensitive thin films: Manipulation of defects through synthesis control SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS LA English DT Article; Proceedings Paper CT International Workshop on Structure and Functional Optical Properties of Silica and Silica-Related Glasses CY JUL 10-11, 1997 CL TOYOTA MOTOR CORP, MIKKABI CREAT CTR, SHIZUOKA, JAPAN SP US Govt HO TOYOTA MOTOR CORP, MIKKABI CREAT CTR DE photosensitivity; defects; germanosilicate; rf-sputtering; thin film ID GLASS-FILMS; SIO2-GEO2 GLASSES; WAVE-GUIDES; FIBERS; BAND; CENTERS AB Multi-functional, integrated optical devices are the foundation for technologies commanding a significant high-tech market share. Areas such as telecommunications, remote sensing, biomedical applications, information processing and data storage benefit from devices based on the patterning of refractive index modulations. Current synthesis techniques used to achieve the desired device structures typically involve multi-step processing, relying on complex chemical and/or mechanical procedures. We have demonstrated the ability to produce highly photosensitive germanosilicate thin films using a novel sputtering approach which enables us to obtain the largest reported Delta n in as-synthesized materials. In addition, control of processing environment has allowed us to engineer not only the magnitude of the optical response of the films but also the sign of the induced index change. We have developed a defect model to describe the effects observed and have demonstrated proof-of-principle devices in our waveguides. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Simmons-Potter, K (reprint author), Sandia Natl Labs, POB 5800,MS 1423, Albuquerque, NM 87185 USA. NR 16 TC 8 Z9 8 U1 0 U2 0 PU JAPAN SOC APPLIED PHYSICS PI TOKYO PA KUDAN-KITA BUILDING 5TH FLOOR, 1-12-3 KUDAN-KITA, CHIYODA-KU, TOKYO, 102-0073, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 1 JI Jpn. J. Appl. Phys. Part 1 - Regul. Pap. Brief Commun. Rev. Pap. PY 1998 VL 37 SU 1 BP 8 EP 11 PG 4 WC Physics, Applied SC Physics GA ZP235 UT WOS:000073731500004 ER PT B AU Samuel, MA AF Samuel, MA BE Hsu, JP Hsu, L TI The QCD coupling constant from tau decays SO JINGSHIN THEORETICAL PHYSICS SYMPOSIUM IN HONOR OF PROFESSOR TA-YOU WU LA English DT Proceedings Paper CT JingShin Theoretical Physics Symposium in Honor of Professor Ta-You Wu CY SEP, 1997 CL UNIV MASSACHUSETTS, DARTMOUTH, MA SP Jing Shin Res Fund, Univ Massachusetts, Dept Phys, Potz Sci Fund HO UNIV MASSACHUSETTS AB We suggest that naive perturbation theory up to 0(alpha(s)(3)) underestimates the theoretical prediction for R-tau = Gamma[tau(-) --> nu(tau) + hadrons]/Gamma[tau(-) --> nu(tau)e-<(nu)over bar>(e)]. We use Pade Summation (PS) and find alpha(s)(M-z) = .313 (9). Using the new 4-loop QCD beta-function, we find alpha(s)(M-z) = .1172 (11) in agreement with recent values. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Samuel, MA (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3372-8 PY 1998 BP 353 EP 361 PG 9 WC Physics, Atomic, Molecular & Chemical; Physics, Multidisciplinary; Physics, Condensed Matter; Physics, Particles & Fields; Physics, Mathematical SC Physics GA BL71B UT WOS:000076417900024 ER PT B AU Rocha, LM AF Rocha, LM GP IEEE TI Syntactic autonomy SO JOINT CONFERENCE ON THE SCIENCE AND TECHNOLOGY OF INTELLIGENT SYSTEMS LA English DT Proceedings Paper CT Joint Conference on the Science and Technology of Intelligent Systems ISIC/CIRA/ISAS CY SEP 14-17, 1998 CL NATL INST STAND & TECHNOL, GAITHERSBURG, MD SP IEEE, Control Syst Soc, Natl Sci Fdn, USA, Army Res Off HO NATL INST STAND & TECHNOL DE evolutionary systems; self-organization; autonomy; artificial life; semiotics; emergence; cellular automata; genetic algorithms; situated action AB The study of adapting and evolving autonomous agents should be based on a complex systems-theoretic framework which requires both self-organizing and symbolic dimensions. An inclusive framework based on the notions of semiotics and situated action is advanced to build models capable of representing, as well as evolving in their environments. Such undertaking is pursued by discussing the ways in which symbol and self-organization are irreducibly intertwined in evolutionary systems. This way, we re-think the notion of autonomy of evolving systems, and show that evolutionary systems are characterized by a particular type of syntactic autonomy. Recent developments in emergent computation in cellular automata are discussed as examples of the emergence of syntactic autonomy in computational environments. New results emphasizing this syntactic autonomy in cellular automata are presented. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Rocha, LM (reprint author), Univ Calif Los Alamos Natl Lab, MS P990, Los Alamos, NM 87545 USA. OI Rocha, Luis/0000-0001-9402-887X NR 0 TC 4 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4423-5 PY 1998 BP 706 EP 711 DI 10.1109/ISIC.1998.713806 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Automation & Control Systems; Computer Science GA BL60A UT WOS:000075973800124 ER PT B AU Joslyn, C AF Joslyn, C GP IEEE TI Models, controls, and levels of semiotic autonomy SO JOINT CONFERENCE ON THE SCIENCE AND TECHNOLOGY OF INTELLIGENT SYSTEMS LA English DT Proceedings Paper CT Joint Conference on the Science and Technology of Intelligent Systems ISIC/CIRA/ISAS CY SEP 14-17, 1998 CL NATL INST STAND & TECHNOL, GAITHERSBURG, MD SP IEEE, Control Syst Soc, Natl Sci Fdn, USA, Army Res Off HO NATL INST STAND & TECHNOL DE modeling; control; semiotics; autonomy AB In this paper we consider forms of autonomy, forms of semiotic systems, and any necessary relations among them. Levels of autonomy are identified as levels of system identity, from adiabatic closure to disintegration. Forms of autonomy or closure in systems are also recognized, including physical, dynamical, functional, and semiotic. Models and controls are canonical linear and circular (closed) semiotic relations respectively. We conclude that only at higher levels of autonomy do semiotic properties become necessary. In particular, all control systems display at least a minimal degree of semiotic autonomy; and all systems with sufficiently interesting functional autonomy are semiotically related to their environments. C1 Univ Calif Los Alamos Natl Lab, Comp & Informat Res Grp CIC3, Los Alamos, NM 87545 USA. RP Joslyn, C (reprint author), Univ Calif Los Alamos Natl Lab, Comp & Informat Res Grp CIC3, MS B265,LANL, Los Alamos, NM 87545 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4423-5 PY 1998 BP 747 EP 752 DI 10.1109/ISIC.1998.713813 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Automation & Control Systems; Computer Science GA BL60A UT WOS:000075973800131 ER PT J AU Fowler, JS Volkow, ND Wang, GJ Pappas, N Logan, J MacGregor, R Alexoff, D Wolf, AP Warner, D Cilento, R Zezulkova, I AF Fowler, JS Volkow, ND Wang, GJ Pappas, N Logan, J MacGregor, R Alexoff, D Wolf, AP Warner, D Cilento, R Zezulkova, I TI Neuropharmacological actions of cigarette smoke: Brain monoamine oxidase B (MAO B) inhibition SO JOURNAL OF ADDICTIVE DISEASES LA English DT Article ID POSITRON EMISSION TOMOGRAPHY; PARKINSONS-DISEASE; ADDICTIVE DRUGS; L-DEPRENYL; DOPAMINE; CESSATION; NICOTINE; TOBACCO; BINDING; HEAVY AB We measured the concentration of brain monoamine oxidase B (MAO B; EC 1.4.3.4) in 8 smokers and compared it with that in 8 non-smokers and in 4 former smokers using positron emission tomography (PET) and deuterium substituted [C-11]l-deprenyl ([C-11]L-deprenyl-D2) as a radiotracer for MAO B. Smokers had significantly lower brain MAO B than non-smokers as measured by the model term lambda k(3) which is a function of MAO B activity. Reductions were observed in all brain regions. Low brain MAO B in the cigarette smoker appears to be a pharmacological rather than a genetic effect since former smokers did not differ from non-smokers. Brain MAO B inhibition by cigarette smoke is of relevance in light of the inverse association between smoking and Parkinson's disease and a high prevalence of smoking in psychiatric disorders and in substance abuse. Though nicotine is at the core of the neuropharmacological actions of tobacco smoke, MAO B inhibition may also be an important variable in understanding and treating tobacco smoke addiction. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. RP Fowler, JS (reprint author), Brookhaven Natl Lab, Dept Chem & Med, Upton, NY 11973 USA. FU NIDA NIH HHS [DA 06891]; NINDS NIH HHS [NS 15380] NR 39 TC 76 Z9 79 U1 0 U2 3 PU HAWORTH PRESS INC PI BINGHAMTON PA 10 ALICE ST, BINGHAMTON, NY 13904-1580 USA SN 1055-0887 J9 J ADDICT DIS JI J. Addict. Dis. PY 1998 VL 17 IS 1 BP 23 EP 34 PG 12 WC Substance Abuse SC Substance Abuse GA ZD420 UT WOS:000072683400003 PM 9549600 ER PT J AU Goldberg, LA Goldberg, PW Phillips, CA Sorkin, GB AF Goldberg, LA Goldberg, PW Phillips, CA Sorkin, GB TI Constructing computer virus phylogenies SO JOURNAL OF ALGORITHMS LA English DT Article ID TREES AB There has been much recent algorithmic work on the problem of reconstructing the evolutionary history of biological species. Computer virus specialists are interested in finding the evolutionary history of computer viruses-a virus is often written using code fragments from one or more other viruses, which are its immediate ancestors. A phylogeny for a collection of computer viruses is a directed acyclic graph whose nodes are the viruses and whose edges map ancestors to descendants and satisfy the property that each code fragment is "invented" only once. To provide a simple explanation for the data, we consider the problem of constructing such a phylogeny with a minimum number of edges. This optimization problem is NP-hard, and we present positive and negative results for associated approximation problems. When tree solutions exist, they can be constructed and randomly sampled in polynomial time. (C) 1998 Academic Press. C1 Univ Warwick, Coventry CV4 7AL, W Midlands, England. Sandia Natl Labs, Albuquerque, NM 87185 USA. IBM Corp, Thomas J Watson Res Ctr, Yorktown Heights, NY 10598 USA. RP Goldberg, LA (reprint author), Univ Warwick, Coventry CV4 7AL, W Midlands, England. NR 20 TC 12 Z9 13 U1 1 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0196-6774 J9 J ALGORITHM JI J. Algorithms PD JAN PY 1998 VL 26 IS 1 BP 188 EP 208 DI 10.1006/jagm.1997.0897 PG 21 WC Computer Science, Theory & Methods; Mathematics, Applied; Logic SC Computer Science; Mathematics; Science & Technology - Other Topics GA YQ071 UT WOS:000071344600008 ER PT J AU Gao, W Coulter, RL Lesht, BM Qiu, J Wesely, ML AF Gao, W Coulter, RL Lesht, BM Qiu, J Wesely, ML TI Estimating clear-sky regional surface fluxes in the southern great plains atmospheric radiation measurement site with ground measurements and satellite observations SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID LAND-SURFACE; VEGETATION INDEXES; HEAT-FLUX; TALLGRASS PRAIRIE; SPECTRAL DATA; CONDUCTANCE; TEMPERATURE; ROUGHNESS; EXCHANGE; MODELS AB The authors compared methods for estimating surface fluxes under clear-sky conditions over a large heterogeneous area from a limited number of ground measurements and from satellite observations using data obtained from the southern Great Plains Cloud and Radiation Testbed (CART) site, an area of approximately 350 km x 400 km located in Kansas and Oklahoma. In situ measurements from 10 energy balance Bowen ratio (EBBR) stations showed large spatial variations in latent and sensible heat fluxes across the site because of differences in vegetation and soil conditions. This variation was reproduced by a model for parameterization of subgrid-scale (PASS) surface fluxes that was developed previously and extended in the present study to include a distribution of soil moisture inferred from combined visible and thermal infrared remote sensing data. In the framework of the PASS model, the satellite-derived normalized difference vegetation index and surface temperature were used to derive essential surface parameters including surface albedo, surface conductance, soil heat flux ratio, surface roughness length, and soil moisture, which were then used to calculate a surface energy budget at satellite-pixel scales with pixel-specific surface meteorological conditions appropriately distributed from their mean values using a distribution algorithm. Although the derived soil moisture may be influenced by various uncertainty factors involved in the satellite data and the model, spatial variations of soil moisture derived from the multichannel data from the Advanced Very High Resolution Radiometers on the NOAA-14 satellite appeared to have some correlation (the correlation coefficient is as large as 0.6) with the amount of accumulated previous rainfall measured at the 58 Oklahoma Mesonet stations located within the CART area. Surface net radiation, soil heat flux, and latent and sensible heat fluxes calculated at a spatial resolution of 1 km (the size of a satellite pixel) Were evaluated directly by comparing with flux measurements from the EBBR stations and indirectly by comparing air temperature and humidity inferred from calculated sensible and latent heat fluxes with corresponding values measured at 1.5 m above the 58 meteorological stations. In calculating regional fluxes, biases caused by the sampling uncertainty associated with point measurements may be corrected by application of the satellite data. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Gao, W (reprint author), Argonne Natl Lab, Div Environm Res, Bldg 203,Rm J159,9700 S Cass Ave, Argonne, IL 60439 USA. NR 32 TC 40 Z9 41 U1 1 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD JAN PY 1998 VL 37 IS 1 BP 5 EP 22 DI 10.1175/1520-0450(1998)037<0005:ECSRSF>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YQ932 UT WOS:000071439100002 ER PT J AU Zhang, Y Mascarenhas, A Jones, ED AF Zhang, Y Mascarenhas, A Jones, ED TI Magnetoexcitons in anisotropic semiconductors SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MAGNETIC-FIELD; ENERGY-LEVELS; GROUND-STATE; EXCITON; CRYSTALS; MASSES AB Using a numerical technique, we have calculated the exciton ground state in a uniaxially anisotropic semiconductor with and without the presence of a magnetic field. Numerical results are given for the exciton energy level as a function of magnetic field for a wide range of anisotropy parameters 0.001 less than or equal to alpha beta less than or equal to 1000 and effective field 0 less than or equal to gamma less than or equal to 10. We have demonstrated that by fitting the experimental data of the field dependence, in a proper field range, with the field aligned in the direction of the uniaxis, the exciton in plane reduced mass mu(perpendicular to), and the parameter alpha beta can be obtained simultaneously. As an example, magnetoluminescence of ordered GaInP2 measured in the field range B less than or equal to 14 T is analyzed by applying this method. Analytical formulas have been found for calculating exciton binding energy and the related variational parameters for a well-known method with trial function f(x,y,z)=(pi a(2)b)(-1) exp[-root(x(2)+y(2))/a(2)+z(2)/b(2)]. Various approximate approaches for calculating the exciton binding energy and the magnetoexciton states are discussed and compared. (C) 1998 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Zhang, Y (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 30 TC 18 Z9 18 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 1 PY 1998 VL 83 IS 1 BP 448 EP 454 DI 10.1063/1.366659 PG 7 WC Physics, Applied SC Physics GA YP836 UT WOS:000071320400065 ER PT J AU Shan, W Fischer, AJ Hwang, SJ Little, BD Hauenstein, RJ Xie, XC Song, JJ Kim, SS Goldenberg, B Horning, R Krishnankutty, S Perry, WG Bremser, MD Davis, RF AF Shan, W Fischer, AJ Hwang, SJ Little, BD Hauenstein, RJ Xie, XC Song, JJ Kim, SS Goldenberg, B Horning, R Krishnankutty, S Perry, WG Bremser, MD Davis, RF TI Intrinsic exciton transitions in GaN SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID OPTICAL-PROPERTIES; GALLIUM NITRIDE; LAYERS; EPILAYERS; SAPPHIRE; STRAIN; FILMS AB Intrinsic excitonic transitions in GaN have been studied using a variety of spectroscopic measurements. Sharp spectral structures associated with intrinsic free excitons could be observed in photoluminescence, reflection, and absorption spectra. The energy positions of excitonic transitions in GaN epitaxial layers were found to be influenced by the residual strain resulting from lattice-parameter and thermal-expansion mismatches between the epilayers and the substrates. The values of the four principal deformation potentials of wurtzite GaN were derived by using the strain tensor components determined by x-ray measurements, The observation of spectral features involving the emission of LO phonons in absorption and photoluminescence excitation spectra at energies above exciton resonances indicate that a phonon-assisted indirect excitation process, which simultaneously generates a free exciton and a LO phonon, is a very significant and efficient process in GaN. The lifetime of the free excitons is found to be longer than the relaxation time of LO-phonon emission but much shorter than that of acoustic-phonon emission. (C) 1998 American Institute of Physics. C1 Oklahoma State Univ, Ctr Laser & Photon Res, Stillwater, OK 74078 USA. Oklahoma State Univ, Dept Phys, Stillwater, OK 74078 USA. Seoul Natl Univ, Dept Phys, Seoul 151742, South Korea. Honeywell Technol Ctr, Plymouth, MN 55441 USA. N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. RP Shan, W (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Davis, Robert/A-9376-2011 OI Davis, Robert/0000-0002-4437-0885 NR 35 TC 40 Z9 41 U1 2 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 1 PY 1998 VL 83 IS 1 BP 455 EP 461 DI 10.1063/1.366660 PG 7 WC Physics, Applied SC Physics GA YP836 UT WOS:000071320400066 ER PT J AU Zhou, D McCauley, TG Qin, LC Krauss, AR Gruen, DM AF Zhou, D McCauley, TG Qin, LC Krauss, AR Gruen, DM TI Synthesis of nanocrystalline diamond thin films from an Ar-CH4 microwave plasma SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CHEMICAL VAPOR-DEPOSITION; GROWTH; HYDROGEN; OXYGEN; ARGON AB Nanocrystalline diamond thin films have been synthesized in an Ar-CH4 microwave discharge, without the addition of molecular hydrogen. X-ray diffraction, transmission electron microscopy, and electron energy loss spectroscopy characterizations show that the films consist of a pure crystalline diamond phase with very small grain sizes ranging from 3 to 20 nm. Atomic force microscopy analysis demonstrates that the surfaces of the nanocrystalline diamond films remain smooth independent of the film thicknesses. Furthermore, the reactant gas pressure, which strongly affects the concentration of C-2 dimer in the Ar-CH4 plasma as well as the growth rate of the films, has been found to be a key parameter for the nanocrystalline diamond thin film depositions. (C) 1998 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Zhou, D (reprint author), Univ Cent Florida, Dept Mech Mat & Aerosp Engn, Adv Mat Proc & Anal Ctr, Orlando, FL 32816 USA. NR 22 TC 189 Z9 193 U1 3 U2 20 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 1 PY 1998 VL 83 IS 1 BP 540 EP 543 DI 10.1063/1.366668 PG 4 WC Physics, Applied SC Physics GA YP836 UT WOS:000071320400080 ER PT J AU Luysberg, M Sohn, H Prasad, A Specht, P Liliental-Weber, Z Weber, ER Gebauer, J Krause-Rehberg, R AF Luysberg, M Sohn, H Prasad, A Specht, P Liliental-Weber, Z Weber, ER Gebauer, J Krause-Rehberg, R TI Effects of the growth temperature and As/Ga flux ratio on the incorporation of excess As into low temperature grown GaAs SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; DEPENDENCE; LAYERS AB The controlled incorporation of excess As into GaAs grown by molecular beam epitaxy at low growth temperatures (LT-GaAs) is explored. The substrate temperature and the As/Ga flux ratio were systematically varied to investigate the influence of growth parameters on the formation of native defects and structural properties. Near infrared absorption, magnetic circular dichroism of absorption, and slow positron annihilation were applied to determine point defect concentrations of As antisites (As(Ga)) and Ga vacancies (V(Ga)) Structural properties of as-grown and annealed LT-GaAs layers were investigated by x-ray diffraction and transmission electron microscopy. In a well defined parameter range the lattice expansion of the LT-GaAs layers correlates with the amount of As(Ga) The V(Ga) acceptor concentration can quantitatively account for the ionization of the As(Ga) donors. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Halle Wittenberg, D-4010 Halle, Germany. RP Luysberg, M (reprint author), Forschungszentrum Julich, Inst Festkorperforsch, D-52425 Julich, Germany. EM m.luysberg@fz-juelich.de RI Liliental-Weber, Zuzanna/H-8006-2012; Kim, youngjae/I-7780-2012; Luysberg, Martina/B-6448-2014 OI Luysberg, Martina/0000-0002-5613-7570 NR 19 TC 91 Z9 91 U1 3 U2 19 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 1 PY 1998 VL 83 IS 1 BP 561 EP 566 DI 10.1063/1.366723 PG 6 WC Physics, Applied SC Physics GA YP836 UT WOS:000071320400083 ER PT J AU Draney, ML AF Draney, ML TI Sougambus georgiensis Chamberlin & Ivie, a junior synonym of Goneatara platyrhinus (Crosby & Bishop) (Araneae, Linyphiidae, Erigoninae) SO JOURNAL OF ARACHNOLOGY LA English DT Article C1 Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Draney, ML (reprint author), Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER ARACHNOLOGICAL SOC PI NEW YORK PA C/O NORMAN I PLATNICK, AMER MUSEUM NATURAL HISTORY, CENTRAL PK WEST AT 79TH ST, NEW YORK, NY 10024 USA SN 0161-8202 J9 J ARACHNOL JI J. Arachnol. PY 1998 VL 26 IS 2 BP 247 EP 248 PG 2 WC Entomology SC Entomology GA 134UB UT WOS:000076761000011 ER PT J AU Small, W Heredia, NJ Maitland, DJ Eder, DC Celliers, PM Da Silva, LB London, RA Matthews, DL AF Small, Ward Heredia, Nicholas J. Maitland, Duncan J. Eder, David C. Celliers, Peter M. Da Silva, Luiz B. London, Richard A. Matthews, Dennis L. TI EXPERIMENTAL AND COMPUTATIONAL LASER TISSUE WELDING USING A PROTEIN PATCH SO JOURNAL OF BIOMEDICAL OPTICS LA English DT Article DE collagen; infrared thermometry; modeling; surface temperature; tissue fusion AB An in vitro study of laser tissue welding mediated with a dye-enhanced protein patch was conducted. Fresh sections of porcine aorta were used for the experiments. Arteriotomies were treated using an indocyanine green dye-enhanced collagen patch activated by an 805-nm continuous-wave fiber-delivered diode laser. Temperature histories of the surface of the weld site were obtained using a hollow glass optical fiber- based two-color infrared thermometer. The experimental effort was complemented by simulations with the LATIS (LAser-TISsue) computer code, which uses coupled Monte Carlo, thermal transport, and mass transport models. Comparison of simulated and experimental thermal data indicated that evaporative cooling clamped the surface temperature of the weld site below 100 degrees C. For fluences of approximately 200 J/cm(2), peak surface temperatures averaged 74 degrees C and acute burst strengths consistently exceeded 0.14x10(6) dyn/cm ( hoop tension). The combination of experimental and simulation results showed that the inclusion of water transport and evaporative losses in the computer code has a significant impact on the thermal distributions and hydration levels throughout the tissue volume. The solid-matrix protein patch provided a means of controllable energy delivery and yielded consistently strong welds. (C) 1998 Society of Photo-Optical Instrumentation Engineers. C1 [Small, Ward; Heredia, Nicholas J.; Maitland, Duncan J.; Eder, David C.; Celliers, Peter M.; Da Silva, Luiz B.; London, Richard A.; Matthews, Dennis L.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Small, W (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM small3@llnl.gov FU U.S. Department of Energy by Lawrence Livermore National Laboratory, Cooperative Research and Development with Conversion Energy Enterprises of Spring Valley, New York [W-7405-ENG-48, TC-1085-95] FX This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract W-7405-ENG-48 as part of the Cooperative Research and Development Agreement TC-1085-95 with Conversion Energy Enterprises of Spring Valley, New York. The authors wish to thank J. Harrington for providing the hollow glass fiber, and J. Cox and K. Haney for their help in fabricating the experimental apparatus. NR 15 TC 5 Z9 5 U1 2 U2 2 PU SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 1083-3668 EI 1560-2281 J9 J BIOMED OPT JI J. Biomed. Opt. PD JAN PY 1998 VL 3 IS 1 BP 96 EP 101 DI 10.1117/1.429866 PG 6 WC Biochemical Research Methods; Optics; Radiology, Nuclear Medicine & Medical Imaging SC Biochemistry & Molecular Biology; Optics; Radiology, Nuclear Medicine & Medical Imaging GA V32RH UT WOS:000208967800013 PM 23015011 ER PT J AU Reardon, J Datye, AK Sault, AG AF Reardon, J Datye, AK Sault, AG TI Tailoring alumina surface chemistry for efficient use of supported MoS2 SO JOURNAL OF CATALYSIS LA English DT Article ID RESOLUTION ELECTRON-MICROSCOPY; X-RAY PHOTOELECTRON; HYDROTREATING CATALYSTS; MORPHOLOGY; MOLYBDENA; SPECTROSCOPY; HYDRODESULFURIZATION; DESORPTION; ADSORPTION; DIOXIDE AB Reported activity trends for hydrodesulfurization (HDS) over MoS2/gamma-Al2O3 catalysts show a maximum in activity with Mo loading when activity is normalized to Mo content. In contrast, simple monotonic decreases in normalized activity are observed over TiO2 and ZrO2 supports. While earlier work ascribes these different activity trends to differences in MoS2 morphology, activity measurements and transmission electron microscope images presented here conclusively demonstrate that the two different trends can occur on support materials that give rise to virtually identical MoS2 morphologies. Since differences in morphology cannot explain this result, we instead propose the following chemical explanation involving the formation of inactive molybdate species on gamma-Al2O3 at low Mo coverages. Reaction of aqueous molybdates with the highest frequency, or type I-a, OH groups on gamma-Al2O3 is known to form stable MoO42- species at low Mo coverages, which are difficult to convert into the active MoS2 form. As a result, normalized HDS activity is very low As Mo coverage increases the type I-a OH groups are consumed and formation of more easily sulfided molybdate species begins to predominate, and normalized activity increases. Ultimately, normalized activity goes through a maximum with Mo coverage as the average size of the MoS2 platelets begins to grow, resulting in a decrease in the fraction of Mo atoms located at active edge sites. Since the type-I-a hydroxyls on gamma-Al2O3 are associated with tetrahedrally coordinated Al cations, it should be possible to prevent the formation of inactive molybdates, and thereby eliminate the maximum in activity with coverage, by removing all tetrahedrally coordinated Al cations from the surface. This removal has been accomplished through the use of alpha-Al2O3, which contains only octahedrally coordinated Al atoms, and through titration of the type I-a hydroxyls on gamma-Al2O3 with titanium isopropoxide prior to Mo loading. In both cases, no maximum in activity is observed and activity at all Mo loadings is higher than on gamma-Al2O3 Fourier transform infrared measurements of OH group consumption coupled with X-ray photoelectron spectroscopy measurements of molybdate reducibility support the chemical explanation by demonstrating that reaction of gamma-Al2O3 with titanium isopropoxide preferentially consumes type I-a hydroxyls and that molybdates are more easily reduced on alpha-Al2O3 and titania coated gamma-Al2O3 than on pure gamma-Al2O3. Thus, titration of type I-a OH groups on gamma-alumina by a suitable modifier, such as titania, offers a simple method for increasing the overall activity of supported MoS2 catalysts, while retaining the advantageous properties of gamma-Al2O3 supports, such as high surface area and thermal stability. (C) 1998 Academic Press. C1 Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. Sandia Natl Labs, Catalysis & Chem Technol Dept, Albuquerque, NM 87185 USA. RP Sault, AG (reprint author), Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. OI Datye, Abhaya/0000-0002-7126-8659 NR 35 TC 19 Z9 19 U1 0 U2 7 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9517 J9 J CATAL JI J. Catal. PD JAN 1 PY 1998 VL 173 IS 1 BP 145 EP 156 DI 10.1006/jcat.1997.1874 PG 12 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA YV439 UT WOS:000071824200015 ER PT J AU Bradbury, EM AF Bradbury, EM TI Nucleosome and chromatin structures and functions SO JOURNAL OF CELLULAR BIOCHEMISTRY LA English DT Article DE nucleosome; chromosomes; DNA ID GLOBULAR DOMAIN; LINKER HISTONES; MOLECULAR-BASIS; CELL-DIVISION; DNA; PHOSPHORYLATION; RESOLUTION; MITOSIS; MODEL; SITES C1 Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. Univ Calif Lawrence Livermore Natl Lab, Dept Biol Chem, Sch Med, Livermore, CA 95616 USA. RP Bradbury, EM (reprint author), Univ Calif Los Alamos Natl Lab, Div Life Sci, Mail Stop M888, Los Alamos, NM 87545 USA. NR 39 TC 2 Z9 2 U1 1 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0730-2312 J9 J CELL BIOCHEM JI J. Cell. Biochem. PY 1998 SU 30-31 BP 177 EP 184 PG 8 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 154ZV UT WOS:000077921800022 ER PT J AU Lelievre, SA Bissell, MJ AF Lelievre, SA Bissell, MJ TI Communication between the cell membrane and the nucleus: Role of protein compartmentalization SO JOURNAL OF CELLULAR BIOCHEMISTRY LA English DT Review DE signal transduction; cell adhesion complexes; membrane skeleton; nucleo-cytoplasmic translocation ID ABL TYROSINE KINASE; RECONSTITUTED BASEMENT-MEMBRANE; TRANSCRIPTION FACTOR LEF-1; MAMMARY EPITHELIAL-CELLS; TUMOR-SUPPRESSOR PROTEIN; CASEIN GENE-EXPRESSION; EXTRACELLULAR-MATRIX; BETA-CATENIN; SIGNAL-TRANSDUCTION; AXIS SPECIFICATION AB Understanding how the information is conveyed from outside to inside the cell is a critical challenge for all biologists involved in signal transduction. The flow of information initiated by cell-cell and cell-extracellular matrix contacts is mediated by the formation of adhesion complexes involving multiple proteins. Inside adhesion complexes, connective membrane skeleton (CMS) proteins are signal transducers that bind to adhesion molecules, organize the cytoskeleton, and initiate biochemical cascades. Adhesion complex-mediated signal transduction ultimately directs the formation of supramolecular structures in the cell nucleus, as illustrated by the establishment of multi complexes of DNA-bound transcription factors, and the redistribution of nuclear structural proteins to form nuclear subdomains. Recently, several CMS proteins have been observed to travel to the cell nucleus, suggesting a distinctive role for these proteins in signal transduction. This review focuses on the nuclear translocation of structural signal transducers of the membrane skeleton and also extends our analysis to possible translocation of resident nuclear proteins to the membrane skeleton. This leads us to envision the communication between spatially distant cellular compartments (i.e., membrane skeleton and cell nucleus) as a bidirectional flow of information (a dynamic reciprocity) based on subtle multilevel structural and biochemical equilibria. At one level, it is mediated by the interaction between structural signal transducers and their binding partners, at another level it may be mediated by the balance and integration of signal transducers in different cellular compartments. (C) 1998 Wiley-iiss, Inc. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Lelievre, SA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, MS 83-101,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM slelievre@lbl.gov NR 140 TC 3 Z9 3 U1 1 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0730-2312 J9 J CELL BIOCHEM JI J. Cell. Biochem. PY 1998 SU 30-31 BP 250 EP + PG 17 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 154ZV UT WOS:000077921800031 ER PT J AU Christian, JE Desjarlais, A Graves, R AF Christian, JE Desjarlais, A Graves, R TI Five-year field study confirms accelerated thermal aging method for polyisocyanurate insulation SO JOURNAL OF CELLULAR PLASTICS LA English DT Article; Proceedings Paper CT Polyurethanes World Congress 1995 CY SEP 26-29, 1995 CL CHICAGO, ILLINOIS AB In 1989, industry produced some experimental, permeably-faced polyisocyanurate (PIR) laminated board insulation blown with HCFC-141b and a second batch blown with CFC-11, which has undergone continuous field thermal performance monitoring for 5.5 years (June 1989 until February 1995). From these boards, several thin-sliced specimens were prepared and laboratory k-factors periodically measured on these core foam specimens. This work was conducted as part of a six-year joint research project between The Society of the Plastics Industry, Inc. (SPI). Polyisocyanurate Insulation Manufacturers Association (PIMA), National Roofing Contractors Association (NRCA), and the U.S. Department of Energy (DOE) Oak Ridge National Laboratory (ORNL). One of the major research products from this cooperative research effort was the development of an accelerated method for predicting full thickness lifetime thermal conductivities ("in-service R-values") of permeably-faced polyisocyanurate products. This paper compares the prediction of the field installed permeably-faced boards generated from the accelerated aging procedure to the actual measured field performance. The field applications consist of loose-laid boards under ethylene propylene diene terpolymer (EPDM) membranes in a low-sloped roof installed in the ORNL Roof Thermal Research Apparatus (RTRA). For the 5.5 years, each test roof was monitored hourly for temperature and heat flux. This data provides a time series of boundary conditions for a computer program PROPOR (Properties-Oak Ridge) to compute weekly thermal conductivities. PROPOR is an application of one-dimensional inverse heat transfer analysis. Every six months the test specimens were pulled from the roof and tested under steady state conditions in the laboratory according in American Society of Testing Materials (ASTM) C 518-91. This field validation of an accelerated aging procedure concludes that the thin slicing and laboratory k-factor measurements, within the first six months, accurately predict five years of full thickness, in-situ thermal performance of HCFC-141b permeably-faced polyisocyanurate insulation boards. A computer program was developed which uses the thin slice data set of a specific manufacturer's insulation. The design service life and full product thickness is input, and the in-service R-value is estimated. This value will vary depending on results from the thin slice testing. This work is leading toward an acceptable industry standard to determine the in-service R-value, which is defined as the design thermal resistance of insulation over the normal life of a roof system containing foams which thermally age. At the National Roof Contractors Association 110th Annual Convention Feb. 4, 1997 in Orlando, Florida, the Polyisocyanurate Insulation Manufacturers announced that by January 1, 1998 each PIMA member-insulation manufacturer would have available aged thermal performance data. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Natl Roofing Contractors Assoc, Rosemont, IL 60018 USA. RP Graves, R (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 30 TC 4 Z9 4 U1 0 U2 0 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0021-955X J9 J CELL PLAST JI J. Cell. Plast. PD JAN-FEB PY 1998 VL 34 IS 1 BP 39 EP + PG 28 WC Chemistry, Applied; Polymer Science SC Chemistry; Polymer Science GA YW525 UT WOS:000071945100002 ER PT J AU Stout, DB Huang, SC Melega, WP Raleigh, MJ Phelps, ME Barrio, JR AF Stout, DB Huang, SC Melega, WP Raleigh, MJ Phelps, ME Barrio, JR TI Effects of large neutral amino acid concentrations on 6-[F-18]fluoro-L-DOPA kinetics SO JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM LA English DT Article DE positron emission tomography; 6-[F-18]fluoro-L-DOPA; large neutral amino acids; non-human primate ID POSITRON EMISSION TOMOGRAPHY; BLOOD-BRAIN-BARRIER; PARKINSONS-DISEASE; L-DOPA; BIOCHEMICAL PARAMETERS; DECARBOXYLASE ACTIVITY; RHESUS-MONKEYS; TRANSPORT; MPTP; PET AB 6-[F-18]Fluoro-L-3,4-dihydroxyphenylalanine (FDOPA) has been used to measure the central dopaminergic function in many species, including humans and monkeys. For transport across the blood brain barrier (BBB), FDOPA competes with plasma large neutral amino acids (LNAA). In this article we evaluate the effects of normal physiological LNAA concentration variation on BBB transport (K1) and the FDOPA uptake measurement, Ki. We also investigate a method for reducing the dependency of FDOPA quantitation on LNAA. Adult vervet monkeys (Cercopithecus aethiops sabaeus, n = 19) were fasted overnight before FDOPA positron emission tomography scans. Blood samples were drawn for LNAA determination, metabolite analysis, and compartmental modeling. The estimated K1 and Ki were both negatively correlated with LNAA concentrations (r(2) = 0.51 and 0.62, respectively). Using an adjustment to K1 and Ki based on these correlations, the LNAA dependency was reduced (SD of the data for K1 was reduced by 33%, for Ki by 40%). Experiments with amino acid loading on an additional six animals indicate that BBB transport can be described using Michaelis-Menten kinetics. Results show a clear dependence of FDOPA uptake on plasma LNAA concentrations, which can be removed to increase the precision of FDOPA quantitation. C1 Univ Calif Los Angeles, Sch Med, Dept Med & Mol Pharmacol, Ctr Hlth Sci B2 086A, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Sch Med, Lab Struct Biol & Mol Med DOE, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Sch Med, Brain Res Inst, Los Angeles, CA 90095 USA. Sepulveda Vet Adm, Los Angeles, CA USA. RP Huang, SC (reprint author), Univ Calif Los Angeles, Sch Med, Dept Med & Mol Pharmacol, Ctr Hlth Sci B2 086A, Los Angeles, CA 90095 USA. FU NINDS NIH HHS [R01 NS 33356] NR 39 TC 37 Z9 37 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0271-678X J9 J CEREBR BLOOD F MET JI J. Cereb. Blood Flow Metab. PD JAN PY 1998 VL 18 IS 1 BP 43 EP 51 PG 9 WC Endocrinology & Metabolism; Hematology; Neurosciences SC Endocrinology & Metabolism; Hematology; Neurosciences & Neurology GA YN282 UT WOS:000071151300003 PM 9428304 ER PT J AU Seaborg, GT AF Seaborg, GT TI Viewpoints: Chemists on chemistry SO JOURNAL OF CHEMICAL EDUCATION LA English DT Editorial Material C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Lawrence Hall Sci, Berkeley, CA 94720 USA. RP Seaborg, GT (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Lawrence Hall Sci, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9584 J9 J CHEM EDUC JI J. Chem. Educ. PD JAN PY 1998 VL 75 IS 1 BP 13 EP 15 PG 3 WC Chemistry, Multidisciplinary; Education, Scientific Disciplines SC Chemistry; Education & Educational Research GA YM871 UT WOS:000071110000005 ER PT J AU Xantheas, SS Fanourgakis, GS Farantos, SC Velegrakis, M AF Xantheas, SS Fanourgakis, GS Farantos, SC Velegrakis, M TI Spectroscopic constants of the X (2)Sigma(+) and A (2)Pi states of Sr+Ar from first principles: Comparison with experiment SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; CONFIGURATION-INTERACTION CALCULATIONS; WAVE-FUNCTIONS; ATOMS; PAIRS; IONS AB We present the first nonempirically calculated spectroscopic constants for the recently observed [J. Chem. Phys. 105, 2167 (1996)] ground (X (2) Sigma(+)) and excited (A (2) Pi) states of Sr+Ar. Our best results yield D-e = 694 cm(-1), R-e = 3.662 Angstrom, and omega(e) = 38.7 cm(-1) for the ground and D-e = 1967 cm(-1), R-e = 3.169 Angstrom, and omega(e) = 99.1 cm(-1) for the excited state. The calculated D-e's are within the error bars of the experimentally determined one for the ground state favoring the low end and underestimate the corresponding one for the excited state by about 7% The equilibrium separations (R-e's) for the two states have not been experimentally determined, however our results accurately reproduce the estimated shift, Delta R-e, between the two states. The interaction is mainly electrostatic for the ground state for which the contribution of dynamic electron correlation was found to be more important than for the excited state. (C) 1997 American Institute of Physics. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Fdn Res & Technol Hellas, Inst Elect Struct & Laser, Iraklion 71110, Greece. Univ Crete, Dept Chem, Iraklion 71110, Crete, Greece. RP Xantheas, SS (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999,MS K1-96, Richland, WA 99352 USA. RI Velegrakis, Michalis/F-7810-2011; FARANTOS, STAVROS/H-5429-2011; Xantheas, Sotiris/L-1239-2015; OI FARANTOS, STAVROS/0000-0003-1909-7976; Xantheas, Sotiris/0000-0002-6303-1037 NR 25 TC 15 Z9 15 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 1 PY 1998 VL 108 IS 1 BP 46 EP 49 DI 10.1063/1.475363 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YP021 UT WOS:000071233300009 ER PT J AU Feller, D Peterson, KA AF Feller, D Peterson, KA TI An examination of intrinsic errors in electronic structure methods using the Environmental Molecular Sciences Laboratory computational results database and the Gaussian-2 set SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION CALCULATIONS; TOTAL ATOMIZATION ENERGIES; VIBRATION-ROTATION INTERACTION; HIGHER-DERIVATIVE METHODS; WAVE-FUNCTIONS; BENCHMARK CALCULATIONS; HARMONIC FREQUENCIES; SYSTEMATIC SEQUENCES; POLYATOMIC-MOLECULES; DISSOCIATION-ENERGY AB The Gaussian-2 (G2) collection of atoms and molecules has been studied with Hartree-Fock and correlated levels of theory, ranging from second-order perturbation theory to coupled cluster theory with noniterative inclusion of triple excitations. By exploiting the systematic convergence properties of the correlation consistent family of basis sets, complete basis set limits were estimated for a large number of the G2 energetic properties. Deviations with respect to experimentally derived energy differences corresponding to rigid molecules were obtained for 15 basis set/method combinations, as well as the estimated complete basis set limit. The latter values are necessary for establishing the intrinsic error for each method. In order to perform this analysis, the information generated in the present study was combined with the results of many previous benchmark studies in an electronic database, where it is available for use by other software tools. Such tools can assist users of electronic structure codes in making appropriate basis set and method choices that will increase the likelihood of achieving their accuracy goals without wasteful expenditures of computer resources. (C) 1998 American Institute of Physics. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Pacific NW Lab, Environm Mol Sci Lab, 906 Battelle Blvd,MS K1-96, Richland, WA 99352 USA. NR 69 TC 237 Z9 238 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 1 PY 1998 VL 108 IS 1 BP 154 EP 176 DI 10.1063/1.475370 PG 23 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YP021 UT WOS:000071233300019 ER PT J AU Bour, P Tam, CN Sopkova, J Trouw, FR AF Bour, P Tam, CN Sopkova, J Trouw, FR TI Measurement and ab initio modeling of the inelastic neutron scattering of solid N-methylformamide SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VIBRATIONAL OPTICAL-ACTIVITY; METHYLACETAMIDE; ABINITIO; DIFFRACTION; DYNAMICS; CANCER; AMIDES; PHASE; TRANS AB Vibrational motions of solid N-methylformamide (NMF) and its N-deuterated analogue are investigated using the inelastic neutron scattering (INS) technique at 15 K. The force field for obtaining the normal vibrational modes of the crystal is based on a quantum chemical calculation and a subsequent transfer of a harmonic force field of a smaller pentameric segment to a fragment of 11 NMF molecules. Two types of hydrogen bonds present in crystalline NMF are also modeled with dimers. The distinct bonding leads to a splitting of the N-hydrogen wagging mode in the spectrum. Although the hydrogen bonding has a profound effect on vibrational frequencies, the results indicate that an occurrence of a double-well potential for bonded hydrogen proposed previously is unlikely. Instead, a limited electronic conjugation along the hydrogen bonds in crystalline NMF is observed. Unlike in previous models, we simulate the relative INS intensity of each vibrational transition separately, which leads to a substantial improvement of the overall profile of the intensity pattern. The modeling allows one to assign most of observed INS bands to vibrational modes and the overall spectral profile that reproduced by the simulation compares well with the experiment. (C) 1998 American Institute of Physics. C1 Acad Sci Czech Republic, Inst Organ Chem & Biochem, CR-16610 Prague, Czech Republic. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Bour, P (reprint author), Acad Sci Czech Republic, Inst Organ Chem & Biochem, Flemingovo Nam 2, CR-16610 Prague, Czech Republic. RI Bour, Petr/G-5561-2014; Sopkova-de Oliveira , Jana/L-2891-2015 NR 32 TC 34 Z9 34 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 1 PY 1998 VL 108 IS 1 BP 351 EP 358 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YP021 UT WOS:000071233300037 ER PT J AU Ally, MR Braunstein, J AF Ally, MR Braunstein, J TI Statistical mechanics of multilayer adsorption: electrolyte and water activities in concentrated solutions SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE aqueous electrolytes; activities; thermodynamics; adsorption ID DEW-POINT APPARATUS; VAPOR-PRESSURES; ACTIVITY-COEFFICIENTS; AQUEOUS-SOLUTIONS; BET MODEL AB Approximately 33 years after Stokes and Robinson's modification of the Brunauer-Emmett-Teller (BET) adsorption isotherm paved the way for experimental investigations of the water activities and properties of concentrated aqueous electrolytes, Abraham derived an equation giving the activity of a salt on the basis of the same model, but restricted his result to a binary aqueous system consisting of one salt only. Many investigators have used Stokes and Robinson's modification to show good agreement between experimental and calculated water activities even for ternary and quaternary aqueous solutions, if the system is treated as a pseudobinary. However, no previous (theoretical) attempt has been made to go beyond the single salt or pseudobinary restriction of Abraham. In this paper, we categorically prove that there is no fundamental limitation that restricts the BET model to a single electrolyte. We verify the consistency of our results through satisfaction of the Gibbs-Duhem relationships and by showing agreement between the calculated and experimental data of Iyoki on water vapor pressures for {x(2.8LiCl + LiNO3) + (1 - x)H2O}, where x = omega M-w/{omega M-w + (1 - omega)M-s}; omega denotes the mass fraction of lithium salts; and M-w and M-s denote the molar masses of H2O and of (2.8LiCl + LiNO3), respectively. In predicting activities of the components of {x(2.8LiCl + LiNO3) + (1 - x)H2O}, no experimental data on this ternary system are utilized. This fact underlies the predictive quality of the theoretical model presented in our paper. By induction, we extend our results to the case of (water + N electrolytes). (C) 1998 Academic Press Limited. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Ally, MR (reprint author), Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. NR 17 TC 47 Z9 48 U1 5 U2 13 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD JAN PY 1998 VL 30 IS 1 BP 49 EP 58 DI 10.1006/jcht.1997.0278 PG 10 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA YZ291 UT WOS:000072239700007 ER PT J AU Krumke, SO Marathe, MV Noltemeier, H Ravi, R Ravi, SS AF Krumke, SO Marathe, MV Noltemeier, H Ravi, R Ravi, SS TI Approximation algorithms for certain network improvement problems SO JOURNAL OF COMBINATORIAL OPTIMIZATION LA English DT Article DE complexity; NP-hardness; approximation algorithms ID GRAPHS; TIME AB We study budget constrained,network upgrading problems. Such problems aim at finding optimal strategies for improving a network under some cost measure subject to certain budget constraints. Given an edge weighted graph G = (V, E), in the edge based upgrading model, it is assumed that each edge e of the given network also has an associated function c(e)(t) that specifies the cost of upgrading the edge by an amount t. A reduction strategy specifies for each edge e the amount by which the length e(e) is to be reduced, In the node based upgrading model, a node v can be upgraded at an expense of c(v). Such an upgrade reduces the delay of each edge incident on v, For a given budget B, the goal is to find an improvement strategy such that the total cost of reduction is at most the given budget B and the cost of a subgraph (e,g. minimum spanning tree) under the modified edge lengths is the best over all possible strategies which obey the budget constraint. After providing a brief overview of the models and definitions of the various problems considered, we present several new results on the complexity and approximability of network improvement problems. C1 Konrad Zuse Zentrum Informationstechnik Berlin, Dept Org, D-14195 Berlin, Germany. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Wurzburg, Dept Comp Sci, D-97074 Wurzburg, Germany. Carnegie Mellon Univ, Grad Sch Ind Adm, Pittsburgh, PA 15213 USA. SUNY Albany, Dept Comp Sci, Albany, NY 12222 USA. RP Krumke, SO (reprint author), Konrad Zuse Zentrum Informationstechnik Berlin, Dept Org, Takustr 7, D-14195 Berlin, Germany. EM krumke@zib.de; madhav@lanl.gov; noltemei@informatik.uni-wuerzburg.de; ravi+@cmu.edu; ravi@cs.albany.edu NR 26 TC 26 Z9 28 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1382-6905 EI 1573-2886 J9 J COMB OPTIM JI J. Comb. Optim. PY 1998 VL 2 IS 3 BP 257 EP 288 DI 10.1023/A:1009798010579 PG 32 WC Computer Science, Interdisciplinary Applications; Mathematics, Applied SC Computer Science; Mathematics GA 159GN UT WOS:000078164100004 ER PT J AU Phillips, CA Schulz, AS Shmoys, DB Stein, C Wein, J AF Phillips, CA Schulz, AS Shmoys, DB Stein, C Wein, J TI Improved bounds on relaxations of a parallel machine scheduling problem SO JOURNAL OF COMBINATORIAL OPTIMIZATION LA English DT Article DE scheduling; preemptive scheduling; release dates; identical parallel machines; average completion time; approximation algorithms; relaxations; linear programming ID TIME AB We consider the problem of scheduling n jobs with release dates on m identical parallel machines to minimize the average completion time of the jobs. We prove that the ratio of the average completion time of the optimal nonpreemptive schedule to that of the optimal preemptive schedule is at most 7/3, improving a bound of (3 - 1/m) due to Phillips, Stein and Wein. We then use our technique to give an improved bound on the quality of a linear programming relaxation of the problem considered by Hall, Schulz, Shmoys and Wein. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Tech Univ Berlin, Dept Math, D-1000 Berlin, Germany. Cornell Univ, Sch Operat Res & Ind Engn, Ithaca, NY 14853 USA. Cornell Univ, Dept Comp Sci, Ithaca, NY 14853 USA. Dartmouth Coll, Dept Comp Sci, Sudikoff Lab, Hanover, NH 03755 USA. Polytech Univ, Dept Comp Sci, Brooklyn, NY 11201 USA. RP Phillips, CA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 24 TC 8 Z9 11 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1382-6905 J9 J COMB OPTIM JI J. Comb. Optim. PY 1998 VL 1 IS 4 BP 413 EP 426 DI 10.1023/A:1009750913529 PG 14 WC Computer Science, Interdisciplinary Applications; Mathematics, Applied SC Computer Science; Mathematics GA 115UG UT WOS:000075683400006 ER PT J AU Saias, I AF Saias, I TI Optimal randomized scheduling by replacement SO JOURNAL OF COMBINATORIAL OPTIMIZATION LA English DT Article ID ALGORITHMS AB In the replacement scheduling problem, a system consists of n processors drawn from a pool of p, all initially "alive". At any time some processor can die. The scheduler is immediately informed of the fault but not of its location. It must then choose another set of n processors. If this new set contains a dead processor, the system crashes and halts. The performance of a scheduling protocol is measured by the expected number of deaths the system tolerates before it crashes. We provide an optimal randomized scheduling protocol for this problem. The framework of this work combines an absolute performance measure for protocols and so-called adaptive online adversaries. This framework is rarely addressed because of the complexity of the interaction between protocols and adversaries. A major contribution of our work is to provide a theoretical foundation for the analysis of this interaction. In particular we make explicit how the protocol and the adversary affect the probability distribution of the analysis-a very general problem. We carefully analyze the exchange of information between the two players, and reveal how they use their information optimally. The optimality of the protocol is established by using of a saddle point method for protocols and adversaries. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Saias, I (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1382-6905 J9 J COMB OPTIM JI J. Comb. Optim. PY 1998 VL 1 IS 4 BP 427 EP 456 DI 10.1023/A:1009703014438 PG 30 WC Computer Science, Interdisciplinary Applications; Mathematics, Applied SC Computer Science; Mathematics GA 115UG UT WOS:000075683400007 ER PT J AU Liszewski, MJ Bunde, RL Hemming, C Rosentreter, J Welhan, J AF Liszewski, MJ Bunde, RL Hemming, C Rosentreter, J Welhan, J TI The use of synthesized aqueous solutions for determining strontium sorption isotherms SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article AB The use of synthesized aqueous solutions for determining experimentally derived strontium sorption isotherms of sediment was investigated as part of a study accessing strontium chemical transport properties. Batch experimental techniques were used to determine strontium sorption isotherms using synthesized aqueous solutions designed to chemically represent water from a natural aquifer with respect to major ionic character and pH. A strontium sorption isotherm for a sediment derived using a synthesized aqueous solution was found to be most comparable to an isotherm derived using natural water when the synthesized aqueous solution contained similar concentrations of calcium and magnesium, However, it is difficult to match compositions exactly due to the effects of disequilibrium between the solution and the sediment, Strong linear relations between sorbed strontium and solution concentrations of calcium and magnesium confirm that these cations are important co-constituents in these synthesized aqueous solutions. Conversely, weak linear relations between sorbed strontium and solution concentrations of sodium and potassium indicate that these constituents do not affect sorption of strontium. The addition of silica to the synthesized aqueous solution does not appreciably affect the resulting strontium sorption isotherm. (C) 1998 Elsevier Science B.V. C1 US Geol Survey, Idaho Falls, ID 83403 USA. Idaho State Univ, Dept Chem, Pocatello, ID 83209 USA. Idaho State Univ, Dept Geol, Idaho Geol Survey, Pocatello, ID 83209 USA. RP Liszewski, MJ (reprint author), US Geol Survey, POB 2230, Idaho Falls, ID 83403 USA. NR 14 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7722 J9 J CONTAM HYDROL JI J. Contam. Hydrol. PD JAN PY 1998 VL 29 IS 2 BP 93 EP 108 DI 10.1016/S0169-7722(96)00098-8 PG 16 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA YW125 UT WOS:000071900400001 ER PT J AU Gomez-Vega, J Saiz, E Szebeszczyk, L Marshall, SJ Marshall, GW Tomsia, AP AF Gomez-Vega, J Saiz, E Szebeszczyk, L Marshall, SJ Marshall, GW Tomsia, AP TI Layered glass coatings on Ti implants. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Univ Calif San Francisco, San Francisco, CA 94143 USA. Lawrence Berkeley Lab, Berkeley, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1998 VL 77 SI A MA 17 BP 108 EP 108 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YU125 UT WOS:000071684800018 ER PT J AU Breunig, T Marshall, GW Kinney, JH Haupt, DL Marshall, SJ AF Breunig, T Marshall, GW Kinney, JH Haupt, DL Marshall, SJ TI X-ray tomographic microscopy of natural carious lesions SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Univ Calif San Francisco, San Francisco, CA 94143 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1998 VL 77 SI A MA 86 BP 116 EP 116 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YU125 UT WOS:000071684800088 ER PT J AU Miaw, CL Chou, HN Gruninger, SE Liu, J Siew, C AF Miaw, CL Chou, HN Gruninger, SE Liu, J Siew, C TI A novel method for removing mercury from dental wastewater. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 ADAHF, Chicago, IL 60611 USA. Pacific NW Lab, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1998 VL 77 SI A MA 295 BP 142 EP 142 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YU125 UT WOS:000071684800292 ER PT J AU Otis, LL Colston, BW Everett, MJ AF Otis, LL Colston, BW Everett, MJ TI Dental optical coherence tomography: A novel assessment of oral tissues SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Univ Connecticut, Sch Dent Med, Farmington, CT 06032 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1998 VL 77 SI A MA 977 BP 228 EP 228 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YU125 UT WOS:000071684800981 ER PT J AU Gallagher, R Balooch, M Balazs, A Lundkvist, AS Marshall, GW Marshall, SJ AF Gallagher, R Balooch, M Balazs, A Lundkvist, AS Marshall, GW Marshall, SJ TI Nanomechanical properties of hydrated carious human dentin. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1998 VL 77 SI A MA 1244 BP 261 EP 261 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YU125 UT WOS:000071684801240 ER PT J AU Ziemiecki, TL Colston, BW Everett, MJ Otis, LL AF Ziemiecki, TL Colston, BW Everett, MJ Otis, LL TI Optical coherence topography: A novel assessment of composite wear. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Univ Connecticut, Sch Dent Med, Farmington, CT 06032 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1998 VL 77 SI A MA 1367 BP 276 EP 276 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YU125 UT WOS:000071684801359 ER PT J AU Palmer, RJ Park, J Pedraza, AJ Suci, P Geesey, G Kolenbrander, PE White, DC AF Palmer, RJ Park, J Pedraza, AJ Suci, P Geesey, G Kolenbrander, PE White, DC TI Flowcell for combined FTIR spectroscopy confocal microscopy applied to oral biofilm research. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37932 USA. Univ Tennessee, Dept Mat Sci Engn, Knoxville, TN 37932 USA. Montana State Univ, Ctr Biofilm Engn, Bozeman, MT 59717 USA. NIDR, NIH, Bethesda, MD 20892 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 3 U2 3 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1998 VL 77 SI A MA 1455 BP 287 EP 287 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YU125 UT WOS:000071684801447 ER PT J AU Otis, LL Everett, MJ Colston, BW AF Otis, LL Everett, MJ Colston, BW TI Optical coherence tomography: A novel assessment of coronal restorations SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Univ Connecticut, Sch Dent Med, Farmington, CT 06032 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 1998 VL 77 SI B MA 1541 BP 824 EP 824 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA ZK546 UT WOS:000073335401532 ER PT J AU Christensen, RM AF Christensen, RM TI Two theoretical elasticity micromechanics models SO JOURNAL OF ELASTICITY LA English DT Article DE micromechanics; composites; elasticity AB This study is concerned with the Composite Spheres (Cylinders) Model and the Generalized Self Consistent Method (GSCM). A detailed examination of the two models proves the two models are the same in the limited cases where they both give solutions. In this process of comparison between the two models, a new solution is found for the shear property of a closed cell foam type idealization. C1 Stanford Univ, Stanford, CA 94305 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Christensen, RM (reprint author), Stanford Univ, Stanford, CA 94305 USA. NR 9 TC 36 Z9 36 U1 1 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0374-3535 J9 J ELASTICITY JI J. Elast. PY 1998 VL 50 IS 1 BP 15 EP 25 DI 10.1023/A:1007497600857 PG 11 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA 108QA UT WOS:000075275900002 ER PT J AU Yan, Y Chisholm, MF Duscher, G Pennycook, SJ AF Yan, Y Chisholm, MF Duscher, G Pennycook, SJ TI Atomic structure of a Ca-doped [001] tilt grain boundary in MgO SO JOURNAL OF ELECTRON MICROSCOPY LA English DT Article DE Z-contrast; EELS; STEM; grain boundary; MgO ID SIMULATION; CRYSTALS; SRTIO3 AB The atomic structure of a symmetric 24 degrees[001] tilt grain boundary in MgO has been derived directly from high-resolution Z-contrast images obtained in a scanning transmission electron microscope. The images indicate the presence of impurities (Z>12) and vacancies at the boundary. High spatial resolution electron energy-loss spectroscopy has been used to determine that the segregated impurity is Ca. The specific sites occupied by Ca are obtained from the image and bond valence sum analysis. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. RP Yan, Y (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Duscher, Gerd/G-1730-2014 OI Duscher, Gerd/0000-0002-2039-548X NR 20 TC 11 Z9 11 U1 0 U2 6 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0022-0744 J9 J ELECTRON MICROSC JI J. Electron Microsc. PY 1998 VL 47 IS 2 BP 115 EP 120 PG 6 WC Microscopy SC Microscopy GA ZT877 UT WOS:000074137400003 ER PT J AU Fossum, AF AF Fossum, AF TI Rate data and material model parameter estimation SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB Traditionally stress-strain data are used to estimate material parameters in viscoplastic material models. Since the models exist in rate form, they must be integrated in time for the duration of the laboratory tests to give response models for parameter estimation. In this paper the alternative is considered in which the rate form of the material models is fitted to time-differentiated stress-strain data. Material parameters, their 95 percent confidence intervals, and their correlation coefficients are compared with their counterparts determined from the more traditional stress versus strain form of the data. It was found that the use of the stress-rate form of the data gave well-determined parameter estimates with equivalent or superior fitting statistics to those determined in the conventional manner. It is concluded that different forms of the same data can be used to extract significant and distinct sensitivity coefficients to enhance the overall robustness fan optimization algorithm for parameter estimation. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Fossum, AF (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 9 TC 14 Z9 15 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0094-4289 J9 J ENG MATER-T ASME JI J. Eng. Mater. Technol.-Trans. ASME PD JAN PY 1998 VL 120 IS 1 BP 7 EP 12 DI 10.1115/1.2806842 PG 6 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA YR899 UT WOS:000071542700002 ER PT J AU Philippacopoulos, AJ AF Philippacopoulos, AJ TI Spectral Green's dyadic for point sources in poroelastic media SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article ID LAYERED HALF-SPACE; SEDIMENTS; WAVES; INFINITE AB A fairly detailed derivation of the spectral Green's dyadic for point sources in unbounded poroelastic media is presented. It is assumed that the motion of the poroelastic medium is governed by Blot's theory of poroelasticity; thus in a source-free unbounded space the wave field consists of two (fast and slow) longitudinal waves and a transverse wave. Considering a three-dimensional source-receiver system and then through a decomposition of the displacement and body force fields, the dilatational and rotational components of motion are separated. Separation yields two sets of systems of two partial differential equations representing scalar wave equations of poroelasticity, which unlike the case of elastic propagation are still coupled in terms of the motion of the pore fluid and that of the frame material, respectively. General solutions are derived from the fundamental eigenvalue problems of poroelasticity, which are associated with the systems of the homogeneous wave equations. Singular solutions for point sources are then obtained by superimposing the latter with particular solutions of the inhomogeneous wave equations. Consistent with previous studies, the spectral Green's dyadic shows that the body force singularity generates three distinct waves. These waves are radiating from the source with wave speeds, attenuations, and amplitudes, which depend on frequency and consequently on the level and type of dissipation in the two-phase medium. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Philippacopoulos, AJ (reprint author), SUNY Stony Brook, Stony Brook, NY 11794 USA. NR 21 TC 13 Z9 13 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD JAN PY 1998 VL 124 IS 1 BP 24 EP 31 DI 10.1061/(ASCE)0733-9399(1998)124:1(24) PG 8 WC Engineering, Mechanical SC Engineering GA YM233 UT WOS:000071043100004 ER PT J AU Macalady, JL Fuller, ME Scow, KM AF Macalady, JL Fuller, ME Scow, KM TI Effects of metam sodium fumigation on soil microbial activity and community structure SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID CARBON-SOURCE UTILIZATION; FATTY-ACID COMPOSITION; METHYL ISOTHIOCYANATE; BACTERIAL COMMUNITIES; UTILIZATION PATTERNS; BIOMASS; REPRODUCIBILITY; MICROORGANISMS; PESTICIDES; DIVERSITY AB Metam sodium (MS) is a widely used soil fumigant with broad biocidal activity. The impart of MS on soil microbial community structure and function is largely unknown, We investigated the effects of fumigation with field-relevant doses of MS in soil microcosms using traditional heterotrophic activity measures (C acid N mineralization), a substrate-utilization assay, and fatty acid analysis. Our results suggest that fumigation,vith MS results in persistent changes (at least 18 wk) in heterotrophic activity and fatty acid composition of the microbial biomass, Lack of recovery of heterotrophic activity and changes in fatty acid composition after fumigation suggest that MS has the potential to alter important microbially mediated functions such as nutrient cycling and pollutant degradation, Preliminary fatty acid data suggest that actinomycetes and other gram-positive organisms may recover preferentially after fumigation with MS, Although community fatty acid analysis shows promise as a screening tool in soil microbial toxicity studies, more detailed information can be obtained from analysis of phospholipid fatty acid (PLFA) and other specific lipid fractions. C1 Univ Calif Davis, Dept Land Air & Water Resources, Davis, CA 95616 USA. Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Macalady, JL (reprint author), Univ Calif Davis, Dept Land Air & Water Resources, Davis, CA 95616 USA. NR 50 TC 44 Z9 50 U1 0 U2 13 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 USA SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD JAN-FEB PY 1998 VL 27 IS 1 BP 54 EP 63 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA YT805 UT WOS:000071646800009 ER PT J AU Quinn, NWT Clyde, JR AF Quinn, NWT Clyde, JR TI A bed sediment sampler for precise depth profiling of contaminant concentrations in aquatic environments SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article AB A bed sediment and detritus sampler has been dec eloped for use in aquatic environments, such as in canals, rivers or lakes, for determining precise depth profiles of contaminants, The device is superior to currently available commercial push-tube and piston samplers in its simplicity, ease of use and its ability to retrieve and extrude sample cores. The sampler has been used with success during the past 12 mo to determine a profile of bed sediment Se concentrations within an earth-lined canal, alternatively used for conveyance of agricultural drainage and wetland water supply. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Quinn, NWT (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Bldg 50E-134,1 Cyclotron Rd, Berkeley, CA 94720 USA. OI Quinn, Nigel/0000-0003-3333-4763 NR 6 TC 4 Z9 4 U1 0 U2 1 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 USA SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD JAN-FEB PY 1998 VL 27 IS 1 BP 64 EP 67 PG 4 WC Environmental Sciences SC Environmental Sciences & Ecology GA YT805 UT WOS:000071646800010 ER PT J AU Lasat, MM Fuhrmann, M Ebbs, SD Cornish, JE Kochian, LV AF Lasat, MM Fuhrmann, M Ebbs, SD Cornish, JE Kochian, LV TI Phytoremediation of a radiocesium-contaminated soil: Evaluation of cesium-137 bioaccumulation in the shoots of three plant species SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID CROPS; WHEAT; AVAILABILITY; KINETICS AB A field study was conducted to investigate the potential of three plant species for phytoremediation of a Cs-137-contaminated site. Approximately 40-fold more Cs-137 was removed from the contaminated soil in shoots of red root pigweed (Amaranthus retroflexus L.) than in those of Indian mustard [Brassica juncea (L.) Czern] and tepary bean (Phaseolus acutifolius A. Gray), The greater potential for Cs-137 removal from the soil by A. retroflexus was associated with both high concentration of Cs-137 in shoots and high shoot biomass production. Approximately 3% of the total Cs-137 was removed from the top 15 cm of the soil (which contained most of the soil radiocesium) in shoots of 3-mo-old A, retroflexus plants. Soil leaching tests conducted with 0.1 and 0.5 M NH4NO3 solutions eluted as much as 15 and 19%, respectively, of the soil Cs-137, Addition of NH4NO3 to the soil, however, had no positive effect on Cs-137 accumulation in shoots in any of the species investigated. It is proposed that either NH4NO3 solution quickly percolated through the soil before interacting at specific Cs-137 binding sites or radiocesium mobilized by NH?NO, application moved below the rhizosphere, becoming unavailable for root uptake. Further research is required to optimize the phytotransfer of the NH4NO3-mobilized Cs-137. With two croppings of A. retroflexus per year and a sustained rate of extraction, phytoremediation of this Cs-137-contaminated soil appears feasible in <15 yr. C1 Cornell Univ, Plant Soil & Nutr Lab, USDA ARS, Ithaca, NY 14853 USA. Brookhaven Natl Lab, Environm & Waste Technol Ctr, Upton, NY 11973 USA. MSE Technol Applicat Inc, Butte, MT 59702 USA. RP Kochian, LV (reprint author), Cornell Univ, Plant Soil & Nutr Lab, USDA ARS, Ithaca, NY 14853 USA. EM lvk1@cornell.edu OI Kochian, Leon/0000-0003-3416-089X; Ebbs, Stephen/0000-0003-4042-9234 NR 24 TC 72 Z9 90 U1 4 U2 32 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 USA SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD JAN-FEB PY 1998 VL 27 IS 1 BP 165 EP 169 PG 5 WC Environmental Sciences SC Environmental Sciences & Ecology GA YT805 UT WOS:000071646800023 ER PT J AU Waugh, WJ Carroll, J Abraham, JD Landeen, DS AF Waugh, WJ Carroll, J Abraham, JD Landeen, DS TI Applications of dendrochronology and sediment geochronology to establish reference episodes for evaluations of environmental radioactivity SO JOURNAL OF ENVIRONMENTAL RADIOACTIVITY LA English DT Article ID TREE RINGS; PB-210 AB Dendrochronology and sediment geochronology have been used to demonstrate retrospective monitoring of environmental radioactivity at United States Department of Energy (DOE) sites. C-14 in annual growth rings of sagebrush preserved the temporal and spatial patterns of C-14 resulting from dispersion downwind of a nuclear fuel processing facility at the Hanford Site in Washington State. As far as 10 km downwind of the facility, C-14 concentrations were significantly higher in growth rings formed during a fuel processing episode than in rings produced during preoperational or postoperational episodes. An episode of uranium mill tailings deposition in pond sediments at the Grand Junction Office in Colorado was reconstructed using Pb-210 geochronology constrained by a marker of peak Cs-137 fallout. Uranium concentrations in ponds sediments deposited after the processing episode provide a reasonable cleanup standard. These reference episodes of environmental radioactivity reconstructed from measurements taken within contaminated environments can improve or replace reference area data as baseline information for dose reconstructions, risk assessments, and the establishment of cleanup standards. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Roy F Weston Inc, US DOE, Grand Junction Off, Grand Junction, CO 81503 USA. RP Waugh, WJ (reprint author), Roy F Weston Inc, US DOE, Grand Junction Off, 2597 B 3-4 Rd, Grand Junction, CO 81503 USA. NR 30 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0265-931X J9 J ENVIRON RADIOACTIV JI J. Environ. Radioact. PY 1998 VL 41 IS 3 BP 269 EP 286 DI 10.1016/S0265-931X(98)00002-2 PG 18 WC Environmental Sciences SC Environmental Sciences & Ecology GA 118RX UT WOS:000075854700003 ER PT J AU Poston, TM Jaquish, RE Antonio, EJ Patton, GW AF Poston, TM Jaquish, RE Antonio, EJ Patton, GW TI Strontium-90 in alfalfa (Medicago sativa) around the Hanford site in southeastern Washington state: An evaluation of surveillance data SO JOURNAL OF ENVIRONMENTAL RADIOACTIVITY LA English DT Article AB From 1988-1994, Sr-90 concentrations in alfalfa (Medicago sativa) grown in areas receiving irrigation water from the Columbia River downstream of Hanford have exceeded concentrations observed in alfalfa grown nearby using other irrigation water sources. Surveillance data indicate that the relationship is not linked to atmospheric releases from Hanford. Attributing the apparent differences in Sr-90 concentrations to irrigation water is equivocal. Evaluations of Sr-90 in columbia River water fail to consistently show a statistically significant (P > 0.05) contribution at locations immediately downstream of Hanford. Modeling of past Sr-90 fallout accumulation in soil indicates that the potential contribution from Hanford liquid effluents entering the Columbia River, subsequently used as irrigation water from 1972 to 1992, would account for similar to 2% of Sr-90 in soil. The remaining 98% arises from historic atomic weapons testing fallout. Radiological doses modeled for an alfalfa-cow's milk-human pathway indicate that the maximum 50 year effective dose equivalent to a standard man who consumes 270 l of milk per year was 0.9 mu S upsilon, which is < 0.03% of the 3 mS upsilon annual dose resulting from natural sources of radiation exposure. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Poston, TM (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 16 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0265-931X J9 J ENVIRON RADIOACTIV JI J. Environ. Radioact. PY 1998 VL 39 IS 1 BP 87 EP 105 DI 10.1016/S0265-931X(97)00034-9 PG 19 WC Environmental Sciences SC Environmental Sciences & Ecology GA ZE717 UT WOS:000072823500007 ER PT J AU Beasley, TM Kelley, JM Orlandini, KA Bond, LA Aarkrog, A Trapeznikov, AP Pozolotina, VN AF Beasley, TM Kelley, JM Orlandini, KA Bond, LA Aarkrog, A Trapeznikov, AP Pozolotina, VN TI Isotopic Pu, U, and Np signatures in soils from Semipalatinsk-21, Kazakh Republic and the Southern Urals, Russia SO JOURNAL OF ENVIRONMENTAL RADIOACTIVITY LA English DT Article ID NUCLEAR TEST SITE; TECHA RIVER; RADIOACTIVE CONTAMINATION; RADIONUCLIDES AB Mass spectrometry measurements of Pu, U and Np isolated fr om soils contaminated by the 1957 accident at the Mayak nuclear complex in the Southern Ural mountains ('Kyshtym accident') and from soils collected at and near the Former Soviet Union (FSU) test site at Semipalatinsk-21 are reported. The results provide a coherent isotopic data set suggesting (I) that Pu recovered from irradiated uranium fuels processed at Mayak formed the source material for Pu devices tested at Semipalatinsk-21; (2) that (237)Np in the breached Mayak storage tank resulted, principally, from enrichment of this radionuclide in waste streams during the processing of low burn-up uranium fuels to recover both Pu and U and (3) the presence of (236)U at both sites may be useful in tracing inputs of this, and other transuranic radionuclides, to nearby river systems that flow to the Arctic Ocean. Published by Elsevier Science Ltd. C1 US DOE, New York, NY 10014 USA. RP Beasley, TM (reprint author), US DOE, 201 Varick St,5th Floor, New York, NY 10014 USA. RI Pozolotina, Vera/C-3560-2014 NR 26 TC 50 Z9 50 U1 2 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0265-931X J9 J ENVIRON RADIOACTIV JI J. Environ. Radioact. PY 1998 VL 39 IS 2 BP 215 EP 230 DI 10.1016/S0265-931X(97)00050-7 PG 16 WC Environmental Sciences SC Environmental Sciences & Ecology GA ZE718 UT WOS:000072823600008 ER PT J AU Beasley, T Cooper, LW Grebmeier, JM Aagaard, K Kelley, JM Kilius, LR AF Beasley, T Cooper, LW Grebmeier, JM Aagaard, K Kelley, JM Kilius, LR TI Np-237/I-129 atom ratios in the Arctic Ocean: Has Np-237 from western European and Russian fuel reprocessing facilities entered the Arctic Ocean? SO JOURNAL OF ENVIRONMENTAL RADIOACTIVITY LA English DT Article ID IRISH-SEA; TRANSURANIC ELEMENTS; WINDSCALE DISCHARGES; PLUTONIUM; SEDIMENT; RADIONUCLIDES; CIRCULATION; SELLAFIELD; TRACER; NEPTUNIUM AB Radioactive waste discharges from European nuclear fuel reprocessing facilities have introduced a suite of radionuclides (Sr-90, Tc-99, I-129, Cs-134, and Cs-137) into the Arctic Ocean by advection of North Atlantic water through the Norwegian Sea and Fram Strait. Measurements made in 1994 of Np-237 (T-1/2 = 2.14 x 10(6) year) and I-129 (T-1/2 = 15.7 x 10(6) year) in surface waters (0-300 m) of the Arctic Ocean show a strong linear correlation in their concentrations below the Polar Mixed Layer (30-50 m) indicating that Np-237 discharged from these same facilities (principally Sellafield) has entered the Arctic Ocean. Budget calculations indicate that global fallout carried with runoff plus dischargers from Russian reprocessing facilities have contributed Np-237 to the upper Arctic Ocean in about equal proportions, but their combined total is less than half that from Sellafield. Fallout from the Chernobyl accident added insignificant amounts of Np-237 and I-129 to the Arctic Ocean compared to discharges from Sellafield and La Hague. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 US DOE, New York, NY 10014 USA. RP Beasley, T (reprint author), US DOE, New York, NY 10014 USA. RI Cooper, Lee/E-5251-2012; Grebmeier, Jacqueline/L-9805-2013 OI Cooper, Lee/0000-0001-7734-8388; Grebmeier, Jacqueline/0000-0001-7624-3568 NR 59 TC 17 Z9 17 U1 0 U2 7 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0265-931X J9 J ENVIRON RADIOACTIV JI J. Environ. Radioact. PY 1998 VL 39 IS 3 BP 255 EP 277 DI 10.1016/S0265-931X(97)00059-3 PG 23 WC Environmental Sciences SC Environmental Sciences & Ecology GA ZJ552 UT WOS:000073228200003 ER PT J AU Cooper, LW Larsen, IL Beasley, TM Dolvin, SS Grebmeier, JM Kelley, JM Scott, M Johnson-Pyrtle, A AF Cooper, LW Larsen, IL Beasley, TM Dolvin, SS Grebmeier, JM Kelley, JM Scott, M Johnson-Pyrtle, A TI The distribution of radiocesium and plutonium in sea ice-entrained Arctic sediments in relation to potential sources and sinks SO JOURNAL OF ENVIRONMENTAL RADIOACTIVITY LA English DT Article ID RADIOACTIVE CONTAMINATION; SURFACE SEDIMENTS; BEAUFORT SEA; ALASKA; TRANSPORT; CS-137; PB-210; CARBON; RIVER AB Gamma counting of a range of grain size fractions of sediments entrained in Arctic Ocean sea ice indicate that the wide range of radiocesium activities that are observed in bulk samples are primarily a function of the geographical origin of the sediment, rather than mineral composition, or physical processes that increase the content of fine clays in sediments. Plutonium isotope ratios (Pu-240:Pu-239) of sea ice sediments are consistent with an ultimate origin of the plutonium from bomb fallout Pu-240:Pu-239 = similar to 0.18), and these sediment ratios differ significantly in plutonium isotope ratios from deep sea sediments of the Arctic Ocean. Much lower plutonium activities were observed in deep sea sediments relative to the sea ice entrained sediments. These differences in isotopic ratios indicate that on decadal scales, sedimentation of bomb fallout plutonium is not the sole source of plutonium to deep Arctic Ocean sediments, The large differences in total plutonium activity between some of the sea ice entrained sediments and all of the deep Arctic Ocean sediments also suggest that the total flux of plutonium from sea ice entrained sediments to the deep sea may be relatively small. Radiocesium activity in the sea ice entrained sediments is well correlated with total plutonium abundance, but the best-fit regression line does not pass through the origin, indicating that a small secondary source of cesium (3 to 9 Bq kg(-1) dry weight) that is free of plutonium may contribute to the radiocesium activity observed in sediments entrained in Arctic Ocean sea ice. Based upon observations of carbon:nitrogen weight/weight ratios in excess of 20 in the organic carbon fraction, together with delta(13)C values less than -23%, several of the sea ice entrained sediments show indications of estuarine origin. However, these specific samples typically have low radionuclide burdens. Consideration of the low smectite content (< similar to 20% by weight) in all of the sea ice sediments and prevailing sea ice transport patterns suggest that a Siberian shelf origin west of the Lena River is improbable for any of the sea ice sediment samples. Nevertheless, in the absence of clear mechanisms for significantly increasing the radionuclide burden in sediments incorporated into sea ice, the radioactivity in the sediment source area appears to be the most crucial determinant of the ultimate radionuclide burden in sea ice sediments. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Cooper, LW (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008,MS 6038, Oak Ridge, TN 37831 USA. RI Cooper, Lee/E-5251-2012; Grebmeier, Jacqueline/L-9805-2013 OI Cooper, Lee/0000-0001-7734-8388; Grebmeier, Jacqueline/0000-0001-7624-3568 NR 47 TC 29 Z9 29 U1 2 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0265-931X J9 J ENVIRON RADIOACTIV JI J. Environ. Radioact. PY 1998 VL 39 IS 3 BP 279 EP 303 DI 10.1016/S0265-931X(97)00058-1 PG 25 WC Environmental Sciences SC Environmental Sciences & Ecology GA ZJ552 UT WOS:000073228200004 ER PT J AU Beasley, TM Kelley, JM Maiti, TC Bond, LA AF Beasley, TM Kelley, JM Maiti, TC Bond, LA TI Np-237/Pu-239 atom ratios in integrated global fallout: a reassessment of the production of Np-237 SO JOURNAL OF ENVIRONMENTAL RADIOACTIVITY LA English DT Article ID PLUTONIUM AB It is estimated that as much as 3 tons of Np-237 (T-1/2 = 2.14 x 10(6) years) was released to the environment during the above-ground testing of nuclear weapons. This estimate is based on the analysis of Np-237/Pu-239 atom ratios (0.7 +/- 0.2) in soil samples believed to have captured the entire global fallout record. In the course of several studies dealing with the behavior of transuranic radionuclides in different ecosystems, we measured the Np-237/Pu-239 atom ratios in a variety of soils throughout the northern hemisphere, including repetitive analyses of the soils used to establish the ratio cited above. Our data argue for a global Np-237/Pu-239 fallout ratio near 0.45 and a total Np-237 production of similar to 1.5 tons. Published by Elsevier Science Ltd. RP Beasley, TM (reprint author), US DOE,201 VARICK ST,NEW YORK,NY 10014, USA. NR 20 TC 41 Z9 43 U1 1 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0265-931X J9 J ENVIRON RADIOACTIV JI J. Environ. Radioact. PY 1998 VL 38 IS 2 BP 133 EP 146 DI 10.1016/S0265-931X(97)00033-7 PG 14 WC Environmental Sciences SC Environmental Sciences & Ecology GA YJ422 UT WOS:A1998YJ42200001 ER PT J AU Ward, TE Bulmer, D Walton, MR Apel, WA AF Ward, TE Bulmer, D Walton, MR Apel, WA TI Development of genetically engineered bacteria for trichloroethylene degradation SO JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING LA English DT Article DE toluene monooxygenase; TCE; broad-host-range vector ID PSEUDOMONAS-MENDOCINA KR1; BROAD-HOST-RANGE; CLONING VECTORS; COPY-NUMBER; TOLUENE-4-MONOOXYGENASE; SYSTEM; PUTIDA AB The genes coding for toluene monooxygenase (TMO), an enzyme also capable of degrading trichloroethylene (TCE), from Pseudomonas mendocina KR1 were cloned into both narrow-and broad-host-range vectors and introduced into Escherichia coli and P. putida. TMO activity expressed by a number of strain/plasmid combinations was assayed by determining decreases in the fluorescence of indole. Degradation of TCE was investigated in sealed serum vials for a number of these combinations. Finally a kinetic experiment, involving determination of the rate of TCE degradation at various TCE concentrations, was performed, and approximate kinetic constants for TCE degradation by these two species were determined. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Ward, TE (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. OI Walton, Michelle/0000-0003-4169-4443 NR 12 TC 1 Z9 1 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1093-4529 J9 J ENVIRON SCI HEAL A JI J. Environ. Sci. Health Part A-Toxic/Hazard. Subst. Environ. Eng. PY 1998 VL 33 IS 2 BP 179 EP 193 PG 15 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA ZH865 UT WOS:000073155200002 ER PT J AU Sega, GA Tomkins, BA Griest, WH Bayne, CK AF Sega, GA Tomkins, BA Griest, WH Bayne, CK TI The hydrolysis of di-isopropyl methylphosphonate in ground water SO JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING LA English DT Article DE di-isopropyl methylphosphonate; hydrolysis rate; half-life; ground water ID DEGRADATION; PESTICIDES AB The half-life of di-isopropyl methylphosphonate (DIMP) in ground water at 10 degrees C was estimated to be 500 years with a 95% confidence interval of 447 to 559 years from measurements of the hydrolysis rates at four temperatures ranging between 70 and 98 degrees C. First-order kinetics were assumed, and the Arrhenius equation was used to extrapolate the hydrolysis rates to the normal temperature of ground water, 10 degrees C. The half-life calculated at this temperature for ASTM Type II water was estimated to be 684 years with a 95% confidence interval of 470 to 995 years, in agreement with a previously published study. The major hydrolysis products detected were isopropyl methylphosphonic acid and methylphosphonic acid. After heating samples for 43 days at 90 degrees C, the molar accounting of the remaining DIMP and its detected hydrolysis products was 15% of the starting material. Inorganic phosphate was not detected. The very slow rate of DIMP hydrolysis in ground water suggests that the unidentified products are not likely to accumulate to any significant extent. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RP Sega, GA (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. OI Tomkins, Bruce/0000-0001-8520-1415 NR 18 TC 2 Z9 2 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1093-4529 J9 J ENVIRON SCI HEAL A JI J. Environ. Sci. Health Part A-Toxic/Hazard. Subst. Environ. Eng. PY 1998 VL 33 IS 2 BP 213 EP 236 PG 24 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA ZH865 UT WOS:000073155200004 ER PT J AU Fresquez, PR Armstrong, DR Mullen, MA AF Fresquez, PR Armstrong, DR Mullen, MA TI Radionuclides in soils collected from within and around Los Alamos National Laboratory: 1974-1996 SO JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING LA English DT Article DE U; Am-241; Cs-137; Pu-238; Pu-239,Pu-240; Sr-90; H-3; contamination; exposure ID PLUTONIUM; CS-137; AM-241 AB A soil sampling program is the most direct means of determining the types, concentration/activity, and distribution of radionuclides within and around nuclear facilities. Los Alamos National Laboratory (LANL), for example, has had a soil surveillance program since the early 1970s and the purpose of this paper was to 1) evaluate this 20+ year data set to determine if there are any statistical differences in radionuclides (H-3, Cs-137, Pu-238, Pu-239,Pu-240, Am-241, Sr-90, U-tot) and radioactivity (gross alpha, beta, and gamma), as a function of air emissions and fugitive dust, in surface soils (0-5 cm depth) collected from LANL, perimeter (PM) and background (BG) sites, and 2) determine if radionuclide concentrations are increasing or decreasing over time. Also, the total effective dose equivalent (TEDE) and the corresponding risk of excess cancer fatalities (RECF) to a PM community were estimated. Based on the long-term average, nine out of the ten radionuclide parameters measured in LANL soils (n=12) were significantly (p<0.05) higher in concentration than BG (n=6). Perimeter soils (n=10), on the other hand, showed less differences with only four out of the ten parameters being statistically higher in concentration than BG. Most radionuclides in LANL and PM areas, with the exception of Pu-238 in soils from PM, significantly decrease in concentration over time, so that by 1996 most radionuclides were approaching values similar to BG. The maximum net positive TEDE (i.e., the TEDE + two sigma for each radioisotope minus background and then only the positive doses summed) for a resident living around the PM of LANL, as modeled by the residual radioactive (RESRAD) code using a residential scenario for soils collected from 1974-1996, 1993-1996, and in 1996 was 2.9 mrem y(-1) (29 mu Sv y(-1)), 2.3 mrem y(-1) (23 mu Sv y(-1)), and 0.8 mrem y(-1) (8 mu Sv y(-1)), respectively. All upper bound TEDEs were far below the International Commission of Radiological Protection permissible dose limit of 100 mrem y(-1) (1000 mu Sv y(-1)) for all pathways, and the highest TEDE corresponds to a RECF of 1.5 x 10(-6)-an estimate far below the Environmental Protection Agency guideline of 10(-4). C1 Univ Calif Los Alamos Natl Lab, Environm Safety & Hlth Div, Los Alamos, NM 87545 USA. RP Fresquez, PR (reprint author), Univ Calif Los Alamos Natl Lab, Environm Safety & Hlth Div, M887, Los Alamos, NM 87545 USA. NR 33 TC 8 Z9 8 U1 2 U2 3 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1093-4529 J9 J ENVIRON SCI HEAL A JI J. Environ. Sci. Health Part A-Toxic/Hazard. Subst. Environ. Eng. PY 1998 VL 33 IS 2 BP 263 EP 278 PG 16 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA ZH865 UT WOS:000073155200007 ER PT J AU Sharma, VK Bloom, JT Joshi, VN AF Sharma, VK Bloom, JT Joshi, VN TI Oxidation of ammonia by ferrate(VI) SO JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING LA English DT Article DE oxidation; removal; kinetics; ammonia; ferrate(VI) ID PULSE-RADIOLYSIS; REACTIVITY; ACIDS AB The kinetics of ammonia oxidation by ferrate(VI) was determined as a function of pH (7.5-11.0) and temperature (10-35 degrees C). The rates decrease with increase in pH. The pH dependence is probably related to protonation of ferrate(VI) and ammonia. The theoretical curve through data gave the rate constants; k(7)(HFeO4- + NH4+) = 8.46 +/- 0.50 x 10(-1) M-1 s(-1); ks(FeO42- + NH4+) = 1.26 +/- 0.11 x 10(-1) M-1 s(-1); k(10)(FeO42- + NH3) = 1.19 +/- 0.10 x1 0(-1) M-1 s(-1). The activation parameters, Delta H-not equal and Delta S-not equal were found to be 67.3 +/- 3.5 kJ/mol and 33.1 +/- 0.2 J/mol.K, respectively. When ferrate(VI) was used in excess relative to ammonia in the oxidation reaction, 22 % of ammonia removal was achieved. The usefulness of ferrate(VI) to remove ammonia from wastewater is discussed. C1 Texas A&M Univ, Dept Chem, Corpus Christi, TX 78412 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Sharma, VK (reprint author), Texas A&M Univ, Dept Chem, 6300 Ocean Dr, Corpus Christi, TX 78412 USA. OI Sharma, Virender/0000-0002-5980-8675 NR 28 TC 38 Z9 41 U1 1 U2 16 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1093-4529 J9 J ENVIRON SCI HEAL A JI J. Environ. Sci. Health Part A-Toxic/Hazard. Subst. Environ. Eng. PY 1998 VL 33 IS 4 BP 635 EP 650 PG 16 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA ZN088 UT WOS:000073608400007 ER PT J AU Fresquez, PR Armstrong, DR Mullen, MA Naranjo, L AF Fresquez, PR Armstrong, DR Mullen, MA Naranjo, L TI The uptake of radionuclides by beans, squash, and corn growing in contaminated alluvial soils at Los Alamos National Laboratory SO JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART B-PESTICIDES FOOD CONTAMINANTS AND AGRICULTURAL WASTES LA English DT Article DE crops; radionuclides; contamination; translocation; exposure; risk ID CONCENTRATION RATIO; PLUTONIUM; LINEARITY; CS-137 AB Pinto beans (Phaselous vulgar-is), sweet corn (Zea mays), and zucchini squash (Cucurbita pepo) were grown in a field pot study using alluvial floodplain soils contaminated with various radionuclides within Los Alamos Canyon (LAG) at Los Alamos National Laboratory, New Mexico. Soils as well as washed edible (fruit) and nonedible (stems and leaves) crop tissues were analyzed for tritium (H-3), cesium (Cs-137), strontium (Sr-90), plutonium (Pu-238 and Pu-239,Pu-240), americium (Am-241), and total uranium (U-tot). Most radionuclides, with the exception of H-3 and U-tot, in soil and crop tissues from LAC were detected in significantly higher concentrations (p <0.05) than in soil or crop tissues collected from regional background locations. Significant differences in radionuclide concentrations among crop species (squash were generally higher than beans or corn) and plant parts (nonedible tissue were generally higher than edible tissue) were observed. Most soil-to-plant concentration ratios for radionuclides in edible and nonedible crop tissues grown in soils from LAC were within default values in the literature commonly used in dose and risk assessment models. Overall, the maximum net positive committed effective dose equivalent (CEDE)-the CEDE plus two sigma for each radioisotope minus background and then all positive doses summed-to a hypothetical 50-year resident that ingested 352 Ib ([160 kg]; the maxiumum ingestion rate per person per year) of beans, corn, and squash in equal proportions was 74 mrem y(-1) (740 mu S y(-1)). This upper bound dose was below the International Commission on Radiological Protection permissible dose limit of 100 mrem y(-1) (1000 mu S y(-1)) from all pathways and corresponds to a risk of an excess cancer fatality of 3.7 x 10(-5) (37 in a million), which is also below the U.S. Environmental Protection Agency's guideline of 10(-4). C1 Univ Calif Los Alamos Natl Lab, Environm Safety & Hlth Div, Los Alamos, NM 87545 USA. RP Fresquez, PR (reprint author), Univ Calif Los Alamos Natl Lab, Environm Safety & Hlth Div, M887, Los Alamos, NM 87545 USA. NR 47 TC 14 Z9 14 U1 0 U2 14 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0360-1234 J9 J ENVIRON SCI HEAL B JI J. Environ. Sci. Health Part B-Pestic. Contam. Agric. Wastes PY 1998 VL 33 IS 1 BP 99 EP 121 DI 10.1080/03601239809373132 PG 23 WC Environmental Sciences; Public, Environmental & Occupational Health SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health GA YY133 UT WOS:000072116600007 PM 9491570 ER PT J AU Daisey, JM AF Daisey, JM TI A report on the workshop on improving exposure analysis for DOE sites September, 1996, San Francisco, CA SO JOURNAL OF EXPOSURE ANALYSIS AND ENVIRONMENTAL EPIDEMIOLOGY LA English DT Article DE environmental clean-up; exposure analysis; nuclear waste; total exposure; worker exposure records AB In the aftermath of the Cold War the U.S. Department of Energy (DOE) was left with the legacy of five decades of nuclear weapons production-large volumes of nuclear and chemicals wastes and stockpiled nuclear materials. In 1989, DOE created the Office of Environmental Management (EM) to conduct environmental restoration and compliance activities and to manage these wastes and nuclear materials. In 1995, DOE initiated an effort to evaluate health and environmental risks within each of the DOE sires (using Risk Data Sheets) to help set priorities for environmental clean-up. Since reduction of health risks invariably requires reductions of exposure, scientifically sound and defensible analyses of both current and potential future exposures of workers, local communities, and Indian Nations are required if DOE/EM is to achieve its mission of protection of human health and the environment. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Indoor Environm Program, Berkeley, CA 94720 USA. RP Daisey, JM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Indoor Environm Program, Berkeley, CA 94720 USA. NR 0 TC 18 Z9 19 U1 1 U2 2 PU PRINCETON SCIENTIFIC PUBL INC PI PRINCETON PA PO BOX 2155, PRINCETON, NJ 08543 USA SN 1053-4245 J9 J EXPO ANAL ENV EPID JI J. Expo. Anal. Environ. Epidemiol. PD JAN-MAR PY 1998 VL 8 IS 1 BP 3 EP 7 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA YT398 UT WOS:000071598900002 PM 9470100 ER PT J AU Pulkkinen, TI Baker, DN Frank, LA Sigwarth, JB Opgenoorth, HJ Greenwald, R Friis-Christensen, E Mukai, T Nakamura, R Singer, H Reeves, GD Lester, M AF Pulkkinen, TI Baker, DN Frank, LA Sigwarth, JB Opgenoorth, HJ Greenwald, R Friis-Christensen, E Mukai, T Nakamura, R Singer, H Reeves, GD Lester, M TI Two substorm intensifications compared: Onset, expansion, and global consequences SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID THIN CURRENT SHEETS; SOLAR-WIND; MAGNETOSPHERIC SUBSTORMS; RECOVERY PHASE; PLASMA SHEET; GROWTH-PHASE; MAGNETOTAIL; CONVECTION; MODEL; SPACECRAFT AB We present observations of two sequential substorm onsets on May 15, 1996. The first event occurred during persistently negative IMF B-Z, whereas the second expansion followed a northward turning of the interplanetary magnetic field (IMF). While the first onset remained localized, the second event led to a major reconfiguration of the magnetotail, The two very different events are contrasted, and it is suggested that the IMF direction controls the evolution of the expansion phase after the initial onset. Magnetic field modeling and field-aligned mappings are used to find the high-altitude source region of the auroral features and currents giving rise to ground magnetic disturbances: It is shown that the auroral brightening is related to processes near the inner edge of the plasma sheet but that the initial field-aligned currents couple to the midtail region. Ground magnetograms show an abrupt, large-scale weakening of the electrojet during the recovery phase. This event is followed by eastward drifting omega bands in a double-oval configuration, During that period, the Geotail plasma data show oscillations at <100 km/s amplitude. We argue that both these features are connected with the global tail evolution as the neutral line ceases to be active and reforms in the distant tail. C1 Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Danish Meteorol Inst, DK-2100 Copenhagen, Denmark. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Leicester, Dept Phys, Leicester LE1 7RH, Leics, England. Nagoya Univ, Solar Terr Environm Lab, Aichi 442, Japan. Swedish Inst Space Phys, Uppsala Div, S-75590 Uppsala, Sweden. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. RP Pulkkinen, TI (reprint author), Finnish Meteorol Inst, POB 503, FIN-00101 Helsinki, Finland. RI Nakamura, Rumi/I-7712-2013; Reeves, Geoffrey/E-8101-2011; Pulkkinen, Tuija/D-8403-2012; OI Nakamura, Rumi/0000-0002-2620-9211; Reeves, Geoffrey/0000-0002-7985-8098; Pulkkinen, Tuija/0000-0002-6317-381X; Greenwald, Raymond/0000-0002-7421-5536 NR 48 TC 41 Z9 41 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 15 EP 27 DI 10.1029/97JA01985 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900003 ER PT J AU Jordanova, VK Farrugia, CJ Janoo, L Quinn, JM Torbert, RB Ogilvie, KW Lepping, RP Steinberg, JT McComas, DJ Belian, RD AF Jordanova, VK Farrugia, CJ Janoo, L Quinn, JM Torbert, RB Ogilvie, KW Lepping, RP Steinberg, JT McComas, DJ Belian, RD TI October 1995 magnetic cloud and accompanying storm activity: Ring current evolution SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; GEOMAGNETIC STORMS; MAGNETOSPHERIC MODEL; IONS; PROTON; EARTH; DISTURBANCES; PARTICLES; PASSAGE; FIELDS AB The passage at Earth of the October 1995 magnetic cloud and the high-speed corotating stream overtaking it,monitored by the Global Geospace Science (GGS) spacecraft Wind, caused two consecutive geomagnetic storms: a major one during the strong B-z < 0 nT phase of cloud passage and a moderate one during the intermittent B-z < 0 activity in the fast corotating stream. Large dynamic pressure changes were observed in the sheath region ahead of the cloud and in the cloud-stream interface region at its rear, resulting in substantial corrections to the measured Dst index. A burst of superdense plasma sheet extending over similar to 2 hours in local time was observed at geostationary orbit during the second storm. We simulate the ring current development during this storm period using our kinetic model and calculate the magnetic field perturbation caused by the ring current. The plasma inflow on the nightside is modeled throughout the investigated period using data measured at geosynchronous orbit. The modeled Dst index is compared with the observed Dst values corrected for magnetopause and telluric currents. The temporal evolution of the ring current H+ and O+ distribution functions is computed, considering losses due to charge exchange, Coulomb collisions, and ion precipitation. We find that (1) the storm time enhancement of the plasma sheet ion population contributed significantly to the ring current buildup; (2) an additional similar to 12 nT decrease in Dst is achieved when the symmetry line of the plasma convection paths is rotated eastward from the dawn-dusk direction with 3 hours during the first storm; (3) the major loss process is charge exchange, followed by Coulomb collisions and ion precipitation; (4) however, the energy losses due to ion precipitation increase monotonically during the more active periods, reaching the level of Coulomb losses at peak storm intensity. We argue that the losses due to ion precipitation considered in this study are closely related to the enhanced convection electric field, which in our model is parameterized with the planetary Kp index. Correspondingly, we find that (5) there is a very good correlation between the variations in time of this index and the magnitude of the ion precipitation losses. C1 Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. RP Jordanova, VK (reprint author), Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. EM vania.jordanova@unh.edu OI Jordanova, Vania/0000-0003-0475-8743 NR 48 TC 93 Z9 93 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 79 EP 92 DI 10.1029/97JA02367 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900008 ER PT J AU Fairfield, DH Mukai, T Lui, ATY Cattell, CA Reeves, GD Nagai, T Rostoker, G Singer, HJ Kaiser, ML Kokubun, S Lazarus, AJ Lepping, RP Nakamura, M Steinberg, JT Tsuruda, K Williams, DJ Yamamoto, T AF Fairfield, DH Mukai, T Lui, ATY Cattell, CA Reeves, GD Nagai, T Rostoker, G Singer, HJ Kaiser, ML Kokubun, S Lazarus, AJ Lepping, RP Nakamura, M Steinberg, JT Tsuruda, K Williams, DJ Yamamoto, T TI Geotail observations of substorm onset in the inner magnetotail SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID NEAR-EARTH MAGNETOTAIL; PLASMA SHEET; CURRENT DISRUPTION; MAGNETIC-FIELD; MAGNETOSPHERIC SUBSTORMS; ION COMPOSITION; ELECTRIC-FIELD; GROWTH-PHASE; PARTICLE; SIGNATURES AB On April 26, 1995, while Geotail was in the near-equatorial magnetotail at 13 R-E and 2300 LT, a substorm onset occurred that was documented by ground magnetograms, auroral kilometric radiation, and magnetic field and particle data from four spacecraft at and near geosynchronous orbit. Although Geotail was initially outside a greatly thinned current sheet, plasma sheet thickening associated with the substorm dipolarization quickly caused Geotail to move into the plasma sheet where it observed field-aligned earthward moving ions with velocities of 400 km/s. During the subsequent few minutes as the magnetic field became more northward, the velocities increased with particles moving increasingly into the energy range of the energetic particle experiment. These flows culminated with 1-min worth of earthward flow of 2000 km/s that was perpendicular to the northward B field. Such how, probably the largest ever detected at 13 R-E, was confirmed by the observation of an intense de electric field of 50 m V/m (0.3 megavolts/R-E). This large field is probably inductive, caused by reconnection that occurred tailward of the spacecraft, and related to the acceleration processes associated with particle injection at geosynchronous orbit. Energy and magnetic flux conservation arguments suggest that this rapid flow has a small cross-tail dimension of the order of 1 R-E. The data appear to support a simulation of Birn and Hesse [1996] which showed rapid earthward flows from a reconnection line at 23 R-E that caused a tailward expansion of a region of dipolarized flux. Subsequent to the onset, Geotail observed plasma vortices with typical velocities of 50-100 km/s that occurred in a high-beta plasma sheet with a 15-nT northward magnetic field. The vortices were punctuated by occasional flow bursts with velocities up to 400 km/s, one of which was accompanied by a violently varying magnetic field where north/south field components were as large as 30 nT and as small as -8 nT. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Nagoya Univ, STELAB, Toyokawa 442, Japan. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. Tokyo Inst Technol, Tokyo 152, Japan. Univ Tokyo, Dept Earth & Planetary Phys, Bunkyo Ku, Tokyo 113, Japan. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Alberta, Canadian Network Space Res, Edmonton, AB T6G 2J1, Canada. Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. NOAA, Space Environm Ctr, Boulder, CO 80303 USA. RP Fairfield, DH (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RI Reeves, Geoffrey/E-8101-2011; OI Reeves, Geoffrey/0000-0002-7985-8098; Cattell, Cynthia/0000-0002-3805-320X NR 60 TC 73 Z9 75 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 103 EP 117 DI 10.1029/97JA02043 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900010 ER PT J AU Slavin, JA Fairfield, DH Kuznetsova, MM Owen, CJ Lepping, RP Taguchi, S Mukai, T Saito, Y Yamamoto, T Kokubun, S Lui, ATY Reeves, GD AF Slavin, JA Fairfield, DH Kuznetsova, MM Owen, CJ Lepping, RP Taguchi, S Mukai, T Saito, Y Yamamoto, T Kokubun, S Lui, ATY Reeves, GD TI ISTP observations of plasmoid ejection: IMP 8 and Geotail SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TRAVELING COMPRESSION REGIONS; MAGNETIC-FLUX ROPES; DEEP GEOMAGNETIC TAIL; DISTANT MAGNETOTAIL; EARTHS MAGNETOTAIL; ISEE-3 OBSERVATIONS; SUBSTORM; EVOLUTION; SPACECRAFT; RECONNECTION AB IMP 8 and Geotail observations of traveling compression regions (TCRs) and plasmoids, respectively, are used to investigate plasmoid formation and ejection. One year of IMP 8 magnetometer measurements taken during the distant tail phase of the Geotail mission were searched for TCRs, which signal the release of plasmoids down the tail. A total of 10 such intervals were identified. Examination of the Geotail measurements showed that this spacecraft was in the magnetotail for only three of the events. However, in all three cases, clear plasmoid signatures were observed at Geotail. These plasmoids were observed at distances of X = -170 to -197 R-E. The in situ plasma velocities in these plasmoids are found to exceed the time-of-flight speeds between IMP 8 and Geotail suggesting that some further acceleration may have taken place following release. The inferred lengths of these plasmoids, similar to 27-40 R-E, are comparable to the downtail distance of IMP 8. This indicates that TCR at IMP 8 can be caused by plasmoids forming not only earthward but also adjacent to or just tailward of the spacecraft. The closeness of IMP 8 to the point of plasmoid formation is confirmed by the small, similar to 0-3 min, time delays between the TCR perturbation and substorm onset. In two of the plasmoid events, high-speed earthward plasma flows and streaming energetic particles were measured in the plasma sheet boundary layer surrounding the plasmoid along with large positive B-z at the leading edge of the plasmoid suggesting that the core of the plasmoid was "snow plowing" into flux tubes recently closed at an active distant neutral line. In summary, these unique two-point measurements clearly show plasmoid ejection near substorm onset, their rapid movement to the distant tail and their further evolution as they encounter preexisting X lines in the distant tail. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Nagoya Univ, Solar Terr Environm Lab, Aichi 46401, Japan. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. Univ London Queen Mary & Westfield Coll, Astron Unit, London E1 4NS, England. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Electrocommun, Dept Elect Engn, Tokyo, Japan. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA. RP Slavin, JA (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RI Owen, Christopher/C-2999-2008; Kuznetsova, Maria/F-6840-2012; Slavin, James/H-3170-2012; Reeves, Geoffrey/E-8101-2011 OI Owen, Christopher/0000-0002-5982-4667; Slavin, James/0000-0002-9206-724X; Reeves, Geoffrey/0000-0002-7985-8098 NR 56 TC 26 Z9 26 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 119 EP 133 DI 10.1029/97JA02136 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900011 ER PT J AU Kuznetsova, MM Hesse, M Winske, D AF Kuznetsova, MM Hesse, M Winske, D TI Kinetic quasi-viscous and bulk flow inertia effects in collisionless magnetotail reconnection SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID 2-DIMENSIONAL CURRENT SHEETS; THIN CURRENT SHEETS; MAGNETIC RECONNECTION; HYBRID SIMULATIONS; TEARING MODE; PARTICLE SIMULATION; ELECTRON DYNAMICS; X-LINE; PLASMA; CONFIGURATION AB Both electron inertia and nongyrotropic effects were analysed using 2 1/2-dimensional hybrid simulations of collisionless magnetic reconnection. The traditional hybrid approach which treats ions as particles and electrons as an isotropic massless fluid was modified. In the new model the electron mass dependence was introduced both in the expression for the electric field and in the evolution equation of the full electron pressure tensor. This comprehensive hybrid model includes full ion kinetics, incorporates Hall effects, describes the leading terms in electron dynamics responsible for breaking the frozen magnetic flux constraint and allows to consider arbitrary ion/electron temperature and mass ratios. We demonstrate that the kinetic quasi-viscous electron inertia associated with nongyrotropic pressure effects dominates over the electron bulk flow inertia in controlling the structure of the dissipation region around the neutral X line. The reconnection electric field based on the nongyrotropic pressure tends to reduce the current density and to relax gradients in the vicinity of the X line (similar to the localized anomalous viscosity). On the other hand, the reconnection electric field based on electron bulk flow inertia tends to require an increased current density, with gradient scales comparable with the, electron skin depth. The dependence on the ion/electron temperature ratio and on the current carrier also is discussed. An analytical analysis which supports the results of the numerical simulations is also presented. C1 NASA, Goddard Space Flight Ctr, Electrodynam Branch, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Los Alamos Natl Lab, Div Appl Theoret Phys, Los Alamos, NM 87545 USA. RP Kuznetsova, MM (reprint author), Hughes STX Corp, Lanham, MD 20706 USA. RI Hesse, Michael/D-2031-2012; Kuznetsova, Maria/F-6840-2012 NR 46 TC 74 Z9 74 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 199 EP 213 DI 10.1029/97JA02699 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900017 ER PT J AU Crooker, NU Gosling, JT Kahler, SW AF Crooker, NU Gosling, JT Kahler, SW TI Magnetic clouds at sector boundaries SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; CURRENT SHEET; FIELD; TOPOLOGY; EVENTS; MODELS AB Eight of the 14 magnetic clouds in the period August 1978 to February 1982, previously identified in solar wind data by their smooth magnetic field rotations, were encountered at sector boundaries. Most of these differed from those not encountered at sector boundaries in two ways. First, the accompanying counterstreaming electrons, indicating closed magnetic topology, on average spanned intervals more than twice as long as the identified clouds. Second, the field rotations within the identified clouds appear to form part of larger-scale rotations beyond the cloud boundaries that roughly coincide with the counterstreaming electrons. The results suggest that the documented clouds were parts of larger transient structures that are best observed in their entirety at sector boundaries. The data are consistent with spacecraft passages through both the leading and trailing sections of kinematically distorted flux rope loops rooted to the Sun. C1 Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Phillips Lab, GPSS, Hanscom AFB, MA 01731 USA. RP Crooker, NU (reprint author), Boston Univ, Ctr Space Phys, 725 Commonwealth Ave, Boston, MA 02215 USA. EM crooker@buasta.bu.edu NR 29 TC 78 Z9 80 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 1998 VL 103 IS A1 BP 301 EP 306 DI 10.1029/97JA02774 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ714 UT WOS:000071415900026 ER PT J AU Vasco, DW Karasaki, K Myer, L AF Vasco, DW Karasaki, K Myer, L TI Monitoring of fluid injection and soil consolidation using surface tilt measurements SO JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING LA English DT Article ID INVERSION; DEFORMATION; FRACTURE; CALDERA; STRESS AB Temporal variations of surface tilt may be used for the noninvasive monitoring of subsurface volume change. Such volume changes may accompany settlement near structures, the response due to fluid injection or withdrawal, and excavation-related activity. We outline a methodology for using tilt data to estimate volume changes within poroelastic media. The expressions relating subsurface volume change and surface tilt are simple and compact, offering the possibility of real-time monitoring. The inversion of actual tilt data from a site near Raymond, Calif., generates images of fluid withdrawal from a complex fracture zone about 30 m below the surface. Volume changes are confined to an elongated north-south zone in agreement with independent well test data. We have also applied the methodology for the inversion of surface tilt to data from a grout injection experiment in Los Banes. The technique enables us to monitor grout migration through a porous gravel. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Ctr Computat Seismol, Berkeley, CA 94720 USA. RP Vasco, DW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Ctr Computat Seismol, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Vasco, Donald/I-3167-2016 OI Vasco, Donald/0000-0003-1210-8628 NR 25 TC 23 Z9 23 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 1090-0241 J9 J GEOTECH GEOENVIRON JI J. Geotech. Geoenviron. Eng. PD JAN PY 1998 VL 124 IS 1 BP 29 EP 37 DI 10.1061/(ASCE)1090-0241(1998)124:1(29) PG 9 WC Engineering, Geological; Geosciences, Multidisciplinary SC Engineering; Geology GA YM232 UT WOS:000071043000004 ER PT J AU Dykstra, CR Meyer, MW Warnke, DK Karasov, WH Andersen, DE Bowerman, WW Giesy, JP AF Dykstra, CR Meyer, MW Warnke, DK Karasov, WH Andersen, DE Bowerman, WW Giesy, JP TI Low reproductive rates of Lake Superior bald eagles: Low food delivery rates or environmental contaminants? SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE bald eagle; DDE; PCBs; Lake Superior; food; reproductive rates ID GREAT-LAKES; POLYCHLORINATED-BIPHENYLS; SHELL THICKNESS; HERRING-GULLS; PRODUCTIVITY; EGGS; RESIDUES; ABNORMALITIES; PESTICIDE; RECOVERY AB Reproductive rate (productivity) of bald eagles (Haliaeetus leucocephalus) nesting on the shores of Lake Superior was significantly less than that of neighboring eagles nesting in inland Wisconsin (1.0 vs. 1.3 young per breeding attempt, 1989-1993), and at other inland lake/riverine habitats in the Great Lakes Basin. It is possible that the current causes of low productivity on Lake Superior might include exposure to organochlorine contaminants and/or low food availability. Levels of dichloro diphenyl-dichloroethylene (DDE) and total polychlorinated biphenyls (PCBs) in addled eggs and eaglet blood from Lake Superior and inland Wisconsin reference sites were measured. Food delivery rates by parent eagles to nestlings, a possible index to food availability, were quantified at both locations. Concentrations of both DDE and total PCBs in addled eggs declined significantly front 1969 to 1993 (p < 0.001, p = 0.006 respectively), and current concentrations of DDE are at or below the no observable adverse effect level (NOAEL) for reproductive impairment. Concentrations of DDE and total PCBs in plasma were greater in individual nestlings from the shores of Lake Superior than in nestlings at inland locations (18.9 mu g/kg vs. 3.0 mu g/kg DDE, p < 0.001, and 109.1 mu g/kg vs. 42.6 mu g/kg, p = 0.002), but were not correlated to the 5-year average history of productivity for the territory (p > 0.05). Food delivery rates by parent eagles to nestlings at Lake Superior were 56% lower than those to inland nestlings (2.16 vs. 4.87 prey items per day, p = 0.002). Food delivery rates were significantly correlated to average 5-year productivity for inland Wisconsin reference sites (p < 0.001, r(2) = 0.90), although not for Lake Superior sites (p = 0.593). It is concluded that it is likely that the current low productivity of Lake Superior eagles is at least partly attributable to low food availability, but some other factor, possibly PCBs, may also contribute to low productivity. C1 Univ Wisconsin, Dept Wildlife Ecol, Madison, WI 53706 USA. Wisconsin Dept Nat Resources, Bur Integrated Sci Serv, Rhinelander, WI 54501 USA. Univ Minnesota, Dept Fisheries & Wildlife, Cooperat Res Unit, St Paul, MN 55108 USA. US Natl Biol Serv, Minnesota Cooperat Fish & Wildlife Res Unit, St Paul, MN 55108 USA. Eagle Environm Inc, Haslett, MI 48840 USA. Michigan State Univ, Dept Fisheries & Wildlife, Pesticide Res Ctr, E Lansing, MI 48824 USA. Michigan State Univ, Inst Environm Toxicol, E Lansing, MI 48824 USA. RP Dykstra, CR (reprint author), US EPA, Oak Ridge Inst Sci & Educ, NERL, Mail Stop 642,26 W Martin Luther King Dr, Cincinnati, OH 45268 USA. NR 39 TC 30 Z9 30 U1 1 U2 7 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2200 BONISTEEL BLVD, ANN ARBOR, MI 48109-2099 USA SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PY 1998 VL 24 IS 1 BP 32 EP 44 PG 13 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA ZG031 UT WOS:000072958100004 ER PT J AU Alstrom-Rapaport, C Lascoux, M Wang, YC Roberts, G Tuskan, GA AF Alstrom-Rapaport, C Lascoux, M Wang, YC Roberts, G Tuskan, GA TI Identification of a RAPD marker linked to sex determination in the basket willow (Salix viminalis L.) SO JOURNAL OF HEREDITY LA English DT Article ID BULKED SEGREGANT ANALYSIS; DIOECIOUS PLANT; MOLECULAR-GENETICS; ARBITRARY PRIMERS; SILENE-LATIFOLIA; FEMALE FLOWERS; DIFFERENTIATION; MERCURIALIS; POPULUS; GROWTH AB In many dioecious plants, gender influences economic value, breeding schemes, and/or opportunities for commercial use of genetically transformed materials, The objective of this study was to identify molecular markers linked to sex determination loci in the dioecious plant Salix viminalis L, A 4 x 4 factorial mating design was used to identify sex ratios in full-sibling progeny, to generate a working genetics model for segregating sex ratios, and to search for molecular markers linked to sex determination genes, Bulked segregant analysis, utilizing 380 arbitrary decamer primers to generate randomly amplified polymorphic DNA (RAPD) products was initially applied to progeny sets from 3 of the 16 full-sibling families, Of the 1080 RAPD bands examined, only a single 560 bp band was shown to be linked to a sex determination locus, The same 560 bp band occurred in three additional full-sibling families and was present In one female parent and one male parent involved in the factorial mating design, This marker, UBC354(560), is biparentally inherited, is associated with femaleness in certain genetic backgrounds, and is linked to allele Al in the proposed two-locus epistatic genetic model of sex determination for S. viminalis. Southern blots confirmed marker homology among progeny and parents used in this study. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Swedish Univ Agr Sci, Dept Plant Breeding, S-75007 Uppsala, Sweden. Swedish Univ Agr Sci, Dept Forest Genet, Uppsala, Sweden. RP Tuskan, GA (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Tuskan, Gerald/A-6225-2011 OI Tuskan, Gerald/0000-0003-0106-1289 NR 25 TC 79 Z9 85 U1 0 U2 3 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-1503 J9 J HERED JI J. Hered. PD JAN-FEB PY 1998 VL 89 IS 1 BP 44 EP 49 DI 10.1093/jhered/89.1.44 PG 6 WC Evolutionary Biology; Genetics & Heredity SC Evolutionary Biology; Genetics & Heredity GA YX073 UT WOS:000072003700007 ER PT J AU Tucker, MD Barton, LL Thomson, BM AF Tucker, MD Barton, LL Thomson, BM TI Reduction of Cr, Mo, Se and U by Desulfovibrio desulfuricans immobilized in polyacrylamide gels SO JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY LA English DT Article DE immobilized cells; Desulfovibrio; dissimilatory metal reduction ID DISSIMILATORY METAL REDUCTION; URANIUM; BIOREMEDIATION; SULFATE AB Intact cells of Desulfovibrio desulfuricans, immobilized in polyacrylamide gel, removed Cr, Mo, Se and U from solution by enzymatic-mediated reduction reactions, Lactate or H-2 served as the electron donor and the oxidized Cr(VI), Mo(VI), Se(VI) and U(VI) served as electron accepters, Reduction of the oxidized metal species resulted in the precipitation of solid phases of the metals, Metal removal efficiencies of 86-96% were achieved for initial concentrations of 1 mM Mo, Se, and U and 0.5 mM Cr, Insoluble metal phases accumulated on both the surface and the interior of the polyacrylamide gel, In column tests conducted for U removal, effluent concentrations less than 20 mu g L-1 were achieved with initial concentrations of 5 mg L-1 and 20 mg L-1 U and residence times from 25-37 h, The enzymatic reduction of Cr, Mo, Se, and U by immobilized cells of D. desulfuricans may be a practical method for removing these metals from solution in a biological reactor. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Civil Engn, Albuquerque, NM 87131 USA. RP Tucker, MD (reprint author), Sandia Natl Labs, 1515 Eubank SE, Albuquerque, NM 87123 USA. NR 20 TC 84 Z9 89 U1 2 U2 12 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE RG21 6XS, HAMPSHIRE, ENGLAND SN 1367-5435 J9 J IND MICROBIOL BIOT JI J. Ind. Microbiol. Biotechnol. PD JAN PY 1998 VL 20 IS 1 BP 13 EP 19 DI 10.1038/sj.jim.2900472 PG 7 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA YZ989 UT WOS:000072315900002 PM 9565467 ER PT J AU Chapatwala, KD Babu, GRV Vijaya, OK Kumar, KP Wolfram, JH AF Chapatwala, KD Babu, GRV Vijaya, OK Kumar, KP Wolfram, JH TI Biodegradation of cyanides, cyanates and thiocyanates to ammonia and carbon dioxide by immobilized cells of Pseudomonas putida SO JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY LA English DT Article DE biodegradation; cyanides; cyanates; thiocyanates; immobilization; bioreactor; alginate beads; Pseudomonas putida ID MICROBIAL-CELLS; DEGRADATION; FLUORESCENS; CONVERSION; ENZYME; PHENOLS; GROWTH AB Pseudomonas putida utilizes cyanide as the sole source of carbon and nitrogen, Agar, alginate, and carrageenan were screened as the encapsulating matrices for P. putida. Alginate-immobilized cells of P. putida degraded sodium cyanide (NaCN) more efficiently than non-immobilized cells or cells immobilized in agar or carrageenan. The end products of biodegradation of cyanide were identified as ammonia (NH3) and carbon dioxide (CO2), These products changed the medium pH, In bioreactors, the rate of cyanide degradation increased with an increase in the rate of aeration. Maximum utilization of cyanide was observed at 200 ml min(-1) of aeration, Immobilized cells of P. putida degraded cyanides, cyanates and thiocyanates to NH3 and CO2. Use of Na[C-14]-CN showed that 70% of carbon of Na[C-14]-CN was converted into (CO2)-C-14 and only 10% was associated with the cell biomass, The substrate-dependent kinetics indicated that the K-m and V-max values of P. putida for the substrate, NaCN were 14 mM and 29 nmol of oxygen consumed mg protein(-1) min(-1) respectively. C1 Selma Univ, Div Nat Sci, Selma, AL 36701 USA. Univ Mississippi, Med Ctr, Dept Med, Jackson, MS 39216 USA. Lockheed Idaho Technol Co, Biotechnol, Idaho Falls, ID 83404 USA. RP Chapatwala, KD (reprint author), Selma Univ, Div Nat Sci, Selma, AL 36701 USA. NR 35 TC 26 Z9 29 U1 0 U2 3 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE RG21 6XS, HAMPSHIRE, ENGLAND SN 1367-5435 J9 J IND MICROBIOL BIOT JI J. Ind. Microbiol. Biotechnol. PD JAN PY 1998 VL 20 IS 1 BP 28 EP 33 DI 10.1038/sj.jim.2900469 PG 6 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA YZ989 UT WOS:000072315900004 PM 9523454 ER PT J AU Cantor, RM Blanche, PJ Rotter, JI Davis, R Lanning, CD Fernstrom, HS Rawlings, RS Holl, LG Orr, JE Scheuner, MT Wen, PZ Lusis, AJ Krauss, RM AF Cantor, RM Blanche, PJ Rotter, JI Davis, R Lanning, CD Fernstrom, HS Rawlings, RS Holl, LG Orr, JE Scheuner, MT Wen, PZ Lusis, AJ Krauss, RM TI Linkage of low density lipoprotein (LDL) subclass phenotypes to candidate gene loci in sibling pairs on high-fat (HF) and low-fat (LF) diets. SO JOURNAL OF INVESTIGATIVE MEDICINE LA English DT Meeting Abstract C1 Univ Calif Los Angeles, Los Angeles, CA USA. Cedars Sinai Res Inst, Div Med Genet, Los Angeles, CA USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Mol Med, Berkeley, CA USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU SLACK INC PI THOROFARE PA 6900 GROVE RD, THOROFARE, NJ 08086 USA SN 1081-5589 J9 J INVEST MED JI J. Invest. Med. PD JAN PY 1998 VL 46 IS 1 BP 117A EP 117A PG 1 WC Medicine, General & Internal; Medicine, Research & Experimental SC General & Internal Medicine; Research & Experimental Medicine GA YU124 UT WOS:000071684700624 ER PT J AU Hadley, GR AF Hadley, GR TI Low-truncation-error finite difference equations for photonics simulation I: Beam propagation SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article ID TRANSPARENT BOUNDARY-CONDITION; DOUGLAS SCHEME; OPERATORS AB A methodology is presented that allows the derivation of low-truncation-error finite difference equations for photonics simulation. This methodology is applied to the case of wide-angle beam propagation in two dimensions, resulting in finite difference equations for both TE and TM polarization that are quasi-fourth-order accurate even in the presence of interfaces between dissimilar dielectrics. This accuracy is accomplished without an appreciable increase in numerical overhead and is concretely demonstrated for two test problems having known solutions, These finite difference equations facilitate an approach to the ideal of grid-independent computing and should allow the simulation of relevant photonics devices on personal computers. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hadley, GR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 11 TC 42 Z9 42 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD JAN PY 1998 VL 16 IS 1 BP 134 EP 141 DI 10.1109/50.654995 PG 8 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA YP896 UT WOS:000071326900019 ER PT J AU Hadley, GR AF Hadley, GR TI Low-truncation-error finite difference equations for photonics simulation II: Vertical-cavity surface-emitting lasers SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article ID MODEL AB The basic approach outlined in the previous article is applied to the difficult problem of computing the optical modes of a vertical-cavity surface-emitting laser. The formulation utilizes a finite difference equation based upon the lowest order term of an infinite series solution of the scalar Helmholtz Equation in a local region. This difference equation becomes exact in the one-dimensional (1-D) limit, and is thus ideally suited for nearly 1-D devices such as vertical-cavity lasers. The performance of the resulting code is tested on both a simple cylindrical cavity with known solutions and an oxide-confined vertical-cavity laser structure, and the results compared against second-order-accurate code based upon Crank-Nicolson differencing. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hadley, GR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 12 TC 21 Z9 21 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD JAN PY 1998 VL 16 IS 1 BP 142 EP 151 DI 10.1109/50.654996 PG 10 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA YP896 UT WOS:000071326900020 ER PT J AU Ishikiriyama, K Pyda, M Zhang, GE Forschner, T Grebowicz, J Wunderlich, B AF Ishikiriyama, K Pyda, M Zhang, GE Forschner, T Grebowicz, J Wunderlich, B TI Heat capacity of poly-p-dioxanone SO JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS LA English DT Article ID DIFFERENTIAL SCANNING CALORIMETRY; LINEAR ALIPHATIC POLYOXIDES; THERMODYNAMIC PROPERTIES; GLASS-TRANSITION; MACROMOLECULES; POLYESTERS; POLYETHYLENE; TEMPERATURE; POLYAMIDES; BEHAVIOR AB The heat capacity of poly-p-dioxanone (PPDX), (CH2-CH2-O-CH2-COO-)(x), was determined using both differential scanning calorimetry (DSC) and temperature-modulated DSC (TMDSC) from 200 K to 430 K. Based on the new data and literature data, the heat capacity of the solid state was analyzed using an approximate group vibrational spectrum and skeletal vibrations. The 10 skeletal vibrational modes are well represented by a Tarasov function with theta temperatures of theta(1) = 478.7 K and theta(3) = 50.4 K. The heat capacity of the liquid was fitted to a linear function, C-p(liquid) = 0.1484 T + 144.3 in units of J K-1 mol(-1), which is close to the sum of equations developed earlier for the liquids of poly(oxyethylene) and polyglycolide. The change in heat capacity of amorphous PPDX at the glass transition temperature (264 K) is 69.9 J K-1 mol(-1), and the heat of fusion for perfect crystals at the melting temperature (approximate to 400 K) is 14.4 kJ mol(-1). The integral thermodynamic functions were derived, and the residual entropy of the glass at 0 K, determined from these functions, is extrapolated as 13.4 J K-1 mol(-1) (or 2.7 J K-1 mol(-1) per chain atom). C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Chem & Analyt Sci Div, Oak Ridge, TN 37831 USA. Shell Chem Co, Houston, TX 77251 USA. RP Ishikiriyama, K (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 38 TC 69 Z9 73 U1 2 U2 19 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0022-2348 J9 J MACROMOL SCI PHYS JI J. Macromol. Sci.-Phys. PY 1998 VL B37 IS 1 BP 27 EP 44 DI 10.1080/00222349808220453 PG 18 WC Polymer Science SC Polymer Science GA YW729 UT WOS:000071966900003 ER PT J AU Brunner, E Seydoux, R Haake, M Pines, A Reimer, JA AF Brunner, E Seydoux, R Haake, M Pines, A Reimer, JA TI Surface NMR using laser-polarized (129)Xe under magic angle spinning conditions SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article DE laser-polarized (129)Xe; nuclear magnetic resonance; magic angle spinning; solid surfaces; spin polarization induced nuclear Overhauser effect ID IN-SITU NMR; SOLID CATALYSTS; XENON; PROBE; NUCLEI; FLOW AB NMR signals of surface nuclei of solids may be enhanced by the transfer of spin polarization from laser-polarized noble gases. Until now such experiments have not been feasible under conditions of magic angle spinning. In the present contribution it is shown that laser-polarized (129)Xe can be inserted into a spinning rotor under continuous-flow conditions using helium as a carrier gas. Effective adsorption of xenon on the sample occurs at temperatures of about 163-173 K making possible the observation of a spin polarization induced nuclear Overhauser effect (SPINOE) from the laser-polarized (129)Xe to surface (1)H nuclei of SiO(2) (AEROSIL300). This technique opens the way to selectively enhanced high-resolution multinuclear surface NMR experiments. (C) 1998 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Brunner, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM ebrunner@dirac.cchem.berkeley.edu NR 21 TC 48 Z9 49 U1 1 U2 13 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD JAN PY 1998 VL 130 IS 1 BP 145 EP 148 DI 10.1006/jmre.1997.1296 PG 4 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA ZC833 UT WOS:000072622700022 ER PT J AU Ikeda, H Takahashi, M Fernandez-Baca, JA Nicklow, RM AF Ikeda, H Takahashi, M Fernandez-Baca, JA Nicklow, RM TI Neutron study of fracton excitations in percolating antiferromagnets SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE fractals magnetic excitations; neutron scattering; excitations; percolation AB We report the results of an inelastic neutron scattering experiment on nearly percolating Heisenberg antiferromagnets (RbMncMg1-cF3), in which the Mn concentrations (c = 0.31, 0.34 and 0.39) are very close to the percolation threshold (c(p) = 0.312). A broad-peak superimposed on Ising-cluster excitations was observed throughout the Brillouin zone. The intensity of a broad peak increased on approaching the percolation threshold. The origin of this broad peak is attributed to the excitation of fractons in a percolating network. (C) 1998 Elsevier Science B.V. All rights reserved. C1 High Energy Accelerator Res Org, Neutron Sci Lab, Tsukuba, Ibaraki 305, Japan. Univ Tsukuba, Inst Phys Appl, Tsukuba, Ibaraki 305, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ikeda, H (reprint author), High Energy Accelerator Res Org, Neutron Sci Lab, Oho 1-1, Tsukuba, Ibaraki 305, Japan. EM hikeda@kekvax.kek.jp RI Fernandez-Baca, Jaime/C-3984-2014 OI Fernandez-Baca, Jaime/0000-0001-9080-5096 NR 6 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 139 EP 140 DI 10.1016/S0304-8853(97)00334-X PN 1 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ517 UT WOS:000072262000053 ER PT J AU Montenegro, FC Lima, KA Torikachvili, MS Lacerda, AH AF Montenegro, FC Lima, KA Torikachvili, MS Lacerda, AH TI Phase diagram of the random-field Ising system Fe0.60Zn0.40F2 at intense fields SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE magnetic phase diagrams; random fields; spin-glass behavior ID NEUTRON-SCATTERING; HEAT-CAPACITY; X-RAY; MODEL; MAGNETIZATION AB The critical and irreversibility phase boundaries of the d = 3 dilute uniaxial antiferromagnet Fe0.60Zn0.40F2 have been determined under strong magnetic fields by magnetization measurements. Our data reveal that the random-held-induced glassy phase, previously observed in the upper part of the (H, T) phase diagram for highly diluted samples (Fe concentration x congruent to 0.3), is extensive to higher values of x. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Fed Pernambuco, Dept Fis, BR-50670901 Recife, PE, Brazil. San Diego State Univ, Dept Phys, San Diego, CA 92182 USA. Univ Calif Los Alamos Natl Lab, Pulse Facil, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. RP Montenegro, FC (reprint author), Univ Fed Pernambuco, Dept Fis, BR-50670901 Recife, PE, Brazil. EM fcm@df.ufpe.br NR 9 TC 12 Z9 12 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 145 EP 146 DI 10.1016/S0304-8853(97)00313-2 PN 1 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ517 UT WOS:000072262000056 ER PT J AU Slanic, Z Belanger, DP Fernandez-Baca, JA AF Slanic, Z Belanger, DP Fernandez-Baca, JA TI Random-field critical scattering at high-magnetic concentration in the Ising antiferromagnet Fe0.93Zn0.O7F2 SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE critical phenomena; dilute antiferromagnet; neutron scattering critical; random fields ID CRITICAL-BEHAVIOR; NEUTRON-SCATTERING; MODEL; SYSTEM AB The high-magnetic concentration Ising antiferromagnet Fe0.93Zn0.07F2 does not exhibit the severe critical scattering hysteresis at low temperatures observed in all the lower concentration samples studied. The system, therefore, provides equilibrium neutron scattering line shapes suitable for determining random-held Ising model critical behavior. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Belanger, DP (reprint author), Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. EM dave@dave.ucsc.edu RI Fernandez-Baca, Jaime/C-3984-2014 OI Fernandez-Baca, Jaime/0000-0001-9080-5096 NR 9 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 171 EP 172 DI 10.1016/S0304-8853(97)00333-8 PN 1 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ517 UT WOS:000072262000069 ER PT J AU Bao, W Broholm, C Aeppli, G Carter, SA Dai, P Frost, CD Honig, JN Metcalf, P AF Bao, W Broholm, C Aeppli, G Carter, SA Dai, P Frost, CD Honig, JN Metcalf, P TI Magnetic correlations in a classic Mott system SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE Mott localization; spin density wave; itinerant electrons - antiferromagnetism; orbital ordering; paramagnetic fluctuations ID SPIN-DENSITY-WAVE; ITINERANT ANTIFERROMAGNETISM; DOPED V2O3; SUPERCONDUCTIVITY; TEMPERATURE; PHASE AB The metal-insulator transition in pure and doped V2O3 causes a fundamental change in its magnetism. While the antiferromagnetic insulator (AFI) is a Heisenberg localized spin system, the antiferromagnetism in the strongly correlated metal is determined by a Fermi surface instability. Paramagnetic fluctuations in the metal and insulator represent similar spatial spin correlations, but are unrelated to the long-range order in the AFI. The phase transition to the AFI induces an abrupt switching of magnetic correlations to a different magnetic wave vector. The AFI transition, therefore, is not a conventional spin order-disorder transition. Instead it is accounted for by an ordering in the occupation of the two degenerate d-orbitals at the Fermi level. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. NEC, Princeton, NJ 08540 USA. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Rutherford Appleton Lab, ISIS, Didcot OX11 0QX, Oxon, England. Purdue Univ, W Lafayette, IN 47907 USA. RP Bao, W (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Broholm, Collin/E-8228-2011; Dai, Pengcheng /C-9171-2012; Bao, Wei/E-9988-2011 OI Broholm, Collin/0000-0002-1569-9892; Dai, Pengcheng /0000-0002-6088-3170; Bao, Wei/0000-0002-2105-461X NR 34 TC 6 Z9 6 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 283 EP 286 DI 10.1016/S0304-8853(97)00607-0 PN 1 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ517 UT WOS:000072262000116 ER PT J AU Coldea, R Tennant, DA Cowley, RA McMorrow, DF Dorner, B Tylczynski, Z AF Coldea, R Tennant, DA Cowley, RA McMorrow, DF Dorner, B Tylczynski, Z TI The phase diagram of a quasi-1D S=1/2 antiferromagnet SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE antiferromagnetism - quantum; spinons; helimagnetic order ID MAGNETIC-FIELD; CHAIN AB The magnetic structure and excitations of the quasi-one-dimensional S = 1/2 Heisenberg antiferromagnet (HAF) Cs2CuCl4 have been measured using neutron scattering. At low temperatures and zero field the spins are arranged in a cycloid close to the (b,c) plane and the ordering is incommensurate along the chain direction. When a held B > 1.66 T is applied along the c-axis a transition occurs to a phase in which the order disappears and the excitations are in agreement with the theoretical predictions for the quantum 1D S = 1/2 HAF chain. When the field is applied along the a-axis the incommensurate ordering persists up to the critical field approximate to 8.5 T, above which the system is fully aligned by the field. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Riso Natl Lab, Dept Solid State Phys, DK-4000 Roskilde, Denmark. Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France. Inst Phys, PL-61614 Poznan, Poland. RP Cowley, RA (reprint author), Univ Oxford, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. RI McMorrow, Desmond/C-2655-2008; Tennant, David/Q-2497-2015 OI McMorrow, Desmond/0000-0002-4947-7788; Tennant, David/0000-0002-9575-3368 NR 8 TC 7 Z9 7 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 659 EP 660 DI 10.1016/S0304-8853(97)00718-X PN 1 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ517 UT WOS:000072262000287 ER PT J AU Bruck, E van Streepen, T Duijn, HGM Haanappel, EG de Boer, FR Buschow, KHJ AF Bruck, E van Streepen, T Duijn, HGM Haanappel, EG de Boer, FR Buschow, KHJ TI Magnetic and transport properties of MnPtAl1-xGax compounds SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE antiferromagnetism; metamagnetism; substitution effects AB We have studied the effect of Ga substitution on the magnetic and transport properties of MnPtAl1-xGax compounds with x = 0, 0.05, 0.1, 0.15 and 0.2. With increasing Ga concentration, we find a rather weak linear reduction of the Neel temperature. However, the metamagnetic field associated with the field-induced ferromagnetic alignment is strongly reduced. The results are discussed in the framework of competing Mn-Mn interactions. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Amsterdam, Van der Waals Zeeman Inst, NL-1018 XE Amsterdam, Netherlands. Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. RP Bruck, E (reprint author), Univ Amsterdam, Van der Waals Zeeman Inst, Valckenierstr 65, NL-1018 XE Amsterdam, Netherlands. EM bruck@phys.uva.nl RI Bruck, Ekkes/E-3365-2014 NR 4 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 767 EP 768 DI 10.1016/S0304-8853(97)00731-2 PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ519 UT WOS:000072262200004 ER PT J AU de Chatel, PF Prokes, K Nakotte, H Purwanto, A Sechovsky, V Havela, L Bruck, E Robinson, RA de Boer, FR AF de Chatel, PF Prokes, K Nakotte, H Purwanto, A Sechovsky, V Havela, L Bruck, E Robinson, RA de Boer, FR TI Anisotropic exchange interactions in UNiGe SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE anisotropy - magnetic; magnetic interactions; antiferromagnetism; actinide compounds ID TRANSPORT-PROPERTIES; UTX COMPOUNDS AB UNiGe crystallizing in the orthorhombic TiNiSi-type of structure orders magnetically below T-N = 50 K with an additional magnetic phase transition at 42 K. Both structures (below 42 K commensurate antiferromagnetic, between 42 K and T-N incommensurate) are non-collinear with a significant a-axis component (mu(x) = 0.35 mu(B)/U at 20 K). The magnetic properties are highly anisotropic both in the ordered and the paramagnetic state. There are two metamagnetic transitions both with the field applied along the b- and the c-axis. While the magnetic structure above the second metamagnetic transition is forced ferromagnetic for both field orientations, for the field applied along the a-axis the magnetization curve at 4.2 K is linear up to 38 T and no change in magnetic structure is observed. UNiGe provides strong evidence for anisotropic exchange interaction. The fact that the a-axis component cannot be aligned by the highest magnetic field used indicates that the antiferromagnetic interaction is much stronger between the a-axis components than between the others. This behaviour cannot be due to single-ion anisotropy because in that case the free energy does not depend on the sign of the a-axis component. (C) 1998 by Elsevier Science B.V. All rights reserved. C1 Univ Amsterdam, Van der Waals Zeeman Inst, NL-1018 XE Amsterdam, Netherlands. Univ Calif Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. Charles Univ, Dept Met Phys, CR-12116 Prague, Czech Republic. RP de Chatel, PF (reprint author), Univ Amsterdam, Van der Waals Zeeman Inst, Kruislaan 403, NL-1018 XE Amsterdam, Netherlands. RI Bruck, Ekkes/E-3365-2014; Sechovsky, Vladimir/A-5256-2008 OI Sechovsky, Vladimir/0000-0003-1298-2120 NR 7 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 785 EP 786 DI 10.1016/S0304-8853(97)00737-3 PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ519 UT WOS:000072262200013 ER PT J AU Fisher, RA Wright, DA Radhakrishna, P Luce, JL Stacy, AM Phillips, NE AF Fisher, RA Wright, DA Radhakrishna, P Luce, JL Stacy, AM Phillips, NE TI The specific heat of LaCu2O4 and NdCu2O4 in fields to 7 T SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE specific heat; entropy; antiferromagnetism; spin waves; magnetic ordering AB Specific heats for LaCu2O4 and NdCu2O4, with two inequivalent Cu sites [Cu2+ (S = 1/2, magnetic) and Cu3+ (S = 1, nonmagnetic)], were measured in fields to 7 T. The field-dependent ordering of the Cu2+ had an associated field-independent entropy of 0.29R In 2 instead of the expected R in 2. NdCu2O4 had an additional specific-heat anomaly for Nd3+ and gamma(H)T terms nearly two orders of magnitude greater than those for LaCu2O4. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Low Temp Lab, Berkeley, CA 94720 USA. RP Fisher, RA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Low Temp Lab, Berkeley, CA 94720 USA. NR 4 TC 6 Z9 6 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 787 EP 788 DI 10.1016/S0304-8853(97)00307-7 PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ519 UT WOS:000072262200014 ER PT J AU Merrin, J Fudamoto, Y Kojima, KM Larkin, M Luke, GM Nachumi, B Uemura, YJ Kondo, S Johnston, DC AF Merrin, J Fudamoto, Y Kojima, KM Larkin, M Luke, GM Nachumi, B Uemura, YJ Kondo, S Johnston, DC TI Muon spin relaxation measurements of LiV2O4 SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE muon spin relaxation; frustration; transition metal oxides; heavy fermions AB We report low-temperature (20 mK-5 K) muon spin relaxation (mu SR) measurements of the geometrically spin-frustrated LiV2O4. We find that the spin dynamics of the ground state are very sensitive to magnetic impurities of the specimens. We discuss the similarities of the ground state with spin glasses. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Columbia Univ, Dept Phys, New York, NY 10027 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Merrin, J (reprint author), Columbia Univ, Dept Phys, 538 W 120th St, New York, NY 10027 USA. RI Luke, Graeme/A-9094-2010; OI Luke, Graeme/0000-0003-4762-1173 NR 5 TC 13 Z9 13 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 799 EP 800 DI 10.1016/S0304-8853(97)00635-5 PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ519 UT WOS:000072262200019 ER PT J AU Nieuwenhuys, GJ Suellow, S Menovsky, AA Mydosh, JA Heffner, RH Le, LP MacLaughlin, DE Bernal, OO Schenck, A AF Nieuwenhuys, GJ Suellow, S Menovsky, AA Mydosh, JA Heffner, RH Le, LP MacLaughlin, DE Bernal, OO Schenck, A TI mu+SR in the random bond spin glass URh2Ge2 SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE muon spin rotation; spin glass; heavy fermion; magnetic ordering AB As-cast single crystals of URh2Ge2 are heavy fermions which also behave as random-bond spin glasses. This is unusual among compounds with a translationally invariant lattice of magnetic ions. We have carried out mu(+)SR experiments on a single crystal in both the as-grown and annealed states. Strong spin depolarization is observed when the temperature is lowered below 15 K, but no spontaneous precession has been found. Experiments in a longitudinal field showed this relaxation to be of a static origin. This indicates the presence of large and random dipolar fields at the muon site, thus of large and randomly ordered magnetic moments. The depolarization function can be described by a stretched exponential, characteristic for spin glasses. Experiments with different angles between the crystalline axes and the initial mu(+) spin failed to show any anisotropy of the depolarization rate. Also, the effect of annealing (one week at 900 degrees C) is very small. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Calif State Univ Los Angeles, Los Angeles, CA 90032 USA. Leiden Univ, Kamerlingh Onnes Lab, NL-2300 RA Leiden, Netherlands. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Riverside, Riverside, CA 92521 USA. ETH Zurich, PSI, Inst Particle Phys, CH-5232 Villigen, Switzerland. RP Nieuwenhuys, GJ (reprint author), Leiden Univ, Kamerlingh Onnes Lab, POB 9506, NL-2300 RA Leiden, Netherlands. EM nieuwen@rulkol.leidenuniv.nl NR 8 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 803 EP 804 DI 10.1016/S0304-8853(97)00735-X PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ519 UT WOS:000072262200021 ER PT J AU Gordon, JE Fisher, RA Jia, YX Phillips, NE Reklis, SF Wright, DA Zettl, A AF Gordon, JE Fisher, RA Jia, YX Phillips, NE Reklis, SF Wright, DA Zettl, A TI Specific heat of Nd(1-x)SrxMnO3 SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE specific heat; entropy; magneto-resistance; phase transitions; itinerant electrons ID TRANSPORT-PROPERTIES AB The specific heat (C) of the colossal magnetoresistance material Nd0.67Sr0.33MnO3 was measured for 0.35 < T < 280 K and 0 less than or equal to H less than or equal to 9 T. Estimates were made of contributions to C from the hyperfine interactions, the lattice, Nd3+ magnetic ordering, ferromagnetic ordering of the Mn ions near T-c approximate to 205 K, and a low-T gamma T term. The entropy associated with the last three terms is essentially equal to that expected for the ordering of the Nd and Mn moments. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Amherst Coll, Dept Phys, Amherst, MA 01002 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Gordon, JE (reprint author), Amherst Coll, Dept Phys, Amherst, MA 01002 USA. RI Zettl, Alex/O-4925-2016 OI Zettl, Alex/0000-0001-6330-136X NR 8 TC 19 Z9 19 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 856 EP 857 DI 10.1016/S0304-8853(97)00305-3 PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ519 UT WOS:000072262200044 ER PT J AU Baranov, NV Markin, PE Nakotte, H Lacerda, A AF Baranov, NV Markin, PE Nakotte, H Lacerda, A TI Magnetic and transport properties of Tb3Co studied on single crystals SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE phase transitions; magnetoresistance; phase diagram AB The orthorhombic Tb3Co compound exhibits both, ferromagnetic and antiferromagnetic behavior below the critical temperature T-t approximate to 72 K as evidenced by metamagnetic transitions along the a- and b-axis and ferromagnetic magnetization process along the c-axis. In the temperature interval between T-t and the Neel temperature T-N approximate to 82 K field-induced transitions along all three axes are observed. The metamagnetic transitions are accompanied by a significant magnetoresistance effect. In order to study the magnetic hysteresis in Tb3Co the (R1-xYx)(3)Co (R = Tb, Gd) compounds have been also investigated. The Tb3Co single crystal has permanent magnet properties along the c-axis with the highest energy product up to 140 MG Oe at T less than or equal to 4.2 K. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Ural State Univ, Inst Phys & Appl Math, Ekaterinburg 620083, Russia. Univ Calif Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos Facil, Los Alamos, NM 87545 USA. RP Baranov, NV (reprint author), Ural State Univ, Inst Phys & Appl Math, Ekaterinburg 620083, Russia. RI Markin, Pavel/K-7088-2013; Baranov, Nikolai/J-5042-2013 OI Markin, Pavel/0000-0002-9537-2303; Baranov, Nikolai/0000-0002-9720-5314 NR 5 TC 9 Z9 9 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 1133 EP 1134 DI 10.1016/S0304-8853(97)00288-6 PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ519 UT WOS:000072262200170 ER PT J AU Pasternak, MP Amanowicz, M Milner, AP Rozenberg, GK Taylor, RD Hearne, GR Brister, KE AF Pasternak, MP Amanowicz, M Milner, AP Rozenberg, GK Taylor, RD Hearne, GR Brister, KE TI High-pressure p-p band closure of the negative-triangle Sr2FeO4 perovskite SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE high pressure; Mossbauer spectroscopy; X-ray diffraction; phase transitions - metal-insulator AB Recent analyses of X-ray photoemission (XPS) spectroscopy performed in some high-valence transition metal (TM) oxide insulators have implied the existence of band gaps of the p-p type, corresponding to d(n)L + d(n)L --> d(n) + d(n)L(2) charge fluctuations. This band gap is neither the d-d Mott-Hubbard nor the pd charge-transfer type common to many insulating TM compounds. Thus, it is expected that upon metallization the magnetic moments and ordering will be barely affected since the d-bands are not directly involved in the band-gap closure. We have investigated high-pressure magnetic, structural, and transport properties of Sr2FeO4 (Fe4+), an antiferromagnetic (T-N = 60 K) insulator, using diamond anvil cells up to P = 30 GPa. With the increasing pressure a significant increase in the conductance (sigma) is observed and at P-M = 19 GPa the compound metallizes as concluded from the onset of a negative slope of sigma(T). Magnetic studies performed with Fe-57 Mossbauer spectroscopy showed no evidence of a magnetic moment collapse at P-M and beyond, up to P = 30 GPa. No structural phase transition occurs up to 30 GPa. The coexistence of magnetic moments and metallic state in this oxide is clear evidence of an intra-ligand p-p gap as proposed by the XPS data analyses. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Univ Calif Los Alamos Natl Lab, Div Mat Sci, Los Alamos, NM 87545 USA. Univ Witwatersrand, Dept Phys, ZA-2050 Johannesburg, South Africa. Cornell Univ, Wilson Lab, CHESS, Ithaca, NY 14853 USA. RP Pasternak, MP (reprint author), Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. NR 6 TC 0 Z9 0 U1 2 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 1377 EP 1378 DI 10.1016/S0304-8853(97)00610-0 PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ519 UT WOS:000072262200275 ER PT J AU Ling, MF Staunton, JB Johnson, DD Pinski, FJ AF Ling, MF Staunton, JB Johnson, DD Pinski, FJ TI Magnetic correlations in gamma-Mn and a Mn-10 at%Cu alloy SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism CY JUL 27-AUG 01, 1997 CL CAIRNS, AUSTRALIA DE antiferromagnetic correlations; exchange splitting; local moments in disordered alloys; Neel temperature ID SHORT-RANGE ORDER; 1ST-PRINCIPLES THEORY; PARAMAGNETIC ALLOYS AB We have carried out first-principles calculations of the paramagnetic susceptibilities of gamma-Mn and a Mn-10 at%Cu solid solution in which the paramagnetic state is modelled in terms of fluctuating 'local moments'. We find that both systems exhibit clear antiferromagnetic correlations. These an significantly stronger in the alloy. We show that this is caused by Cu impurity states reducing the dispersion of some Mn d-states. This increases the magnitude of the Mn local moments which interact antiferromagnetically. The Neel temperature of the gamma-Mn is found to be 267 K, whereas that of Mn-10 at%Cu is 382 K. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Monash Univ, Dept Phys, Clayton, Vic 3168, Australia. Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Sandia Natl Labs, Computat Mat Sci Dept, Livermore, CA 94551 USA. Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. RP Ling, MF (reprint author), Monash Univ, Dept Phys, Clayton, Vic 3168, Australia. NR 7 TC 5 Z9 5 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD JAN PY 1998 VL 177 BP 1399 EP 1400 DI 10.1016/S0304-8853(97)00847-0 PN 2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA YZ519 UT WOS:000072262200286 ER PT J AU Chan, K King, C Wright, P AF Chan, K King, C Wright, P TI COMPASS: Computer oriented materials, processes, and apparatus selection system SO JOURNAL OF MANUFACTURING SYSTEMS LA English DT Article DE process selection; manufacturing planning; CAPP; concurrent engineering ID PRODUCT; DESIGN AB Today's competitive manufacturing environment requires a shortened product development time. Although great emphasis has been placed on concurrent engineering, it is still a challenge for engineers to bridge the gap between design and manufacturing. This paper proposes a new approach to an emerging concept, Meta Planning, which brings manufacturing issues upstream by generating timely and appropriate feedback to design engineers. While a product or feature is being designed, all feasible downstream manufacturing processes can be compared. A meta planner can be integrated into existing CAD/CAPP/CAM systems to automate high-level process planning such that heterogeneous processes can be organized into a coherent plan. COMPASS (Computer Oriented Materials, Processes, and Apparatus Selection System), developed as a meta planner, has the basic framework to provide essential information regarding production cost, cycle time, and product quality for all of the candidate processes. It is a tool that helps design engineers identify potential manufacturing problems in the earlier stages of product development. Three different hole-making process models are implemented in COMPASS to illustrate the mechanism that analyzes and compares different manufacturing processes. Close interaction between design parameters and manufacturing performance for selected processes is demonstrated through a detailed case study involving a single feature. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Univ Calif Berkeley, Management Technol Program, Berkeley, CA 94720 USA. NYU, Courant Inst Math Sci, New York, NY USA. NYU, Robot & Mfg Res Lab, New York, NY USA. RP Chan, K (reprint author), VLSI Inc, San Jose, CA 95131 USA. NR 18 TC 6 Z9 7 U1 0 U2 1 PU SOC MANUFACTURING ENGINEERS PI DEARBORN PA ONE SME DRIVE, PO BOX 930, DEARBORN, MI 48121-0930 USA SN 0278-6125 J9 J MANUF SYST JI J. Manuf. Syst. PY 1998 VL 17 IS 4 BP 275 EP 286 DI 10.1016/S0278-6125(98)80075-7 PG 12 WC Engineering, Industrial; Engineering, Manufacturing; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 123ZE UT WOS:000076155000004 ER PT J AU Wang, LQ Samuels, WD Exarhos, GJ Lee, BI Cao, ZC AF Wang, LQ Samuels, WD Exarhos, GJ Lee, BI Cao, ZC TI P-31 and Si-29 NMR study of sol-gel-synthesized phosphate ceramics SO JOURNAL OF MATERIALS CHEMISTRY LA English DT Article ID GLASSES; EVOLUTION; SILICON AB P-31 and Si-29 solid-state magic angle spinning (MAS) and liquid-state nuclear magnetic resonance (NMR) techniques have been applied to the study of sol-gel-synthesized phosphate ceramic composites. This study emphasizes the chemistry and structural properties for both sols and gels prepared by directly reacting P2O5 with tetraethoxysilane (TEOS). This new method of formation of both the sols and gels is a drastic improvement in the retention of phosphorus during the formation of the phosphosilicate gels, and it provides a lower temperature route to six-coordinate silicon. Both P-31 and Si-29 liquid-state NMR spectra for sols prepared without water showed the presence of P-O-Si bonds. The P-31 NMR spectra for sols prepared with water resembled those for the PO(OH)(x)(OR)(3-x) precursors, while Si-29 NMR spectra indicated that TEOS had undergone partial hydrolysis and condensation. Hexacoordinated silicon was observed for the first time in gels prepared at low temperature(70 degrees C). P-SI gels prepared directly by using P2O5 were compared with those using other molecular precursors. C1 Pacific NW Lab, Dept Mat Sci, Richland, WA 99352 USA. Clemson Univ, Dept Mat Sci & Ceram, Clemson, SC 29634 USA. RP Wang, LQ (reprint author), Pacific NW Lab, Dept Mat Sci, Richland, WA 99352 USA. NR 19 TC 16 Z9 16 U1 2 U2 4 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 4WF, CAMBS, ENGLAND SN 0959-9428 J9 J MATER CHEM JI J. Mater. Chem. PD JAN PY 1998 VL 8 IS 1 BP 165 EP 169 DI 10.1039/a705465c PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA YT366 UT WOS:000071595100031 ER PT J AU Komarneni, S Pidugu, R Amonette, JE AF Komarneni, S Pidugu, R Amonette, JE TI Synthesis of Na-4-mica from metakaolinite and MgO: characterization and Sr2+ uptake kinetics SO JOURNAL OF MATERIALS CHEMISTRY LA English DT Article ID EXCHANGE; MICA AB Na-Li-mica. a high-charge-density sodium fluorophlogopite mica of ideal chemical composition Na4Mg6Al4Si4O20F4 . xH(2)O has been prepared from a mixture of NaF, MgO and metakaolinite (the latter serving as an inexpensive aluminosilicate source). Highly crystalline Na-4-mica can be easily and economically synthesized from the above precursors in the temperature range 850-890 degrees C. Al-27 and Si-29 MAS NMR spectroscopy revealed that the Na-4-mica synthesized from metakaolinite is more close to the ideal nearest neighbor distribution of Al and Si compared to that prepared from magnesium aluminosilicate gel. Selective Sr exchange kinetic studies showed that the uptake was slow because of the somewhat large particle size as determined by scanning electron microscopy as well as restricted interlayer spacing. C1 Penn State Univ, Intercoll Mat Res Lab, University Pk, PA 16802 USA. Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Komarneni, S (reprint author), Penn State Univ, Intercoll Mat Res Lab, University Pk, PA 16802 USA. NR 7 TC 38 Z9 38 U1 1 U2 1 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 4WF, CAMBS, ENGLAND SN 0959-9428 J9 J MATER CHEM JI J. Mater. Chem. PD JAN PY 1998 VL 8 IS 1 BP 205 EP 208 DI 10.1039/a706050e PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA YT366 UT WOS:000071595100037 ER PT J AU Raman, SV AF Raman, SV TI The effect of mixed modifiers on nuclear waste glass processing, leaching, and Raman spectra SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID SILICATE-GLASSES AB Borosilicate glasses with different waste loadings were prepared by ambient melting, quenching, and annealing. Some melt compositions partially crystallize to durable phases of zircon and forsterite. The coexisting liquid quenches to glass and endures the leach tests. The waste loading dependent leach rate trends of these glasses are reminiscent of the mixed alkali effect. Raman spectra suggest initial increase in durability with increases in the depolymerization of silicate species. Fluorine and hydroxyl ions also contribute to depolymerization. Tetraborate and metaborate rings are identified in the Raman spectra. The durability is enhanced when tetraborate bands are more intense than the metaborate bands. C1 Lockheed Martin Idaho Technol, Idaho Natl Engn Lab, Dept Nucl Engn, Idaho Falls, ID 83402 USA. RP Raman, SV (reprint author), Lockheed Martin Idaho Technol, Idaho Natl Engn Lab, Dept Nucl Engn, Idaho Falls, ID 83402 USA. NR 13 TC 11 Z9 11 U1 3 U2 4 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JAN PY 1998 VL 13 IS 1 BP 8 EP 15 DI 10.1557/JMR.1998.0002 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA ZJ203 UT WOS:000073189800003 ER PT J AU Anderson, PA Christian, JD AF Anderson, PA Christian, JD TI Alternative reagent to mercuric nitrate catalyst for dissolution of aluminum-clad nuclear fuels in nitric acid SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB A substitute additive, HBF4, has been discovered that will replace Hg(NO3)(2) catalyst for dissolving aluminium spent nuclear fuels in nitric acid for recovery of usable materials. The catalyst or substitute is necessary to penetrate a protective oxide film that continuously forms on the,Al surface in the oxidizing acid, A penetration rate of alloy Al-6061 T6 of 40 mg/cm(2)-h can be achieved in a continuous dissolution process at 100 degrees C using a dissolvent of 0.15 M HBF4 in 7 M HNO3 that achieves a steady-state composition of 1.0 M Al3+ and 3.3 M HNO3, while maintaining a corrosion rate of a type 304L stainless steel dissolver vessel of 0.015 mm/mo, The penetration rate of aluminum is correlated with the equilibrium concentration of MF in the system. The postulated mechanism involves dissolution of the alumina film by approximately 0.006 M HF in equilibrium with the HBF4 and completed aluminum fluoride species in nitric acid, which provide a large semi-buffered supply of HF. This allows. the HNO; to attack the aluminum metal. The small concentration of HF does not compete favorably with HNO3; for reaction with and consumption by Al. C1 Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Anderson, PA (reprint author), Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 14 TC 4 Z9 4 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JAN PY 1998 VL 13 IS 1 BP 68 EP 76 DI 10.1557/JMR.1998.0010 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA ZJ203 UT WOS:000073189800011 ER PT J AU Xia, CF Ward, TL Atanasova, P Schwartz, RW AF Xia, CF Ward, TL Atanasova, P Schwartz, RW TI Metal-organic chemical vapor deposition of Sr-Co-Fe-O films on porous substrates SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID PEROVSKITE-TYPE OXIDES; OXYGEN PERMEATION; CERAMIC MEMBRANES; PARTIAL OXIDATION; METHANE; SRCO0.8FE0.2O3-DELTA; SYNGAS; STEP AB Aerosol-assisted chemical vapor deposition using the beta-diketonate precursors Sr(tmhd)(2) . 2H(2)O, Fe(tmhd)(3), and Co(tmhd)(3) was investigated for depositing thin films of the mixed-conducting ceramic SrCoyFei-yO3-delta onto porous alpha-Al2O3 substrates. Single-phase SrCoyFei-yO3-delta perovskite films were obtained at a deposition temperature of 550 degrees C and pressure of 15 mm Hg, whereas deposition at atmospheric pressure produced mixed-phase films, The Co/Fe elemental ratios in the films reflected those in the precursor solution, but the films were depleted in Sr. Reduced-pressure deposition provided a more uniform film morphology than atmospheric pressure, and led to a supported film which was leak-tight to N-2 flow. C1 Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. Sandia Natl Labs, Adv Mat Lab, Albuquerque, NM 87106 USA. RP Xia, CF (reprint author), Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. NR 19 TC 26 Z9 26 U1 1 U2 4 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JAN PY 1998 VL 13 IS 1 BP 173 EP 179 DI 10.1557/JMR.1998.0023 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA ZJ203 UT WOS:000073189800024 ER PT J AU Rawn, CJ Birnie, DP Bruck, MA Enemark, JH Roth, RS AF Rawn, CJ Birnie, DP Bruck, MA Enemark, JH Roth, RS TI Structural investigation of Ba(6-3x)Ln(8+2x)Ti(18)O(54) (x = 0.27, Ln = Sm) by single crystal x-ray diffraction in space group Pnma (No. 62) SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID BOND-VALENCE PARAMETERS; DIELECTRIC-PROPERTIES; MICROWAVE CHARACTERISTICS; CERAMICS; PHASE AB Single crystals of barium samarium titanium oxide Ba6-3xSm8+2xTi18O54 (x = 0.27) have been synthesized and studied using x-ray diffraction. Superstructure reflections, which cause a doubling of the cell along the short axis, were taken into account and the refinement was conducted in the orthorhombic space group Pnma. Unit cell parameters from single crystal x-ray diffraction were a = 22.289(1), b = 7.642(1), and c = 12.133(1) Angstrom. Refinement on F resulted in R1 = 5.37% for 1410 F-o > 4 sigma with the thermal parameters of the Sm and Ba atoms refined anisotropically and the thermal parameters of the Ti and O atoms refined isotropically. The structure is made up of a network of corner sharing TiO6-2 octahedra creating rhombic (perovskite-like) and pentagonal channels. The two pentagonal channels are fully occupied by Ba atoms. The refinement suggests that one rhombic channel is fully occupied by Sm atoms (Sm3/Sm4), one rhombic channel is partially occupied by Sm atoms (100% Sm1/86.25% Sm5), and one rhombic channel is shared by Ba/Sm atoms (59.25% Ba3/40.75% Sm2), resulting in a formula of Ba10.38Sm17.08Ti36O108 with Z = 1. The above sire occupancies differ from the site occupancies previously reported in the literature for refinements conducted with the short axis approximately equal to 3.8 Angstrom. C1 Univ Ljubljana, Jozef Stefan Inst, Ljubljana 1000, Slovenia. Univ Arizona, Dept Mat Sci & Engn, Tucson, AZ 85721 USA. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. Victor Idaho Phase Equilibria Res, Victor, ID 83455 USA. RP Rawn, CJ (reprint author), Oak Ridge Natl Lab, POB 2008,Bldg 4515, Oak Ridge, TN 37831 USA. NR 33 TC 30 Z9 33 U1 0 U2 9 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JAN PY 1998 VL 13 IS 1 BP 187 EP 196 DI 10.1557/JMR.1998.0025 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA ZJ203 UT WOS:000073189800026 ER PT J AU Chaudhuri, J Low, K Jankowski, AF AF Chaudhuri, J Low, K Jankowski, AF TI Characterization of strain in annealed Cu-Ni multilayers using X-ray diffraction SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID THIN-FILMS; STABILITY; PROFILE AB The strain profile of annealed Cu-Ni multilayers was analysed using an X-ray diffraction (XRD) theory. The annealing times of the multilayers ranged from 0 to 20 h. The strain in each layer was found by fitting the theoretical peak intensities with the experimental ones by iteration and using a kinematical/dynamical theory of XRD. It was found that for increasing annealing times, there was a decrease in the strain profile due to increased interdiffusion between the Cu and Ni layers. The increase in diffusion changed the composition modulation of the multilayers progressively from a trapezoidal wave for the 0 h annealed sample to a sinusoidal wave for the 20 h annealed sample. C1 Wichita State Univ, Dept Mech Engn, Wichita, KS 67260 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Chaudhuri, J (reprint author), Wichita State Univ, Dept Mech Engn, Wichita, KS 67260 USA. RI Chaudhuri, Jharna/E-8863-2013 NR 19 TC 2 Z9 2 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JAN 1 PY 1998 VL 33 IS 1 BP 55 EP 61 DI 10.1023/A:1004381226461 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA YM456 UT WOS:000071065300008 ER PT J AU Jin, Z Gray, GT AF Jin, Z Gray, GT TI On deformation twins and twin-related lamellae in TiAl SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID PROPAGATION; ALLOYS AB The crystal orientation relationships and atomic arrangements across deformation twin planes and twin-related lamellar interfaces in [(1) over bar 10] projection directions in TiAl are examined crystallographically. Atomic arrangements across the true-twin plane and the true-twin-related lamellar interface are shown to be identical, while the atomic arrangements across the pseudo-twin plane and the pseudo-twin-related lamellar interface are quite different. Atom locations at the true-twin plane and the true-twin-related lamellar interface do not violate the atomic order in both crystals while those at the pseudo-twin plane or the pseudo-twin-related lamellar interface are shown to violate the atomic order. [(1) over bar 10] zone diffraction pattern simulations show that the true-twins and the true-twin-related lamellae cannot be distinguished using the [(1) over bar 10] zone diffraction patterns. Not every [(1) over bar 10] zone diffraction pattern can be utilized to distinguish between any two different twin relationships. The true-twin and the pseudo-twin can only be distinguished using [(1) over bar 10] zone diffraction patterns, while true-twin-related and pseudo-twin-related lamellae are distinguishable by only using [(1) over bar 10] zone diffraction patterns. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Jin, Z (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MST-5,MS G755, Los Alamos, NM 87545 USA. NR 12 TC 11 Z9 12 U1 1 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JAN 1 PY 1998 VL 33 IS 1 BP 77 EP 83 DI 10.1023/A:1004389428278 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA YM456 UT WOS:000071065300012 ER PT J AU Yonker, CR Wallen, SL Linehan, JC AF Yonker, CR Wallen, SL Linehan, JC TI Reaction chemistries in supercritical fluid solutions SO JOURNAL OF MICROCOLUMN SEPARATIONS LA English DT Article DE high-pressure NMR; supercritical fluids; metal complexes ID NUCLEAR-MAGNETIC-RESONANCE; CARBON-DIOXIDE; INFRARED-SPECTROSCOPY; LIQUID METHANOL; SOLVENT-SOLUTE; TEMPERATURE; PRESSURE; POLYMERS; ETHANE AB Supercritical fluids are versatile solvents in organic separations and extractions. The application of supercritical fluids to metal extractions is a recent extension of this technology. This application requires that three criteria be met: enhanced ligand selectivity/specificity, increased solubility of the ligand in the supercritical fluid, and ease of metal removal from the ligand after extraction. Recent efforts are described studying metal complexation and organometallic chemistry in supercritical fluids as a function of pressure and temperature. These investigations involve high-pressure NMR and FTIR studies of organometallic compounds in fluid solutions. The application of these spectroscopic techniques to the investigation of inorganic species in supercritical fluids is described in conjunction with the molecular details revealed of fluid solution structure and metal complexation dynamics. (C) 1998 John Wiley & Sons, Inc. C1 Pacific NW Lab, Environm & Hlth Sci Div, Richland, WA 99352 USA. RP Yonker, CR (reprint author), Pacific NW Lab, Environm & Hlth Sci Div, POB 999, Richland, WA 99352 USA. NR 45 TC 6 Z9 7 U1 1 U2 4 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1040-7685 J9 J MICROCOLUMN SEP JI J. Microcolumn Sep. PY 1998 VL 10 IS 1 BP 153 EP 160 DI 10.1002/(SICI)1520-667X(1998)10:1<153::AID-MCS20>3.0.CO;2-3 PG 8 WC Chemistry, Analytical SC Chemistry GA YQ743 UT WOS:000071418800020 ER PT J AU Kutter, JP Ramsey, RS Jacobson, SC Ramsey, JM AF Kutter, JP Ramsey, RS Jacobson, SC Ramsey, JM TI Determination of metal cations in microchip electrophoresis using on-chip complexation and sample stacking SO JOURNAL OF MICROCOLUMN SEPARATIONS LA English DT Article DE microfabricated devices; capillary electrophoresis; metal ion analysis; sample stacking ID PERFORMANCE CAPILLARY ELECTROPHORESIS; 8-HYDROXYQUINOLINE-5-SULFONIC ACID; ZONE ELECTROPHORESIS; POSTCOLUMN REACTOR; COLUMN CHELATION; GLASS CHIPS; SEPARATION; INJECTION; SYSTEMS; CHROMATOGRAPHY AB A method for the determination of metal cations in aqueous solution using a monolithically integrated microfabricated (microchip) device which allows sample stacking, electrophoretic separation, and postcolumn derivatization is described. The metal cations are detected by UV laser-induced fluorescence following complexation with 8-hydroxyquinoline-5-sulfonic acid. To make use of electrokinetic stacking phenomena, the sample is added to a reservoir containing a law-conductivity buffer and is then introduced into a main separation channel using a gated injection scheme. The complexing agent is added downstream from the injection cross. For two model compounds, magnesium and calcium, detection limits were 0.5 and 18 ppb, respectively. The reproducibility for multiple injections was 1.5% relative standard deviation. (C) 1998 John Wiley & Sons, Inc. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Ramsey, JM (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Kutter, Jorg/E-3256-2010 OI Kutter, Jorg/0000-0003-1065-1985 NR 33 TC 62 Z9 62 U1 1 U2 10 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1040-7685 J9 J MICROCOLUMN SEP JI J. Microcolumn Sep. PY 1998 VL 10 IS 4 BP 313 EP 319 DI 10.1002/(SICI)1520-667X(1998)10:4<313::AID-MCS1>3.0.CO;2-J PG 7 WC Chemistry, Analytical SC Chemistry GA ZT842 UT WOS:000074133300001 ER PT J AU Ding, YS Logan, J Gatley, SJ Fowler, JS Wolkow, ND AF Ding, YS Logan, J Gatley, SJ Fowler, JS Wolkow, ND TI PET studies of peripheral catechol-O-methyltransferase in non-human primates using [F-18]Ro41-0960 SO JOURNAL OF NEURAL TRANSMISSION LA English DT Article DE catechol-O-methyltransferase; fluorine-18 labeled Ro41-0960; positron emission tomography; enzyme mapping ID BRAIN TRANSFER CONSTANTS; TIME UPTAKE DATA; GRAPHICAL EVALUATION; METHYL TRANSFERASE; BABOON BRAIN; OXIDASE-B; INHIBITORS; METABOLISM; BINDING; TOLCAPONE AB We previously reported the results of PET (positron emission tomography) studies of [F-18]Ro41-0960, a potent COMT inhibitor, in baboon brain. Here we report an evaluation of the pharmacokinetics and specificity of binding of [F-18]Ro41-0960 in the peripheral organs of baboon. We observed a rapid clearance of the tracer from the heart and no significant uptake in the lung. In contrast, there was a high uptake and slow clearance in both kidney and liver, consistent with a high level of COMT in these peripheral organs. We also observed a dose-dependent inhibition of [F-18]Ro41-0960 uptake by unlabeled Ro41-0960 (ED,, was 0.5mg/kg in liver, and <0.01 mg/kg in kidney), with a half time for recovery of COMT of about 25 h at the dose of 2 mg/kg of unlabeled Ro41-0960. This indicates a reversible tight binding interaction between COMT and Ro41-0960 in both liver and kidney and suggests that [F-18]Ro41-0960 may be a useful radiotracer for future examination of the functional activity of COMT in the human body. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. RP Ding, YS (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. FU NINDS NIH HHS [NS-15380, NS-35040] NR 28 TC 5 Z9 5 U1 0 U2 1 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0300-9564 J9 J NEURAL TRANSM JI J. Neural Transm. PY 1998 VL 105 IS 10-12 BP 1199 EP 1211 DI 10.1007/s007020050123 PG 13 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA 154QT UT WOS:000077900500011 PM 9928889 ER PT J AU Gatley, SJ Lan, R Volkow, ND Pappas, N King, P Wong, CT Gifford, AN Pyatt, B Dewey, SL Makriyannis, A AF Gatley, SJ Lan, R Volkow, ND Pappas, N King, P Wong, CT Gifford, AN Pyatt, B Dewey, SL Makriyannis, A TI Imaging the brain marijuana receptor: Development of a radioligand that binds to cannabinoid CB1 receptors in vivo SO JOURNAL OF NEUROCHEMISTRY LA English DT Article DE marijuana; cannabinoid CB1 receptors; radionuclide imaging; [I-123]AM281 ID POSITRON EMISSION TOMOGRAPHY; AIRCRAFT PILOT PERFORMANCE; HUNTINGTONS-DISEASE; ANTAGONIST; BIODISTRIBUTION; LOCALIZATION; INTOXICATION; DERIVATIVES; EXPRESSION; COGNITION AB The major active ingredient of marijuana, (-)-Delta(9)-tetrahydrocannabinol, exerts its psychoactive effects via binding to cannabinoid CB1 receptors, which are widely distributed in the brain. Radionuclide imaging of CB1 receptors in living human subjects would help explore the presently unknown physiological roles of this receptor system, as well as the neurochemical consequences of marijuana dependence. Currently available cannabinoid receptor radioligands are exceedingly lipophilic and unsuitable for in vivo use. We report the development of a novel radioligand, [I-123]AM281{N-(morpholin-4-yl)-5-(4-([)(123)I]iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide}, that is structurally related to the CB1-selective antagonist SR141716A [N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1-H-pyrazole-3-carboxamide]. Baboon single photon emission computed tomography studies, mouse brain dissection studies, and ex vivo autoradiography in rat brain demonstrated rapid passage of [I-123]AM281 into the brain after intravenous injection, appropriate regional brain specificity of binding, and reduction of binding after treatment with SR141716A. AM281 has an affinity in the low nanomolar range for cerebellar binding sites labeled with [H-3]SR141716A in vitro, and binding of [I-123]AM281 is inhibited by several structurally distinct cannabinoid receptor ligands. We conclude that [I-123]AM281 has appropriate properties for in vivo studies of cannabinoid CB1 receptors and is suitable for imaging these receptors in the living human brain. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. Univ Connecticut, Dept Pharmaceut Sci, Storrs, CT USA. Univ Connecticut, Dept Mol & Cell Biol, Storrs, CT USA. RP Gatley, SJ (reprint author), Brookhaven Natl Lab, Dept Med, 490 Bell Ave, Upton, NY 11973 USA. FU NIDA NIH HHS [DA03801, DA07515, DA06278] NR 44 TC 95 Z9 98 U1 0 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0022-3042 J9 J NEUROCHEM JI J. Neurochem. PD JAN PY 1998 VL 70 IS 1 BP 417 EP 423 PG 7 WC Biochemistry & Molecular Biology; Neurosciences SC Biochemistry & Molecular Biology; Neurosciences & Neurology GA YN233 UT WOS:000071146400049 PM 9422389 ER PT J AU Remes, Z Vanecek, M Torres, P Kroll, U Mahan, AH Crandall, RS AF Remes, Z Vanecek, M Torres, P Kroll, U Mahan, AH Crandall, RS TI Optical determination of the mass density of amorphous and microcrystalline silicon layers with different hydrogen contents SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 17th International Conference on Amorphous and Microcrystalline Semiconductors - Science and Technology (ICAMS 17) CY AUG 25-29, 1997 CL BUDAPEST, HUNGARY DE mass density; silicon layers; hydrogen contents ID A-SI-H AB We have measured the density of amorphous and microcrystalline silicon films using an optical method. The mass density decreases with increasing hydrogen content, consistent with a hydrogenated di-vacancy model that fits the data for amorphous silicon. Material produced by hot wire assisted chemical vapour deposition, with low hydrogen content, has a higher density and is structurally different from glow discharge material with hydrogen content around 10 at.%. The lower density microcrystalline silicon seems to be porous. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Acad Sci Czech Republ, Inst Phys, CZ-16253 Prague 6, Czech Republic. Univ Neuchatel, Inst Microtechnol, CH-2000 Neuchatel, Switzerland. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Vanecek, M (reprint author), Acad Sci Czech Republ, Inst Phys, Cukrovarnicka 10, CZ-16253 Prague 6, Czech Republic. EM vanecek@fzu.cz RI Remes, Zdenek/G-9420-2014; Vanecek, Milan/H-1995-2014 OI Remes, Zdenek/0000-0002-3512-9256; NR 13 TC 37 Z9 37 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PY 1998 VL 227 BP 876 EP 879 DI 10.1016/S0022-3093(98)00207-5 PN B PG 4 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA ZY227 UT WOS:000074599000043 ER PT J AU Aichmayr, G Toet, D Mulato, M Santos, PV Spangenberg, A Bergmann, RB AF Aichmayr, G Toet, D Mulato, M Santos, PV Spangenberg, A Bergmann, RB TI Growth mechanisms in laser crystallization and laser interference crystallization SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 17th International Conference on Amorphous and Microcrystalline Semiconductors - Science and Technology (ICAMS 17) CY AUG 25-29, 1997 CL BUDAPEST, HUNGARY DE crystallization; transient effects; computer simulations; atomic force microscopy ID SILICON; FILMS; SOLIDIFICATION AB The processes involved in the pulsed laser crystallization of amorphous silicon thin films were studied using transient reflection measurements. A model of the melting and solidification induced by the laser exposure, based on a one-dimensional calculation of the heat flow, was used to simulate the time-dependent reflectivity, yielding agreement with the experiments. Two laser beams interfering on the sample surface lead to the growth of long grains (up to 1.5 mu m), with a well-defined orientation. We conclude that this lateral growth results from explosive crystallization combined with Liquid phase growth. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083970 Campinas, Brazil. RP Toet, D (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM toet1@llnl.gov RI Mulato, Marcelo/J-7756-2012; Inst. of Physics, Gleb Wataghin/A-9780-2017; OI Bergmann, Ralf/0000-0003-0214-2232 NR 8 TC 20 Z9 20 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PY 1998 VL 227 BP 921 EP 924 DI 10.1016/S0022-3093(98)00213-0 PN B PG 4 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA ZY227 UT WOS:000074599000052 ER PT J AU Alam, TM Brow, RK AF Alam, TM Brow, RK TI Local structure and connectivity in lithium phosphate glasses: a solid-state P-31 MAS NMR and 2D exchange investigation SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; SHORT-RANGE STRUCTURE; MAGIC-ANGLE; METAPHOSPHATE GLASSES; ROTATING SOLIDS; SPIN-1/2 NUCLEI; CRYSTALLINE; SPECTROSCOPY; SPECTRA; ALKALI AB High resolution solid-state P-31 magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy has been used to investigate the local structure and connectivity for three xLi(2)O .(1-x)P2O5 glasses. The principal components of the P-31 chemical shift anisotropy (CSA) tensors for the different phosphate tetrahedron sites (Q(n)) and the relative populations of each Q(n) species were determined from simulation of the MAS spectra. The medium range structure and connectivity between similar or different Q(n) units in these lithium phosphate glasses were probed using novel two-dimensional (2D) MAS exchange experiments. Radio-frequency dipolar recoupling (RFDR) techniques allowed the reintroduction of the through space (31)p-(31)p dipolar-dipolar interaction even in the presence of fast MAS. For these binary phosphate glasses the connectivity and medium range structure for different Q(n) species is described well by a statistical distribution, and is consistent with a model of random depolymerization. (C) 1998 Elsevier Science B.V. C1 Sandia Natl Labs, Bulk Properties Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Mat Joining Dept, Albuquerque, NM 87185 USA. RP Alam, TM (reprint author), Sandia Natl Labs, Bulk Properties Dept, POB 5800, Albuquerque, NM 87185 USA. NR 42 TC 59 Z9 60 U1 3 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JAN PY 1998 VL 223 IS 1-2 BP 1 EP 20 DI 10.1016/S0022-3093(97)00345-1 PG 20 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA YR205 UT WOS:000071471300001 ER PT J AU Hudgens, JJ Brow, RK Tallant, DR Martin, SW AF Hudgens, JJ Brow, RK Tallant, DR Martin, SW TI Raman spectroscopy study of the structure of lithium and sodium ultraphosphate glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID SHORT-RANGE STRUCTURE; PHOSPHATE-GLASSES; INFRARED-SPECTRA; TRANSITION; SCATTERING; NEUTRON; P2O5; B2O3 AB Anhydrous binary phosphate glasses containing from 0 to 50 mol% Li2O or Na2C, have been prepared and examined by Raman scattering spectroscopy. The unpolarized Raman spectrum of vitreous P2O5 has intense bands near 640 cm(-1), attributed to the symmetric stretching mode of P-O-P bridging oxygens, (POP)(sym), between Q(3) phosphate tetrahedra, and at 1390 cm(-1) due to the symmetric stretch of the P=O terminal oxygens, (P=O)(sym). With the addition of alkali oxide to P2O5, a new feature appears in the Raman spectra near 1160 cm(-1) indicating the formation of Q(2) phosphate tetrahedra with two bridging and two non-bridging oxygens. The increase in relative amplitude of this new (PO2)(sym) band with increasing modifier content is consistent with a simple depolymerization of the phosphate network. From 20 to 50 mol% alkali oxide, the position of the (P=O)(sym) Raman band decreases by similar to 130 cm(-1) whereas the freluency of the (POP)(sym) band increases by similar to 60 cm(-1). These frequency shifts are the result of pi-bond delocalization on Q(3) species that effectively lengthens the P=O terminal oxygen bond and strengthens the P-O-P Linkages with increasing alkali oxide content. The compositional dependence of the pi-bond delocalization on Q(3) tetrahedra is described by considering the interconnections between neighboring Q(3) and Q(2) tetrahedra. The onset of pi-bond delocalization on Q(3) species corresponds with the anomalous T-g minimum at 20 mol% alkali oxide in alkali ultraphosphate glasses. The increase in T-g between 20 and 50 mol% alkali oxide is attributed to the increased ionic interconnection of what becomes a chain-like phosphate network at higher alkali contents. Finally, the Raman spectra of several alkali ultraphosphate glasses show high frequency shoulders on the Raman bands attributed to the (PO2)(sym) and (PO2)(asym) vibrational modes. These shoulders represent the presence of strained structural units, possibly three- or four-membered rings. (C) 1998 Elsevier Science B.V. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Iowa State Univ Sci & Technol, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Brow, RK (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. EM rkbrow@sandia.gov NR 32 TC 202 Z9 207 U1 11 U2 52 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JAN PY 1998 VL 223 IS 1-2 BP 21 EP 31 DI 10.1016/S0022-3093(97)00347-5 PG 11 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA YR205 UT WOS:000071471300002 ER PT J AU Rong, C Wong-Moon, KC Li, H Hrma, P Cho, H AF Rong, C Wong-Moon, KC Li, H Hrma, P Cho, H TI Solid-state NMR investigation of phosphorus in aluminoborosilicate glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; ECHO DOUBLE-RESONANCE; P-31; PHOSPHATES; SPINS AB Simulants of vitrified low-level radioactive waste forms, with the approximate composition yP(2)O(5)-(0.034)SO3- (1.098)B2O3-((8.030))SiO2-AL(2)O(3)-(2.741)Na2O(where 0.071 less than or equal to y less than or equal to 0.581), have been studied by P-31 magic angle spinning (MAS) nuclear magnetic resonance (NMR) to determine the dominant modes of phosphorus incorporation in these materials, both inside and outside the glass network. Several distinct environments have been identified, with some of the nearest neighbor cations of phosphorus sites inferred by manipulating the B-11, Al-27, or Na-23 resonances together with the P-31 resonance in double resonance NMR experiments. Combined with numerical deconvolution of the P-31 MAS NMR spectra, the concentrations of the various phosphorus-containing species have been estimated from these results, and the partitioning of phosphorus in the glass is deduced. These experiments and others also reveal the existence and identities of separate ortho- and pyrophosphate phases in the glass. (C) 1998 Published by Elsevier Science B.V. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Cho, H (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999,MS K8-98, Richland, WA 99352 USA. NR 40 TC 17 Z9 17 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JAN PY 1998 VL 223 IS 1-2 BP 32 EP 42 DI 10.1016/S0022-3093(97)00436-5 PG 11 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA YR205 UT WOS:000071471300003 ER PT J AU Ramshaw, JD AF Ramshaw, JD TI Self-consistent effective binary interaction approximation for strongly coupled multifluid dynamics SO JOURNAL OF NON-EQUILIBRIUM THERMODYNAMICS LA English DT Article ID DIFFUSION AB An improved self-consistent effective binary diffusion approximation for multicomponent diffusion was recently described [1]. Here we develop an analogous self-consistent effective binary interaction (SCEBI) approximation for simplifying multifluid dynamical descriptions in which each fluid is strongly coupled to the other fluids by pairwise frictional forces. The net drag force on each fluid is the summation of the drag forces due to each of the other fluids. This summation is approximated by a single term proportional to the velocity of the fluid in question relative to an appropriately weighted average velocity. This approximation permits an explicit numerical solution for the fluid velocities even when the drag terms are evaluated at the advanced time level to avoid explicit stability restrictions on the time step. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Ramshaw, JD (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-018, Livermore, CA 94551 USA. NR 4 TC 5 Z9 5 U1 0 U2 0 PU WALTER DE GRUYTER & CO PI BERLIN PA GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY SN 0340-0204 J9 J NON-EQUIL THERMODY JI J. Non-Equilib. Thermodyn. PY 1998 VL 23 IS 2 BP 135 EP 140 DI 10.1515/jnet.1998.23.2.135 PG 6 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA 115BE UT WOS:000075643000002 ER PT J AU Kameda, J Bloomer, TE Swanson, AH Lyu, DY AF Kameda, J Bloomer, TE Swanson, AH Lyu, DY TI Neutron irradiation and intergranular fracture in vanadium 20 wt% titanium alloys undoped and doped with phosphorus and sulfur SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID SMALL-PUNCH; SOLUTE SEGREGATION; EMBRITTLEMENT; STEEL AB The mechanical properties and grain boundary composition affected by neutron irradiation (9.8 x 10(24) n/m(2): E > 0.1 MeV at 438 degrees C) in undoped, P-doped and S-doped V-20 wt% Ti alloys all containing residual C and O have been studied using a small punch testing method and scanning Auger microprobe analysis. Neutron irradiation facilitated heterogeneous formation of intergranular microcracks, not leading to specimen failure, in all undoped and some S-doped specimens. An irradiated undoped alloy indicated ductility loss to a smaller extent than expected from the easy microcracking due to a mixture of intergranular and transgranular macrocracking. The irradiation effect on the ductility varied in the S-doped alloy, while the irradiation exerted a beneficial effect on low temperature ductility in P-doped alloys. Intergranular S segregation in the undoped alloy and S desegregation in the S-doped alloy occurred during the ii-radiation. Unirradiated and irradiated P-doped alloys exhibited negligible S segregation and much smaller P segregation than the S segregation in the undoped and S-doped alloys. The grain boundary content of C affecting the ductility was remarkably reduced in the irradiated P-doped alloy and S-doped specimens with ductility loss. The ductility loss and improvement observed in the irradiated alloys are interpreted in light of the variations in segregated and precipitated impurities together with hardening behavior. (C) 1998 Elsevier Science B.V. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. EM kameda@ameslab.gov NR 26 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 EI 1873-4820 J9 J NUCL MATER JI J. Nucl. Mater. PD JAN PY 1998 VL 252 IS 1-2 BP 1 EP 12 DI 10.1016/S0022-3115(97)00328-0 PG 12 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA YX285 UT WOS:000072024900001 ER PT J AU Foster, JP Gilbert, ER Bunde, K Porter, DL AF Foster, JP Gilbert, ER Bunde, K Porter, DL TI Relationship between in-reactor stress relaxation and irradiation creep SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article AB Stress relaxation and irradiation creep data are available for 20% CW 316 SS samples fabricated from the same heat of material. The stress relaxation and irradiation creep tests were both performed in bending. The stress relaxation was calculated using an irradiation creep correlation formulated using the irradiation creep data. The calculations were in excellent agreement with the measurements and show that stress relaxation may be calculated using irradiation creep data when the proper methods are used. The methods for this calculation include the use of a transient exponential decay coefficient with a dose rate consistent with the stress relaxation application, the use of irradiation creep coefficients derived from tests with material consistent with the stress relaxation application and the use of irradiation creep data with the same stress state. (C) 1998 Elsevier Science B.V. C1 Westinghouse Elect Corp, Ctr Sci & Technol, Pittsburgh, PA 15235 USA. Pacific Natl NW Labs, Kennewick, WA 99337 USA. Argonne Natl Lab W, Idaho Falls, ID 83401 USA. RP Foster, JP (reprint author), Westinghouse Elect Corp, Ctr Sci & Technol, 1310 Beulah Rd, Pittsburgh, PA 15235 USA. NR 11 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD JAN PY 1998 VL 252 IS 1-2 BP 89 EP 97 DI 10.1016/S0022-3115(97)00294-8 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA YX285 UT WOS:000072024900011 ER PT J AU DiMelfi, RJ Alexander, DE Rehn, LE AF DiMelfi, RJ Alexander, DE Rehn, LE TI Post-yield strain hardening behavior as a clue to understanding irradiation hardening SO JOURNAL OF NUCLEAR MATERIALS LA English DT Letter ID PRESSURE-VESSEL; FERRITIC ALLOYS AB We analyze the post-yield true-stress vs. true-strain flow behavior of neutron and electron irradiated reactor pressure vessel steels, A212B and A350, and binary alloys, Fe-0.28 Cu and Fe-0.74 Ni. The flow curves suggest that neutron-irradiation hardening has the same effect as strain hardening for all the materials examined. The post-yield flow curves, obtained after electron-irradiation hardening to yield strength levels similar to those achieved by neutron irradiation, behave differently. (C) 1998 Elsevier Science B.V. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP DiMelfi, RJ (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 17 TC 12 Z9 12 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD JAN PY 1998 VL 252 IS 1-2 BP 171 EP 177 DI 10.1016/S0022-3115(97)00316-4 PG 7 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA YX285 UT WOS:000072024900022 ER PT J AU Coles, ME Hazlett, RD Spanne, P Soll, WE Muegge, EL Jones, KW AF Coles, ME Hazlett, RD Spanne, P Soll, WE Muegge, EL Jones, KW TI Pore level imaging of fluid transport using synchrotron X-ray microtomography SO JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING LA English DT Article; Proceedings Paper CT 1996 Annual Symposium of the Society-of-Core-Analysis CY 1996 CL MONTPELLIER, FRANCE SP Soc Core Anal DE microtomography; pore level; imaging; simulation ID LATTICE BOLTZMANN MODEL; COMPUTED MICROTOMOGRAPHY; POROUS-MEDIA; FLOW AB Recently developed high resolution computed microtomography (CMT) using synchrotron X-ray sources is analogous to conventional medical CT scanning and provides the ability to obtain three-dimensional images of specimens with a spatial resolution on the order of micrometers. Application of this technique to the study of core samples has previously been shown to provide excellent two-and three-dimensional high resolution descriptions of pore structure and mineral distributions of core material. Recently, computed microtomographic endpoint saturation images of a fluid filled sandstone core sample were obtained using a microtomographic apparatus and a high energy X-ray beam produced by a superconducting wiggler at the National Synchrotron Light Source at Brookhaven National Laboratory. Image of a 6 mm subsection of the one inch diameter core sample were obtained prior and subsequent to flooding to residual oil. Both oil and brine phases were observable within the imaged rock matrix. The rock matrix image data was used as input to a fluid transport simulator and the results compared with the end point saturation images and data. These high resolution images of the fluid filled pore space have not been previously available to researchers and will provide valuable insight to fluid flow, and provide data as input into and validation of high resolution porous media flow simulators, such as percolation-network and lattice Boltzmann models. (C) 1998 Elsevier Science B.V. C1 Mobil Explorat & Prod Serv Inc, Ctr Tech, Dallas, TX 75381 USA. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Mobil Explorat & Prod Serv Inc, Ctr Tech, POB 819047, Dallas, TX 75381 USA. NR 25 TC 65 Z9 70 U1 1 U2 23 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-4105 EI 1873-4715 J9 J PETROL SCI ENG JI J. Pet. Sci. Eng. PD JAN PY 1998 VL 19 IS 1-2 BP 55 EP 63 DI 10.1016/S0920-4105(97)00035-1 PG 9 WC Energy & Fuels; Engineering, Petroleum SC Energy & Fuels; Engineering GA YV394 UT WOS:000071818600006 ER PT J AU Mansour, AN Melendres, CA AF Mansour, AN Melendres, CA TI Analysis of X-ray absorption spectra of some nickel oxycompounds using theoretical standards SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID FINE-STRUCTURE SPECTRA; ELECTRONIC-STRUCTURE; EDGE STRUCTURE; K-EDGE; SPECTROSCOPY; EXAFS; OXIDES; ELECTROCHEMISTRY; HYDROXIDES; LIXNI2-XO2 AB X-ray absorption spectra have been measured for NiO, beta-Ni(OH)(2), alpha-Ni(OH)(2), LiNiO2, and KNiIO6 samples, which contain nickel with valency in the range 2-4. Information on the local structure and nature of bonding of nickel compounds has been derived using theoretical standards generated with the FEFF code. The Ni K-edge energy was found to shift to higher values by about 1.5 eV per unit change in valency of nickel. The energy of the preedge peak (generally attributed to the transition from the Is core states to the 3d unoccupied states) shifts to higher values by about 0.6 eV per unit change in valency of nickel. A many body amplitude reduction factor (S-0(2)) of 0.77 +/- 0.03 for Ni K-edge absorption can be used to scale theoretical spectra to fit the experimental ones in order to accurately determine the coordination numbers for compounds with complex structures. Our results show that chemical effects are very small and can be ignored for reliable structural analysis. Results of local structure for the first, second, and third coordination spheres for NiO are consistent with those derived from X-ray diffraction data. The results for beta-Ni(OH)(2) are much-closer in agreement with those derived from the neutron diffraction data rather than the X-ray diffraction data. The results for alpha-Ni(OH)(2) differ significantly from those based on the idealized structure model proposed by Bode et al. In fact, the structure within the hexagonal planes for alpha-Ni(OH)(2) is similar to that for beta-Ni(OH)(2). The apparent contraction in the Ni-Ni distance of the third coordination sphere for alpha-Ni(OH)(2) relative to that for beta-Ni(OH)(2), which was previously reported by others, is not real and can be attributed to structural disorder. The Ni-O bond length for divalent nickel with an octahedral coordination is in the range 2.06-2.08 Angstrom. The first coordination sphere for LiNiO2 consists of four and two oxygens at 1.91 and 2.06 Angstrom, respectively, rather than six oxygens at 2.04 Angstrom, as predicted by the X-ray diffraction data. The short distance is characteristic of Ni3+-O2- bonds and Ni2+-O- bonds, while the long distance is characteristic of Ni2+-O2- bonds. The local structure for LiNiO2 is consistent with the fact that the charge-compensating mechanism is largely due to oxygen 2p holes. The Ni-Ni second-shell distance for LiNiO2 is consistent with that based on the X-ray and neutron diffraction data. The Ni-O bond length for quadrivalent Ni in KNiIO6 is 1.88 Angstrom. The Ni-O bond length varies with nickel valency in a nonlinear manner. C1 USN, Ctr Surface Warfare, Carderock Div, W Bethesda, MD 20817 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Mansour, AN (reprint author), USN, Ctr Surface Warfare, Carderock Div, Code 684,Bldg 19-A250,9500 MacArthur Blvd, W Bethesda, MD 20817 USA. NR 61 TC 70 Z9 70 U1 6 U2 31 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JAN 1 PY 1998 VL 102 IS 1 BP 65 EP 81 DI 10.1021/jp9619853 PG 17 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YP850 UT WOS:000071322100009 ER PT J AU Curtiss, LA Miller, JR AF Curtiss, LA Miller, JR TI Distance dependence of electronic coupling through trans alkyl chains: Effects of electron correlation SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID SUPEREXCHANGE PATHWAY CALCULATION; THROUGH-BOND INTERACTIONS; LONG-RANGE INTERACTIONS; DONOR-ACCEPTOR SYSTEMS; TRANSFER KINETICS; NONCONJUGATED DIENES; CHARGE SEPARATION; THIOL MONOLAYERS; TRANSFER RATES; FREE-ENERGY AB Electronic coupling between CH2 pi donor/acceptor groups at the termini of trans alkyl chains [H2C-(CH2)(n-2)-CH2, n = 4-16] was investigated using Hartree-Fock (HF) theory, second-order Moller-Plesset perturbation theory (MP2), and density functional theory (DFT). For each method the couplings in the ions were calculated in two ways: (1) the difference in donor/acceptor orbital energies [Koopmans' theorem (KT)I and (2) the difference between the ground state and first excited state energy of the ions (Delta E). The distance dependence of the coupling in anions was found to be independent of the method used, indicating that electron correlation has little effect. In contrast, the distance dependence of the couplings in cations was very dependent on the method used. For cations, couplings from Delta DFT calculations have a weak distance dependence (beta < 0.4) similar to that found previously for KT couplings from HF (beta similar to 0.4), while couplings from KT(DFT) and Delta MP2 calculations have a stronger distance dependence (beta similar to 0.6-0.7) similar to that found previously from Delta HF calculations. When energetics are examined, it appears that the weak distance dependence for some of the methods may arise from small energy differences between the donor/acceptor levels and the energies of the filled orbitals. This was confirmed by calculations on a series of trans alkyls with different donor/acceptor groups (NH2, SiH2, PH2). The couplings for the anions have a stronger distance dependence (beta similar to 0.6-0.7) in all of the methods. Finally, it is found that the inclusion of diffuse functions in the basis set does not introduce problems for the calculation of anion couplings by density functional theory, in contrast to ab initio molecular orbital calculations where erratic results are obtained. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Curtiss, LA (reprint author), Argonne Natl Lab, Argonne, IL 60439 USA. NR 69 TC 50 Z9 50 U1 0 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JAN 1 PY 1998 VL 102 IS 1 BP 160 EP 167 DI 10.1021/jp972210c PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YP850 UT WOS:000071322100019 ER PT J AU Gole, JL Dixon, DA AF Gole, JL Dixon, DA TI Transformation, green to orange-red, of a porous silicon photoluminescent surface in solution SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID LUMINESCENCE MECHANISM; MOLECULAR-STRUCTURE; OPTICAL-PROPERTIES; ANODIC-OXIDATION; SI NANOCRYSTALS; BASIS-SETS; FILMS; ATOMS; IR; IDENTIFICATION AB The green and orange-red photoluminescent (PL) emissions characteristic of a porous silicon (PS) surface are excited with a variety of UV light sources and observed during and directly following the in situ (in solution) etching of a PS surface in a 20% HF in MeOH or 20% HF in H2O solution. Experimental observations of the time dependent behavior of this in situ PL are combined with a quantum chemical modeling of the low-lying electronic states of the silanone-based silicon oxyhydrides to suggest that the initially observed and relatively long-lived green FL, its subsequent transformation to a final orange-red emission, and its stabilization in an ethylene glycol solution are to be associated with oxyhydride electronic transitions and the chemical transformation of surface-bound oxyhydrides. C1 Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. NR 59 TC 37 Z9 37 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 1 PY 1998 VL 102 IS 1 BP 33 EP 39 DI 10.1021/jp972214h PG 7 WC Chemistry, Physical SC Chemistry GA YP851 UT WOS:000071322200007 ER PT J AU Alam, M Henderson, MA Kaviratna, PD Herman, GS Peden, CHF AF Alam, M Henderson, MA Kaviratna, PD Herman, GS Peden, CHF TI Chromyl chloride chemistry on the TiO2(110) surface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID PHOTOCATALYTIC REDUCTION; ELECTRONIC-STRUCTURE; WATER; ADSORPTION; CRO2CL2; OXIDE; CATALYSTS; MECHANISM; TITANIUM; DEFECTS AB The surface chemistry of chromyl chloride (CrO2Cl2) on TiO2(110) was examined with TPD, AES, Delta Phi, measurements, SSIMS, and XPS. CrO2Cl2 adsorbs on TiO2(110) at 130 K with a constant, coverage-independent sticking probability, which is presumably near unity based on TPD. Delta Phi data suggest the molecule is adsorbed with the oxygens bound to the surface and the chlorines pointing into vacuum. In TPD, multilayer CrO2Cl2 desorption occurs at 156 K, and monolayer desorption states occur at about 295 and 430 K. Approximately 0.09 ML. (1 ML = 5.2 x 10(14) sites/cm(2)) desorbs in each of the latter states. The remaining adsorbed CrO2Cl2 (0.48 ML) decomposes irreversibly above 500 K, eventually resulting in CrCl2 desorption above 700 K. No other decomposition products are observed in TPD. Adsorption of CrO2Cl2 at 585 K results in multilayer CrCl2 formation, while adsorption at or below 500 K results in a saturated monolayer. Between 500 and 700 K, XPS results suggest that the Cr deposited from CrO2Cl2 decomposition is reduced, possibly as the result of charge transfer from the defects in the n-doped TiO2(110). SSIMS experiments conducted on the O-18-enriched TiO2(110) indicate that O-16 brought in by CrO2Cl2 is incorporated into the surface, whereas TPD indicates that only a small fraction of this incorporated O-16 is due to isotopic exchange into the desorbing parent at 400 K. Since no oxygen-containing decomposition products were observed in TPD, the decomposition of CrO2Cl2 on TiO2(110) involves reaction at reduced surface sites (oxygen vacancies). As evidence for this, SSIMS indicates that the reaction of O-18(2) With (TiO2)-O-16(110) resulting in O-18 incorporation proceeds above 520 K presumably by the formation of oxygen vacancies from O-16(2) desorption. These results suggest that the reduction and potential immobilization of Cr(VT) species on TiO2 materials may occur thermally if the appropriate surface defect sites are present. C1 New Mexico Inst Min & Technol, Dept Mat Engn, Socorro, NM 87801 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Alam, M (reprint author), New Mexico Inst Min & Technol, Dept Mat Engn, Socorro, NM 87801 USA. OI Peden, Charles/0000-0001-6754-9928 NR 41 TC 7 Z9 7 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 1 PY 1998 VL 102 IS 1 BP 111 EP 122 DI 10.1021/jp971386b PG 12 WC Chemistry, Physical SC Chemistry GA YP851 UT WOS:000071322200017 ER PT J AU Barkigia, KM Nurco, DJ Renner, MW Melamed, D Smith, KM Fajer, J AF Barkigia, KM Nurco, DJ Renner, MW Melamed, D Smith, KM Fajer, J TI Multiconformational surfaces in porphyrins: Previews into excited-state landscapes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID PHOTOSYNTHETIC REACTION-CENTER; MOLECULAR-STRUCTURE; PHOTOPHYSICAL PROPERTIES; NONPLANAR PORPHYRINS; CRYSTAL-STRUCTURE; REDOX POTENTIALS; CATION RADICALS; PEROXIDASE; CONSEQUENCES; RESOLUTION AB The crystal structures of four different conformers of the sterically encumbered porphyrins ZnDPP, H2DPP, and NiDPP are reported (DPP = 2,3,5,7,8,10,12,13,15,17,18,20-dodecaphenylporphyrin). In combination with two previously published structures of H2DPP and NiDPP, the crystallographic results illustrate the remarkable range of different conformational surfaces possible within a single family of compounds with the same peripheral substituents. These results establish that the multiple conformational landscapes inferred from the excited-state dynamics of the molecules already exist in the ground state and thus offer previews into the conformations that may also be accessible in excited states. Electron paramagnetic resonance (EPR) results for the ZnDPP and NiDPP pi cation radicals indicate that the radicals retain sl, spin-density profiles despite the extensive peripheral substitutions and the significant nonplanarity of the parent compounds. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. RP Fajer, J (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RI Smith, Kevin/G-1453-2011 OI Smith, Kevin/0000-0002-6736-4779 NR 45 TC 50 Z9 50 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 1 PY 1998 VL 102 IS 1 BP 322 EP 326 DI 10.1021/jp973013g PG 5 WC Chemistry, Physical SC Chemistry GA YP851 UT WOS:000071322200046 ER PT J AU Alatalo, M Asoka-Kumar, P Ghosh, VJ Nielsen, B Lynn, KG Kruseman, AC Van Veen, A Korhonen, T Puska, MJ AF Alatalo, M Asoka-Kumar, P Ghosh, VJ Nielsen, B Lynn, KG Kruseman, AC Van Veen, A Korhonen, T Puska, MJ TI Effect of lattice structure on the positron annihilation with inner shell electrons SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE elements; positron annihilation spectroscopy; defects ID VACANCY DEFECTS; DX CENTER; IDENTIFICATION; SOLIDS; SEMICONDUCTORS; STATES; GAAS AB The effects of lattice structure on the high momentum part of the Doppler broadening of the positron-electron annihilation radiation was studied for a number of materials. The momentum distribution of the annihilation radiation was measured using two Ge detectors to record "in coincidence" the energies of both the upshifted and downshifted gamma rays. First-principles calculations were performed to complement the experimental data. We present results for diamond and graphite, alpha and beta Sn, amorphous and crystalline Si, well-annealed and deformed Cu, and Fe, with and without vacancy clusters. The bulk systems provide a good test case for the present approach, since the delocalized positron has no effect on the surrounding lattice. These results show that the two-detector technique, which exhibits enhanced elemental sensitivity, can also be used as a probe of the geometry of the annihilation environment, and hence can be used for identifying defect structures. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Delft Univ Technol, Interfac Reactor Inst, NL-2629 JB Delft, Netherlands. Helsinki Univ Technol, Phys Lab, FIN-02150 Espoo, Finland. RP Alatalo, M (reprint author), Brookhaven Natl Lab, Dept Phys, Bldg 510A, Upton, NY 11973 USA. RI Nielsen, Bent/B-7353-2009; Puska, Martti/E-7362-2012 OI Nielsen, Bent/0000-0001-7016-0040; Puska, Martti/0000-0002-8419-3289 NR 34 TC 21 Z9 21 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD JAN PY 1998 VL 59 IS 1 BP 55 EP 59 DI 10.1016/S0022-3697(97)00131-5 PG 5 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA YR514 UT WOS:000071502900009 ER PT J AU Hwang, JK Ramayya, AV Hamilton, JH Peker, LK Kormicki, J Babu, BRS Ginter, TN Beyer, CJ Ter-Akopian, GM Oganessian, YT Daniel, AV Ma, WC Varmette, PG Rasmussen, JO Asztalos, SJ Chu, SY Gregorich, KE Macchiavelli, AO Macleod, RW Gilat, J Cole, JD Aryaeinejad, R Butler-Moore, K Drigert, MW Stoyer, MA Bernstein, LA Lougheed, RW Moody, KJ Prussin, SG Griffin, HC Donangelo, R AF Hwang, JK Ramayya, AV Hamilton, JH Peker, LK Kormicki, J Babu, BRS Ginter, TN Beyer, CJ Ter-Akopian, GM Oganessian, YT Daniel, AV Ma, WC Varmette, PG Rasmussen, JO Asztalos, SJ Chu, SY Gregorich, KE Macchiavelli, AO Macleod, RW Gilat, J Cole, JD Aryaeinejad, R Butler-Moore, K Drigert, MW Stoyer, MA Bernstein, LA Lougheed, RW Moody, KJ Prussin, SG Griffin, HC Donangelo, R TI Close doublet structures in Mo-103, Ru-109,Ru-111, and neighbours: rotation-alignment for the half-filled h(11/2) subshell? SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Letter ID COLLECTIVE MODEL; BANDS; NUCLEI AB Several new gamma transitions are assigned to Mo-103 and Ru-109,Ru-111 in a gamma-gamma-gamma coincidence study from the spontaneous fission of Cf-252 With :72 Compton suppressed Ge detectors in Gammasphere. A close doublet structure of an odd-parity band except near its bandhead is a common feature not only of the nuclei studied here but of many others with 61 less than or equal to N less than or equal to 67. This doubler structure may be a general consequence of rotation alignment for configurations of half-filled j-shells, which are only weakly coupled to the deformed shapes. C1 Vanderbilt Univ, Dept Phys, Nashville, TN 37235 USA. Joint Inst Nucl Res, Dubna 141980, Russia. Joint Inst Heavy Ion Res, Oak Ridge, TN 37835 USA. Mississippi State Univ, Dept Phys, Mississippi State, MS 39762 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Nucl Engn, Berkeley, CA 94720 USA. Univ Michigan, Ann Arbor, MI 48104 USA. Univ Fed Rio de Janeiro, BR-68528 Rio De Janeiro, RG, Brazil. UNISOR, ORISE, Oak Ridge, TN 37831 USA. RP Vanderbilt Univ, Dept Phys, Nashville, TN 37235 USA. NR 11 TC 29 Z9 29 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0954-3899 EI 1361-6471 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD JAN PY 1998 VL 24 IS 1 BP L9 EP L16 PG 8 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA YV408 UT WOS:000071820000003 ER PT J AU Ho, CK Webb, SW AF Ho, CK Webb, SW TI Review of porous media enhanced vapor-phase diffusion mechanisms, models, and data - Does enhanced vapor-phase diffusion exist? SO JOURNAL OF POROUS MEDIA LA English DT Article ID MASS-TRANSFER; TEMPERATURE-DEPENDENCE; ISOTHERMAL CONDITIONS; SIMULTANEOUS HEAT; SOIL; FLOW; CONDUCTIVITY; BEDS AB A review of mechanisms, models, and data relevant to the postulated phenomenon of enhanced vapor-phase diffusion in porous media is presented. Information is obtained from literature spanning two different disciplines (soil science and engineering) to gain a diverse perspective on this topic. Findings indicate that while enhanced vapor diffusion tends to correct the discrepancies observed between past theory and experiments, no direct evidence exists to support the postulated processes causing enhanced vapor diffusion. Numerical modeling analyses of experiments representative of the two disciplines are presented in this paper to assess the sensitivity of different systems to enhanced vapor diffusion. Fore-scale modeling is also performed to evaluate the relative significance of enhanced vapor diffusion mechanisms when compared to Fickian diffusion. The results demonstrate the need for additional experiments so that more discerning analyses can be performed. C1 Sandia Natl Labs, Geohydrol Dept, Albuquerque, NM 87185 USA. RP Ho, CK (reprint author), Sandia Natl Labs, Geohydrol Dept, POB 5800, Albuquerque, NM 87185 USA. NR 66 TC 20 Z9 21 U1 2 U2 11 PU BEGELL HOUSE INC PI NEW YORK PA 79 MADISON AVE, SUITE 1205, NEW YORK, NY 10016-7892 USA SN 1091-028X J9 J POROUS MEDIA JI J. Porous Media PD JAN PY 1998 VL 1 IS 1 BP 71 EP 92 PG 22 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 154PB UT WOS:000077896500005 ER PT J AU Vilven, JC Domalewski, M Prossnitz, ER Ye, RD Muthukumaraswamy, N Harris, RB Freer, RJ Sklar, LA AF Vilven, JC Domalewski, M Prossnitz, ER Ye, RD Muthukumaraswamy, N Harris, RB Freer, RJ Sklar, LA TI Strategies for positioning fluorescent probes and crosslinkers on formyl peptide ligands SO JOURNAL OF RECEPTOR AND SIGNAL TRANSDUCTION RESEARCH LA English DT Article ID PROTEIN-COUPLED RECEPTORS; REAL-TIME ANALYSIS; P NK-1 RECEPTOR; NEUROKININ-1 RECEPTOR; BINDING POCKET; POLYMORPHONUCLEAR LEUKOCYTES; SUBSTANCE-P; BOVINE RHODOPSIN; HORMONE RECEPTOR; HUMAN NEUTROPHIL AB Chemoattractant receptors represent a major subset of the G-protein coupled receptor (GPCR) family. One of the best characterized, the N-formyl peptide receptor (FPR), participates in host defense responses of neutrophils. The features of the ligand which regulate its interaction with the FPR are well-known. By manipulating these features we have developed new ligands to probe structural and mechanistic aspects of the peptide-receptor interaction. Three ligand groups have been developed: 1) ligands containing a Lys residue located in positions 2 through 7 that can be conjugated to FITC (N-formyl-Met1-Lys2-Phe3-Phe4, Nformyl-Met1-Leu2-Lys3-Phe4, N-formyl-Met1-Leu2-Phe3-Lys4, N-formyl-Met1-Leu2-Phe3-Phe4-Lys5, N-formyl-nLeu1-Leu2-Phe3-nLeu4-Tyr5-Lys6 and N-formyl-Met1-Leu2-Phe3-Phe4-Gly5-Gly6-Lys7; 2) fluorescent pentapeptide ligands (N-formyl-Met-X-Phe-Phe-Lys(FITC) where X = Leu, Ala, Val or Gly); and 3) small crosslinking ligands where the photoaffinity crosslinker 4-azidosalicylic acid (ASA) was conjugated to Lys in positions 3 and 4 and p-benzoyl-phenylalanine (Bpa) was located in position 2 in N-formyl-Met1-Bpa2-Phe3-Tyr4. The peptides were characterized according to activity and affinity in human neutrophils and cell lines transfected with FPR. All of the peptides were agonists, with parallel affinity and activity. In the first group, the peptide activity decreases as Lys is placed closer to the N-formyl group and the activity is improved by 1-3 orders of magnitude by conjugation with FITC. In the second group, the dissociation rate of the peptide from the receptor increases as position 2 is replaced by aliphatic amino acids with smaller alkyl groups. In the third group, crosslinking ligands remain biologically active, display nM affinity and covalently label the FPR. C1 Univ New Mexico, Hlth Sci Ctr, Can Ctr & Pathol, Albuquerque, NM 87131 USA. Scripps Res Inst La Jolla, La Jolla, CA USA. Commonwealth Biotechnol, Richmond, VA USA. Los Alamos Natl Labs, Natl Flow Cytometry Resource, Los Alamos, NM USA. RP Vilven, JC (reprint author), Univ New Mexico, Hlth Sci Ctr, Can Ctr & Pathol, Albuquerque, NM 87131 USA. RI Prossnitz, Eric/B-4543-2008; Ye, Richard/O-5223-2016 OI Ye, Richard/0000-0002-2164-5620 FU NCRR NIH HHS [RR01315]; NIAID NIH HHS [AI36357]; PHS HHS [SBTR03 36592] NR 50 TC 14 Z9 15 U1 1 U2 1 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1079-9893 J9 J RECEPT SIGNAL TR R JI J. Recept. Signal Transduct. Res. PY 1998 VL 18 IS 2-3 BP 187 EP 221 DI 10.3109/10799899809047744 PG 35 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA ZW184 UT WOS:000074384100006 PM 9651885 ER PT J AU Horita, J Holland, HD AF Horita, J Holland, HD TI Brine inclusions in halite and the origin of the Middle Devonian Prairie evaporites of western Canada - Reply SO JOURNAL OF SEDIMENTARY RESEARCH LA English DT Editorial Material ID FLUID INCLUSIONS; POTASH EVAPORITES; SEAWATER; CHEMISTRY; BASIN C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. RP Horita, J (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008,MS6110, Oak Ridge, TN 37831 USA. NR 16 TC 3 Z9 3 U1 0 U2 0 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 1731 E 71ST STREET, TULSA, OK 74136-5108 USA SN 1073-130X J9 J SEDIMENT RES JI J. Sediment. Res. PD JAN PY 1998 VL 68 IS 1 BP 230 EP 231 PN A PG 2 WC Geology SC Geology GA YT303 UT WOS:000071587200029 ER PT J AU Balsley, SD Brady, PV Krumhansl, JL Anderson, HL AF Balsley, SD Brady, PV Krumhansl, JL Anderson, HL TI Anion scavengers for low-level radioactive waste repository backfills SO JOURNAL OF SOIL CONTAMINATION LA English DT Article DE anion scavengers; radioactive waste; repository backfills; biosphere; sorbent materials ID HYDROTALCITE-LIKE COMPOUNDS; PHYSICOCHEMICAL PROPERTIES; CONTAINING MINERALS; TECHNETIUM; ADSORPTION; IODINE; MANAGEMENT; CINNABAR; SOILS AB Minimization of I-129(-) and (99) TcO4- transport to the biosphere is critical to the success of low level radioactive waste (LLRW) storage facilities. Here we experimentally identify and classify potential sorbent materials for inclusion in LLRW backfills. For low pH conditions (pH 4-5), Cu-sulfides and possibly imogolite-rich soils provide K-d's (distribution coefficients) of roughly 18 mL g(-1) for I-, and 10(2) mL g(-1) for TcO4-. At near neutral pH, hydrotalcites, Cu-oxides, Cu-sulfides, and lignite coal possess K-d's on the order of 10(2) mL g(-1) for both I- and TcO4-. At high pH (pH > 10), such as might occur in a cementitious LLRW facility, calcium monosulfate aluminate K-d's are calculated to be roughly 10(2) mL g(-1) for both both I- and TcO4-. C1 Sandia Natl Labs, Analyt Serv, Albuquerque, NM 87185 USA. RP Balsley, SD (reprint author), Sandia Natl Labs, Analyt Serv, POB 5800, Albuquerque, NM 87185 USA. NR 31 TC 22 Z9 22 U1 0 U2 3 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 USA SN 1058-8337 J9 J SOIL CONTAM JI J. Soil Contam. PY 1998 VL 7 IS 2 BP 125 EP 141 PG 17 WC Environmental Sciences SC Environmental Sciences & Ecology GA ZE900 UT WOS:000072842900001 ER PT J AU McDonald, JP Gelston, GM AF McDonald, JP Gelston, GM TI Commentary on fate and exposure models: Description of the multimedia environmental pollutant assessment system (MEPAS (R)) version 3.2, with application to a hypothetical soil contamination scenario SO JOURNAL OF SOIL CONTAMINATION LA English DT Editorial Material C1 Pacific NW Lab, Richland, WA 99352 USA. RP McDonald, JP (reprint author), Pacific NW Lab, POB 999,Battelle Blvd,Mail Stop K6-96, Richland, WA 99352 USA. NR 16 TC 8 Z9 8 U1 0 U2 1 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 USA SN 1058-8337 J9 J SOIL CONTAM JI J. Soil Contam. PY 1998 VL 7 IS 3 BP 283 EP 300 PG 18 WC Environmental Sciences SC Environmental Sciences & Ecology GA ZR293 UT WOS:000073959600003 ER PT J AU Hetrick, DM Scott, SJ AF Hetrick, DM Scott, SJ TI Fate and exposure models: Selecting the appropriate model for a specific application. SESOIL and AT123D models SO JOURNAL OF SOIL CONTAMINATION LA English DT Article C1 Oak Ridge Natl Lab, Computat Phys & Engn Div, Oak Ridge, TN 37831 USA. Environm Graph Inc, Pewaukee, WI 53072 USA. RP Hetrick, DM (reprint author), Oak Ridge Natl Lab, Computat Phys & Engn Div, POB 2008,Bldg 6011,MS 6415, Oak Ridge, TN 37831 USA. NR 20 TC 5 Z9 5 U1 0 U2 4 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 USA SN 1058-8337 J9 J SOIL CONTAM JI J. Soil Contam. PY 1998 VL 7 IS 3 BP 301 EP 309 PG 9 WC Environmental Sciences SC Environmental Sciences & Ecology GA ZR293 UT WOS:000073959600004 ER PT J AU Brigmon, RL Bell, NC Freedman, DL Berry, CJ AF Brigmon, RL Bell, NC Freedman, DL Berry, CJ TI Natural attenuation of trichloroethylene in rhizosphere soils at the Savannah River Site SO JOURNAL OF SOIL CONTAMINATION LA English DT Article DE natural attenuation; intrinsic bioremediation; sorption; groundwater; microcosm ID STERILIZATION; BACTERIA AB Extensive trichloroethylene (TCE) groundwater contamination has resulted from discharges to a former seepage basin in the A/M Area at the Department of Energy's Savannah River Site. The direction of groundwater flow has been determined and a seep line where the contaminated groundwater is estimated to emerge as surface wafer has been identified in a region of the Southern Sector of the A/M Area. This study was undertaken to estimate the potential of four rhizosphere soils along the seep line to naturally attenuate TCE. Microcosms were setup to evaluate both biotic and abiotic attenuation of TCE. Results demonstrated that sorption to soil was the dominant mechanism during the first week of incubation, with as much as 90% of the TCE removed from the aqueous phase. Linear partitioning coefficients (K-d) ranged from 0.83 to 7.4 mL/g, while organic carbon partition coefficients (K-oc) ranged from 72 to 180 mL/gC. Diffusional losses from the microcosms appeared to be a dominant fate mechanism during the remainder of the experiment, as indicated by results from the water controls A limited amount of TCE biodegradation was observed and attempts to stimulate TCE biodegradation by either methanotrophic or methanogenic activity through amendments with methane, oxygen, and methanol were unsuccessful. The appearance of cis-1,2-dichloroethylene (c-DCE), and trans-1,2-dichloroethylene (t-DCE) confirmed the potential for anaerobic reductive dechlorination. However, these daughter products represented less than 5% of the initial TCE added. The sorption results indicate that natural attenuation may represent a viable remediation option for the TCE plume as it passes through the rhizosphere. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Environm Biotechnol Sect, Dept Environm Sci & Technol, Aiken, SC 29808 USA. Clemson Univ, Dept Environm Sci & Engn, Clemson, SC 29634 USA. RP Brigmon, RL (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Environm Biotechnol Sect, Dept Environm Sci & Technol, Bldg 704-8T, Aiken, SC 29808 USA. NR 23 TC 28 Z9 28 U1 0 U2 13 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 USA SN 1058-8337 J9 J SOIL CONTAM JI J. Soil Contam. PY 1998 VL 7 IS 4 BP 433 EP 453 PG 21 WC Environmental Sciences SC Environmental Sciences & Ecology GA 108EP UT WOS:000075253300002 ER PT J AU Stockman, HW AF Stockman, HW TI Long-term modeling of plutonium solubility at a desert disposal site, including CO2 diffusion, cellulose decay, and chelation SO JOURNAL OF SOIL CONTAMINATION LA English DT Article DE plutonium solubility; desert disposal site; CO2 diffusion; cellulose decay; and chelation ID CARBONATE COMPLEXATION; EQUILIBRIA; DEGRADATION; HYDROLYSIS; URANIUM; DIOXIDE; U(VI); SOIL AB The solubility of plutonium was estimated for waste buried at the Greater Confinement Disposal site in Nevada. The EQ3/6 thermochemical database was modified to include recent data on Pu complex formation, and the solubilities of two critical phases (probertite (CaNaB5O9. 5H(2)O), added as a backfill material; and Ca saccharate) were determined by experiment Reaction path runs were used to model effects of cellulose degradation, including complexation of actinides by organic acids and carbonate, decay of the complexing agents, and the buildup and diffusive loss of CO, through the permeable alluvium. For most waste interaction scenarios, longterm (approximate to 3.10(3) years) concentrations of Pu in pore waters are less than or equal to 10(-7) molal and are dominated by carbonate complexes, although organic complexes could dominate in the first approximate to 10(3) years. In unusual circumstances, carbonation of buried lithium could produce very high Pu solubilities; however, even in such a system, a slight lowering of the effective redox potential dramatically lowers Pu solubility. A sensitivity analysis Suggests that the "base case" calculations are conservative, tending to overestimate long-term solubility, with the system redox and the identity of the organic acids the major sources of uncertainty. C1 Sandia Natl Labs, Dept 6118, Albuquerque, NM 87185 USA. RP Stockman, HW (reprint author), Sandia Natl Labs, Dept 6118, POB 5800, Albuquerque, NM 87185 USA. NR 64 TC 4 Z9 4 U1 0 U2 0 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 USA SN 1058-8337 J9 J SOIL CONTAM JI J. Soil Contam. PY 1998 VL 7 IS 5 BP 615 EP 647 PG 33 WC Environmental Sciences SC Environmental Sciences & Ecology GA 124ZU UT WOS:000076213400006 ER PT J AU Napolitano, GE Richmond, JE Stewart, AJ AF Napolitano, GE Richmond, JE Stewart, AJ TI Characterization of petroleum-contaminated soils by thin-layer chromatography with flame ionization detection SO JOURNAL OF SOIL CONTAMINATION LA English DT Article DE TPH-contaminated soils; TLC/FID; soil synoptic surveys ID HYDROCARBONS; LIPIDS AB Petroleum hydrocarbons from 20 soils from refineries or other industrial sites were extracted with a mixture Of chloroform and methanol (I:1, v/v), and the extracts were analyzed by thin layer chromatography with flame ionization detection (TLC/FID). The TLC/FID procedure has been used widely in biological and medical research but generally has been underutilized in environmental chemistry The analysis method involved spotting a small volume of sample extract (typically I to 3 mu l) on ten silica-coated quartz rods, and chromatographically separating constituents in the spots using solvent systems of increasing polarities (hexane, toluene, smd dichloromethane + methanol). We achieved complete separation of saturated hydrocarbons, aromatic hydrocarbons, resins, and asphaltenes from the hydrocarbon-contaminated soils with this method. Analysis of the separated constituents by TLC/FID also allowed quantification of aromatic and aliphatic hydrocarbons without interference from soil biogenic lipids. A simplified version of the method permitted excellent separation of aliphatics + aromatics (forming a single peak) from resins and asphaltenes. The procedure Is rapid (complete analysis of ten samples in about 1 h after extraction). Thus, the method seems well suited for synoptic surveys or screening and characterizing numerous samples prior to using more detailed and costly analyses. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Napolitano, GE (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. OI stewart, arthur/0000-0003-1968-5997 NR 18 TC 7 Z9 7 U1 0 U2 3 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 USA SN 1058-8337 J9 J SOIL CONTAM JI J. Soil Contam. PY 1998 VL 7 IS 6 BP 709 EP 724 PG 16 WC Environmental Sciences SC Environmental Sciences & Ecology GA 144AQ UT WOS:000077290700006 ER PT J AU Thomas, IM AF Thomas, IM TI Aerial oxidation of tetraethyl silicate and effect on ammonia catalyzed hydrolysis SO JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY LA English DT Article DE tetraethyl silicate; antireflective coatings; colloidal silica; silica particle size AB Colloidal suspensions of SiO2 in ethanol prepared by the ammonia catalyzed hydrolysis of tetraethyl silicate (TEOS) in ethanol have been routinely used for over 10 years to prepare antireflective (AR) coatings on the fused silica transmissive optical components of high power fusion lasers. Very high purity coatings are required to avoid laser damage and these are obtained when the TEOS is fractionally distilled under N-2 prior to use. Recently we found that products from aerial oxidation of distilled TEOS, had a significant effect on the particle size of our coating suspensions to the detriment of the optical performance. We require particle sizes less than 20 nm to avoid light loss due to scatter and contaminated TEOS gave suspensions with much higher particle sizes. Oxidation products were identified by GC mass spectroscopy and included acetaldehyde, acetic acid, silicon acetates and reaction products of these compounds with ethanol. Acetic acid and silicon acetates were found to be the major cause of large particle formation. These could be removed by careful redistillation preferably in the presence of a small quantity of magnesium ethoxide. Storage in sealed containers under N-2 avoided further problems. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Thomas, IM (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 East Ave,Mail Stop L-483, Livermore, CA 94550 USA. NR 4 TC 0 Z9 0 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0928-0707 J9 J SOL-GEL SCI TECHN JI J. Sol-Gel Sci. Technol. PY 1998 VL 13 IS 1-3 BP 713 EP 716 DI 10.1023/A:1008649107175 PG 4 WC Materials Science, Ceramics SC Materials Science GA 164MM UT WOS:000078468200124 ER PT J AU Kim, KK Yokota, H Santoso, S Lerner, D Kim, R Kim, SH AF Kim, KK Yokota, H Santoso, S Lerner, D Kim, R Kim, SH TI Purification, crystallization, and preliminary x-ray crystallographic data analysis of small heat shock protein homolog from Methanococcus jannaschii, a hyperthermophile SO JOURNAL OF STRUCTURAL BIOLOGY LA English DT Article DE hyperthermophile; Methanococcus jannaschii; small heat shock protein; X-ray crystallography ID ALPHA-CRYSTALLIN; CHAPERONE; FAMILY AB A gene coding for a small heat shock protein homolog from the hyperthermophilic methanogenic Archaeon Methanococcus jannaschii was cloned. This gene was overexpressed in Escherichia coli harboring rare codon tRNAs and its protein purified and crystallized. Crystals displayed the space group R3 with unit cell dimensions a = b = 171.46 Angstrom and c = 102.13 Angstrom in a hexagonal axis setting. These crystals grew in one week and diffracted to 3.2 Angstrom resolution. The presence of eight molecules in the asymmetric unit gives a V-m value of 2.2 Angstrom(3)/Da and a solvent content of 44% by volume. The 24-molecule complex is generated from a subunit by a combination of crystallographic threefold symmetry and three types of noncrystallographic symmetries (a two-, a three-, and a fourfold). (C) 1998 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Biol Struct, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Kim, SH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Biol Struct, Berkeley, CA 94720 USA. NR 22 TC 44 Z9 45 U1 0 U2 4 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1047-8477 J9 J STRUCT BIOL JI J. Struct. Biol. PD JAN PY 1998 VL 121 IS 1 BP 76 EP 80 DI 10.1006/jsbi.1998.3969 PG 5 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA ZJ238 UT WOS:000073193800010 PM 9573624 ER PT J AU Tsui, OKC Mochrie, SGJ Berman, LE AF Tsui, OKC Mochrie, SGJ Berman, LE TI Statistical analysis of X-ray speckle at the NSLS SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE X-ray speckle; coherent X-rays AB A statistical analysis of the static speckle produced by illuminating a disordered aerogel sample by a nominally coherent X-ray beam at wiggler beamline X25 at the National Synckrotron Light Source is reported. The results of the analysis show that the coherence delivered to the X25 hutch is within 35% of what is expected. The rate of coherent photons is approximately two times smaller than expected on the basis of the X25 wiggler source brilliance. C1 MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Tsui, OKC (reprint author), MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA. OI Tsui, Ophelia K. C./0000-0001-5987-2733 NR 14 TC 13 Z9 13 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD JAN 1 PY 1998 VL 5 BP 30 EP 36 DI 10.1107/S090904959701039X PN 1 PG 7 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA ZA196 UT WOS:000072338600006 PM 16687798 ER PT J AU Abernathy, DL Grubel, G Brauer, S McNulty, I Stephenson, GA Mochrie, SGJ Sandy, AR Mulders, N Sutton, M AF Abernathy, DL Grubel, G Brauer, S McNulty, I Stephenson, GA Mochrie, SGJ Sandy, AR Mulders, N Sutton, M TI Small-angle X-ray scattering using coherent undulator radiation at the ESRF SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE coherent X-rays; speckle; intensity fluctuation spectroscopy ID GRAZING-INCIDENCE; SPECKLE; SPECTROSCOPY; DIFFRACTION; RESOLUTION AB A simple approach for producing a high-coherent-flux X-ray beam for small-angle-scattering studies used at the Troika beamline of the European Synchrotron Radiation Facility is reported. For such small-angle studies it is permissible to reduce the longitudinal coherence length of the beam, thus increasing the energy bandpass and intensity of the beam, because there is only a small optical pathlength difference. By using mirrors and filters to cut unwanted energies from the undulator harmonic structure, a high-flux beam of >10(9) photons s(-1) through a 5 mu m-diameter pinhole at 8.2 keV with a bandpass of 1.3% can be produced. The coherent properties of this beam have been measured by analyzing a static speckle pattern from an aerogel sample imaged by a directly illuminated CCD camera. The speckle size and contrast are compared with the expected values based on a statistical analysis of the intensity distribution of speckle patterns obtained using partially coherent conditions. The expected widths of the spatial autocorrelation are found, but there is an apparent incoherent fraction of the beam which reduces the measured contrast. The method presented is to be used as a tool to optimize conditions for diffraction experiments using coherent X-rays. C1 European Synchrotron Radiat Facil, F-38043 Grenoble, France. MIT, Cambridge, MA 02139 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Delaware, Newark, DE 19716 USA. McGill Univ, Montreal, PQ H3A 2T8, Canada. RP Abernathy, DL (reprint author), European Synchrotron Radiat Facil, BP 220, F-38043 Grenoble, France. EM aber@esrf.fr RI Abernathy, Douglas/A-3038-2012 OI Abernathy, Douglas/0000-0002-3533-003X NR 28 TC 92 Z9 92 U1 2 U2 18 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD JAN 1 PY 1998 VL 5 BP 37 EP 47 DI 10.1107/S0909049597015835 PN 1 PG 11 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA ZA196 UT WOS:000072338600007 PM 16687799 ER PT J AU Macedonia, CR Littlefield, RJ Coleman, J Satava, RM Cramer, T Mogel, C Eglinton, G AF Macedonia, CR Littlefield, RJ Coleman, J Satava, RM Cramer, T Mogel, C Eglinton, G TI Three-dimensional ultrasonographic telepresence SO JOURNAL OF TELEMEDICINE AND TELECARE LA English DT Article ID FETAL TELEMEDICINE; ULTRASOUND; VIDEO AB We have developed a three-dimensional ultrasound telepresence system for remote consultation. Three-dimensional ultrasound data-sets can be acquired by relatively unskilled operators. The data are stored in the remote unit and then transmitted to a consultant equipped with a similar unit. A telepresence pointing device enables the consultant to re-slice that data-set in any plane. During the study period, 72 volumetric scans of male and female volunteers aged 18-45 years were performed in Bosnia. Field users of limited ultrasound experience (most with less than 30 min of training) were able to acquire volumetric scans, send volume data and interact with remote consultants over standard communications lines at distances of up to 20,000 km. Communications links from 9.6 to 1500 kbit/s were used. Technical limitations included lack of motion data, lack of colour data, scan artefacts and increased scan-to-diagnosis time. However, our preliminary experience indicates that this technique may eventually prove to be a useful adjunct to telesonography. Further studies of the technique are needed to determine its value in the broader clinical setting. C1 Georgetown Univ, Med Ctr, Dept Obstet & Gynecol, Washington, DC 20007 USA. Pacific NW Natl Lab, Hanford, WA USA. Yale Univ, Sch Med, Dept Surg, New Haven, CT 06510 USA. Telemed Res Lab, Ft Detrick, MD USA. RP Macedonia, CR (reprint author), Georgetown Univ, Med Ctr, Dept Obstet & Gynecol, 3800 Reservoir Rd, Washington, DC 20007 USA. NR 14 TC 15 Z9 15 U1 0 U2 0 PU ROYAL SOC MEDICINE PRESS LTD PI LONDON PA 1 WIMPOLE STREET, LONDON W1M 8AE, ENGLAND SN 1357-633X J9 J TELEMED TELECARE JI J. Telemed. Telecare PY 1998 VL 4 IS 4 BP 224 EP 230 DI 10.1258/1357633981932280 PG 7 WC Health Care Sciences & Services SC Health Care Sciences & Services GA 148EZ UT WOS:000077492900007 PM 10505359 ER PT J AU Holzrichter, JF Burnett, GC Ng, LC Lea, WA AF Holzrichter, JF Burnett, GC Ng, LC Lea, WA TI Speech articulator measurements casing low power EM-wave sensors SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Letter AB Very low power electromagnetic (EM) wave sensors are being used to measure speech articulator motions as speech is produced. Glottal tissue oscillations, jaw, tongue, soft palate, and other organs have been measured. Previously, microwave imaging (e.g., using radar sensors) appears not to have been considered for such monitoring. Glottal tissue movements detected by radar sensors correlate well with those obtained by established laboratory techniques, and have been used to estimate a voiced excitation function for speech processing applications. The noninvasive access, coupled with the small size, low power, and high resolution of these new sensors, permit promising research and development applications in speech production, communication disorders, speech recognition and related topics. (C) 1998 Acoustical Society of America. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Speech Sci Inst, Apple Valley, MN 55124 USA. RP Holzrichter, JF (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. EM holzrichter1@llnl.gov NR 17 TC 30 Z9 34 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JAN PY 1998 VL 103 IS 1 BP 622 EP 625 DI 10.1121/1.421133 PG 4 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA YR454 UT WOS:000071496900062 PM 9440346 ER PT J AU Park, YS McNallan, MJ Butt, DP AF Park, YS McNallan, MJ Butt, DP TI Endothermic reactions between mullite and silicon carbide in an argon plasma environment SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MATRIX COMPOSITES; SIC-WHISKER; OXIDATION; FIBERS; OXIDE AB Reactions between SiC and mullite in an Ar plasma were investigated using a model composite in which a freestanding CVD SiC coupon was imbedded in mullite cement. After treatment in a radio frequency (RF) plasma, the Si content of the mullite in contact with SiC was found to be less than that in the starting material, and deposits were found on the walls of the plasma chamber due to the reaction of mullite with SiC as follows: Al6Si2O13(s) + SiC(s) = 3Al(2)O(3)(s) + 3SiO(g) + CO(g). This reaction, which is endothermic (1405 kJ/mol at 1500 K), absorbs thermal energy and consequently prevents the rapid sintering which is observed for single-phase mullite in similar environments, As a consequence, it is suggested that RF plasma sintering probably cannot be used to densify SiC-reinforced mullite-matrix composites because of the resulting energy consumption and damage to the SiC phase. C1 Univ Illinois, Dept Mat Sci Engn, Chicago, IL 60607 USA. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Park, YS (reprint author), Univ Illinois, Dept Mat Sci Engn, Chicago, IL 60607 USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 20 TC 2 Z9 2 U1 0 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JAN PY 1998 VL 81 IS 1 BP 233 EP 236 PG 4 WC Materials Science, Ceramics SC Materials Science GA YU345 UT WOS:000071707800033 ER PT J AU Li, T Scotch, AM Chan, HM Harmer, MP Park, SE Shrout, TR Michael, JR AF Li, T Scotch, AM Chan, HM Harmer, MP Park, SE Shrout, TR Michael, JR TI Single crystals of Pb(Mg1/3Nb2/3)O-3-35 mol% PbTiO3 from polycrystalline precursors SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID GRAIN-GROWTH; BOUNDARY AB A potentially more cost-efficient method of growing single-crystal relaxer-based ferroelectric materials has been investigated, Seed single crystals of Pb(Mg1/3Nb2/3)O-3 (PMN)-35 mol% PbTiO3 (PT) were embedded within polycrystalline powders and annealed at temperatures from 900 degrees to 1200 degrees C. The boundary of the single crystal migrated through the polycrystal matrix under the influence of grain boundary curvature; growth distances of several millimeters were observed, verifying the feasibility of the approach, The grown single crystals exhibited macroscopic cubic growth morphologies with (100) faces. Strain levels as high as 0.68% under an electric field of 30 kV/cm were observed in initial measurements. C1 Lehigh Univ, Mat Res Ctr, Bethlehem, PA 18015 USA. Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Li, T (reprint author), Lehigh Univ, Mat Res Ctr, Bethlehem, PA 18015 USA. NR 15 TC 71 Z9 76 U1 2 U2 14 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JAN PY 1998 VL 81 IS 1 BP 244 EP 248 PG 5 WC Materials Science, Ceramics SC Materials Science GA YU345 UT WOS:000071707800036 ER PT J AU Bamberger, CE Specht, ED AF Bamberger, CE Specht, ED TI Orthophosphates and diphosphates containing zinc and copper and zinc and cobalt SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB Solid solutions of diphosphates of zinc and copper and of zinc and cobalt were synthesized from mixtures of pure diphosphates at temperatures up to 1000 degrees C. Their X-ray diffractometry patterns varied continuously from one end member to the other, Solid solutions of orthophosphates of composition Zn3-xCox(PO4)(2), with x = 0.41-1.6, were formed at temperatures up to 950 degrees C; all exhibited the structure of gamma-Zn-3(PO4)(2). Solid solutions of orthophosphates of composition Zn3-xCux(PO4)(2) exhibited more-complex behavior. At 1000 degrees C and copper contents of 20-80 mol%, a phase that is related to Cu-3(PO4)(2), termed here the "epsilon-phase," predominated. At 850 degrees-950 degrees C and in the region from 20 mol% to similar to 33 mol% of copper, the solid solutions (the "eta-phase") adopted the structure of graftonite. At 800 degrees-900 degrees C and 10-15 mol% of copper, the solid solutions exhibited a new structure (the "delta-phase"), which we found to be related to the mineral sarcopside. At temperatures greater than or equal to 950 degrees C, the solutions that contained 5-15 mol% of copper (the "beta-phase") had the structure of beta-Zn-3(PO4)(2), whereas at 800 degrees-850 degrees C, solutions with 5 mol% of copper (the "gamma-phase") exhibited the structure of gamma-Zn-3(PO4)(2). Attempts to synthesize Cu+ZnPO4 and Cu+Cu2+Zn3(PO4)(3) were unsuccessful. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Bamberger, CE (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Specht, Eliot/A-5654-2009 OI Specht, Eliot/0000-0002-3191-2163 NR 9 TC 3 Z9 3 U1 0 U2 7 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JAN PY 1998 VL 81 IS 1 BP 252 EP 256 PG 5 WC Materials Science, Ceramics SC Materials Science GA YU345 UT WOS:000071707800038 ER PT J AU Forslund, DW George, JE Gavrilov, EM Zink, S Zimnik, P AF Forslund, DW George, JE Gavrilov, EM Zink, S Zimnik, P TI TeleMed: Evaluation of use in rural telemedicine SO JOURNAL OF THE AMERICAN MEDICAL INFORMATICS ASSOCIATION LA English DT Meeting Abstract C1 Los Alamos Natl Lab, Los Alamos, NM USA. USA, Med Res & Mat Command, Ft Detrick, MD USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU HANLEY & BELFUS INC PI PHILADELPHIA PA 210 S 13TH ST, PHILADELPHIA, PA 19107 USA SN 1067-5027 J9 J AM MED INFORM ASSN JI J. Am. Med. Inf. Assoc. PY 1998 SU S BP 1118 EP 1118 PG 1 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Information Science & Library Science; Medical Informatics SC Computer Science; Information Science & Library Science; Medical Informatics GA V3156 UT WOS:000171768600340 ER PT J AU Groenewold, GS Appelhans, AD Ingram, JC AF Groenewold, GS Appelhans, AD Ingram, JC TI Characterization of bis(alkylamine)mercury cations from mercury nitrate surfaces by using an ion trap secondary ion mass spectrometer SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID ATOMIC-ABSORPTION SPECTROMETRY; GAS-PHASE; STATIC SIMS; SPECIATION; CHEMISTRY; CHROMATOGRAPHY; DERIVATIVES; IONIZATION; SOILS AB Mercury-cyclohexylamine (R-NH2, where R = c-C6H11) ions having the composition Hg(R-NH)(2)H+ can be formed by exposing the surface of Hg(NO3)(n=1,2) salts to gaseous primary amines and then sputtering the surface with a primary ion beam (ReO4-). The resultant ions can be stabilized and detected using an ion trap secondary ion mass spectrometer (IT-SIMS) instrument, which provides collisional stabilization that facilitates their observation. Isolation of the Hg(R-NH)(2)H+ ions followed by collisional activation produces daughter ions corresponding to (C6H10NH2)(+) and Hg(R-NH)(+). These assignments were supported by deuterium labeling experiments, which resulted in the formation of Hg(R-NH)(R-NH-d(11))H+ and Hg(R-NH)(2)H+. The existence of the Hg(R-NH)(2) compounds on the surface was verified using Raman spectroscopy, which showed a strong absorption at 590 cm(-1) that corresponded to Hg-N stretching. Analogous ions could be formed with n-hexylamine, but no Hg-bearing ions were formed when starting with a secondary or a tertiary amine. This indicates that only primary amines will react with Hg-nitrate surfaces in this manner. Hg-amine ions could not be formed starting with other Hg salts: chloride, iodide, thiocyanate, sulfate, and oxide. These results suggest that surface derivatization using amines, coupled with an IT-SIMS instrument, may offer an approach for determining inorganic metal speciation on surfaces. (C) 1998 American Society for Mass Spectrometry. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Groenewold, GS (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 43 TC 22 Z9 22 U1 1 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD JAN PY 1998 VL 9 IS 1 BP 35 EP 41 DI 10.1016/S1044-0305(97)00231-6 PG 7 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA YN227 UT WOS:000071145800006 ER PT J AU Baker, RD Schubert, G Jones, PW AF Baker, RD Schubert, G Jones, PW TI Cloud-level penetrative compressible convection in the Venus atmosphere SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GRAVITY-WAVES; CELLULAR CONVECTION; RADIO OCCULTATION; GENERATION; PATTERNS; DYNAMICS; GALILEO AB A two-dimensional, nonlinear, fully compressible model of a perfect gas is used to simulate cloud-level penetrative convection in the Venus atmosphere from 40 to 60 km altitude. Three cases with different amounts of solar heating are considered: 60%, 80%, and 100% subsolar heating conditions corresponding to maximum internally heated Rayleigh numbers of 4.0 x 10(6), 5.4 x 10(6), and 6.8 x 10(6), respectively. Cloud-level convection is characterized by cold, narrow downwellings that deeply penetrate (similar to 5 km) the underlying stable layer. The horizontal spacing of the downwellings is 15-30 km, an order of magnitude smaller than observed cloud-top cells in ultraviolet images. The penetrating head of the downflow is both mechanically forced upward and compressionally heated by the underlying stable layer. The local compressional heating rate induced by penetration is four orders of magnitude larger than the solar heating rate. Although slightly larger in magnitude, the calculated vertical velocities at 54-km altitude are consistent with Vega balloon measurements. The computations show that the Vega balloons drifted in a relatively quiescent part of the convection layer. Vertical velocities are three to five times larger in the lower pari of the convection layer than in the upper part of the layer because of the dominance of convection by intense downwellings that acquire their highest speeds as they penetrate the underlying stable region. Mixing length theory underestimates the vertical velocity of convection by a factor of 3 or more because kinetic energy in the convection layer is balanced not only by buoyancy work as assumed by mixing length theory, but also by pressure work and viscous work. A transfer of energy from low-frequency convective modes to higher-frequency "interfacial" penetrative modes occurs in the penetrative region. Internal gravity waves are also generated in the stable layers with horizontal wavelengths of 5-30 km and intrinsic horizontal phase speeds comparable to convective velocities. C1 Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM USA. RP Baker, RD (reprint author), Univ Calif Los Angeles, Dept Earth & Space Sci, Box 951567,3806 Geol Bldg, Los Angeles, CA 90095 USA. NR 54 TC 24 Z9 24 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD JAN 1 PY 1998 VL 55 IS 1 BP 3 EP 18 DI 10.1175/1520-0469(1998)055<0003:CLPCCI>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YQ943 UT WOS:000071440400001 ER PT J AU Perry, ML Newman, J Cairns, EJ AF Perry, ML Newman, J Cairns, EJ TI Mass transport in gas-diffusion electrodes: A diagnostic tool for fuel-cell cathodes SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article; Proceedings Paper CT Meeting of the Electrochemical-Society CY OCT 06-11, 1996 CL SAN ANTONIO, TEXAS SP Electrochem Soc ID OXYGEN REDUCTION; PHOSPHORIC-ACID; VOLTAGE LOSSES; KINETICS; MODEL; TEMPERATURE; CARBON; WATER AB Two mathematical models of gas-diffusion electrodes, one for liquid electrolytes and one for ion-exchange polymer electrolytes, are presented to investigate the effects of mass-transport limitations on the polarization characteristics of a reaction obeying Tafel kinetics. The focus is on low-temperature fuel-cell cathodes, and in particular, contrasting two Limiting cases that may be encountered at high current densities: control by kinetics and dissolved oxygen mass transport vs. control by kinetics and ionic mass transport. It is shown that two distinct double Tafel slopes may arise from these two limiting cases. The former is first order and the latter is half-order with respect to oxygen concentration. How the modeling results may be applied to diagnose the performance of fuel-cell cathodes is also presented. Since the ionic-mass-transport-limited case has generally been neglected in previous gas-diffusion electrode models, specific examples of fuel, cell cathode data from the literature which display the behavior predicted by the models in this case are given and briefly discussed. C1 Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Energy & Environm, Berkeley, CA 94720 USA. RP Perry, ML (reprint author), DuPont, Wilmington, NC 28402 USA. RI Newman, John/B-8650-2008; Cairns, Elton/E-8873-2012 OI Newman, John/0000-0002-9267-4525; Cairns, Elton/0000-0002-1179-7591 NR 38 TC 229 Z9 232 U1 3 U2 40 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JAN PY 1998 VL 145 IS 1 BP 5 EP 15 DI 10.1149/1.1838202 PG 11 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA YQ399 UT WOS:000071382900007 ER PT J AU Mao, D Ibrahim, MA Frank, AJ AF Mao, D Ibrahim, MA Frank, AJ TI A plasticized polymer-electrolyte-based photoelectrochemical solar cell SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID PHOTO-VOLTAIC CELL; SCHOTTKY-BARRIER; JUNCTIONS; SULFIDE AB A photoelectrochemical solar cell based on an n-GaAs/polymer-redox-electrolyte junction is reported. Di(ethylene glycol)ethyl ether acrylate containing ferrocene as a redox species and benzoin methyl ether as a photoinitiator is polymerized in situ. Propylene carbonate is used as a plasticizer to improve the conductivity of the polymer redox electrolyte. For thin (1 mu m) polymer electrolytes, the series resistance of the cell is negligible. However, the short-circuit photocurrent density of the cell at light intensities above 10 mW/cm(2) is limited by mass transport of redox species within the polymer matrix. At a light intensity of 70 mW/cm(2), a moderate light-to-electrical energy conversion efficiency (3.1%) is obtained. The interfacial charge-transfer properties of the cell in the dark and under illumination are studied. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Mao, D (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 21 TC 8 Z9 10 U1 2 U2 8 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JAN PY 1998 VL 145 IS 1 BP 121 EP 124 DI 10.1149/1.1838223 PG 4 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA YQ399 UT WOS:000071382900028 ER PT J AU Zhuang, GR Ross, PN Kong, FP McLarnon, F AF Zhuang, GR Ross, PN Kong, FP McLarnon, F TI The reaction of clean Li surfaces with small molecules in ultrahigh vacuum SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID LITHIUM; TETRAHYDROFURAN; WATER; H2O; ELECTROLYTES; CU(001); ADATOMS; FILMS; XPS AB Reactions at the Li/H2O interface were studied at 160 to 290 K in ultrahigh vacuum by a combination of spectroscopic ellipsometry and Anger electron spectroscopy. Ice multilayers, ca. 100 ML thick, were deposited on clean Li at 160 K. The evaporation rate of water at 160 K is sufficiently slow that the ice layer remains on the surface for about 1 h. After 10 mill at 160 k, a pure LiOH layer ca. 70 Angstrom thick is produced, and after 1 h there is evidence of a slow conversion of LiOH to Li2O in the layer, probably at the Li/LiOH interface. Raising the temperature to 240 K results in desorption of the adsorbed water and conversion of all the LiOH to a porous (60% void) layer composed mostly of Li2O (35%) with some metallic Li mixed in. Raising the temperature further to 290 K results in densification of the layer by both collapse of the voids and by diffusion of Li into the interstices of the Li2O, increasing the Li content to 27% and shrinking the film thickness to 26 Angstrom. Based on these results, a model for the behavior of small amounts of water in Li battery electrolyte is presented. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Zhuang, GR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 28 TC 7 Z9 7 U1 4 U2 11 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JAN PY 1998 VL 145 IS 1 BP 159 EP 164 DI 10.1149/1.1838229 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA YQ399 UT WOS:000071382900034 ER PT J AU Xia, CF Ward, TL Xu, CY Atanasova, P Schwartz, RW AF Xia, CF Ward, TL Xu, CY Atanasova, P Schwartz, RW TI Fabrication of Ag/Y2O3-stabilized ZrO2 composite films by metallorganic chemical vapor deposition SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Letter ID YTTRIA-STABILIZED ZIRCONIA; MEMBRANE REACTORS; DEFECT STRUCTURE; OXYGEN-ION; CONDUCTIVITY; TERBIA; TRANSPORT AB Composite films of Ag and Y2O3-stabilized ZrO2 have been prepared by simultaneous metallorganic chemical vapor deposition (MOCVD) of the metal and ceramic. Aerosol-assisted precursor delivery of a toluene solution of the precursors Zr(tfac)(4), Y(hfac)(3), and (hfac)Ag(C4H8OS)(2) was used to deposit films with Ag volume fractions ranging from 0.007 to 0.60 (hfac = hexafluoroacetylacetonate, tfac = trifluoroacetylacetonate). Film morphology and room-temperature resistivity varied with Ag content. Resistivities for Ag volume fractions above 0.30 were consistent with typical granular composite films; however, at Ag volume fractions below 0.10, much lower resistivities were found than are typically reported. The percolation behavior of the films is analyzed and possible explanations for the resistivity results are discussed. C1 Univ New Mexico, Ctr Microengineered Mat, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Sandia Natl Labs, Adv Mat Lab, Albuquerque, NM 87106 USA. RP Xia, CF (reprint author), Univ New Mexico, Ctr Microengineered Mat, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. NR 24 TC 1 Z9 2 U1 1 U2 3 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JAN PY 1998 VL 145 IS 1 BP L4 EP L8 DI 10.1149/1.1838197 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA YQ399 UT WOS:000071382900002 ER PT J AU Becher, PF Plucknett, KP AF Becher, PF Plucknett, KP TI Properties of Ni3Al-bonded titanium carbide ceramics SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article ID FRACTURE; HARDMETALS; CERMETS AB Cemented carbides are widely used in applications where resistance to abrasion and wear are important, particularly in combination with high strength and stiffness. In the present case, ductile nickel aluminide (Ni3Al), was used as a binder phase to fabricate dense TiC cermets by either sintering of mixed powders or a melt-infiltration sintering process. The choice of an aluminide binder was based on the exceptional high temperature strength and chemical stability exhibited by these alloys. The resultant TiC-Ni3Al composites exhibit improved oxidation resistance, Young's moduli > 375 GPa, high fracture strengths (> 1 GPa) that are retained to greater than or equal to 900 degrees C, and fracture toughness values 10 MPa root m. The thermal diffusivity at 200 degrees C for the composites is similar to 0.070 to 0.075 cm(2) s(-1) while the thermal expansion coefficient rises with Ni3Al content from similar to 8 to similar to 11 x 10(-6) K-1 over the range of 8 to 40 vol% Ni3Al. The oxidation and acidic corrosion resistances appear to be promising as well. Finally, they also exhibit good electrical conductivity allowing them to be sectioned and shaped by electrical discharge machining (EDM) processes. (C) 1998 Published by Elsevier Science Limited. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Becher, PF (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. NR 19 TC 18 Z9 19 U1 1 U2 12 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 1998 VL 18 IS 4 BP 395 EP 400 DI 10.1016/S0955-2219(97)00124-6 PG 6 WC Materials Science, Ceramics SC Materials Science GA ZF256 UT WOS:000072879300016 ER PT J AU Thomas, G Gopal, M AF Thomas, G Gopal, M TI Electron microscopy and microanalysis of advanced materials SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT Symposium on Powder Characterisation for Advanced Materials Manufacture CY JUN 16-20, 1997 CL GIJON, SPAIN SP CSIC, Ayuntamiento Gijon, Comis Interministerial Ciencia & Tecnol, Fdn Invest Cientif & Tecn, Principado Asturias, Soc Espanola Ceram & Vidrio ID SILICON-NITRIDE CERAMICS; MULLITE WHISKERS; PHASE; COMPOSITES; BEHAVIOR; STRENGTH AB The characterization of advanced ceramics requires the application of advanced electron microscopy,, diffraction and microanalysis. Examples are given here of high resolution (atomic) imaging and microanalysis sis by energy loss spectroscopy together with their main limitations. These limitations inevitably refer to instrumentation capabilities, and especially the quality? and thinness restrictions of specimens. Examples are presented of atomic resolution for structure analysis of nanostructure/fiber ceramics and parallel energy loss spectroscopy and energy filtering for evaluating processing problems in BN-SiC fiber composites. (C) 1998 Elsevier Science Limited. All rights reserved. C1 Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. RP Thomas, G (reprint author), Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. NR 26 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 1998 VL 18 IS 9 BP 1227 EP 1234 DI 10.1016/S0955-2219(98)00047-8 PG 8 WC Materials Science, Ceramics SC Materials Science GA 116VG UT WOS:000075745300014 ER PT J AU Tomsia, AP Saiz, E Ishibashi, H Diaz, M Requena, J Moya, JS AF Tomsia, AP Saiz, E Ishibashi, H Diaz, M Requena, J Moya, JS TI Powder processing of mullite/Mo functionally graded materials SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT Symposium on Powder Characterisation for Advanced Materials Manufacture CY JUN 16-20, 1997 CL GIJON, SPAIN SP CSIC, Ayuntamiento Gijon, Comis Interministerial Ciencia & Tecnol, Fdn Invest Cientif & Tecn, Principado Asturias, Soc Espanola Ceram & Vidrio ID MOLYBDENUM; FRACTURE AB Graded or layered materials have been used for many years in specific applications to improve reliability for bonds between dissimilar materials, for improved coating adherence and to obtain better compatibility between fibers and matrices ices in composites. Recently, the concept has been formalized en, and such materials entitled FGMs. Molybdenum and mullite are two ideal candidates to fabricate ceramic/metal composites and FGMs because of their similarity in thermal expansion, lack of reactivity at high temperature and high refractoriness. In the present work a systematic investigation of powder processing for the fabrication of mullite/Mo FGMs is described. it,vas found that the processing of mullite/Mo in water resulted in a formation of a homogeneous composite, whereas mixtures processed in ethyl alcohol produced FGMs with continuous gradient. Compositional gradients, fracture toughness, hardness and Electrical conductivity of the FGMs were also evaluated. (C) 1998 Elsevier Science Limited All rights reserved. C1 Lawrence Berkeley Natl Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. TOTO Ltd, Kitakyushu, Fukuoka, Japan. CSIC, Inst Ciencia Mat, E-28049 Madrid, Spain. RP Tomsia, AP (reprint author), Lawrence Berkeley Natl Lab, Ctr Adv Mat, 1 Cyclotron Rd,MS 62-203, Berkeley, CA 94720 USA. RI Moya, Jose/I-5841-2013; Diaz, Marcos/G-5925-2014 OI Diaz, Marcos/0000-0001-7751-4913 NR 16 TC 43 Z9 43 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 1998 VL 18 IS 9 BP 1365 EP 1371 DI 10.1016/S0955-2219(98)00066-1 PG 7 WC Materials Science, Ceramics SC Materials Science GA 116VG UT WOS:000075745300033 ER PT J AU Petot, C Filal, M Rizea, AD Westmacott, KH Laval, JY Lacour, C Ollitrault, R AF Petot, C Filal, M Rizea, AD Westmacott, KH Laval, JY Lacour, C Ollitrault, R TI Microstructure and ionic conductivity of freeze-dried yttria-doped zirconia SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article ID STABILIZED ZIRCONIA; CERAMICS; IMPEDANCE AB The relationship between the microstructure and ionic conductivity of 9 mol% yttria-doped zirconia is deduced from a comparative study per;formed on polycrystalline samples prepared either from commercial powder (sample Z(C)) or from freeze-dried powder (sample Z(F)). The grain boundary ionic conductivity of the Z(F) samples increases with the sintering temperature and this effect is due both to an increase in grain size and to a decrease in the number of glassy triple points. Furthermore, the grain boundary conductivity of the Z(F) sample is 30 times higher than that of the Z(C) sample sintered in the same conditions and with the same grain size. From the microstructural characterizations, it is concluded that this effect is due to the poor microstructure of the Z(C) sample and in particular to the presence of a glassy film on a large number of grain boundaries. On the centrally, the microstructure of the Z(F) samples is cleaner and more homogeneous with larger lens-shaped glassy pockets at triple points and no evidence for continuous boundary films. In spite of the differences in the Z(F) and Z(C) microstructure the activation energy for the grain boundary conductivity is the same; this is consistent with a partially-wetted grain boundary model in which conductivity occurs across unwetted grains in direct contact. A comparison with recent work on other Y2O3-compositions shows excellent agreement. (C) 1998 Elsevier Science Limited All rights reserved. C1 Ecole Cent Paris, Chim Phys Solide Lab, CNRS URA 453, F-92295 Chatenay Malabry, France. Ecole Super Phys & Chim Ind, CNRS UPR 5, Phys Solides Lab, F-75231 Paris 05, France. Ecole Super Phys & Chim Ind, CNRS, Lab Ceram & Mat Mineraux, F-75231 Paris 05, France. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Petot, C (reprint author), Ecole Cent Paris, Chim Phys Solide Lab, CNRS URA 453, Grande Voie des Vignes, F-92295 Chatenay Malabry, France. RI Alin Daniel, Rizea/C-6616-2015 OI Alin Daniel, Rizea/0000-0001-8451-7071 NR 28 TC 22 Z9 22 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 1998 VL 18 IS 10 BP 1419 EP 1428 DI 10.1016/S0955-2219(98)00024-7 PG 10 WC Materials Science, Ceramics SC Materials Science GA 116PG UT WOS:000075733300006 ER PT J AU Suganuma, K Saiz, E Tomsia, AP AF Suganuma, K Saiz, E Tomsia, AP TI Microstructure and strength of interface between pure aluminum and alpha-alumina SO JOURNAL OF THE JAPAN INSTITUTE OF METALS LA Japanese DT Article DE alumina; aluminum; interface; strength; microstructure; sapphire ID COMPOSITES; CERAMICS; METALS AB The interface strength and microstructure of alpha-alumina/pure aluminum were evaluated. In a solid-state joining, the strength of the joint increases with increasing joining temperature. In a liquid state joining, the strength gradually decreases due to the formation of an unjoined area. The strength, sigma(b), is expressed by the following equation as a function of the unjoined area, A,: sigma(b) = 2.22A + 143 (70%less than or equal to A less than or equal to 100%). The highest strength reached 400 MPa when the interface is formed at around the melting temperature of aluminum. An aluminum layer becomes a single crystal when it is joined to a sapphire. The following crystallographic orientation relationship is established: ((1) over bar 11)(Al)//(001)(alpha-Al2O3), [110](Al)//[100](alpha-Al2O3) Amorphous alumina islands are formed at the interface. In the amorphous alumina, spinel nano crystals grow from the sapphire and they have the same orientation relationship with sapphire as above. C1 Osaka Univ, Inst Sci & Ind Res, Ibaraki, Osaka 567, Japan. Univ Calif Berkeley, Lawrence Berkeley Labs, Berkeley, CA 94720 USA. RP Suganuma, K (reprint author), Osaka Univ, Inst Sci & Ind Res, 8-1 Mihogaoka, Ibaraki, Osaka 567, Japan. NR 13 TC 6 Z9 6 U1 1 U2 3 PU JAPAN INST METALS PI SENDAI PA 1-14-32, ICHIBANCHO, AOBA-KU, SENDAI, 980-8544, JAPAN SN 0021-4876 EI 1880-6880 J9 J JPN I MET JI J. Jpn. Inst. Met. PD JAN PY 1998 VL 62 IS 1 BP 92 EP 97 PG 6 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA ZD376 UT WOS:000072679000014 ER PT J AU Milonni, PW Fugate, RQ Telle, JM AF Milonni, PW Fugate, RQ Telle, JM TI Analysis of measured photon returns from sodium beacons SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID LASER-GUIDE-STAR; ADAPTIVE-OPTICS; MESOSPHERIC SODIUM; PERFORMANCE; ASTRONOMY; LAYER; EXCITATION; TELESCOPES; FREQUENCY; SYSTEMS AB We describe an approach to the computation of photon returns from mesospheric sodium beacons excited by laser pulse trains and discuss as specific examples the required numbers of photons for adaptive-optical compensation of atmospheric turbulence. Computed photon return signals are compared with reported measurements for pulses that are long, short, or comparable to the D-2 radiative lifetime (16 ns). Analytical approximations in good agreement with the numerical computations are derived. The results are consistent with experimental data for the different pulse durations. (C) 1998 Optical Society of America. C1 Univ Calif Los Alamos Natl Lab, Atom & Opt Theory Grp T 4, Los Alamos, NM 87545 USA. USAF, Res Lab, Starfire Opt Range, Kirtland AFB, NM 87117 USA. RP Milonni, PW (reprint author), Univ Calif Los Alamos Natl Lab, Atom & Opt Theory Grp T 4, POB 1663, Los Alamos, NM 87545 USA. NR 38 TC 46 Z9 47 U1 2 U2 8 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD JAN PY 1998 VL 15 IS 1 BP 217 EP 233 DI 10.1364/JOSAA.15.000217 PG 17 WC Optics SC Optics GA YQ744 UT WOS:000071418900023 ER PT J AU Smith, AV Armstrong, DJ Alford, WJ AF Smith, AV Armstrong, DJ Alford, WJ TI Increased acceptance bandwidths in optical frequency conversion by use of multiple walk-off-compensating nonlinear crystals SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID 2ND HARMONIC-GENERATION; 2ND-HARMONIC GENERATION; HIGH-EFFICIENCY; SUM-FREQUENCY; BETA-BAB2O4; KTIOPO4; AGGASE2; SINGLE; CAVITY; PULSES AB We show by experiment and mathematical model that angular and frequency acceptance bandwidths for frequency mixing in a nonlinear crystal can often be improved by segmenting the crystal and reversing the spatial or temporal walk-off in alternating segments. We analyze nonlinear mixing primarily in real space, (x, t), rather than Fourier space, (k, omega), and show that acceptance bands for sum-and difference-frequency mixing can be increased by up to a factor equal to the number of crystal segments. We consider both high-and low-efficiency mixing as well as parametric gain, and show that in many cases of practical interest the increased bandwidth substantially improves conversion efficiency. We also attempt to clarify the role of acceptance bandwidths in frequency mixing. (C) 1998 Optical Society of America. C1 Sandia Natl Labs, Dept Lasers Opt & Remote Sensing, Albuquerque, NM 87185 USA. RP Smith, AV (reprint author), Sandia Natl Labs, Dept Lasers Opt & Remote Sensing, Albuquerque, NM 87185 USA. NR 35 TC 66 Z9 70 U1 6 U2 16 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD JAN PY 1998 VL 15 IS 1 BP 122 EP 141 DI 10.1364/JOSAB.15.000122 PG 20 WC Optics SC Optics GA YT825 UT WOS:000071648800017 ER PT J AU Hubbard, SF Petschek, RG Singer, KD D'Sidocky, N Hudson, C Chien, LC Henderson, CC Cahill, PA AF Hubbard, SF Petschek, RG Singer, KD D'Sidocky, N Hudson, C Chien, LC Henderson, CC Cahill, PA TI Measurements of Kleinman-disallowed hyperpolarizability in conjugated chiral molecules SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID HYPER-RAYLEIGH-SCATTERING; NONLINEAR-OPTICAL PROPERTIES; 2ND-HARMONIC GENERATION; LIGHT-SCATTERING; SYSTEMS; TENSOR; MEDIA AB We have designed a hyper-Rayleigh scattering scheme to measure six scalar invariants of the squared hyperpolarizability tensor beta(2). OUT theoretical approach expresses the rotational invariants of the irreducible beta components as scalars, which eliminates the need for difficult frame transformations. We applied our scheme to several conjugated chiral molecules and found that there are significant Kleinman-disallowed pseudotensor contributions to their hyperpolarizability. These components, along with a large optical rotation and the results of quantum-chemical calculations, indicate a handed nonplanar delocalization of the charge-transfer system in such molecules as predicted by quantum-chemical calculations and are expected to lead to macroscopic second-harmonic generation in axially aligned polymer materials. Pseudotensor contributions to the hyperpolarizability in chiral molecules were found to be as large as the vector contribution in p-nitroaniline. We qualitatively investigated the dispersion in the Kleinman-disallowed components and confirmed that these components are smaller at longer wavelengths. (C) 1998 Optical Society of America. C1 Case Western Reserve Univ, Dept Phys, Cleveland, OH 44106 USA. Kent State Univ, Inst Liquid Crystal, Kent, OH 44242 USA. Sandia Natl Labs, Livermore, CA 94551 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hubbard, SF (reprint author), Case Western Reserve Univ, Dept Phys, Cleveland, OH 44106 USA. RI Singer, Kenneth/G-6553-2011 NR 45 TC 37 Z9 37 U1 2 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD JAN PY 1998 VL 15 IS 1 BP 289 EP 301 DI 10.1364/JOSAB.15.000289 PG 13 WC Optics SC Optics GA YT825 UT WOS:000071648800036 ER PT J AU Saini, NL Lanzara, A Bianconi, A Chou, FC Johnston, DC AF Saini, NL Lanzara, A Bianconi, A Chou, FC Johnston, DC TI Study of Cu-O and Cu-La pair correlations in superconducting La2CuO4.1 system by Cu K-edge EXAFS SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Letter DE lattice instabilities; High T-c superconductors; synchrotron radiation spectroscopy ID ABSORPTION FINE-STRUCTURE; LA2CUO4+DELTA; PLANE; GAP AB We report Cu K-edge extended X-ray absorption fine structure (EXAFS) spectra up to high momentum transfer measured on a superconducting La2CuO4.1 single crystal using in-plane polarization of synchrotron light. The EXAFS data with a high signal to noise ratio has enabled the precise determination of the Debye-Waller factors and the pair correlations of Cu-O (planar) and Cu-La pairs of the structurally complex superconducting system. We have observed an anomalous behaviour of the pair correlations at similar to 170 K and attributed it to an interplay between temperature-dependent structural modulation of the perovskite and rock-salt layers in the title compound. C1 Univ Rome La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Univ Rome La Sapienza, INFM, I-00185 Rome, Italy. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Saini, NL (reprint author), Univ Rome La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. RI Bianconi, Antonio/J-3997-2013; Saini, Naurang/J-7918-2013 OI Bianconi, Antonio/0000-0001-9795-3913; Saini, Naurang/0000-0003-3684-1517 NR 20 TC 3 Z9 3 U1 2 U2 4 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD JAN PY 1998 VL 67 IS 1 BP 16 EP 19 DI 10.1143/JPSJ.67.16 PG 4 WC Physics, Multidisciplinary SC Physics GA YU914 UT WOS:000071769300005 ER PT J AU Asai, K Yoneda, A Yokokura, O Tranquada, JM Shirane, G AF Asai, K Yoneda, A Yokokura, O Tranquada, JM Shirane, G TI Two spin-state transitions in LaCoO3 SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE two spin-state transitions; low spin; intermediate spin; high spin; magnetovolume effect; lanthanum cobalt oxide; LaCoO3 ID SEMICONDUCTOR-METAL TRANSITION; ELECTRONIC-STRUCTURE; BAND-STRUCTURE; PEROVSKITE; LA1-XSRXCOO3; SPECTROSCOPY; EQUILIBRIA; OXIDES; MODEL AB Neutron-diffraction measurements have revealed a new anomalous thermal lattice expansion of LaCoO3 near 500 K that indicates the existence of a second spin-state transition; in addition to the one previously established near 100 K. The anomalous expansion and the temperature dependence of the Co magnetic moments are successfully interpreted in a wide temperature range based on a simple model assuming low-spin (LS, S = 0); intermediate-spin (IS, S = 1), and high-spin (HS, S = 2) states of Co atoms. The first spin transition, near 100 K, is from LS to IS, and the second, near 500 K. is hom IS to a mixed state of IS and HS. The fitted model parameters indicate that the initially-large energy difference between IS and HS states decreases towards zero as the second transition proceeds. The large drop in resistivity associated with the latter transition appears to be correlated with the population of the HS state. C1 Univ Electrocommun, Dept Appl Phys & Chem, Tokyo 182, Japan. Brookhaven Natl Lab, Upton, NY 11973 USA. Waseda Univ, Dept Phys, Tokyo 169, Japan. RP Asai, K (reprint author), Univ Electrocommun, Dept Appl Phys & Chem, Tokyo 182, Japan. RI Tranquada, John/A-9832-2009 OI Tranquada, John/0000-0003-4984-8857 NR 33 TC 260 Z9 260 U1 4 U2 51 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD JAN PY 1998 VL 67 IS 1 BP 290 EP 296 DI 10.1143/JPSJ.67.290 PG 7 WC Physics, Multidisciplinary SC Physics GA YU914 UT WOS:000071769300054 ER PT J AU Atkinson, AC Wakefield, J Nelder, JA Longford, NT Draper, D Critchley, F Davison, AC Leonard, T Christensen, R Cox, DR Solomon, PJ Fung, WK Gu, H Gelman, A Price, PN Pan, JX Sargent, DJ Whittaker, J AF Atkinson, AC Wakefield, J Nelder, JA Longford, NT Draper, D Critchley, F Davison, AC Leonard, T Christensen, R Cox, DR Solomon, PJ Fung, WK Gu, H Gelman, A Price, PN Pan, JX Sargent, DJ Whittaker, J TI Some algebra and geometry for hierarchical models, applied to diagnostics - Discussion SO JOURNAL OF THE ROYAL STATISTICAL SOCIETY SERIES B-STATISTICAL METHODOLOGY LA English DT Editorial Material ID POPULATION PHARMACOKINETIC MODELS; GENERALIZED LINEAR-MODELS; DELETION DIAGNOSTICS; MULTIPLE OUTLIERS; MIXED MODELS; COMPONENTS; REGRESSION; COVARIANCE; VARIANCE; TRANSFORMATIONS C1 Univ London London Sch Econ & Polit Sci, London WC2A 2AE, England. Univ London Imperial Coll Sci Technol & Med, London SW7 2AZ, England. De Montfort Univ, Leicester LE1 9BH, Leics, England. Univ Bath, Bath BA2 7AY, Avon, England. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Swiss Fed Inst Technol, Lausanne, Switzerland. Univ Edinburgh, Edinburgh EH8 9YL, Midlothian, Scotland. Univ Oxford Nuffield Coll, Oxford OX1 1NF, England. Univ Adelaide, Adelaide, SA 5005, Australia. Univ Hong Kong, Hong Kong, Peoples R China. Columbia Univ, New York, NY USA. Lawrence Berkeley Natl Lab, Berkeley, CA USA. Rothamsted Expt Stn, Harpenden AL5 2JQ, Herts, England. Mayo Clin, Rochester, MN USA. Univ Lancaster, Lancaster LA1 4YW, England. RP Atkinson, AC (reprint author), Univ London London Sch Econ & Polit Sci, London WC2A 2AE, England. NR 57 TC 6 Z9 6 U1 1 U2 2 PU BLACKWELL PUBL LTD PI OXFORD PA 108 COWLEY RD, OXFORD OX4 1JF, OXON, ENGLAND SN 1369-7412 J9 J ROY STAT SOC B JI J. R. Stat. Soc. Ser. B-Stat. Methodol. PY 1998 VL 60 BP 521 EP 536 PN 3 PG 16 WC Statistics & Probability SC Mathematics GA ZR600 UT WOS:000073994800002 ER PT J AU Webster, R Lawson, AB Glasbey, C Horgan, G Elston, D Host, G Mugglestone, MA Kenward, MG Kent, JT Stein, A Clifford, P Ledford, AW Marriott, PK Aitkin, M Atkinson, AC Boskov, M Kelsall, J Wakefield, J Bowman, A Casson, E Cressie, N Denison, DGT Mallick, BK Dixon, P Scott, M Haas, TC Handcock, MS Holmes, CC Laslett, G Lele, S Nadarajah, S O'Hagan, A Pettitt, AN Hay, J Richardson, S Stein, M Stoyan, D Williams, CKI AF Webster, R Lawson, AB Glasbey, C Horgan, G Elston, D Host, G Mugglestone, MA Kenward, MG Kent, JT Stein, A Clifford, P Ledford, AW Marriott, PK Aitkin, M Atkinson, AC Boskov, M Kelsall, J Wakefield, J Bowman, A Casson, E Cressie, N Denison, DGT Mallick, BK Dixon, P Scott, M Haas, TC Handcock, MS Holmes, CC Laslett, G Lele, S Nadarajah, S O'Hagan, A Pettitt, AN Hay, J Richardson, S Stein, M Stoyan, D Williams, CKI TI Model-based geostatistics - Discussion SO JOURNAL OF THE ROYAL STATISTICAL SOCIETY SERIES C-APPLIED STATISTICS LA English DT Editorial Material ID PREDICTIVE PERFORMANCE; BAYESIAN-ANALYSIS; STATISTICS; REGRESSION; OPTIMIZATION; UNCERTAINTY; DISEASE; SPLINES; RISK C1 Rothamsted Expt Stn, Harpenden AL5 2JQ, Herts, England. Univ Abertay, Dundee, Scotland. Biomath & Stat Scotland, Edinburgh, Midlothian, Scotland. IACR Rothamsted, Harpenden, Herts, England. Univ Kent, Canterbury, Kent, England. Int Inst Aerosp Survey & Earth Sci, Enschede, Netherlands. Wageningen Univ Agr, Wageningen, Netherlands. Univ Surrey, Guildford GU2 5XH, Surrey, England. Univ London London Sch Econ & Polit Sci, London WC2A 2AE, England. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. Univ Lancaster, Lancaster LA1 4YW, England. Iowa State Univ, Ames, IA 50011 USA. Univ London Imperial Coll Sci Technol & Med, London, England. Savannah River Ecol Lab, Aiken, SC USA. Univ Wisconsin, Milwaukee, WI 53201 USA. Penn State Univ, University Pk, PA 16802 USA. CSIRO, Clayton, Vic 3168, Australia. Johns Hopkins Univ, Baltimore, MD USA. Univ Nottingham, Nottingham NG7 2RD, England. Queensland Univ Technol, Brisbane, Qld, Australia. INSERM, Villejuif, France. Univ Chicago, Chicago, IL 60637 USA. Freiberg Univ Min & Technol, Freiberg, Germany. Aston Univ, Birmingham B4 7ET, W Midlands, England. RP Rothamsted Expt Stn, Harpenden AL5 2JQ, Herts, England. RI Cressie, Noel/B-8858-2009; Elston, David/H-8199-2013; Horgan, Graham/J-3738-2013; O'Hagan, Anthony/B-2992-2016; Stein, Alfred/D-4731-2009 OI Cressie, Noel/0000-0002-0274-8050; O'Hagan, Anthony/0000-0002-7994-0702; Stein, Alfred/0000-0002-9456-1233 NR 75 TC 0 Z9 0 U1 0 U2 10 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0035-9254 EI 1467-9876 J9 J R STAT SOC C-APPL JI J. R. Stat. Soc. Ser. C-Appl. Stat. PY 1998 VL 47 BP 326 EP 350 PN 3 PG 25 WC Statistics & Probability SC Mathematics GA 124WR UT WOS:000076206200002 ER PT J AU Baur, H Wunderlich, B AF Baur, H Wunderlich, B TI About complex heat capacities and temperature-modulated calorimetry SO JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY LA English DT Article DE complex heat capacity; heat capacity; irreversible thermodynamics; temperature-modulated calorimetry ID DIFFERENTIAL SCANNING CALORIMETRY; GLASS-TRANSITION REGION; THERMOSETTING SYSTEMS; POLYMER CRYSTALS; DSC; VITRIFICATION; MODEL; CURE AB With increasing use of temperature-modulated calorimetry, TMC, it is has been proposed to use a complex heat capacity for the description of the response of samples to periodic temperature changes. In this article the ramifications of this approach are discussed on the basis of irreversible thermodynamics. Experimental results are summarized which describe heat capacities of liquids and solids, as well as TMC during transitions. It is concluded that the complex hear capacity is of limited value. Solids and liquids have no dissipative (imaginary) contributions. In the glass transition, the thermal response is nonlinear, so that a detailed kinetic model (in real notation) is more advantageous to describe the heat capacity. The crystallization is often so far from equilibrium that it is not modulated. During melting and chemical reactions the heat flow is frequently so large, that steady state is lost and complex heat capacity is of questionable value, even if modulation is accomplished. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Baur, H (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 40 TC 17 Z9 17 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1418-2874 J9 J THERM ANAL CALORIM JI J. Therm. Anal. PY 1998 VL 54 IS 2 BP 437 EP 465 DI 10.1023/A:1010126005720 PG 29 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA 161CJ UT WOS:000078270500004 ER PT J AU Boller, A Ribeiro, M Wunderlich, B AF Boller, A Ribeiro, M Wunderlich, B TI A detailed comparison of first order transitions by DSC and TMC SO JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY LA English DT Article; Proceedings Paper CT 25th North American Thermal Analysis Conference CY SEP 07-09, 1997 CL MCLEAN, VIRGINIA DE frequency domain; heat-flux calorimeter; indium; integral analysis; melting transition; pseudo-isothermal analysis; quasi-isothermal measurement; reversible melting; saw-tooth modulation; sinusoidal modulation; temperature-modulated calorimetry; time-domain ID DIFFERENTIAL SCANNING CALORIMETRY; POWER COMPENSATION DSC; TEMPERATURE CALIBRATION; POLYMER CRYSTALS; HEAT-CAPACITY AB Indium was analyzed with both, standard differential scanning calorimetry (DSC) and temperature-modulated DSC (TMDSC) using sinusoidal and saw-tooth modulation. Instrument and sample effects were separated during nucleated, reversible melting and crystallization transitions, and irreversible crystallization with supercooling. The changes in heat flow, time, and sample and reference temperatures were correlated as functions of heating rate, mass, and modulation parameters. The transitions involve three regions of steady state (an initial and a final region before and after melting/crystallization, a region while melting/crystallization is in progress) and one region of approach to steady state (melting peak to final steady state region). Analyses in the time domain show promise when instrument lags, known from DSC, are used for correction of TMDSC A new method of integral analysis is introduced for quantitative analysis even when irreversible processes occur in addition to reversible transitions. The information was derived from heat-flux calorimeters with control at the heater block or at the reference temperature sensor. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Boller, A (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 27 TC 15 Z9 15 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1418-2874 J9 J THERM ANAL CALORIM JI J. Therm. Anal. PY 1998 VL 54 IS 2 BP 545 EP 563 DI 10.1023/A:1010190425284 PG 19 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA 161CJ UT WOS:000078270500010 ER PT J AU Pyda, M Bartkowiak, M Wunderlich, B AF Pyda, M Bartkowiak, M Wunderlich, B TI Computation of heat capacities of solids using a general Tarasov equation SO JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY LA English DT Article DE diamond; fullerene; graphite; heat capacity; polyethylene; poly(ethylene terephthalate); polypropylene; selenium; solid state; Tarasov equation; vibrational spectra ID LINEAR MACROMOLECULES; THERMODYNAMIC PROPERTIES; SKELETAL VIBRATIONS; POLYMERS; BUCKMINSTERFULLERENE; SPECTRA; CARBON; MODES AB The general Tarasov function is fitted to the skeletal heat capacities of materials with widely different crystal structures. Examples are chosen from flexible macromolecules (polyethylene, polypropylene, poly(ethylene terephthalate), selenium, rigid macromolecules (diamond and graphite), and a small molecule (fullerene, C-60). A new optimization approach using the Mathematica(TM) software is developed. It results in one-, two-, and three-dimensional Debye temperatures, Theta(1), Theta(2) and Theta(3) the fitting parameters of the Tarasov function. In addition to the Tarasov function, the evaluation of the heat capacities makes use of approximate group-vibrational spectra. The results support the earlier assumption that Theta(2)=Theta(3) for simple, solid, linear macromolecules. In more complicated bonding situations, Theta(1), Theta(2) and Theta(3) are used as averaging fitting parameters. This general approach provides an improvement in the quantitative thermal analyses of polymers and other substances included in the ATHAS Data Bank. Sufficient programming information is provided to enable anyone the computation with a copy of the popular Mathematica(TM) software. The programming file is also downloadable from the WWW. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Wunderlich, B (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 48 TC 42 Z9 42 U1 1 U2 11 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0368-4466 J9 J THERM ANAL CALORIM JI J. Therm. Anal. PY 1998 VL 52 IS 2 BP 631 EP 656 DI 10.1023/A:1010188110516 PG 26 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA 135XE UT WOS:000076827400038 ER PT J AU Fowler, JS Volkow, ND AF Fowler, JS Volkow, ND TI PET imaging studies in drug abuse SO JOURNAL OF TOXICOLOGY-CLINICAL TOXICOLOGY LA English DT Review ID POSITRON EMISSION TOMOGRAPHY; BRAIN GLUCOSE-METABOLISM; CEREBRAL BLOOD-FLOW; PLATELET MONOAMINE-OXIDASE; CIGARETTE SMOKERS; DOPAMINE TRANSPORTER; ALCOHOL-INTOXICATION; COCAINE ABUSERS; BABOON BRAIN; INHIBITION AB In spite of the massive public health problem associated with drug abuse, effective treatments remain elusive. This is due in part to a relatively poor understanding of the neurochemical changes which drugs of abuse produce in the human brain and the relationship of these changes to the behavioral and addictive properties of drugs. With the development of modern imaging methods and a variety of labeled drugs and radiotracers, it has now become possible to track many aspects of drug pharmacokinetics and pharmacodynamics directly in the human brain and to relate these parameters to the behavioral and toxic properties of drugs. Review: In this article, we will highlight some examples of the use of Positron Emission Tomography to measure drug pharmacokinetics and pharmacodynamics and their relationship to addiction and to toxicity. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. RP Fowler, JS (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM fowler@bnl.gov FU NIDA NIH HHS [R0I DA-06891, R0I DA-06278, R0I DA-09490] NR 77 TC 14 Z9 15 U1 0 U2 2 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0731-3810 J9 J TOXICOL-CLIN TOXIC JI J. Toxicol.-Clin. Toxicol. PY 1998 VL 36 IS 3 BP 163 EP 174 PG 12 WC Toxicology SC Toxicology GA ZX871 UT WOS:000074563800001 PM 9656971 ER PT J AU vantWout, AB Ran, LJ Kuiken, CL Kootstra, NA Pals, ST Schuitemaker, H AF vantWout, AB Ran, LJ Kuiken, CL Kootstra, NA Pals, ST Schuitemaker, H TI Analysis of the temporal relationship between human immunodeficiency virus type 1 quasispecies in sequential blood samples and various organs obtained at autopsy SO JOURNAL OF VIROLOGY LA English DT Article ID SYNCYTIUM-INDUCING PHENOTYPE; HIV-1 INFECTION; CEREBROSPINAL-FLUID; ENVELOPE PROTEIN; LYMPHOID-TISSUE; VIRAL BURDEN; AIDS; PROGRESSION; SEQUENCES; DISEASE AB We studied the temporal relationship between human immunodeficiency type 1 (HIV-1) quasispecies in tissues and in peripheral blood mononuclear cells (PBMC) of infected individuals. Sequential PBMC and tissue samples from various organs obtained at autopsy from three patients who died of AIDS-related complications were available for analysis. Biological HIV-1 clones were isolated from PBMC samples, and cellular tropism and syncytium-inducing (SI) capacity were determined. Genomic DNA,vas isolated from 1 cm(3) of organ tissue, and proviral DNA was amplified by means of PCR and cloned with the PGEM-T vector system. A 185-bp region encompassing the third variable domain of the virus envelope, known to influence HIV-1 biological properties, was sequenced. HIV-1 could be amplified from all PBMC and organ samples, except from liver tissue for two patients. Both SI and non-syncytium-inducing (NSI) genotypes could be detected in the different tissues. Tissue-specific quasispecies were observed in brain, lung, and testis. Lymphoid tissues, such as bone marrow, lymph node, and spleen, harbored several different variants similar to those detected in blood in the last PBMC samples. In general, only tissues in which macrophages are likely to be the main target cell for HIV-1 harbored NSI HIV-1 sequences that clustered separately. Both SI and NSI sequences that clustered with sequences from late-stage PBMC were present in other tissues, which may indicate that the presence of PIN-1 in those tissues is secondary to lymphocyte infiltration rather than to tissue tropism of HIV-1 itself. These data suggest that the viral reservoir may be limited, which will have important implications for the success of HIV-1 eradication. C1 NETHERLANDS RED CROSS,BLOOD TRANSFUS SERV,CENT LAB,DEPT CLIN VIROIMMUNOL,NL-1066 CX AMSTERDAM,NETHERLANDS. UNIV AMSTERDAM,EXPT & CLIN IMMUNOL LAB,AMSTERDAM,NETHERLANDS. UNIV AMSTERDAM,ACAD MED CTR,DEPT PATHOL,NL-1105 AZ AMSTERDAM,NETHERLANDS. LOS ALAMOS NATL LAB,HIV DATABASE & ANAL GRP,LOS ALAMOS,NM. NR 59 TC 108 Z9 109 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0022-538X J9 J VIROL JI J. Virol. PD JAN PY 1998 VL 72 IS 1 BP 488 EP 496 PG 9 WC Virology SC Virology GA YL010 UT WOS:A1998YL01000057 PM 9420250 ER PT J AU Fedynich, AM Bryan, AL Harris, MJ AF Fedynich, AM Bryan, AL Harris, MJ TI Hematozoa in the endangered wood stork from Georgia SO JOURNAL OF WILDLIFE DISEASES LA English DT Article DE endangered species; Haemoproteus crumenium; haemoproteid; hematozoa; Mycteria americana; survey; wood stork ID HAEMOPROTEIDS; CICONIIDAE AB Thin blood smears of 75 wood storks (Mycteria americana) from Georgia (USA) were made during the summers of 1994-96 and examined for blood parasites. Haemoproteus crumenium was found in one of 71 juveniles and in two adults from a sample of two subadults and two adults. Intensity of infection in the juvenile and in each of the two adults was 11, 3, and 2 parasites/5,000 erythrocytes, respectively. This is the first record of H. crumenium in the wood stork from Georgia and the second published record of H. crumenium infecting this host in North America. Additionally, one juvenile was infected with a microfilarid. C1 Texas A&M Univ, Caesar Kleberg Wildlife Res Inst, Kingsville, TX 78363 USA. Savannah River Ecol Lab, Aiken, SC 29802 USA. Georgia Dept Nat Resources, Nongame Endangered Wildlife Program, Brunswick, GA USA. RP Fedynich, AM (reprint author), Texas A&M Univ, Caesar Kleberg Wildlife Res Inst, Campus Box 218, Kingsville, TX 78363 USA. NR 8 TC 3 Z9 3 U1 0 U2 0 PU WILDLIFE DISEASE ASSN, INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 USA SN 0090-3558 J9 J WILDLIFE DIS JI J. Wildl. Dis. PD JAN PY 1998 VL 34 IS 1 BP 165 EP 167 PG 3 WC Veterinary Sciences SC Veterinary Sciences GA YU630 UT WOS:000071737800022 PM 9476241 ER PT J AU Heilmann, TJ Garrott, RA Cadwell, LL Tiller, BL AF Heilmann, TJ Garrott, RA Cadwell, LL Tiller, BL TI Behavioral response of free-ranging elk treated with an immunocontraceptive vaccine SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE breeding; Cervus elaphus; estrus; immunocontraception; porcine zona pellucida; PZP; reproduction; Washington ID REMOTELY-DELIVERED IMMUNOCONTRACEPTION; FERTILITY-CONTROL; CONTRACEPTION; MANAGEMENT; POPULATIONS; DEER AB Most wildlife contraceptive studies to date have evaluated treatment efficacy on individuals, but little research has evaluated the potential behavioral effects associated with inhibiting conception in polyestrous species. During autumn 1993 and 1994, we compared the behavior of 10 free-ranging, radiocollared cow elk (Cervus elaphus) vaccinated with porcine zona pellucida (PZP) immunocontraceptive vaccine with 10 unvaccinated cow elk. We tested the hypothesis that breeding behavior would be prolonged in PZP-treated cows due to repeated estrus cycling. Sexual interaction rates of treatment and control cows were similar during the normal breeding season (P = 0.96) but differed significantly during the postbreeding season (P < 0.001), when almost no sexual interactions were observed in control cows. Postbreeding season interaction rates in treated cows remained at the level observed during the breeding season. We did not detect any significant changes in activity patterns or social structure of the elk during the postbreeding season as a consequence of the apparent PZP-induced cycling (P > 0.50). It is uncertain whether the results of this study apply to possible effects of PZP treatment for management-level applications where a large proportion of the females would be treated. We recommend population-level experiments to further our understanding of the effects of contraceptive technologies on the behavior and dynamics of free-ranging ungulate herds. C1 Univ Wisconsin, Dept Wildlife Ecol, Madison, WI 53706 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Garrott, RA (reprint author), Univ Wisconsin, Dept Wildlife Ecol, 226 Russell Labs, Madison, WI 53706 USA. EM ubirg@montana.edu NR 33 TC 22 Z9 24 U1 1 U2 2 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 USA SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD JAN PY 1998 VL 62 IS 1 BP 243 EP 250 DI 10.2307/3802284 PG 8 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA YU728 UT WOS:000071748300026 ER PT B AU Neal, JT Bauer, SJ Ehgartner, BL AF Neal, JT Bauer, SJ Ehgartner, BL BE Borchers, JW TI Mine-induced sinkholes over the US Strategic Petroleum Reserve (SPR) storage facility at Weeks Island, Louisiana: Geologic causes and effects SO LAND SUBSIDENCE CASE STUDIES AND CURRENT RESEARCH: PROCEEDINGS OF THE DR. JOSEPH F. POLAND SYMPOSIUM ON LAND SUBSIDENCE SE ASSOCIATION OF ENGINEERING GEOLOGISTS, SPECIAL PUBLICATION LA English DT Proceedings Paper CT Dr Joseph F Poland Symposium on Land Subsidence CY OCT 04-05, 1995 CL SACRAMENTO, CA SP US Geol Survey, California Dept Water Resources, Assoc California Water Agencies, California State Assoc Counties, Ground Water Resources Assoc California, Assoc Engn Geologists, Bur Reclamat, Water Educ Fdn, State Water Resources Control Board AB The initial sinkhole at the Weeks Island Strategic Petroleum Reserve site that was first observed in May 1992 gradually enlarged and deepened, concurrent with the increasing dissolution of salt over the mined oil-storage area below. Beginning in 1994 and continuing to the present, the injection of saturated brine directly into the sinkhole throat some 76 m (250 ft) beneath the surface essentially arrested further dissolution, buying time to make adequate preparation for the safe and orderly transfer of crude oil to other storage facilities. This mitigation measure marked the first time that such a control procedure had been used in salt mining; previously all control has been achieved by in-mine and surface grouting. A second and much smaller sinkhole was first noticed in early 1995 on an opposite edge of the Strategic Petroleum Reserve mine, but with a very similar geological and mine mechanics setting. Both sinkholes occur where the edges of upper -152 m (-500 ft) and lower -213 m (-700 ft) storage levels are nearly vertically aligned. Such coincidence maximizes development of tensional stress, leading to fracturing in the salt. Such cracking takes years to develop, perhaps 20 years or more. The cracks then become flowpaths for brine incursion, wherein after time it is released into mined openings. Undersaturated ground water gradually enlarges the cracks in salt, leading to further dissolution and eventual collapse of the overlying sand to form sinkholes. Other geologic conditions may have been secondary factors in controlling both mining extent and sinkhole location. An en echelon alignment of sinkholes over other mine edges has been observed. Thus, the most likely locations of future sinkholes at Weeks Island are adjacent to the existing sinkholes; surface inspections are now concentrated at those locations. Although neither timing nor location is predictable with precision, the study of numerous sinkholes elsewhere shows that progression is inevitable, provided that relevant conditions and enough time exists for development. These principles should provide mine designers and operators the knowledge to minimize the occurrence of sinkholes, and to plan for their progression when they occur. C1 Sandia Natl Labs, Dept 6113, Albuquerque, NM 87185 USA. RP Neal, JT (reprint author), Sandia Natl Labs, Dept 6113, POB 5800, Albuquerque, NM 87185 USA. NR 22 TC 0 Z9 0 U1 3 U2 3 PU STAR PUBLISHING COMPANY PI BELMONT PA 940 EMMETT AVE, BELMONT, CA 94002 USA BN 0-89863-197-1 J9 ASSOC ENGN GEOLOGIST PY 1998 IS 8 BP 327 EP 336 PG 10 WC Geology SC Geology GA BM36Z UT WOS:000078508600033 ER PT B AU Neal, JT Colpitts, R Johnson, KS AF Neal, JT Colpitts, R Johnson, KS BE Borchers, JW TI Evaporite karst in the Holbrook basin, Arizona SO LAND SUBSIDENCE CASE STUDIES AND CURRENT RESEARCH: PROCEEDINGS OF THE DR. JOSEPH F. POLAND SYMPOSIUM ON LAND SUBSIDENCE SE ASSOCIATION OF ENGINEERING GEOLOGISTS, SPECIAL PUBLICATION LA English DT Proceedings Paper CT Dr Joseph F Poland Symposium on Land Subsidence CY OCT 04-05, 1995 CL SACRAMENTO, CA SP US Geol Survey, California Dept Water Resources, Assoc California Water Agencies, California State Assoc Counties, Ground Water Resources Assoc California, Assoc Engn Geologists, Bur Reclamat, Water Educ Fdn, State Water Resources Control Board AB More than 500 dolines (sinkholes), fissures, depressions, and other karst features occur along an approximately 100-km-long dissolution front developed in evaporite beds of the upper part of the Permian Sedona (formerly Supai) Group. These strata dip northward into the Holbrook basin (previously called the Supai Salt basin). The dissolution front is marked by its coincidence with a structure previously mapped as the Holbrook anticline. The southern flank of the Holbrook anticline dips into an extensive subsidence basin called Dry Lake Valley. The Holbrook anticline likely is a tectonic flexure that has been altered substantially by subsidence and collapse caused by a northward migrating salt-dissolution front. Dissolution is enhanced by runoff into locally enlarged joint-fissures along the anticlinal axis. Three major areas of evaporite karst are present, each with distinctive features: (1) The Sinks, 10 km west northwest of Snowflake, Arizona, contain 250 sinkholes, some up to 200 m in diameter and 50 m deep, and joint-controlled fissures and graben sinks; (2) Dry Lake Valley and contiguous areas where the jointed Moenkopi Formation and Coconino Sandstone contain numerous sinkholes and large collapse fissures, two of which opened and rapidly drained about 6.8 x 10(5) and 7.4 x 10(6) m(3) (550 and 6000 ac-ft, respectively) of water; and (3) McCauley Sinks and contiguous areas, 29 km southeast of Winslow along Chevelon Canyon, contain a localized group of about 50 sinkholes, many showing orthogonal jointing in the surficial Kaibab Formation and underlying Coconino Sandstone. Similar evaporite karst occurs between these three major areas, but is less conspicuous. The variety of karst is distinctive to the Holbrook basin, yet karst landforms are similar to those in other evaporite basins, and to limestone karat. The wide variety of dissolution and collapse features range in development from incipient surface expression to well developed morphology; Karst features presently are forming and new features can. be documented by field studies and on aerial photographs taken only 20 years apart. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Neal, JT (reprint author), 1911 Crestview Trail, Prescott, AZ 86301 USA. NR 35 TC 0 Z9 0 U1 0 U2 0 PU STAR PUBLISHING COMPANY PI BELMONT PA 940 EMMETT AVE, BELMONT, CA 94002 USA BN 0-89863-197-1 J9 ASSOC ENGN GEOLOGIST PY 1998 IS 8 BP 373 EP 384 PG 12 WC Geology SC Geology GA BM36Z UT WOS:000078508600039 ER PT B AU Tucker, DL Hashimoto, Y Kirshner, RP Landy, SD Lin, H Oemler, A Schechter, PL Shectman, SA AF Tucker, DL Hashimoto, Y Kirshner, RP Landy, SD Lin, H Oemler, A Schechter, PL Shectman, SA BE Muller, V Gottlober, S Mucket, JP Wambsganss, J TI Groups of galaxies in the Las Campanas Redshift Survey SO LARGE SCALE STRUCTURE: TRACKS AND TRACES LA English DT Proceedings Paper CT 12th Potsdam Cosmology Workshop on Large Scale Structure - Tracts and Traces CY SEP 15-19, 1997 CL POTSDAM, GERMANY SP Astrophys Inst Postsdam AB A "friends-of-friends" percolation algorithm has been used to extract a catalogue of delta rho/rho = 80 density enhancements (groups) from the six slices of the Las Campanas Redshift Survey (LCRS). The full catalogue contains 1495 groups and includes 35% of the LCRS galaxy sample. A statistical sample of 394 groups has been derived by culling groups from the full sample which either are too close to a slice edge, have a crossing time greater than a Hubble time, have a corrected velocity dispersion of sere or less, or contain a 55 arcsec "orphan" (a galaxy with a "faked" redshift excluded from the original LCRS redshift catalogue due to its proximity - i.e., within 55 arcsec - of another galaxy). Here, in the accompanying table, we compare the median group properties of the full LCRS statistical sample with those of: [1] different LCRS subsamples (groups in the 50-fiber fields, groups in the 112-fiber fields, and groups that straddle a 50-fiber/112-fiber :field border), [2] an earlier LCRS group catalogue, and [3] group catalogues extracted from the Center for Astrophysics Redshift Surveys (CfA1 & CfA2) and the: Southern Sky Redshift Survey (SSRS). C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Tucker, DL (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3499-6 PY 1998 BP 105 EP 106 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL99C UT WOS:000077381700025 ER PT J AU Angelo, P Derfoul, H Gauthier, P Sauvan, P Poquerusse, A Ceccotti, T Leboucher-Dalimier, E Shepard, T Back, C Vollbrecht, M Uschmann, I AF Angelo, P Derfoul, H Gauthier, P Sauvan, P Poquerusse, A Ceccotti, T Leboucher-Dalimier, E Shepard, T Back, C Vollbrecht, M Uschmann, I TI Generation of hot and dense plasmas in laser accelerated colliding foil systems SO LASER AND PARTICLE BEAMS LA English DT Article; Proceedings Paper CT 24th European Conference on Laser Interaction with Matter (ECLIM 96) CY JUN 03-07, 1996 CL MADRID, SPAIN ID CRYSTAL AB We create hot (T-e > 200 eV) and dense (N-e > 10(23) cm(-3)) plasmas in the colliding zone of two thin foils accelerated by two laser beams of the LULI facilities. Three spectroscopic diagnostics (two 1D space-resolved spectrographs and a 2D monochromatic imaging) are used to drive the efficiency of the compression. We show that 2D effects are important. Realistic simulations of these experiments must be done, taking into account the inhomogeneity of the laser intensity in the focal spot, the foil distorsion, the plasma lateral expansion, and the lateral thermal conduction. Two-dimensional LASNEX code results are in good agreement with our experimental results. The optimized compressed plasmas generated are favorable for the exhibition of dense plasma effects due to molecular formations, and they reproduce in laboratory some astrophysical situations. C1 Ecole Polytech, CNRS, LULI, F-91128 Palaiseau, France. Univ Paris 06, F-75252 Paris 05, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Univ Jena, MPG Res Unit Xray Opt, D-6900 Jena, Germany. RP Angelo, P (reprint author), Ecole Polytech, CNRS, LULI, F-91128 Palaiseau, France. RI Sauvan, Patrick/M-3778-2014 OI Sauvan, Patrick/0000-0002-9128-8817 NR 13 TC 3 Z9 3 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PY 1998 VL 16 IS 1 BP 21 EP 30 PG 10 WC Physics, Applied SC Physics GA ZM099 UT WOS:000073504600005 ER PT J AU Johnson, DJ Rosenthal, SE Coats, RS Desjarlais, MP Lockner, TR Mehlhorn, T Pointon, TD Ruiz, CL Stygar, WA Slutz, SA Wenger, DF AF Johnson, DJ Rosenthal, SE Coats, RS Desjarlais, MP Lockner, TR Mehlhorn, T Pointon, TD Ruiz, CL Stygar, WA Slutz, SA Wenger, DF TI Lithium beam generation and focusing with a radial diode on PBFAII SO LASER AND PARTICLE BEAMS LA English DT Article; Proceedings Paper CT 24th European Conference on Laser Interaction with Matter (ECLIM 96) CY JUN 03-07, 1996 CL MADRID, SPAIN ID B ION DIODES; INERTIAL CONFINEMENT FUSION; IN-CELL SIMULATIONS; ELECTRON FLOW; DIVERGENCE; TW AB The performance of a 15-cm-radius applied-magnetic-fieId ion diode was investigated on the PBFA II accelerator at a power of 23 TW. The power coupling between the accelerator and diode was measured and compared with numerical simulations that show the effects of the electron flow in the MITL. The power coupled to the cathode of the diode was 18 MW. Measurements of the lithium beam generated from an electric-field-emission LiF anode showed a lithium beam power of 9 TW. The lithium beam was ballistically focused in a gas cell filled with 2 torr argon. The resultant focused power density was similar to 1.8 TW/cm(2) equivalent on a cylindrical target at the centerline of the diode. The focused power was limited by the 20- to 30-mR divergence of the beam caused by the LiF source used and by virtual cathode instabilities in the anode-cathode gap. The ion mode instability in the virtual cathode was studied extensively by measurement of waves in the ion emission pattern from the anode and of the E-P-theta correlation between variations in the beam energy and transverse momentum. The instability played a dominant role in the limitation of the focused lithium power. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Johnson, DJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 46 TC 10 Z9 10 U1 1 U2 3 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PY 1998 VL 16 IS 1 BP 185 EP 224 PG 40 WC Physics, Applied SC Physics GA ZM099 UT WOS:000073504600018 ER PT J AU Koch, JA Back, CA Brown, C Estabrook, K Hammel, BA Hatchett, SP Key, MH Kilkenny, JD Landen, OL Lee, RW Moody, JD Offenberger, AA Pennington, D Ferry, MD Tabak, M Yanovsky, V Wallace, RJ Wharton, KB Wilks, SC AF Koch, JA Back, CA Brown, C Estabrook, K Hammel, BA Hatchett, SP Key, MH Kilkenny, JD Landen, OL Lee, RW Moody, JD Offenberger, AA Pennington, D Ferry, MD Tabak, M Yanovsky, V Wallace, RJ Wharton, KB Wilks, SC TI Time-resolved X-ray spectroscopy of deeply buried tracer layers as a density and temperature diagnostic for the fast ignitor SO LASER AND PARTICLE BEAMS LA English DT Article; Proceedings Paper CT 24th European Conference on Laser Interaction with Matter (ECLIM 96) CY JUN 03-07, 1996 CL MADRID, SPAIN ID LASER-PRODUCED PLASMA; PULSES; AMPLIFICATION; COMPRESSION; GENERATION; RADIATION; TRANSPORT; MODEL AB The fast ignitor concept for inertial confinement fusion relies on the generation of hot electrons, produced by a short-pulse ultrahigh intensity laser, which propagate through high-density plasma to deposit their energy in the compressed fuel core and heat it to ignition. In preliminary experiments designed to investigate deep heating of high-density matter, we used a 20 joule, 0.5-30 ps laser to heat solid targets, and used emission spectroscopy to measure plasma temperatures and densities achieved at large depths (2-20 microns) away from the initial target surface. The targets consisted of an Al tracer layer buried within a massive CH slab; H-like and He-like line emission was then used to diagnose plasma conditions. We observe spectra from tracer layers buried up to 20 microns deep, measure emission durations of up to 200 ps, measure plasma temperatures up to T-e = 650 eV, and measure electron densities above 10(23) cm(-3). Analysis is in progress, but the data are in reasonable agreement with heating simulations when space-charge induced inhibition is included in hot-electron transport, and this supports the conclusion that the deep heating is initiated by hot electrons. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Koch, JA (reprint author), Lawrence Livermore Natl Lab, POB 808,L-473, Livermore, CA 94550 USA. RI Yanovsky, Victor/B-5899-2008 NR 31 TC 12 Z9 12 U1 0 U2 6 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PY 1998 VL 16 IS 1 BP 225 EP 232 PG 8 WC Physics, Applied SC Physics GA ZM099 UT WOS:000073504600019 ER PT J AU Humphries, S Ekdahl, C AF Humphries, S Ekdahl, C TI Finite-element simulation code for high-power magnetohydrodynamics SO LASER AND PARTICLE BEAMS LA English DT Article ID MODEL AB We describe the mathematical basis and organization of Crunch, a 1D shock-hydrodynamics code to analyze pulsed-power experiments at Los Alamos :National Laboratory. The program uses finite-element methods that preserve stability during material collisions and shock convergence on axis. It handles coupled calculations of nonlinear magnetic diffusion to simulate imploding liners. These calculations may be driven, by multiple current waveforms or a self-consistent current variation derived from a pulsed-power generator model. Crunch incorporates elastic material contributions and calculates element break and melt points. The primary goal in program development was effective use by experimentalists. Crunch is controlled by a streamlined script language and runs on standard personal computers. An interactive graphical postprocessor expedites analysis of results. To support the program we have assembled data resources in machine-independent format including Sesame equation-of-state tables, a material strength library and a library of temperature-dependent conductivities. C1 Field Precis, Albuquerque, NM 87192 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Humphries, S (reprint author), Field Precis, Albuquerque, NM 87192 USA. NR 29 TC 1 Z9 1 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PY 1998 VL 16 IS 3 BP 405 EP 430 PG 26 WC Physics, Applied SC Physics GA 130BF UT WOS:000076498800001 ER PT J AU Albrecht, GF Sutton, SB George, EV Sooy, WR Krupke, WF AF Albrecht, GF Sutton, SB George, EV Sooy, WR Krupke, WF TI Solid state heat capacity disk laser SO LASER AND PARTICLE BEAMS LA English DT Article; Proceedings Paper CT 28th Winter Colloquium on the Physics of Quantum Electronics CY JAN 04-07, 1998 CL SNOWBIRD, UTAH ID ND AB This paper describes a solid state laser concept that scales to MW levels of burst power and MJ of burst energy and burst durations measured in seconds. During lasing action, waste heat is purposely stored in the heat capacity of the active medium. The paper outlines the principal scaling laws of key operational features and arrives at a conceptual design example of the laser head as well as a mobile laser system. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Albrecht, GF (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-290, Livermore, CA 94550 USA. NR 28 TC 33 Z9 56 U1 3 U2 7 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PY 1998 VL 16 IS 4 BP 605 EP 625 PG 21 WC Physics, Applied SC Physics GA 151UM UT WOS:000077739100006 ER PT S AU Lippert, T AF Lippert, T BE Dubowski, JJ Dyer, PE TI Laser micromachining of chemically altered polymers SO LASER APPLICATIONS IN MICROELECTRONIC AND OPTOELECTRONIC MANUFACTURING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM III) at LASE 98 at Photonics West CY JAN 26-28, 1998 CL SAN JOSE, CA SP Int Soc Optical Engn DE photopolymer; laser ablation; mechanism; excimer laser; triazenopolymer AB During the last decade laser processing of polymers has become an important field of applied and fundamental research. One of the most promising proposal, to use laser ablation as dry etching technique in photolithography, has not yet become an industrial application. Many disadvantages of laser ablation, compared to conventional photolithography, are the result of the use of standard polymers. These polymers are designed for totally different applications, but are compared to the highly specialized photoresist. A new approach to laser polymer ablation will be described; the development of polymers, specially designed for high resolution laser ablation. These polymers have photolabile groups in the polymer backbone, which decompose upon laser irradiation or standard polymers are modified for ablation at a specific irradiation wavelength. The absorption maximum can be tailored for specific laser emission lines, e.g. 351, 308 and 248 nm lines of excimer lasers. We will show that with this approach many problems associated with the application of laser ablation for photolithography can be solved. The mechanism of ablation for these photopolymers is photochemical, whereas for most of the standard polymers this mechanism is photothermal. The photochemical decomposition mechanism results in high resolution ablation with no thermal damage at the edges of the etched structures. In addition there are no redeposited ablation products or surface modifications of the polymer after ablation. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lippert, T (reprint author), Univ Calif Los Alamos Natl Lab, CST 6,MS J 585, Los Alamos, NM 87545 USA. RI Lippert, Thomas/N-2423-2016 NR 0 TC 0 Z9 0 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2713-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3274 BP 204 EP 208 DI 10.1117/12.309513 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BL30Y UT WOS:000075053800023 ER PT S AU Feit, MD Rubenchik, AM Salleo, A Eimerl, D AF Feit, MD Rubenchik, AM Salleo, A Eimerl, D BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Pulseshape and pulselength scaling of Ns pulse laser damage threshold due to rate limiting by thermal conduction SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE laser damage; damage threshold; scaling; thermal conduction AB Assuming the observed scaling of laser damage threshold fluence with the (almost) square root of pulse duration is due to thermal conduction, we develop a formalism for directly comparing pulses of different shapes and durations. We find, for example, that a top hat pulse leads to 15% higher temperature (presumably 15% lower damage threshold) than a Gaussian pulse of the same fluence. We also find that the damage threshold of the expected NIF type pulse should be estimated from a Gaussian pulse with the same peak intensity. We find that the deviation of the scaling of damage threshold from square root of pulse duration has contributions from both the small but finite size of laser energy absorbers and from the temperature dependence of thermal properties. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Feit, MD (reprint author), Univ Calif Lawrence Livermore Natl Lab, Mail Stop L-439, Livermore, CA 94550 USA. RI Feit, Michael/A-4480-2009 NR 0 TC 0 Z9 0 U1 0 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 5 EP 10 DI 10.1117/12.306987 PG 6 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100003 ER PT S AU Runkel, M DeYoreo, J Sell, W Milam, D AF Runkel, M DeYoreo, J Sell, W Milam, D BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Laser conditioning study of KDP on the Optical Sciences Laser using large area beams SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE KDP; DKDP; KD*P; bulk laser damage; laser conditioning AB Considerable attention has been paid over the years to the problem of growing high purity KDP and KD*P to meet damage threshold requirements on succeeding generations of inertial confinement fusion lasers at LLNL. While damage thresholds for these materials have increased over time, the current National Ignition Facility (NIF) maximum fluence requirement (redline) for KD*P frequency triplers of 14.3 J/cm(2) at 351 nm, 3 ns has not been reached without laser (pre)conditioning. It is reasonable to assume that, despite the rapid increase in damage thresholds for rapidly grown crystals, a program of large scale conditioning of the 192 NIF triplers will be required. Small area ramp (R/1) tests on single sites indicate that KDP damage thresholds can be raised on average up to 1.5X the unconditioned values. Unpublished LLNL 3 omega raster conditioning studies on KDP, however, have not conclusively shown that off-line conditioning is feasible for KD*P. Consequently, investigating the feasibility of on-line conditioning of NIF triplers at 3 omega has become a high priority for the KDP damage group at LLNL. To investigate the feasibility of on-line conditioning we performed a series of experiments using the Optical Sciences Laser (OSL) on numerous samples of conventional and rapid growth KDP and KD*P. The experiment entailed exposing sites on each sample to a range of ramped shot (N/1) sequences starting at average fluences of similar to 2 J/cm(2) (in a 7 mm "top hat" beam @ 351 nm, 3 ns) up to peak fluences of approximately 13 J/cm(2). Test results indicated that the most effective conditioning procedure entailed a 7-8 shot ramp starting at 2 J/cm(2) and ending at 12-13 J/cm(2). The pinpoint onset fluence for the 8/1 tests was 1.4 times that of the unconditioned site. Damage evolution appears to be exponential as a function of increasing fluence. When damage occurs after conditioning however, pinpoint density evolution exhibits a greater slope than less conditioned sites. The overall reduction in the total pinpoint number can be as high as 300X. Despite laser conditioning, the pinpoint onset for the samples considered is below the NIF redline fluence of 14.3 J/cm(2). In addition, the exponential pinpoint evolution curves indicate that damage levels at NIF redline fluences will be on the order of 10(4) pinpoints/mm(3). This suggests that there will be significant damage in NIF triplers, however, substantial damage has not been observed in the large Beamlet tripler (conventionally grown KD*P) under similar exposure conditions. By applying the OSL damage evolution curves to model NIF THG output spatial profiles it is possible to show damage in NIF triplers will be slight, consisting of isolated clusters with a few pinpoints at high fluence portions of the beam. This prediction has been verified by scatter mapping the 37 cm Beamlet tripler crystal. These results will be discussed in a future memo. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Runkel, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-250, Livermore, CA 94550 USA. NR 0 TC 18 Z9 18 U1 0 U2 8 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 51 EP 63 DI 10.1117/12.307034 PG 13 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100010 ER PT S AU Ferris, KF Chick, LA Exarhos, GJ Risser, SM AF Ferris, KF Chick, LA Exarhos, GJ Risser, SM BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Microstructural size effects on the dielectric response of inhomogeneous media SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE microstructure; dielectric response; electric fields; size dependence AB The microstructure of dielectric films is an inherent characteristic of the fabrication process, and imposes distinctive behavior on the electric field distributions in these inhomogeneous media. In this paper, we examine the size dependent problem for cubic defects for an Al2O3 dielectric material. Using the LOCALF method to analyze the electric field response, we have developed models for Al2O3 dielectric films of varying microstructure size and volume fraction, and compare these results with conventional effective medium methods. Besides the dielectric susceptibility and volume fraction dependencies, the physical size of the heterogeneities creates localized regions of high field intensity. C1 Battelle Mem Inst, Pacific NW Labs, Mat & Chem Sci Ctr, Richland, WA 99352 USA. RP Ferris, KF (reprint author), Battelle Mem Inst, Pacific NW Labs, Mat & Chem Sci Ctr, POB 999, Richland, WA 99352 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 142 EP 148 DI 10.1117/12.307009 PG 7 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100021 ER PT S AU Genin, FY Sheehan, L Yoshiyama, J Dijon, J Garrec, P AF Genin, FY Sheehan, L Yoshiyama, J Dijon, J Garrec, P BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI A statistical study of UV laser-induced failure of fused silica SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE UV laser damage; damage morphology; damage probability; damage statistics; silica AB A study was performed to rank the influence of the parameters that can determine the resistance to laser-induced damage of polished synthetic fused silica at 355 nm. These parameters included the type of fused silica, the polishing process, the cleaning method, the sample thickness, and the sample diameter. The study involved both measurements of the statistics of laser-induced damage thresholds (LIDT) and characterization of the damage morphologies. The samples were irradiated at 20 degrees incidence angle with a 6.5-ns-pulse at 355 nm on an automated damage testing (ADT) system. The LIDT was measured on a minimum of 100 sites for each sample to gather sufficient statistical information and the damage morphology was characterized by Nomarksi optical microscopy and SEM. The statistical damage curves were very reproducible. The LIDT was most influenced by the polishing process. Surface micro-pits were found on the surface after irradiation with damaging fluences close to the LIDT. Their density varied from less than 0.1x10(-3) to 26x10(-3) mu m(-2) for the samples polished with the two different processes. The type of fused silica, the cleaning method, and the sample diameter seemed to have secondary effects on the LIDT. Bulk damage (not triggered by self-focusing) was occasionally noticed for thicker samples in areas with very high surface LIDT. Sample cleaning was found to play a role in reducing the number of low LIDT sites, thereby affecting the statistical behavior of the distribution tail, but did not significantly affect the average damage behavior. Finally, input surface (IS) damage occurred statistically less frequently and at higher fluences than output surface (OS) damage. Further work is discussed to understand if this effect is caused by electric field enhancement on the OS, or fundamental differences in crack propagation behavior between IS and OS. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Genin, FY (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 8 Z9 8 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 155 EP 163 DI 10.1117/12.306993 PG 9 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100023 ER PT S AU Runkel, M Yan, M De Yoreo, J Zaitseva, N AF Runkel, M Yan, M De Yoreo, J Zaitseva, N BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI The effect of impurities and stress on the damage distributions of rapidly grown KDP crystals SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE KDP; laser damage distributions; impurities; bulk laser damage AB Development of high damage threshold, 50 cm, rapidly grown KD*P frequency triplers for operation on the National Ignition Facility(NIF) in the 14 J/cm(2), 351 nm, 3 ns regime requires a thorough understanding of how the crystal growth parameters and technologies affect laser induced damage. Of particular importance is determining the effect of ionic impurities (e.g. Cr3+, Fe3+, Al3+) which may be introduced in widely varying concentrations via the starting salts. In addition, organic particulates (e.g. Lucite and Teflon) can contaminate the solution as leachants from growth platforms or via mechanical ablation. Mechanical stresses in the crystals may also play a strong role in the laser-induced damage distribution (LIDD), particularly in the case of large boules where hydrodynamic forces in the growth tank may be quite high. In order to investigate the effects of various impurities and stresses on laser damage we have developed a dedicated, automated damage test system with diagnostic capabilities specifically designed for measuring time resolved bulk damage onset ard evolution. The data obtained makes it possible to construct characteristic damage threshold distributions for each sample. Test results obtained for a variety of KDP samples grown from high purity starting salts and individually doped with Lucite and Teflon, iron, chromium and aluminum show that the LIDD drops with increasing contamination content. The results also show that solution filtration leads to increased damage performance for undoped crystals but is not solely responsible for producing the high LIDDs required by the NIF. The highest LIDD measured on a rapidly grown sample indicate that it is possible to produce high damage threshold material using ultrahigh purity, recrystallized starting salts, continuous filtration and a platform designed to minimize internal stress during growth. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Runkel, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-250, Livermore, CA 94550 USA. NR 0 TC 9 Z9 9 U1 2 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 211 EP 222 DI 10.1117/12.307046 PG 12 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100029 ER PT S AU Demos, SG Yan, M Staggs, M Woods, BW Wu, ZL Radousky, HB De Yoreo, JJ AF Demos, SG Yan, M Staggs, M Woods, BW Wu, ZL Radousky, HB De Yoreo, JJ BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Temperature and spectral investigation of bulk KDP below damage using 355 nm laser irradiation SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE KDP; Raman scattering; photothermal deflection; damage AB A spectral and temperature investigation of fast-grown KDP crystals under high fluence, 355 nm laser irradiation is discussed. Pump-and-probe Raman spectroscopy indicate transient changes of the vibrational spectrum. Photothermal deflection experiments provide information on the temporal behavior of the temperature change. The presence of emission in the visible and NIR spectral regions is attributed to the presence of impurities and/or defects in the crystal. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94580 USA. RP Demos, SG (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94580 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 223 EP 227 DI 10.1117/12.307029 PG 5 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100030 ER PT S AU Woods, B Yan, M De Yoreo, J Kozlowski, M Radousky, H Wu, Z AF Woods, B Yan, M De Yoreo, J Kozlowski, M Radousky, H Wu, Z BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Photothermal mapping of defects in the study of bulk damage in KDP SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE KDP; DKDP; bulk damage; photothermal deflection AB Interest in producing high-damage-threshold KH2PO4 (KDP) and (DxH1-x)(2)PO4 (DKDP) (also called KD*P) for frequency conversion and optical switching applications is driven by the requirements of the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL).(1) At present only the best crystals meet the NIF system requirements at the third harmonic (351nm) and only after a laser conditioning process. Neither the mechanism for damage in bulk KDP nor the mechanism for conditioning is understood. As part of a development effort to increase the damage thresholds of KDP and DKDP, we have been developing techniques to pinpoint the locations where damage will initiate in the bulk material. After successfully developing a diagnostic tool that will find these locations, we will use other measurement techniques to determine how these locations differ from the surrounding material and why they cause damage. This will allow crystal growers to focus their efforts during the growth process in improving damage thresholds. Previously we reported that there was a low correlation between defects in crystals located using light scatter and the sites where damage would initiate.(2) Damage, when it occurs, is almost certainly associated with a localized heating of the crystal which results in mechanical damage to or chemical decomposition of the crystal lattice. If this heating occurs at fluences below the damage threshold, we should be able to measure this heating and predict the locations where damage will initiate prior to damaging the crystal. As a result, we are developing photothermal (PT) techniques to probe the bulk material to look for heating due to localized absorption and to determine the correlation between localized heating and the initiation sites for damage. This paper reviews the current status of our photothermal work on KDP. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Woods, B (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 4 Z9 4 U1 1 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 242 EP 248 DI 10.1117/12.307033 PG 7 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100032 ER PT S AU Yan, M Wang, L Siekhaus, W Kozlowski, M Yang, J Mohideen, U AF Yan, M Wang, L Siekhaus, W Kozlowski, M Yang, J Mohideen, U BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Defect study in fused silica using near field scanning optical microscopy SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE near field scanning optical microscopy; defects; nano-indentation; fused silica AB Surface defects in fused silica have been characterized using Near Field Scanning Optical Microscopy (NSOM). Using total internal reflection of a p- or s- polarized laser beam, optical scattering from defects located on the surface itself as well as in the subsurface layer of polished fused silica has been measured by NSOM. The local scattering intensity has been compared with simultaneously measured surface topography, In addition, surface defects intentionally created on a fused silica surface by nano-indentation have been used to establish a correlation between optical scattering of s- and p- polarized light, surface morphology and the well known subsurface stress-field associated with nano-indentation. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Yan, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-250, Livermore, CA 94551 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 268 EP 271 DI 10.1117/12.307032 PG 4 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100035 ER PT S AU Rainer, F AF Rainer, F BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Mapping and inspection of damage and artifacts in large-scale optics SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE damage; damage mapping; laser-induced damage; optics AB We have developed tools and procedures for accurately and economically mapping and inspecting damage and artifacts in the bulk as well as on the surfaces of meter-sized optics intended for use on large-scale lasers such as Beamlet and NIF. Optics are illuminated by white light through the optic edge or externally at grazing incidence using linear fiber-optic arrays. A mega-pixel camera records a digital map of the entire op tic with precise addresses of highlighted artifacts. From these coordinates, artifacts are located and digitally recorded with resolutions of less than 5 mu m using a long-working-distance microscope. Total internal reflection of edge illumination efficiently couples light into the entire optic to inspect for bulk artifacts such as bubbles, inclusions, edge-cladding flaws and laser-induced damage as well as surface scratches and pits which propagate into the substrate. Surface contamination such as dust, fingerprints, coating flaws and cleaning flaws are highlighted by external grazing illumination. The procedures permit accurate recording of the evolution of damage after many laser shots as well as correlation of damage from one optic to the next in a laser chain. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Rainer, F (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 5508,L-487, Livermore, CA 94551 USA. NR 0 TC 4 Z9 4 U1 4 U2 10 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 272 EP 281 DI 10.1117/12.307019 PG 10 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100036 ER PT S AU Sheehan, LM Kozlowski, M Camp, DW AF Sheehan, LM Kozlowski, M Camp, DW BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Application of Total Internal Reflection Microscopy for laser damage studies on fused silica SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE Total Internal Reflection Microscopy; Atomic Force Microscopy; fused silica; localized scatter; laser induced damage AB Damage studies show that the majority of damage on ultraviolet grade fused silica initiates at the front or rear surface. The grinding and polishing processes used to produce the optical surfaces of transparent optics play a key role in the development of defects which can ultimately initiate damage. These defects can be an or breaking through the surface or can be sub-surface damage. Total Internal Reflection Microscopy has been documented as a tool for revealing both sub-surface and surface defects in transparent materials. Images taken which compare both Total Internal Reflection Microscopy and Atomic Force Microscopy show that the observed defects can be less than one micron in size. Total Internal Reflection Microscopy has the added benefit of being able to observe large areas (1 square millimeter) with sub-micron detection, Both off-line and in-situ systems have been applied in the Lawrence Livermore National Laboratory's damage laboratory in order to understand defects in the surface and subsurface of polished fused silica, There is a preliminary indication that TIRM quality can be related to the damage resistance. The in-situ microscope is coupled into a 355 nm, 7.5 ns, 10 Hz Nd:YAG laser system in order to study damage occurring at localized scatter sites revealed with the Total Infernal Reflection Microscopy method. The tests indicate damage initiating at observed artifacts which have many different morphologies and damage behaviors. Some of the scatter sites and damage morphologies revealed have been related back to the finishing process. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Sheehan, LM (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-496, Livermore, CA 94550 USA. NR 0 TC 22 Z9 22 U1 0 U2 6 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 282 EP 295 DI 10.1117/12.307030 PG 14 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100037 ER PT S AU Yoshiyama, J Genin, FY Salleo, A Thomas, I Kozlowski, MR Sheehan, LM Hutcheon, ID Camp, DW AF Yoshiyama, J Genin, FY Salleo, A Thomas, I Kozlowski, MR Sheehan, LM Hutcheon, ID Camp, DW BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI A study of the effects of polishing, etching, cleaving, and water leaching on the UV laser damage of fused silica SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE laser-induced damage threshold; fused silica; 355 nm; damage morphology; sub-surface damage; microcracks; etching; surface contamination; environmental effects AB A damage morphology study was performed with a 355 nm, 8-ns Nd:YAG laser on synthetic UV-grade fused silica to determine the effects of post-polish chemical etching on laser-induced damage, compare damage morphologies of cleaved and polished surfaces, and understand the effects of the hydrolyzed surface layer and water-crack interactions. The samples were polished, then chemically etched in a buffered HF solution to remove 45, 90, 135, and 180 nm of surface material. Another set of samples was cleaved and soaked in boiling distilled water for 1 second and 1 hour. All the samples were irradiated at damaging fluences and characterized by Normarski optical microscopy and scanning electron microscopy. Damage was initiated at micro-pits (smaller than 1 mu m in diameter) on both input and output surface of the polished fused silica sample. At higher fluences, the micro-pits generated cracks on the surface. Laser damage of the etched fused silica surface showed that the areal density of micro-pits decreased with etched thickness. SIMS analysis of the polished surface showed significant trace contamination levels within a 50 nm surface layer. Micro-pits formation also appeared after irradiating cleaved fused silica surfaces at damaging fluences. Linear damage tracks corresponding cleaving cracks were often observed on cleaved surfaces. Soaking cleaved samples in water produced wide laser damage tracks. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Yoshiyama, J (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 19 Z9 19 U1 1 U2 13 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 331 EP 340 DI 10.1117/12.307041 PG 10 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100043 ER PT S AU Salleo, A Genin, FY Yoshiyama, J Stolz, CJ Kozlowski, MR AF Salleo, A Genin, FY Yoshiyama, J Stolz, CJ Kozlowski, MR BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Laser-induced damage of fused silica at 355 nm initiated at scratches SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE laser-induced damage threshold; 355 nm; fused silica; scratches; cracks; light intensification AB Scratches of measured width were produced on the surface of a W grade fused silica window using a diamond tip. Two scratch morphologies were observed: plastic and brittle. The scratches were irradiated with a 355 nm laser pulse. The laser-induced damage threshold (LIDT) of the unscratched output surface was 15 J/cm(2) at 3-ns. The LIDT of the scratched surface as a function of scratch width was then measured for both input and output surface scratches. Input surface scratches of width smaller than 10 mu m did not influence the LIDT of the silica window. On the output surface, 7 mu m wide scratches lowered the LIDT by a factor of two. For larger scratches, the LIDT reached an asymptotic value of 5 J/cm(2) on both input and output surface. Possible reasons for this LIDT drop could be electric field enhancement in the cracks below the scratch, the presence of contamination particles in the scratch, or the weakening of the material because of existing mechanical flaws. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Salleo, A (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 26 Z9 27 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 341 EP 347 DI 10.1117/12.307039 PG 7 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100044 ER PT S AU Genin, FY Campbell, J Yoshiyama, J Salleo, A Sands, T AF Genin, FY Campbell, J Yoshiyama, J Salleo, A Sands, T BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Quantitative damage morphology analysis of laser-induced surface cracks in fused silica at 355 nm SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE laser-induced damage; crack; surface morphology; fused silica; 355 nm AB A morphology study was conducted on fused silica surfaces damaged by single pulse laser irradiation at 355 nm. The physical characterization of the surface showed that cracks initiate at ellipsoidal pits (less than 1 mu m in size) on both input and output surfaces. The size of the pit increases with laser pulse-length and the orientation of the ellipse is perpendicular to the electric field. The pits are less than 300 nm deep. Cracks initiate along the main axis of the ellipse. The morphology of the cracks is different for input vs, output surfaces. The output surface crack exhibits a shell-like morphology typical of localized compressive stress. The input surface crack shows, on the other hand, a star-like pattern. These differences seem to be caused by differences in plasma propagation on the surface. The extent of damage and the number of shells (output) or branches (input) increases with increasing fluence. a molten morphology can be observed at the center of the cracks for fluences above the pit formation threshold. This indicates that local temperatures can be in excess of several thousand degrees Centigrade. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Genin, FY (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Sands, Timothy/D-2133-2009 OI Sands, Timothy/0000-0001-9718-6515 NR 0 TC 1 Z9 1 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 348 EP 349 DI 10.1117/12.307036 PG 2 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100045 ER PT S AU Feit, MD Campbell, J Faux, D Genin, FY Kozlowski, MR Rubenchik, AM Riddle, R Salleo, A Yoshiyama, J AF Feit, MD Campbell, J Faux, D Genin, FY Kozlowski, MR Rubenchik, AM Riddle, R Salleo, A Yoshiyama, J BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Modeling of laser-induced surface cracks in silica at 355-nm SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE nanoparticles; laser absorption; heating; brittle fracture AB Starting from the absorption of laser energy at a subsurface nanoparticle in fused silica, we simulate the consequent buildup of stresses and resulting mechanical material damage. The simulation indicates the formation of micropits with size comparable to a wavelength, similar to experimental observation. Possible mechanisms for enhanced local light absorbtion are discussed. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Feit, MD (reprint author), Univ Calif Lawrence Livermore Natl Lab, Mail Stop L-439, Livermore, CA 94550 USA. RI Feit, Michael/A-4480-2009 NR 0 TC 30 Z9 31 U1 0 U2 8 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 350 EP 355 DI 10.1117/12.307035 PG 6 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100046 ER PT S AU Camp, DW Kozlowski, MR Sheehan, LM Nichols, M Dovik, M Raether, R Thomas, I AF Camp, DW Kozlowski, MR Sheehan, LM Nichols, M Dovik, M Raether, R Thomas, I BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Subsurface damage and polishing compound affect the 355-nm laser damage threshold of fused silica surfaces SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE laser damage; ultraviolet; 3-omega; fused silica; polishing; grinding; subsurface damage; ceria; zirconia; optics AB Subsurface damage (SSD), namely grinding and polishing fractures or scratches hidden by the polishing redeposition layer, may lower laser damage threshold by reducing fracture strength, providing sites for absorbing; contaminants, and modulating the electromagnetic field. Polishing compound may affect 355-nm laser damage by absorption and scratching. Fused silica surfaces were finished with different grinding and polishing removal depths to leave different extents of subsurface damage from grinding. Three surfaces were polished with ceria and three with zirconia. The surfaces were 355-nm laser damage tested using an automated "R-on-1" protocol, and also characterized for surface roughness, subsurface damage as revealed by etching, and Total Internal Reflectance Microscopy (TIRM). The zirconia polishing produced the highest laser thresholds, especially when the surface was free of polishing and grinding damage. The zirconia polishing was prone to damaging the surface, which significantly reduced laser thresholds at some sites. The ceria polishing let very little polishing damage, and showed uniform damage thresholds when there was no subsurface damage from grinding present. Residual Blanchard fractures lowered thresholds dramatically. Subsurface fractures from fine loose grinding sometimes reduced thresholds dramatically and sometimes very little. TIRM images correlate fairly well with microphotographs of subsurface damage revealed by etching. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94605 USA. RP Camp, DW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94605 USA. NR 0 TC 83 Z9 88 U1 1 U2 22 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 356 EP 364 DI 10.1117/12.307044 PG 9 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100047 ER PT S AU Kozlowski, MR Carr, J Hutcheon, I Torres, R Sheehan, L Camp, D Yan, M AF Kozlowski, MR Carr, J Hutcheon, I Torres, R Sheehan, L Camp, D Yan, M BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Depth profiling of polishing-induced contamination on fused silica surfaces SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE CeO2; contaminants; fused silica; polishing; surface; 355 nm AB Laser-induced damage on optical surfaces is often associated with absorbing contaminants introduced by the polishing process. This is particularly the case for W optics. In the present study, secondary ion mass spectroscopy (SIMS) was used to measure depth profiles of finishing-process contamination on fused silica surfaces. Contaminants detected include the major polishing compound components (Ce or Zr from CeO2 or ZrO2), Al present largely because of the use of Al2O3 in the final cleaning process, and other metals (Fe, Cu, Cr) incorporated during the polishing step or earlier grinding steps. Depth profile data typically showed an exponential decay of contaminant concentration to a depth of 100-200 nm. This depth is consistent with a polishing redeposition layers formed during the chemo-mechanical polishing of fused silica. Peak contaminant levels are typically in the 10-100 ppm range, except for Al which often exceeds 1000 ppm. A strong correlation has been shown between the presence of a "gray haze" damage morphology and the use of CeO2 polishing compound. It has not been proven, however, that linear absorption by CeO2, or any other contaminant, is the relevant damage mechanism. Simple thermomechanical calculations show that for the contaminant levels present, temperatures high enough to cause damage are only likely if the contaminant was present as particles with diameters of 10-30 nm. We are not able to prove or disprove the presence of such particles. No strong correlation between high levels of Ce, or any other contaminant, and low damage threshold is observed. In fact one of the strongest indications of a correlation is between increased damage thresholds and increased Zr contamination. This suggests that the connection between redeposition layer contamination and laser damage threshold is not simply an absorbing contaminant issue. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Kozlowski, MR (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 37 Z9 37 U1 0 U2 12 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 365 EP 375 DI 10.1117/12.307031 PG 11 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100048 ER PT S AU Chow, R Taylor, JR Wu, ZL Han, Y Yang, TL AF Chow, R Taylor, JR Wu, ZL Han, Y Yang, TL BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Absorptance measurements of transmissive optical components by the surface thermal lensing technique SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE absorptance; anti-reflector; beam splitter; laser optics; surface thermal lensing; photothermal AB The surface thermal lensing technique (STL) successfully reserved and measured the absorptance of transmissive optical components: near-normal angle-of-incidence anti-reflectors and beam splitters. The STL system uses an Ar ion laser to pump the components at 514.5 nm. The absorptance-induced surface deformation diffracts the HeNe probe beam into a photo-detector. The signal intensity was calibrated with a sample of known absorptance. The optical components were designed to function in a copper vapor laser (CVL) transport system, and were previously tested for absorptance with a high power CVL system at 511 nm. To assure proper absorptance data from the STL system, the pump laser power densities were set at the operational lever of the coatings, absorptance time trends were monitored, and absorptance area scans were made. Both types of transmissive optics are more stable than the CVL high reflectors that were measured in another study. Parameter studies based on Fresnel diffraction theory were also performed to optimize experimental condition. The STL system was assessed to have 10 ppb sensitivity for absorption measurement given 2 W of pump power. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Chow, R (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 0 TC 4 Z9 5 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 376 EP 385 DI 10.1117/12.306992 PG 10 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100049 ER PT S AU Setchell, RE AF Setchell, RE BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI End-face preparation methods for high-intensity fiber applications SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE fiber optics; fiber damage; cleaved fibers; flame polishing; CO2-laser conditioning; diffractive optics AB High laser intensities are being transmitted through optical fibers in a growing number of applications. Our interest in laser initiation of explosives has led us to examine the transmission of Q-switched, Nd:YAG laser pulses through step-index, multimode, fused-silica fibers for a number of years. A common limiting process is a plasma-forming breakdown occurring at the fiber entrance face. The breakdown threshold at this face depends on the surface characteristics that result from tile particular method of end-face preparation. In previous studies ale examined entrance-face breakdown thresholds for several different mechanical polishing schedules, and also for several schedules of CO2-laser conditioning following mechanical polishing. In the present study we examined three end-face preparation methods that were based on the recent availability of exceptionally good cleaved surfaces for our fibers of interest. Using test procedures similar to those in past studies, we examined the cleaved fibers directly, fibers with cleaved surfaces that were subsequently flame polished, and fibers with cleaved surfaces that were subsequently conditioned with a CO2 laser. All of these preparation methods resulted in fibers that showed a broader range of entrance-face breakdown conditions than found in past studies, together with a susceptibility to subsurface exit-face damage. By introducing additional cleaning steps with the cleaved surfaces, we were able to reduce the variability in breakdown thresholds observed after subsequent CO2-laser conditioning. A consistent location of exit-face damage sites indicates that subsurface fracturing occurs during tile cleaving process, and that the subsequent end-face processing steps were not effective in mitigating damage at these sites. Threshold energies for entrance-face breakdown are also affected by the relation between incident laser energy and the resulting peak local Fluence at this surface. Laser characteristics and the design of the laser-to-fiber injection optics determine this relation. The present study utilized an Improved injection system consisting of a custom diffractive optical element combined with a lens having a very short focal length. This system produced the lowest value for the ratio of peak-to-average fluence at the entrance face that ive have observed, and was very successful in inhibiting internal damage mechanisms along the fiber path. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Setchell, RE (reprint author), Sandia Natl Labs, MS1421, Albuquerque, NM 87185 USA. NR 0 TC 10 Z9 10 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 390 EP 399 DI 10.1117/12.306994 PG 10 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100051 ER PT S AU Exarhos, GJ Rose, A Schielke, KP AF Exarhos, GJ Rose, A Schielke, KP BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Pulsed laser irradiation of isothermally heated titania films SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE microstructure; Raman spectroscopy; sol-gel; stress; temperature AB Stoichiometric titanium dioxide films comprised of either amorphous or anatase phases have been deposited onto cleaned silica substrates by means of a low pH sol-gel processing method. Coated optics were then exposed to pulsed 1064 nm light-from a Nd:YAG laser. irradiations were performed on samples heated in an oven held at temperatures between 300 and 450 K. A marked decrease in the threshold for catastrophic damage was observed at increased film temperature for both Q-switched and non-Q-switched pulses which is likely due to a thermally induced increase in film residual stress. However, continued irradiation of damaged regions with non-Q-switched pulses at slightly higher temperatures was found to heal the damaged regions. Subsequent irradiation at somewhat higher temperatures generated additional damage sites which could not be healed upon additional irradiation at still higher temperatures. Films were characterized by means of optical transmission measurements, Raman spectroscopy, and optical microscopy. Results demonstrate the influence of ambient film temperature on irradiation damage phenomena. C1 Battelle Mem Inst, Pacific NW Labs, Richland, WA 99352 USA. RP Exarhos, GJ (reprint author), Battelle Mem Inst, Pacific NW Labs, POB 999, Richland, WA 99352 USA. NR 0 TC 1 Z9 1 U1 0 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 458 EP 468 DI 10.1117/12.307004 PG 11 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100058 ER PT S AU Stolz, CJ Yoshiyama, JM Salleo, A Wu, ZL Green, J Krupka, R AF Stolz, CJ Yoshiyama, JM Salleo, A Wu, ZL Green, J Krupka, R BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Characterization of nodular and thermal defects in hafnia/silica multilayer coatings using optical, photothermal, and atomic force microscopy SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE laser-induced damage; hafnia-silica multilayer coating; laser damage morphology; coating defects; optical microscopy; atomic force microscopy; photothermal microscopy AB Multilayer coatings manufactured from metallic hafnium and silica sources by reactive electron beam deposition, are being developed for high fluence optics in a fusion laser with a wavelength of 1053 nm and a 3 ns pulse length. Damage threshold studies have revealed a correlation between laser damage and nodular defects, but interestingly laser damage is also present in nodule-free regions. Photothermal studies of optical coatings reveal the existence of defects with strong optical absorption in nodule-free regions of the coating. A variety of microscopic techniques were employed to characterize the defects for a better understanding of the thermal properties of nodular defects and role of thermal defects in laser damage. Photothermal microscopy, utilizing the surface thermal lensing technique, was used to map the thermal characteristics of 3 mm x 3 mm areas of the coatings. High resolution subaperture scans, with a 1 mu m step size and a 3 mu m pump beam diameter, were conducted on the defects to characterize their photothermal properties. Optical and atomic force microscopy was used to visually identify defects and characterize their topography. The defects were then irradiated to determine the role of nodular and thermal defects in limiting the damage threshold of the multilayer. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Stolz, CJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-487, Livermore, CA 94550 USA. NR 0 TC 11 Z9 11 U1 0 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 475 EP 483 DI 10.1117/12.307008 PG 9 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100060 ER PT S AU Whitman, P Milam, D Norton, M Sell, W AF Whitman, P Milam, D Norton, M Sell, W BE Exarhos, GJ Guenther, AH Kozlowski, MR Soileau, MJ TI Loss of transmittance in fluoropolymer films due to laser-induced damage at 1053 and 351 nm SO LASER-INDUCED DAMAGE IN OPTICAL MATERIALS: 1997, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 29th Annual Boulder Damage Symposium on Laser-Induced Damage in Optical Materials - 1997 CY OCT 06-08, 1997 CL BOULDER, CO SP Lawrence Livermore Natl Lab, Univ New Mexico, Ctr High Technol Mat, Univ Cent Florida, Ctr Res & Educ Opt & Lasers, Def Res Agcy, UK, Natl Inst Stand & Technol, Pacific NW Natl Lab, Soc Photo Opt Instrumentat Engineers DE fluoropolymer; FEP; laser damage; inertial confinement fusion AB Thick fluoropolymer films are being evaluated as a potential 'disposable' debris shield to protect high-peak-power laser optics from x-ray and target debris generated in inertial-confinement fusion-ignition experiments. Two obstacles to implementation are optical uniformity and damage threshold. To understand the damage characteristics, transmittance of single 1053- or 351-nm laser pulses has been measured for commercial fIuoropolymer films in vacuum. Samples were tested at fluences up to 105 J/cm2 at 1053-nm and 13 J/cm2 at 351-nm. Both the total transmitted energy for a single shot and the temporal energy transmittance profile during the shot were measured as a function of fluence, In addition, the total focusable transmitted energy was recorded for 351-nm pulses. Results show that transmittance decreases slowly during a single-pulse irradiation, allowing much of the energy to be transmitted at fluences which cause noticeable degradation to the film. The film transmits greater than 90% of the 351-nm energy delivered in a beam with spatial average fluence of g J/cm2 with modulation up to 15 J/cm2. For 1053-nm laser light, the films do not begin to exhibit noticeable transmittance loss until average fluences exceed 40 J/cm2. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Whitman, P (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 5508,L-487, Livermore, CA 94551 USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2683-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3244 BP 528 EP 534 DI 10.1117/12.306998 PG 7 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BL09Y UT WOS:000074259100068 ER PT J AU Kotseroglou, T Bamber, C Berridge, SC Boege, SJ Bugg, WM Bulal, C Burke, DL Field, RC Horton-Smith, G Koffas, T McDonald, KT Melissinos, AC Meyerhofer, DD Prebys, EJ Ragg, W Reis, DA Shmakov, K Spencer, JE Walz, D Weidemann, AW AF Kotseroglou, T Bamber, C Berridge, SC Boege, SJ Bugg, WM Bulal, C Burke, DL Field, RC Horton-Smith, G Koffas, T McDonald, KT Melissinos, AC Meyerhofer, DD Prebys, EJ Ragg, W Reis, DA Shmakov, K Spencer, JE Walz, D Weidemann, AW CA E-144 Collaboration TI Studies of nonlinear QED in high energy electron-laser collisions SO LASER PHYSICS LA English DT Article AB We discuss results obtained at the Stanford Linear Accelerator Center in the interaction of 46.6 GeV electrons crossing through the focus of a terawatt laser at lambda = 527 nm. Under those circumstances the field seen in the electron rest frame approaches the critical field of QED. Multiphoton Compton scattering with the absorption of as many as 4 photons from the laser field as well as e(+)e(-)pair production in the collision of a high energy gamma with several laser photons were observed. This is the first evidence for strong QED interactions and the data agree with the theoretical predictions. Furthermore this is the first observation of inelastic light-by-light scattering involving only real photons. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Princeton Univ, Joseph Henry Labs, Princeton, NJ 08544 USA. Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. Univ Rochester, Dept Mech Engn, Rochester, NY 14627 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Kotseroglou, T (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RI Horton-Smith, Glenn/A-4409-2011 OI Horton-Smith, Glenn/0000-0001-9677-9167 NR 16 TC 0 Z9 0 U1 0 U2 3 PU INTERPERIODICA PI BIRMINGHAM PA PO BOX 1831, BIRMINGHAM, AL 35201-1831 USA SN 1054-660X J9 LASER PHYS JI Laser Phys. PD JAN-FEB PY 1998 VL 8 IS 1 BP 142 EP 149 PG 8 WC Optics; Physics, Applied SC Optics; Physics GA ZB459 UT WOS:000072474100022 ER PT S AU Sackos, JT Nellums, RO Lebien, SM Diegert, CF Grantham, JW Monson, T AF Sackos, JT Nellums, RO Lebien, SM Diegert, CF Grantham, JW Monson, T BE Kamerman, GW TI A low-cost, high-resolution, video-rate imaging optical radar SO LASER RADAR TECHNOLOGY AND APPLICATIONS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Laser Radar Technology and Applications III CY APR 14-16, 1998 CL ORLANDO, FL SP SPIE DE laser radar; LADAR; imaging optical radar AB Sandia National Laboratories has developed a unique type of portable low-cost range imaging optical radar (laser radar or LADAR). This innovative sensor is comprised of an active floodlight scene illuminator and an image intensified CCD camera receiver. It is a solid-state device (no moving parts) that offers significant size, performance, reliability, and simplicity advantages over other types of 3-D imaging sensors. This unique flash LADAR is based on low cost, commercially available hardware, and is well suited for many government and commercial uses. This paper presents an update of Sandia's development of the Scannerless Range Imager technology and applications, and discusses the progress that has been made in evolving the sensor into a compact, low, cost, high-resolution, video rate Laser Dynamic Range Imager. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sackos, JT (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. OI Monson, Todd/0000-0002-9782-7084 NR 0 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2829-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3380 BP 327 EP 342 DI 10.1117/12.327205 PG 16 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BL68V UT WOS:000076320100034 ER PT S AU Martinez, MD Crane, J Hackel, L Penko, F Browning, D AF Martinez, MD Crane, J Hackel, L Penko, F Browning, D BE Kudryashov, AV Galarneau, P TI Optimized, diode pumped, Nd : glass, prototype regenerative amplifier for the National Ignition Facility (NIF) SO LASER RESONATORS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Resonators CY JAN 26-27, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE regenerative amplifier; National Ignition Facility (NIF); diode pumped AB The National Ignition Facility (NIF) will house a 2 UT Nd:glass laser system to be used for a broad range of inertial confinement fusion experiments. This record high energy laser output will be initiated by a single low energy, fiber-based master oscillator which will be appropriately shaped in time and frequency prior to being split into 48 beams for intermediate amplification These 48 intermediate energy beams will feed the 192 main amplifier chains. We report on the baseline design and test results for an amplifier subsystem in the intermediate amplifiers. The subsystem is based on a diode pumped, Nd:glass regenerative amplifier. The amplifier is comprised of a linear, folded, TEM00 4.5m long cavity and represents the highest gain (approximately 10(7)) component in the NIF laser system((1)) Two fundamentally important requirements for this amplifier include output energy of 20 mi with a square pulse distortion of less than 1.45. With a single 48 bar 4.5kW peak power diode array and lens duct assembly((2)), we pump a 5 mm diameter x 50 mn long Nd-doped, phosphate glass rod, and amplify the mode-matched, temporally shaped (approximately 20ns in duration)oscillator seed pulse to 25 mJ of output energy with a very acceptable square pulse distortion of 1.44. This most recent design of the regenerative amplifier has increased the performance and reduced the cost, enabling it to become a solid baseline design for the NIF laser system. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Martinez, MD (reprint author), Univ Calif Lawrence Livermore Natl Lab, 2000 E Ave,MS L-483, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2706-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3267 BP 234 EP 242 DI 10.1117/12.308111 PG 9 WC Optics SC Optics GA BL12U UT WOS:000074379500024 ER PT S AU Ha, T Ting, A Liang, J Glass, J Chemla, D Schultz, P Weiss, S AF Ha, T Ting, A Liang, J Glass, J Chemla, D Schultz, P Weiss, S BE Scherer, NF Hicks, JM TI Fluorescence spectroscopy of single molecule dynamics and its biological applications SO LASER TECHNIQUES FOR CONDENSED-PHASE AND BIOLOGICAL SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Techniques for Condensed-Phase and Biological Systems CY JAN 29-31, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Ha, T (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. OI weiss, shimon/0000-0002-0720-5426 NR 0 TC 2 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2712-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3273 BP 179 EP 185 DI 10.1117/12.306136 PG 7 WC Optics SC Optics GA BL12Y UT WOS:000074381300018 ER PT S AU Novotny, L Sanchez, EJ Xie, XS AF Novotny, L Sanchez, EJ Xie, XS BE Scherer, NF Hicks, JM TI Optical microscopy and spectroscopy beyond the diffraction limit SO LASER TECHNIQUES FOR CONDENSED-PHASE AND BIOLOGICAL SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Techniques for Condensed-Phase and Biological Systems CY JAN 29-31, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE near-field optics; microscopy; spectroscopy; nanotechnology; trapping AB A new approach to near-field optical microscopy is presented. The method relies on the highly enhanced fields at sharp metal tips under proper laser illumination. These fields are laterally confined to the tip size and can be used to locally excite the sample surface. Detection of nonlinear responses (two-photon fluorescence, generation of second/third harmonics) ensure sufficient background discrimination. The strong field gradients close to the tip give also rise to a trapping force towards the tip. Therefore, the proposed scheme is also promising for optical trapping and alignment of dielectric particles in aqueous environments at the nanometer scale. The paper presents the results of self-consistent three-dimensional field calculations. Starting with a discussion of commonly used aperture probes, the field distributions for the never scheme are presented. C1 Battelle Mem Inst, Pacific NW Labs, Richland, WA 99352 USA. RP Novotny, L (reprint author), Battelle Mem Inst, Pacific NW Labs, POB 999, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2712-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3273 BP 194 EP 202 DI 10.1117/12.306128 PG 9 WC Optics SC Optics GA BL12Y UT WOS:000074381300020 ER PT S AU Arnett, DC Kumble, R Visschers, RW Moser, CC Dutton, PL Hochstrasser, RM Scherer, NF AF Arnett, DC Kumble, R Visschers, RW Moser, CC Dutton, PL Hochstrasser, RM Scherer, NF BE Scherer, NF Hicks, JM TI Ultrafast studies of exciton dynamics in light harvesting dimers SO LASER TECHNIQUES FOR CONDENSED-PHASE AND BIOLOGICAL SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Techniques for Condensed-Phase and Biological Systems CY JAN 29-31, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE photosynthesis; femtosecond; anisotropy; exciton; B820; photosynthetic reaction center; Rs rubrum; Rb sphaeroides AB The electronic characteristics and rapid dynamics associated with bacteriochlorophyll dimers in photosynthetic systems are investigated using novel ultrafast anisotropy techniques. The excitonic structure of isolated dimeric subunits (B820) from the core (LH-1) light harvesting complex of Rs. Rubrum and the reassociated complex (B873) is revealed in coherent anisotropy responses following impulsive excitation. For B820, the oscillatory anisotropy responses indicate excitonic splitting frequencies ranging from 370 cm(-1) to 490 cm(-1) indicating significant inhomogeneity in the excitonic spectrum. The complete set of wavelength dependent anisotropy results is analyzed to reveal the sources of inhomogeneity for B820; correlated distributions of dimer energetic parameters are necessary to reproduce the results. The coherent responses of reassociated B873 complexes exhibit multiple frequencies, revealing the extended excitonic structure of the aggregates. In other experiments, the electronic properties of the photosynthetic reaction center and the rapid electronic dynamics prior to charge separation are investigated by both "two color" anisotropy and coherent anisotropy. A variety of excitation and detection conditions provide the first room temperature characterization of the excitonic structure of the special pair, and a detailed description of rapid energy transfer to and within the special pair. The results presented here stress the importance of delocalized excitation in both the light harvesting antenna complexes and the photosynthetic reaction center. C1 Pacific NW Labs, Environm Mol Sci Lab, Richland, WA 99353 USA. RP Arnett, DC (reprint author), Pacific NW Labs, Environm Mol Sci Lab, Richland, WA 99353 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2712-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3273 BP 244 EP 255 DI 10.1117/12.306115 PG 12 WC Optics SC Optics GA BL12Y UT WOS:000074381300026 ER PT S AU Chandler, DW Neyer, DW Heck, AJR AF Chandler, DW Neyer, DW Heck, AJR BE Hepburn, JW Continetti, RE Johnson, MA TI High resolution photoelectron images and D+ photofragment images following 532-nm photolysis of D-2 SO LASER TECHNIQUES FOR STATE-SELECTED AND STATE-TO-STATE CHEMISTRY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Techniques for State-Selected and State-to-State Chemistry IV CY JAN 29-31, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE ion imaging; Velocity Mapping; 532-nm laser light; D-2 photolysis; bond softening; above threshold ionization AB The non-resonant ionization and dissociation of D-2, by intense 532-nm laser light is studied by a variation of the "Ion Imaging" technique called "Velocity Mapping". Images of the both the photoelectrons and D+ photofragments are obtained and analysed at two different laser intensities. Results are compared to previous studies and several differences are discussed. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Chandler, DW (reprint author), Sandia Natl Labs, MS9055, Livermore, CA 94550 USA. RI Heck, Albert/D-7098-2011 OI Heck, Albert/0000-0002-2405-4404 NR 0 TC 7 Z9 7 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2710-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3271 BP 104 EP 113 DI 10.1117/12.308400 PG 10 WC Chemistry, Physical; Optics; Physics, Atomic, Molecular & Chemical SC Chemistry; Optics; Physics GA BL12W UT WOS:000074380900012 ER PT S AU Rao, RM Beuhler, RJ White, MG AF Rao, RM Beuhler, RJ White, MG BE Dai, HL Freund, HJ TI Non-thermal photodesorption of N-2 from Ag (111) SO LASER TECHNIQUES FOR SURFACE SCIENCE III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Techniques for Surface Science III CY JAN 29-31, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE photodesorption; state-selective detection; nitrogen; Ag (111) AB We have measured translational and rotational energy distributions of N-2 molecules following desorption from a Ag(lll) surface by infrared (1064 nm) radiation. The observed desorption yields were large even at laser fluences far below that required for laser-induced thermal desorption. State-resolved laser techniques using coherent VUV radiation showed that the rotational and translational energy distributions of the desorbing N-2 molecules are not consistent with the predictions of the heat diffusion model governing laser-induced surface heating. These results suggest that physisorbed adsorbates can couple directly to the nascent-phonon distribution or the nascent electron-hole pairs in the photoexcited substrate without heating of the surface. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Rao, RM (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2711-X J9 P SOC PHOTO-OPT INS PY 1998 VL 3272 BP 134 EP 142 DI 10.1117/12.307122 PG 9 WC Chemistry, Physical; Optics; Spectroscopy SC Chemistry; Optics; Spectroscopy GA BL12X UT WOS:000074381100018 ER PT S AU Campbell, HL Visuri, SR Da Silva, LB AF Campbell, HL Visuri, SR Da Silva, LB BE Jacques, SL Katzir, A TI Effects of stress waves on cells SO LASER-TISSUE INTERACTION IX. PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction IX CY JAN 26-28, 1998 CL SAN JOSE, CA SP USAF Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers DE stress wave; cell damage; photoacoustic AB Laser induced stress waves are being used in a variety of medical applications, including drug delivery and targeted tissue disruption. Stress waves can also be an undesirable side effect in laser procedures such as ophthalmology and angioplasty. Thus, a study of the effects of stress waves on a cellular level is useful. Thermoelastic stress waves were produced using a Q-switched frequency-doubled Nd:YAG laser (lambda=532 nm) with a pulse duration of 4 ns. The laser radiation was delivered to an absorbing media. A thermoelastic stress wave was produced in the absorbing media and propagated into plated cells. The energy per pulse delivered to a sample and the spot size were varied. Stress waves were quantified. We assayed for cell viability and damage using two methods. The threshold laser parameters for cell damage were defined for three cell lines. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Campbell, HL (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2693-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3254 BP 92 EP 96 DI 10.1117/12.308152 PG 5 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BL09D UT WOS:000074238700012 ER PT S AU Sathyam, US Celliers, PM Da Silva, LB AF Sathyam, US Celliers, PM Da Silva, LB BE Jacques, SL Katzir, A TI Interferometric technique to measure shock-induced surface velocities in tissues for the determination of dynamic mechanical properties SO LASER-TISSUE INTERACTION IX. PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction IX CY JAN 26-28, 1998 CL SAN JOSE, CA SP USAF Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers DE stress wave; velocity interferometry; spallation; VISAR AB We present an interferometric technique to measure free surface velocities of a tissue phantom when subjected to a high power laser pulse. Such information is useful for the determination of the dynamic mechanical properties of tissues and tissue phantoms. We deliver a 4-nanosecond doubled Nd:YAG laser pulse to a tamped surface of a slab sample and probe the opposite free surface with a HeNe laser beam. The stress-wave induced motion of the rear-surface imparts a Doppler shift to the reflected HeNe probe. We monitor the Doppler shift with a velocity interferometer sensitive to velocities as low as 1-2 m/s. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Sathyam, US (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2693-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3254 BP 97 EP 103 DI 10.1117/12.308153 PG 7 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BL09D UT WOS:000074238700013 ER PT S AU Kim, BM Feit, MD Rubenchik, AM Gold, DM Stuart, BC Da Silva, LB AF Kim, BM Feit, MD Rubenchik, AM Gold, DM Stuart, BC Da Silva, LB BE Jacques, SL Katzir, A TI Ultrashort pulse laser ablation of biological tissue SO LASER-TISSUE INTERACTION IX. PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction IX CY JAN 26-28, 1998 CL SAN JOSE, CA SP USAF Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers DE ultrashort pulse lasers; tissue ablation; laser-tissue interaction modeling; pulse width effect AB Temperature and shock wave propagation in water (as a model of tissue) irradiated by subpicosecond and nanosecond pulses were modeled. The high temperature and pressure generated during sub-picosecond irradiation did not penetrate deeply into the water due to quickly ejected plasma while significant pressure and temperature increases were observed in deep regions with nanosecond pulses. Knowing that the sub-picosecond pulses are effective for tissue ablation, additional studies were done to examine the effect of short pulse widths (< 20 ps). Ablation threshold, temperature rise and ablation crater quality on human dentine were investigated for different pulse widths in the range of 150 fs - 20 ps. The ablation threshold fluence was approximately 4 times higher with 20 ps pulses than with 150 fs pulses but the quality of the ablation craters were not significantly different in this pulse width range. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Kim, BM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Stuart, Brent/K-4988-2015 NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2693-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3254 BP 203 EP 210 DI 10.1117/12.308165 PG 8 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BL09D UT WOS:000074238700025 ER PT S AU Hermes, RE Trajkovska, K AF Hermes, RE Trajkovska, K BE Jacques, SL Katzir, A TI Synthetic thrombus model for in vitro studies of laser thrombolysis SO LASER-TISSUE INTERACTION IX. PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction IX CY JAN 26-28, 1998 CL SAN JOSE, CA SP USAF Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers DE thrombolysis; laser; gelatin; egg; thrombus; guar; starch AB Laser thrombolysis is the controlled ablation of a thrombus (blood clot) blockage in a living arterial system. Theoretical modeling of the interaction of laser light with thrombi relies on the ability to perform in vitro experiments with well characterized surrogate materials. A synthetic thrombus formulation may offer more accurate results when compared to in vivo clinical experiments. We describe here the development of new surrogate materials based on formulations incorporating chicken egg, guar gum, modified food starch, and a laser light absorbing dye. The sound speed and physical consistency of the materials were very close to porcine (arterial) and human (venous) thrombi. Photographic and videotape recordings of pulsed dye laser ablation experiments under various experimental conditions were used to evaluate the new material as compared to in vitro tests with human (venous) thrombus. The characteristics of ablation and mass removal were similar to that of real thrombi, and therefore provide a more realistic model for in vitro laser thrombolysis when compared to gelatin. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hermes, RE (reprint author), Univ Calif Los Alamos Natl Lab, MST-7 E549, Los Alamos, NM 87545 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2693-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3254 BP 211 EP 217 DI 10.1117/12.308166 PG 7 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BL09D UT WOS:000074238700026 ER PT S AU Bailey, DS London, RA Alley, WE AF Bailey, DS London, RA Alley, WE BE Jacques, SL Katzir, A TI Hard tissue ablation simulations using the LATIS computer code SO LASER-TISSUE INTERACTION IX. PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction IX CY JAN 26-28, 1998 CL SAN JOSE, CA SP USAF Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers DE ablation; hard tissue; simulation; short-pulse lasers AB A simulation code for analyzing laser matter interactions is described in the context of short pulse laser ablation of hard tissue. Some experimental results on short pulse laser absorption are presented and used to motivate employing such systems for ablating biological tissues. Results of simulations of hard tissue drilling are given, including hydrodynamic response and ablation efficiency. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Bailey, DS (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2693-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3254 BP 232 EP 240 DI 10.1117/12.308169 PG 9 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BL09D UT WOS:000074238700028 ER PT S AU London, RA Bailey, DS Amendt, P Visuri, S Esch, V AF London, RA Bailey, DS Amendt, P Visuri, S Esch, V BE Jacques, SL Katzir, A TI A scaling model for laser-produced bubbles in soft tissue SO LASER-TISSUE INTERACTION IX. PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction IX CY JAN 26-28, 1998 CL SAN JOSE, CA SP USAF Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers AB The generation of vapor-driven bubbles is common in many emerging laser-medical therapies involving soft tissues. To successfully apply such bubbles to processes such as tissue break-up and removal, it is critical to understand their physical characteristics. To complement previous experimental and computational studies, an analytic mathematical model for bubble creation and evolution is presented. In this model, the bubble is assumed to be spherically symmetric, and the laser pulse length is taken to be either very short or very long compared to the bubble expansion timescale. The model is based on the Rayleigh cavitation bubble model. In this description, the exterior medium is assumed to be an infinite incompressible fluid, while the bubble interior consists of a mixed liquid-gas medium which is initially heated by the laser. The heated interior provides the driving pressure which expands the bubble. The interior region is assumed to be adiabatic and is described by the standard water equation-of-state, available in either tabular, or analytic forms. Specifically, we use adiabats from the equation-of-state to describe the evolution of the interior pressure with bubble volume. Analytic scaling laws are presented for the maximum size and duration of bubbles as functions of the laser energy and initially heated volume. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP London, RA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2693-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3254 BP 256 EP 263 DI 10.1117/12.308172 PG 8 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BL09D UT WOS:000074238700031 ER PT S AU Scammon, RJ Chapyak, EJ Godwin, RP Vogel, A AF Scammon, RJ Chapyak, EJ Godwin, RP Vogel, A BE Jacques, SL Katzir, A TI Simulations of shock waves and cavitation bubbles produced in water by picosecond and nanosecond laser pulses SO LASER-TISSUE INTERACTION IX. PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction IX CY JAN 26-28, 1998 CL SAN JOSE, CA SP USAF Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers DE bubble dynamics; cavitation; experimental and numerical hydrodynamics; shocks; laser medical applications AB We compare numerical simulations of bubble dynamics in water with experiments performed at the Medizinisches Laserzentrum Lubeck. Spatial and temporal features of the laser beam were modeled. Plasma growth was predicted using a moving breakdown model. We compare the measured and calculated positions of the shock front and the bubble wail as a function of time after optical breakdown in water. Nd:YAG laser pulses of 30-ps 1-mJ and 6-ns 10-mJ were simulated. We have extended previous work in which picosecond deposition was modeled as temporally instantaneous and spatially uniform(1). C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Scammon, RJ (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2693-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3254 BP 264 EP 275 DI 10.1117/12.308173 PG 12 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BL09D UT WOS:000074238700032 ER PT S AU Amendt, P London, RA Strauss, M Glinsky, ME Maitland, DJ Celliers, PM Visuri, SR Bailey, DS Young, DA Ho, D Lin, CP Kelly, MW AF Amendt, P London, RA Strauss, M Glinsky, ME Maitland, DJ Celliers, PM Visuri, SR Bailey, DS Young, DA Ho, D Lin, CP Kelly, MW BE Delacretaz, GP Godlewski, G Pini, R Steiner, RW Svaasand, LO Katzir, A TI Simulation studies of vapor bubble generation by short-pulse lasers SO LASER-TISSUE INTERACTION, TISSUE OPTICS, AND LASER WELDING III, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Laser-Tissue Interaction, Tissue Optics, and Laser Welding III Conference CY SEP 05-08, 1997 CL SAN REMO, ITALY SP Soc Italiana Laser Chirurg & Med, European Laser Assoc, Int Biomed Opt Soc, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev DE short-pulse laser; hydrodynamics; bubble; shock wave; melanosome AB Formation of vapor bubbles is characteristic of many applications of short-pulse lasers in medicine. An understanding of the dynamics of vapor bubble generation is useful for developing and optimizing laser-based medical therapies. To this end, experiments in vapor bubble generation with laser light deposited in an aqueous dye solution near a fiber-optic tip have been performed. Numerical hydrodynamic simulations have been developed to understand and extrapolate results from these experiments. Comparison of two-dimensional simulations with the experiment shows excellent agreement in tracking the bubble evolution. Another regime of vapor bubble generation is short-guise laser interactions with melanosomes. Strong shock generation and vapor bubble generation are common physical features of this interaction. A novel effect of discrete absorption by melanin granules within a melanosome is studied as a possible role in previously reported high Mach number shocks [Lin and Kelly, SPIE 2391, 294 (1995)]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Amendt, P (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2627-X J9 P SOC PHOTO-OPT INS PY 1998 VL 3195 BP 259 EP 272 DI 10.1117/12.297909 PG 14 WC Engineering, Biomedical; Medicine, Research & Experimental; Optics SC Engineering; Research & Experimental Medicine; Optics GA BK38W UT WOS:000071968300032 ER PT J AU Small, W Celliers, PM Kopchok, GE Reiser, KM Heredia, NJ Maitland, DJ Eder, DC London, RA Heilbron, M Hussain, F White, RA Da Silva, LB Matthews, DL AF Small, W Celliers, PM Kopchok, GE Reiser, KM Heredia, NJ Maitland, DJ Eder, DC London, RA Heilbron, M Hussain, F White, RA Da Silva, LB Matthews, DL TI Temperature feedback and collagen cross-linking in argon laser vascular welding SO LASERS IN MEDICAL SCIENCE LA English DT Article DE collagen; infrared thermometry; radiometry; temperature; tissue fusion ID TISSUE; CROSSLINKING; SIMULATIONS; MECHANISM; MONKEYS; LIGHT; SKIN; LUNG AB A preliminary single-animal study of in vivo argon laser vascular welding was conducted using a canine model. The effects of temperature feedback control and saline drip cooling on patency and collagen cross-linking were investigated. The surface temperature at the centre of the laser spot was monitored using a two-colour infrared thermometer. The surface temperature was limited by either a saline drip or feedback control of the laser. Acute patency was evaluated and collagen cross-link assays were performed. Though both protocols yielded successful tissue fusion, welds maintained at a surface temperature of 50 degrees C using feedback control had an elevated cross-link count compared to controls, whereas tissues irradiated without feedback control experienced a cross-link decrease. Simulations using the LATIS (LAser-TISsue) computer code suggest that drip-cooled procedures achieve significantly higher temperatures beneath the tissue surface than temperature feedback-controlled procedures. Differences between the volumetric heating associated with drip-cooled and feedback-controlled protocols may account for the different effects on collagen cross-links. Covalent mechanisms may play a role in argon laser vascular fusion. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Los Angeles, Med Ctr, Div Vasc Surg, Torrance, CA 90509 USA. Univ Calif Davis, Sch Med, Dept Med, Davis, CA USA. RP Small, W (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-399,POB 808, Livermore, CA 94550 USA. NR 28 TC 14 Z9 14 U1 3 U2 4 PU SPRINGER-VERLAG LONDON LTD PI GODALMING PA SWEETAPPLE HOUSE CATTESHALL ROAD, GODALMING GU7 3DJ, SURREY, ENGLAND SN 0268-8921 J9 LASER MED SCI JI Lasers Med. Sci. PY 1998 VL 13 IS 2 BP 98 EP 105 DI 10.1007/s101030050061 PG 8 WC Engineering, Biomedical; Surgery SC Engineering; Surgery GA 101VM UT WOS:000074888900003 ER PT J AU Hill, RA Ren, Q Nguyen, DC Liaw, LH Berns, MW AF Hill, RA Ren, Q Nguyen, DC Liaw, LH Berns, MW TI Free-electron laser (FEL) ablation of ocular tissues SO LASERS IN MEDICAL SCIENCE LA English DT Article; Proceedings Paper CT 1995 Annual Meeting of the Association-for-Research-in-Vision-and-Ophthalmology CY MAY 14-19, 1995 CL FT LAUDERDALE, FLORIDA SP Assoc Res Vis & Ophthalmol DE laser; surgery; trabecular meshwork; wavelength ID SOLID-STATE LASER; ERBIUM-YAG LASER; 213-NM PHOTOREFRACTIVE KERATECTOMY; EXCIMER-LASER; ER-YAG; CORNEAL INCISIONS; PULSE DURATION; THERMAL-DAMAGE; FOLLOW-UP; 193 NM AB The purpose of the present study was to investigate the ablation characteristics of free-electron laser (FEL) pulses at 5.3 mu m and 6.0 mu m on ocular tissues. The advanced FEL was developed by the Los Alamos National Laboratory. It operates in the 4-7 mu m range, with a macropulse duration of 10 mu s and repetition rate of 10 Hz. Each macropulse consists of a train of micropulses that are lj ps in pulse duration separated by 10 ns. The output energy of macropulses can be adjusted from 5 to 120 mJ. Five transplant grade corneal-scleral buttons preserved in corneal storage medium were used. Wavelengths 5.3 and 6.0 mu m were selected based on Fourier-transform infrared absorption spectra of a type I collagen film. Ocular tissue cuts made at 6.0 mu m revealed a well-defined ablation boundary with a lateral tissue damage at 10 +/- 2 mu m. The ablation boundary of the corneal cuts made at 5.3 mu m revealed tissue disruption with thermally denatured tissue constituents with loss of organised structure. The lateral dimension of this effect extended up to 220 mu m. It was concluded first that Fourier-transform infrared absorption spectra may be useful in selecting laser ablation wavelengths, and second that lasers emitting near 6 mu m achieve excellent spatial confinement of laser energy secondary to both protein and water energy partitioning, This wavelength may have potential for cutting ocular tissue such as cornea, sclera, vitreous or lens, because of energy partitioning. C1 Univ Calif Irvine, Dept Ophthalmol, Irvine, CA 92697 USA. Univ Calif Irvine, Beckman Laser Inst & Med Clin, Irvine, CA 92697 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Hill, RA (reprint author), Univ Calif Irvine, Dept Ophthalmol, Med Surg 1,Rm 118, Irvine, CA 92697 USA. RI Ren, Qiushi/D-1451-2012 NR 56 TC 8 Z9 8 U1 0 U2 0 PU SPRINGER-VERLAG LONDON LTD PI GODALMING PA SWEETAPPLE HOUSE CATTESHALL ROAD, GODALMING GU7 3DJ, SURREY, ENGLAND SN 0268-8921 J9 LASER MED SCI JI Lasers Med. Sci. PY 1998 VL 13 IS 3 BP 219 EP 226 DI 10.1007/s101030050078 PG 8 WC Engineering, Biomedical; Surgery SC Engineering; Surgery GA 145UZ UT WOS:000077391000011 ER PT S AU Godwin, RP Chapyak, EJ Prahl, SA Shangguan, HQ AF Godwin, RP Chapyak, EJ Prahl, SA Shangguan, HQ BE Anderson, RR Bartels, KE Bass, LS Garrett, CG Gregory, KW Lui, H Malek, RS Perlmutter, AP Reinisch, L Smalley, PJ Tate, LP Thomsen, SL Watson, GM Katzir, A TI Laser mass ablation efficiency measurements indicate bubble-driven dynamics dominates laser thrombolysis SO LASERS IN SURGERY: ADVANCED CHARACTERIZATION, THERAPEUTICS, AND SYSTEMS VIII, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Lasers in Surgery - Advanced Characterization, Therapeutics, and Systems VIII CY JAN 24-25, 1998 CL SAN JOSE, CA SP Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers DE bubble dynamics; cavitation; hydrodynamics; jet formation; laser thrombolysis; mass ablation efficiency AB Mass removal experiments have been performed at the Oregon Medical Laser Center with 10 to 100 mJ 1 mu s laser pulses at optical wavelengths. Above the energy threshold for bubble formation, the laser mass ablation efficiency (mu g/mJ) for removal of gel surrogate thrombus is nearly constant for a given experimental geometry and gel absorption coefficient. The efficiency in "contact" experiments, in which the optical fiber delivering the energy is in close proximity to the absorbing gel, is approximately three times that of "non-contact" experiments, in which the optical fiber is similar to 1 mm from the gel. Mass removal occurs hundreds of microseconds after the laser deposition. Experimental data and numerical simulations are consistent with the hypothesis that jet formation during bubble collapse plays a dominant role in mass removal. This hypothesis suggests a model in which the mass removed scales linearly with the maximum bubble volume and explains the distinctive features, including the magnitude, of the mass removal. C1 Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87545 USA. RP Godwin, RP (reprint author), Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, MS F664, Los Alamos, NM 87545 USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2684-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3245 BP 4 EP 11 DI 10.1117/12.312278 PG 8 WC Dermatology; Optics; Otorhinolaryngology; Surgery; Veterinary Sciences SC Dermatology; Optics; Otorhinolaryngology; Surgery; Veterinary Sciences GA BL37M UT WOS:000075318900001 ER PT S AU Chapyak, EJ Godwin, RP AF Chapyak, EJ Godwin, RP BE Anderson, RR Bartels, KE Bass, LS Garrett, CG Gregory, KW Lui, H Malek, RS Perlmutter, AP Reinisch, L Smalley, PJ Tate, LP Thomsen, SL Watson, GM Katzir, A TI Physical mechanisms of importance to Laser Thrombolysis SO LASERS IN SURGERY: ADVANCED CHARACTERIZATION, THERAPEUTICS, AND SYSTEMS VIII, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Lasers in Surgery - Advanced Characterization, Therapeutics, and Systems VIII CY JAN 24-25, 1998 CL SAN JOSE, CA SP Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers DE Laser Thrombolysis; bubble dynamics; numerical methods; hydrodynamics; material properties; tissue properties AB Bubble dynamics plays a key role in many medical procedures including Laser Thrombolysis (L-T), acoustic and laser lithotripsy, interocular laser surgery, photoacoustic drug delivery, and perhaps ultrasonic imaging. We are investigating the effect that interfaces of different materials, especially biological and biomedical materials, have on the dynamics of nearby bubbles. Collapsing bubbles often become nonspherical, resulting in spectacular directed motion with potentially both beneficial and undesirable consequences. This directed motion may explain L-T mass removal and some types of laser-induced tissue damage. C1 Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87545 USA. RP Chapyak, EJ (reprint author), Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 11 Z9 11 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2684-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3245 BP 12 EP 18 DI 10.1117/12.312270 PG 7 WC Dermatology; Optics; Otorhinolaryngology; Surgery; Veterinary Sciences SC Dermatology; Optics; Otorhinolaryngology; Surgery; Veterinary Sciences GA BL37M UT WOS:000075318900002 ER PT S AU Small, W Da Silva, LB Matthews, DL AF Small, W Da Silva, LB Matthews, DL BE Anderson, RR Bartels, KE Bass, LS Garrett, CG Gregory, KW Lui, H Malek, RS Perlmutter, AP Reinisch, L Smalley, PJ Tate, LP Thomsen, SL Watson, GM Katzir, A TI Spectroscopic study of the effect of laser heating on collagen stability: Implications for tissue welding SO LASERS IN SURGERY: ADVANCED CHARACTERIZATION, THERAPEUTICS, AND SYSTEMS VIII, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Lasers in Surgery - Advanced Characterization, Therapeutics, and Systems VIII CY JAN 24-25, 1998 CL SAN JOSE, CA SP Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers DE cornea; dehydration; denaturation; Fourier transform infrared spectroscopy; temperature feedback AB Collagen is believed to play a major role in laser tissue welding. Furthermore, the fundamental fusion mechanism(s) may include thermal denaturation of the collagen fibers. An in vitro a investigation of the effect of laser heating (1.9 mu m diode laser) on collagen conformation was performed. Fourier transform infrared (FTIR) spectra of native and heated porcine cornea were obtained. A low-frequency shift in the amide A band of collagen around 3320 cm(-1) indicated that conformational changes associated with denaturation occurred. Samples heated using a temperature feedback controlled 1.9 mu m diode laser showed a gradual decrease in the amide A peak frequency with increasing temperature, as did samples heated in a water bath. Complete denaturation was achieved at temperatures above 85 degrees C for both heating protocols. Water loss induced by laser heating may have reduced the mobility of Me collagen polypeptide chains, and contributed to the elevated denaturation temperature. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Small, W (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-399,POB 808, Livermore, CA 94550 USA. NR 0 TC 2 Z9 2 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2684-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3245 BP 276 EP 281 DI 10.1117/12.312298 PG 6 WC Dermatology; Optics; Otorhinolaryngology; Surgery; Veterinary Sciences SC Dermatology; Optics; Otorhinolaryngology; Surgery; Veterinary Sciences GA BL37M UT WOS:000075318900035 ER PT S AU Lobrich, M AF Lobrich, M BE Reitz, G Kronenberg, A TI Induction and repair of DNA double-strand breaks in human fibroblasts after particle irradiation SO LIFE SCIENCES: RECENT DOSIMETRY RESULTS, CHROMOSOME DAMAGE AND HERITABLE EFFECTS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 6 and F2 9 Symposia of COSPAR Scientific Commission F at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Int Council Sci Unions, Comm Space Res ID FIELD GEL-ELECTROPHORESIS; HEAVY CHARGED-PARTICLES; HIGH-ENERGY NEON; MAMMALIAN-CELLS; IONIZING-RADIATION; ALPHA-PARTICLES; IRON IONS; FRAGMENTS AB Two assay were employed to study the induction and repair of DNA double-strand breaks (dsbs) in normal human fibroblasts after exposure to particle radiation covering an LET range from I to 350 keV/mu m. The hybridization assay allows measurement of absolute induction frequencies in defined regions of the genome and quantitates rejoining of correct DNA ends while the FAR assay determines all rejoining events, correct and incorrect. Assuming Poisson statistics for the number of breaks per DNA fragment investigated, and thus neglecting any clustering of breaks, we found the induction rate to decrease with increasing LET of the particles. RBE values compared to 225 kVp X-rays dropped to 0.48 for the highest LETs. Repair studies of X-ray-induced dsbs showed that almost all breaks ( >95%) are rejoined after incubation times of 24 h while the frequency for correct rejoining is only 70%. Thus about 25% of the initially induced breaks are rejoined by the connection of incorrect DNA ends. Postirradiation incubation after particle irradiation showed less efficient total rejoining with increasing LET and an impaired ability for correct rejoining. The frequency for rejoining of incorrect DNA ends was found to be independent of LET. The possible biological significance of the different rejoining events is discussed. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Lobrich, M (reprint author), Univ Giessen, Strahlenzentrum, D-6300 Giessen, Germany. NR 18 TC 5 Z9 5 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043468-1 J9 ADV SPACE RES PY 1998 VL 22 IS 4 BP 551 EP 560 DI 10.1016/S0273-1177(98)00077-5 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Genetics & Heredity; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Genetics & Heredity; Geology; Meteorology & Atmospheric Sciences GA BL54Y UT WOS:000075849900010 PM 11542785 ER PT S AU Waldren, C Vannais, D Drabek, R Gustafson, D Kraemer, S Lenarczyk, M Kronenberg, A Hei, T Ueno, A AF Waldren, C Vannais, D Drabek, R Gustafson, D Kraemer, S Lenarczyk, M Kronenberg, A Hei, T Ueno, A BE Reitz, G Kronenberg, A TI Analysis of mutant quantity and quality in human-hamster hybrid A(L) and A(L)-179 cells exposed to Cs-137-gamma or HZE-Fe ions SO LIFE SCIENCES: RECENT DOSIMETRY RESULTS, CHROMOSOME DAMAGE AND HERITABLE EFFECTS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 6 and F2 9 Symposia of COSPAR Scientific Commission F at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Int Council Sci Unions, Comm Space Res ID LINEAR-ENERGY-TRANSFER; HUMAN FIBROBLASTS; MAMMALIAN-CELLS; STRAND BREAKS; CHROMOSOMAL INSTABILITY; MUTATION-INDUCTION; MOLECULAR ANALYSIS; HEAVY-IONS; IRON IONS; RADIATION AB We measured the number of mutants and the kinds of mutations induced by Cs-137-gamma and by HZE-Fe (Fe-56 [600 MeV/amu, LET = 190 KeV/mu m]) in standard A(L) human hamster hybrid cells and in a new variant hybrid,A(L)-179. We found that HZE-Fe was more mutagenic than Cs-137-gamma pe, unit dose (about 1.6 fold), but was slightly less mutagenic per mean lethal dose, D-o, at both the S1 and hprt loci of A(L) cells. On the other hand, HZE-Fe induced about nine fold more complex S1(-) mutants than Cs-137-gamma rays, 28% vs 3%. Cs-137-gamma rays induced about twice as many S1(-) mutants and hprt(-) mutants in A(L)-179 as in A(L) cells, and about nine times more of the former were complex, and potentially unstable kinds of mutations. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 Colorado State Univ, Dept Radiol Hlth Sci MRB, Ft Collins, CO 80523 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Columbia Univ, Ctr Radiol Res, New York, NY 10032 USA. RP Waldren, C (reprint author), Colorado State Univ, Dept Radiol Hlth Sci MRB, Ft Collins, CO 80523 USA. FU NCI NIH HHS [CA36447] NR 27 TC 19 Z9 19 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043468-1 J9 ADV SPACE RES PY 1998 VL 22 IS 4 BP 579 EP 585 DI 10.1016/S0273-1177(98)00080-5 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Genetics & Heredity; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Genetics & Heredity; Geology; Meteorology & Atmospheric Sciences GA BL54Y UT WOS:000075849900013 PM 11542788 ER PT S AU Vazquez, ME AF Vazquez, ME BE Vazquez, ME TI Neurobiological problems in long-term deep space flights SO LIFE SCIENCES: SPACE FLIGHT AND THE CENTRAL NERVOUS SYSTEM: THE POTENTIAL INDEPENDENT AND SYNERGISTIC EFFECTS OF MICROGRAVITY AND RADIATION SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 4 Symposium of COSPAR Scientific Commission F at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Deut Agentur Raum Fahrt, Angelegenheiten GmbH ID CENTRAL-NERVOUS-SYSTEM; HEAVY-PARTICLE IRRADIATION; AGING BRAIN; RADIATION PROTECTION; SYNAPTIC PLASTICITY; ALZHEIMERS-DISEASE; GENE-EXPRESSION; STRAND BREAKS; IN-SPACE; MICROGRAVITY AB Future missions in space may involve long-term travel beyond the magnetic field of the Earth, subjecting astronauts to radiation hazards posed by solar flares and galactic cosmic rays, altered gravitation fields and physiological stress. Thus, it is critical to determine if there will be any reversible or irreversible, detrimental neurological effects from this prolonged exposure to space. A question of particular importance focuses on the long-term effects of the space environment on the central nervous system (CNS) neuroplasticity, with the potential acute and/or delayed effects that such perturbations might entail. Although the short-term effects of microgravity on neural control were studied on previous low earth orbit missions, the late consequences of stress in space, microgravity and space radiation have not been addressed sufficiently at the molecular, cellular and tissue levels. The possibility that space flight factors can interact influencing the neuroplastic response in the CNS looms critical issue not only to understand the ontogeny of the CNS and its functional integrity, but also, ultimately the performance of astronauts in extended space forays. The purpose of this paper is to review the neurobiological modifications that occur in the CNS exposed to the space environment, and its potential consequences for extended deep space flight. Published by Elsevier Science Ltd on behalf of COSPAR. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Vazquez, ME (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 91 TC 17 Z9 17 U1 4 U2 5 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043466-5 J9 ADV SPACE RES PY 1998 VL 22 IS 2 BP 171 EP 183 DI 10.1016/S0273-1177(98)80009-4 PG 13 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Neurosciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences; Neurosciences & Neurology GA BL56Q UT WOS:000075898700001 PM 11541395 ER PT S AU Curtis, SB Vazquez, ME Wilson, JW Atwell, W Kim, M Capala, J AF Curtis, SB Vazquez, ME Wilson, JW Atwell, W Kim, M Capala, J BE Vazquez, ME TI Cosmic ray hit frequencies in critical sites in the central nervous system SO LIFE SCIENCES: SPACE FLIGHT AND THE CENTRAL NERVOUS SYSTEM: THE POTENTIAL INDEPENDENT AND SYNERGISTIC EFFECTS OF MICROGRAVITY AND RADIATION SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 4 Symposium of COSPAR Scientific Commission F at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Deut Agentur Raum Fahrt, Angelegenheiten GmbH ID HEAVY-PARTICLE IRRADIATION; HUMAN RETINA; GANGLION-CELLS; BASAL NUCLEUS; RADIATION; SPACE; NEURONS; HIPPOCAMPUS; TRANSPORT; NUMBER AB One outstanding question to be addressed in assessing the risk of exposure to space travelers from galactic cosmic rays (GCR) outside the geomagnetosphere is to ascertain the effects of single heavy-ion hits on cells in critical regions of the central nervous system (CNS), As a first step toward this end, it is important to determine how many "hits" might be received by a neural cell in several critical CNS areas during an extended mission outside the confines of the earth's magnetic field, Critical sites in the CNS: the macula, and an interior brain point (typical of the genu, thalamus, hippocampus and nucleus basalis of Meynert) were chosen for the calculation of hit frequencies from galactic cosmic rays for a mission to Mars during solar minimum (i.e., at maximum cosmic-ray intensity), The shielding at a given position inside the body was obtained using the Computerized Anatomical Man (CAM) model, and a radiation transport code which includes nuclear fragmentation was used to calculate yearly fluences at the point of interest, Since the final Mars spacecraft shielding configuration has not yet been determined, we considered the minimum amount of aluminum required for pressure vessel-wall requirements in the living quarters of a spacecraft, and a typical duty area as a pressure vessel plus necessary equipment, The conclusions are: (1) variation of the position of the "target site" within the head plays only a small role in varying hit frequencies; (2) the average number of hits depends linearly on the cross section of the critical portion of the cell assumed in the calculation; (3) for a three-year mission to Mars at solar minimum (i.e,, assuming the 1977 spectrum of galactic cosmic rays), 2% or 13% of the "critical sites" of cells in the CNS would be directly hit at least once by iron ions, depending on whether 60 mu m(2) or 471 mu m(2) is assumed as the critical cross sectional area; and (4) roughly 6 million out of some 43 million hippocampal cells and 55 thousand out of 1.8 million thalamus cell nuclei would be directly hit by iron ions at least once on such a mission for space travelers inside a simple pressure vessel. Also, roughly 20 million out of 43 million hippocampal cells and 230 thousand out of 1.8 million thalamus cell nuclei would be directly hit by one or more particles with z greater than or equal to 15 on such a mission, (C) 1998 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Fred Hutchinson Canc Res Ctr, Seattle, WA 98104 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Aerosp Rockwell, Houston, TX 77058 USA. RP Curtis, SB (reprint author), Fred Hutchinson Canc Res Ctr, MP-665,1124 Columbia St, Seattle, WA 98104 USA. NR 54 TC 25 Z9 26 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043466-5 J9 ADV SPACE RES PY 1998 VL 22 IS 2 BP 197 EP 207 DI 10.1016/S0273-1177(98)80011-2 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Neurosciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences; Neurosciences & Neurology GA BL56Q UT WOS:000075898700003 PM 11541397 ER PT B AU Naus, D Oland, CB Ellingwood, B Norris, WE Graves, HL AF Naus, D Oland, CB Ellingwood, B Norris, WE Graves, HL BE Edwards, JH Flewitt, PEJ Gasper, BC McLarty, KA Stanley, P Tomkins, B TI Management of aging of nuclear power plant containment structures SO LIFETIME MANAGEMENT AND EVALUATION OF PLANT, STRUCTURES AND COMPONENTS LA English DT Proceedings Paper CT 4th International Conference on Engineering Structural Integrity Assessment CY SEP 22-24, 1998 CL CHURCHILL COLL, CAMBRIDGE, ENGLAND SP AEA Technol plc, Rolls Royce, BNFL Magnox Generat, Somat Syst, Dartec, TWI, Engn Integr Soc, Soc Environm Engineers, British Inst Non Destruct Testing, Inst Mat, Inst Phys, Inst Mech Engineers, Mech Reliabil Comm HO CHURCHILL COLL ID CONCRETE STRUCTURES AB Research addressing aging management of nuclear power plant concrete and steel containment structures is summarized. Accomplishments related to concrete containment structures include formation of a materials' property database; an aging assessment methodology to identify critical structures and degradation factors; guidelines and evaluation criteria for use in condition assessments; and a time-dependent reliability-based methodology for condition assessments and estimations of future performance. Under the steel containments and liners activity, a degradation assessment methodology has been developed, mathematical models that describe time-dependent changes in the containment due to aggressive environmental factors have been identified, and statistical data supporting the use of these models in time-dependent reliability analysis have been summarized. C1 Oak Ridge Natl Lab, Engn Technol Div, Oak Ridge, TN 37831 USA. RP Naus, D (reprint author), Oak Ridge Natl Lab, Engn Technol Div, Oak Ridge, TN 37831 USA. NR 27 TC 0 Z9 0 U1 0 U2 0 PU ENGINEERING MATERIALS ADVISORY SERVICES LTD PI SHEFFIELD PA C/O NCODE, 230 WOODBOURN RD, SHEFFIELD S9 3LQ, ENGLAND BN 1-901537-07-2 PY 1998 BP 491 EP 499 PG 9 WC Engineering, Environmental; Engineering, Civil SC Engineering GA BP90M UT WOS:000086563000055 ER PT S AU Barton, DL Osinski, M Perlin, P Helms, CJ Berg, NH AF Barton, DL Osinski, M Perlin, P Helms, CJ Berg, NH BE Schubert, EF TI Life tests and failure mechanisms of GaN/AlGaN/InGaN light emitting diodes SO LIGHT-EMITTING DIODES: RESEARCH, MANUFACTURING, AND APPLICATIONS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Light-Emitting Diodes - Research, Manufacturing, and Applications II CY JAN 28-29, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers AB Our studies of device lifetime and the main degradation mechanisms in Nichia blue LEDs date back to Spring 1994. Following the initial studies of rapid failures under high Current electrical:pulses, where metal migration was identified as the cause of degradation, we have placed a number of Nichia NLPB-500 LEDs on a series of life tests. The first test ran for 1000 hours under normal operating conditions (20 mA at 23 degrees C). As no noticeable degradation was observed, the second room temperature test was performed with the same devices but with a range of currents between 20 and 70 mA. After 1600 hours, some degradation in output intensity was observed in devices driven at 60 and 70 mA, but it was still less than 20%. The subsequent tests included stepping up the temperature by 10 degrees C in 500 h intervals up to a final temperature of 95 degrees C using the same currents applied in the second test. This work reviews the failure analysis that was performed on the degraded devices and the degradation mechanisms that were identified. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Barton, DL (reprint author), Sandia Natl Labs, MS 1081, Albuquerque, NM 87185 USA. NR 0 TC 11 Z9 11 U1 1 U2 6 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2718-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3279 BP 17 EP 27 DI 10.1117/12.304426 PG 11 WC Optics SC Optics GA BL04H UT WOS:000074111400003 ER PT S AU Allerman, AA Kurtz, SR Biefeld, RM Baucom, KC Burkhart, JH AF Allerman, AA Kurtz, SR Biefeld, RM Baucom, KC Burkhart, JH BE Schubert, EF TI Development of InAsSb-based light emitting diodes for chemical sensing systems SO LIGHT-EMITTING DIODES: RESEARCH, MANUFACTURING, AND APPLICATIONS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Light-Emitting Diodes - Research, Manufacturing, and Applications II CY JAN 28-29, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE InAsSb; light emitting diodes; mid-infrared LED; MOCVD AB Mid-infrared (3-6 mu m) LED's are being developed for use in chemical sensor systems. As-rich, InAsSb heterostructures are particularly suited for optical emitters in the mid-infrared region. We are investigating both InAsSb-InAs multiple quantum well (MQW) and InAsSb-InAsP strained layer superlattice (SLS) structures for use as the active region for light emitting diodes (LED's). The addition of phosphorus to the InAs barriers increases the light and heavy hole splitting and hence reduces non-radiative Auger recombination and provides for better electron and hole confinement in the InAsSb quantum well. Low temperature (<20K) photoluminescence (PL) emission from MQW structures is observed between 3.2 to 6.0 mu m for InAsSb wells between 70 to 100 Angstrom and antimony mole fractions between 0.04 to 0.18. Room temperature PL has been observed to 6.4 mu m in MQW structures. The additional confinement by InAsP barriers results in low temperature PL being observed over a narrower range (3.2 to 5.0 mu m) for the similar well thicknesses with antimony mole fractions between 0.10 to 0.24. Room temperature photoluminescence was observed to 5.8 mu m in SLS structures. The addition of a p-AlAsSb layer between the n-type active region (MQW or SLS) and a p-GaAsSb contact layer improves electron confinement of the active region and increases output power by a factor of 4. Simple LED emitters have been fabricated which exhibit an average power at room temperature of >100 mu W at 4.0 mu m for SLS active regions. These LED's have been used to detect CO2 concentrations down to 24ppm in a first generation, non-cryogenic sensor system. We will report on the development of novel LED device designs that are expected to lead to further improvements in output power. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Allerman, AA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 1 Z9 1 U1 2 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2718-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3279 BP 126 EP 133 DI 10.1117/12.304418 PG 8 WC Optics SC Optics GA BL04H UT WOS:000074111400014 ER PT B AU McDeavitt, SM Billings, GW AF McDeavitt, SM Billings, GW BE Welch, BJ TI The development of stable ceramic materials for the containment of molten zirconium and uranium alloys SO LIGHT METALS 1998 LA English DT Meeting Abstract CT 127th Annual Meeting of the Minerals-Metals-and-Materials-Society CY FEB 15-19, 1998 CL SAN ANTONIO, TX SP Mineral Metals & Mat Soc C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP McDeavitt, SM (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-390-2 PY 1998 BP 1365 EP 1365 PG 1 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BK86H UT WOS:000073691100184 ER PT B AU Dunn, PS Korzekwa, D Tubesing, P AF Dunn, PS Korzekwa, D Tubesing, P BE Welch, BJ TI Plasma arc melting of uranium-6 wt. % niobium alloys SO LIGHT METALS 1998 LA English DT Meeting Abstract CT 127th Annual Meeting of the Minerals-Metals-and-Materials-Society CY FEB 15-19, 1998 CL SAN ANTONIO, TX SP Mineral Metals & Mat Soc C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Dunn, PS (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-390-2 PY 1998 BP 1367 EP 1367 PG 1 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BK86H UT WOS:000073691100185 ER PT B AU Tubesing, PK Korzekwa, DR Dunn, PS AF Tubesing, PK Korzekwa, DR Dunn, PS BE Welch, BJ TI Carbon reduction in uranium by plasma arc melting SO LIGHT METALS 1998 LA English DT Meeting Abstract CT 127th Annual Meeting of the Minerals-Metals-and-Materials-Society CY FEB 15-19, 1998 CL SAN ANTONIO, TX SP Mineral Metals & Mat Soc C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Tubesing, PK (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-390-2 PY 1998 BP 1369 EP 1369 PG 1 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BK86H UT WOS:000073691100186 ER PT B AU Korzekwa, DR Dunn, PS Tubesing, PK AF Korzekwa, DR Dunn, PS Tubesing, PK BE Welch, BJ TI Casting of uranium and bismuth through filters: Experiments and simulations SO LIGHT METALS 1998 LA English DT Meeting Abstract CT 127th Annual Meeting of the Minerals-Metals-and-Materials-Society CY FEB 15-19, 1998 CL SAN ANTONIO, TX SP Mineral Metals & Mat Soc C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Korzekwa, DR (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-390-2 PY 1998 BP 1371 EP 1371 PG 1 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BK86H UT WOS:000073691100187 ER PT J AU Berges, JA Falkowski, PG AF Berges, JA Falkowski, PG TI Physiological stress and cell death in marine phytoplankton: Induction of proteases in response to nitrogen or light limitation SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID PROTEIN-DEGRADATION; NUCLEAR-DNA; SURVIVAL; PHOTOSYNTHESIS; SEA; SEDIMENTATION; HAPTOPHYCEAE; STARVATION; MORTALITY; PHOSPHATE AB The physiological processes of natural phytoplankton mortality due to environmental stress (vs. that caused by sedimentation and predation) are poorly understood. Cell survival was examined in batch cultures of the diatom Thalassiosira weissflogii and the chlorophyte Dunaliella tertiolecta during deprivation of fixed nitrogen or light. Despite severe impairment of photosynthetic efficiencies, both species remained viable during 2 weeks of N starvation. Under N stress, a specific protease was induced in the diatom, overall activity of proteases doubled, and there was gradual, selective loss of certain proteins, especially ribulose 1,5-bisphosphate carboxylase/oxygenase. Light-deprived diatoms were virtually unaffected, but the chlorophyte underwent catastrophic cell death after about 6 d of darkness. cell death coincided with a large increase in protease activity and the induction of a specific protease. Although we cannot completely rule out roles for viruses or bacteria in the losses of cells, the consistent timing, the unique response to stress, and the coincident expression of a specific protease strongly suggest that the process is a form of autocatalyzed cell death, such as apoptosis. While of uncertain adaptive significance, phytoplankton cell death may have implications for species succession and cycling of organic matter in aquatic ecosystems. C1 Brookhaven Natl Lab, Div Oceanog & Atmospher Sci, Upton, NY 11973 USA. RP Berges, JA (reprint author), Queens Univ Belfast, Sch Biol & Biochem, Belfast BT9 7BL, Antrim, North Ireland. RI Berges, John /D-9520-2012 OI Berges, John /0000-0002-3124-4783 NR 50 TC 175 Z9 187 U1 3 U2 29 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD JAN PY 1998 VL 43 IS 1 BP 129 EP 135 PG 7 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA ZN894 UT WOS:000073694200015 ER PT S AU Wiederrecht, GP Wasielewski, MR Galili, T Levanon, H AF Wiederrecht, GP Wasielewski, MR Galili, T Levanon, H BE Khoo, IC TI Charge transfer reactions in nematic liquid crystals SO LIQUID CRYSTALS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Liquid Crystals II CY JUL 20-21, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE liquid crystals; charge transfer; solvation dynamics ID PHOTOINDUCED ELECTRON-TRANSFER; PARAMAGNETIC-RESONANCE; ACCEPTOR MOLECULES; STATE DYNAMICS; SOLID-STATE; PORPHYRIN; RECOMBINATION; DEPENDENCE; SEPARATION; DISTANCE AB Ultrafast transient absorption studies of intramolecular photoinduced charge separation and thermal charge recombination were carried out on a molecule consisting of a 4-(N-pyrrolidino)naphthalene-1,8-imide donor (PNI) covalently attached to a pyromellitimide acceptor (PI) dissolved in the liquid crystal 4'-(n-pentyl)-4-cyanobiphenyl (5CB). The temperature dependencies of the charge separation and recombination rates were obtained at temperatures above the nematic-isotropic phase transition of 5CB, where ordered microdomains exist and scattering of visible light by these domains is absent. We show that excited state charge separation is non-adiabatic, and obtain the unexpected result that charge separation is dominated by molecular reorientation of 5CB perpendicular to the director within the liquid crystal microdomains. We also show that charge recombination is adiabatic and is controlled by the comparatively slow collective reorientation of the liquid crystal microdomains relative to the orientation of PNI+-PI-. We also report the results of time resolved electron paramagnetic resonance (TREPR) studies of photoinduced charge separation in a series of supramolecular compounds dissolved in oriented liquid crystal solvents. These studies permit the determination of the radical pair energy levels as the solvent reorganization energy increases from the low temperature crystalline phase, through the soft glass phase, to the nematic phase of the liquid crystal. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Wiederrecht, GP (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 38 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2930-9 J9 P SOC PHOTO-OPT INS PY 1998 VL 3475 BP 102 EP 111 DI 10.1117/12.326896 PG 10 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BM33A UT WOS:000078396900012 ER PT B AU Price, DL Saboungi, ML AF Price, DL Saboungi, ML BE Billinge, SJL Thorpe, MF TI Anomalous x-ray scattering from disordered materials SO LOCAL STRUCTURE FROM DIFFRACTION SE FUNDAMENTAL MATERIALS RESEARCH LA English DT Proceedings Paper CT Conference on Local Structure from Diffraction CY AUG 10-13, 1997 CL TRAVERSE CITY, MI C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Price, DL (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 13 Z9 13 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA BN 0-306-45827-6 J9 FUNDMAT RES PY 1998 BP 23 EP 33 PG 11 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Materials Science GA BL25J UT WOS:000074897500002 ER PT B AU Robertson, JL Sparks, CJ Ice, GE Jiang, X Moss, SC Reinhard, L AF Robertson, JL Sparks, CJ Ice, GE Jiang, X Moss, SC Reinhard, L BE Billinge, SJL Thorpe, MF TI Local atomic arrangements in binary solid solutions studied by x-ray and neutron diffuse scattering from single crystals SO LOCAL STRUCTURE FROM DIFFRACTION SE FUNDAMENTAL MATERIALS RESEARCH LA English DT Proceedings Paper CT Conference on Local Structure from Diffraction CY AUG 10-13, 1997 CL TRAVERSE CITY, MI C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Robertson, JL (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 1 Z9 1 U1 2 U2 2 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA BN 0-306-45827-6 J9 FUNDMAT RES PY 1998 BP 175 EP 188 PG 14 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Materials Science GA BL25J UT WOS:000074897500010 ER PT B AU Kwei, GH Louca, D Billinge, SJL Rosenfeld, HD AF Kwei, GH Louca, D Billinge, SJL Rosenfeld, HD BE Billinge, SJL Thorpe, MF TI Recent "local" structural studies: Metallic alloys, superconductors and proteins SO LOCAL STRUCTURE FROM DIFFRACTION SE FUNDAMENTAL MATERIALS RESEARCH LA English DT Proceedings Paper CT Conference on Local Structure from Diffraction CY AUG 10-13, 1997 CL TRAVERSE CITY, MI C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kwei, GH (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA BN 0-306-45827-6 J9 FUNDMAT RES PY 1998 BP 323 EP 336 PG 14 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Materials Science GA BL25J UT WOS:000074897500017 ER PT B AU Sinha, SK Pynn, R AF Sinha, SK Pynn, R BE Billinge, SJL Thorpe, MF TI Diffuse X-ray and neutron reflection from surfaces and interfaces SO LOCAL STRUCTURE FROM DIFFRACTION SE FUNDAMENTAL MATERIALS RESEARCH LA English DT Proceedings Paper CT Conference on Local Structure from Diffraction CY AUG 10-13, 1997 CL TRAVERSE CITY, MI C1 Argonne Natl Lab, Expt Facil Div, Argonne, IL 60439 USA. RP Sinha, SK (reprint author), Argonne Natl Lab, Expt Facil Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 1 U2 3 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA BN 0-306-45827-6 J9 FUNDMAT RES PY 1998 BP 351 EP 373 PG 23 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Materials Science GA BL25J UT WOS:000074897500019 ER PT S AU Karnowski, TP Gleason, SS Tobin, KW AF Karnowski, TP Gleason, SS Tobin, KW BE Rao, AR Chang, N TI Fuzzy logic connectivity in semiconductor defect clustering SO MACHINE VISION APPLICATIONS IN INDUSTRIAL INSPECTION VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Machine Vision Applications in Industrial Inspection VI CY JAN 27, 1998 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, Soc Photo Opt Instrumentat Engineers DE fuzzy logic; defect clustering; semiconductor inspection AB In joining defects on semiconductor wafer maps into clusters, it is common for defects caused by different sources to overlap. Simple morphological image processing tends to either join too many unrelated defects together or not enough together. Expert semiconductor fabrication engineers have demonstrated that they can easily group clusters of defects from a common manufacturing problem source into a single signature. Capturing this thought process is ideally suited for fuzzy logic. A system of rules was developed to join disconnected clusters based on properties such as elongation, orientation, and distance. The clusters are evaluated on a pair-wise basis using the fuzzy rules and are joined or not joined based on a defuzzification and threshold. The system continuously reevaluates the clusters under consideration as their fuzzy memberships change with each joining action. The fuzzy membership functions for each pair-wise feature, the techniques used to measure the features, and methods for improving the speed of the system are all developed. Examples of the process are shown using real-world semiconductor wafer maps obtained from chip manufacturers. The algorithm is utilized in the Spatial Signature Analyzer (SSA) software, a joint development project between Oak Ridge National Lab (ORNL) and SEMATECH. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Karnowski, TP (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2746-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3306 BP 44 EP 53 DI 10.1117/12.301244 PG 10 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BK61H UT WOS:000072737000005 ER PT S AU Patek, DR Goddard, JS Karnowski, T Lamond, D Hawkins, TA AF Patek, DR Goddard, JS Karnowski, T Lamond, D Hawkins, TA BE Rao, AR Chang, N TI Rule-based inspection of printed green ceramic tape SO MACHINE VISION APPLICATIONS IN INDUSTRIAL INSPECTION VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Machine Vision Applications in Industrial Inspection VI CY JAN 27, 1998 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, Soc Photo Opt Instrumentat Engineers DE machine vision; ceramic green tape; defect inspection; referential inspection; defect specification AB A template-based vision system for the 100% inspection of printed flaws on green ceramic tape has been developed. Design goals included a requirement for the detection of flaws as small as two thousandths of an inch on parts up to 8 by 8 inches in size. The inspection engine is a Datacube, Inc., MV200 pipeline processor. As each part is inspected, four 2K by 2K pixel quadrant images are stitched together to construct a single 4K by 4K pixel image with the aid of multiple fiducials located in each quadrant. The part fiducial locations, mask image, and punched-hole position data are generated, beforehand, from CAD designs using a defect map editor (DME), a preprocessing software package developed for the PC. The DME also generates a part "defect map". Each unique structure in the printed pattern is defined as an object. Objects are grouped into user-defined categories such as die pads, contact fingers, traces, and electrolysis buses. The map is used during the runtime inspection to associate each detected defect with an object group and a particular defect specification for that group. Repeat defects are optionally tracked for up to three consecutive parts. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Patek, DR (reprint author), Oak Ridge Natl Lab, MS6011, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2746-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3306 BP 88 EP 99 DI 10.1117/12.301234 PG 12 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BK61H UT WOS:000072737000010 ER PT S AU Tobin, KW Gleason, SS Karnowski, TP AF Tobin, KW Gleason, SS Karnowski, TP BE Rao, AR Chang, N TI Adaptation of the fuzzy k-nearest neighbor classifier for manufacturing automation SO MACHINE VISION APPLICATIONS IN INDUSTRIAL INSPECTION VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Machine Vision Applications in Industrial Inspection VI CY JAN 27, 1998 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, Soc Photo Opt Instrumentat Engineers DE fuzzy classifier; fuzzy ambiguity; k-nearest neighbor; parametric optimization; industrial automation; semiconductor AB The use of supervised pattern recognition technologies for automation in the manufacturing environment requires the development of systems that are easy to train and use. Ln general, these systems attempt to emulate an inspection or measurement function typically performed by a manufacturing engineer or technician. This paper describes a self-optimizing classification system for automatic decision making in the manufacturing environment. This classification system identifies and labels unique distributions of product defects denoted as "signatures". The technique relies on encapsulating human experience through a teaching method to emulate the human response to various manufacturing situations. This has been successfully accomplished through the adaptation and extension of a feature-based, fuzzy k-nearest neighbor (k-NN) classifier that has been implemented in a pair-wise fashion. The classifier works with pair-wise combinations of the user-defined classes so that a significant reduction in feature space and problem complexity can be achieved. This L-NN implementation makes extensive use of hold-one-out results and fuzzy ambiguity information to optimize its performance. A semiconductor manufacturing case study will be presented. The technique uses data collected from in-line optical inspection tools to interpret and rapidly identify characteristic signatures that are uniquely associated with the manufacturing process. The system then alerts engineers to probable yield-limiting conditions that require attention. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Tobin, KW (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2746-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3306 BP 122 EP 130 PG 9 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BK61H UT WOS:000072737000013 ER PT J AU Hansen, GM Justice, MJ AF Hansen, GM Justice, MJ TI Pten, a candidate tumor suppressor gene, maps to mouse Chromosome 19 SO MAMMALIAN GENOME LA English DT Article C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Justice, MJ (reprint author), Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. FU NCI NIH HHS [R29-CA63229] NR 10 TC 7 Z9 7 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD JAN PY 1998 VL 9 IS 1 BP 88 EP 90 DI 10.1007/s003359900690 PG 3 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA YN895 UT WOS:000071219500022 PM 9434957 ER PT S AU Glendenning, NK AF Glendenning, NK BE Buccheri, R vanParadijs, J Alpar, MA TI Internal constitution of neutron and strange stars SO MANY FACES OF NEUTRON STARS SE NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES C, MATHEMATICAL AND PHYSICAL SCIENCES LA English DT Proceedings Paper CT NATO Advanced Study Institute on the Many Faces of Neutron Stars CY SEP 30-OCT 11, 1996 CL LIPARI, ITALY SP NATO, Adv Study Inst Program, CNR, Area Ric Palermo,, Inst Fis Cosm & Applicazioni Informat, Sci & Tech Res Council Turkey AB In the first of these two lectures I will discuss the rich constitution of neutron stars as a consequence of the Pauli principle which is engaged by the dominance of gravity over the nuclear force. Three especially interesting phenomena are discussed in this contection-(1) a mechanism for the formation of low-mass black holes distinct in their mass-range from the black holes formed in the prompt collapse of an entire star, (2) a multi-layered crystalline structure consisting of confined hadronic matter embedded in a background of deconfined quark matter (or vice versa) which occupies a many kilometer thick inner region, and (3) a clean and pronounced signal of the formation of quark matter in the interior of neutron stars. In the second lecture I will discuss the strange matter hypothesis, its viability as well as its consequences for compact stars and a new family of white dwarfs with dense nuclear matter central regions some orders of magnitude greater than in ordinary white dwarfs. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Glendenning, NK (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0258-2023 BN 0-7923-5194-0 J9 NATO ADV SCI I C-MAT PY 1998 VL 515 BP 15 EP 48 PG 34 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL82L UT WOS:000076838700002 ER PT J AU Timmermans, KR van Leeuwe, MA de Jong, JTM McKay, RML Nolting, RF Witte, HJ van Ooyen, J Swagerman, MJW Kloosterhuis, H de Baar, HJW AF Timmermans, KR van Leeuwe, MA de Jong, JTM McKay, RML Nolting, RF Witte, HJ van Ooyen, J Swagerman, MJW Kloosterhuis, H de Baar, HJW TI Iron stress in the Pacific region of the Southern Ocean: evidence from enrichment bioassays SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE iron stress; nitrogen assimilation; phytoplankton; flavodoxin ID SUB-ARCTIC PACIFIC; EQUATORIAL PACIFIC; PHYTOPLANKTON PHOTOSYNTHESIS; MARINE-PHYTOPLANKTON; LIMITING NUTRIENT; TRACE-METALS; GROWTH-RATES; SCOTIA SEAS; LIMITATION; PLANKTON AB The effect of iron on phytoplankton physiology in a scarcely investigated part of the Pacific region of the Southern Ocean was studied during an expedition aboard RV 'Polarstern'. Physiological effects of iron enrichments were studied during short-term bottle experiments (72 h) in high-nutrient, low-chlorophyll (HNLC) water samples. Throughout the expedition (March to May 1995), surface water nitrate concentrations were high (21 to 27 mu M) and surface water silicate concentrations varied considerably north (<3.5 mu M) and south (>13 mu M) of the Polar Front, whereas low chlorophyll a concentrations (<0.2 Pg l(-1)) were measured in the research area. Small-sized cells (<5 mu m) dominated the phytoplankton community; diatoms were observed only occasionally north of the Polar Front. Total phytoplankton numbers, as determined by now cytometry, ranged from 1500 to 8000 cells ml(-1). Ambient dissolved iron concentrations in the experimental area were low and ranged from 0.1 to 0.4 nM in surface waters. In the experimental series, indications of iron stress in the indigenous phytoplankton assemblage were found. Whereas the species composition remained virtually unaltered upon addition of 2 nM iron, significant increases in nitrate uptake and enhanced nitrate reductase activities were observed within 32 h after the start of the experiments. Ammonium uptake, which prevailed over nitrate uptake, remained unaltered by the iron additions. In addition to the physiological effects, a molecular marker of iron stress, flavodoxin, was detected in phytoplankton protein extracts collected after 72 h of incubation. Irrespective of iron deficiency, silicate concentrations in the northern part of the research area were likely below half-saturation values for growth for diatoms and thereby likely prevented diatom blooms. The results of this study indicate that the nano-phytoplankton in the Pacific region of the Southern Ocean are iron stressed; upon iron enrichment, a physiological stimulation is observed. Our results support a lack of iron as one of the causes of HNLC conditions in this region. C1 Netherlands Inst Sea Res, NIOZ, Dept Marine Chem & Geol, NL-1790 AB Den Burg, Netherlands. Netherlands Inst Sea Res, NIOZ, Dept Biol Oceanog, NL-1790 AB Den Burg, Netherlands. Brookhaven Natl Lab, Dept Appl Sci, Div Oceanog & Atmospher Sci, Upton, NY 11973 USA. RP Timmermans, KR (reprint author), Netherlands Inst Sea Res, NIOZ, Dept Marine Chem & Geol, POB 59, NL-1790 AB Den Burg, Netherlands. EM klaas@nioz.nl RI de Jong, Jeroen/F-3190-2011; OI McKay, Robert/0000-0003-2723-5371 NR 62 TC 75 Z9 81 U1 0 U2 9 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 1998 VL 166 BP 27 EP 41 DI 10.3354/meps166027 PG 15 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA ZW639 UT WOS:000074431800003 ER PT S AU Peterson, KA Tangyunyong, P Pimentel, AA AF Peterson, KA Tangyunyong, P Pimentel, AA BE Friedrich, CR Vladimirsky, Y TI Failure analysis of surface-micromachined microengines SO MATERIALS AND DEVICE CHARACTERIZATION IN MICROMACHINING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Materials and Device Characterization in Micromachining CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE MEMS; microengine; failure analysis; wear debris; focused ion beam; voltage contrast; scanning electron microscope AB Microelectronic failure analysis (FA) has been an integral part of the development of state-of-the-art integrated circuits. FA of MicroElectroMechanical Systems (MEMS) is moving. from its infancy to assume an important role in the successful design, fabrication, performance and reliability analysis for this new technology. In previous work(1), we focused on the application of several techniques developed for integrated circuit analysis to an earlier version of a surface micromachined microengine fabricated at Sandia. Recently, we have identified important new failure modes in binary counters that incorporate a newer design of the microengine, using a subset of integrated circuit failure analysis techniques including optical microscopy, focused ion beam (FIB) techniques, atomic force microscopy (AFM), and scanning electron microscopy (SEM). The primary failure mode we have identified is directly related to visible wear on bearing surfaces. In this paper, we describe in detail the characteristics of the failure modes in binary counters. We also compare the failure characteristics with those of an earlier version of the microengine. C1 Sandia Natl Labs, Elect Qual Reliabil Ctr, Albuquerque, NM 87185 USA. RP Peterson, KA (reprint author), Sandia Natl Labs, Elect Qual Reliabil Ctr, M-S 1081,POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 14 Z9 14 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2971-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3512 BP 190 EP 200 DI 10.1117/12.324056 PG 11 WC Engineering, Multidisciplinary; Microscopy; Physics, Applied SC Engineering; Microscopy; Physics GA BL77N UT WOS:000076704600020 ER PT S AU Tanner, DM Peterson, KA Irwin, LW Tangyunyong, P Miller, WM Eaton, WP Smith, NF Rodgers, MS AF Tanner, DM Peterson, KA Irwin, LW Tangyunyong, P Miller, WM Eaton, WP Smith, NF Rodgers, MS BE Friedrich, CR Vladimirsky, Y TI Linkage design effect on the reliability of surface micromachined microengines driving a load SO MATERIALS AND DEVICE CHARACTERIZATION IN MICROMACHINING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Materials and Device Characterization in Micromachining CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE micro-mechanical component reliability; micromachine reliability; failure in micromachines; MEMS reliability AB The reliability of microengines is a function of the design of the mechanical linkage used to connect the electrostatic actuator to the drive. We have completed a series of reliability stress tests on surface micromachined microengines driving an inertial load. In these experiments, we used microengines that had pin mechanisms with guides connecting the drive arms to the electrostatic actuators. Comparing this data to previous results(1) using flexure linkages revealed that the pin linkage design was less reliable. The devices were stressed to failure at eight frequencies, both above and below the measured resonance frequency of the microengine. Significant amounts of wear debris were observed both around the hub and pin joint of the drive gear. Additionally, wear tracks were observed in the area where the moving shuttle rubbed against the guides of the pin linkage. At each frequency, we analyzed the statistical data yielding a lifetime (t(50)) for median cycles to failure and sigma, the shape parameter of the distribution. A model was developed to describe the failure data based on fundamental wear mechanisms and forces exhibited in mechanical resonant systems. The comparison to the model will be discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Tanner, DM (reprint author), Sandia Natl Labs, POB 5800,MS 1081, Albuquerque, NM 87185 USA. NR 0 TC 10 Z9 10 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2971-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3512 BP 215 EP 226 DI 10.1117/12.324060 PG 12 WC Engineering, Multidisciplinary; Microscopy; Physics, Applied SC Engineering; Microscopy; Physics GA BL77N UT WOS:000076704600023 ER PT S AU de Boer, MP Redmond, JM Michalske, TA AF de Boer, MP Redmond, JM Michalske, TA BE Friedrich, CR Vladimirsky, Y TI A hinged-pad test structure for sliding friction measurement in micromachining SO MATERIALS AND DEVICE CHARACTERIZATION IN MICROMACHINING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Materials and Device Characterization in Micromachining CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE sliding friction; test structure design; interferometric measurement; numerical simulation AB We describe the design, modeling, fabrication and initial testing of a new test structure for friction measurement in MEMS. The device consists of a cantilevered forked beam and a friction pad attached via a hinge. Compared to previous test structures, the proposed structure can measure friction over much larger pressure ranges, yet occupies one hundred times less area. The placement of the hinge is crucial to obtaining a well-known and constant pressure distribution in the device. Static deflections on the device were measured and modeled numerically. Preliminary results indicate that friction pad slip is sensitive to friction pad normal force. C1 Sandia Natl Labs, Dept 1725, Albuquerque, NM 87185 USA. RP de Boer, MP (reprint author), Sandia Natl Labs, Dept 1725, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 23 Z9 23 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2971-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3512 BP 241 EP 250 DI 10.1117/12.324066 PG 10 WC Engineering, Multidisciplinary; Microscopy; Physics, Applied SC Engineering; Microscopy; Physics GA BL77N UT WOS:000076704600026 ER PT S AU Tan, MX Bankert, MA Griffiths, SK Ting, AL Boehme, DR Wilson, S Balser, LM AF Tan, MX Bankert, MA Griffiths, SK Ting, AL Boehme, DR Wilson, S Balser, LM BE Friedrich, CR Vladimirsky, Y TI PMMA development studies using various synchrotron sources and exposure conditions SO MATERIALS AND DEVICE CHARACTERIZATION IN MICROMACHINING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Materials and Device Characterization in Micromachining CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE LIGA; PMMA; development rate; synchrotron AB PMMA has been the primary resist used in synchrotron exposures for micro-machined parts fabricated by the LIGA process. Because development of this resist directly influences both tolerance's and surface finish of completed LIGA structures, it is important to have a good quantitative understanding of PMMA development as a function of the absorbed dose, as well as both the exposure and development conditions. The various synchrotron sources used for LIGA fabrication vary widely in beam energy and flux, and these variations would be expected to influence development rates. Here we present a simple method to measure PMMA development rate over a moderate range of doses using only a single exposure at the synchrotron source. By employing several exposures, this method allows ready determination of development rates over a wide range of exposure and development conditions. Results are presented for the kinetics of PMMA development over a range of development temperatures, absorbed doses, dose rates and sample ages for exposures performed at three major x-ray sources in the United States. C1 Sandia Natl Labs, Dept Mat Proc, Livermore, CA 94551 USA. RP Tan, MX (reprint author), Sandia Natl Labs, Dept Mat Proc, MS 9405,POB 969, Livermore, CA 94551 USA. NR 0 TC 11 Z9 12 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2971-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3512 BP 262 EP 270 DI 10.1117/12.324068 PG 9 WC Engineering, Multidisciplinary; Microscopy; Physics, Applied SC Engineering; Microscopy; Physics GA BL77N UT WOS:000076704600028 ER PT S AU Staple, BD Watts, HA Dyck, C Griego, AP Hewlett, FW Smith, JH AF Staple, BD Watts, HA Dyck, C Griego, AP Hewlett, FW Smith, JH BE Friedrich, CR Vladimirsky, Y TI SPICE Level 3 and BSIM3v3.1 characterization of monolithic integrated CMOS-MEMS devices SO MATERIALS AND DEVICE CHARACTERIZATION IN MICROMACHINING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Materials and Device Characterization in Micromachining CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE micromechanics; CMOS; CMP; intelligent micromachines; spice models; SPICE level 3; BSIM3v3.1 AB The monolithic integration of MicroElectroMechanical Systems (MEMS) with the driving, controlling, and signal processing electronics promises to improve the performance of micromechanical devices as well as lower their manufacturing, packaging, and instrumentation costs. Key to this integration is the proper interleaving, combining, and customizing of the manufacturing processes to produce functional integrated micromechanical devices with electronics. We have developed a MEMS-first monolothic integrated process that first seals the micromechanical. devices in a planarized trench and then builds the electronics in a conventional CMOS process. To date, most of the research published on this technology has focused on the performance characteristics of the mechanical portion of the devices, with little information on the attributes of the accompanying electronics. This work attempts to reduce this information void by presenting the results of SPICE Level 3 and BSIM3v3.1 model parameters extracted for the CMOS portion of the MEMS-first process. Transistor-level simulations of MOSFET current, capacitance, output resistance, and transconductance versus voltage using the extracted model parameters closely match the measured data. Moreover, in model validation efforts, circuit-level simulation values for the average gate propagation delay in a 101-stage ring oscillator are within 13-18% of the measured data. These results establish the following: (1) the MEMS-first approach produces functional CMOS devices integrated on a single chip with MEMS devices and (2) the devices manufactured in the approach have excellent transistor characteristics. Thus, the MEMS-first approach renders a solid technology foundation for customers designing in the technology. C1 Sandia Natl Labs, Intelligent Micromachines Dept, Albuquerque, NM 87185 USA. RP Staple, BD (reprint author), Sandia Natl Labs, Intelligent Micromachines Dept, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2971-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3512 BP 410 EP 420 DI 10.1117/12.324085 PG 11 WC Engineering, Multidisciplinary; Microscopy; Physics, Applied SC Engineering; Microscopy; Physics GA BL77N UT WOS:000076704600043 ER PT S AU Diener, J Ben-Chorin, M Kovalev, DI Polisski, G Koch, F AF Diener, J Ben-Chorin, M Kovalev, DI Polisski, G Koch, F BE Polman, A Coffa, S Soref, R TI The oxidation behavior of silicon nanocrystals in the submonolayer region SO MATERIALS AND DEVICES FOR SILICON-BASED OPTOELECTRONICS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials and Devices for Silicon-Based Optoelectronics, at the 1997 MRS Fall Meeting CY DEC 01-03, 1997 CL BOSTON, MA SP Mat Res Soc, Italian CNR, SGS Thomson Microelectr, Texas Instruments AB Fourier transform infrared spectroscopy is used to determine the time evolution of oxygen incorporation onto the surface of silicon nanocrystals. Oxygen concentrations up to one monolayer are investigated. The temporal progress of surface oxidation of Si nanocrystals in porous silicon shows a linear dependence on the square root of the oxidation time. This is similar to the oxidation of hulk Si and mesoporous silicon. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Phys, Div Mat Sci, Berkeley, CA 94720 USA. RP Diener, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Phys, Div Mat Sci, Berkeley, CA 94720 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-391-6 J9 MATER RES SOC SYMP P PY 1998 VL 486 BP 261 EP 266 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Optics SC Engineering; Materials Science; Optics GA BL33A UT WOS:000075187000035 ER PT J AU O'Dell, JS McKechnie, TN Hanafee, JE AF O'Dell, JS McKechnie, TN Hanafee, JE TI Laser processing of thermal sprayed beryllium SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article AB The feasibility of using laser processing techniques to consolidate thermal sprayed beryllium deposits has been investigated. During these experiments both continuous wave CO2 and pulsed Nd-YAG lasers have been used to consolidate inert plasma sprayed and vacuum plasma sprayed beryllium deposits. Density of as-sprayed beryllium has been increased from <90% of theoretical to 100% through laser consolidation. Also, critical issues such as depth of consolidation and key processing parameters have been identified. A metallurgical analysis of these results is presented. C1 Plant Proc Inc, Huntsville, AL 35811 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 1998 VL 13 IS 2 BP 213 EP 227 PG 15 WC Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA ZL963 UT WOS:000073491100004 ER PT J AU Vo, NV Collings, EW Willis, JO Peterson, DE Liu, HK Dou, SX AF Vo, NV Collings, EW Willis, JO Peterson, DE Liu, HK Dou, SX TI Fabrication and characterization of high-T-c superconducting continuous-tube-forming/filling Bi(Pb)-2223/Ag composites and coils SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article ID JELLY-ROLL PROCESS; BI-(PB)-SR-CA-CU-O TAPES; ELECTRICAL-TRANSPORT; SINTERING PERIODS; PHASE-FORMATION; OXIDE TAPES; GROWTH; WIRES; IRREVERSIBILITY; MICROSTRUCTURE AB 'Sausaging,' 'blistering,' 'edge-cracking,' and other processing related problems are one of the major concerns facing all producers of high temperature superconducting composite conductors. These processing phenomena normally occur in composites prepared from the conventional powder-in-tube (PIT) technique. A manufacturing process that enables the production of long and truly continuous, uniform superconducting wires and tapes is the method of continuous-tube-forming/filling (CTFF). This method has been devised to minimize processing time and cost, as well as reducing ail processing related defects in ceramic composites to a minimum. The feasibility of the process has been shown using (Bi Pb)(2)Sr2Ca2Cu3O10 powder and silver sheath. Practicality has been demonstrated through the design and fabrication of double-pancake coils. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. Ohio State Univ, Dept Mat Sci & Engn, Appl Superconduct & Magnetism Labs, Columbus, OH 43201 USA. Univ Wollongong, Inst Mat Technol & Mfg, Ctr Superconducting & Elect Mat, Wollongong, NSW 2522, Australia. RI Gupta, Vishnu/B-9839-2009; Dou, Shi Xue/D-5179-2012; ayyadevara, rajaram/D-1572-2009; Liu, Hua/G-1349-2012 OI Dou, Shi Xue/0000-0003-3824-7693; Liu, Hua/0000-0002-0253-647X NR 42 TC 0 Z9 0 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 1998 VL 13 IS 3 BP 337 EP 357 DI 10.1080/10426919808935253 PG 21 WC Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA ZZ368 UT WOS:000074722400001 ER PT J AU Janney, MA Ren, WJ Kirby, GH Nunn, SD Viswanathan, S AF Janney, MA Ren, WJ Kirby, GH Nunn, SD Viswanathan, S TI Gelcast tooling: Net shape casting and green machining SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article AB Gelcasting is an advanced powder forming process. It is most commonly used to form ceramic or metal powders into complex, near-net shapes. Turbine rotors, gears, nozzles, and crucibles have been successfully gelcast in silicon nitride, alumina, nickel-based superalloy, and several steels. Gelcasting can also be used to make blanks that can be green machined to near-net shape and then high fired. Green machining has been successfully applied to both ceramic and metal gelcast blanks. Recently, we have used gelcasting to make tooling for metal casting applications. Most of the work has centered on H13 tool steel. We have demonstrated an ability to gelcast and sinter H13 to near net shape for metal casting tooling. We have also been successful in green machining gelcast blanks using a three-axis CNC milling machine. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. NR 10 TC 19 Z9 24 U1 3 U2 6 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 1998 VL 13 IS 3 BP 389 EP 403 DI 10.1080/10426919808935256 PG 15 WC Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA ZZ368 UT WOS:000074722400004 ER PT J AU Milewski, JO Thoma, DJ Fonseca, JC Lewis, GK AF Milewski, JO Thoma, DJ Fonseca, JC Lewis, GK TI Development of a near net shape processing method for rhenium using directed light fabrication SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article AB Directed Light Fabrication (DLF) is a direct metal deposition process that fuses gas delivered powder, in the focal zone of a high powered laser beam to form fully fused near net shaped components. The near net shape processing of rhenium and refractory metals is currently in development and may offer significant cost savings compared with conventional processing. A fully associative 3D design through manufacturing model is presented for the application of DLF for the fabrication of a near net shaped nozzle part. This study describes the ability to move from a parametric 3D model integrated into a manufacturing model, creating a control file which can run on the DLF machine to produce a near net shaped metal component. Examples of DLF deposited rhenium and iridium show a continuously solidified microstructure in rod and tube shapes. Entrapped porosity indicates the required direction for continued process development. These results demonstrate a new methodology for fabricating complex near net shaped components using rhenium. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. SyntheMet Corp, Los Alamos, NM 87545 USA. NR 10 TC 20 Z9 22 U1 1 U2 7 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 1998 VL 13 IS 5 BP 719 EP 730 DI 10.1080/10426919808935294 PG 12 WC Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 114UP UT WOS:000075627800006 ER PT S AU Anderson, IE Pecharsky, VK Ting, J Witham, C Bowman, RC AF Anderson, IE Pecharsky, VK Ting, J Witham, C Bowman, RC BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Benefits of rapid solidification processing of modified LaNi5 alloys by high pressure gas atomization for battery applications SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB A high pressure gas atomization approach to rapid solidification has been employed to investigate simplified processing of Sn modified LaNi5 powders that can be used for advanced Ni/metal hydride (Ni/MH) batteries. The current industrial practice involves casting large ingots followed by annealing and grinding and utilizes a complex and costly alloy design. This investigation is an attempt to produce powders for battery cathode fabrication that can be used in an as-atomized condition without annealing or grinding. Both Ar and He atomization gas were tried to investigate rapid solidification effects. Sn alloy additions were tested to promote subambient pressure absorption/desorption of hydrogen at ambient temperature. The resulting fine, spherical powders were subject to microstructural analysis, hydrogen gas cycling, and annealing experiments to evaluate suitability for Ni/MH battery applications. The results demonstrate that a brief anneal is required to homogenize the as-solidified microstructure of both Ar and He atomized powders and to achieve a suitable hydrogen absorption behavior. The Sn addition also appears to suppress cracking during hydrogen gas phase cycling in particles smaller than about 25 mu m. These results suggest that direct powder processing of a LaNi5-xSnx alloy has potential application in rechargeable Ni/MH batteries. C1 US DOE, Ames Lab, Ames, IA 50011 USA. RP Anderson, IE (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. OI Bowman, Robert/0000-0002-2114-1713 NR 0 TC 1 Z9 1 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 37 EP 42 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200004 ER PT S AU Biner, SB AF Biner, SB BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Variation of stresses ahead of the internal cracks in ReNi5, powders during hydrogen charging and discharging cycles SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB In this study, the evolution of the stress-states ahead of the penny shaped internal cracks in both spherical and disk shared ReNi5 particles during hydrogen charging and discharging cycles were investigated using coupled diffusion/deformation FEM analyses. The results indicate that large tensile stresses, on the order of 20-50% of the modulus of elasticity, develop in the particles. The disk shaped particles, in addition to having faster charging/discharging cycles, may offer better resistance to fracture than the spherical particles. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Biner, SB (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 51 EP 56 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200006 ER PT S AU Wolverton, C Zunger, A AF Wolverton, C Zunger, A BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI First-principles theory of cation and intercalation ordering in LixCoO2 SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB Several types of cation- and vacancy-ordering exist in the LixCoO2 battery material. The ordering patterns are of interest due to the fact that they can control the voltage in rechargeable Li batteries. We present a first-principles total energy theory which can predict both cation-and vacancy-ordering patterns at both zero and finite temperatures. Also, by calculating the energetics of the Li intercalation reaction, this theory can provide first-principles predictions of battery voltages of LixCoO2/Li cells. Our calculations allow us to search the entire configurational space to predict the lowest-energy ground state structures, search for large voltage cathodes, explore metastable low-energy states, and extend our calculations to finite temperatures, thereby searching for order-disorder transitions and states of partial disorder. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Wolverton, C (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Wolverton, Christopher/B-7542-2009 NR 0 TC 0 Z9 0 U1 0 U2 4 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 77 EP 88 PG 12 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200009 ER PT S AU Sandi, G Gerald, RE Scanlon, LG Carrado, KA Winans, RE AF Sandi, G Gerald, RE Scanlon, LG Carrado, KA Winans, RE BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Computational, electrochemical and Li-7 NMR studies of lithiated disordered carbons electrodes in lithium ion cells SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB Disordered carbons that deliver high reversible capacity in electrochemical cells have been synthesized by using inorganic clays as templates to control the pore size and the surface area. The capacities obtained were much higher than those calculated if the resultant carbon had a graphitic-like structure. Computational chemistry was used to investigate the nature of lithium bonding in a carbon lattice unlike graphite. The lithium intercalated fullenere Li-n-C-60 was used as a model for our (nongraphitic) disordered carbon lattice. A dilithium-C-60 system with a charge and multiplicity of (0,1) and a trilithium-C-60 system with a charge and multiplicity of (0,4) were investigated. The spatial distribution of lithium ions in an electrochemical cell containing this novel disordered carbon material was investigated in situ by Li-7 NMR using an electrochemical cell that was incorporated into a toroid cavity nuclear magnetic resonance (NMR) imager. The concentration of solvated Li+ ions in the carbon anode appears to be larger than in the bulk electrolyte, is substantially lower near the copper/carbon interface, and does not change with cell charging. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Sandi, G (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 8 Z9 8 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 95 EP 100 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200011 ER PT S AU Cygan, RT Westrich, HR Doughty, DH AF Cygan, RT Westrich, HR Doughty, DH BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Molecular dynamics study of lithium diffusion in lithium-manganese spinel cathode materials SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB A series of molecular dynamics computer simulations of the self-diffusion of lithium in pure and several doped lithium-manganese spinel materials has been completed. The theoretical approach is part of an effort to understand the mechanisms and rates of lithium diffusion, and to evaluate the structural control of the cathode materials upon lithium intercalation (charge-discharge) process. The molecular dynamics approach employs a fully ionic forcefield that accounts for electrostatic, repulsive, and dispersion interactions among all ions. A reference unit cell comprised of 56 ions (Li8Mn83+Mn84+O32) is used to perform the simulations under constant volume and constant pressure constraints. All atomic positions are allowed to vary during the simulation. Simulations were completed for the undoped and doped LiMn2O4, at Various levels of lithium content (based on the number of lithium ions per unit cell and manganese oxidation state). The molecular dynamics results indicate an activation energy of approximately 97 kJ/mole for self-diffusion of lithium in the undoped material. Lithium ion trajectories from the simulations provide diffusion coefficients that decrease by a factor of ten as the cathode accumulates lithium ions during discharge. Molecular dynamics results for the doped spinel suggest a decrease in the diffusion rate with increasing dopant ion. C1 Sandia Natl Labs, Dept Geochem, Albuquerque, NM 87185 USA. RP Cygan, RT (reprint author), Sandia Natl Labs, Dept Geochem, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 3 Z9 3 U1 2 U2 4 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 109 EP 114 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200013 ER PT S AU Benedek, R Thackeray, MM Yang, LH AF Benedek, R Thackeray, MM Yang, LH BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Structure and electrochemical potential simulation for the cathode material Li1+xV3O8 SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB The structure and electrochemical potential of monoclinic Li1+xV3O8 were calculated within the local-density-functional-theory framework by use of plane-wave-pseudopotential methods. Special attention was given to the compositions 1+x=1.2 and 1+x=4, for which x-ray diffraction structure refinements are available. The calculated low-energy configuration for 1+x=4 is consistent with the three Li sites identified in x-ray diffraction measurements and predicts the position of the unobserved Li. The location of the tetrahedrally coordinated Li in the calculated low-energy configuration for 1+x=1.5 is consistent with the structure measured by x-ray diffraction for Li1.2V3O8. Calculations were also performed for the two monoclinic phases at intermediate Li compositions, for which no structural information is available. Calculations at these compositions are based on hypothetical Li configurations suggested by the ordering of vacancy energies for Li4V3O8 and tetrahedral site energies in Li1.5V3O8. The internal energy curves for the two phrases cross near 1+x=3. Predicted electrochemical potential curves agree well with experiment. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Benedek, R (reprint author), Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. NR 0 TC 2 Z9 2 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 115 EP 120 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200014 ER PT S AU Jankowski, AF Morse, JD AF Jankowski, AF Morse, JD BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Thin film synthesis of novel electrode materials for solid-oxide fuel cells SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB Electrode materials for solid-oxide fuel cells are developed using sputter deposition. A thin film anode is formed by co-deposition of nickel and yttria-stabilized zirconia. This approach is suitable for composition grading and the provision of a mixed-conducting interfacial layer to the electrolyte layer. Similarly, synthesis of a thin film cathode proceeds by co-deposition of silver and yttria-stabilized zirconia. The sputter deposition of a thin film solid-oxide fuel cell is next demonstrated. The thin film fuel cell microstructure is examined using scanning electron microscopy whereas the cell perfomance is characterized through current-voltage measurement and corresponding impedance spectroscopy. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Jankowski, AF (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 0 TC 7 Z9 7 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 155 EP 158 PG 4 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200019 ER PT S AU Ma, B Balachandran, U Hodges, JP Jorgensen, JD Miller, DJ Richardson, JW AF Ma, B Balachandran, U Hodges, JP Jorgensen, JD Miller, DJ Richardson, JW BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Phase stability of the mixed-conducting Sr-Fe-Co-O system SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB Mixed-conducting ceramic oxides have potential uses in high-temperature electrochemical applications such as solid oxide fuel cells, batteries, sensors, and oxygen-permeable membranes. The Sr-Fe-Co-O system combines high electronic/ionic conductivity with appreciable oxygen permeability at elevated temperatures. Dense ceramic membranes made of this material can be used to separate high-purity oxygen from air without the need for external electrical circuitry, or to partially oxidize methane to produce syngas. Samples of Sr2Fe3-xCoxOy (with x = 0, 0.6, 1.0, and 1.4) were prepared by solid-state reaction method in atmospheres with various oxygen partial pressures (pO(2)) and were characterized by X-ray diffraction, scanning electron microscopy, and electrical conductivity testing. Phase components of the sample are dependent on cobalt concentration and pO(2). Electrical conductivity increases with increasing temperature and cobalt content in the material. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Ma, B (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Hodges, Jason/K-1421-2013; Ma, Beihai/I-1674-2013 OI Ma, Beihai/0000-0003-3557-2773 NR 0 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 167 EP 172 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200021 ER PT S AU Hodges, JP Jorgensen, JD Miller, DJ Ma, B Balachandran, U Richardson, JW AF Hodges, JP Jorgensen, JD Miller, DJ Ma, B Balachandran, U Richardson, JW BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Crystal structures of mixed-conducting oxides present in the Sr-Fe-Co-O system SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB The potential applications of mixed-conducting ceramic oxides include solid-oxide fuel cells, rechargeable batteries, gas sensors and oxygen-permeable membranes. Several perovskite-derived mixed Sr-Fe-Co oxides show not only high electrical-conductivity but also appreciable oxygen-permeability at elevated temperatures. For example, dense ceramic membranes of SrFeCo0.5O3-delta can be used to separate oxygen from air without the need for external electrical circuitry. The separated oxygen can be directly used for the partial oxidation of methane to produce syngas. Quantitative phase analysis of the SrFeCo0.5O3-delta material has revealed that it is predominantly composed of two Sr-Fe-Co-O systems, Sr4Fe6-xCoxO13 and SrFe1-xCoxO3-delta. Here we report preliminary structural findings on the SrFe1-xCoxO3-delta (0 less than or equal to x less than or equal to 0.3) system. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Hodges, JP (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Hodges, Jason/K-1421-2013; Ma, Beihai/I-1674-2013 OI Ma, Beihai/0000-0003-3557-2773 NR 0 TC 3 Z9 3 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 173 EP 178 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200022 ER PT S AU Besmann, TM Klett, JW Burchell, TD AF Besmann, TM Klett, JW Burchell, TD BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Carbon composite for a PEM fuel cell bipolar plate SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB The current major cost component for proton exchange membrane fuel cells is the bipolar plate. An option being explored for replacing the current, nominal machined graphite component is a molded carbon fiber material. One face and the volume of the component will be left porous, while the opposite surface and sides are hermetically sealed via chemical vapor infiltration of carbon. This paper will address initial work on the concept. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Besmann, TM (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Burchell, Tim/E-6566-2017; Klett, James/E-6860-2017 OI Burchell, Tim/0000-0003-1436-1192; Klett, James/0000-0002-2553-9649 NR 0 TC 12 Z9 12 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 243 EP 248 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200033 ER PT S AU Rodriguez, MA Ingersoll, D Doughty, DH AF Rodriguez, MA Ingersoll, D Doughty, DH BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI In-situ X-ray characterization of LiMn2O4: A comparison of structural and electrochemical behavior SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB LixMn2O4 materials are of considerable interest in battery research and development. The crystal structure of this material can significantly affect the electrochemical performance. The ability to monitor the changes of the crystal structure during use, that is during electrochemical cycling, would prove useful to verify these types of structural changes. We report in-situ XRD measurements of LiMn2O4 cathodes with the use of an electrochemical cell designed for in-situ X-ray analysis. Cells prepared using this cell design snow investigation of the changes in the LiMn2O4 structure during charge and discharge. We describe the variation in lattice parameters along the voltage plateaus and consider the structural changes in terms of the electrochemical results on each cell. Kinetic effects of LiMn2O4 phase changes are also addressed. Applications of the in-situ cell to other compounds such as LiCoO2 cathodes and carbon anodes are presented as well. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Rodriguez, MA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 6 Z9 6 U1 1 U2 5 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 275 EP 285 PG 11 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200037 ER PT S AU Ginley, DS Perkins, JD McGraw, JM Parilla, PA Fu, ML Rogers, CT AF Ginley, DS Perkins, JD McGraw, JM Parilla, PA Fu, ML Rogers, CT BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI LiCoO2 thin films grown by pulsed laser deposition on low cost substrates SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB We report on the use of pulsed laser depositon (PLD) to grow thin films of LiCoO2 on a number of low cost substrates including SnO2 coated Upilex, stainless steel and SnO2 coated glass. Highly textured (001) films grown on CVD deposited SnO2 films on 7059 glass, were obtained at 200 to 500 mTorr O-2 and a temperature of 500 C. Similar texture was not obtained on the stainless or Upilex however dense films from crystalline to amorphous were obtained. The films were characterized by x-ray diffraction and Raman spectroscopy. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ginley, DS (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 0 TC 16 Z9 16 U1 0 U2 4 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 293 EP 302 PG 10 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200039 ER PT S AU Perkins, JD Fu, ML Trickett, DM McGraw, JM Ciszek, TF Parilla, PA Rogers, CT Ginley, DS AF Perkins, JD Fu, ML Trickett, DM McGraw, JM Ciszek, TF Parilla, PA Rogers, CT Ginley, DS BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Raman scattering in LiCoO2 single crystals and thin films SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB We report Raman scattering measurements for uniaxially textured and randomly oriented polycrystalline LiCoO2 thin films as well as for LiCoO2 and LiCo0.4Al0.6O2 single crystals. For both the crystalline LiCoO2 thin film samples and the single crystal LiCoO2 samples, well defined phonon modes are observed at Raman shifts of 486 cm(-1) and 596 cm(-1) corresponding to the expected E-g and A(1g) modes of the layered LiCoO2 crystal structure with R (3) over bar m symmetry. Upon Al substitution for Co in LiCoO2, the two phonon modes appear to shift to higher energy, but further work is needed to clarify this point. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Perkins, JD (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 0 TC 9 Z9 9 U1 0 U2 12 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 329 EP 334 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200044 ER PT S AU Zhang, JG Liu, P Tracy, CE Benson, DK Turner, JA AF Zhang, JG Liu, P Tracy, CE Benson, DK Turner, JA BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI High performance vanadium oxide thin film electrodes for rechargeable lithium batteries SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB Plasma Enhanced Chemical Vapor Deposition (PECVD) was used to prepare vanadium oxide thin films as cathodes for rechargeable lithium batteries. The reactants consisted of a high vapor pressure liquid source of vanadium (VOCl3) and hydrogen and oxygen gas. Deposition parameters such as the flow rates of H-2, O-2 and VOCl3, the substrate temperature and the Rf power were optimized, and high deposition rate of 11 Angstrom/s was obtained. Vanadium oxide films with high discharge capacities of up to 408 mAh/g were prepared. The films also showed a superior cycling stability between 4 and 1.5 V at a C/0.2 rate for more than 4400 cycles. The films were amorphous up to a deposition temperature of 300 degrees C, however, deposition on to substrates with textured surfaces facilitated the formation of crystalline films. We demonstrate that both the vanadium oxide material and the PECVD deposition method are very attractive for constructing thin-film rechargeable lithium batteries with high capacity and long-term cyclic stability. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Zhang, JG (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 379 EP 384 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200052 ER PT S AU Guidotti, RA Nelson, GC AF Guidotti, RA Nelson, GC BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Passive-film formation on metal substrates in 1M LiPF6/EC-DMC solutions SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB The initial irreversible capacity loss in lithium-ion cells has been attributed to passive-film formation on the carbon and graphite anodes during the first intercalation, We have examined the nature of these passive films on select metal substrates. We studied film formation on Cu, 304 stainless steel, and Mo cycled in a 1M LiPF6/ethylene carbonate (EC)-dimethyl carbonate (DMC) solution ( 1:1 v/v) over a potential range of 3 V to below 0 V. Film formation occurs readily on each of the metals and involves both solvent and salt species. The composition, thickness, and distribution of the films depends strongly on the substrate. The redox processes that occur during film formation and the potential for Li plating are highly dependent on the substrate composition. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Guidotti, RA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 469 EP 475 PG 7 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200065 ER PT S AU Zavadil, KR Guidotti, RA Even, WR AF Zavadil, KR Guidotti, RA Even, WR BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Electrochemical and spectroscopic evaluation of lithium intercalation in tailored polymethacrylonitrile carbons SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB Disordered polymethacrylonitrile (PMAN) carbon monoliths have been studied as potential tailored electrodes for lithium ion batteries. A combination of electrochemical and surface spectroscopic probes have been used to investigate irreversible loss mechanisms. Voltammetric measurements show that Li intercalates readily into the carbon at potentials 1V positive of the reversible Li potential. The coulometric efficiency rises rapidly from 50% for the first potential cycle to greater than 85% for the third cycle, indicating that solvent decomposition is a self-limiting process. Surface film composition and thickness, as measured by x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS), does not vary substantially when compared to more ordered carbon surfaces. Li+ profiles are particularly useful in discriminating between the bound states of Li at the surface of solution permeable PMAN carbons. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Zavadil, KR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 539 EP 544 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200074 ER PT S AU Tran, TD Lenz, D Kinoshita, K Droege, M AF Tran, TD Lenz, D Kinoshita, K Droege, M BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Electrochemical properties of carbon aerogel composites SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB The carbon aerogel/carbon paper composites have physical properties similar to those of monolithic carbon aerogels but do not require supercritical extraction during fabrication. The resorcinol-formaldehyde based carbon aerogel phase is intertwined between the fibers of a commercial carbon paper. The resulting composites have variable densities (0.4-0.6 g/cc), high surface areas (300-600 m(2)/g), and controllable pore sizes and pore distribution. The effects of the resorcinol-formaldehyde concentrations (50-70% w/v) and the pyrolysis temperature (600-1050 degrees C) were studied in an attempt to tailor the aerogel microstructure and properties. The composite physical properties and structure were analyzed by transmission electron microscopy and multipoint-BET analyses and related to electrochemical capacitive data in 5M KOH. These thin carbon aerogel/carbon paper composite electrodes are used in experiments with electrochemical double-layer capacitors and capacitive deionization. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. RP Tran, TD (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 607 EP 611 PG 5 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200084 ER PT S AU Even, WR Peng, LW Yang, N Guidotti, R Headley, T AF Even, WR Peng, LW Yang, N Guidotti, R Headley, T BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Intercalation of disordered, "hard" carbons SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB Disordered carbons were synthesized st 700 degrees C from methacrylonitrile-divinylbenzene precursors. The disorder, even at the free surface, was confirmed with TEM. These powdered carbons were subjected to rapid surface heating by a pulsed infrared laser. While the bulk structure remained essentially unchanged, there was substantial surface reconstruction to a depth of 0.25 mu m after heating (5.9 W average power at 10Hz, 10 ns pulse width, 1064nm wavelength). The surface ordering appears similar to the bulk microstructure of carbons isothermally annealed at 2,200 degrees C (i.e., turbostratic). Improvements were observed in first cycle irreversible loss, rate capability, and coulombic efficiencies of the reconstructed carbons, relative to the untreated carbon. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Even, WR (reprint author), Sandia Natl Labs, POB 969, Livermore, CA 94551 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 619 EP 624 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200086 ER PT S AU Wright, RB Murphy, TC Rogers, SA Sutula, RA AF Wright, RB Murphy, TC Rogers, SA Sutula, RA BE Ginley, DS Doughty, DH Scrosati, B Takamura, T Zhang, ZMJ TI Experimental electrochemical capacitor test results SO MATERIALS FOR ELECTROCHEMICAL ENERGY STORAGE AND CONVERSION II-BATTERIES, CAPACITORS AND FUEL CELLS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials for Electrochemical Energy Storage and Conversion II-Batteries, Capacitors and Fuel Cells, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc AB Various electrochemical capacitors (ultracapacitors) are being developed for hybrid vehicles as candidate power assist devices for the Partnership for a New Generation of Vehicles (PNGV) fast-response engine. The envisioned primary functions of the ultracapacitor are to level the dynamic power loads on the primary propulsion device and recover available energy From regenerative breaking during off-peak power periods. This paper will present test data from selected U.S. Department of Energy (DOE) supported ultracapacitor projects designed to meet the fast response engine requirements. This paper will address the temperature dependence of test data obtained from a set of three devices provided from Maxwell Energy Products, Inc. These devices are rated at 2300 F at 2.3 V. Constant-current, constant-power, and self-discharge testing as a function of temperature have been conducted. From these tests were determined the capacitance, equivalent series resistance, specific energy and power, and the self-discharge energy loss factor as a function of the device operating temperature. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Wright, RB (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-401-7 J9 MATER RES SOC SYMP P PY 1998 VL 496 BP 661 EP 668 PG 8 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA BL33C UT WOS:000075187200091 ER PT S AU Tong, WM Pan, LS Felter, TE Anders, S Cossy-Favre, A Stammler, T AF Tong, WM Pan, LS Felter, TE Anders, S Cossy-Favre, A Stammler, T BE Zhu, W Pan, LS Felter, TE Holland, C TI The effect of aspect ratio and sp(2)/sp(3) content on the field emission properties of carbon films grown by N-2-spiked PECVD SO MATERIALS ISSUES IN VACUUM MICROELECTRONICS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Materials-Research-Society Symposium on Materials Issues in Vacuum Microelectronics CY APR 13-16, 1998 CL SAN FRANCISCO, CA SP Mat Res Soc, Lucent Technol, Bell Lab, Candescent Technol Corp, Motorola AB We have deposited carbon films from mixtures of methane and N-2 using Plasma Enhanced Chemical Vapor Deposition. By changing the percentage of N-2 in the feed gas, we were able to produce films that have various aspect ratios and sp(2)/sp(3) contents. The film with the highest field emission contains spears of aspect ratio of 10:1. We also found that in our sp(3)-rich films, higher sp(2) content enhanced field emission. This is ascribed to improved charge transport to the field emission sites. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Tong, WM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Raoux, Simone/G-3920-2016 NR 0 TC 3 Z9 3 U1 1 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-415-7 J9 MATER RES SOC SYMP P PY 1998 VL 509 BP 155 EP 160 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA BL60C UT WOS:000075974000024 ER PT S AU Walter, KC Lee, DH He, XM Baker, NP Nastasi, M Munson, CP Scarborough, WK Tuszewski, M Wood, BP AF Walter, KC Lee, DH He, XM Baker, NP Nastasi, M Munson, CP Scarborough, WK Tuszewski, M Wood, BP BE Knystautas, EJ TI Surface modification by plasma immersion ion processing SO MATERIALS MODIFICATION BY ION IRRADIATION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Materials Modification by Ion Irradiation CY JUL 15-16, 1998 CL QUEBEC, CANADA SP SPIE Int Soc Opt Engn, Govt Canada, Govt Quebec, Greater Quebec Econ Dev Corp, INO Inst Natl Optique, Soc Innovatech Quebec Chadiere-Appalaches, Univ Laval, Quebec City, Opt Soc Amer, Flynn Rivard, Barristers & Solicitors Quebec DE tribology; coating; diamond-like carbon; boron-carbide; PIIP; PSII AB Los Alamos National Laboratory is actively researching a surface modification technique called plasma immersion ion processing(PIIP). PIIP is the latest innovation of the plasma source ion implantation (PSII) approach to surface modification. Like PSII, PIIP allows the modification of large areas (many m(2)) and non-planar surface geometries, however PIIP is primarily a coating deposition technology rather than solely an ion implantation technology. PIIP utilizes a pulsed-bias on a target to extract ions out of plasma for ion implantation (>10 kV) and coating deposition (<10 kV). Plasmas can be made by capacitive or inductive radio frequency sources or by initiating a glow discharge during each pulse of high voltage. Plasmas of hydrocarbon gases have been used to deposit adherent diamond-like carbon (DLC) coatings on a variety of ferrous and non-ferrous materials. Instead of sputter depositing interlayers to improve the adhesion of DLC, PIIP uses ion implantation tp create a graded interface between the metallic substrate and the DLC coating. Demonstrating the scaleability of PIIP, a 3 m(2) area has been simultaneously coated with an adherent DLC coating approximately 7 mu m thick. Plasmas of diborane and acetylene mixtures are being used to develop deposition processes for boron-carbide coatings. Through the use of organometallics and inorganic gases, other coatings are possible. The PIIP deposition conditions, composition and tribological properties of DLC and boron-carbide coatings will be highlighted. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Walter, KC (reprint author), Univ Calif Los Alamos Natl Lab, MS-K762, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2867-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3413 BP 156 EP 164 DI 10.1117/12.321944 PG 9 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA BL84T UT WOS:000076922700016 ER PT S AU Kang, SH Morris, JW Kim, CU AF Kang, SH Morris, JW Kim, CU BE Bravman, JC Marieb, TN Lloyd, JR Korhonen, MA TI Electromigration failure kinetics in Al alloy lines: A microstructure-based constitutive equation SO MATERIALS RELIABILITY IN MICROELECTRONICS VIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Reliability in Microelectronics VIII CY APR 13-16, 1998 CL SAN FRANCISCO, CA SP Adv Micro Devices, Aetrium, Lucent Technol, Bell Labs, IBM, Lloyd Technol Assoc, Sandia Natl Labs AB In previous work we proposed a simple constitutive equation that describes the electromigration failure kinetics in naturally passivated Al(Cu) quasi-bamboo lines. The time to failure, t(f) obeys the relation, t(f) = t(0) exp (-l/l(0)), where t(0) and l(0) are characteristic constants and I is the length of the polygranular segment that causes failure (which is ordinarily the longest polygranular segment in the line). The present paper gathers the data supporting this relation, which includes tests on lines as-patterned and annealed at low and high temperature, and examines the dependence of the factors t(0) and l(0) on current density, test temperature, line geometry, and Al2Cu precipitate distribution. The experimental data suggest that t(0) varies geometrically with j, with exponent n approximate to 2.8, and exponentially with T-1, with activation energy of similar to 0.69 eV. It also varies with the line width and the distribution of Al2Cu precipitates. On the other hand, l(0) is only weakly dependent on current density and temperature, but may vary with the ratio of line width to grain size (w/G). C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. RP Kang, SH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-422-X J9 MATER RES SOC SYMP P PY 1998 VL 516 BP 129 EP 134 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BM12L UT WOS:000077688100020 ER PT S AU Wolfer, WG Bartelt, MC Dike, JJ Hoyt, JJ Gleixner, RJ Nix, WD AF Wolfer, WG Bartelt, MC Dike, JJ Hoyt, JJ Gleixner, RJ Nix, WD BE Bravman, JC Marieb, TN Lloyd, JR Korhonen, MA TI Modeling of failure time distributions for interconnects due to stress voiding and electromigration SO MATERIALS RELIABILITY IN MICROELECTRONICS VIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Reliability in Microelectronics VIII CY APR 13-16, 1998 CL SAN FRANCISCO, CA SP Adv Micro Devices, Aetrium, Lucent Technol, Bell Labs, IBM, Lloyd Technol Assoc, Sandia Natl Labs AB A status report is given on a comprehensive modeling project aimed at predicting failure time distributions of interconnect lines. We discuss our novel approach to calculate the evolution of stresses in lines using elastic response functions. It is argued that this approach makes it possible to model the stress and damage evolution in a large ensemble of lines efficiently so that statistically meaningful failure time distributions can be generated. The elastic response functions enable us also to derive a generalized Korhonen equation which includes the effects of mass transport at remote locations. Basic features of this equation are demonstrated with a one-dimensional implementation and its results are compared with the classical Korhonen [8, 9, 10] model. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Wolfer, WG (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-422-X J9 MATER RES SOC SYMP P PY 1998 VL 516 BP 147 EP 158 PG 12 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BM12L UT WOS:000077688100022 ER PT J AU Cai, WD Smugeresky, J Lavernia, EJ AF Cai, WD Smugeresky, J Lavernia, EJ TI Low-pressure spray forming of 2024 aluminum alloy SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE 2024 aluminum alloy; microstructure; spray forming ID LIQUID DYNAMIC COMPACTION; DEPOSITION PROCESS; ATOMIZATION; MICROSTRUCTURE; TEMPERATURE; BEHAVIOR; MODEL; SI AB In this paper, a newly developed low-pressure spray forming (LPSF) technique is described, The experimental results obtained with an as-deposited 2024 aluminum alloy are reported. It is shown that the application of reduced pressure significantly decreases porosity as compared to conventionally spray-formed 2024 aluminum alloy, Moreover, the resultant microstructures are similar to those achieved with conventional spray forming. The mechanisms of porosity formation in deposited materials, obtained using both low pressure and conventional spray forming, are discussed. Gas entrapment and interstitial porosity are proposed to be the two major sources of the porosity present in the as-deposited materials. On the basis of the present study, the controlled low-pressure environment during LPSF appears to influence the droplet trajectories and the gas flow field, leading to flow-straightening effects which result in significant reduction of porosity in the deposited materials. (C) 1998 Elsevier Science S.A. C1 Univ Calif Irvine, Dept Chem Biochem Engn & Mat Sci, Irvine, CA 92697 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Lavernia, EJ (reprint author), Univ Calif Irvine, Dept Chem Biochem Engn & Mat Sci, Irvine, CA 92697 USA. NR 44 TC 17 Z9 24 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JAN PY 1998 VL 241 IS 1-2 BP 60 EP 71 DI 10.1016/S0921-5093(97)00477-2 PG 12 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA YX503 UT WOS:000072046800007 ER PT J AU Mukai, T Nieh, TG Iwasaki, H Higashi, K AF Mukai, T Nieh, TG Iwasaki, H Higashi, K TI Superplasticity in doubly extruded magnesium composite ZK60/SiC/17p SO MATERIALS SCIENCE AND TECHNOLOGY LA English DT Article ID METAL MATRIX COMPOSITE; ALLOY; FLOW; EXTRUSION AB Superplasticity in a doubly extruded magnesium based composite, ZK60 reinforced with 17 vol-%SiC particles, was investigated. The influences of strain rate on the flow stress and elongation in the composite were characterised. It was found that the composite exhibited superplasticity (elongation > 400%) at high strain sates (similar to 0.1 s(-1)). In addition, the material showed a high strain rate sensitivity of 0.5 and an activation energy of 81 kJ mol(-1) in the superplastic region. Based upon these results, it was proposed that the dominant deformation mechanism is gain boundary sliding accommodated by a grain boundary diffusion process. A comparison of the superplastic behaviour was also made between the doubly extruded and singly extruded composites. (C) 1998 The Institute of Materials. C1 Osaka Municipal Tech Res Inst, Osaka 536, Japan. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA USA. Himeji Inst Technol, Himeji, Hyogo 67122, Japan. Univ Osaka Prefecture, Sakai, Osaka 591, Japan. RP Mukai, T (reprint author), Osaka Municipal Tech Res Inst, Osaka 536, Japan. RI Nieh, Tai-Gang/G-5912-2011; Mukai, Toshiji/F-9570-2014; Totsukawa, Nobuhisa/D-2028-2017 OI Nieh, Tai-Gang/0000-0002-2814-3746; Mukai, Toshiji/0000-0002-9628-5762; NR 26 TC 35 Z9 37 U1 0 U2 5 PU INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON SW1Y 5DB, ENGLAND SN 0267-0836 J9 MATER SCI TECH SER JI Mater. Sci. Technol. PD JAN PY 1998 VL 14 IS 1 BP 32 EP 35 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YY979 UT WOS:000072207800005 ER PT S AU Meldrum, A Halden, NM AF Meldrum, A Halden, NM BE Mulder, B Schmidt, CF Vogel, V TI Fine-scale oscillatory banding in otoliths from Arctic charr (Salvelinus alpinus) and pike (Esox lucius) SO MATERIALS SCIENCE OF THE CELL SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Science of the Cell at the 1997 MRS Fall Meeting CY DEC 01-04, 1997 CL BOSTON, MA SP Whitaker Fdn, Chroma Technol, Mat Res Soc (MRS) AB Transmission electron microscopy of otoliths from the inner ear of arctic charr and pike has revealed the presence of fine banding on the scale of several nanometers. The thickness of the bands was observed to vary in different portions of the sample, and some areas were not banded. EDS analysis could not detect chemical differences within the bands, but electron diffraction showed that the crystallographic orientation of the bands is related by a lattice mismatch indicative of a twinning relationship. Previously, banding on the scale of 50 to 100 microns was observed by SEM in otoliths from arctic charr and was attributed to seasonal variations in growth. The fine-scale twinning observed in this study, however, is unlikely to be nucleated through daily variations. Electron diffraction from the pike samples shows that the material is composed of CaCO3 having the both the vaterite and aragonite structure, and hydrous CaCO3 was also observed. The interaction of the electron beam with the sample material was investigated by conducting several electron-irradiation experiments. The electron beam was observed to interact strongly with the sample and caused the precipitation of cubic CaO from the calcium carbonate matrix. Bright-field imaging showed the development of fine grained (similar to 5 nm) randomly-oriented crystallites which accumulated with increasing electron dose. These initial results suggest that the precipitation of CaO is not driven by electron-beam heating. Previously, a similar phase-change phenomenon has been observed in hydroxyapatite from dental enamel. Other Ca-bearing biominerals may therefore also be expected to be sensitive to electron irradiation. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Meldrum, A (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-394-0 J9 MATER RES SOC SYMP P PY 1998 VL 489 BP 167 EP 172 PG 6 WC Biophysics; Cell Biology SC Biophysics; Cell Biology GA BM11Z UT WOS:000077674600026 ER PT B AU Kimmel, R AF Kimmel, R BE Daehlen, M Lyche, T Schumaker, LL TI A natural geometric norm for multi-channel image processing SO MATHEMATICAL METHODS FOR CURVES AND SURFACES II SE INNOVATIONS IN APPLIED MATHEMATICS LA English DT Proceedings Paper CT International Conference on Mathematical Methods for Curves and Surfaces CY JUL 03-08, 1997 CL LILLEHAMMER, NORWAY SP SINTEF, Res Council Norway, Univ Olso AB The geometrical framework in which images are considered as surfaces is shown to be a natural selection for color image processing. The steepest descent flow associated with the first variation of the area functional is a significant selective smoothing procedure. Generally, the steepest descent flow for multi-channel variational methods smoothes the different channels of the image. The functional should capture the way the smoothing process acts on the different color channels while exploring the coupling between them. Here we justify the usage of the area norm obtained by the geometric framework, and the Beltrami steepest descent flow as its natural scale-space. We list the requirements, relate to other recent norms, and present simulation results. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Kimmel, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU VANDERBILT UNIV PRESS PI NASHVILLE PA NASHVILLE, TN 37212 USA BN 0-8265-1315-8 J9 INNOV APPL MATH PY 1998 BP 271 EP 278 PG 8 WC Computer Science, Software Engineering; Engineering, Multidisciplinary; Mathematics, Applied SC Computer Science; Engineering; Mathematics GA BL52N UT WOS:000075773000026 ER PT S AU Huang, LJ Fehler, MC Burch, CC AF Huang, LJ Fehler, MC Burch, CC BE Hassanzadeh, S TI A hybrid local Born/Rytov Fourier migration method SO MATHEMATICAL METHODS IN GEOPHYSICAL IMAGING V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Mathematical Methods in Geophysical Imaging V CY JUL 20-21, 1998 CL SAN DIEGO, CA SP SPIE DE Fourier migration; Born approximation; Rytov approximation; variable extrapolation interval; hybrid AB Two efficient Fourier migration methods termed the extended local Born Fourier (ELBF) method and the extended Rytov Fourier (ELRF) method have been developed recently for imaging complex 3D structures. They are recursive methods based on local applications of Born and Rytov approximations within each extrapolation interval. The ELBF method becomes unreliable when the lateral slowness variations are large and/or the frequency is high, while the ELRF method is reliable for such cases. However, the ELRF method is approximately 30-40% slower than the ELBF method because the ELRF method requires one more computational step where exponentials of complex numbers are calculated than the ELBF method during wave extrapolation within each extrapolation interval. We investigate the applicability condition of the ELBF method and propose an implementation scheme using variable extrapolation intervals to make the ELBF method reliable for all lateral slowness variations and frequencies. The size of the extrapolation interval depends on the lateral slowness variations within a given extrapolation region and the frequency, and consequently, the computational time of the ELBF method with variable extrapolation intervals increases with the lateral slowness variation and frequency. To take advantage of the faster computational speed of the ELBF method compared to the ELRF method and the better stability of the ELRF method compared to the ELBF method, we propose a hybrid local Born/Rytov Fourier migration method. In the hybrid method, the ELBF method is used for regions with small lateral slowness variations and/or low frequencies, otherwise, the ELRF method is used. Migrations of two synthetic datasets for complex structures using the ELBF method with variable extrapolation intervals and the hybrid method demonstrate that the quality of images obtained using these two methods is comparable to that of images obtained using the ELRF method. Comparison of computational times for migrations using different methods shows that the ELBF method with variable extrapolation intervals takes much more computational time than the ELRF method but the hybrid method saves more than 10% of the computational time required by the ELRF method. C1 Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. RP Huang, LJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Mail Stop D443, Los Alamos, NM 87545 USA. NR 0 TC 5 Z9 5 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2908-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3453 BP 14 EP 25 DI 10.1117/12.323291 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA BL81A UT WOS:000076793900002 ER PT S AU Berryman, JG Wang, HF AF Berryman, JG Wang, HF BE Hassanzadeh, S TI Double porosity modeling in elastic wave propagation for reservoir characterization SO MATHEMATICAL METHODS IN GEOPHYSICAL IMAGING V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Mathematical Methods in Geophysical Imaging V CY JUL 20-21, 1998 CL SAN DIEGO, CA SP SPIE DE seismic wave propagation; rocks with fluids; poroelasticity; double-porosity AB Phenomenological equations for the poroelastic behavior of a double porosity medium have been formulated and the coefficients in these linear equations identified. The generalization from a single porosity model increases the number of independent coefficients from three to six for an isotropic applied stress. In a quasistatic analysis, the physical interpretations are based upon considerations of extremes in both spatial and temporal scales. The limit of very short times is the one most relevant for wave propagation, and in this case both matrix porosity and fractures are expected to behave in an undrained fashion, although our analysis makes no assumptions in this regard. For the very long times more relevant for reservoir drawdown, the double porosity medium behaves as an equivalent single porosity medium. At the macroscopic spatial level, the pertinent parameters (such as the total compressibility) may be determined by appropriate field tests. At the mesoscopic scale pertinent parameters of the rock matrix can be determined directly through laboratory measurements on core, and the compressiblity can be measured for a single fracture. We show explicitly how to generalize the quasistatic results to incorporate wave propagation effects and how effects that are usually attributed to squirt flow under partially saturated conditions can be explained alternatively in terms of the double-porosity model. The result is therefore a theory that generalizes, but is completely consistent with, Blot's theory of poroelasticity and is valid for analysis of elastic wave data from highly fractured reservoirs. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Berryman, JG (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808 L-200, Livermore, CA 94551 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2908-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3453 BP 58 EP 69 DI 10.1117/12.323295 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA BL81A UT WOS:000076793900006 ER PT S AU Vogel, JS Turteltaub, KW AF Vogel, JS Turteltaub, KW BE Clifford, AJ Muller, HG TI Accelerator mass spectrometry as a bioanalytical tool for nutritional research SO MATHEMATICAL MODELLING IN EXPERIMENTAL NUTRITION SE ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY LA English DT Article; Proceedings Paper CT Conference on Mathematical Modeling in Experimental Nutrition CY AUG 17-20, 1997 CL DAVIS, CALIFORNIA SP US Natl Inst Hlth, US Natl Sci Fdn, USDA, W Human Nutr Ctr, Lawrence Livermore Natl, Ctr Accelerator Mass Spect, F Hoffman La Roche & Co Ltd, Ralston Purina, Univ California Davis, Coll Agr & Environm Sci, Univ California Davis, Coll Letters & Sci, Div Math & Phys Sci ID BIOMEDICAL APPLICATIONS; BONE-RESORPTION; AMS; AL-26; ALUMINUM; TRACER; CA-41; C-14; QUANTIFICATION; ABSORPTION AB Accelerator Mass Spectrometry is a mass spectrometric method of detecting long-lived radioisotopes without regard to their decay products or half-life. The technique is normally applied to geochronology, but is also available for bioanalytical tracing. AMS detects isotope concentrations to parts per quadrillion, quantifying labeled biochemicals to attomole levels in milligram-sized samples. Its advantages over non-isotopic and stable isotope labeling methods are reviewed and examples of analytical integrity, sensitivity, specificity, and applicability are provided. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RP Vogel, JS (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, 7000 East Ave,L-397, Livermore, CA 94551 USA. NR 41 TC 29 Z9 29 U1 0 U2 2 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0065-2598 BN 0-306-46020-3 J9 ADV EXP MED BIOL JI Adv.Exp.Med.Biol. PY 1998 VL 445 BP 397 EP 410 PG 14 WC Medicine, Research & Experimental; Nutrition & Dietetics SC Research & Experimental Medicine; Nutrition & Dietetics GA BL45M UT WOS:000075566800025 PM 9781403 ER PT S AU Brooks, JA Li, M Yang, NCY AF Brooks, JA Li, M Yang, NCY BE Cerjak, H TI Solidification behaviour and structure of Al-Cu alloy welds SO MATHEMATICAL MODELLING OF WELD PHENOMENA 4 SE MATERIALS MODELLING SERIES LA English DT Proceedings Paper CT 4th International Seminar on Numerical Analysis of Weldability CY SEP, 1997 CL SCHLO SEGGAU, AUSTRIA SP Tech Univ Graz, Inst Mat Sci & Welding Technol, Int Inst Welding, Commiss IX, Working Grp Math Modelling Weld Phenomena ID DENDRITIC GROWTH; MICROSEGREGATION AB The microsegregation behaviour of electron beam (EB) and gas tungsten are (GTA) welds of Al-Cu alloys covering a range from 0.19 to 7.74 wt% Cu were characterized for dendrite core concentrations and fraction eutectic solidification. Although a single weld speed of 12.7 mm/sec was used, some differences were observed in the segregation behaviour of the two weld types. The microsegregation behaviour was also modelled using a finite differences technique considering dendrite tip and eutectic undercooling and solid state diffusion. Fairly good agreement was observed between measured and calculated segregation behaviour although differences between the two weld types could not be completely accounted for. The concept, of dendrite tip undercooling was used to explain the formation of a single through thickness centerline grain in the higher alloy content GTA welds. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Brooks, JA (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 21 TC 0 Z9 0 U1 0 U2 2 PU INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON SW1Y 5DB, ENGLAND SN 1352-9692 BN 1-86125-060-6 J9 MAT MODELLING SER PY 1998 BP 184 EP 198 PG 15 WC Materials Science, Multidisciplinary; Mathematics, Applied; Metallurgy & Metallurgical Engineering SC Materials Science; Mathematics; Metallurgy & Metallurgical Engineering GA BN41C UT WOS:000081854900011 ER PT S AU Dike, JJ Brooks, JA Li, M AF Dike, JJ Brooks, JA Li, M BE Cerjak, H TI Comparison of failure criteria in weld solidification cracking simulations SO MATHEMATICAL MODELLING OF WELD PHENOMENA 4 SE MATERIALS MODELLING SERIES LA English DT Proceedings Paper CT 4th International Seminar on Numerical Analysis of Weldability CY SEP, 1997 CL SCHLO SEGGAU, AUSTRIA SP Tech Univ Graz, Inst Mat Sci & Welding Technol, Int Inst Welding, Commiss IX, Working Grp Math Modelling Weld Phenomena AB Finite element simulations of gas tungsten are (GTA) welds in 6061-T6 aluminum are used to examine the application of strain-based, stress-based, and void growth-based failure criteria to weld solidification cracking problems. A strain rate and temperature dependent plasticity model is coupled with a void growth damage model to predict weld solidification cracking. To examine strain-based and stress-based failure criteria, the same constitutive model is used with the damage portion of the model inactivated. Stresses and mechanical strains accumulated during solidification are recorded. Welding experiments are used to provide experimental examples of solidification cracking for comparison with the analyses. Cracking locations were observed in the experiment for different specimen geometries and welding parameters. Stresses and strains at locations in which cracks were observed experimentally are computed and compared to determine if one of these failure criteria appears to consistently predict the correct cracking location. The results of the simulations do not strongly indicate that any of the failure criteria applied here more accurately predict cracking than the others. This conclusion may largely be due to the manner in which these criteria are compared and so this should be modified. Rather than comparing results at individual elements at only a few locations on the specimens it would be more appropriate to incorporate the various failure criteria into the simulations and examine the results on a more global basis. The only criterion that was implemented into the analysis code in this manner was the void growth damage model. It performed reasonably well in predicting where along the weld and where relative to the weld centerline cracking initiates, but the propagation of the cracks relative to the weld centerline is not correct. Possible improvements to the analyses and evaluation procedures are described. C1 Sandia Natl Labs, Solid & Mat Mech Dept, Livermore, CA 94550 USA. RP Dike, JJ (reprint author), Sandia Natl Labs, Solid & Mat Mech Dept, Livermore, CA 94550 USA. NR 31 TC 2 Z9 2 U1 1 U2 1 PU INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON SW1Y 5DB, ENGLAND SN 1352-9692 BN 1-86125-060-6 J9 MAT MODELLING SER PY 1998 BP 199 EP 222 PG 24 WC Materials Science, Multidisciplinary; Mathematics, Applied; Metallurgy & Metallurgical Engineering SC Materials Science; Mathematics; Metallurgy & Metallurgical Engineering GA BN41C UT WOS:000081854900012 ER PT S AU David, SA Babu, SS Vitek, JM AF David, SA Babu, SS Vitek, JM BE Cerjak, H TI Weldability and microstructure development in nickel-base superalloys SO MATHEMATICAL MODELLING OF WELD PHENOMENA 4 SE MATERIALS MODELLING SERIES LA English DT Proceedings Paper CT 4th International Seminar on Numerical Analysis of Weldability CY SEP, 1997 CL SCHLO SEGGAU, AUSTRIA SP Tech Univ Graz, Inst Mat Sci & Welding Technol, Int Inst Welding, Commiss IX, Working Grp Math Modelling Weld Phenomena ID ATOM PROBE; CRACKING; ALLOY; WELDS AB The integrity of nickel-base superalloy single-crystal welds depends on the weld cracking tendency, weld metal dendrite selection process, stray crystal formation, and macro- and microstructure development. These phenomena have been investigated in commercial nickel-base superalloy single crystal welds. During electron beam and laser beam welding, transverse and longitudinal weld cracking occurred. However, the weld cracking tendency was reduced with preheating. Most of the dendritic growth pattern development in these welds can be explained by a geometric model. However, the welds also contained misoriented stray crystals, which were frequently associated with weld cracks. The formation of stray crystals was related to thermal and constitutional supercooling effects. Fine-scale elemental partitioning between gamma and gamma' phase was measured with atom-probe field-ion microscopy. Marked differences in partitioning characteristics in two welds were observed and are related to differences in cooling rates. In this paper, the modelling tools available to describe the above are reviewed. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP David, SA (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Babu, Sudarsanam/D-1694-2010 OI Babu, Sudarsanam/0000-0002-3531-2579 NR 21 TC 2 Z9 2 U1 0 U2 2 PU INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON SW1Y 5DB, ENGLAND SN 1352-9692 BN 1-86125-060-6 J9 MAT MODELLING SER PY 1998 BP 269 EP 289 PG 21 WC Materials Science, Multidisciplinary; Mathematics, Applied; Metallurgy & Metallurgical Engineering SC Materials Science; Mathematics; Metallurgy & Metallurgical Engineering GA BN41C UT WOS:000081854900016 ER PT S AU Vitek, JM David, SA AF Vitek, JM David, SA BE Cerjak, H TI Modelling the ferrite-austenite transformation in the heat-affected zone of stainless steel welds SO MATHEMATICAL MODELLING OF WELD PHENOMENA 4 SE MATERIALS MODELLING SERIES LA English DT Proceedings Paper CT 4th International Seminar on Numerical Analysis of Weldability CY SEP, 1997 CL SCHLO SEGGAU, AUSTRIA SP Tech Univ Graz, Inst Mat Sci & Welding Technol, Int Inst Welding, Commiss IX, Working Grp Math Modelling Weld Phenomena ID CR-NI SYSTEM; GAMMA/ALPHA/GAMMA-DIFFUSION COUPLES; ALPHA-PHASE; SOLIDIFICATION; DISSOLUTION AB The diffusion-controlled ferrite-austenite transformation in stainless steel welds was modeled. An implicit finite-difference analysis that considers multi-component diffusion was used. The model was applied to the Fe-Cr-Ni system to investigate the ferrite-austenite transformation in the heat-affected zone of stainless steel weld metal. The transformation was followed as a function of time as the heat-affected zone was subjected to thermal cycles comparable to those experienced during gas-tungsten are welding. The results showed that the transformation behaviour and the final microstructural state are very sensitive to the maximum temperature that is experienced by the heat-affected zone. For high maximum exposure temperatures (similar to 1300 degrees C), the ferrite formation that occurs at the highest temperatures is not completely offset by the reverse ferrite dissolution at lower temperatures. As a result, for high temperature exposures there is a net increase in the amount of ferrite in the microstructure. It was also found that if compositional gradients are present in the initial ferrite and austenite phases, the extent of the transformation is impacted. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Vitek, JM (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON SW1Y 5DB, ENGLAND SN 1352-9692 BN 1-86125-060-6 J9 MAT MODELLING SER PY 1998 BP 321 EP 331 PG 11 WC Materials Science, Multidisciplinary; Mathematics, Applied; Metallurgy & Metallurgical Engineering SC Materials Science; Mathematics; Metallurgy & Metallurgical Engineering GA BN41C UT WOS:000081854900019 ER PT B AU Hanson, KM Cunningham, GS Saquib, SS AF Hanson, KM Cunningham, GS Saquib, SS BE Erickson, GJ Rychert, JT Smith, CR TI Inversion based on computational simulations SO MAXIMUM ENTROPY AND BAYESIAN METHODS SE Fundamental Theories of Physics LA English DT Proceedings Paper CT 17th International Workshop on Maximum Entropy and Bayesian Methods of Statistical Analysis CY AUG 04-08, 1997 CL BOISE STATE UNIV, BOISE, ID HO BOISE STATE UNIV DE simulation; inversion; reconstruction; adjoint differentiation; sensitivity analysis; optimization; model validation ID TOMOGRAPHIC RECONSTRUCTION; IMAGE-RECONSTRUCTION; MODELS AB A standard approach to solving inversion problems that involve many parameters uses gradient-based optimization to find the parameters that best match the data. We will discuss enabling techniques that facilitate application of this approach to large-scale computational simulations, which are the only way to investigate many complex physical phenomena. Such simulations may not seem to lend themselves to calculation of the gradient with respect to numerous parameters. However, adjoint differentiation allows one to efficiently compute the gradient of an objective function with respect to all the variables of a simulation. When combined with advanced gradient-based optimization algorithms, adjoint differentiation permits one to solve very large problems of optimization or parameter estimation. These techniques will be illustrated through the simulation of the time-dependent diffusion of infrared light through tissue, which has been used to perform optical tomography. The techniques discussed have a wide range of applicability to modeling including the optimization of models to achieve a desired design goal. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, MS P940, Los Alamos, NM 87545 USA. EM kmh@lanl.gov; cunning@lanl.gov; saquib@polaroid.com RI Cunningham, Gregory/F-1017-2011 OI Cunningham, Gregory/0000-0001-8819-4345 NR 34 TC 8 Z9 8 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-5047-2 J9 FUND THEOR PHYS PY 1998 VL 98 BP 121 EP 135 PG 15 WC Mathematics, Applied; Physics, Mathematical; Statistics & Probability SC Mathematics; Physics GA BM77X UT WOS:000079747300010 ER PT S AU Touboltsev, VS Johnson, E Dahmen, U Johansen, A Sarholt, L Xiao, SQ AF Touboltsev, VS Johnson, E Dahmen, U Johansen, A Sarholt, L Xiao, SQ BE Baro, MD Surinach, S TI Formation of Pb inclusions in Si by ion implantation SO MECHANICALLY ALLOYED, METASTABLE AND NANOCRYSTALLINE MATERIALS, PART 1 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Symposium on Metastable, Mechanically Alloyed and Nanocrystalline Materials (ISMANAM 97) CY AUG 31-SEP 05, 1997 CL BARCELONA, SPAIN SP Air Liquide, Caixa Catalunya, Carburos Metal, Carl Zeiss SA, CIRIT, Minist Educ & Cultura, Direcc Gen Ensenanza Super, Fritsch GMBH, Fdn Catalana Recerca, Inst Estudis Calanas, Oxford Instruments, Pacisa, Perkin Elmer, Philips Instrumentac Electr SA, Retsch GMBH, Trallero & Schlee SL, Univ Autonoma Barcelona, ZOZ GMBH DE lead nanocrystals; ion implantation; ion beam channelling; transmission electron microscopy; melting/solidification AB Si < 110 > single crystals were implanted in a random direction at a temperature of 835 K with 150 keV Pb+ ions to a fluence of 1.10(20) m(-2) corresponding to a mean implantation depth of about 60 nm and an average concentration of 2-3 at%. The implanted samples have been studied by Rutherford Backscattering (RBS)/channelling and transmission electron microscopy (TEM) techniques. The RES analysis showed that in as-implanted samples the main fraction of implanted Pb was located on substitutional sites in the Si matrix thus providing a highly supersaturated solution of Pb in Si. Spontaneous precipitation of Pb, giving rise to formation of nanosized Pb inclusions, was found to take place only in the peak region of the implantation profile where the Pb concentration was highest (similar to 4 at.%). TEM analysis of the as-implanted Si crystals showed that the Pb precipitates had sizes from about 2 to 20 nm and that they grew in parallel cube orientation relationship with the host matrix. The shape of the inclusions was found to be approximately cuboctahedral with poorly developed {111} and {100} facets. In-situ RES/channelling heating/cooling experiments on both as-implanted samples and samples previously furnace-annealed at 1175 K showed a distinct melting/solidification hysteresis of the Pb inclusions around the bulk melting point for Pb at 600 K. These results were verified by insitu TEM heating/cooling experiments on as-implanted samples. C1 Niels Bohr Inst, Orsted Lab, DK-2100 Copenhagen 0, Denmark. UC Berkeley, EO Lawrence Berkeley Natl Lab, Natl Ctr Electron Microscopy, Berkeley, CA USA. RP Sarholt, L (reprint author), Niels Bohr Inst, Orsted Lab, Univ Pk 5, DK-2100 Copenhagen 0, Denmark. NR 0 TC 7 Z9 7 U1 0 U2 0 PU TRANSTEC PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-800-1 J9 MATER SCI FORUM PY 1998 VL 269-2 BP 345 EP 350 PN 1 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BK79U UT WOS:000073437400053 ER PT S AU Schwarz, RB AF Schwarz, RB BE Baro, MD Surinach, S TI Microscopic model for mechanical alloying SO MECHANICALLY ALLOYED, METASTABLE AND NANOCRYSTALLINE MATERIALS, PART 2 SE Materials Science Forum LA English DT Article; Proceedings Paper CT International Symposium on Metastable, Mechanically Alloyed and Nanocrystalline Materials (ISMANAM 97) CY AUG 31-SEP 05, 1997 CL BARCELONA, SPAIN SP Air Liquide, Caixa Catalunya, Carburos Metal, Carl Zeiss SA, CIRIT, Minist Educ & Cultura, Direcc Gen Ensenanza Super, Fritsch GMBH, Fdn Catalana Recerca, Inst Estudis Calanas, Oxford Instruments, Pacisa, Perkin Elmer, Philips Instrumentac Electr SA, Retsch GMBH, Trallero & Schlee SL, Univ Autonoma Barcelona, ZOZ GMBH ID SOLID-STATE REACTION; INTERNAL-FRICTION PEAK; ROOM-TEMPERATURE; POWDERS; PROGRAMS; DYNAMICS; SYSTEMS; METALS; MOSI2; CU AB We present a microscopic model for the mechanical alloying (MA) of a mixture of two or more elemental ductile powders. The MA produces fresh metal/metal surfaces and a high density of dislocations. The model is based on dislocation kinetics and the diffusion of solutes along the dislocation cores. For short time intervals T(1), on the order of microseconds, powder particles are subjected to high stresses which exceed their mechanical strength. However, for times T(2) on the order of seconds, the powder particles are unaffected by the milling process. During T(2), solutes diffuse along the cores of these dislocations. During successive T(1) periods, the dislocations are mechanically forced to glide, leaving behind strings of solutes in states of supersaturation. The model is used to explain the formation of extended solid solutions and amorphous alloys, as well as many other unusual effects observed during MA. C1 Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RP Schwarz, RB (reprint author), Los Alamos Natl Lab, Ctr Mat Sci, Mail Stop K765, Los Alamos, NM 87545 USA. NR 59 TC 81 Z9 83 U1 0 U2 2 PU TRANS TECH PUBLICATIONS LTD PI STAFA-ZURICH PA LAUBLSRUTISTR 24, CH-8717 STAFA-ZURICH, SWITZERLAND SN 0255-5476 BN 0-87849-801-X J9 MATER SCI FORUM PY 1998 VL 269-2 BP 665 EP 674 PN 2 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA BK79V UT WOS:000073437500024 ER PT S AU Voter, AF Germann, TC AF Voter, AF Germann, TC BE Wille, LT Burmester, CP Terakura, K Comsa, G Williams, ED TI Accelerating the dynamics of infrequent events: Combining hyperdynamics and parallel replica dynamics to treat epitaxial layer growth SO MECHANISMS AND PRINCIPLES OF EPITAXIAL GROWTH IN METALLIC SYSTEMS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Mechanisms and Principles of Epitaxial Growth in Metallic Systems at the Materials-Research-Society Spring Meeting CY APR 13-14, 1998 CL SAN FRANCISCO, CA SP Mat Res Soc, Natl Inst Stand & Technol, Ctr Theoret & Comp Mat Sci, Hitachi Ltd, IBM, RS 6000 Div, NEC Corp, Sun Microsyst AB During the growth of a surface, morphology-controlling diffusion events occur over time scales that far exceed those accessible to molecular dynamics (MD) simulation. Kinetic Monte Carlo offers a way to reach much longer times, but suffers from the fact that the dynamics are correct only if all possible diffusion events are specified in advance. This is difficult due to the concerted nature of many of the recently discovered surface diffusion mechanisms and the complex configurations that arise during real growth. Here we describe two new approaches for this type of problem. The first, hyperdynamics, is an accelerated MD method, in which the trajectory is run on a modified potential energy surface and time is accumulated as a statistical property. Relative to regular MD, hyperdynamics can give computational gains of more than 10(2). The second method offers a way to parallelize the dynamics efficiently for systems too small for conventional parallel MD algorithms. Both methods exploit the infrequent-event nature of the diffusion process. After an introductory description of these methods, we present preliminary results from simulations combining the two approaches to reach near-millisecond time scales on systems relevant to epitaxial metal growth. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Voter, AF (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. OI Voter, Arthur/0000-0001-9788-7194 NR 0 TC 15 Z9 15 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-434-3 J9 MATER RES SOC SYMP P PY 1998 VL 528 BP 221 EP 236 PG 16 WC Chemistry, Physical; Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA BL49D UT WOS:000075688700023 ER PT S AU Bartelt, MC Evans, JW Schmid, AK Hwang, RQ AF Bartelt, MC Evans, JW Schmid, AK Hwang, RQ BE Wille, LT Burmester, CP Terakura, K Comsa, G Williams, ED TI Island size and environment dependence of adatom capture: Cu/Co islands on Ru(0001) SO MECHANISMS AND PRINCIPLES OF EPITAXIAL GROWTH IN METALLIC SYSTEMS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Mechanisms and Principles of Epitaxial Growth in Metallic Systems at the Materials-Research-Society Spring Meeting CY APR 13-14, 1998 CL SAN FRANCISCO, CA SP Mat Res Soc, Natl Inst Stand & Technol, Ctr Theoret & Comp Mat Sci, Hitachi Ltd, IBM, RS 6000 Div, NEC Corp, Sun Microsyst AB The rate of capture by stable Co islands on Ru(0001) of additionally deposited Gu atoms is quantified using scanning tunneling microscopy, kinetic Monte Carlo simulations, and diffusion equation analyses. We find strong dependence of the capture rates on Go-island size, larger islands showing larger capture rates, qualitatively distinct from self-consistent mean-field predictions. The observed size dependence is shown to reflect larger island-free areas surrounding bigger islands, i.e., a strong correlation between island sizes and separations neglected in mean-field treatments. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Bartelt, MC (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-434-3 J9 MATER RES SOC SYMP P PY 1998 VL 528 BP 253 EP 260 PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA BL49D UT WOS:000075688700025 ER PT S AU Hanson, KM Cunningham, GS AF Hanson, KM Cunningham, GS BE Hanson, KM TI Posterior sampling with improved efficiency SO MEDICAL IMAGING 1998: IMAGE PROCESSING, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Medical Imaging 1998 Conference on Image Processing CY FEB 23-26, 1998 CL SAN DIEGO, CA SP SPIE, Amer Assoc Physicists Med, Amer Physiol Soc, FDA Ctr Devices & Radiat Hlth, Soc Imaging Sci & Technol, Natl Elect Manufacturers Assoc, Diagnost Imaging & Therapy Syst Div, Radiol Informat Syst Consortium, Radiol Soc N Amer, Soc Comp Applicat Radiol DE adaptive Markov Chain Monte Carlo; statistical efficiency; BFGS optimization; Bayesian analysis; uncertainty estimation AB The Markov Chain Monte Carlo (MCMC) technique provides a means to generate a random sequence of model realizations that sample the posterior probability distribution of a Bayesian analysis. That sequence may be used to make inferences about the model uncertainties that derive from measurement uncertainties. This paper presents an approach to improving the efficiency of the Metropolis approach to MCMC by incorporating an approximation to the covariance matrix of the posterior distribution. The covariance matrix is approximated using the update formula from the BFGS quasi-Newton optimization algorithm. Examples are given for uncorrelated and correlated multidimensional Gaussian posterior distributions. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hanson, KM (reprint author), Univ Calif Los Alamos Natl Lab, MS P940, Los Alamos, NM 87545 USA. RI Cunningham, Gregory/F-1017-2011 OI Cunningham, Gregory/0000-0001-8819-4345 NR 0 TC 20 Z9 20 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2783-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3338 BP 371 EP 382 DI 10.1117/12.310914 PN 1 & 2 PG 12 WC Engineering, Biomedical; Optics; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Optics; Radiology, Nuclear Medicine & Medical Imaging GA BL38V UT WOS:000075346500037 ER PT J AU Yoo, MH Fu, CL AF Yoo, MH Fu, CL TI Physical constants, deformation twinning, and microcracking of titanium aluminides SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Fundamentals of Gamma Titanium Aluminides at the TMS Annual Meeting CY FEB 10-12, 1997 CL ORLANDO, FLORIDA SP ASMI MSCTS Flow & Fracture Comm, ASMI MSCTS Phase Transformat Comm ID PLANAR FAULT ENERGIES; AT-PERCENT AL; ELASTIC-CONSTANTS; TI-AL; TEMPERATURE-DEPENDENCE; SINGLE-CRYSTALS; ELECTRONIC-STRUCTURE; SELF-DIFFUSION; YIELD STRESS; STOICHIOMETRIC COMPOSITION AB Physical properties that are relevant to mechanical behavior of single-phase TiAl and Ti3Al and two-phase TiAI/Ti3Al alloys are summarized. By using planar-fault energies and temperature-dependent elastic constants, dislocation dissociation reactions applicable to twin formation in TiAl are analyzed, and a pole mechanism based on a jogged [110]/2 ordinary dislocation is proposed to explain the available experimental data on deformation twinning in gamma-TiAl single crystals. The strong plastic anisotropy reported in TiAl polysynthetically twinned (PST) crystals is attributed in part to the localized slip along lamellar interfaces, thus lowering the yield stress for soft orientations. The experimental findings reported on cleavage habit planes of PST crystals are discussed in terms of the calculated ideal work of adhesion and possible extrinsic factors. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Yoo, MH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. NR 121 TC 87 Z9 91 U1 2 U2 18 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JAN PY 1998 VL 29 IS 1 BP 49 EP 63 DI 10.1007/s11661-998-0158-2 PG 15 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YU733 UT WOS:000071748800006 ER PT J AU Maziasz, PJ Liu, CT AF Maziasz, PJ Liu, CT TI Development of ultrafine lamellar structures in two-phase gamma-TiAl alloys SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Fundamentals of Gamma Titanium Aluminides at the TMS Annual Meeting CY FEB 10-12, 1997 CL ORLANDO, FLORIDA SP ASMI MSCTS Flow & Fracture Comm, ASMI MSCTS Phase Transformat Comm ID TITANIUM ALUMINIDES; BEHAVIOR AB Processing of two-phase gamma-TiAl alloys (Ti-47Al-2Cr-2Nb, or minor modifications thereof) above the alpha-transus temperature (T-alpha) produced unique refined-colony/ultrafine lamellar structures in both powder-and ingot-metallurgy (PM and IM, respectively) alloys. These ultrafine lamellar structures consist of fine laths of the gamma and alpha(2) phases, with average interlamellar spacings (lambda(L)) of 100 to 200 nm and alpha(2)-alpha(2) spacings (lambda(alpha)) of 200 to 500 nm, and are dominated by gamma/alpha(2) interfaces. This characteristic microstructure forms by extruding PM Ti-47Al-2Cr-2Nb alloys at 1400 degrees C and also forms with finer colony size but slightly coarser, fully lamellar structures by hot-extruding similar IM alloys. Alloying additions of B and W refine lambda(L) and lambda(alpha) in both IM Ti-47Al (cast and heat treated at 1400 degrees C) and IM Ti-47Al-2Cr-2Nb alloys (extruded at 1400 degrees C). The ultrafine lamellar structure in the PM alloy remains stable during heat treatment at 900 degrees C for 2 hours but becomes unstable after 4 hours at 982 degrees C; the ultrafine lamellar structure remains relatively stable after aging for >5000 hours at 800 degrees C. Additions of B + W dramatically improve the coarsening resistance of lambda(L) and lambda(alpha) in the IM Ti-47Al alloys aged for 168 hours at 1000 degrees C. In both the PM and IM Ti-47Al-2Cr-2Nb alloys, these refined-colony/ultrafine lamellar structures correlate with high strength and good ductility at room temperature, and very good strength at high temperatures. While refining the colony size improves the room-temperature ductility, alloys with finer lambda(L) are stronger at both room and high temperatures. Additions of B + W produce finer as-processed lambda(L) and lambda(alpha) in IM TiAl alloys and stabilize such structures during heat treatment or aging. C1 Oak Ridge Natl Lab, Div Met & Ceram, Alloying Behav & Design Grp, Oak Ridge, TN 37831 USA. RP Maziasz, PJ (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Alloying Behav & Design Grp, POB 2008, Oak Ridge, TN 37831 USA. OI Maziasz, Philip/0000-0001-8207-334X NR 36 TC 102 Z9 112 U1 2 U2 15 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JAN PY 1998 VL 29 IS 1 BP 105 EP 117 DI 10.1007/s11661-998-0163-5 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YU733 UT WOS:000071748800011 ER PT J AU Docobo, JA Spalding, RE Ceplechla, Z Diaz-Fierros, F Tamazian, V Onda, Y AF Docobo, JA Spalding, RE Ceplechla, Z Diaz-Fierros, F Tamazian, V Onda, Y TI Investigation of a bright flying object over northwest Spain, 1994 January 18 SO METEORITICS & PLANETARY SCIENCE LA English DT Article AB On the early morning of 1994 January 18, a very bright luminous object crossed the sky of Santiago de Compostela, Spain. From visual sightings, it is concluded that the object wasn't a meteoric fireball (bolide). A surface "crater" in Cando (close to Santiago) with dimensions 29 x 13 m and 1.5 m deep was later discovered within 1 km of the projected "impact" point of the luminous object. At this site, in addition to the topsoil, full-grown pine trees >20 m high were thrown downhill over a nearby road, leaving the downslope edge of the "crater" untouched and with a steep interior wall (this would not be the case if a regular landslide were responsible for the transport). Standing trees below the "crater" showed embedded soil and plant residues up to heights >3 m. No strange materials (meteorites or artifacts) were recovered in or close to the "crater"; all materials belonged to the site and were not shocked; thus, an impact is very improbable. A possible explanation capable of reconciling all of the observations is presented. It hypothesizes an eruption of earth gases to create the crater, with the rising gas plume then interacting with atmospheric electricity to produce the propagating fireball that was observed. C1 Acad Sci Czech Republ, Astron Inst, Ondrejov Observ 25165, Czech Republic. Univ Santiago de Compostela, Astron Observ Ramon Maria Aller, Santiago De Compostela, Spain. Sandia Natl Labs, Albuquerque, NM 87185 USA. Nagoya Univ, Nagoya, Aichi 46401, Japan. Univ Santiago de Compostela, Dept Soil Sci, Santiago De Compostela, Spain. RP Ceplechla, Z (reprint author), Acad Sci Czech Republ, Astron Inst, Ondrejov Observ 25165, Czech Republic. RI Onda, Yuichi/N-6527-2014 OI Onda, Yuichi/0000-0001-8753-0378 NR 5 TC 15 Z9 15 U1 3 U2 5 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JAN PY 1998 VL 33 IS 1 BP 57 EP 64 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA YT237 UT WOS:000071579600007 ER PT J AU Biino, GG Groning, P Meisel, T AF Biino, GG Groning, P Meisel, T TI Weathering and polymerization of tektites: An x-ray photoelectron spectroscopy (XPS) investigation SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID AUSTRALASIAN TEKTITES; GLASSES; CONSTRAINTS; DISSOLUTION; ORIGIN AB Tektites are natural glasses formed from terrestrial material that was melted and displaced by the impact of an extraterrestrial body. The surface and near-surface compositions of tektite glass results from fractionation during impact and ejection, and/or postsolidification weathering. The first goal of this study was to characterise the surface and near-surface (in the order of tens of angstroms) chemical composition of two tektites by x-ray photoelectron spectroscopy (XPS), and to estimate the importance of weathering vs. fractionation during flying. In order to separate the chemical modification due to weathering from that due to fractionation during ballistic flight, we studied two samples from the Australasian tektite strewn field. One of them was collected in a hot desert area (Nullarbor Plain, Australia) and the other, in a humid climate (Thailand). Our study reveals the presence of well-developed leached layers in both tektites. In the Australian tektite, Si is depleted in the topmost layers (a few tens of angstroms). A more complex chemical zoning is defined in the tektite from Thailand. These leached layers are comparable to those observed in weathered glasses, and therefore we conclude that weathering is responsible for the chemical composition of the surface and near-surface compositions. The second goal was to investigate the chemical environment of O, N and C in the glass. The O peak was resolved into two bridging O components (Si-O-Si and Al-O-Si) that are comparable to O environments in artificial glasses. The binding energy of the C-ls electron is typical for C-C and C-H bonds in hydrocarbons minor organic acid components are also present. Nitrogen is only observed on the surface of the Thailand tektite. The binding energy of N-ls is comparable to that of ammonia, and the surface enrichment in N is interpreted as due to sorption related to interactions between glass and fluid buffered by the organic material in the soil. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Fribourg, Inst Mineral & Petrog, CH-1700 Fribourg, Switzerland. Univ Fribourg, Dept Phys, CH-1700 Fribourg, Switzerland. Unv Leoben, A-8700 Leoben, Austria. RP Univ Fribourg, Inst Mineral & Petrog, CH-1700 Fribourg, Switzerland. EM giuseppe@electron.lbl.gov RI Meisel, Thomas/B-3637-2009 OI Meisel, Thomas/0000-0001-5572-3212 NR 55 TC 2 Z9 2 U1 0 U2 0 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1086-9379 EI 1945-5100 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JAN PY 1998 VL 33 IS 1 BP 89 EP 95 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA YT237 UT WOS:000071579600010 ER PT S AU Swanson, BI Shi, JX Johnson, S Yang, XG AF Swanson, BI Shi, JX Johnson, S Yang, XG BE Fearey, BL TI Sensors for buried land mines based on guest-host recognition and self-assembly SO METHODS FOR ULTRASENSITIVE DETECTION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Methods for Ultrasensitive Detection CY JAN 26-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE land mines; microsensors; SAW devices; self-assembled monolayer; films; cyclodextrins; host-guest interaction AB Species selective and sensitive films were designed and fabricated for sensing explosives such as TNT. The molecular recognition host reagents were functionalized and covalently attached to a surface acoustic wave (SAW) transducer surface for detecting nitroaromatic species in gas phase. The selectivity and sensitivity of the film are based on host-guest interaction between the host reagent (cyclodextrins) and gas phase species. The film fabrication employs molecular self-assembly technique to construct stable and organized films. The self-assembled monolayer film containing permethylated beta-cyclodextrin can detect o-nitrotoluene at 60 parts per billion. The multilayer films based on covalently attached cyclodextrin polymers can detect o-nitrotoluene at 600 parts per trillion. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Swanson, BI (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, MS J565, Los Alamos, NM 87545 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2709-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3270 BP 25 EP 31 DI 10.1117/12.308383 PG 7 WC Optics SC Optics GA BL19U UT WOS:000074659200003 ER PT S AU Zhao, X Guckert, R Crane, S Vieira, DJ AF Zhao, X Guckert, R Crane, S Vieira, DJ BE Fearey, BL TI Developing optical traps for ultra-sensitive analysis SO METHODS FOR ULTRASENSITIVE DETECTION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Methods for Ultrasensitive Detection CY JAN 26-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE magneto-optical trap; radioactive atoms; ultra-sensitive detection AB We describe the coupling of a magneto-optical trap to a mass separator for the ultra-sensitive detection of selected radioactive species. As a proof of principle test, we have demonstrated the trapping of -6 million Rb-82 (t(1/2) = 75 s) atoms using an ion implantation and heated foil release method of introducing the sample into a trapping cell with minimal gas loading. Gamma-ray counting techniques were used to determine the efficiencies of each step in the process. By far the weakest step in the process is the efficiency of the optical trap itself (0.3%). Further improvements in the quality of the nonstick dryfilm coating on the inside of the trapping cell and the possible use of larger diameter laser beams are indicated. In the presence of a large background of scattered light, this initial work achieved a detection sensitivity of similar to 4,000 trapped atoms. Improved detection schemes using a pulsed trap and gated photon detection method are outlined. Application of this technology to the areas of environmental monitoring and nuclear proliferation are foreseen. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Zhao, X (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2709-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3270 BP 70 EP 76 DI 10.1117/12.308364 PG 7 WC Optics SC Optics GA BL19U UT WOS:000074659200008 ER PT S AU Hughes, RJ AF Hughes, RJ BE Fearey, BL TI Quantum computing with trapped ions SO METHODS FOR ULTRASENSITIVE DETECTION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Methods for Ultrasensitive Detection CY JAN 26-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers AB The significance of quantum computation for cryptography is discussed. Following a brief survey of the requirements for quantum computational hardware, an overview of the ion trap quantum computation project at Los Alamos is presented. The physical limitations to quantum computation with trapped ions are analyzed and an assessment of the computational potential of the technology is made. C1 Univ Calif Los Alamos Natl Lab, Phys Div, Los Alamos, NM 87545 USA. RP Hughes, RJ (reprint author), Univ Calif Los Alamos Natl Lab, Phys Div, POB 1663,H803, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2709-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3270 BP 120 EP 130 DI 10.1117/12.308370 PG 11 WC Optics SC Optics GA BL19U UT WOS:000074659200014 ER PT S AU Pellin, MJ Nicolussi, GK AF Pellin, MJ Nicolussi, GK BE Fearey, BL TI Trace, isotopic analysis of micron-sized grains - Mo, Zr analysis of stardust (SiC and graphite grains) SO METHODS FOR ULTRASENSITIVE DETECTION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Methods for Ultrasensitive Detection CY JAN 26-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE photoionization; surface analysis; resonance ionization mass spectrometry; stardust; isotopic analysis; meteorites; nucleosynthesis AB Secondary Neutral Mass Spectrometry using resonant laser ionization can provide for both high useful yields and high discrimination while maintaining high lateral and depth resolutions. An example of the power of the method is measurement of the isotopic composition of Mo and Zr in 1-5 mu m presolar SiC and graphite grains isolated from the Murchison CM2 meteorite for the first time. These grains have survived the formation of the Solar System, and isotopic analysis reveals a record of the stellar nucleosynthesis present during their formation. Mo and Zr, though present at less than 10 ppm in some grains, are particularly useful in that among their isotopes are members that can only be formed by distinct nucleosynthetic processes known as s-, p-, and r-process. Successful isotopic analysis of these elements requires both high selectivity (since these are trace elements) and high efficiency (since the total number of atoms available are limited). Resonant Ionization Spectroscopy is particularly useful and flexible in this application. While the sensitivity of this technique has often been reported in the past, we focus here on the very low noise properties of the technique. We further demonstrate the efficacy of noise removal by two complimentary methods. First we use the resonant nature of the signal to subtract background signal. Second we demonstrate that by choosing the appropriate resonance scheme background can often be dramatically reduced. C1 Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP Pellin, MJ (reprint author), Argonne Natl Lab, Div Sci Mat, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Pellin, Michael/B-5897-2008 OI Pellin, Michael/0000-0002-8149-9768 NR 0 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2709-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3270 BP 148 EP 157 DI 10.1117/12.308373 PG 10 WC Optics SC Optics GA BL19U UT WOS:000074659200017 ER PT S AU Barnes, MD Lermer, N Kung, CY Whitten, WB Ramsey, JM AF Barnes, MD Lermer, N Kung, CY Whitten, WB Ramsey, JM BE Fearey, BL TI Probing single molecules in microcavities SO METHODS FOR ULTRASENSITIVE DETECTION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Methods for Ultrasensitive Detection CY JAN 26-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers AB We describe recent results of experiments probing single molecules on the surface of spherical microcavities. Effects of spatial photoselection have been recently observed through changes in the single-molecule fluorescence photon statistics. In addition to being a sensitive probe of the highly interesting boundary region between classical and quantum mechanics, cavity-modified spontaneous emission and the possibility of single-molecule stimulated emission hold exciting promise as a means of exceeding sensitivity limitations such as photobleaching and absorption saturation in single molecule fluorescence detection. Ongoing efforts such as fluorescence imaging of single molecules on the surface of microspheres and attempts to observe single-molecule stimulated emission will also be described. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Barnes, MD (reprint author), Oak Ridge Natl Lab, MS 6142, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2709-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3270 BP 182 EP 189 DI 10.1117/12.308377 PG 8 WC Optics SC Optics GA BL19U UT WOS:000074659200021 ER PT S AU Ambrose, WP Goodwin, PM Enderlein, J Semin, DJ Keller, RA AF Ambrose, WP Goodwin, PM Enderlein, J Semin, DJ Keller, RA BE Fearey, BL TI Probing the heterogeneous fluorescence lifetime behavior of single rhodamine-6G molecules on fused silica SO METHODS FOR ULTRASENSITIVE DETECTION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Methods for Ultrasensitive Detection CY JAN 26-28, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE single molecule detection; fluorescence lifetime; near-field microscopy; far-field microscopy; fluorescence photon antibunching AB Heterogeneity in the environments of molecules affects their photophysical parameters. Changes in the local environments or changes within the molecules themselves produces fluctuations in the photophysical parameters. We have explored the fluorescence lifetime and intensity fluctuations of Rhodamine 6G on silica using time correlated single photon counting combined with near-field and far-field scanning optical microscopies, and fluorescence photon-pair correlation measurements in far-field microscopy. In the most recent work, we find complex behavior in the fluorescence lifetime and emission intensity in the millisecond to minute time range that must be associated with changes in both the non-radiative and the radiative decay rates. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Ambrose, WP (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Mail Stop M888, Los Alamos, NM 87545 USA. NR 0 TC 2 Z9 2 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2709-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3270 BP 190 EP 199 DI 10.1117/12.308379 PG 10 WC Optics SC Optics GA BL19U UT WOS:000074659200022 ER PT J AU Wall, JS Hainfeld, JF Simon, MN AF Wall, JS Hainfeld, JF Simon, MN TI Scanning transmission electron microscopy of nuclear structures SO METHODS IN CELL BIOLOGY, VOL 53 SE METHODS IN CELL BIOLOGY LA English DT Review ID PYRUVATE-DEHYDROGENASE COMPLEX; FILAMENTS ASSEMBLED INVITRO; HIGHER-ORDER STRUCTURE; INTERMEDIATE FILAMENTS; MASS ANALYSIS; UNDECAGOLD CLUSTER; MOLECULAR-WEIGHT; MACROMOLECULAR COMPLEXES; RIBOSOMAL-SUBUNIT; EPIDERMAL KERATIN C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Wall, JS (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. FU NCRR NIH HHS [P41-RR01777] NR 67 TC 38 Z9 38 U1 0 U2 3 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0091-679X J9 METHOD CELL BIOL PY 1998 VL 53 BP 139 EP 164 PG 26 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA BK68A UT WOS:000073060900008 PM 9348508 ER PT J AU Berland, K Jacobson, K French, T AF Berland, K Jacobson, K French, T TI Electronic cameras for low-light microscopy SO METHODS IN CELL BIOLOGY, VOLUME 56 SE METHODS IN CELL BIOLOGY LA English DT Review ID IMAGING MICROSCOPY; MOLECULES; CELL C1 Univ N Carolina, Lineberger Comprehens Canc Ctr, Chapel Hill, NC 27599 USA. Univ N Carolina, Dept Cell Biol & Anat, Chapel Hill, NC 27599 USA. Sandia Natl Labs, Nanostruct & Semicond Phys Dept, Albuquerque, NM 87185 USA. RP Berland, K (reprint author), Univ N Carolina, Lineberger Comprehens Canc Ctr, Chapel Hill, NC 27599 USA. FU NIGMS NIH HHS [GM35325, GM41402]; NINDS NIH HHS [NS10351] NR 18 TC 4 Z9 5 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0091-679X J9 METHOD CELL BIOL PY 1998 VL 56 BP 19 EP 44 DI 10.1016/S0091-679X(08)60419-7 PG 26 WC Cell Biology SC Cell Biology GA BK58S UT WOS:000072625700002 PM 9500131 ER PT S AU Gleason, SS Tobin, KW Kamowski, TP Lakhani, F AF Gleason, SS Tobin, KW Kamowski, TP Lakhani, F BE Singh, B TI Rapid yield learning through optical defect and electrical test analysis SO METROLOGY, INSPECTION, AND PROCESS CONTROL FOR MICROLITHOGRAPHY XII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Metrology, Inspection, and Process Control for Microlithography XII CY FEB 23-25, 1998 CL SANTA CLARA, CA SP Soc Photo Opt Instrumentat Engineers, Semiconductor Equipment & Mat Int, SEMATECH DE electrical test; spatial pattern recognition; semiconductor inspection; moments AB As semiconductor device density and wafer area continue to increase, the volume of in-line and off-line data required to diagnose yield-limiting conditions is growing exponentially. To manage this data in the future, analysis tools will be required that can automatically reduce this data to useful information, e.g., by assisting the engineer in rapid root-cause diagnosis of defect generating mechanisms. In this paper, we describe a technology known as Spatial Signature Analysis (SSA) and its application to both optically-detected defect data as well as electrical test (e-test) bin data. The results of a validation study are summarized that demonstrate the effectiveness of the SSA approach on optical defect wafermaps through field-testing at three semiconductor manufacturing sites on ASIC, DRAM and SRAM products. This method has been extended to analyze and interpret electrical test data and to provide a pathway for correlation of this data with in-line optical measurements. The image processing-based, fuzzy classifier system used for optical defect SSA has been adopted and applied to e-test binmaps to interpret and rapidly identify characteristic patterns, or "signatures", in the binmap data that are uniquely associated with the manufacturing process. An image of the binmap is created, and features such as mass, simple moments, and invariant moments are extracted and presented to a pair-wise, fuzzy, k-NN classifier. The preliminary performance results show an 84% correct e-test signature classification rate, even under sub-optimal training conditions. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Gleason, SS (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 10 Z9 10 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2777-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3332 BP 232 EP 242 DI 10.1117/12.308731 PG 11 WC Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL31M UT WOS:000075068300024 ER PT S AU Gourley, PL French, T McDonald, AE Shields, EA AF Gourley, PL French, T McDonald, AE Shields, EA BE Gourley, PL Katzir, A TI Ultrasensitive detection of red blood cell lysing in a microfabricated semiconductor laser cavity SO MICRO- AND NANOFABRICATED STRUCTURES AND DEVICES FOR BIOMEDICAL ENVIRONMENTAL APPLICATIONS SE PROGRESS IN BIOMEDICAL OPTICS LA English DT Proceedings Paper CT Conference on Microfabricated and Nanofabricated Structures and Devices for Biomedical Environmental Applications CY JAN 26-27, 1998 CL SAN JOSE, CA SP SPIE, Int Soc Opt Engn, Int Biomed Opt Soc AB In this paper we report investigations of semiconductor laser microcavities for use in detecting changes of human blood cells during lysing. By studying the spectra before and during mixing of blood fluids with de-ionized water,we are able to quantify the cell shape and concentration of hemoglobin in real time during the dynamical process of lysing. We find that the spectra can detect subtle changes that are orders of magnitude smaller than can be observed by standard optical microscopy. Such sensitivity in observing cell structural changes has implications for measuring cell fragility, monitoring apoptotic events in real time, development of photosensitizers for photodynamic therapy, and in-vitro cell micromanipulation techniques. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Gourley, PL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 1017-2661 BN 0-8194-2697-0 J9 PROG BIOM O PY 1998 VL 3258 BP 195 EP 206 DI 10.1117/12.304380 PG 12 WC Engineering, Multidisciplinary; Engineering, Biomedical; Optics SC Engineering; Optics GA BK80K UT WOS:000073452100024 ER PT S AU Mariella, R AF Mariella, R BE Gourley, PL Katzir, A TI Microtechnology for instrumentation SO MICRO- AND NANOFABRICATED STRUCTURES AND DEVICES FOR BIOMEDICAL ENVIRONMENTAL APPLICATIONS SE PROGRESS IN BIOMEDICAL OPTICS LA English DT Proceedings Paper CT Conference on Microfabricated and Nanofabricated Structures and Devices for Biomedical Environmental Applications CY JAN 26-27, 1998 CL SAN JOSE, CA SP SPIE, Int Soc Opt Engn, Int Biomed Opt Soc DE microtechnology; instrumentation; PCR; flow cytometry; gas chromatography; DNA sequencing; microchannel; Human Genome Project AB For the last two decades, the majority of research and development at LLNL in microtechnology has focused on photonics devices and bulk micromachining, including micro-electro-mechanical systems (MEMS) and associated areas. For the last ten years, we have used these capabilities to address our analytical instrumentation needs. Just as the integrated circuits in the 1960's enabled the fabrication of portable electronics, MEMS and miniature photonics have enabled the fabrication of analytical instruments that are either higher performance, smaller, more portable, or are combinations of these. Examples of these are our portable thermal cyclers for DNA analysis, our hand-held gas chromatograph, our flow-stream-waveguide-based flow cytometer, and our etched-microchannel electrophoresis systems. This presentation will describe these and some related developments. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Microtechnol, Livermore, CA 94551 USA. RP Mariella, R (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Microtechnol, POB 808,Mail Stop L-222, Livermore, CA 94551 USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 1017-2661 BN 0-8194-2697-0 J9 PROG BIOM O PY 1998 VL 3258 BP 216 EP 223 PG 8 WC Engineering, Multidisciplinary; Engineering, Biomedical; Optics SC Engineering; Optics GA BK80K UT WOS:000073452100026 ER PT B AU Garcia, EJ AF Garcia, EJ GP IEEE TI Micro-flex mirror and instability actuation technique SO MICRO ELECTRO MECHANICAL SYSTEMS - IEEE ELEVENTH ANNUAL INTERNATIONAL WORKSHOP PROCEEDINGS LA English DT Proceedings Paper CT 11th Annual International Workshop on Micro Electro Mechanical Systems CY JAN 25-29, 1998 CL HEIDELBERG, GERMANY SP IEEE, Robot & Automat Soc, ASME, Div Dynam Syst & Control, Minist Econ Affairs Baden Wurttemberg AB This paper reports on the design and fabrication of a surface micromachined mirror system which is capable of producing the required moments to rotate a mirror structure out of the plane of fabrication. The planar structures created by surface micromachining present difficulties with developing a sufficient moment to move structures out of the x-y plane when actuated by those same planar structures. This is due to the short moment arms (in thickness direction z) that can be created in the fabrication process. The instability actuation technique reported here has general application to moving 2-dimensional structures up and out of the plane of their original fabrication. This technique can be applied to "build" truly 3-dimensional structures from a nearly 2-dimensional fabrication process. Surface micromachining can now be considered a 3-dimensional process where 3-dimensional structures are built by raising up structures by the instability actuation technique and making appropriate mechanical interconnections. C1 Sandia Natl Labs, Electromech Engn Dept, Albuquerque, NM 87185 USA. RP Garcia, EJ (reprint author), Sandia Natl Labs, Electromech Engn Dept, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 18 Z9 18 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4412-X PY 1998 BP 470 EP 475 DI 10.1109/MEMSYS.1998.659803 PG 2 WC Automation & Control Systems; Engineering, Biomedical; Engineering, Electrical & Electronic; Engineering, Mechanical SC Automation & Control Systems; Engineering GA BK78X UT WOS:000073380900085 ER PT S AU Krulevitch, P Johnson, GC AF Krulevitch, P Johnson, GC BE Brown, S Gilbert, J Guckel, H Howe, R Johnson, G Krulevitch, P Muhlstein, C TI Curvature of a cantilever beam subjected to an equi-biaxial bending moment SO MICROELECTROMECHANICAL STRUCTURES FOR MATERIALS RESEARCH SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Microelectromechanical Structures for Materials Research CY APR 15-16, 1998 CL SAN FRANCISCO, CA SP Mat Res Soc AB Results from a finite element analysis of a cantilever beam subjected to an equi-biaxial bending moment demonstrate that the biaxial modulus E/(1-nu) must be used even for narrow beams. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Microtechnol, Livermore, CA 94551 USA. RP Krulevitch, P (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Microtechnol, POB 808, Livermore, CA 94551 USA. NR 7 TC 9 Z9 9 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-424-6 J9 MATER RES SOC SYMP P PY 1998 VL 518 BP 67 EP 72 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Engineering; Materials Science; Metallurgy & Metallurgical Engineering GA BM24W UT WOS:000078172100011 ER PT S AU de Boer, MP Clews, PJ Smith, BK Michalske, TA AF de Boer, MP Clews, PJ Smith, BK Michalske, TA BE Brown, S Gilbert, J Guckel, H Howe, R Johnson, G Krulevitch, P Muhlstein, C TI Adhesion of polysilicon microbeams in controlled humidity ambients SO MICROELECTROMECHANICAL STRUCTURES FOR MATERIALS RESEARCH SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Microelectromechanical Structures for Materials Research CY APR 15-16, 1998 CL SAN FRANCISCO, CA SP Mat Res Soc ID GLASS AB We characterize in-situ the adhesion of surface micromachined polysilicon beams subject to controlled humidity ambients. Beams were freed by supercritical CO2 drying. Consistent adhesion results were obtained using a post-treatment in an oxygen plasma which rendered the microbeams uniformly hydrophilic. Individual beam deformations were measured by optical interferometry after equilibration at a given relative humidity (RH). Validation of each adhesion measurement was accomplished by comparing the deformations with elasticity theory. The data indicates that adhesion increases exponentially with RH from 30% to 95%, with values from 1 mJ/m(2) to 50 mJ/m(2). Using the Kelvin equation, we show that the data should be independent of RH if a smooth interface is considered. By modeling a rough interface consistent with atomic force microscopy (AFM) data, the exponential trend is satisfactorily explained. C1 Sandia Natl Labs, Dept Intelligent Micromachining 1325, Albuquerque, NM 87185 USA. RP de Boer, MP (reprint author), Sandia Natl Labs, Dept Intelligent Micromachining 1325, POB 5800, Albuquerque, NM 87185 USA. NR 25 TC 43 Z9 43 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-424-6 J9 MATER RES SOC SYMP P PY 1998 VL 518 BP 131 EP 136 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Engineering; Materials Science; Metallurgy & Metallurgical Engineering GA BM24W UT WOS:000078172100021 ER PT S AU Christenson, TR Buchheit, TE Schmale, DT Bourcier, RJ AF Christenson, TR Buchheit, TE Schmale, DT Bourcier, RJ BE Brown, S Gilbert, J Guckel, H Howe, R Johnson, G Krulevitch, P Muhlstein, C TI Mechanical and metallographic characterization of LIGA fabricated nickel and 80%Ni-20%Fe permalloy SO MICROELECTROMECHANICAL STRUCTURES FOR MATERIALS RESEARCH SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Microelectromechanical Structures for Materials Research CY APR 15-16, 1998 CL SAN FRANCISCO, CA SP Mat Res Soc AB A table top servohydraulic load frame equipped with a laser displacement measurement system was constructed for the mechanical characterization of LIGA fabricated electroforms. A drop-in tensile specimen geometry which includes a pattern to identify gauge length via laser scanning has proven to provide a convenient means to monitor and characterize mechanical property variations arising during processing. In addition to tensile properties, hardness and metallurgical data were obtained for nickel deposit specimens of current density varying between 20 and 80 mA/cm(2) from a sulfamate based bath. Data from 80/20 nickel/iron deposits is also presented for comparison. As expected, substantial mechanical property differences from bulk metal properties are observed as well as a dependence of material strength on current density which is supported by grain size variation. While elastic modulus values of the nickel electrodeposit are near 160 GPa, yield stress values vary by over 60%. A strong orientation in the metal electrodeposits as well as variations in nucleating and growth morphology present a concern for anisotropic and geometry dependent mechanical properties within and between different LIGA components. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Christenson, TR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI bourcier, romain/D-6896-2015 OI bourcier, romain/0000-0002-6506-4019 NR 14 TC 27 Z9 27 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-424-6 J9 MATER RES SOC SYMP P PY 1998 VL 518 BP 185 EP 190 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Engineering; Materials Science; Metallurgy & Metallurgical Engineering GA BM24W UT WOS:000078172100030 ER PT S AU Matzke, CM Arnold, DW Ashby, CIH Kravitz, SH Warren, ME Bailey, CG AF Matzke, CM Arnold, DW Ashby, CIH Kravitz, SH Warren, ME Bailey, CG BE Frazier, AB Ahn, CH TI Quartz channel fabrication for electrokinetically driven separations SO MICROFLUIDIC DEVICES AND SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Microfluidic Devices and Systems CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE microchannel; integrated channel; micromachined channel; packed channel; electrokinetic channel; electrophoretic channel AB For well resolved electrokinetic separation, we utilize crystalline quartz to micromachine a uniformly packed separation channel. Packing features are posts 5 mu m on a side with 3 mu m spacing and etched 42 mu m deep. In addition to anisotropic wet etch characteristics for micromachining, quartz properties are compatible with chemical solutions, electrokinetic high voltage operation, and stationary phase film depositions. To seal these channels, we employ a room temperature silicon-oxynitride deposition to form a membrane, that is subsequently coated for mechanical stability. Using this technique, particulate issues and global warp, that make large area wafer bonding methods difficult, are avoided, and a room temperature process, in contrast to high temperature bonding techniques, accommodate preprocessing of metal films for electrical interconnect. After sealing channels, a number of macro-assembly steps are required to attach a micro-optical detection system and fluid interconnects. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Matzke, CM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 8 Z9 8 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2974-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3515 BP 164 EP 171 DI 10.1117/12.322078 PG 8 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Fluids & Plasmas SC Engineering; Instruments & Instrumentation; Physics GA BL77P UT WOS:000076705100017 ER PT S AU Martin, PM Matson, DW Bennett, WD Hammerstrom, DJ AF Martin, PM Matson, DW Bennett, WD Hammerstrom, DJ BE Frazier, AB Ahn, CH TI Fabrication of plastic microfluidic components SO MICROFLUIDIC DEVICES AND SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Microfluidic Devices and Systems CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE microfluidics; sensor; micromachining; lamination AB Plastic components have many advantages, including ease of fabrication, low cost, chemical inertness, lightweight, and disposability. We report on the fabrication of three plastics-based microfliudic components: a motherboard, a dialysis unit, and a metal sensor. Microchannels, headers, and interconnects were produced in thin sheets (greater than or equal to 50 microns) of polyimide, PMMA, polyethylene, and polycarbonate using a direct-write excimer laser micromachining system. Machined sheets were laminated by thermal and adhesive bonding to form leak-tight microfluidic components. The microfluidic motherboard borrowed the "functionality on a chip" concept from the electronics industry and was the heart of a complex microfluidic analytical device. The motherboard platform was designed to be tightly integrated and self-contained (i.e., liquid flows are all confined within machined microchannels), reducing the need for tubing for fluid distribution and connectivity. This concept greatly facilitated system integration and miniaturization. As fabricated, the motherboard consisted of three fluid reservoirs connected to micropumps by microchannels. The fluids could either be pumped independently or mixed in microchannels prior to being directed to exterior analytical components via outlet ports. The microdialysis device was intended to separate electrolytic solutes from low volume samples prior to mass spectrometric analysis. The device consisted of a dialysis membrane laminated between opposed serpentine microchannels containing the sample fluid and a buffer solution. The laminated metal sensor consisted of fluid reservoirs, micro-flow channels, micropumps, mixing channels, reaction channels, and detector circuitry. C1 Battelle Mem Inst, Pacific NW Labs, Richland, WA 99352 USA. RP Martin, PM (reprint author), Battelle Mem Inst, Pacific NW Labs, POB 999, Richland, WA 99352 USA. NR 0 TC 29 Z9 29 U1 1 U2 10 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2974-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3515 BP 172 EP 176 DI 10.1117/12.322079 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Fluids & Plasmas SC Engineering; Instruments & Instrumentation; Physics GA BL77P UT WOS:000076705100018 ER PT S AU Smith, JH Rodgers, MS Sniegowski, JJ Miller, SL Hetherington, D McWhorter, PJ Warren, ME AF Smith, JH Rodgers, MS Sniegowski, JJ Miller, SL Hetherington, D McWhorter, PJ Warren, ME BE French, PJ Chau, K TI Microelectro-optical devices in a 5-level polysilicon surface micromachining technology SO MICROMACHINED DEVICES AND COMPONENTS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Micromachined Devices amd Components IV CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE MEMS; MOEMS; polysilicon; mirror; shutter; re-direction; microactuator AB We recently reported on the development of a 5-level polysilicon surface micromachine fabrication process' consisting of four levels of mechanical poly plus an electrical interconnect layer and its application(2) to complex mechanical systems. This paper describes the application of this technology to create micro-optical systems-on-a-chip. These are demonstration systems, which show that five levels of polysilicon provide greater performance, reliability, and significantly increased functionality. This new technology makes it possible to realize levels of system complexity that have so far only existed on paper, while simultaneously adding to the robustness of many of the individual subassemblies. C1 Sandia Natl Labs, Intelligent Micromachine Dept, Albuquerque, NM 87185 USA. RP Smith, JH (reprint author), Sandia Natl Labs, Intelligent Micromachine Dept, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 4 Z9 4 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2973-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3514 BP 42 EP 47 DI 10.1117/12.323889 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BL81E UT WOS:000076796500005 ER PT S AU Casalnuovo, SA Heller, EJ Hietala, VM Baca, AG Kottenstette, R Hietala, SL Reno, JL Frye-Mason, GC AF Casalnuovo, SA Heller, EJ Hietala, VM Baca, AG Kottenstette, R Hietala, SL Reno, JL Frye-Mason, GC BE French, PJ Chau, K TI Acoustic wave chemical microsensors in GaAs SO MICROMACHINED DEVICES AND COMPONENTS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Micromachined Devices amd Components IV CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE gallium arsenide; aluminum gallium arsenide; microsensor; surface acoustic wave; flexural plate wave; micromachining; integration AB High sensitivity acoustic wave chemical microsensors are being developed on GaAs substrates. These devices take advantage of the piezoelectric properties of GaAs as well as its mature microelectronics fabrication technology and nascent micromachining technology. The design, fabrication, and response of GaAs SAW chemical microsensors are reported. Functional integrated GaAs SAW oscillators, suitable for chemical sensing, have been produced. The integrated oscillator requites 20 mA at 3 V-DC operates at frequencies up to 500 MHz, and occupies approximately 2 mm(2). Discrete GaAs sensor components, including IC amplifiers, SAW delay lines, and IC phase comparators have been fabricated and tested. A temperature compensation scheme has been developed that overcomes the large temperature dependence of GaAs acoustic wave devices. Packaging issues related to bonding miniature flow channels directly to the GaAs substrates have been resolved. Micromachining techniques for fabricating FPW and TSM microsensors on thin GaAs membranes are presented and GaAs FPW delay line performance is described. These devices have potentially higher sensitivity than existing GaAs and quartz SAW sensors. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Casalnuovo, SA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2973-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3514 BP 103 EP 110 DI 10.1117/12.323923 PG 8 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BL81E UT WOS:000076796500011 ER PT S AU Eaton, WP Smith, NF Irwin, L Tanner, DM AF Eaton, WP Smith, NF Irwin, L Tanner, DM BE French, PJ Chau, K TI Characterization techniques for surface-micromachined devices SO MICROMACHINED DEVICES AND COMPONENTS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Micromachined Devices amd Components IV CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE AB Using a microengine as the primary test vehicle, we have examined several aspects of characterization. Parametric measurements provide fabrication process information. Drive signal optimization is necessary for increased microengine performance. Finally, electrical characterization of resonant frequency and quality factor can be more accurate than visual techniques. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Eaton, WP (reprint author), Sandia Natl Labs, Mail Stop 1081, Albuquerque, NM 87185 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2973-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3514 BP 171 EP 178 DI 10.1117/12.323884 PG 8 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BL81E UT WOS:000076796500017 ER PT S AU Matson, DW Martin, PM Tonkovich, ALY Roberts, GL AF Matson, DW Martin, PM Tonkovich, ALY Roberts, GL BE French, PJ Chau, K TI Fabrication of a stainless steel microchannel microcombustor using a lamination process SO MICROMACHINED DEVICES AND COMPONENTS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Micromachined Devices amd Components IV CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE combustion; lamination; microchannel; chemical reactor; fuel processor AB Microscale chemical devices have potential application as fuel processors to produce high purity hydrogen for PEM fuel cells from hydrocarbon fuels such as methane, methanol, ethanol, or gasoline. The fabrication of a novel stainless steel catalytic microcombustor/reactor suitable for use to high temperatures is described. The device consisted of three parts to accommodate catalyst loading: a laminated reactor body, a laminated combustor, and a solid cover plate. The laminated components were produced using stacks of photochemically machined stainless steel shims. When formed into solid leak-tight components using a diffusion bonding process, the laminated parts were designed to contain a complex series of internal gas-now microchannels that could not be produced in a solid metal block by other fabrication methods: Included within the reactor body was an array of heat exchanger microchannels 250 microns wide and 5000 microns deep that were designed to extract heat from the catalytic reaction region and pre-heat the reactant gases. Catalytic combustion of hydrogen or hydrocarbon fuel occurred in a separate laminated combustor plate. The laminated combustor/reactor design has potential for use in a variety of chemical processing and heat exchanger applications. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Matson, DW (reprint author), Pacific NW Natl Lab, POB 999,MSIN K3-59, Richland, WA 99352 USA. NR 0 TC 13 Z9 13 U1 0 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2973-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3514 BP 386 EP 392 DI 10.1117/12.323912 PG 7 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BL81E UT WOS:000076796500040 ER PT S AU Eaton, WP Smith, NF Irwin, L Tanner, DM AF Eaton, WP Smith, NF Irwin, L Tanner, DM BE French, PJ Chau, K TI Characterization techniques for surface-micromachined devices SO MICROMACHINED DEVICES AND COMPONENTS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Micromachined Devices amd Components IV CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE AB Using a microengine as the primary test vehicle, we have examined several aspects of characterization. Parametric measurements provide fabrication process information. Drive signal optimization is necessary for increased microengine performance. Finally, electrical characterization of resonant frequency and quality factor can be more accurate than visual techniques. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Eaton, WP (reprint author), Sandia Natl Labs, Mail Stop 1081, Albuquerque, NM 87185 USA. NR 0 TC 9 Z9 9 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2973-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3514 BP 431 EP 438 DI 10.1117/12.323919 PG 8 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BL81E UT WOS:000076796500046 ER PT S AU Smith, BK Brown, CD LaVigne, G Sniegowski, JJ AF Smith, BK Brown, CD LaVigne, G Sniegowski, JJ BE Smith, JH TI Thin Teflon-like films for MEMS: Film properties and reliability studies SO MICROMACHINING AND MICROFABRICATION PROCESS TECHNOLOGY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Micromachining and Microfabrication Process Technology IV CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE micromachining; adhesion; stiction; Teflon; microstructures; fluorocarbon; polysilicon; MEMS AB This work presents film properties and initial reliability studies for thin Teflon-like films applied to a unique test vechicle, the Sandia-designed and fabricated microengine. Results on microengines coated with the film show a factor of three improvement in their lifetime and an order of magnitude reduction in the coefficient of friction when compared to uncoated samples. Coefficients Of Friction (COF) of 0.07 for the Teflon-like film and 1.0 for uncoated samples are extracted from models which match the measured behavior of working microengines. These films, deposited ii om a plasma source, exhibit the ability to penetrate into very narrow, deep channels common to many MEMS devices. For as-deposited film, both the refractive index at 1.4 and the contact angle with water at 108 degrees show the film to be very similar to bulk Teflon PTFE. Film stability as a function of temperature has been examined using Fourier Transform Infrared (FTIR) spectroscopy. The film structure as observed by the fluorine-carbon (F-C) peak is stable up to 200 C, but starts decomposing above 250 C. Film composition has been examined using X-ray photoelectron spectroscopy (XPS) and is quite different for directly exposed surfaces compared with deep, narrow channels where the deposition process is diffusion limited. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Smith, BK (reprint author), Sandia Natl Labs, POB 5800,MS 1084, Albuquerque, NM 87185 USA. NR 0 TC 6 Z9 6 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2970-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3511 BP 114 EP 124 DI 10.1117/12.324289 PG 11 WC Engineering, Industrial; Engineering, Manufacturing SC Engineering GA BL85N UT WOS:000076937000013 ER PT S AU Fleming, JG AF Fleming, JG BE Smith, JH TI Combining the best of bulk and surface micromachining using Si {111} substrates SO MICROMACHINING AND MICROFABRICATION PROCESS TECHNOLOGY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Micromachining and Microfabrication Process Technology IV CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE {111} Si; bulk micromachining; trench etch; KOH; surface micromachining AB This process combines the best features of bulk and surface micromachining. It enables the production of stress free, thick, virtually arbitrarily shaped structures with well defined thick or thin sacrificial layers, high sacrificial layer selectivity and large undercuts using IC compatible, processes. The basis of this approach is the use of readily available {111} oriented substrates, anisotropic Si trench etching, SiN masking and KOH etching. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Fleming, JG (reprint author), Sandia Natl Labs, POB 5800,MS 1084,Org 1723, Albuquerque, NM 87185 USA. NR 0 TC 8 Z9 8 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2970-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3511 BP 162 EP 168 DI 10.1117/12.324294 PG 7 WC Engineering, Industrial; Engineering, Manufacturing SC Engineering GA BL85N UT WOS:000076937000018 ER PT S AU Christenson, TR AF Christenson, TR BE Smith, JH TI Advances in LIGA-based post-mold fabrication SO MICROMACHINING AND MICROFABRICATION PROCESS TECHNOLOGY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Micromachining and Microfabrication Process Technology IV CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE LIGA; MEMS; magnetic materials; permanent magnets; assembly; packaging; diffusion bonding AB The establishment of a process to allow planarization of deep x-ray lithography based microfabricated metal components via diamond lapping has enabled examination of three additional microfabrication issues. The areas of improvement that are discussed include materials, microassembly and packaging, and multilevel fabrication. New materials work has centered on magnetic materials including precision micromagnets and surface treatments of electrodeposited materials. Assembly and packaging has been aided by deep silicon etch processing and the use of conventional precision milling equipment combined with press-fit assembly. Diffusion bonding is shown to be a particularly important approach to achieving multilevel metal mechanisms and furthermore shows promise for achieving batch assembled and packaged high aspect-ratio metal micromechanics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Christenson, TR (reprint author), Sandia Natl Labs, POB 5800,MS-0329, Albuquerque, NM 87185 USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2970-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3511 BP 192 EP 203 DI 10.1117/12.324299 PG 12 WC Engineering, Industrial; Engineering, Manufacturing SC Engineering GA BL85N UT WOS:000076937000022 ER PT S AU Shul, RJ Willison, CG Zhang, L AF Shul, RJ Willison, CG Zhang, L BE Smith, JH TI Selective, deep Si trench etching with dimensional control SO MICROMACHINING AND MICROFABRICATION PROCESS TECHNOLOGY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Micromachining and Microfabrication Process Technology IV CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE high-aspect ratio silicon etching; inductively coupled plasma etching; aspect ratio dependent etching; dimensional control AB The recent development of a high-aspect ratio Si etch (HARSE) process(1) has enabled the fabrication of a variety of Si structures where deep trench etching is necessary. The HARSE process relies on the formation of a sidewall etch inhibitor to prevent lateral etching of the Si structures during exposure to an aggressive SF6/Ar plasma etch chemistry. The process yields highly anisotropic profiles with excellent dimensional control for high aspect ratio features. In this study, Si etch rates and etch selectivities to photoresist are reported as a function of chamber pressure, cathode rf-power, ICP source power, and gas flow. Si etch rates > 3 mu m/min with etch selectivities to resist > 75:1 were obtained. Lateral dimensional control, etch selectivities to SiO2 and Si3N4, and aspect ratio dependent etching (ARDE) will also be discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Shul, RJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 6 Z9 6 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2970-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3511 BP 252 EP 261 DI 10.1117/12.324308 PG 10 WC Engineering, Industrial; Engineering, Manufacturing SC Engineering GA BL85N UT WOS:000076937000028 ER PT S AU Matzke, CM Kottenstette, RJ Casalnuovo, SA Frye-Mason, GC Hudson, ML Sasaki, DY Manginell, RP Wong, CC AF Matzke, CM Kottenstette, RJ Casalnuovo, SA Frye-Mason, GC Hudson, ML Sasaki, DY Manginell, RP Wong, CC BE Smith, JH TI Microfabricated silicon gas chromatographic micro-channels: fabrication and performance SO MICROMACHINING AND MICROFABRICATION PROCESS TECHNOLOGY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Micromachining and Microfabrication Process Technology IV CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE gas chromatography; gas separations; micromachine; high-aspect ratio Si etch (HARSE); deep reactive ion etch (DRIE); open capillary; stationary phase; micro-column; micro-channel AB Using both wet and plasma etching, we have fabricated micro-channels in silicon substrates suitable for use as gas chromatography (GC) columns, Micro-channel dimensions range from 10 to 80 mu m wide, 200 to 400 mu m deep, and 10 cm to 100 cm long. Micro-channels 100 cm long take up as little as 1 cm(2) on the substrate when fabricated with a high aspect ratio silicon etch (HARSE) process. Channels are sealed by anodically bonding Pyrex lids to the Si substrates. We have studied micro-channel flow characteristics to establish model parameters for system optimization. We have also coated these micro-channels with stationary phases and demonstrated GC separations. We believe separation performance can be improved by increasing stationary phase coating uniformity through micro-channel surface treatment prior to stationary phase deposition. To this end, we have developed microfabrication techniques to etch through silicon wafers using the HARSE process. Etching completely through the Si substrate facilitates the treatment and characterization of the micro-channel sidewalls, which dominate the GC physico-chemical interaction. With this approach, we separately treat the Pyrex lid surfaces that form the top and bottom surfaces of the GC flow channel. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Matzke, CM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 34 Z9 35 U1 1 U2 6 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2970-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3511 BP 262 EP 268 DI 10.1117/12.324309 PG 7 WC Engineering, Industrial; Engineering, Manufacturing SC Engineering GA BL85N UT WOS:000076937000029 ER PT S AU Manginell, RP Frye-Mason, GC Schubert, WK Shul, RJ Willison, CG AF Manginell, RP Frye-Mason, GC Schubert, WK Shul, RJ Willison, CG BE Smith, JH TI Microfabrication of membrane-based devices by HARSE and combined HARSE wet etching SO MICROMACHINING AND MICROFABRICATION PROCESS TECHNOLOGY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Micromachining and Microfabrication Process Technology IV CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE HARSE; DRIE; combined HARSE wet etching; microhotplate; FPW; valve; flow sensor; composite membrane AB Deep-reactive ion etching (DRIE) of silicon, also known as high-aspect-ratio silicon etching (HARSE), is distinguished by fast etch rates (similar to 3 mu m/min), crystal orientation independence, anisotropy, vertical sidewall profiles and CMOS compatibility. By using through-wafer HARSE and stopping on a dielectric Nm placed on the opposite side of the wafer, freestanding dielectric membranes were produced. Dielectric membrane-based sensors and actuators fabricated in this way include microhotplates, flow sensors, valves and magnetically-actuated flexural plate wave (FPW) devices. Unfortunately, low-stress silicon nitride, a common membrane material, has an appreciable DRI etch rate. To overcome this problem HARSE can be followed by a brief wet chemical etch. This approach has been demonstrated using KOH or HF/Nitric/Acetic etchants, both of which have significantly smaller etch rates on silicon nitride than does DRIE. Composite membranes consisting of silicon dioxide and silicon nitride layers are also under evaluation due to the higher DRIE selectivity to silicon dioxide. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Manginell, RP (reprint author), Sandia Natl Labs, POB 5800,MS 1425, Albuquerque, NM 87185 USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2970-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3511 BP 269 EP 276 DI 10.1117/12.324310 PG 8 WC Engineering, Industrial; Engineering, Manufacturing SC Engineering GA BL85N UT WOS:000076937000030 ER PT S AU Griffiths, SK Nilson, RH Bradshaw, RW Ting, A Bonivert, WD Hachman, JT Hruby, JM AF Griffiths, SK Nilson, RH Bradshaw, RW Ting, A Bonivert, WD Hachman, JT Hruby, JM BE Smith, JH TI Transport limitations in electrodeposition for LIGA microdevice fabrication SO MICROMACHINING AND MICROFABRICATION PROCESS TECHNOLOGY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Micromachining and Microfabrication Process Technology IV CY SEP 21-22, 1998 CL SANTA CLARA, CA SP SPIE DE LIGA; electrodeposition; electroforming; transport AB To better understand and to help optimize the electroforming portion of the LIGA process, we have developed one and two-dimensional numerical models describing electrodeposition of metal into high aspect-ratio molds. The one-dimensional model addresses dissociation, diffusion, electromigration, and deposition of multiple ion species. The two-dimensional model is limited to a single species, but includes transport induced by forced how of electrolyte outside the mold and by buoyancy associated with metal ion depletion within the mold. To guide model development and to validate these models, we have also conducted a series of laboratory experiments using a sulfamate bath to deposit nickel in cylindrical molds having aspect ratios up to twenty-five. The experimental results indicate that current densities well in excess of diffusion-limited currents may still yield acceptable morphologies in the deposited metal. However, the numerical models demonstrate that such large ion fluxes cannot be sustained by convection within the mold resulting from flow across the mold top. Instead, calculations suggest that the observed hundredfold enhancement of transport probably results from natural convection within the molds and that buoyancy-driven flows may be critical to metal ion transport even in micron-scale features having very large aspect ratios. Taking advantage of this enhanced ion transport may allow order-of-magnitude reductions in electroforming times for LIGA microdevice fabrication. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Griffiths, SK (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. NR 0 TC 16 Z9 17 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2970-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3511 BP 364 EP 375 DI 10.1117/12.324324 PG 12 WC Engineering, Industrial; Engineering, Manufacturing SC Engineering GA BL85N UT WOS:000076937000042 ER PT S AU Matson, DW Martin, PM Bennett, WD AF Matson, DW Martin, PM Bennett, WD BE Sulzmann, A Nelson, BJ TI Laser machined components for microanalytical and chemical separation devices SO MICROROBOTICS AND MICROMANIPULATION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Microrobotics and Micromanipulation CY NOV 04-05, 1998 CL BOSTON, MA SP SPIE DE dialysis; laser; membrane; microanalytical; microchannel; micromachining AB Excimer lasers have proven to be powerful tools for machining polymeric components used in microanalytical and microchemical separation devices. We report the use of laser machining methods to produce microfluidic channels and liquid/liquid contact membranes for a number of devices fabricated at our laboratory. Microchannels 50- to 100-mu m-wide have been produced directly in bulk polycarbonate chips using a direct-write laser micromachining system. Wider microchannels have been produced by laser machining paths through sheets of polyimide film, then sandwiching the patterned piece between solid chips of polycarbonate stock. A comparison of direct-write and mask machining processes used to produce some of the microfluidic features is made. Examples of microanalytical devices produced using these methods are presented. Included are microdialysis units used to remove electrolytes from liquid samples and electrophoretic separation devices, both used for extremely low volume samples intended for mass spectrometric analysis. A multilayered microfluidic device designed to analyze low volume groundwater samples for hazardous metals and a fluidics motherboard are also described. Laser machining processes have also been explored for producing polymeric membranes suitable for use in liquid/liquid contactors used for removal of soluble hazardous components from waste streams. A step-and-repeat mask machining process was used to produce 0.5 x 8 cm membranes in 25- and 50-mu m-thick polyimide. Pore diameters produced using this method were five and ten micrometers. The laser machined membranes were sputter coated with PTFE prior to use to improve fluid breakthrough characteristics. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Matson, DW (reprint author), Pacific NW Natl Lab, POB 999,MSIN K3-59, Richland, WA 99352 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2980-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3519 BP 200 EP 207 DI 10.1117/12.325741 PG 8 WC Automation & Control Systems; Engineering, Industrial SC Automation & Control Systems; Engineering GA BL85Y UT WOS:000076962700021 ER PT S AU Feddema, JT Keller, CG Howe, RT AF Feddema, JT Keller, CG Howe, RT BE Sulzmann, A TI Experiments in micromanipulation and CAD-driven microassembly SO MICROROBOTICS AND MICROSYSTEM FABRICATION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Microrobotics and Microsystem Fabrication CY OCT 16-17, 1997 CL PITTSBURGH, PA SP Soc Photo Opt Instrumentat Engineers, NIST, Coalit Intelligent Mfg Syst, Acad Coalit Intelligent Mfg Syst DE microassembly; micromanipulation; microtweezers; visual servoing; LIGA; MEMS AB This paper discusses recent experiments in the manipulation and assembly of parts with 100 micron outside dimensions and submicron tolerances. The objective of this work is to develop a micromanipulation workcell which can automatically assemble LIGA (Lithography Galvonoforming Abforming) parts using an assembly plan and a CAD drawing of each of the components. The workcell consists of an AdeptOne robot, precision stages, and long distance microscope, and a high aspect ratio molded polysilicon tweezers for picking up the parts. Fourier optics methods are used to generate synthetic microscope images from CAD drawings. These synthetic images are used off-line to test image processing routines under varying magnifications and depths of field. They also provide reference image features which are used to visually servo the true part to the desired position. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Feddema, JT (reprint author), Sandia Natl Labs, POB 5800,MS 1003, Albuquerque, NM 87185 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2634-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3202 BP 98 EP 107 DI 10.1117/12.298027 PG 10 WC Automation & Control Systems; Engineering, Mechanical; Optics SC Automation & Control Systems; Engineering; Optics GA BK45Z UT WOS:000072274000010 ER PT J AU Benson, DA Mitchell, RT Tuck, MR Palmer, DW Peterson, GP AF Benson, DA Mitchell, RT Tuck, MR Palmer, DW Peterson, GP TI Ultrahigh-capacity micromachined heat spreaders SO MICROSCALE THERMOPHYSICAL ENGINEERING LA English DT Article ID PIPE AB Micro heat pipes and microscale flat-plate heat pipes processed as an integral part of semiconductor devices are examined as an alternative to polycrystalline diamond or aluminum nitride (AIN) ceramic heat spreaders. We review several means that have been proposed for fabricating microscale heat pipe designs within electronic die or as substrate heat spreaders. We then report testing techniques and new experimental results for a silicon spreader design we developed. The results show that incorporating these phase-change heat spreaders as an integral part of semiconductor devices significantly decreases the temperature gradient across a chip and decreases the maximum chip temperature. Significant process and production issues remain, but the test results clearly show that this approach is a feasible alternative cooling technique that merits serious consideration for microelectronic heat transfer applications. C1 Texas A&M Univ, Royce E Wisenbaker Engn Res Ctr 301, Dept Engn Mech, College Stn, TX 77843 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Peterson, GP (reprint author), Texas A&M Univ, Royce E Wisenbaker Engn Res Ctr 301, Dept Engn Mech, College Stn, TX 77843 USA. NR 16 TC 23 Z9 23 U1 0 U2 4 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1089-3954 J9 MICROSCALE THERM ENG JI Microscale Thermophys. Eng. PD JAN-MAR PY 1998 VL 2 IS 1 BP 21 EP 30 PG 10 WC Thermodynamics; Engineering, Mechanical; Nanoscience & Nanotechnology; Materials Science, Characterization & Testing; Physics, Applied SC Thermodynamics; Engineering; Science & Technology - Other Topics; Materials Science; Physics GA ZJ903 UT WOS:000073265300004 ER PT S AU Morris, JR Lu, ZY Ring, DM Xiang, JB Ho, KM Wang, CZ Fu, CL AF Morris, JR Lu, ZY Ring, DM Xiang, JB Ho, KM Wang, CZ Fu, CL BE Phillpot, SR Bristowe, PD Stroud, DG Smith, JR TI Structure, energy, and electronic properties of the Sigma=13{510} tilt grain boundary structure in Si SO MICROSCOPIC SIMULATION OF INTERFACIAL PHENOMENA IN SOLIDS AND LIQUIDS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Microscopic Simulation of Interfacial Phenomena in Solids and Liquids, at the 1997 MRS Fall Meeting CY DEC 01-04, 1997 CL BOSTON, MA SP Mat Res Soc, Argonne Natl Lab, Gen Motors AB We have examined a variety of structures for the {510} symmetric tilt boundary in Si, using first-principles calculations. These calculations show that the observed structure in Si is the lowest energy structure. This structure is more complicated than what is necessary to preserve four-fold coordination. We compare the results to classical and tight-binding models, in order to test these empirical approaches. C1 Iowa State Univ Sci & Technol, Ames Lab, Dept Phys & Astron, US Dept Energy, Ames, IA 50011 USA. RP Morris, JR (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Dept Phys & Astron, US Dept Energy, Ames, IA 50011 USA. RI 上官, 敏慧/E-8964-2012; Morris, J/I-4452-2012 OI Morris, J/0000-0002-8464-9047 NR 0 TC 0 Z9 0 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-397-5 J9 MATER RES SOC SYMP P PY 1998 VL 492 BP 127 EP 132 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Physics, Applied SC Chemistry; Materials Science; Physics GA BK96A UT WOS:000073945200016 ER PT S AU Boettger, JC AF Boettger, JC BE Phillpot, SR Bristowe, PD Stroud, DG Smith, JR TI Thickness dependencies in the calculated properties of metallic ultra-thin films SO MICROSCOPIC SIMULATION OF INTERFACIAL PHENOMENA IN SOLIDS AND LIQUIDS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Microscopic Simulation of Interfacial Phenomena in Solids and Liquids, at the 1997 MRS Fall Meeting CY DEC 01-04, 1997 CL BOSTON, MA SP Mat Res Soc, Argonne Natl Lab, Gen Motors AB Ultra-thin film (UTF) electronic structure calculations are a common tool for investigating surface properties. In this work, electronic structure calculations for Al(111) films ranging from one to twelve atoms thick are used to illustrate some of the difficulties that can arise when one attempts to determine surface properties of metals with UTF calculations. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Boettger, JC (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-397-5 J9 MATER RES SOC SYMP P PY 1998 VL 492 BP 157 EP 167 PG 11 WC Chemistry, Physical; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Physics, Applied SC Chemistry; Materials Science; Physics GA BK96A UT WOS:000073945200021 ER PT S AU Yan, Y Chisholm, MF Duscher, G Pennycook, SJ Maiti, A Pantelides, ST AF Yan, Y Chisholm, MF Duscher, G Pennycook, SJ Maiti, A Pantelides, ST BE Phillpot, SR Bristowe, PD Stroud, DG Smith, JR TI First-principles simulations and Z-contrast imaging of impurities at < 001 > tilt grain boundaries in MgO SO MICROSCOPIC SIMULATION OF INTERFACIAL PHENOMENA IN SOLIDS AND LIQUIDS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Microscopic Simulation of Interfacial Phenomena in Solids and Liquids, at the 1997 MRS Fall Meeting CY DEC 01-04, 1997 CL BOSTON, MA SP Mat Res Soc, Argonne Natl Lab, Gen Motors AB First-principles density-functional calculations were used to study the effects of Ca impurities on the Sigma=5 (310) < 001 > tilt grain boundaries in MgO. An equilibrium structure and two metastable structures of the grain boundaries in pure MgO have been established. The calculations further demonstrated that Ca impurities segregate at particular sites in the metastable grain boundary and induce a structural transformation. This result is consistent with atomic resolution Z-contrast imaging. The calculations also found that the impurities at the grain boundaries do not induce states in the band gap. The mechanism of the transformation is also discussed. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Yan, Y (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Duscher, Gerd/G-1730-2014 OI Duscher, Gerd/0000-0002-2039-548X NR 0 TC 0 Z9 0 U1 0 U2 6 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-397-5 J9 MATER RES SOC SYMP P PY 1998 VL 492 BP 181 EP 186 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Physics, Applied SC Chemistry; Materials Science; Physics GA BK96A UT WOS:000073945200023 ER PT S AU Wilson, WD Schaldach, CM AF Wilson, WD Schaldach, CM BE Phillpot, SR Bristowe, PD Stroud, DG Smith, JR TI H2S and HS- adsorption on a charged Cu surface in an electrolyte: Effect of ionic strength SO MICROSCOPIC SIMULATION OF INTERFACIAL PHENOMENA IN SOLIDS AND LIQUIDS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Microscopic Simulation of Interfacial Phenomena in Solids and Liquids, at the 1997 MRS Fall Meeting CY DEC 01-04, 1997 CL BOSTON, MA SP Mat Res Soc, Argonne Natl Lab, Gen Motors AB We present a method for the calculation of the binding and rotational energies of neutral (H2S) and charged (HS-) molecules impinging upon a charged (Cu [100]) surface in the presence of an electrolyte. A molecular surface is constructed surrounding the H2S and HS- molecules forming boundary elements. A coupled Schrodinger-Poisson-Boltzmann iterative procedure treats the electronic structure of the molecules at the 6-31G**/MP2 level of theory and includes solvation effects through the single and double layers of charge induced by the electronic distribution. The molecule, together with its charged layers, forms a Molecular Single and Double Layer (MSDL), an object which then interacts with a Gouy-Chapman plane within the electrolyte. The additional induced charge at the molecular surface resulting from this electric field is obtained by solving a second set of boundary element equations. Repulsive interactions between the atoms of the molecule and those of the surface are obtained using a rigid-ion Hartree-Fock method. Binding energies of the molecule to the surface are determined as a function of the real surface charge imposed and also the ionic strength of the solution. It is found that surface charges can completely (180 degrees) reorient these molecules and that the counterions in the solution can completely screen binding effects of even large surface charges. Work supported by the United States Department of Energy under contract #DE-AC04-94AL85000. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Wilson, WD (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-397-5 J9 MATER RES SOC SYMP P PY 1998 VL 492 BP 207 EP 212 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Physics, Applied SC Chemistry; Materials Science; Physics GA BK96A UT WOS:000073945200027 ER PT S AU Yoo, MH Fu, CL AF Yoo, MH Fu, CL BE Phillpot, SR Bristowe, PD Stroud, DG Smith, JR TI Interfacial properties and mechanical behavior of titanium aluminides SO MICROSCOPIC SIMULATION OF INTERFACIAL PHENOMENA IN SOLIDS AND LIQUIDS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Microscopic Simulation of Interfacial Phenomena in Solids and Liquids, at the 1997 MRS Fall Meeting CY DEC 01-04, 1997 CL BOSTON, MA SP Mat Res Soc, Argonne Natl Lab, Gen Motors AB The role of various interfaces in deformation and fracture behavior of two-phase TiAl-Ti3Al alloys is analyzed on the basis of the specific interfacial and surface energies determined from ab initio calculations. The propensity of twinning observed in these alloys is consistent with the low true-twin boundary energy. The strong plastic anisotropy reported in TiAl polysynthetically twinned (PST) crystals is attributed partly to the localized slip along lamellar interfaces, thus lowering the yield stress for soft orientations. Interfacial fracture energies are estimated to be the highest for the alpha(2)/gamma lamellar boundary and the lowest for the 120 degrees rotational gamma/gamma boundary. The fracture mode mixity plays an important role in the crack-tip plasticity by ordinary slip and true-twinning, leading to translamellar and interfacial fracture. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Yoo, MH (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-397-5 J9 MATER RES SOC SYMP P PY 1998 VL 492 BP 345 EP 356 PG 12 WC Chemistry, Physical; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Physics, Applied SC Chemistry; Materials Science; Physics GA BK96A UT WOS:000073945200046 ER PT J AU Ren, SX Kenik, EA Alexander, KB Goyal, A AF Ren, SX Kenik, EA Alexander, KB Goyal, A TI Exploring spatial resolution in electron back-scattered diffraction experiments via Monte Carlo simulation SO MICROSCOPY AND MICROANALYSIS LA English DT Article DE Monte Carlo simulation; back-scattered electrons (BSEs); spatial resolution; energy distribution; electron back-scattered diffraction (EBSD) AB A Monte Carlo model was used to simulate specimen-electron beam interactions relevant to electron back-scattered diffraction (EBSD). Electron trajectories were calculated for a variety of likely experimental conditions to examine the interaction volume of the incident electrons as well as that of the subset of incident electrons that emerge from the specimen, i.e., back-scattered electrons (BSEs). The spatial resolution of EBSD was investigated as functions of both materials properties, such as atomic number, atomic weight, and density, and experimental parameters, such as specimen thickness, tilt, and incident beam accelerating voltage. These simulations reveal that the achievable spatial resolution in EBSD is determined by these intrinsic and extrinsic parameters. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Ren, SX (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Bldg 5500,MS 6376,POB 2008, Oak Ridge, TN 37831 USA. NR 14 TC 25 Z9 25 U1 2 U2 21 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1431-9276 J9 MICROSC MICROANAL JI Microsc. microanal. PD JAN-FEB PY 1998 VL 4 IS 1 BP 15 EP 22 PG 8 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA ZY695 UT WOS:000074650100001 ER PT J AU Irdi, GA Warzinski, RP Booher, HB AF Irdi, GA Warzinski, RP Booher, HB TI Application of light microscopy to direct coal liquefaction research SO MICROSCOPY AND MICROANALYSIS LA English DT Article DE liquefaction; vitrinite/vitroplast reflectance; "wall scales"; macerals; conversion AB Light microscopy was used to analyze the effects of added catalyst at different conditions (temperature and reaction times) in liquefaction testing of a low pyritic sulfur bituminous coal. Quantitative changes in vitrinite/vitroplast reflectance of coal and liquefaction residues were shown to be useful markers in analyzing and understanding the role of catalyst during the initial stage of coal particle hydrogenation. Lower reflectance values corresponded to increased conversions up to about the 60 min and 375 degrees C experimental conditions. Microscopical observation of liquefaction residues also revealed the presence of "wall scales" of varying width. C1 US DOE, Fed Energy Technol Ctr, Pittsburgh, PA 15236 USA. RP Irdi, GA (reprint author), US DOE, Fed Energy Technol Ctr, Mail Stop 94-412,POB 10940, Pittsburgh, PA 15236 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1431-9276 J9 MICROSC MICROANAL JI Microsc. microanal. PD JAN-FEB PY 1998 VL 4 IS 1 BP 50 EP 55 PG 6 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA ZY695 UT WOS:000074650100004 ER PT S AU Gopalsami, N Raptis, AC AF Gopalsami, N Raptis, AC BE Afsar, MN TI Remote detection of chemicals by millimeter-wave spectroscopy SO MILLIMETER AND SUBMILLIMETER WAVES IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 4th International Conference on Millimeter and Submillimeter Waves and Applications CY JUL 20-23, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Tufts Univ DE millimeter waves; backward-wave oscillator; molecular spectroscopy; standoff monitoring ID RANGE AB This paper discusses the development and field testing of a remote chemical detection system that is based on millimeter-wave (mm-wave) spectroscopy. The mm-wave system is a monostatic swept-frequency radar that consists of a mm-wave sweeper, a hot-electron-bolometer detector, and a trihedral reflector. The chemical plume to be detected is situated between the transmitter/detector and the reflector. Millimeter-wave absorption spectra of chemicals in the plume are determined by measuring the swept-frequency radar return signals with and without the plume in the beam path. The problem of pressure broadening, which hampered open-path spectroscopy in the past, has been mitigated in this work by designing a fast sweeping source over a broad frequency range. The heart of the system is a Russian backward-wave oscillator (BWO) tube that can be tuned over 225-315 GHz. A mm-wave sweeper that includes the BWO tube was built to sweep the entire frequency range within 10 ms. The radar system was field-tested at the DOE Nevada Test Site at a standoff distance of 60 m. Methyl chloride was released from a wind tunnel that produced a 2-m diameter plume at its exit point. The mm-wave system detected methyl chloride plumes down to a concentration of 12 ppm. The measurement results agree well with model-fitted data. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Gopalsami, N (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2920-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3465 BP 254 EP 265 DI 10.1117/12.331172 PG 2 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BM32U UT WOS:000078393700041 ER PT S AU Dickey, FM Holswade, SC Christenson, TR Garcia, EJ Polosky, MA AF Dickey, FM Holswade, SC Christenson, TR Garcia, EJ Polosky, MA BE Motamedi, ME Goring, R TI Optical measurement of LIGA milliengine performance SO MINIATURIZED SYSTEMS WITH MICRO-OPTICS AND MICROMECHANICS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Miniaturized Systems with Micro-Optics and Micromechanics III CY JAN 26-27, 1998 CL SAN JOSE, CA SP SPIE Int Soc Opt Engn DE micromachines; actuators; optical probe/feedback AB Understanding the parameters that affect the performance of milliscale and microscale actuators is essential to the development of optimized designs and fabrication processes, as well as the qualification of devices for commercial applications. This pa,ner discusses the development of optical techniques for motion measurements of LIGA fabricated milliengines. LIGA processing permits the fabrication of precision millimeter-sized machine elements that cannot be fabricated by conventional miniature machining techniques because of their small feature sizes. In addition, tolerances of 1 part in 10(3) to 10(4) may be maintained in millimeter sized components with this processing technique. Optical techniques offer a convenient means for measuring long term statistical performance data and transient responses needed to optimize designs and manufacturing techniques. Optical techniques can also be used to provide feedback signals needed for control and sensing of the state of the machine. Optical probe concepts and experimental data obtained using a milliengine developed at Sandia National Laboratories are presented. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Dickey, FM (reprint author), Sandia Natl Labs, MS-0328, Albuquerque, NM 87185 USA. NR 0 TC 7 Z9 7 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2715-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3276 BP 28 EP 36 DI 10.1117/12.302397 PG 9 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BK71W UT WOS:000073206500003 ER PT S AU Frigo, JR Tilden, MW AF Frigo, JR Tilden, MW BE Gage, DW TI Analog neural network control method proposed for use in a backup satellite control mode SO MOBILE ROBOTS XII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 12th SPIE Mobile Robots Conference CY OCT 16, 1997 CL PITTSBURGH, PA SP NISTPhoto Opt Instrumentat Engineers, Coalit Intelligent Mfg Syst, Acad Coalit Intelligent Mfg Syst DE analog neural network; autonomous control mode; satellite systems AB We propose to use an analog neural network controller implemented in hardware, independent of the active control system, for use in a satellite backup control mode. The controller uses coarse sun sensor inputs. The field-of-view of the sensors activate the neural controller, creating an analog dead band with respect to the direction of the sun on each axis. This network controls the orientation of the vehicle toward the sunlight to ensure adequate power for the system. The attitude of the spacecraft is stabilized with respect to the ambient magnetic field on orbit. This paper develops a model of the controller using real-time coarse sun sensor data and a dynamic model of a prototype system based on a satellite system. The simulation results and the feasibility of this control method for use in a satellite backup control mode are discussed. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Frigo, JR (reprint author), Univ Calif Los Alamos Natl Lab, MSD466-NIS-1, Los Alamos, NM 87545 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2642-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3210 BP 84 EP 94 DI 10.1117/12.299556 PG 11 WC Automation & Control Systems; Optics SC Automation & Control Systems; Optics GA BK46B UT WOS:000072274900009 ER PT S AU Parker, LE AF Parker, LE BE Choset, HM Gage, DW Kachroo, P Kourjanski, MA deVries, MJ TI Toward the automated synthesis of cooperative mobile robot teams SO MOBILE ROBOTS XIII AND INTELLIGENT TRANSPORTATION SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Mobile Robots XIII and Intelligent Transportation Systems CY NOV 03-05, 1998 CL BOSTON, MA SP Soc Photo Opt Instrumentat Engineers, Soc Mfg Engineers DE cooperative behaviors; behavior synthesis; multi-robot learning AB A current limitation in the real-world use of cooperating mobile robots is the difficulty in determining the proper team composition for a given robotic application. Present technology restricts the design and implementation of cooperative robot teams to the expertise of a robotics researcher, who has to develop robot teams on an application-specific basis. The objective of our research is to reduce the complexity of cooperative robotic systems through the development of a methodology that enables the automated synthesis of cooperative robot teams. We propose an approach to this problem that uses a combination of the theories of sensori-computational systems and information invariants, building on the earlier work of Donald, Rus, et al. We describe the notion of defining equivalence classes that serve as fundamental building blocks of more complex cooperative mobile robot behaviors. We postulate a methodology for framing mission requirements in terms of the goals and constraints of the problem, incorporating issues such as multi-robot interference, communication, control strategy, robot complexity, and so forth, into the mechanism. Our initial work restricts the robot application and design space to three multi-robot application domains we have previously studied and implemented: keeping formation, "mock" hazardous waste cleanup, and cooperative observation. This paper presents the foundational ideas upon which our approach to cooperative team design is based. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Parker, LE (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 11 TC 7 Z9 7 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2986-4 J9 P SOC PHOTO-OPT INS PY 1998 VL 3525 BP 82 EP 93 PG 12 WC Automation & Control Systems; Engineering, Manufacturing; Optics; Transportation SC Automation & Control Systems; Engineering; Optics; Transportation GA BM42S UT WOS:000078690700009 ER PT S AU Frigo, JR Tilden, MW AF Frigo, JR Tilden, MW BE Choset, HM Gage, DW Kachroo, P Kourjanski, MA deVries, MJ TI A biologically inspired neural network controller for an infrared tracking system SO MOBILE ROBOTS XIII AND INTELLIGENT TRANSPORTATION SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Mobile Robots XIII and Intelligent Transportation Systems CY NOV 03-05, 1998 CL BOSTON, MA SP Soc Photo Opt Instrumentat Engineers, Soc Mfg Engineers DE analog neural network; infrared sensors; tracking system AB Many biological systems exhibit capable, adaptive behavior with a minimal nervous system such as those found in lower invertebrates. Scientists and engineers are studying biological systems because these models may have real-world applications. The analog neural controller, herein, is loosely modeled after minimal biological nervous systems. The system consists of the controller and pair of sensors mounted on an actuator. It is implemented with an electrical oscillator network, two infrared sensors and a de motor, used as an actuator for the system. The system tracks an IR target source. The pointing accuracy of this neural network controller is estimated through experimental measurements and a numerical model of the system. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Frigo, JR (reprint author), Univ Calif Los Alamos Natl Lab, MSD448-NIS-4, Los Alamos, NM 87545 USA. NR 14 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2986-4 J9 P SOC PHOTO-OPT INS PY 1998 VL 3525 BP 393 EP 401 PG 9 WC Automation & Control Systems; Engineering, Manufacturing; Optics; Transportation SC Automation & Control Systems; Engineering; Optics; Transportation GA BM42S UT WOS:000078690700038 ER PT B AU Biner, SB AF Biner, SB BE Taleff, EM Mahidhara, RK TI The role of delamination on the ductile fracture behavior of laminated composites SO MODELING THE MECHANICAL RESPONSE OF STRUCTURAL MATERIALS LA English DT Proceedings Paper CT Symposium on Modeling the Mechanical Response of Structural Materials at the 127th Annual Meeting of the Minerals-Metals-and-Materials-Society CY FEB 15-19, 1998 CL SAN ANTONIO, TX SP Minerals Met & Mat Soc, Struct Mat Comm AB In this study, the failure of the ductile layers from collinear and delaminating cracks that occur in laminated composite systems was studied using a constitutive relationship that accounts for strength degradation resulting from the nucleation and growth of voids. The results indicate that in laminated composites, void nucleation and growth ahead of the cracks occur at a much faster rate due to evolution of much higher stress values at the interface region. For delaminating crack cases, the fracture behavior is strongly influenced by the delamination length. The resistance of the ductile layers to crack extension can be significantly reduced by short delamination lengths. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Biner, SB (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-392-9 PY 1998 BP 255 EP 264 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Engineering; Materials Science; Metallurgy & Metallurgical Engineering GA BK53N UT WOS:000072466900026 ER PT B AU Biner, SB AF Biner, SB BE Taleff, EM Mahidhara, RK TI Growth behavior of bridged cracks at creep regime SO MODELING THE MECHANICAL RESPONSE OF STRUCTURAL MATERIALS LA English DT Proceedings Paper CT Symposium on Modeling the Mechanical Response of Structural Materials at the 127th Annual Meeting of the Minerals-Metals-and-Materials-Society CY FEB 15-19, 1998 CL SAN ANTONIO, TX SP Minerals Met & Mat Soc, Struct Mat Comm AB In this study, the growth behavior of bridged cracks in the creep regime is investigated numerically. In the analysis, crack growths resulting from the growth of prenucleated creep cavities with diffusional and dislocation assisted mechanisms are fully accounted for. The bridging elements are assumed to be elastic. The results indicate that the bridging tractions significantly relax even with the creep deformation of the composite alone. A much weaker stress singularity than the ones described by K or C* occurs ahead of the bridged cracks in the creep regime. In this weak singularity region the cavities grow at comparably high rates to each other. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Biner, SB (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-392-9 PY 1998 BP 265 EP 275 PG 11 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Engineering; Materials Science; Metallurgy & Metallurgical Engineering GA BK53N UT WOS:000072466900027 ER PT J AU Mercer, JL Nelson, JS Wright, AF Stechel, EB AF Mercer, JL Nelson, JS Wright, AF Stechel, EB TI Ab initio calculations of the energetics of the neutral Si vacancy defect SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID IMPURITY DIFFUSION; MICROSCOPIC THEORY; SELF-DIFFUSION; POINT-DEFECTS; SILICON; SEMICONDUCTORS; MECHANISMS AB Ab initio plane-wave pseudopotential calculations for the neutral silicon vacancy indicate a formation energy of 3.6 eV, with the surrounding lattice undergoing a tetragonal distortion with the nearby atoms forming two dimers having bond lengths 2.91 Angstrom. Close in energy is a tetrahedrally distorted structure in which the nearby atoms relax towards the vacancy by 12.6% of the bulk bond length. Additional distortions with trigonal symmetry were also investigated, but no stable structures were found. The symmetry, energetics, and geometry are found to be a sensitive function of the computational basis-set and supercell used in the plane-wave calculations. C1 Sandia Natl Labs, Adv Mat & Devices Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Semicond Mat & Device Sci Dept, Albuquerque, NM 87185 USA. RP Mercer, JL (reprint author), Univ Cambridge, Dept Engn, Trumpington St, Cambridge CB2 1PZ, England. RI Stechel, Ellen/B-1253-2012 NR 26 TC 32 Z9 32 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0965-0393 EI 1361-651X J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD JAN PY 1998 VL 6 IS 1 BP 1 EP 8 DI 10.1088/0965-0393/6/1/001 PG 8 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA ZA436 UT WOS:000072363100001 ER PT J AU Baskes, MI Hoagland, RG Tsuji, T AF Baskes, MI Hoagland, RG Tsuji, T TI An atomistic study of the strength of an extended-dislocation barrier SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article AB The stress dependence of a lock consisting of a 1/3 a[100] stair rod symmetrically located between two Shockley partials in face-centred cubic nickel was examined by atomistic simulation. The applied stress forced the partials into the stair rod. As the partials move into the lock with increasing strain, the separation distances are reasonably consistent with a linear elastic calculation of equilibrium separation except at the closest approach where the elastic calculation overestimates the separation. The overestimation is attributable to core overlap. The lock underwent several unstable transitions before becoming an inverted arrangement of its initial configuration. The sequence of transitions involves an asymmetric configuration at 2.3% strain containing an extrinsic fault, a transition at 4.8% strain that changes the stair rod to 1/6 a[011], and a transition that inverts the lock at 6% strain with the stair rod becoming 1/6 a[<(1)over bar 00>]. The evolution of the lock is not reversible. C1 Sandia Natl Labs, Mat Reliabil Dept, Livermore, CA 94551 USA. Washington State Univ, Sch Mech & Mat Engn, Pullman, WA 99164 USA. Shizuoka Univ, Dept Engn Mech, Hamamatsu, Shizuoka 432, Japan. RP Baskes, MI (reprint author), Sandia Natl Labs, Mat Reliabil Dept, Livermore, CA 94551 USA. RI Hoagland, Richard/G-9821-2012 NR 11 TC 23 Z9 23 U1 2 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD JAN PY 1998 VL 6 IS 1 BP 9 EP 18 DI 10.1088/0965-0393/6/1/002 PG 10 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA ZA436 UT WOS:000072363100002 ER PT S AU Wilcox, BP Simanton, JR AF Wilcox, BP Simanton, JR BE Boardman, J FavisMortlock, D TI Predicting runoff in semiarid woodlands: Evaluation of the WEPP model SO MODELLING SOIL EROSION BY WATER SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SERIES I, GLOBAL ENVIRONMENT CHANGE LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Global Change - Modelling Soil Erosion by Water CY SEP 11-14, 1995 CL UNIV OXFORD, OXFORD, ENGLAND SP NATO HO UNIV OXFORD ID PINYON-JUNIPER WOODLANDS; EROSION AB Dramatic environmental changes, either from changing climate or land use, or both, will strongly affect erosion processes in semiarid environments. Forecasting the extent and magnitude of these effects will require models in which we have some degree of confidence - or, at the very least, the limitations of which we fully understand. Validating these models, therefore, is critical. In this study, we evaluate the runoff prediction capabilities of the WEPP model, applied to a semiarid pinyon-juniper woodland of the southwestern United States. The model's parameters were drawn from detailed site characterisation data, including data from rainfall simulation studies (the rainfall line studies involved four 30m(2) plots, two of which were undisturbed; later, the four plots and a nearby 2000 m(2) hillslope were instrumented to gather data on naturally occurring runoff). WEPP was quite successful at simulating naturally occurring runoff from the disturbed plots, but underpredicted runoff from the undisturbed plots by nearly a factor of three. This was a surprising result, given the quantity of detailed information from the plots used as input for the model. One possibility is that the hydraulic conductivity of the soil - which can vary over time depending on surface soil conditions and, perhaps, rainfall characteristics - was different during the studies of naturally occurring runoff than during the rainfall simulation experiments. With respect to runoff from the hillslope, WEPP's estimates were high; actual measured runoff was considerably lower than that from the plots, presumably because of the greater opportunity for storage and subsequent infiltration on the hillslope - a scale effect that the model's design does not take into account. These results point to the need for caution in applying models to scales significantly different from those for which their parameters were developed. C1 Univ Calif Los Alamos Natl Lab, Environm Sci Grp, Los Alamos, NM 87544 USA. RP Wilcox, BP (reprint author), Univ Calif Los Alamos Natl Lab, Environm Sci Grp, POB 1663,MS J495, Los Alamos, NM 87544 USA. NR 6 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 1431-7125 BN 3-540-64034-7 J9 NATO ASI SER SER I PY 1998 VL 55 BP 131 EP 140 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA BM47T UT WOS:000078857000010 ER PT J AU Mullen, J Adam, G Blowers, A Farle, E AF Mullen, J Adam, G Blowers, A Farle, E TI Biolistic transfer of large DNA fragments to tobacco cells using YACs retrofitted for plant transformation SO MOLECULAR BREEDING LA English DT Article DE map-based cloning; plant transformation; retrofitted yeast artificial chromosomes ID DISEASE RESISTANCE GENE; SELECTABLE MARKERS; PROTEIN; CHROMOSOMES; TOMATO; YEAST AB To determine whether large DNA molecules could be transferred and integrated intact into the genome of plant cells, we bombarded tobacco suspension cells with yeast DNA containing artificial chromosomes (YACs) having sizes of 80, 150, 210, or 550 kilobases (kb). Plant selectable markers were retrofitted on both YAC arms so that recovery of each arm in transgenic calli could be monitored. Stably transformed calli resistant to kanamycin (300 mg/L) were recovered for each size of YAC tested. Two Of 12 kanamycin-resistant transformants for the 80 kb YAC and 8 of 29 kanamycin-resistant transformants for the 150 kb YAC also contained a functional hygromycin gene derived from the opposite YAC arm. Southern analyses using probes that spanned the entire 55 kb insert region of the 80 kb YAC confirmed that one of the two double-resistant lines had integrated a fully intact single copy of the YAC DNA while the other contained a major portion of the insert. Transgenic lines that contained only one selectable marker gene from the 80 kb YAC incorporated relatively small portions of the YAC insert DNA distal to the selectable marker. Our data suggest genomic DNA cloned in artificial chromosomes up to 150 kb in size have a reasonable likelihood of being transferred by biolistic methods and integrated intact into the genome of plant cells. Biolistic transfer of YAC DNA may accelerate the isolation of agronomically useful plant genes using map-based cloning strategies. C1 Cornell Univ, NSF, USDA, DOE,Plant Sci Ctr, Ithaca, NY 14853 USA. Sanford Sci Inc, Waterloo, NY 13165 USA. Cornell Univ, Dept Plant Breeding, Ithaca, NY 14853 USA. RP Pioneer HiBred Int Inc, 7300 NW 62nd Ave,POB 1004, Johnston, IA 50131 USA. NR 20 TC 13 Z9 14 U1 0 U2 4 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1380-3743 EI 1572-9788 J9 MOL BREEDING JI Mol. Breed. PY 1998 VL 4 IS 5 BP 449 EP 457 DI 10.1023/A:1009646004272 PG 9 WC Agronomy; Plant Sciences; Genetics & Heredity; Horticulture SC Agriculture; Plant Sciences; Genetics & Heredity GA 127DJ UT WOS:000076335000007 ER PT J AU Risser, SM Wolfgang, J Ferris, KF AF Risser, Steven M. Wolfgang, John Ferris, Kim F. TI N-State Interpretations of the First and Second Hyperpolarizabilities of Cyanobiphenyl-Based Liquid Crystal Molecules SO MOLECULAR CRYSTALS AND LIQUID CRYSTALS SCIENCE AND TECHNOLOGY SECTION A-MOLECULAR CRYSTALS AND LIQUID CRYSTALS LA English DT Article DE Liquid crystals; hyperpolarizability; electronic structure; cyanobiphenyl molecules AB Electronic structure calculations on the frequency-dependent hyperpolarizabilities of 5-alkyl cyanobiphenyl have been performed using the AM1 Hamiltonian and time dependent Hartree-Fock theory. Both the average first and second hyperpolarizabilities decrease with increasing twist angle, O, between the two phenyl groups, and increase with increasing incident frequency. While the nonlinear optical properties of materials are frequently interpreted within the framework of two and three state models for the electronic spectrum, systems with a more complex electronic structure require an approach which can denote state importance. The linear optical properties of 5CB are dominated by two low-lying charge transfer transitions from the ground state, which would seem suitable to a three state model. However, large state dipole moments offset of low oscillator strengths for other transitions allowing them to also become significant contributors to the nonlinear optical properties. C1 [Risser, Steven M.; Wolfgang, John] Texas A&M Univ, Dept Phys, Commerce, TX 75429 USA. [Ferris, Kim F.] Pacific NW Natl Lab, Dept Chem & Mat Sci, Richland, WA 99352 USA. RP Risser, SM (reprint author), Texas A&M Univ, Dept Phys, Commerce, TX 75429 USA. FU U.S. Department of Energy [DE-AC0676RLO 1830] FX The Pacific Northwest National Laboratory is operated by Battelle Memorial Institute for the U.S. Department of Energy under contract DE-AC0676RLO 1830. KFF gratefully acknowledges the support of the Office of Basic Energy Sciences, Materials Sciences Division. JW and SMR acknowledge the support of the Organized Research Program at Texas A & M University-Commerce. NR 25 TC 3 Z9 3 U1 0 U2 0 PU GORDON BREACH PUBLISHING, TAYLOR & FRANCIS GROUP PI PHILADELPHIA PA 325 CHESTNUT ST, 8TH FL, PHILADELPHIA, PA 19106 USA SN 1058-725X J9 MOL CRYST LIQ CRYS A JI Mol. Cryst. Liq. Cryst. Sci. Technol. Sect. A-Mol. Cryst. Liq. Cryst. PY 1998 VL 309 BP 133 EP 142 AR PII 757826616 DI 10.1080/10587259808045524 PG 10 WC Crystallography SC Crystallography GA V04UB UT WOS:000207082200014 ER PT S AU Scott-Craig, JS Apel-Birkhold, PC Gorlach, JM Nikolskaya, A Pitkin, JW Ransom, RF Sposato, P Ahn, JH Tonukari, NJ Wegener, S Walton, JD AF Scott-Craig, JS Apel-Birkhold, PC Gorlach, JM Nikolskaya, A Pitkin, JW Ransom, RF Sposato, P Ahn, JH Tonukari, NJ Wegener, S Walton, JD BE Kohmoto, K Yoder, OC TI Cell wall degrading enzymes in HST-producing fungal pathogens SO MOLECULAR GENETICS OF HOST-SPECIFIC TOXINS IN PLANT DISEASES SE DEVELOPMENTS IN PLANT PATHOLOGY LA English DT Proceedings Paper CT 3rd Tottori International Symposium on Host-Specific Toxins CY AUG 24-29, 1997 CL DAISEN, JAPAN AB Although best known for elaboration of a host-specific toxin, HC-toxin, the fungal maize pathogen Cochliobolus carbonum also produces a large number of cell wall degrading enzymes (CWDEs) capable of depolymerizing various components of the host cell wall. C carbonum genes have been cloned that encode endopolygalacturonase, exo-polygalacturonase, pectin methylesterase, four endo-xylanases, beta-xylosidase, cellobiohydrolase, endo-beta-1,4 glucanase, two exo-beta-1,3-glucanases, two beta-1,3-1,4 glucanases, two alkaline proteases and cutinase. Using a transformation-mediated gene disruption strategy, many of these genes have been mutated singly in pathogenic wild-type C, carbonum strains. In every case, the disruption of the CWDE gene and the concomitant loss of CWDE activity did not cause any detectable change in the pathogenicity or virulence of the mutant strain. Strains of C. carbonum that contain multiple mutations in related CWDEs are being constructed in order to examine whether the inability to degrade a particular cell wall component will affect disease development. C1 Michigan State Univ, DOE, Plant Res Lab, E Lansing, MI 48824 USA. RP Scott-Craig, JS (reprint author), Michigan State Univ, DOE, Plant Res Lab, E Lansing, MI 48824 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0929-1318 BN 0-7923-4981-4 J9 DEV PLANT PATHOL PY 1998 VL 13 BP 245 EP 252 PG 8 WC Agronomy; Biochemistry & Molecular Biology; Plant Sciences SC Agriculture; Biochemistry & Molecular Biology; Plant Sciences GA BL57D UT WOS:000075908700027 ER PT S AU Holbrook, SR AF Holbrook, SR BE Leontis, NB SantaLucia, J TI Crystallographic studies of RNA internal loops SO MOLECULAR MODELING OF NUCLEIC ACIDS SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Molecular Modeling of Nucleic Acids, at the 213th National Meeting of the American-Chemical-Society CY APR 13-17, 1997 CL SAN FRANCISCO, CALIFORNIA SP Amer Chem Soc, Div Comp Chem ID CRYSTAL-STRUCTURE; DOUBLE HELIX; BASE-PAIRS; HAMMERHEAD RIBOZYME; A-SITE; BINDING; RECOGNITION; PRINCIPLES; DOMAIN; ATP AB Internal loops are common and ubiquitous elements of RNA secondary structure. They often form binding sites for metals, proteins, and other RNAs. To understand the effects of internal loops on RNA structure and function, we have determined the crystal and molecular structures of several RNA oligomers which include symmetric internal loops in the double helices formed in the crystal. The internal loops formed by these RNA oligomers generally continue the A-form double helices through formation of non-standard base pairs. Water and divalent metal ions are important for stabilization of some of these non-Watson-Crick base pairs. The distortion from a standard A-RNA helix both within the internal loop and propagated to the surrounding Watson-Crick duplexes varies dramatically depending on the internal loop sequence. The symmetric internal loops observed in these oligomers are compared to the asymmetric internal loops observed in the crystal structure of the P4-P6 domain of the group I catalytic intron. Our limited database is already suggesting improvements in RNA structure prediction algorithms and is providing the basis for comparative model building using phylogenetic information contained hi the RNA sequence databases. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Struct Biol Div, Berkeley, CA 94720 USA. RP Holbrook, SR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Struct Biol Div, Melvin Calvin Bldg, Berkeley, CA 94720 USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3541-4 J9 ACS SYM SER PY 1998 VL 682 BP 56 EP 76 PG 21 WC Chemistry, Multidisciplinary SC Chemistry GA BK18A UT WOS:000071431600004 ER PT S AU Miller, J Cooney, M Miaskiewicz, K Osman, R AF Miller, J Cooney, M Miaskiewicz, K Osman, R BE Leontis, NB SantaLucia, J TI Modeling duplex DNA oligonucleotides with modified pyrimidine bases SO MOLECULAR MODELING OF NUCLEIC ACIDS SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Molecular Modeling of Nucleic Acids, at the 213th National Meeting of the American-Chemical-Society CY APR 13-17, 1997 CL SAN FRANCISCO, CALIFORNIA SP Amer Chem Soc, Div Comp Chem ID MOLECULAR-DYNAMICS SIMULATIONS; THYMINE GLYCOL LESIONS; PARTICLE MESH EWALD; POLYMERASE-I; IONIZING-RADIATION; MAGNETIC-RESONANCE; THYMIDINE GLYCOL; CIS-SYN; DAMAGE; DIMER AB An approach to modeling the structure of modified nucleic acids that combines quantum-chemical calculations with molecular dynamics (MD) simulation is illustrated by studies of DNA oligonucleotides containing pyrimidine base damage. For all of the lesions studied thus far, we have found the most stable stereoisomer to be energetically well separated from other possible lesion configurations. This fact coupled with the large number of conformational degrees of freedom in duplex DNA means that the equilibrium conformations of lesions in an oligonucleotide do not differ greatly from their conformations in isolation. MD simulations of damaged oligonucleotides with explicit inclusion of water and counterions as well as accurate calculation of the electrostatic potential energy generally show that major deviations from the B-DNA conformation are localized to the immediate neighborhood of the damaged site and mainly reflect adaptation of the native DNA conformation to the most energetically favored configuration of the lesion in isolation. C1 Pacific NW Lab, Mol Biosci Dept, Richland, WA 99352 USA. DASGrp Inc, Johnstown, PA 15905 USA. CUNY Mt Sinai Sch Med, Dept Physiol & Biophys, New York, NY 10029 USA. RP Miller, J (reprint author), Pacific NW Lab, Mol Biosci Dept, 902 Battelle Blvd,MS 7-56, Richland, WA 99352 USA. NR 54 TC 2 Z9 2 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3541-4 J9 ACS SYM SER PY 1998 VL 682 BP 312 EP 328 PG 17 WC Chemistry, Multidisciplinary SC Chemistry GA BK18A UT WOS:000071431600019 ER PT J AU Herrera, JN Blum, L Cummings, PT AF Herrera, JN Blum, L Cummings, PT TI Thermodynamic properties of an asymmetric fluid mixture with adhesive hard sphere Yukawa interaction in the mean spherical approximation SO MOLECULAR PHYSICS LA English DT Article ID ORNSTEIN-ZERNIKE EQUATION; INTEGRAL-EQUATION; CLOSURE; STATE; ELECTROLYTES; SYSTEM; LIQUID; MODEL; TAIL AB The analytical solution of the Ornstein-Zernike equation in the mean-spherical approximation for a Yukawa fluid and adhesive hard sphere Yukawa fluid with factorizable coefficients is used to derive a simple form for the thermodynamic properties for both mixtures. The second system contains an additional interaction. However, the general thermodynamic expressions were obtained in similar form for both systems. Some particular cases are discussed in terms of Gamma, the principal parameter to be calculated for these systems. These results complement the recent work of Yasutomi, M., and Ginoza, M., 1996, Molec. Phys., 89, 1755. C1 Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Univ Puerto Rico, Dept Phys, Rio Piedras, PR 00931 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Benemerita Univ Autonoma Puebla, Fac Ciencias Fisicomatemat, Puebla 72001, Mexico. RP Herrera, JN (reprint author), Univ Tennessee, Dept Chem Engn, 419 Dougherty Engn Bldg, Knoxville, TN 37996 USA. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 30 TC 6 Z9 6 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD JAN PY 1998 VL 93 IS 1 BP 73 EP 78 DI 10.1080/002689798169447 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YT699 UT WOS:000071634200007 ER PT J AU Cui, ST Cummings, PT Cochran, HD AF Cui, ST Cummings, PT Cochran, HD TI The calculation of viscosity of liquid n-decane and n-hexadecane by the Green-Kubo method SO MOLECULAR PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS; SIMULATIONS; FLUIDS AB This short commentary presents the result of long molecular dynamics simulation calculations of the shear viscosity of liquid n-decane and n-hexadecane using the Green-Kubo integration method. The relaxation time of the stress-stress correlation function is compared with those of rotation and diffusion. The rotational and diffusional relaxation times, which are easy to calculate, provide useful guides for the required simulation time in viscosity calculations. Also, the computational time required for viscosity calculations of these systems by the Green-Kubo method is compared with the time required for previous non-equilibrium molecular dynamics calculations of the same systems. The method of choice for a particular calculation is determined largely by the properties of interest, since the efficiencies of the two methods are comparable for calculation of the zero strain rate viscosity. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. RP Cui, ST (reprint author), Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 14 TC 25 Z9 25 U1 0 U2 10 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD JAN PY 1998 VL 93 IS 1 BP 117 EP 121 DI 10.1080/002689798169500 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YT699 UT WOS:000071634200013 ER PT B AU Nieh, TG Wadsworth, J AF Nieh, TG Wadsworth, J BE Crowson, A Chen, ES Shields, JA Subramanian, PR TI Improved understanding of the mechanical behavior of molybdenum alloys at elevated temperatures SO MOLYBDENUM AND MOLYBDENUM ALLOYS LA English DT Proceedings Paper CT TMS Symposium on Molybdenum and Molybdenum Alloys at the 127th Annual Meeting and Exhibition of the Minerals-Metals-and-Materials-Society CY FEB 16-19, 1998 CL SAN ANTONIO, TX SP TMS Refractory Met Comm AB In the present paper, the high temperature deformation behavior of Mo-based alloys is discussed. Recent experiments have shown that Mo alloys (e.g. Mo-Nb, Mo-Re) deformed at elevated temperatures exhibit some characteristics of Class I alloys: a stress exponent of 3, a moderate to large elongation, little to no primary creep or inversion of primary creep, and sample necking down to a point. Theoretical considerations for Class I alloys, in particular for Mo-based alloys, are also given. It is shown that relatively large atomic size mismatches tend to characterize Class I solid solution alloys, but this is not a consistent guideline for the prediction of Class I solid solution behavior in Mo alloys. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Nieh, TG (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-369,POB 808, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-411-9 PY 1998 BP 89 EP 97 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science; Metallurgy & Metallurgical Engineering GA BM05V UT WOS:000077533600007 ER PT B AU Chen, SR Maudlin, PJ Gray, GT AF Chen, SR Maudlin, PJ Gray, GT BE Crowson, A Chen, ES Shields, JA Subramanian, PR TI Mechanical properties and constitutive relations for molybdenum under high-rate deformation SO MOLYBDENUM AND MOLYBDENUM ALLOYS LA English DT Proceedings Paper CT TMS Symposium on Molybdenum and Molybdenum Alloys at the 127th Annual Meeting and Exhibition of the Minerals-Metals-and-Materials-Society CY FEB 16-19, 1998 CL SAN ANTONIO, TX SP TMS Refractory Met Comm AB Molybdenum and its alloys have received increased interest in recent years for ballistic applications. The stress-strain behavior of several molybdenums possessing various compositions, manufacturing sources, and the degree of pre-straining, were investigated as a function of temperature from 77 to 1273K, and strain rate from 10(-3)s(-1) to 8000s(-1). The yield stress was found to be sensitive to the test temperature and strain rate, however, the strain hardening remained rate-insensitive. The constitutive response of a powder-metallurgy molybdenum was also investigated; similar mechanical properties compared to conventionally wrought processed molybdenums were achieved. Constitutive relations based upon the Johnson-Cook, the Zerilli-Armstrong and the Mechanical Threshold Stress (MTS) models were evaluated and fit for the various Mo-based materials. The capabilities and limitations of each model for large-strain applications were examined. The differences between the three models are demonstrated using model comparisons to Taylor cylinder validation experiments. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Chen, SR (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 5 Z9 5 U1 0 U2 4 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-411-9 PY 1998 BP 155 EP 172 PG 18 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science; Metallurgy & Metallurgical Engineering GA BM05V UT WOS:000077533600012 ER PT B AU Stephens, JJ Damkroger, BK Ewsuk, KG Glass, SJ Monroe, SL Reece, M Smugeresky, JE AF Stephens, JJ Damkroger, BK Ewsuk, KG Glass, SJ Monroe, SL Reece, M Smugeresky, JE BE Crowson, A Chen, ES Shields, JA Subramanian, PR TI A study of Mo-V and Mo-V-Fe alloys for conductive cermet applications SO MOLYBDENUM AND MOLYBDENUM ALLOYS LA English DT Proceedings Paper CT TMS Symposium on Molybdenum and Molybdenum Alloys at the 127th Annual Meeting and Exhibition of the Minerals-Metals-and-Materials-Society CY FEB 16-19, 1998 CL SAN ANTONIO, TX SP TMS Refractory Met Comm AB Molybdenum/alumina cermets are currently being used for small, simple geometry, electrical feed-throughs in insulating alumina ceramic bodies. However, with larger and more complex geometries, high residual stresses and cracking of the alumina ceramic occur due to differences in coefficient of thermal expansion (CTE) between cermet and the surrounding 94% alumina. The difference in CTE is caused by the Mo in the cermet, which lowers the CTE of the cermet relative to the 94% alumina ceramic. A study was conducted at Sandia National Laboratories to develop CTE-matched cermets based on binary Mo-V and ternary Mo-V-X alloy systems. It was found that the CTE of 94% alumina (over the range 1000 degrees C to room temperature) could be precisely matched by a binary Mo-32.5V alloy. However, to address concerns regarding the selective oxidation of V, Mo-V-X alloys with CTE's similar to 94% alumina were made with Fe or Co additions. The ternary additions are limited to about 3 wt.% to maintain a single phase BCC alloy, and permit some reduction in the V addition. Powders were :fabricated from both Mo-27V and Mo-22V-3Fe, and were evaluated in 3 hr./1625 degrees C cermet sintering trials. The results of those trials suggest that extensive reaction occurs between the Vanadium component of the alloy and the alumina ceramic. In view of these results we have begun to evaluate the feasibility of fabricating Iridium/alumina cermets. Iridium is an attractive choice due to its close CTE match to 94% alumina ceramic. Preliminary results indicate there is no detrimental reaction between the Iridium and alumina phases. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Stephens, JJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-411-9 PY 1998 BP 205 EP 220 PG 16 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science; Metallurgy & Metallurgical Engineering GA BM05V UT WOS:000077533600016 ER PT S AU Lochter, A Sternlicht, MD Werb, Z Bissell, MJ AF Lochter, A Sternlicht, MD Werb, Z Bissell, MJ BE Fleischmajer, R Timpl, R Werb, Z TI The significance of matrix metalloproteinases during early stages of tumor progression SO MORPHOGENESIS: CELLULAR INTERACTIONS SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Morphogenesis - Cellular Interactions CY OCT 20-23, 1997 CL BETHESDA, MARYLAND SP New York Acad Sci, March Dimes Birth Defects Fdn, Natl Inst Child Hlth & Human Dev, Council Tobacco Res, USA Inc, Fdn Basic Cutaneous Res, Genome Therapeut Corp, Ontogeny Inc, Orentreich Fdn Advancement Sci Inc ID TRANSGENIC MICE; EXTRACELLULAR-MATRIX; NEURITE OUTGROWTH; MOUSE SKIN; GENE-EXPRESSION; GROWTH-FACTOR; COLLAGENASE EXPRESSION; PROTEASE INHIBITORS; BASEMENT-MEMBRANE; IV COLLAGENASE AB Matrix metalloproteinases (MMPs) orchestrate tissue remodeling and play diverse roles during organ development. They are produced excessively during the course of various pathological conditions, including solid tumors. An important function Elf MMPs during tumor progression is to provide the proteolytic activity that is necessary both for tumor cells to invade extracellular matrix (ECM) and for neovascularization of tumor tissue by endothelial cells. Recently, independent studies in transgenic animals suggest that MMPs may, in addition, promote very early stages of tumor progression. To investigate this possibility further, we have analyzed the consequences of MMP overexpression in functionally normal and nontumorigenic mouse mammary epithelial cells in culture. Our observations demonstrate that the MMP stromelysin-l (SL-I) triggers an epigenetic molecular program in mammary epithelial cells that results in a number of phenotypic alterations that eventually culminate in the generation of a malignant tumor-cell phenotype. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif San Francisco, Dept Anat, San Francisco, CA 94143 USA. RP Bissell, MJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. FU NCI NIH HHS [CA 57621]; NIEHS NIH HHS [5T32 ES07106] NR 54 TC 89 Z9 91 U1 0 U2 3 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-131-6 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1998 VL 857 BP 180 EP 193 DI 10.1111/j.1749-6632.1998.tb10116.x PG 14 WC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Multidisciplinary Sciences SC Biochemistry & Molecular Biology; Cell Biology; Developmental Biology; Science & Technology - Other Topics GA BL93V UT WOS:000077211500015 PM 9917841 ER PT J AU Sales, BC AF Sales, BC TI Electron crystals and phonon glasses: A new path to improved thermoelectric materials SO MRS BULLETIN LA English DT Article ID THERMAL-CONDUCTIVITY; LAFE4P12 STRUCTURE; METAL PHOSPHIDES; TEMPERATURE; EARTH; SUPERCONDUCTIVITY; SKUTTERUDITES; ANTIMONIDES; PRESSURE C1 Oak Ridge Natl Lab, Div Solid State, Novel Mat Grp, Oak Ridge, TN 37831 USA. RP Sales, BC (reprint author), Oak Ridge Natl Lab, Div Solid State, Novel Mat Grp, Oak Ridge, TN 37831 USA. NR 37 TC 81 Z9 82 U1 6 U2 22 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD JAN PY 1998 VL 23 IS 1 BP 15 EP 21 PG 7 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA YY318 UT WOS:000072135100012 ER PT J AU Auciello, O Gruverman, A Tokumoto, H Prakash, SA Aggarwal, S Ramesh, R AF Auciello, O Gruverman, A Tokumoto, H Prakash, SA Aggarwal, S Ramesh, R TI Nanoscale scanning force imaging of polarization phenomena in ferroelectric thin films SO MRS BULLETIN LA English DT Article ID DOMAIN-STRUCTURE; MICROSCOPY; SURFACE; CONTRAST; SULFATE; TIME C1 Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. N Carolina State Univ, Dept Mat Sci, Raleigh, NC 27695 USA. Sony Corp, Res Ctr, Hodogaya Ku, Yokohama, Kanagawa 240, Japan. Univ Maryland, Dept Mat Sci & Nucl Engn, College Pk, MD 20742 USA. RP Auciello, O (reprint author), Argonne Natl Lab, Div Sci Mat, 212 C210,9700 S Cass Ave, Argonne, IL 60439 USA. EM orlando_auciello@qmgate.anl.gov; alexei@src.sony.co.jp; htokumot@nair.go.jp; prak@eng.umd.edu; aggarwal@eng.umd.edu; rr136@umail.umd.edu RI Gruverman, alexei/P-3537-2014 OI Gruverman, alexei/0000-0003-0492-2750 NR 32 TC 76 Z9 76 U1 4 U2 12 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD JAN PY 1998 VL 23 IS 1 BP 33 EP 42 PG 10 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA YY318 UT WOS:000072135100015 ER PT J AU Knobloch, K Perlin, P Krueger, J Weber, ER Kisielowski, C AF Knobloch, K Perlin, P Krueger, J Weber, ER Kisielowski, C TI Effect of internal absorption on cathodoluminescence from GaN SO MRS INTERNET JOURNAL OF NITRIDE SEMICONDUCTOR RESEARCH LA English DT Article ID ELECTRON-ENERGY DISSIPATION; KILOVOLT AB We have studied optical properties of GaN grown on sapphire by metalorganic chemical vapor deposition in the near band-edge energy range by cathodoluminescence. A large shift of the band-edge luminescence to lower energies is induced by increasing the beam energy. The free exciton position shifts about 20 meV when the beam energy is increased from 5 keV to 25 keV at room-temperature. The effect is explained by internal absorption caused by an exponential absorption tail at the band-edge. An Urbach parameter of about 30 to 40 meV for the exponential band-tail in our samples is estimated by comparing experimental with simulated spectra. C1 Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. RP Knobloch, K (reprint author), Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. NR 12 TC 37 Z9 37 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 1092-5783 J9 MRS INTERNET J N S R JI Mrs. Internet J. Nitride Semicond. Res. PY 1998 VL 3 IS 3-4 BP art. no. EP 4 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA YZ335 UT WOS:000072244100002 ER PT J AU Cho, H Hong, J Maeda, T Donovan, SM MacKenzie, JD Abernathy, CR Pearton, SJ Shul, RJ Han, J AF Cho, H Hong, J Maeda, T Donovan, SM MacKenzie, JD Abernathy, CR Pearton, SJ Shul, RJ Han, J TI New plasma chemistries for etching GaN and InN: BI3 and BBr3 SO MRS INTERNET JOURNAL OF NITRIDE SEMICONDUCTOR RESEARCH LA English DT Article ID III-V NITRIDES; CL-2/AR; CH4/H-2/AR; DIODES; ALN AB Smooth, anisotropic etching of InN and GaN is obtained in BI3- or BBr3-based Inductively Coupled Plasmas. Etch selectivities of 100:1 were achieved for InN over both GaN and AlN in the BI3 mixtures, while for BBr3 discharges values of 100:1 for InN over AlN and 25:1 for InN over GaN were measured. The etched surface morphologies of InN and GaN with both mixtures are similar or better than those of control samples. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Fujitsu Labs Ltd, Atsugi, Kanagawa 24301, Japan. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Cho, H (reprint author), Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. NR 18 TC 11 Z9 11 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 1092-5783 J9 MRS INTERNET J N S R JI Mrs. Internet J. Nitride Semicond. Res. PY 1998 VL 3 IS 5 AR 5 PG 17 WC Materials Science, Multidisciplinary SC Materials Science GA ZA200 UT WOS:000072338900001 ER PT J AU Ren, F Abernathy, CR Van Hove, JM Chow, PP Hickman, R Klaasen, JJ Kopf, RF Cho, H Jung, KB La Roche, JR Wilson, RG Han, J Shul, RJ Baca, AG Pearton, SJ AF Ren, F Abernathy, CR Van Hove, JM Chow, PP Hickman, R Klaasen, JJ Kopf, RF Cho, H Jung, KB La Roche, JR Wilson, RG Han, J Shul, RJ Baca, AG Pearton, SJ TI 300 degrees C GaN/AlGaN heterojunction bipolar transistor SO MRS INTERNET JOURNAL OF NITRIDE SEMICONDUCTOR RESEARCH LA English DT Article ID CHARGE; GAN; DEVICES; FIELD AB A GaN/AlGaN heterojunction bipolar transistor has been fabricated using Cl-2/Ar dry etching for mesa formation. As the hale concentration increases due to more efficient ionization of the Mg accepters at elevated temperatures (> 250 degrees C), the device shows improved gain. Future efforts should focus on methods for reducing base resistance, which are briefly summarized. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. AT&T Bell Labs, Lucent Technol, Naperville, IL 60566 USA. Charles Evans & Associates, Redwood City, CA USA. Sandia Natl Labs, Albuquerque, NM USA. RP Ren, F (reprint author), Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. NR 18 TC 62 Z9 62 U1 1 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 1092-5783 J9 MRS INTERNET J N S R JI Mrs. Internet J. Nitride Semicond. Res. PY 1998 VL 3 IS 41 AR 41 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 130WY UT WOS:000076544400001 ER PT B AU Ashwood, TL Sample, BE Washington-Allen, RA Suter, GW AF Ashwood, TL Sample, BE Washington-Allen, RA Suter, GW BE ElSwaify, SA Yakowitz, DS TI An integrated approach to ecological risk assessment of a large forested ecosystem SO MULTIPLE OBJECTIVE DECISION MAKING FOR LAND, WATER AND ENVIRONMENTAL MANAGEMENT LA English DT Proceedings Paper CT 1st International Conference on Multiple Objective Decision Support Systems (MODSS) for Land, Water, and Environmental Management - Concepts, Approaches, and Applications CY SEP, 1996 CL HONOLULU, HI SP World Assoc Soil & Water Conservat, Soil & Water Conservat Soc, Int Chapter, Int Soc Soil Sci, Int Soc Multiple Criteria Decis Making, Univ Hawaii, USDA ARS SW Watershed Res Ctr, East West Ctr, Oak Ridge Natl Lab, USDA Forest Serv, Queensland Dept Primary Ind, Inst Nacl Investigac Forestales & Agropecuarias, Univ Arizona C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU LEWIS PUBLISHERS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, BOCA RATON, FL 33431 USA BN 1-57444-091-8 PY 1998 BP 121 EP 132 PG 12 WC Agronomy; Environmental Sciences; Environmental Studies; Planning & Development; Water Resources SC Agriculture; Environmental Sciences & Ecology; Public Administration; Water Resources GA BK51C UT WOS:000072399800010 ER PT B AU Carnes, SA Reed, RM AF Carnes, SA Reed, RM BE ElSwaify, SA Yakowitz, DS TI Lessons learned and new challenges for integrated assessment under the National Environmental Policy Act SO MULTIPLE OBJECTIVE DECISION MAKING FOR LAND, WATER AND ENVIRONMENTAL MANAGEMENT LA English DT Proceedings Paper CT 1st International Conference on Multiple Objective Decision Support Systems (MODSS) for Land, Water, and Environmental Management - Concepts, Approaches, and Applications CY SEP, 1996 CL HONOLULU, HI SP World Assoc Soil & Water Conservat, Soil & Water Conservat Soc, Int Chapter, Int Soc Soil Sci, Int Soc Multiple Criteria Decis Making, Univ Hawaii, USDA ARS SW Watershed Res Ctr, East West Ctr, Oak Ridge Natl Lab, USDA Forest Serv, Queensland Dept Primary Ind, Inst Nacl Investigac Forestales & Agropecuarias, Univ Arizona AB One of the first government-sponsored demands for integrated assessment to support decision making in the U.S. is embodied in the National Environmental Policy Act of 1969 (NEPA). Over the past 25 years, the Oak Ridge National Laboratory (ORNL) has supported federal agencies in evaluating health and environmental impacts as required by NEPA. Many of ORNL's efforts have focused on complex, programmatic assessments that break new ground and require and integrate expertise from a wide Examples of ORNL projects that illustrate the use of integrated assessment approaches include environmental documentation for: (1) the Department of the Army's Chemical Stockpile Disposal Program, (2) the Federal Energy Regulatory Commission's licensing activities related to the Owens River Basin in eastern California and along a 500-mi reach of the upper Ohio River, and (3) the Nuclear Regulatory Commission's decision regarding restart of the undamaged reactor (Unit 1) at Three Mile Island. Our discussion of these examples illustrates successful integrated assessment approaches and identifies new challenges facing integrated assessment activities. C1 Oak Ridge Natl Lab, Div Energy, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LEWIS PUBLISHERS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, BOCA RATON, FL 33431 USA BN 1-57444-091-8 PY 1998 BP 541 EP 555 PG 15 WC Agronomy; Environmental Sciences; Environmental Studies; Planning & Development; Water Resources SC Agriculture; Environmental Sciences & Ecology; Public Administration; Water Resources GA BK51C UT WOS:000072399800046 ER PT J AU Lillo, TM Korth, GE AF Lillo, TM Korth, GE TI Consolidation of nanocrystalline Fe-1.6 wt%C via low temperature hot isostatic pressing SO NANOSTRUCTURED MATERIALS LA English DT Article ID MECHANICAL-PROPERTIES; GRAIN-GROWTH; CERAMICS; POWDERS; TIO2 AB Ball-milled Fe-1.6 wt% C powder with a nanocrystalline substructure was consolidated to fill density via hot isostatic pressing at 500 degrees C and 414 MPa. The HIPped microstructure remained largely nanocrystalline (similar to 39 nm in diameter). Although the grain size increased, the grain size distribution was not significantly altered. The results of this study suggest that other nanocrystalline materials in powder form may be consolidated via HIPping at temperatures low enough to prevent extensive grain growth. (C) 1998 Acta Metallurgica Inc. C1 Lockheed Martin Idaho Technol, Idaho Falls, ID 83415 USA. RP Lillo, TM (reprint author), Lockheed Martin Idaho Technol, POB 1625, Idaho Falls, ID 83415 USA. RI Lilllo, Thomas/S-5031-2016 OI Lilllo, Thomas/0000-0002-7572-7883 NR 22 TC 12 Z9 13 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PD JAN PY 1998 VL 10 IS 1 BP 35 EP 43 DI 10.1016/S0965-9773(98)00028-2 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA ZQ271 UT WOS:000073840600004 ER PT J AU Alexandrov, IV Zhu, YT Lowe, TC Islamgaliev, RK Valiev, RZ AF Alexandrov, IV Zhu, YT Lowe, TC Islamgaliev, RK Valiev, RZ TI Consolidation of nanometer sized powders using severe plastic torsional straining SO NANOSTRUCTURED MATERIALS LA English DT Article ID NANOCRYSTALLINE MATERIALS; MECHANICAL ATTRITION; NANOPHASE TIO2; BEHAVIOR; ALLOY AB Severe Plastic Deformation (SPD) via torsional straining was used to consolidate nanometer-sized metallic powders and metal-ceramic nanocomposites at room temperature. Materials processed using this technique included copper, Al and nanocomposites based on these metallic nanopowders and SiO2, SiC and Al2O3 nanopowders. The as-processed materials were nearly fully dense. Transmission electron microscopy (TEM) and microhardness measurements were used to characterize the materials. The as-consolidated materials had a grain size smaller than the average particle size of starting powder, indicating grain refinement during severe plastic torsional straining. Due to the oxidation of the initial nanometer sized powders, the as-processed samples were very brittle. Thermal stability was investigated by annealing the as-consolidated samples at various temperatures and then measuring their microhardness. (C) 1998 Acta Metallurgica Inc. C1 Ufa State Aviat Tech Univ, Inst Phys Adv Mat, Ufa 450000, Russia. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Alexandrov, IV (reprint author), Ufa State Aviat Tech Univ, Inst Phys Adv Mat, K Marksa 12, Ufa 450000, Russia. RI Zhu, Yuntian/B-3021-2008 OI Zhu, Yuntian/0000-0002-5961-7422 NR 33 TC 66 Z9 72 U1 2 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0965-9773 J9 NANOSTRUCT MATER JI Nanostruct. Mater. PD JAN PY 1998 VL 10 IS 1 BP 45 EP 54 DI 10.1016/S0965-9773(98)00026-9 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA ZQ271 UT WOS:000073840600005 ER PT S AU Hill, KM Martin, JE Adolf, DA AF Hill, KM Martin, JE Adolf, DA BE Beaucage, G Mark, JE Burns, GT Hua, DW TI Rheology of colloidal suspensions and its implication for tank waste processing SO NANOSTRUCTURED POWDERS AND THEIR INDUSTRIAL APPLICATIONS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Nanostructured Powders and Their Industrial Applications CY APR 13-15, 1998 CL SAN FRANCISCO, CA SP Dow Corning Corp, Midland, Michigan, Millennium Inorgan Chem, Baltimore, Maryland, Univ Cincinnati, Cincinnati, Ohio AB The rheology of colloidal suspensions can vary enormously depending on the contents of the suspensions and the details of how they were produced. Certain interactions between particles within colloidal suspensions can greatly affect their rheology which can be a serious impediment to their processing. For example, at DOE's Hanford site, the radioactive tank wastes are very concentrated and have formed a sludge that is too viscous to process. We are interested in understanding the rheology of this system in order to develop an efficient method for processing the waste. Towards this end we have developed a model silica system for the tank wastes whose particles can interact through chemical bonding, Keesom interactions, and Coulombic interactions. Through systematic variation of the solvent and the particle concentration we can alter the rheological behavior from shear thickening to shear thinning to Newtonian. We present preliminary results for this system as it applies to the processing of the tank waste at Hanford. C1 Sandia Natl Labs, Albuquerque, NM 87108 USA. RP Hill, KM (reprint author), Sandia Natl Labs, Albuquerque, NM 87108 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-426-2 J9 MATER RES SOC SYMP P PY 1998 VL 520 BP 51 EP 56 PG 6 WC Engineering, Multidisciplinary; Materials Science, Ceramics; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BL59P UT WOS:000075966500006 ER PT S AU Darab, JG AF Darab, JG BE Beaucage, G Mark, JE Burns, GT Hua, DW TI Production of nano-crystalline zirconia-based powders using a flow-through hydrothermal process SO NANOSTRUCTURED POWDERS AND THEIR INDUSTRIAL APPLICATIONS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Nanostructured Powders and Their Industrial Applications CY APR 13-15, 1998 CL SAN FRANCISCO, CA SP Dow Corning Corp, Midland, Michigan, Millennium Inorgan Chem, Baltimore, Maryland, Univ Cincinnati, Cincinnati, Ohio AB Nano-crystalline, zirconium oxide and oxyhydroxide particulates were produced using a novel, continuous, flow-through hydrothermal technology which was previously developed at the Pacific Northwest National Laboratory. Homogeneous aqueous solutions containing 0.1 M ZrO(NO3)(2), 0.2-0.5M urea, and in some cases 0.025-0.10M NaF were pumped at pressures of 6000-8000 psi through a heated stainless steel reaction tube at 340-350 degrees C. Flow at pressure was maintained using a nozzle at the down-stream end of the reaction tube. In this process, termed Rapid Thermal Decomposition of precursors in Solution (RTDS), the formation of zirconium oxide and oxyhydroxide nano-crystals (diameters of generally less than 15-nm) occurred during the solution's brief residence time (<15 seconds) in the reaction tube, yielding aqueous slurries of agglomerated particulates upon exiting the nozzle. Powders were separated from these slurries, washed, then dried. RTDS powder prepared from 0.1M ZrO(NO3)2 and 0.5M urea had a surface area of 210 m(2)/g and was determined to be a mixture of predominantly nano-crystalline (<10 nm crystallite diameter) cubic ZrO2 with the balance being monoclinic ZrO2. This powder was subsequently calcined to 500 degrees C, pressed into a pellet at 20,000 psi and sintered at 500 degrees C for one hour to yield a mechanically stable porous support with a measured surface area of 125 m(2)/g. In contrast, RTDS powder prepared from 0.1M ZrO(NO3)(2), 0.5M urea, and 0.1M NaF was determined to be pure monoclinic ZrO2 with a surface area of 58 m(2)/g. C1 Battelle Mem Inst, Pacific NW Labs, Richland, WA 99352 USA. RP Darab, JG (reprint author), Battelle Mem Inst, Pacific NW Labs, POB 999,MS K3-59, Richland, WA 99352 USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-426-2 J9 MATER RES SOC SYMP P PY 1998 VL 520 BP 161 EP 166 PG 6 WC Engineering, Multidisciplinary; Materials Science, Ceramics; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BL59P UT WOS:000075966500021 ER PT S AU Matson, DW Darab, JG Brewer, TD Kaviratna, PD AF Matson, DW Darab, JG Brewer, TD Kaviratna, PD BE Beaucage, G Mark, JE Burns, GT Hua, DW TI Production of nanocrystalline sulfated zirconia catalysts via a flow-through hydrothermal process SO NANOSTRUCTURED POWDERS AND THEIR INDUSTRIAL APPLICATIONS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Nanostructured Powders and Their Industrial Applications CY APR 13-15, 1998 CL SAN FRANCISCO, CA SP Dow Corning Corp, Midland, Michigan, Millennium Inorgan Chem, Baltimore, Maryland, Univ Cincinnati, Cincinnati, Ohio AB Nanocrystalline sulfated zirconia catalysts were prepared using the rapid thermal decomposition of precursors in solution (RTDS) powder formation process. Zirconia gel formation, initial crystallization, and sulfate incorporation occurred during a brief exposure to hydrothermal conditions in the RTDS reactor. The partially crystalline zirconia solid was collected as a suspension, separated by centrifugation, and subjected to calcination to achieve full catalytic activity. Crystallinity, sulfate content, and catalytic activity of the calcined powders toward butane isomerization varied according to the hydrothermal conditions at which the zirconia powders were originally precipitated. The powders were characterized using powder XRD, FTIR, and XAS. C1 Battelle Mem Inst, Pacific NW Labs, Richland, WA 99352 USA. RP Matson, DW (reprint author), Battelle Mem Inst, Pacific NW Labs, POB 999, Richland, WA 99352 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-426-2 J9 MATER RES SOC SYMP P PY 1998 VL 520 BP 287 EP 292 PG 6 WC Engineering, Multidisciplinary; Materials Science, Ceramics; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BL59P UT WOS:000075966500036 ER PT S AU Jackson, NB Evans, L Datye, A AF Jackson, NB Evans, L Datye, A BE Parmaliana, A Sanfilippo, D Frusteri, F Vaccari, A Arena, F TI Attrition-determining morphology changes on iron Fischer-Tropsch catalysts SO NATURAL GAS CONVERSION V SE STUDIES IN SURFACE SCIENCE AND CATALYSIS LA English DT Article; Proceedings Paper CT 5th International Natural Gas Conversion Symposium CY SEP 20-25, 1998 CL TAORMINA, ITALY SP Azienda Autonoma Incremento Turist Provincia Messina, Akzo Nobel Chem SpA, Amoco Corp, Banco Sicilia, Engelhard, Eni SpA, Enitechnol SpA, Euro Support Mfg BV, Euron SpA, Haldor Topsoe AS, KTI SpA, Libreria Bonanzinga, Micromeritics SrI, Philips SpA, Presidenza Assemblea Reg Siciliana, Presidenza Governo Reg Siciliana, Provincia Reg Messina, Repsol Petroleo SA, Sasol, Shell, Snam SpA, Snamprogetti SpA, Statoil AS, Sud Chem AG, Thermoquest C E Instruments ID OXIDE CATALYSTS AB Temperature programmed reduction and transmission electron microscopy were used to study the morphology changes of an iron Fischer-Tropsch catalyst during reaction, with an emphasis on potential attrition of the catalyst. In particular, the effect of potassium promotion was explored. Potassium appeared to minimize the formation of one type of carbide and, at low concentrations, limited graphitic carbon formation. At higher potassium levels (3%) graphitic carbon began to re-appear. Copper-promoted catalysts exposed to higher reaction temperatures (which is known to cause attrition) formed different carbides than those exposed to lower reaction temperatures. The potassium promoted catalysts investigated in this study did not produce the high temperature carbide present on catalysts that quickly attritted. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. RP Jackson, NB (reprint author), Sandia Natl Labs, MS 0710,POB 5800, Albuquerque, NM 87185 USA. OI Datye, Abhaya/0000-0002-7126-8659 NR 9 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE PUBL B V PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2991 BN 0-444-82967-9 J9 STUD SURF SCI CATAL PY 1998 VL 119 BP 137 EP 142 PG 6 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA BL85Q UT WOS:000076939000021 ER PT S AU Borry, RW Lu, EC Kim, YH Iglesia, E AF Borry, RW Lu, EC Kim, YH Iglesia, E BE Parmaliana, A Sanfilippo, D Frusteri, F Vaccari, A Arena, F TI Non-oxidative catalytic conversion of methane with continuous hydrogen removal SO NATURAL GAS CONVERSION V SE STUDIES IN SURFACE SCIENCE AND CATALYSIS LA English DT Article; Proceedings Paper CT 5th International Natural Gas Conversion Symposium CY SEP 20-25, 1998 CL TAORMINA, ITALY SP Azienda Autonoma Incremento Turist Provincia Messina, Akzo Nobel Chem SpA, Amoco Corp, Banco Sicilia, Engelhard, Eni SpA, Enitechnol SpA, Euro Support Mfg BV, Euron SpA, Haldor Topsoe AS, KTI SpA, Libreria Bonanzinga, Micromeritics SrI, Philips SpA, Presidenza Assemblea Reg Siciliana, Presidenza Governo Reg Siciliana, Provincia Reg Messina, Repsol Petroleo SA, Sasol, Shell, Snam SpA, Snamprogetti SpA, Statoil AS, Sud Chem AG, Thermoquest C E Instruments ID PROTONIC CONDUCTION; AUTOCATALYSIS; TEMPERATURE AB Simulations predict maximum C-2-C-10 yields of 14% for both homogeneous and surface-initiated CH4 pyrolysis at 1038 K. Yields are limited by thermodynamics, kinetic inhibition by H-2, and carbon formation. Continuous H2 removal from the system can overcome these constraints and increase maximum predicted yields to 88%. CH4 pyrolysis experiments at 950 K on 4 wt% Mo/H-ZSM5 achieves near-equilibrium conversions (10-12%) with >90% C2-C10 selectivity by catalyzing both C2H4 formation from CH4 (on MoOxCy) and C2H4 aromatization (on H+), while restricting chain growth to benzene and naphthalene. An H-transport membrane reactor of dense SrZr0.95Y0.05O3 thin (10-100 mu m) films can be used to overcome these thermodynamic constraints. Self-supporting, thick (1000 mu m) disks were prepared via combustion synthesis methods, which form denser membranes than powders formed via co-precipitation. Membrane reactor experiments using thick SrZr0.95Y0.05O3 disks had H-transport rates insufficient to affect CH4 pyrolysis reactions. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Kunsan Natl Univ, Kunsan 573701, Chonbuk, South Korea. RP Borry, RW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Iglesia, Enrique/D-9551-2017 OI Iglesia, Enrique/0000-0003-4109-1001 NR 20 TC 67 Z9 67 U1 1 U2 23 PU ELSEVIER SCIENCE PUBL B V PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2991 BN 0-444-82967-9 J9 STUD SURF SCI CATAL PY 1998 VL 119 BP 403 EP 410 PG 8 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA BL85Q UT WOS:000076939000065 ER PT S AU Venkataraman, VK Guthrie, HD Avellanet, RA Driscoll, DJ AF Venkataraman, VK Guthrie, HD Avellanet, RA Driscoll, DJ BE Parmaliana, A Sanfilippo, D Frusteri, F Vaccari, A Arena, F TI Overview of US DOE's natural gas-to-liquids RD & D program and commercialization strategy SO NATURAL GAS CONVERSION V SE STUDIES IN SURFACE SCIENCE AND CATALYSIS LA English DT Article; Proceedings Paper CT 5th International Natural Gas Conversion Symposium CY SEP 20-25, 1998 CL TAORMINA, ITALY SP Azienda Autonoma Incremento Turist Provincia Messina, Akzo Nobel Chem SpA, Amoco Corp, Banco Sicilia, Engelhard, Eni SpA, Enitechnol SpA, Euro Support Mfg BV, Euron SpA, Haldor Topsoe AS, KTI SpA, Libreria Bonanzinga, Micromeritics SrI, Philips SpA, Presidenza Assemblea Reg Siciliana, Presidenza Governo Reg Siciliana, Provincia Reg Messina, Repsol Petroleo SA, Sasol, Shell, Snam SpA, Snamprogetti SpA, Statoil AS, Sud Chem AG, Thermoquest C E Instruments C1 US DOE, Fed Energy Technol Ctr, Morgantown, WV USA. US DOE, Off Fossil Energy, Oil Program, Washington, DC USA. US DOE, Off Fossil Energy, Gas Program, Washington, DC USA. RP Venkataraman, VK (reprint author), US DOE, Fed Energy Technol Ctr, Morgantown, WV USA. NR 6 TC 15 Z9 16 U1 0 U2 1 PU ELSEVIER SCIENCE PUBL B V PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2991 BN 0-444-82967-9 J9 STUD SURF SCI CATAL PY 1998 VL 119 BP 913 EP 918 PG 6 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA BL85Q UT WOS:000076939000148 ER PT J AU Perlmutter, S Aldering, G Della Valle, M Deustua, S Ellis, RS Fabbro, S Fruchter, A Goldhaber, G Groom, DE Hook, IM Kim, AG Kim, MY Knop, RA Lidman, C McMahon, RG Nugent, P Pain, R Panagia, N Pennypacker, CR Ruiz-Lapuente, P Schaefer, B Walton, N AF Perlmutter, S Aldering, G Della Valle, M Deustua, S Ellis, RS Fabbro, S Fruchter, A Goldhaber, G Groom, DE Hook, IM Kim, AG Kim, MY Knop, RA Lidman, C McMahon, RG Nugent, P Pain, R Panagia, N Pennypacker, CR Ruiz-Lapuente, P Schaefer, B Walton, N TI Discovery of a supernova explosion at half the age of the Universe SO NATURE LA English DT Article ID IA SUPERNOVAE; COSMOLOGICAL CONSTANT; LIGHT-CURVE AB The ultimate fate of the Universe, infinite expansion or a big crunch, can be determined by using the redshifts and distances of very distant supernovae to monitor changes in the expansion rate, We can now find(1) large numbers of these distant supernovae, and measure their redshifts and apparent brightnesses; moreover, recent studies of nearby type Ia supernovae have shown how to determine their intrinsic luminosities(2-4)-and therefore with their apparent brightnesses obtain their distances, The >50 distant supernovae discovered so far provide a record of changes in the expansion rate over the past several billion years(5-7). However, it is necessary to extend this expansion history still farther away (hence further back in time) in order to begin to distinguish the causes of the expansion-rate changes-such as the slowing caused by the gravitational attraction of the Universe's mass density, and the possibly counteracting effect of the cosmological constants. Here we report the most distant spectroscopically confirmed supernova, Spectra and photometry from the largest telescopes on the ground and in space show that this ancient supernova is strikingly similar to nearby, recent type Ia supernovae, When combined with previous measurements of nearer supernovae(2,5), these new measurements suggest that we may live in a low-mass-density universe. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Univ Padua, Dipartimento Astron, I-35122 Padua, Italy. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Paris 06, LPNHE, F-75252 Paris 05, France. Univ Paris 07, LPNHE, F-75252 Paris 05, France. Observ Strasbourg, F-67000 Strasbourg, France. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Stockholm, Dept Phys, S-11385 Stockholm, Sweden. European So Observ, D-85748 Garching, Germany. Coll France, F-75231 Paris, France. European So Observ, Santiago 19, Chile. ESA, Dept Space Sci, Div Astrophys, F-75738 Paris 15, France. Univ Barcelona, Fac Phys, Dept Astron, E-08028 Barcelona, Spain. Yale Univ, Dept Phys, New Haven, CT 06520 USA. Isaac Newton Grp, E-38780 Santa Cruz De La Palma, Canary Islands, Spain. RP Perlmutter, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,MS 50-232, Berkeley, CA 94720 USA. EM saul@lbl.gov RI Perlmutter, Saul/I-3505-2015 OI Perlmutter, Saul/0000-0002-4436-4661 NR 28 TC 1529 Z9 1540 U1 7 U2 25 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD JAN 1 PY 1998 VL 391 IS 6662 BP 51 EP 54 DI 10.1038/34124 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YP888 UT WOS:000071326100043 ER PT J AU Bromley, BC Miller, WA Pariev, VI AF Bromley, BC Miller, WA Pariev, VI TI The inner edge of the accretion disk around a supermassive black hole SO NATURE LA English DT Article ID MCG-6-30-15 AB Massive black holes are generally thought to exist at the centres of galaxies', but an unambiguous identification of a black hole has been impeded by a lack of evidence for the strong-field relativistic effects expected in the vicinity of such an object. Several years ago, a very broad iron emission line was discovered in the active galaxy MCG-6-30-15, indicative of emission from an accretion disk near the event horizon of a black hole, But this interpretation, based on the line profile, was somewhat model dependent (refs 2-5). Here we present an analysis of the iron-line emission from MCG-6-30-15 that is insensitive to the details (for example, disk thickness and emissivity) of the disk model used. We find that the inner edge of the disk material giving rise to the line is within 2.6 +/- 0.3 times the Schwarzschild radius-the event horizon of a non-rotating black hole-at the 95% confidence level. Changes to the disk parameters can only decrease the inner radius of the emitting region, and so we can be confident that we are observing emission from gravitationally bound material in the strong-field region of a supermassive black hole. Moreover, we find that the black hole is rotating at a rate which is greater than or similar to 23 +/- 17% of the theoretical maximum, although this conclusion is model dependent. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Calif Los Alamos Natl Lab, MS B288, Los Alamos, NM 87545 USA. PN Lebedev Phys Inst, Moscow 117924, Russia. RP Bromley, BC (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,MS-51, Cambridge, MA 02138 USA. NR 13 TC 42 Z9 42 U1 0 U2 1 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 1 PY 1998 VL 391 IS 6662 BP 54 EP 56 DI 10.1038/34130 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YP888 UT WOS:000071326100044 ER PT J AU Hughen, KA Overpeck, JT Lehman, SJ Kashgarian, M Southon, J Peterson, LC Alley, R Sigman, DM AF Hughen, KA Overpeck, JT Lehman, SJ Kashgarian, M Southon, J Peterson, LC Alley, R Sigman, DM TI Deglacial changes in ocean circulation from an extended radiocarbon calibration SO NATURE LA English DT Article ID NORTH-ATLANTIC; LAST DEGLACIATION; YOUNGER DRYAS; SNOW ACCUMULATION; CLIMATE-CHANGE; C-14; CORALS; GREENLAND; CHRONOLOGY; SEDIMENTS AB Temporal variations in the atmospheric concentration of radiocarbon sometimes result in radiocarbon-based age-estimates of biogenic material that do not agree with true calendar age, This problem is particularly severe beyond the limit of the high-resolution radiocarbon calibration based on tree-ring data, which stretches back only to(1,2) about 11.8 kyr before present (BP), near the termination of the Younger Dryas cold period If a wide range of palaeoclimate records are to be exploited for better understanding the rates and patterns of environmental change during the last deglaciation, extending the well-calibrated radiocarbon timescale back further in time is crucial. Several studies attempting such an extension, using uranium/thorium-dated corals(3-5) and laminae counts in varved sediments(6-9), show conflicting results, Here we use radiocarbon data from varved sediments in the Cariaco basin, in the southern Caribbean Sea, to construct an accurate and continuous radiocarbon calibration for the period 9 to 14.5 kyr sp, nearly 3,000 years beyond the tree-ring-based calibration, A simple model compared to the calculated atmospheric radiocarbon concentration and palaeoclimate data from the same sediment core suggests that North Atlantic Deep Water formation shut down during the Younger Dryas period, but was gradually replaced by an alternative mode of convection, possibly via the formation of North Atlantic Intermediate Water. C1 Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA. NOAA, Natl Geophys Data Ctr, Paleoclimatol Program, Boulder, CO 80303 USA. Univ Calif Lawrence Livermore Natl Lab, CAMS, Livermore, CA 94551 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. Penn State Univ, Ctr Earth Syst Sci, University Pk, PA 16802 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Univ Colorado, INSTAAR, Boulder, CO 80309 USA. RP Hughen, KA (reprint author), Harvard Univ, Dept Earth & Planetary Sci, 20 Oxford St, Cambridge, MA 02138 USA. RI Kashgarian, Michaele/E-1665-2011; Sigman, Daniel/A-2649-2008 OI Kashgarian, Michaele/0000-0001-7824-8418; Sigman, Daniel/0000-0002-7923-1973 NR 30 TC 259 Z9 266 U1 3 U2 31 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 1 PY 1998 VL 391 IS 6662 BP 65 EP 68 DI 10.1038/34150 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YP888 UT WOS:000071326100048 ER PT J AU Jap, BK Walian, PJ AF Jap, BK Walian, PJ TI Gliding through sugar channels: how sweet it is! SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID RESOLUTION; PORINS AB The recently determined structures of ScrY and LamB porin, with and without bound ligands, have provided atomic-level details about the transit pathway of sugars through these channels and in turn revealed a novel transport mechanism. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Jap, BK (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Donner Lab, Div Life Sci, Berkeley, CA 94720 USA. NR 9 TC 3 Z9 3 U1 0 U2 0 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD JAN PY 1998 VL 5 IS 1 BP 6 EP 8 DI 10.1038/nsb0198-6 PG 3 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA YQ141 UT WOS:000071352600003 PM 9437417 ER PT J AU Howse, JW Abdallah, CT Heileman, GL AF Howse, JW Abdallah, CT Heileman, GL TI A learning algorithm for applying synthesized stable dynamics to system identification SO NEURAL NETWORKS LA English DT Article DE stability; learning algorithm; system identification AB In this paper the models discussed by Cohen are extended by introducing an input term. This allows the resulting models to be utilized for system identification tasks. This approach gives a direct way to encode qualitative information such as attractor dimension into the model. We prove that this model is stable in the sense that a bounded input leads to a bounded state when a minor restriction is imposed on the Lyapunov function. By employing this stability result, we are able to find a learning algorithm which guarantees convergence to a set of parameters for which the error between the model trajectories and the desired trajectories vanishes. (C) 1998 Elsevier Science Ltd. All lights reserved. C1 Univ Calif Los Alamos Natl Lab, Computat Sci Methods Grp, Los Alamos, NM 87545 USA. Univ New Mexico, Dept Elect & Comp Engn, Albuquerque, NM 87131 USA. RP Howse, JW (reprint author), Univ Calif Los Alamos Natl Lab, Computat Sci Methods Grp, X-CM,POB 1663,Mail Stop F645, Los Alamos, NM 87545 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0893-6080 J9 NEURAL NETWORKS JI Neural Netw. PD JAN PY 1998 VL 11 IS 1 BP 81 EP 87 DI 10.1016/S0893-6080(97)00109-3 PG 7 WC Computer Science, Artificial Intelligence SC Computer Science GA YY236 UT WOS:000072126900006 ER PT J AU Smith, GS Schloesser, R Brodie, JD Dewey, SL Logan, J Vitkun, SA Simkowitz, P Hurley, A Cooper, T Volkow, ND Cancro, R AF Smith, GS Schloesser, R Brodie, JD Dewey, SL Logan, J Vitkun, SA Simkowitz, P Hurley, A Cooper, T Volkow, ND Cancro, R TI Glutamate modulation of dopamine measured in vivo with positron emission tomography (PET) and C-11-raclopride in normal human subjects SO NEUROPSYCHOPHARMACOLOGY LA English DT Article DE ketamine; glutamate; dopamine; C-11-raclopride; positron emission tomography ID VENTRAL TEGMENTAL AREA; AMINO-ACID RECEPTORS; C-11 RACLOPRIDE; STRIATAL DOPAMINE; HUMAN-BRAIN; NEUROENDOCRINE RESPONSES; RAT-BRAIN; BINDING; PHENCYCLIDINE; KETAMINE AB Subanesthetic doses of the noncompetitive N-methyl-D-aspartate (NMDA) antagonist ketamine exacerbate psychosis in schizophrenic patients, and ketamine has significant abuse liability. These observations indicate that a secondary effect of ketamine may be to increase dopamine concentrations. The present study was undertaken using positron emission tomography (PET) and the dopamine (D-2) radiotracer C-11-raclopride to determine whether ketamine would decrease D-2 receptor availability, indicative of an increase in dopamine concentrations. Two scans were performed in seven male control subjects before and after administration of ketamine (0.5 mg/kg, IV infused over 20 min). Ketamine significantly increased cortisol levels and decreased dopamine receptor availability in the striatum (specific binding), but not in the cerebellum (nonspecific binding). In addition, the cerebellar binding subtracted from the striatal binding (to account for changes in nonspecific binding) was significantly decreased after ketamine administration. These results provide in vivo evidence for the ability of ketamine to increase striatal dopamine concentrations, consistent with the role of the NMDA receptor in modulating dopamine function. (C) 1998 American College of Neuropsychopharmacology. Published by Elsevier Science Inc. C1 NYU,SCH MED,DEPT PSYCHIAT,GEN CLIN RES CTR,NEW YORK,NY. NYU,SCH MED,DEPT MED,GEN CLIN RES CTR,NEW YORK,NY. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. SUNY STONY BROOK,DEPT ANESTHESIOL,STONY BROOK,NY 11794. NATHAN S KLINE INST PSYCHIAT RES,ANALYT PSYCHOPHARMACOL LAB,ORANGEBURG,NY. RI Schlosser, Ralf/F-2822-2010 FU NIMH NIH HHS [MH47277, MH49936]; NINDS NIH HHS [NS15638] NR 50 TC 144 Z9 149 U1 0 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0893-133X J9 NEUROPSYCHOPHARMACOL JI Neuropsychopharmacology PD JAN PY 1998 VL 18 IS 1 BP 18 EP 25 PG 8 WC Neurosciences; Pharmacology & Pharmacy; Psychiatry SC Neurosciences & Neurology; Pharmacology & Pharmacy; Psychiatry GA YJ479 UT WOS:A1998YJ47900003 PM 9408915 ER PT J AU Busch, K Soukoulis, C AF Busch, K Soukoulis, C TI Effective-medium and coherent-potential approximation SO NEW ASPECTS OF ELECTROMAGNETIC AND ACOUSTIC WAVE DIFFUSION SE SPRINGER TRACTS IN MODERN PHYSICS LA English DT Review C1 Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. RP Busch, K (reprint author), Univ Toronto, Dept Phys, 60 St George St, Toronto, ON M5S 1A7, Canada. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN 33 PA HEIDELBERGER PLATZ 3, W-1000 BERLIN 33, GERMANY SN 0081-3869 J9 SPRINGER TR MOD PHYS PY 1998 VL 144 BP 45 EP 50 PG 6 WC Physics, Multidisciplinary SC Physics GA BL17S UT WOS:000074550100012 ER PT S AU Guzik, JA AF Guzik, JA BE Deubner, FL ChristensenDalsgaard, J Kurtz, D TI Delta Scuti stars: Theory SO NEW EYES TO SEE INSIDE THE SUN AND STARS: PUSHING THE LIMITS OF HELIO- AND ASTEROSEISMOLOGY WITH NEW OBSERVATIONS FROM THE GROUND AND FROM SPACE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 185th Symposium of the International-Astronomical-Union on New Eyes to See Inside the Sun and Stars CY AUG 18-22, 1997 CL KYOTO, JAPAN SP Int Astron Union ID STELLAR OSCILLATIONS; ROTATION; PULSATION; FREQUENCIES; MODEL C1 Los Alamos Natl Lab, XTA, Los Alamos, NM 87545 USA. RP Guzik, JA (reprint author), Los Alamos Natl Lab, XTA, MS B220, Los Alamos, NM 87545 USA. EM joy@lanl.gov NR 37 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-5075-8 J9 IAU SYMP PY 1998 IS 185 BP 331 EP 338 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM51L UT WOS:000078932400074 ER PT S AU Fontaine, G Charpinet, S Brassard, P Chayer, P Rogers, FJ Iglesias, CA Dorman, B AF Fontaine, G Charpinet, S Brassard, P Chayer, P Rogers, FJ Iglesias, CA Dorman, B BE Deubner, FL ChristensenDalsgaard, J Kurtz, D TI EC14026 stars: Theoretical considerations SO NEW EYES TO SEE INSIDE THE SUN AND STARS: PUSHING THE LIMITS OF HELIO- AND ASTEROSEISMOLOGY WITH NEW OBSERVATIONS FROM THE GROUND AND FROM SPACE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 185th Symposium of the International-Astronomical-Union on New Eyes to See Inside the Sun and Stars CY AUG 18-22, 1997 CL KYOTO, JAPAN SP Int Astron Union ID SUBDWARF B-STARS; HOT C1 Univ Montreal, Dept Phys, Montreal, PQ H3C 3J7, Canada. Univ Calif Berkeley, Ctr Euv Astrophys, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Fontaine, G (reprint author), Univ Montreal, Dept Phys, CP 6128, Montreal, PQ H3C 3J7, Canada. NR 12 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-5075-8 J9 IAU SYMP PY 1998 IS 185 BP 367 EP 374 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM51L UT WOS:000078932400079 ER PT S AU Roussel-Dupre, D Pfafman, T Bloch, J Theiler, J AF Roussel-Dupre, D Pfafman, T Bloch, J Theiler, J BE McLean, BJ Golombek, DA Hayes, JJE Payne, HE TI EUV sources and transients detected by the ALEXIS satellite SO NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 179th Symposium of the International-Astronomical-Union on New Horizons from Multi-Wavelength Sky Surveys CY AUG 26-30, 1996 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Int Astron Union HO JOHNS HOPKINS UNIV C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Roussel-Dupre, D (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4802-8 J9 IAU SYMP PY 1998 IS 179 BP 144 EP 146 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK53M UT WOS:000072466600031 ER PT S AU Newberg, HJ Yanny, B AF Newberg, HJ Yanny, B BE McLean, BJ Golombek, DA Hayes, JJE Payne, HE TI QSO color selection in the SDSS SO NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 179th Symposium of the International-Astronomical-Union on New Horizons from Multi-Wavelength Sky Surveys CY AUG 26-30, 1996 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Int Astron Union HO JOHNS HOPKINS UNIV C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Newberg, HJ (reprint author), Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4802-8 J9 IAU SYMP PY 1998 IS 179 BP 291 EP 292 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK53M UT WOS:000072466600067 ER PT S AU Moran, EC AF Moran, EC BE McLean, BJ Golombek, DA Hayes, JJE Payne, HE TI Exposing new components of the x-ray background with multi-wavelength sky surveys SO NEW HORIZONS FROM MULTI-WAVELENGTH SKY SURVEYS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 179th Symposium of the International-Astronomical-Union on New Horizons from Multi-Wavelength Sky Surveys CY AUG 26-30, 1996 CL JOHNS HOPKINS UNIV, BALTIMORE, MARYLAND SP Int Astron Union HO JOHNS HOPKINS UNIV ID EINSTEIN C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Moran, EC (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4802-8 J9 IAU SYMP PY 1998 IS 179 BP 358 EP 359 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK53M UT WOS:000072466600089 ER PT S AU Bloom, BR Iden, CR Mastrangelo, IA AF Bloom, BR Iden, CR Mastrangelo, IA BE Ens, W Standing, KG Chernushevich, IV TI Non-covalent hetero- and homo-oligomeric protein complexes reassociate differentially during MALDI-MS analysis SO NEW METHODS FOR THE STUDY OF BIOMOLECULAR COMPLEXES SE NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES C, MATHEMATICAL AND PHYSICAL SCIENCES LA English DT Proceedings Paper CT NATO Advanced Research Workshop on New Methods for the Study of Molecular Aggregates CY JUN 16-20, 1996 CL LODGE KANANASKIS VILLAGE, KANANASKIS, CANADA SP NATO, Univ Manitoba, Dept Phys HO LODGE KANANASKIS VILLAGE C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Bloom, BR (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0258-2023 BN 0-7923-5003-0 J9 NATO ADV SCI I C-MAT PY 1998 VL 510 BP 209 EP 216 PG 8 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Chemistry, Analytical; Chemistry, Physical SC Biochemistry & Molecular Biology; Biophysics; Chemistry GA BK69N UT WOS:000073108600017 ER PT S AU Murray, JR AF Murray, JR BE Auerbach, J Bliss, E Dixit, S Feit, M Gold, D Haan, S Henesian, M Jones, O Lawson, J London, R Manes, K Munro, D Murray, J Pollaine, S Renard, P Rothenberg, J Sacks, R Speck, R TI Overview of the National Ignition Facility SO NIF LASER SYSTEM PERFORMANCE RATINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd International Conference on Solid State Lasers for Application to Inertial Confinement Fusion CY JUN 07-12, 1998 CL MONTEREY, CA SP Lawrence Livermore Natl Lab, Commissariat Energie Atom ID INERTIAL CONFINEMENT FUSION; LASER C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Murray, JR (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-488, Livermore, CA 94551 USA. NR 5 TC 12 Z9 12 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2951-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3492 SI SUPPLEMENT BP 1 EP 10 PG 10 WC Optics; Physics, Fluids & Plasmas SC Optics; Physics GA BN61J UT WOS:000082355100001 ER EF