FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Geltmacher, AB Koss, DA Matic, P Stout, MG AF Geltmacher, AB Koss, DA Matic, P Stout, MG TI A modeling study of the effect of stress state on void linking during ductile fracture SO ACTA MATERIALIA LA English DT Article ID POROUS PLASTIC SOLIDS; SHEAR LOCALIZATION; NOTCHED BARS; GROWTH; NUCLEATION; FAILURE; DEFORMATION; COALESCENCE; RUPTURE AB The deformation and fracture behavior of sheer specimens containing either pairs of ''pseudo''-random arrays of equi-sized holes has been examined in both uniaxial and equal-biaxial tension utilizing experiment as well as computer simulation. Our results show for this plane-stress situation that hole linking is always caused by flow localization within the ligaments between neighboring holes. The imposed strains to initiate flow localization and subsequent ligament failure are sensitive to stress state (uniaxial versus biaxial) and the location of the neighboring hole(s). A significant observation is the influence of stress state on the multidirectionality of hole linking paths: specifically, increasing the biaxial component of the stress state increases the number of holes that can participate in a hole-linking process. A related implication is that the strain range over which void linking occurs decreases with increasing triaxiality of the stress state; in effect, after the initiation of void linking, its propagation is accelerated under biaxial or triaxial tension. C1 PENN STATE UNIV, DEPT MET SCI & ENGN, UNIVERSITY PK, PA 16802 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP USN, RES LAB, CODE 6382, WASHINGTON, DC 20375 USA. NR 30 TC 28 Z9 28 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD JUN PY 1996 VL 44 IS 6 BP 2201 EP 2210 DI 10.1016/1359-6454(95)00366-5 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA UM676 UT WOS:A1996UM67600002 ER PT J AU Menon, ESK Fox, AG AF Menon, ESK Fox, AG TI On the determination of the Debye-Waller factor and structure factors of NiAl by X-ray powder diffraction SO ACTA MATERIALIA LA English DT Article ID BONDING CHARGE-DENSITY; EXTINCTION; ALLOYS; DIFFRACTOMETRY AB A conventional powder X-ray diffraction experiment was performed on close-to stoichiometric beta-NiAl (B2 structure) using a Cu target. From the integrated intensity data the lattice parameters and room temperature Debye-Waller factors of beta-NiAl were determined. During the analysis of the integrated intensities, great care was taken to ensure proper treatment of extinction which was found to depend on the mosaic crystal size rather than the powder particle size. Other factors such as dispersion, thermal diffuse scattering and preferred orientation were found to have less of an effect on the integrated intensity analysis. As a result of this improved analytical procedure, Debye-Waller factors for beta-NiAl were determined which are in close agreement with the accurate values obtained by single crystal X-ray and electron diffraction. This is in contrast with previous powder X-ray diffraction work on beta-NiAl, where poor values of the Debye-Waller factor were usually obtained due to the failure to correct for extinction. The effects of bonding in the solid state were also examined and it was found that the use of accurate crystal structure factors for beta-NiAl in the analysis as opposed to those calculated from free atom scattering factors had no significant effect on the experimental Debye-Waller factor values. RP Menon, ESK (reprint author), USN,POSTGRAD SCH,DEPT MECH ENGN,MAT SCI SECT,MONTEREY,CA 93940, USA. NR 44 TC 6 Z9 6 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JUN PY 1996 VL 44 IS 6 BP 2547 EP 2555 DI 10.1016/1359-6454(95)00351-7 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA UM676 UT WOS:A1996UM67600035 ER PT J AU Chang, EJ Kailasanath, K AF Chang, EJ Kailasanath, K TI Simulations of particle dynamics in a confined shear flow SO AIAA JOURNAL LA English DT Article ID ACOUSTIC-VORTEX INTERACTIONS; NUMERICAL SIMULATIONS; ISOTROPIC TURBULENCE; DISPERSION; LAYER; JET AB The dynamic behavior of particles injected into the high-speed shear how in the confined geometry of an axisymmetric dump combustor is studied computationally using the flux-corrected transport algorithm and a Lagrangian approach to track particles in the how. Small particles are seen to travel with the large vortical structures, while intermediate sized particles are seen to form sheets as they are ejected from these structures. Dispersion of the particles is found to be optimal at Stokes numbers on the order of unity when particles that have been deposited on the combustor walls are neglected. Further analysis shows that it is the shedding frequency that governs the dispersion, even at downstream locations where the first merging frequency governs the fluid how, This property is observed for all particle sizes studied except for cases at very low Stokes numbers, where the merging frequency, as well as the frequency obtained by combining the merging and shedding frequencies, is observed. A correlation between particle size and flow vorticity is also obtained and shows that high concentrations of particles can he associated with high vorticity for small particles, whereas the opposite is true for intermediate to large sized particles. RP Chang, EJ (reprint author), USN,RES LAB,CTR REACT FLOW & DYNAM SYST,COMPUTAT PHYS & FLUID DYNAM LAB,WASHINGTON,DC 20375, USA. NR 25 TC 12 Z9 12 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD JUN PY 1996 VL 34 IS 6 BP 1160 EP 1166 DI 10.2514/3.13207 PG 7 WC Engineering, Aerospace SC Engineering GA UN638 UT WOS:A1996UN63800010 ER PT J AU Maixner, MR AF Maixner, MR TI Role of secondary vorticity in parallel blade-vortex interactions SO AIAA JOURNAL LA English DT Article ID EDGE INTERACTION; LEADING-EDGE; LAYERS AB This work incorporates viscous effects and the no-slip criterion in analyzing the blade-vortex interaction (BVI) problem with the discrete vortex model. Most previous BVI investigations have been purely potential in nature, so that only the zero normal velocity criterion was imposed on the body surface. In the current work, a boundary-layer code that predicts separation on an infinite flat plate under the influence of a line vortex is adapted to the BVI problem, so that it may be used with a semi-infinite plate in a flowfield composed of a freestream and numerous discrete vortices. Although a steady, laminar boundary-layer assumption is used to predict separation, the kinematics resulting from the interaction of the primary vortex and the shed vorticity are in agreement with previous observations. C1 USN,POSTGRAD SCH,MONTEREY,CA 93943. NR 49 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD JUN PY 1996 VL 34 IS 6 BP 1195 EP 1202 DI 10.2514/3.13212 PG 8 WC Engineering, Aerospace SC Engineering GA UN638 UT WOS:A1996UN63800015 ER PT J AU Love, RW AF Love, RW TI Sea soldiers in the Cold War: Amphibious warfare, 1945-1991 - Alexander,JH, Bartlett,ML SO AMERICAN HISTORICAL REVIEW LA English DT Book Review RP Love, RW (reprint author), USN ACAD,ANNAPOLIS,MD 21402, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER HISTORICAL REVIEW PI WASHINGTON PA 400 A ST SE, WASHINGTON, DC 20003 SN 0002-8762 J9 AM HIST REV JI Am. Hist. Rev. PD JUN PY 1996 VL 101 IS 3 BP 944 EP 945 DI 10.2307/2169616 PG 2 WC History SC History GA UT994 UT WOS:A1996UT99400202 ER PT J AU Corwin, AL Khiem, HB Clayson, ET Sac, PK Nhung, VTT Yen, VT Cuc, CTT Vaughn, D Merven, J Richie, TL Putri, MP He, JK Graham, R Wignall, FS Hyams, KC AF Corwin, AL Khiem, HB Clayson, ET Sac, PK Nhung, VTT Yen, VT Cuc, CTT Vaughn, D Merven, J Richie, TL Putri, MP He, JK Graham, R Wignall, FS Hyams, KC TI A waterborne outbreak of hepatitis E virus transmission in southwestern Vietnam SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Article ID EPIDEMIOLOGY AB A hepatitis outbreak affecting primarily adults occurred in southwestern Vietnam, along the Hau river bordering Cambodia, in June and July 1994. One month after the outbreak, sera and epidemiologic information were collected from 150 subjects: 50 patient cases, 50 matched, healthy community controls, and 50 geographic controls living 50 km upriver. The prevalence of immunoglobulin G (IgG) to hepatitis E virus (HEV) was significantly (P < 0.001) higher (76%) among cases than among the matched (38%), and geographic (38%) control populations. Immunoglobulin M to HEV was detected by enzyme-linked immunosorbent assay and Western blot in 16% of sera collected from patients one month after the outbreak. Hepatitis E virus RNA was detected with the polymerase chain reaction in 6% of sera from patients; RNA was not detected in either control group. These results indicate that HEV was the etiologic agent responsible for the outbreak. Children were under-represented among clinical cases. River water served as the principal source for drinking and bathing among most (96%) of the case and control study populations. Boiling of drinking water was negatively associated (P < 0.05) with IgG anti-HEV seropositivity. Unusually heavy rainfall likely contributed to conditions that favored the outbreak. This is the first recognized outbreak of epidemic HEV transmission in Indo-China. C1 USN, MED RES UNIT 2, JAKARTA 10400, INDONESIA. INST PASTEUR, HO CHI MINH CITY, VIETNAM. ARMED FORCES RES INST MED SCI, BANGKOK, THAILAND. USN, MED RES INST, BETHESDA, MD USA. NR 13 TC 59 Z9 62 U1 0 U2 7 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DR, STE 130, MCLEAN, VA 22101 USA SN 0002-9637 EI 1476-1645 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD JUN PY 1996 VL 54 IS 6 BP 559 EP 562 PG 4 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA UX379 UT WOS:A1996UX37900003 PM 8686771 ER PT J AU Hanafi, HA ElSawaf, BM Fryauff, DJ Modi, GB Presley, SM AF Hanafi, HA ElSawaf, BM Fryauff, DJ Modi, GB Presley, SM TI Experimental infection and transmission of Leishmania major by laboratory-reared Phlebotomus bergeroti parrot SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Article ID SAND FLIES; PSYCHODIDAE; PAPATASI; DIPTERA; SINAI; EGYPT AB The ability of colony-reared Phlebotomus bergeroti Parrot to successfully acquire and transmit Leishmania major (strain IPAP/EG 89/SI-177) was demonstrated in the laboratory. Female P. bergeroti were fed naturally on infected mice and artificially on infected blood suspension using a chick-skin membrane apparatus. Groups of sand flies, either infected on mice or by membrane feeding, were dissected and examined using fight microscopy at 2-6, 8, 10, and 11 days postfeeding. Heavy promastigote infection of the thoracic and abdominal midgut was observed in 10% (2 of 20) of the naturally infected flies. Promastigote: maturation was observed in 87% (81 of 93) of the artificially infected sand flies, with promastigotes observed in the cibarium and mouthparts at five days postinfecton, and infective metacyclic stage promastigotes observed at eight days postinfection. Ten days postinfection: 31% (10 of 32) of the remaining artificially infected sand flies refed on an uninfected BALB/c mouse. Twenty-eight days following exposure to the infective sand flies, leishmanial lesions were observed on the pads of the mouse's front feet. The development of lesions on mouse foot pads clearly suggests the potential of P. bergeroti to serve as a vector for L. major. C1 USN,MED RES UNIT 3,RES SCI DEPT,CAIRO,EGYPT. NR 19 TC 9 Z9 11 U1 0 U2 1 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DRIVE SUITE 130, MCLEAN, VA 22101 SN 0002-9637 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD JUN PY 1996 VL 54 IS 6 BP 644 EP 646 PG 3 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA UX379 UT WOS:A1996UX37900017 PM 8686785 ER PT J AU Klotz, FW Cohen, SJ Szarfman, A Aikawa, M Howard, RJ AF Klotz, FW Cohen, SJ Szarfman, A Aikawa, M Howard, RJ TI Cross-reactive epitope among proteins in Plasmodium falciparum Maurer's clefts and primate leukocytes and platelets SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Article ID INFECTED ERYTHROCYTES; THAI PATIENTS; LIVER STAGES; MALARIA; MEMBRANE; ANTIBODY; CELLS; AUTOANTIBODIES; MEROZOITE; VESICLES AB Erythrocytes infected with malaria parasites often contain membranous vesicles that are presumed to facilitate macromolecule traffic between the parasite and erythrocyte membranes. One such vesicle network, called Maurer's clefts, is expressed in Plasmodium falciparum-infected erythrocytes and contains a 50-kD polypeptide. Using a monoclonal antibody reactive with this polypeptide, we show that hepatic stages of P. falciparum express an epitope common to this blood-stage antigen. In addition, this epitope is cross-reactive with antigens expressed by primate leukocytes and platelets. Such epitopes may induce autoantibodies commonly seen in patients with malaria. C1 WALTER REED ARMY MED CTR, WALTER REED ARMY INST RES, DEPT IMMUNOL, WASHINGTON, DC 20307 USA. NIH, PARASIT DIS LAB, MALARIA SECT, BETHESDA, MD 20892 USA. GEORGE WASHINGTON UNIV, DEPT MICROBIOL & IMMUNOL, WASHINGTON, DC USA. USN, MED RES INST, BETHESDA, MD USA. UNIFORMED SERV UNIV HLTH SCI, BETHESDA, MD 20814 USA. CASE WESTERN RESERVE UNIV, INST PATHOL, CLEVELAND, OH 44106 USA. AFFYMAX RES INST, PALO ALTO, CA USA. FU NIAID NIH HHS [AI-10645] NR 31 TC 3 Z9 3 U1 0 U2 0 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DR, STE 130, MCLEAN, VA 22101 USA SN 0002-9637 EI 1476-1645 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD JUN PY 1996 VL 54 IS 6 BP 655 EP 659 PG 5 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA UX379 UT WOS:A1996UX37900020 PM 8686788 ER PT J AU Buckley, RG Conine, M AF Buckley, RG Conine, M TI Reliability of subjective fever in triage of adult patients SO ANNALS OF EMERGENCY MEDICINE LA English DT Article AB Study objective: To determine whether a historical complaint of fever is predictive of fever on emergency department triage. Methods: We prospectively questioned 651 ambulatory adult patients in a military tertiary care emergency department as to whether they had fever before oral temperature was taken. Fever was defined as a temperature of 38 degrees C (100.4 degrees F) or greater. Results: Sensitivity and specificity were 83% (95% confidence interval [CI], 71% to 95%) and 83% (95% CI, 80% to 86%), respectively. The prevalence of objective fever was 6.4%, yielding positive and negative predictive values of 25% (95% CI, 18% to 32%) and 99% (95% CI, 93% to 100%), respectively. Overall accuracy was 83% (95% CI, 80% to 86%). Conclusion: In this study, outpatients were fairly accurate in predicting fever. However in an outpatient population with a low overall prevalence of objective fever, the predictive value of a complaint of fever representing an objective fever remained low, Therefore the complaint of subjective fever should be interpreted with caution when it is used to support a given diagnosis in an ambulatory care setting. RP Buckley, RG (reprint author), USN,MED CTR,DEPT CLIN INVEST,SAN DIEGO,CA 92134, USA. NR 6 TC 2 Z9 2 U1 0 U2 1 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 SN 0196-0644 J9 ANN EMERG MED JI Ann. Emerg. Med. PD JUN PY 1996 VL 27 IS 6 BP 693 EP 695 DI 10.1016/S0196-0644(96)70185-3 PG 3 WC Emergency Medicine SC Emergency Medicine GA UP994 UT WOS:A1996UP99400002 PM 8644954 ER PT J AU Hester, JJ Scowen, PA Sankrit, R Lauer, TR Ajhar, EA Baum, WA Code, A Currie, DG Danielson, GE Ewald, SP Faber, SM Grillmair, CJ Groth, EJ Holtzman, JA Hunter, DA Kristian, J Light, RM Lynds, CR Monet, DG ONeil, EJ Shaya, EJ Seidelman, KP Westphal, JA AF Hester, JJ Scowen, PA Sankrit, R Lauer, TR Ajhar, EA Baum, WA Code, A Currie, DG Danielson, GE Ewald, SP Faber, SM Grillmair, CJ Groth, EJ Holtzman, JA Hunter, DA Kristian, J Light, RM Lynds, CR Monet, DG ONeil, EJ Shaya, EJ Seidelman, KP Westphal, JA TI Hubble space telescope WFPC2 imaging of M16: Photoevaporation and emerging young stellar objects SO ASTRONOMICAL JOURNAL LA English DT Article ID ORION-NEBULA; IONIZED-GAS; INTERSTELLAR CLOUDS; PHYSICAL CONDITIONS; MOLECULAR CLOUDS; NEARBY GALAXIES; SHOCK-WAVES; O-STARS; EMISSION; FRONTS AB We present Hubble Space Telescope WFPC2 images of elephant trunks in the H II region M16. There are three principle results of this study. First, the morphology and stratified ionization structure of the interface between the dense molecular material and the interior of the H II region is well understood in terms of photoionization of a photoevaporative flow. Photoionization models of an empirical density profile capture the essential features of the observations, including the extremely localized region of [S II] emission at the interface and the observed offset between emission peaks in lower and higher ionization lines. The details of this structure are found to be a sensitive function both of the density profile of the interface and of the shape of the ionizing continuum. Interpretation of the interaction of the photoevaporative flow with gas in the interior of the nebula supports the view that much of the emission from H II regions may arise in such flows. Photoionization of photoevaporative flows may provide a useful paradigm for interpreting a wide range of observations of H II regions. Second, we report the discovery of a population of small cometary globules that are being uncovered as the main bodies of the elephant trunks are dispersed. Several lines of evidence connect these globules to ongoing star formation, including the association of a number of globules with stellar objects seen in IR images of M16 or in the continuum HST images themselves. We refer to these structures as evaporating gaseous globules, or ''EGGs.'' These appear to be the same type of object as the nebular condensations seen previously in M42. The primary difference between the two cases is that in M16 we are seeing the objects from the side, while in M42 the objects are seen more nearly face-on against the backdrop of the ionized face of the molecular cloud. We find that the ''evaporating globule'' interpretation naturally accounts for the properties of objects in both nebulae, while avoiding serious difficulties with the competing ''evaporating disk'' model previously applied to the objects in M42. More generally, we find that disk-like structures are relatively rare in either nebula. Third, the data indicate that photoevaporation may have uncovered many EGGs while the stellar objects in them were still accreting mass, thereby freezing the mass distribution of the protostars at an early stage in their evolution. We conclude that the masses of stars in the cluster environment in M16 are generally determined not by the onset of stellar winds, as in more isolated regions of star formation, but rather by disruption of the star forming environment by the nearby O stars. (C) 1996 American Astronomical Society. C1 NATL OPT ASTRON OBSERV, KITT PEAK NATL OBSERV, TUCSON, AZ 85726 USA. UNIV WASHINGTON, DEPT ASTRON, SEATTLE, WA 98195 USA. UNIV WISCONSIN, WASHBURN OBSERV, DEPT ASTRON, MADISON, WI 53706 USA. UNIV MARYLAND, DEPT PHYS & ASTRON, COLLEGE PK, MD 20742 USA. CALTECH, DIV GEOL & PLANETARY SCI, PASADENA, CA 91125 USA. UNIV CALIF SANTA CRUZ, UNIV CALIF OBSERV, LICK OBSERV, BOARD STUDIES ASTRON & ASTROPHYS, SANTA CRUZ, CA 95064 USA. PRINCETON UNIV, DEPT PHYS, PRINCETON, NJ 08544 USA. LOWELL OBSERV, FLAGSTAFF, AZ 86001 USA. OBSERV CARNEGIE INST WASHINGTON, PASADENA, CA 91101 USA. CALTECH, IPAC, PASADENA, CA 91125 USA. USN OBSERV, FLAGSTAFF, AZ 86002 USA. USN OBSERV, WASHINGTON, DC 20392 USA. NEW MEXICO STATE UNIV, DEPT ASTRON, LAS CRUCES, NM 88003 USA. RP Hester, JJ (reprint author), ARIZONA STATE UNIV, DEPT PHYS & ASTRON, TEMPE, AZ 85287 USA. NR 51 TC 250 Z9 250 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUN PY 1996 VL 111 IS 6 BP 2349 EP + DI 10.1086/117968 PG 0 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UN631 UT WOS:A1996UN63100020 ER PT J AU Howell, SB DeYoung, JA Mattei, JA Foster, G Szkody, P Cannizzo, JK AF Howell, SB DeYoung, JA Mattei, JA Foster, G Szkody, P Cannizzo, JK TI Superoutburst photometry of AL Comae Berenices SO ASTRONOMICAL JOURNAL LA English DT Article ID SU-URSAE MAJORIS; DWARF NOVA; CATACLYSMIC VARIABLES; WZ-SGE; U-GEM; OUTBURST; SUPERHUMPS; LATITUDE; MODEL; STARS AB Photometric observations obtained during the 1995 April - May superoutburst of the dwarf nova AL Comae Berenices are presented. This star shows rare, large-amplitude outbursts, the last definitely seen in 1975. During the 1995 outburst, as with that of 1961, there was a sharp, two-magnitude temporary minimum in the outburst light curve at about 28 days after maximum light. We offer an explanation for such temporary minima involving the migration of a cooling wave within the accretion disk. V and I band CCD time-series photometry taken throughout the two-month-long event, reveal a complex period structure with two dominant periods, one near 82 min and one near 41 min. Early in the outburst, photometric modulations of 81 and 86 min were seen and are likely to be related to superorbital modulations seen in other large outburst amplitude dwarf novae. Superhumps developed after similar to 10 days and show a quasi-stable, nonphase coherent period of 82.5 min. A low-amplitude 41 min period was present throughout, also appearing not to be phase coherent. We conclude that the two dominant periods seen are of related origin and we list several possible mechanisms for their cause. Previous quiescence observations of AL Com have shown periods near 87 and 41 min. (C) 1996 American Astronomical Society. C1 USN OBSERV,WASHINGTON,DC 20392. AMER ASSOC VARIABLE STAR OBSERVERS,CAMBRIDGE,MA 02138. UNIV WASHINGTON,DEPT ASTRON,SEATTLE,WA 98195. NASA,GODDARD SPACE FLIGHT CTR,LHEA,GREENBELT,MD 20771. RP Howell, SB (reprint author), PLANETARY SCI INST,ASTROPHYS GRP,620 N 6TH AVE,TUCSON,AZ 85705, USA. NR 52 TC 39 Z9 39 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD JUN PY 1996 VL 111 IS 6 BP 2367 EP 2378 DI 10.1086/117970 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UN631 UT WOS:A1996UN63100022 ER PT J AU Chipman, SF AF Chipman, SF TI Still far too sexy a topic SO BEHAVIORAL AND BRAIN SCIENCES LA English DT Article ID MATHEMATICS; PERFORMANCE; PERSPECTIVE AB Geary is highly selective in his use of the literature on gender differences. His assumption of consistent female inferiority in mathematics is not necessarily supported by the facts. RP Chipman, SF (reprint author), OFF NAVAL RES,ARLINGTON,VA 22217, USA. NR 8 TC 2 Z9 2 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0140-525X J9 BEHAV BRAIN SCI JI Behav. Brain Sci. PD JUN PY 1996 VL 19 IS 2 BP 248 EP & PG 0 WC Psychology, Biological; Behavioral Sciences; Neurosciences SC Psychology; Behavioral Sciences; Neurosciences & Neurology GA VW467 UT WOS:A1996VW46700032 ER PT J AU McPhee, MG Ackley, SF Guest, P Huber, BA Martinson, DG Morison, JH Muench, RD Padman, L Stanton, TP AF McPhee, MG Ackley, SF Guest, P Huber, BA Martinson, DG Morison, JH Muench, RD Padman, L Stanton, TP TI The Antarctic Zone Flux Experiment SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID WINTER MIXED LAYER; SEA-ICE; WEDDELL SEA; PACK ICE; OCEAN; WATER; MODEL; TEMPERATURE; THICKNESS; POLYNYA AB In winter the eastern Weddell Sea in the Atlantic sector of the Southern Ocean hosts some of the most dynamic air-ice-sea interactions found on earth. Sea ice in the region is kept relatively thin by heat flux from below, maintained by upper-ocean stirring associated with the passage of intense, fast-moving cyclones. Ocean stratification is so weak that the possibility of deep convection exists, and indeed, satellite imagery from the Weddell Sea in the 1970s shows a large expanse of open water (the Weddell Polynya) that persisted through several seasons and may have significantly altered global deep-water production. Understanding what environmental conditions could again trigger widespread oceanic overturn may thus be an important key in determining the role of high latitudes in deep-ocean ventilation and global atmospheric warming. During the Antarctic Zone Flux Experiment in July and August 1994, response of the upper ocean and its ice cover to a series of storms was measured at two drifting stations supported by the National Science Foundation research icebreaker Nathaniel B. Palmer. This article describes the experiment, in which fluxes of heat, mass, and momentum were measured in the upper ocean, sea ice, and lower-atmospheric boundary layer. Initial results illustrate the importance of oceanic heat flux at the ice undersurface for determining the character of the sea ice cover. They also show how the heat flux depends both on high levels of turbulent mixing during intermittent storm events and on large variability in the stratified upper ocean below the mixed layer. C1 MCPHEE RES CO,NACHES,WA. USA,COLD REG RES & ENGN LAB,HANOVER,NH 03755. USN,POSTGRAD SCH,MONTEREY,CA. LAMONT DOHERTY EARTH OBSERV,PALISADES,NY 10964. WASHINGTON UNIV,POLAR SCI CTR,SEATTLE,WA. EARTH & SPACE RES,SEATTLE,WA. OREGON STATE UNIV,COLL OCEAN & ATMOSPHER SCI,CORVALLIS,OR 97331. NR 38 TC 60 Z9 61 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD JUN PY 1996 VL 77 IS 6 BP 1221 EP 1232 DI 10.1175/1520-0477(1996)077<1221:TAZFE>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VC043 UT WOS:A1996VC04300006 ER PT J AU Schwartz, IB Triandaf, I AF Schwartz, IB Triandaf, I TI Chaos and intermittent bursting in a reaction-diffusion process SO CHAOS LA English DT Article ID SYSTEMS; PATTERNS AB Karhunen-Loeve decomposition is done on a chaotic spatio-temporal solution obtained from a nonlinear reaction-diffusion model of a chemical system simulating a chemical process in an open Couette-flow reactor. Using a Galerkin projection of the dominant Karhunen-Loeve modes back onto the nonlinear partial differential system, we obtain an ordinary differential equation model of the same process. Major features such as intermittent and chaotic bursting of the nonlinear process as well as the mechanism of transition to chaos are shown to exist in the low-dimensional model as well as the PDE model. From the low-dimensional model the onset of intermittent bursts followed by small amplitude oscillations is shown to arise due to a sequence of saddle-node bifurcations. C1 SCI APPLICAT INT CORP,APPL PHYS OPERAT,MCLEAN,VA 22102. RP Schwartz, IB (reprint author), USN,RES LAB,SPECIAL PROJECT NONLINEAR SCI,DIV PLASMA PHYS,CODE 6700-3,WASHINGTON,DC 20375, USA. RI Schwartz, Ira/A-8073-2009 NR 22 TC 4 Z9 4 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1054-1500 J9 CHAOS JI Chaos PD JUN PY 1996 VL 6 IS 2 BP 229 EP 237 DI 10.1063/1.166168 PG 9 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA UT268 UT WOS:A1996UT26800013 ER PT J AU Foerster, JW AF Foerster, JW TI The edge effect in the northeast north Pacific Ocean SO CIENCIAS MARINAS LA English DT Article DE dual frequency sonar; plankton; frontal zone; North Pacific Current; Davidson Current; edge effect ID ZOOPLANKTON; PHYTOPLANKTON; ECOLOGY AB During April 1989, an intensive, short-term study of oceanic zooplankton tested the hypothesis that multidimensional distribution (patchiness, diffusion, layering) reflects the water mass interaction in the Northeast North Pacific Ocean (NENPO) during the spring season. The mixing water masses created an edge effect to which the biota responded. A dual frequency sonar array (38 kHz, 200 kHz), towing in tandem with an oceanographic sensor system, recorded zooplankton and environmental changes across various water masses. The tandem sensor system was a method to synoptically map the NENPO at the beginning of the productive period of early spring over an area of 3.3 x 10(5) km, 125 m in depth. Results from the plankton data showed patchiness and layers conforming to oceanographic physical features. These patterns appeared to define the interactions of the water masses and confirm the hypothesis. RP Foerster, JW (reprint author), USN ACAD,DEPT OCEANOG 9D,ANNAPOLIS,MD 21204, USA. NR 25 TC 0 Z9 0 U1 0 U2 0 PU INSTITUTO INVESTIGACIONES OCEANOLOGICAS, U A B C PI BAJA CALIFORNIA PA APARTADO POSTAL 423, ENSENADA, BAJA CALIFORNIA 22800, MEXICO SN 0185-3880 J9 CIENC MAR JI Ceinc. Mar. PD JUN PY 1996 VL 22 IS 2 BP 175 EP 190 PG 16 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA UN936 UT WOS:A1996UN93600003 ER PT J AU Lewis, T AF Lewis, T TI Tools for building wired SO COMPUTER LA English DT Editorial Material RP Lewis, T (reprint author), USN, POSTGRAD SCH, MONTEREY, CA 93940 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 90720-1314 USA SN 0018-9162 EI 1558-0814 J9 COMPUTER JI Computer PD JUN PY 1996 VL 29 IS 6 BP 12 EP 15 DI 10.1109/2.485889 PG 4 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA UP658 UT WOS:A1996UP65800010 ER PT J AU Rosenfeld, P BoothKewley, S Edwards, JE Thomas, MD AF Rosenfeld, P BoothKewley, S Edwards, JE Thomas, MD TI Responses on computer surveys: Impression management, social desirability, and the big brother syndrome SO COMPUTERS IN HUMAN BEHAVIOR LA English DT Article ID WORK AB The quality of responses on computer and paper surveys was examined using 247 Navy recruits randomly assigned to a 2 (anonymous/ identified) x 3 (administration modes: paper, computer-nonlinked, computer-linked) design. The computer-linked condition was included to simulate the 'Big Brother Syndrome' alluded to but not studied in past research. Higher levels of impression management were found in the identified computer-linked condition. It was concluded that perceiving that one's responses are linked to a larger database may lead to more impression management on computer surveys. Copyright (C) 1996 Elsevier Science Ltd C1 CALIF STATE UNIV SAN MARCOS,SAN MARCOS,CA 92096. RP Rosenfeld, P (reprint author), USN,CTR PERSONNEL RES & DEV,CODE 122,53335 RYNE RD,SAN DIEGO,CA 92152, USA. NR 31 TC 41 Z9 41 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0747-5632 J9 COMPUT HUM BEHAV JI Comput. Hum. Behav. PD SUM PY 1996 VL 12 IS 2 BP 263 EP 274 DI 10.1016/0747-5632(96)00006-4 PG 12 WC Psychology, Multidisciplinary; Psychology, Experimental SC Psychology GA UT466 UT WOS:A1996UT46600006 ER PT J AU Bui, TX AF Bui, TX TI Untitled SO DATA BASE FOR ADVANCES IN INFORMATION SYSTEMS LA English DT Editorial Material C1 USN, POSTGRAD SCH, DEPT SYST MANAGEMENT, MONTEREY, CA 93943 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 2 PENN PLAZA, STE 701, NEW YORK, NY 10121-0701 USA SN 0095-0033 J9 DATA BASE ADV INF SY JI Data Base Adv. Inf. Syst. PD SUM PY 1996 VL 27 IS 3 BP 11 EP 13 PG 3 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA WP310 UT WOS:A1996WP31000003 ER PT J AU Greason, KL Acosta, JA Magrino, TJ Choe, M AF Greason, KL Acosta, JA Magrino, TJ Choe, M TI Angiodysplasia as the cause of massive lower gastrointestinal hemorrhage in a young adult - Report of a case SO DISEASES OF THE COLON & RECTUM LA English DT Article DE angiodysplasia; vascular ectasia; arteriovenous malformation; lower gastrointestinal hemorrhage; colonic hemorrhage; 40 years of age or younger ID ARTERIOVENOUS-MALFORMATIONS; DIAGNOSIS; COLON AB PURPOSE: This study was undertaken to clarify the importance of bleeding vascular ectasia of the colon as the etiology of massive lower gastrointestinal hemorrhage in patients 40 years of age or younger. METHODS: An otherwise healthy 21-year-old male was admitted to a tertiary medical center with massive lower gastrointestinal hemorrhage. Technetium-labeled red blood cell scan, selective visceral angiography, and colonoscopy identified the source of bleeding as vascular abnormality of the descending colon. Segmental colonic resection was performed. RESULTS: Histologic review of the specimen demonstrated a vascular ectasia. The patient recovered uneventfully and has had no further stigmata of hemorrhage. A review of the literature was undertaken to make clear the significance of vascular ectasia as the source for massive colonic hemorrhage in the young adult. CONCLUSION: This is the first report that documents histologically a vascular ectasia as the source of massive lower gastrointestinal hemorrhage in an otherwise healthy patient less than 40 years of age. Vascular ectasia is an uncommon cause of lower gastrointestinal hemorrhage in the young adult. C1 USN,MED CTR,DEPT CLIN INVEST,SAN DIEGO,CA 92134. USN,MED CTR,DEPT GEN SURG,SAN DIEGO,CA 92134. USN,MED CTR,DEPT LAB,SAN DIEGO,CA 92134. NR 12 TC 8 Z9 8 U1 0 U2 0 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0012-3706 J9 DIS COLON RECTUM JI Dis. Colon Rectum PD JUN PY 1996 VL 39 IS 6 BP 702 EP 704 DI 10.1007/BF02056955 PG 3 WC Gastroenterology & Hepatology; Surgery SC Gastroenterology & Hepatology; Surgery GA UQ810 UT WOS:A1996UQ81000023 PM 8646962 ER PT J AU Marshall, L Heller, LM AF Marshall, L Heller, LM TI Reliability of transient-evoked otoacoustic emissions SO EAR AND HEARING LA English DT Article ID NORMALLY HEARING HUMANS; TEST-RETEST RELIABILITY; DISTORTION-PRODUCT; ACOUSTIC EMISSIONS; EARS; REPEATABILITY; FREQUENCY AB Objective: This investigation addressed four factors affecting transient-evoked otoacoustic emission (TEOAE) reliability: 1) The effect of evoking-stimulus level, 2) the effect of analyzing bandwidth, 3) the effect of slight-mild hearing loss, and 4) the effect of variability in the stimulus spectrum. Design: TEOAEs at 80, 74, 68, and 62 dB pSPL evoking-stimulus levels were measured in 25 ears spanning a range of hearing levels from normal to mild hearing loss for a minimum of 10 test sessions. Reliability was assessed for 1/6-, 1/3- 1/2-, and 1-octave analyzing bandwidths. Results: Evoking-stimulus level, hearing loss, and center frequency did not significantly affect reliability. With decreasing analyzing bandwidth, reliability decreased. Intrasubject test-retest standard deviations were 1.2 dB for a broadband analyzing bandwidth and 1.4, 1.5, 1.6, and 1.8 dB for 1-, 1/2-, 1/3-, and 1/6-octave analyzing bandwidths, respectively. Stimulus variability within narrower bandwidths was of sufficient magnitude to influence test-retest reliability, and attempts to correct for the variations in stimulus spectrum were unsuccessful. Slopes of the input-output functions differed across frequencies, with shallower slopes at higher frequencies, Conclusions: In general, TEOAE, amplitude is highly reliable. For those individuals in this study who were more variable, the variability was at low frequencies or across the entire frequency spectrum. For clinical applications, the choice of analyzing bandwidth should be based on consideration of both frequency specificity (where narrow analyzing bandwidths are optimal) and reliability (where wide analyzing bandwidths are optimal). RP Marshall, L (reprint author), USN,SUBMARINE MED RES LAB,BOX 900,SUBASE NLON,GROTON,CT 06349, USA. NR 38 TC 26 Z9 26 U1 1 U2 2 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0196-0202 J9 EAR HEARING JI Ear Hear. PD JUN PY 1996 VL 17 IS 3 BP 237 EP 254 DI 10.1097/00003446-199606000-00007 PG 18 WC Audiology & Speech-Language Pathology; Otorhinolaryngology SC Audiology & Speech-Language Pathology; Otorhinolaryngology GA UU554 UT WOS:A1996UU55400007 PM 8807266 ER PT J AU Luo, NP Baboo, KS Mwenya, D Diab, A Perera, CU Cummings, C Dupont, HL Murphy, JR Zumla, A AF Luo, NP Baboo, KS Mwenya, D Diab, A Perera, CU Cummings, C Dupont, HL Murphy, JR Zumla, A TI Isolation of Campylobacter species from Zambian patients with acute diarrhoea SO EAST AFRICAN MEDICAL JOURNAL LA English DT Article ID JEJUNI INFECTIONS; EPIDEMIOLOGY; CHILDREN AB Four hundred and one consecutive diarrhoea patients and 101 adult patients without diarrhoea were enrolled for this study from a health centre in Lusaka. Campylobacter was isolated from 6% of patients with acute diarrhoea. However, non of these were seen in control group. Further studies are being carried out to determine the importance of Campylobacter species with other bacterial pathogens, It will also be interesting to see its impact and association with human immunno deficiency virus in this region. C1 UNIV TEACHING HOSP,DEPT COMMUNITY MED,LUSAKA,ZAMBIA. USN,MED RES UNIT 3,DIARRHOEAL DIS & ENETER PATHOGENS PROGRAM,CAIRO,EGYPT. UNIV TEXAS,HLTH SCI CTR,SCH MED,CTR INFECT DIS,HOUSTON,TX. UNIV TEXAS,HLTH SCI CTR,SCH PUBL HLTH,HOUSTON,TX. OI Zumla, Alimuddin/0000-0002-5111-5735 NR 14 TC 3 Z9 3 U1 0 U2 0 PU EAST AFRICAN MEDICAL JOURNAL PI NAIROBI PA CHYULU ROAD PO BOX 41632, NAIROBI, KENYA SN 0012-835X J9 E AFR MED J JI East Afr. Med. J. PD JUN PY 1996 VL 73 IS 6 BP 395 EP 396 PG 2 WC Medicine, General & Internal SC General & Internal Medicine GA VV587 UT WOS:A1996VV58700013 PM 8840601 ER PT J AU SanchezMisiego, A Carra, RGM Zirino, A AF SanchezMisiego, A Carra, RGM Zirino, A TI Variability of the slopes of standard addition plots in the analysis of copper in seawater by anodic stripping voltammetry SO ELECTROANALYSIS LA English DT Article DE copper; speciation; stripping voltammetry; seawater ID SEA-WATER; COMPLEXATION; ELECTRODE; MERCURY; ETHYLENEDIAMINE; PACIFIC AB Copper in seawater was analyzed with a 'hybrid' mercury film-glassy carbon electrode using linear sweep, square wave and differential pulse anodic stripping voltammetry. The analyses were made in HCl (pH 2) and ethylenediamine (EN)-spiked seawater (9 < pH < 10), with and without purging the sample of dissolved oxygen. The relative slopes of the standard addition plots were used to determine the effect of mode and media alteration on the results. Square-wave voltammetry in EN-altered seawater, without oxygen purging, was found to be not only the most practical technique, but also highly sensitive. The 'chemistry' of the oxidation reaction during the stripping step was found to affect the experimental results markedly. For this reason, the peak current is an experimentally dependent measure of the ion flux, both, into and out of the electrode. C1 USN,COMMAND CONTROL & OCEAN SURVEILLANCE CTR,RDT & E DIV,SAN DIEGO,CA 92152. UNIV EXTREMADURA,DEPT QUIM ANALIT & ELECTROQUIM,BADAJOZ,SPAIN. UABC,INST INVEST OCEANOL,ENSENADA,BAJA CALIFORNIA,MEXICO. NR 13 TC 5 Z9 5 U1 0 U2 5 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 1040-0397 J9 ELECTROANAL JI Electroanalysis PD JUN PY 1996 VL 8 IS 6 BP 534 EP 538 DI 10.1002/elan.1140080607 PG 5 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA UW692 UT WOS:A1996UW69200006 ER PT J AU Sirkis, JS Kersey, AD Berkoff, TA Friebele, EJ AF Sirkis, JS Kersey, AD Berkoff, TA Friebele, EJ TI Extended range pseudo-heterodyne demodulation for fiber optic sensors SO EXPERIMENTAL MECHANICS LA English DT Article ID SCHEME AB This article describes a pseudo-heterodyne demodulation technique for interferometric fiber optic sensors that has a larger measurement range than is currently possible with pseudo-heterodyne demodulation. This sensor demodulation technique has a bandwidth of 30 Hz to 2.5 kHz, is capable of resolving optical phase angles as small as 5 x 10(-4) rad, and has a maximum measurement range of tens of radians in a bandwidth of 30-500 Hz. A comparison between the response obtained from a resistance strain gage and a fiber optic sensor using this demodulation is favorable. C1 USN,RES LAB,DIV OPT SCI,WASHINGTON,DC 20073. SFA INC,LANDOVER,MD 20785. RP Sirkis, JS (reprint author), UNIV MARYLAND,DEPT MECH ENGN,COLLEGE PK,MD 20742, USA. NR 13 TC 1 Z9 1 U1 0 U2 1 PU SOC EXPERIMENTAL MECHANICS PI BETHEL PA 7 SCHOOL STREET, BETHEL, CT 06801 SN 0014-4851 J9 EXP MECH JI Exp. Mech. PD JUN PY 1996 VL 36 IS 2 BP 135 EP 141 DI 10.1007/BF02328709 PG 7 WC Materials Science, Multidisciplinary; Mechanics; Materials Science, Characterization & Testing SC Materials Science; Mechanics GA UV653 UT WOS:A1996UV65300008 ER PT J AU Bandyopadhyay, PR GadelHak, M AF Bandyopadhyay, PR GadelHak, M TI Rotating gas-liquid flows in finite cylinders: Sensitivity of standing vortices to end effects SO EXPERIMENTS IN FLUIDS LA English DT Article AB The spiraling and straight gas-filled vortices formed by a rotating mixture of a gas and a liquid flowing through a finite-length cylinder are the subject of this paper. The working fluids considered are primarily helium and water. The bubbly liquid enters and leaves the cyclone-type separator tangentially. A gas-core vortex forms due to the resulting swirling motion of the mixture and, ideally, most of the gas leaves through an opening centered in the inlet end-wall of the vertical cylinder. The sensitivity of the gas-core configurations to the relative angle between the tangential inlet and outlet (phi) and to the length-to-diameter ratio of the cylinder (L/D) are investigated experimentally. Direct observations of the flow field are made using video and still cameras. The various gas-core vortex configurations are classified in a stability diagram. Although, as many as eight different types of core patterns have been identified, they are of two basic modes: straight and helical-spiral, or combinations of these. However, the straight mode is neither perfectly straight nor axisymmetric; it contains some non-uniformities. In an L/D-versus-phi plane, a linear ridge exists that is a sensitive stability line dividing the regimes of the straight and helical-spiral modes. The relationship between the two modes is examined, and the statistics of the wavelength and diameter of the helical spiral are given. A kinematic model is deducted and is used to explain the observed changes in the geometric parameters of the gas core. C1 UNIV NOTRE DAME,DEPT AEROSP & MECH ENGN,NOTRE DAME,IN 46556. RP Bandyopadhyay, PR (reprint author), USN,UNDERSEA WARFARE CTR,WEAP TECHNOL & UNDERSEA SYST DEPT,NEWPORT,RI 02841, USA. OI Gad-el-Hak, Mohamed/0000-0001-6279-5118 NR 14 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0723-4864 J9 EXP FLUIDS JI Exp. Fluids PD JUN PY 1996 VL 21 IS 2 BP 124 EP 138 PG 15 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA UT672 UT WOS:A1996UT67200008 ER PT J AU Duncan, MR Kiser, WR AF Duncan, MR Kiser, WR TI Acupuncture and migraine SO HEADACHE LA English DT Letter RP Duncan, MR (reprint author), USN HOSP,DEPT FAMILY PRACTICE,2080 CHILD ST,JACKSONVILLE,FL 32214, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC STUDY HEADACHE PI WOODBURY PA 875 KINGS HIGHWAY, STE 200, WOODBURY, NJ 08096 SN 0017-8748 J9 HEADACHE JI Headache PD JUN PY 1996 VL 36 IS 6 BP 397 EP 397 DI 10.1046/j.1526-4610.1996.3606397.x PG 1 WC Clinical Neurology SC Neurosciences & Neurology GA UV191 UT WOS:A1996UV19100012 PM 8707561 ER PT J AU Salas, E CannonBowers, JA AF Salas, E CannonBowers, JA TI Special section: Decision making in complex environments - Preface SO HUMAN FACTORS LA English DT Editorial Material RP Salas, E (reprint author), USN,CTR AIR WARFARE,TRAINING SYST DIV,WASHINGTON,DC, USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU HUMAN FACTORS SOC PI SANTA MONICA PA BOX 1369, SANTA MONICA, CA 90406 SN 0018-7208 J9 HUM FACTORS JI Hum. Factors PD JUN PY 1996 VL 38 IS 2 BP 191 EP 192 DI 10.1518/001872096779048075 PG 2 WC Behavioral Sciences; Engineering, Industrial; Ergonomics; Psychology, Applied; Psychology SC Behavioral Sciences; Engineering; Psychology GA UZ128 UT WOS:A1996UZ12800001 ER PT J AU CannonBowers, JA Salas, E Pruitt, JS AF CannonBowers, JA Salas, E Pruitt, JS TI Establishing the boundaries of a paradigm for decision-making research SO HUMAN FACTORS LA English DT Article AB In recent years a paradigm shift in decision-making research has occurred. Modern decision researchers are more interested in studying decision making as it occurs in the so-called real world under naturalistic conditions. As such, the naturalistic decision-making (NDM) movement has seen growing support in recent years. Our contention is that in order for a new paradigm of NDM to flourish, it is essential to define carefully and completely the nature of decisions that are of interest to investigate. Once this is done, it is then possible to determine the psychological processes and strategies that decision makers use to cope with this subset of naturalistic decisions and to establish acceptable methods of study. Given this need, the purpose of this article is to examine the concept of NDM as it has been treated in past work and to refine and expand this conceptualization. RP CannonBowers, JA (reprint author), USN,AIR WARFARE CTR,TRAINING TECHNOL DEV BRANCH,CTR TRAINING SYST DIV,12350 RES PKWY,ORLANDO,FL 32826, USA. OI Cannon-Bowers, Janis/0000-0003-2154-4456 NR 19 TC 46 Z9 46 U1 1 U2 9 PU HUMAN FACTORS SOC PI SANTA MONICA PA BOX 1369, SANTA MONICA, CA 90406 SN 0018-7208 J9 HUM FACTORS JI Hum. Factors PD JUN PY 1996 VL 38 IS 2 BP 193 EP 205 DI 10.1518/001872096779048066 PG 13 WC Behavioral Sciences; Engineering, Industrial; Ergonomics; Psychology, Applied; Psychology SC Behavioral Sciences; Engineering; Psychology GA UZ128 UT WOS:A1996UZ12800002 ER PT J AU Murray, SA Caldwell, BS AF Murray, SA Caldwell, BS TI Human performance and control of multiple systems SO HUMAN FACTORS LA English DT Article AB Many systems involving multiple remote sensors or machines require a single operator to control more than one device simultaneously. Interface design issues for such systems can be formidable because the inherent complexity of multiple-platform control creates significant opportunities for operator confusion and overload. An exploratory study was conducted to examine some of these issues using a simulated industrial security task. The experiment manipulated the type of remote sensor (fixed-site or mobile), the number of displays that had to be monitored, and two types of event complexity (number of targets and redundancy of target images) using response time as the dependent measure. Results showed that significant performance penalties may be encountered in multiple-platform control and that these penalties accumulate at seemingly low levels of complexity. C1 UNIV WISCONSIN,MADISON,WI. RP Murray, SA (reprint author), USN,CONTROL & OCEAN SURVEILLANCE CTR,RDT&E DIV,CODE 372,53406 WOODWARD RD,SAN DIEGO,CA 92152, USA. NR 11 TC 5 Z9 6 U1 0 U2 0 PU HUMAN FACTORS SOC PI SANTA MONICA PA BOX 1369, SANTA MONICA, CA 90406 SN 0018-7208 J9 HUM FACTORS JI Hum. Factors PD JUN PY 1996 VL 38 IS 2 BP 323 EP 329 DI 10.1518/001872096779048011 PG 7 WC Behavioral Sciences; Engineering, Industrial; Ergonomics; Psychology, Applied; Psychology SC Behavioral Sciences; Engineering; Psychology GA UZ128 UT WOS:A1996UZ12800012 PM 8768491 ER PT J AU Vieira, AJC Herczfeld, PR Contarino, VM Mizell, G AF Vieira, AJC Herczfeld, PR Contarino, VM Mizell, G TI Bulk Fabry-Perot intensity modulator for LIDAR systems SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article AB This letter reports on a bulk Fabry-Perot modulator operating at high optical intensities In the blue-green optical region, The design, fabrication, and characterization of a prototype modulator using LiNbO3 as the host material with mirrors deposited directly on the end facets of the crystal are described. A measured modulation depth of 23.9% was achieved. C1 USN,AIR WARFARE CTR,WARMINSTER,PA 18974. VIRGO OPT,PORT RICHEY,FL 34668. RP Vieira, AJC (reprint author), DREXEL UNIV,CTR MICROWAVE & LIGHTWAVE ENGN,PHILADELPHIA,PA 19104, USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD JUN PY 1996 VL 8 IS 6 BP 782 EP 784 DI 10.1109/68.502093 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA UM665 UT WOS:A1996UM66500016 ER PT J AU Li, PC Humblet, PA AF Li, PC Humblet, PA TI Zero-forcing electrical filters for direct detection optical systems SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article ID FABRY-PEROT INTERFEROMETERS; FINESSE; NETWORKS AB Intersymbol interference (ISI) in direct detection optical systems can limit channel spacing in frequency division multiplexing systems, and data rates, and transmission distances in long-haul transmission, It is desirable to reduce or cancel ISI in these situations, We investigate zero-forcing electrical filters to cancel ISI, and obtain tight performance hounds for minimum noise variance zero-forcing filters. We apply the results to Mach-Zehnder and Fabry-Perot filters, and to fibers with second order dispersion. We compare the performance of zero-forcing filters tea that of rectangular impulse response filters and find that zero-forcing filters are advantageous in severe ISI situations with multilevel signaling. C1 EURECOM,F-06904 SOPHIA ANTIPOLIS,FRANCE. RP Li, PC (reprint author), USN,CTR UNDERSEA WARFARE,NEWPORT,RI 02841, USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0090-6778 J9 IEEE T COMMUN JI IEEE Trans. Commun. PD JUN PY 1996 VL 44 IS 6 BP 707 EP 715 DI 10.1109/26.506387 PG 9 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA UQ224 UT WOS:A1996UQ22400012 ER PT J AU McMorrow, D Weatherford, TR Knudson, AR Buchner, S Melinger, JS Tran, LH Campbell, AB Marshall, PW Dale, CJ Peczalski, A Baier, S AF McMorrow, D Weatherford, TR Knudson, AR Buchner, S Melinger, JS Tran, LH Campbell, AB Marshall, PW Dale, CJ Peczalski, A Baier, S TI Charge-collection characteristics of GaAs heterostructure FETs fabricated with a low-temperature grown GaAs buffer layer SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 3rd European Symposium on Radiation and Its Effects on Components and Systems (RADECS 95) CY SEP 18-22, 1995 CL ARCACHON, FRANCE SP CNES, RADECS Assoc, IEEE, Nucl & Plasma Sci Soc ID MOLECULAR-BEAM EPITAXY; MESFETS; UPSETS AB The charge-collection characteristics of GaAs heterojunction-insulated-gate FETs fabricated with a low-temperature grown GaAs (LT GaAs) buffer layer are investigated as a function of device bias conditions for laser and ion irradiation. In accordance with earlier measurements, the LT GaAs FETs of this study exhibit a significant reduction in charge-collection efficiencies when compared to those of conventional FETs. This reduction in collected charge is associated with the efficient reduction of charge-enhancement mechanisms in the LT GaAs devices. It is revealed that charge-enhancement mechanisms processes do occur in the LT devices under certain bias conditions, although at significantly reduced levels when compared to conventional FETs. RP McMorrow, D (reprint author), USN, RES LAB, WASHINGTON, DC 20375 USA. NR 27 TC 11 Z9 11 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1996 VL 43 IS 3 BP 918 EP 923 DI 10.1109/23.510734 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA UT042 UT WOS:A1996UT04200024 ER PT J AU Buchner, S Campbell, AB McMorrow, D Melinger, J Masti, M Chen, YJ AF Buchner, S Campbell, AB McMorrow, D Melinger, J Masti, M Chen, YJ TI Modification of single event upset cross section of an SRAM at high frequencies SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 3rd European Symposium on Radiation and Its Effects on Components and Systems (RADECS 95) CY SEP 18-22, 1995 CL ARCACHON, FRANCE SP CNES, RADECS Assoc, IEEE, Nucl & Plasma Sci Soc AB Single event upset cross sections exhibit a clock frequency dependence, the origins of which have been investigated in a CMOS SRAM, both with a pulsed laser synchronized to the operation of the circuit and with a circuit simulator modeling program. C1 USN,RES LAB,WASHINGTON,DC 20375. UNIV MARYLAND,BALTIMORE,MD 21227. NR 5 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1996 VL 43 IS 3 BP 924 EP 930 DI 10.1109/23.510735 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA UT042 UT WOS:A1996UT04200025 ER PT J AU Mouret, I Calvet, MC Calvel, P Tastet, P Allenspach, M LaBel, KA Titus, JL Wheatley, CF Schrimpf, RD Galloway, KF AF Mouret, I Calvet, MC Calvel, P Tastet, P Allenspach, M LaBel, KA Titus, JL Wheatley, CF Schrimpf, RD Galloway, KF TI Experimental evidence of the temperature and angular dependence in SEGR SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 3rd European Symposium on Radiation and Its Effects on Components and Systems (RADECS 95) CY SEP 18-22, 1995 CL ARCACHON, FRANCE SP CNES, RADECS Assoc, IEEE, Nucl & Plasma Sci Soc ID POWER MOSFETS AB The temperature and angular dependence of Single-Event Gate Rupture (SEGR) experiments show that a normal incident favors SEGR and elevated temperature is insignificant. Both the oxide and substrate response play a major role in determining the SEGR sensitivity. C1 AEROSPATIALE,LES MUREAUX,FRANCE. UNIV ARIZONA,TUCSON,AZ 85721. ALCATEL ESPACE,TOULOUSE,FRANCE. CTR NATL ETUD SPATIALES,F-31055 TOULOUSE,FRANCE. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. USN,CTR SURFACE WARFARE,CRANE,IN 47522. RR2,DRUMS,PA 18222. RP Mouret, I (reprint author), MOTOROLA SEMICOND,TOULOUSE,FRANCE. RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 11 TC 5 Z9 6 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1996 VL 43 IS 3 BP 936 EP 943 DI 10.1109/23.510737 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA UT042 UT WOS:A1996UT04200027 ER PT J AU Dale, CJ Marshall, PW Fritz, ME delaChapelle, M Carts, MA LaBel, KA AF Dale, CJ Marshall, PW Fritz, ME delaChapelle, M Carts, MA LaBel, KA TI System level radiation response of a high performance fiber optic data bus SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 3rd European Symposium on Radiation and Its Effects on Components and Systems (RADECS 95) CY SEP 18-22, 1995 CL ARCACHON, FRANCE SP CNES, RADECS Assoc, IEEE, Nucl & Plasma Sci Soc AB We present experimental determinations of the total ionizing dose response and the proton-induced Single Event Upset (SEU) sensitivity of components comprising a 200 Mbps star coupled fiber optic data bus. These results are compared with the in-situ response of the operating system under proton bombardment, resulting in excellent correlation of the system error rate with proton-induced bit errors in the receiver photodiode. Modeling and error rate predictions for orbital performance indicate robust tolerance to even harsh natural space environments. C1 SFA INC,LANDOVER,MD 20785. BOEING CORP,SEATTLE,WA. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP Dale, CJ (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 14 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1996 VL 43 IS 3 BP 1030 EP 1037 DI 10.1109/23.510751 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA UT042 UT WOS:A1996UT04200041 ER PT J AU King, SE Dietrich, HB Henry, RL Katzer, DS Moore, WJ Phillips, GW Mania, RC AF King, SE Dietrich, HB Henry, RL Katzer, DS Moore, WJ Phillips, GW Mania, RC TI Development and characterization of zone melt growth GaAs for gamma-ray detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1995 Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY OCT 21-28, 1995 CL SAN FRANCISCO, CA AB GaAs is a potentially attractive material for room temperature x-ray and gamma-ray spectrometers. To date, the only high resolution GaAs devices were produced by epitaxial growth. The usefulness of detectors made from bulk grown semi-insulating (SI) GaAs has been limited by low charge collection efficiency caused, it is believed, by the high density of EL2 deep donor defects. Vertical zone melt (VZM) growth of GaAs has recently been developed at the Naval Research Laboratory. Zone refining and zone leveling techniques were used with VZM to reduce the level of impurities and the EL2 defects in bulk SI-GaAs. Schottky barrier and PIN diodes have been fabricated from the newly grown material. These devices were characterized using cl particles and gamma-rays. In this paper, the measurements and analysis of the first VZM GaAs devices are presented and compared with commercially available GaAs. The intent is to test the hypothesis that high purity, low defect GaAs material growth could lead to improved radiation detectors. C1 KENTUCKY STATE UNIV,FRANKFORT,KY 40601. RP King, SE (reprint author), USN,RES LAB,4555 OVERLOOK AVE SW,WASHINGTON,DC 20375, USA. RI Katzer, D. Scott/N-7841-2013 NR 8 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1996 VL 43 IS 3 BP 1376 EP 1380 DI 10.1109/23.507069 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA UT044 UT WOS:A1996UT04400057 ER PT J AU McGregor, DS Antolak, AJ Chui, HC Cross, ES Fang, ZQ Flatley, JE Goorsky, MS Henry, RL James, RB Look, DC Mier, MG Morse, DH Nordquist, PER Olsen, RW Pocha, M Schieber, M Schlesinger, TE Soria, E Toney, JE VanScyoc, J Yoon, H Wang, CL AF McGregor, DS Antolak, AJ Chui, HC Cross, ES Fang, ZQ Flatley, JE Goorsky, MS Henry, RL James, RB Look, DC Mier, MG Morse, DH Nordquist, PER Olsen, RW Pocha, M Schieber, M Schlesinger, TE Soria, E Toney, JE VanScyoc, J Yoon, H Wang, CL TI The investigation of custom grown vertical zone melt semi-insulating bulk gallium arsenide as a radiation spectrometer SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1995 Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY OCT 21-28, 1995 CL SAN FRANCISCO, CA ID LIQUID-ENCAPSULATED CZOCHRALSKI; GAAS; COMPENSATION AB Vertical zone melt (VZM) bulk GaAs boules have been zone refined (ZR) and zone leveled (ZL) to reduce EL2 deep donor levels and impurity concentrations with the intent of improving properties for gamma ray detectors. ZR and ZL GaAs boules had background impurity levels and deep donor EL2 concentrations near or below detectable limits. The crystal mosaic of the material at locations near the seed end was slightly superior to commercial liquid encapsulated Czochralski (LEC) material, and nearly equivalent to commercial vertical gradient freeze (VGF) material. The crystal mosaic in ZL material degraded towards the tail end. The homogeneity of the electrical properties for the ZL and ZR VZM material was inferior compared to commercially available bulk GaAs material. Post growth annealing may help to homogenize some electrical properties of the material. The charge collection efficiency of the ZR GaAs detectors was only 30% maximum, and only 25% maximum for the ZL GaAs detectors. Resulting gamma ray spectra was poor from detectors fabricated with the ZL or ZR VZM material. Detectors fabricated from material that was both ZR and ZL did not demonstrate gamma ray resolution, and operated mainly as counters. The poor spectroscopic performance is presently attributed to the inhomogeneity of the electrical properties of the ZR and ZL GaAs materials. Comparisons are made with detectors fabricated from VGF SI bulk GaAs. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. CARNEGIE MELLON UNIV,DEPT ELECT & COMP ENGN,PITTSBURGH,PA 15213. UNIV CALIF LOS ANGELES,DEPT MAT SCI & ENGN,LOS ANGELES,CA 90024. DETECTRONIX,LIVERMORE,CA 94550. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. USN,RES LAB,WASHINGTON,DC 20375. SOLID STATE ELECT DIRECTORATE,WRIGHT PATTERSON AFB,OH 45433. WRIGHT STATE UNIV,RES CTR,DAYTON,OH 45435. RP McGregor, DS (reprint author), SANDIA NATL LABS,MS-9162,LIVERMORE,CA 94550, USA. NR 19 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1996 VL 43 IS 3 BP 1397 EP 1406 DI 10.1109/23.507073 PN 2 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA UT044 UT WOS:A1996UT04400061 ER PT J AU Inderhees, SE Phlips, BF Kroeger, RA Johnson, WN Kinzer, RL Kurfess, JD Graham, B Gehrels, N AF Inderhees, SE Phlips, BF Kroeger, RA Johnson, WN Kinzer, RL Kurfess, JD Graham, B Gehrels, N TI Spectroscopy, imaging and Compton-scatter polarimetry with a germanium strip detector SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1995 Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY OCT 21-28, 1995 CL SAN FRANCISCO, CA ID GAMMA-RAY AB Germanium strip detectors combine the excellent energy resolution possible with germanium detectors with fine two-dimensional spatial resolution determined by orthogonal strip electrodes. We are testing a detector with an active volume of 5 x 5 x 1 cm(3) and a total of 50 electrodes, 25 on each side with a 2mm pitch. Potential astrophysics applications include use as a focal plane for a coded-aperture telescope in the energy range similar to 5-500 keV, as the focal plane of a grazing-incidence telescope in the similar to 5-100 keV band, or in a Compton scatter telescope. The utilization of germanium strip detectors for these applications requires proof of their performance capabilities in terms of energy and spatial resolution, and efficiencies for single and multi-pixel interactions. In this paper, we demonstrate the excellent spectroscopy and imaging performance of a 2mm pitch strip detector, and report on the results of Monte- Carlo simulations of photopeak efficiencies for single and multi-pixel interactions. These simulations show that 2-pixel interactions are a significant fraction of the photopeak efficiency in the 80 - 500 keV range. We demonstrate that these interactions can be used to measure linear polarization of a normally incident beam. C1 USN,RES LAB,WASHINGTON,DC 20375. GEORGE MASON UNIV,FAIRFAX,VA 22030. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP Inderhees, SE (reprint author), UNIV SPACE RES ASSOC,WASHINGTON,DC, USA. RI Gehrels, Neil/D-2971-2012; Johnson, Neil/G-3309-2014 NR 23 TC 16 Z9 16 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1996 VL 43 IS 3 BP 1467 EP 1471 DI 10.1109/23.507085 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA UT044 UT WOS:A1996UT04400073 ER PT J AU Phlips, BF Inderhees, SE Kroeger, RA Johnson, WN Kinzer, RL Kurfess, JD Graham, BL Gehrels, N AF Phlips, BF Inderhees, SE Kroeger, RA Johnson, WN Kinzer, RL Kurfess, JD Graham, BL Gehrels, N TI Performance of a compton telescope using position-sensitive germanium detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1995 Nuclear Science Symposium/Medical Imaging Conference (NSS/MIC) CY OCT 21-28, 1995 CL SAN FRANCISCO, CA AB We describe the use of position sensitive planar germanium detectors in a Compton telescope/camera. This Compton telescope achieves the very good energy resolution (Delta Etotal < 4 keV) associated with germanium detectors and good position resolution (2 mm. By combining a 25 x 25 strip (2 mm pitch) detector with a 5 x 5 strip detector (9 mm pitch), we created a telescope with 625 x 25 pixel combinations. Using this detector pair, we have reconstructed positions with an angular resolution of similar to 1 degree FWHM and 15 arcminute centroiding. Point sources are identified with less than 100 full energy events with simple image reconstruction. The angular resolution is currently limited by the uncertainty in the absolute position of the detectors and the size of the second detector pixels. We show the expected angular resolution when the pixel size no longer dominates the angular resolution and discuss proposed applications. C1 USN,RES LAB,WASHINGTON,DC 20375. GEORGE MASON UNIV,FAIRFAX,VA 22030. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP Phlips, BF (reprint author), UNIV SPACE RES ASSOC,WASHINGTON,DC, USA. RI Gehrels, Neil/D-2971-2012; Johnson, Neil/G-3309-2014 NR 6 TC 17 Z9 17 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD JUN PY 1996 VL 43 IS 3 BP 1472 EP 1475 DI 10.1109/23.507086 PN 2 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA UT044 UT WOS:A1996UT04400074 ER PT J AU Felch, K Blank, M Borchard, P Chu, TS Feinstein, J Jory, HR Lorbeck, JA Loring, CM Mizuhara, YM Neilson, JM Schumacher, R Temkin, RJ AF Felch, K Blank, M Borchard, P Chu, TS Feinstein, J Jory, HR Lorbeck, JA Loring, CM Mizuhara, YM Neilson, JM Schumacher, R Temkin, RJ TI Long-pulse and CW tests of a 110-GHz gyrotron with an internal, quasi-optical converter SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID DESIGN AB A high-power gyrotron, employing an internal converter that produces a Gaussian-like output mode, has been designed and tested. The tube employed a TE(22,6,1)-mode interaction cavity that was designed for operation at a frequency of 110 GHz, An internal converter, consisting of an advanced launcher design and four mirrors, produced a Gaussian mode that had a relatively uniform profile at the tube output window to minimize the peak power density. Tests on the tube resulted in output power levels of 680, 530, and 350 kW for pulse durations of 0.5, 2.0, and 10.0 s, respectively, Measurements of the temperature of the output window were made during the long-pulse tests, Output power levels of 1 MW were achieved under short-pulse (1 ms) operation and the tube was operated at CW power levels in excess of 100 kW. C1 USN,RES LAB,WASHINGTON,DC 20375. STANFORD UNIV,PALO ALTO,CA 94305. QUALCOMM INC,SAN DIEGO,CA 92121. VISTA RES,MT VIEW,CA 94042. VARIAN ASSOCIATES INC,PALO ALTO,CA 94303. MIT,CTR PLASMA FUS,CAMBRIDGE,MA 02139. RP Felch, K (reprint author), COMMUN & POWER IND,PALO ALTO,CA 94303, USA. NR 18 TC 57 Z9 57 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1996 VL 24 IS 3 BP 558 EP 569 DI 10.1109/27.532938 PG 12 WC Physics, Fluids & Plasmas SC Physics GA VE084 UT WOS:A1996VE08400003 ER PT J AU Hafizi, B Hirshfield, JL AF Hafizi, B Hirshfield, JL TI Theory of a rotating-mode coaxial infrared grating laser SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID FREE-ELECTRON LASER AB Analysis is presented for a novel interaction that makes possible a compact infrared grating laser configuration, The laser utilizes an annular axis encircling beam that is confined by an axial magnetic field and passes along a grating blazed axially on the center conductor of a coaxial resonator, A smooth cylindrical enter conductor completes the Fabry-Perot resonator to provide the necessary feedback for sustained oscillation, Linear analysis leads to an eigenvalue equation for cavity resonance frequencies, start-oscillation currents, and a gain-bandwidth relationship, The latter permits estimation of an upper bound on the ideal-beam power extraction efficiency, The nonlinear studies make use of analytical and numerical methods to gain a detailed understanding of electron motion in the presence of both axially focusing and radio frequency fields, and to determine the nonlinear efficiency. There is significant degradation of the interaction efficiency when the beam has finite annular thickness, Efficiency enhancement by means of a down-tapered axial held is demonstrated, A point design for lasing at similar to 160 mu m in the far-infrared, utilizing a 100-kV beam with a pitch angle of 55 degrees is presented, The start-oscillation current is a sensitive function of the resonator quality factor (or finesse); for a well-designed resonator, it is on the order of tens of Amperes. C1 OMEGA P INC,NEW HAVEN,CT 06520. YALE UNIV,DEPT PHYS,NEW HAVEN,CT 06520. RP Hafizi, B (reprint author), USN,RES LAB,ICARUS RES,WASHINGTON,DC 20375, USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1996 VL 24 IS 3 BP 758 EP 769 DI 10.1109/27.533078 PG 12 WC Physics, Fluids & Plasmas SC Physics GA VE084 UT WOS:A1996VE08400025 ER PT J AU Blank, M Freund, HP Jackson, RH Pershing, DE Taccetti, JM AF Blank, M Freund, HP Jackson, RH Pershing, DE Taccetti, JM TI Design of a low-voltage annular beam Ku-band free-electron laser SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID 1ST OPERATION AB A nonlinear analysis of an annular beam free-electron laser (FEL) with a helical wiggler and axial guide field is presented. An annular beam has the advantage over a solid beam of reduced de self-fields, facilitating beam transport in short period wigglers, The annular beam geometry also permits use of a central structure to enhance the wiggler field, which tends to decrease as the period is decreased. Two configurations of the waveguide and wiggler were theoretically investigated. First, an annular beam interacting with a TE(11) cylindrical waveguide mode in the presence of a helical wiggler was studied, Next, the interaction with a coaxial TE(11) mode in the presence a novel coaxial wiggler with both inner and enter bifilar helical current windings was examined, The beam under consideration is nominally 55 kV and 5 A and tbe wiggler period is 0.9 cm, An axial guide field up to 4 kG was used. The beam and wiggler parameters correspond to grazing incidence with the TE(11) mode In Ku-band, Nonlinear slow-time-scale simulations show that for an ideal beam, efficiencies greater than 10% can be achieved with instantaneous bandwidths in excess of 20%. The effect of axial energy spread on interaction efficiency is examined. C1 SCI APPLICAT INT CORP,MCLEAN,VA 22102. MISSION RES CORP,NEWINGTON,VA 22122. UNIV MARYLAND,COLLEGE PK,MD 20742. RP Blank, M (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1996 VL 24 IS 3 BP 796 EP 801 DI 10.1109/27.533081 PG 6 WC Physics, Fluids & Plasmas SC Physics GA VE084 UT WOS:A1996VE08400028 ER PT J AU Freund, HP Zaidman, EG Kodis, MA Vanderplaats, NR AF Freund, HP Zaidman, EG Kodis, MA Vanderplaats, NR TI Linearized field theory of a dielectric-loaded helix traveling wave tube amplifier SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article AB A linearized relativistic field theory of a helix traveling wave tube (TWT) is presented for a configuration where either a thin annular beam or a solid beam propagates through a sheath helix enclosed within a loss-free wall in which the gap between the helix and the outer wall is filled with a dielectric, A linear analysis of the interaction is solved subject to the boundary conditions imposed by the beam, helix, and wail, In the case of the annular beam, the electrons are assumed to be strongly magnetized. In contrast, the effect of variations in the axial magnetic field are included in the electron dynamics for the solid beam analysis, Determinantal dispersion equations are obtained for the azimuthally symmetric modes which implicitly includes beam space-charge effects without recourse to a heuristic model of the space-charge field. Numerical solutions of the dispersion equations are discussed and compared with experiments. C1 USN, RES LAB, VACUUM ELECT BRANCH, WASHINGTON, DC 20375 USA. RP Freund, HP (reprint author), SCI APPLICAT INT CORP, MCLEAN, VA 22102 USA. NR 14 TC 16 Z9 16 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1996 VL 24 IS 3 BP 895 EP 904 DI 10.1109/27.533093 PG 10 WC Physics, Fluids & Plasmas SC Physics GA VE084 UT WOS:A1996VE08400040 ER PT J AU Gold, SH Kinkead, AK Fliflet, AW Hafizi, B Manheimer, WM AF Gold, SH Kinkead, AK Fliflet, AW Hafizi, B Manheimer, WM TI Initial operation of a high-power frequency-doubling X-band magnicon amplifier SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID DEFLECTION; DESIGN; BEAM AB This paper reports the initial high-power operation of a frequency-doubling magnicon amplifier at 11.120 GHz, The deflection cavities operate at 5.560 GHz. The device is operating in a single-pulse mode at 650 kV and similar to 225 A, using a 5.5-mm diameter beam from a plasma cathode, at a magnetic field of 6.7-8.2 kG. In order to overcome a gain saturation problem in the deflection cavities caused by plasma loading, the penultimate deflection cavity is operated very close to self-oscillation. The typical output pulselength is 100 ns full width at half maximum (FWHM), and is limited by RF breakdown of the penultimate cavity. Based on the measured far-field antenna pattern and absolute calibration of all microwave components, the measured output power is 14 MW (+/- 3 dB), corresponding to an efficiency of similar to 10%. C1 SACHS FREEMAN ASSOCIATES INC,LANDOVER,MD 20785. ICARUS RES,BETHESDA,MD 20824. RP Gold, SH (reprint author), USN,RES LAB,DIV PLASMA PHYS,BEAM PHYS BRANCH,WASHINGTON,DC 20375, USA. NR 12 TC 7 Z9 7 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1996 VL 24 IS 3 BP 947 EP 956 DI 10.1109/27.533100 PG 10 WC Physics, Fluids & Plasmas SC Physics GA VE084 UT WOS:A1996VE08400047 ER PT J AU Fliflet, AW Gold, SH AF Fliflet, AW Gold, SH TI Mode competition in fourth-harmonic magnicon amplifiers SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID GYROTRON OSCILLATORS; MULTIMODE SIMULATION; OUTPUT CAVITY; DEFLECTION; DESIGN AB In the magnicon RF amplifier, the drive and gain cavities are cylindrical deflection cavities which operate in a rotating TM(110)-mode and spin up an electron beam to high transverse momentum, As a result of the rotating-mode interaction, the electron beam entry point into the output cavity rotates about the aids at the drive frequency, The gyrotron-like output cavity can be operated at m times the drive frequency by using a mode with an azimuthal index of m, as this mode rotates at m(-1) times its RF frequency, thus maintaining synchronism with the electron beam, Previous frequency-multiplying magnicons have used m = 2; in this paper it is shown that magnicons with m = 4 may be practical, provided one also operates the output cavity at the m/2 harmonic of the cyclotron frequency, Operation at higher harmonics lowers the frequency of the deflection cavities allowing lower RF fields, reducing cavity breakdown problems; lower magnetic fields, reducing magnet cost and complexity; and a larger electron beam, relaxing beam quality constraints, On the other hand, higher order azimuthal-index magnicon modes interacting at higher order cyclotron interactions are subject to competition with nonsynchronous (gyrotron) modes and are more sensitive to electron beam scanning angle spread, A time-dependent multimode gyrotron code has been modified to examine competition in the output cavity between the phase-synchronous operating mode and other nonsynchronous modes which interact via the conventional gyrotron interaction, Calculations have been carried out for fourth-harmonic magnicons with TM(110) and TE(411) mode output cavities and include the effects of mode competition with nonsynchronous modes as well as a spread in entry-point angles of the scanning electron beam. RP Fliflet, AW (reprint author), USN,RES LAB,DIV PLASMA PHYS,BEAM PHYS BRANCH,WASHINGTON,DC 20375, USA. NR 18 TC 7 Z9 7 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1996 VL 24 IS 3 BP 957 EP 963 DI 10.1109/27.533101 PG 7 WC Physics, Fluids & Plasmas SC Physics GA VE084 UT WOS:A1996VE08400048 ER PT J AU Kodis, MA Jensen, KL Zaidman, EG Goplen, B Smithe, DN AF Kodis, MA Jensen, KL Zaidman, EG Goplen, B Smithe, DN TI Operation and optimization of gated field emission arrays in inductive output amplifiers SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID PARAMETERS AB In an inductive output amplifier, an emission-gated electron beam induces high-frequency fields in an output circuit via displacement current, not convection current. Emission-gated electron beams experience strong interactions when traversing a resonant or synchronous electromagnetic field, and this strong interaction is responsible for both the interesting nonlinear physics and the attractive efficiency and compactness of emission-gated amplifiers, Field emission cathodes, due to their extremely low electron transit time and high transconductance, offer the opportunity to extend the advantages of emission gating into C and X band. This paper presents design criteria for the joint optimization of the held emission array (FEA) structure and the RF input and output circuits of inductive output amplifiers, We find that while output circuits yielding net efficiencies of 50% or greater are well within the state of the art, the gain is likely to be moderate (10-20 dB), With today's FEA performance, a desirable operating regime is achievable, yielding a new class of compact, highly efficient, and moderate gain power booster amplifiers. C1 MISSION RES CORP,NEWINGTON,VA 22122. RP Kodis, MA (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Jensen, Kevin/I-1269-2015 OI Jensen, Kevin/0000-0001-8644-1680 NR 33 TC 19 Z9 19 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1996 VL 24 IS 3 BP 970 EP 981 DI 10.1109/27.533103 PG 12 WC Physics, Fluids & Plasmas SC Physics GA VE084 UT WOS:A1996VE08400050 ER PT J AU Liu, CB Antonsen, TM Levush, B AF Liu, CB Antonsen, TM Levush, B TI Simulation of the velocity spread in magnetron injection guns SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID SPACE-CHARGE INSTABILITIES; ELECTRON-BEAMS; GYROTRON BEAMS; CYCLOTRON AB The velocity spread associated with phase mixing due to de space charge in a magnetron injection gun (MIG) is investigated. A simple model is introduced to describe the mixing process. Simulations are performed by using the results of the EGUN trajectory calculation for initial conditions at the entrance of the drift region, Results for a 170 GHz gun are obtained and compared with EGUN simulations, This new model provides a more accurate and efficient approach for analyzing the velocity spread due to mixing in MIG's. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Liu, CB (reprint author), UNIV MARYLAND,INST PLASMA RES,COLLEGE PK,MD 20742, USA. RI Antonsen, Thomas/D-8791-2017 OI Antonsen, Thomas/0000-0002-2362-2430 NR 13 TC 14 Z9 15 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1996 VL 24 IS 3 BP 982 EP 991 DI 10.1109/27.533104 PG 10 WC Physics, Fluids & Plasmas SC Physics GA VE084 UT WOS:A1996VE08400051 ER PT J AU Lawson, W Garven, M Nusinovich, GS AF Lawson, W Garven, M Nusinovich, GS TI On the design of electron guns for cyclotron resonance masers utilizing trochoidal electron beams (trochotrons) SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID MAGNETRON INJECTION GUN; MODE COMPETITION; GYROTRON AB The properties of crossed-field electron guns which are capable of providing the required trochoidal beams for efficient cyclotron resonance interaction in the trochotron configuration are analyzed, A discussion of the beam parameters that are used to characterize the device performance is included in a general description of the operation of these guns, Two concrete designs are presented and are used to demonstrate the performance capabilities of these devices with respect to the beam self-fields, the externally applied electric and magnetic fields, and the electrode geometry. It is shown that these devices, which; typically generate beams with large ratios of perpendicular to parallel (drift) velocity, are capable of producing extremely small drift velocity spreads over a wide range of parameters. C1 UNIV MARYLAND,DEPT ELECT ENGN,COLLEGE PK,MD 20742. USN,RES LAB,VACUUM ELECT BRANCH,WASHINGTON,DC 20375. RP Lawson, W (reprint author), UNIV MARYLAND,INST PLASMA RES,COLLEGE PK,MD 20742, USA. NR 21 TC 1 Z9 1 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1996 VL 24 IS 3 BP 999 EP 1004 DI 10.1109/27.533106 PG 6 WC Physics, Fluids & Plasmas SC Physics GA VE084 UT WOS:A1996VE08400053 ER PT J AU Fliflet, AW Bruce, RW Kinkead, AK Fischer, RP Lewis, D Rayne, R Bender, B Kurihara, LK Chow, GM Schoen, PE AF Fliflet, AW Bruce, RW Kinkead, AK Fischer, RP Lewis, D Rayne, R Bender, B Kurihara, LK Chow, GM Schoen, PE TI Application of microwave heating to ceramic processing: Design and initial operation of a 2.45-GHz single-mode furnace SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article ID POWDERS AB High-power microwave and millimeter-wave sources are currently being applied to ceramic processing studies at the Naval Research Laboratory (NRL), A single-mode cavity microwave furnace, operating in the TE(103) mode at 2.45 GHz, is operational rind is being used to investigate sintering of nanocrystalline ceramics. This paper reports the design of the 2,45-GHz furnace and its use in initial microwave sintering experiments on nanocrystalline alumina and titania compacts. The high purity Al2O3 and TiO2 nanocrystalline powders used in the sintering experiments were prepared by the sol-gel method, These powders were first uniaxially pressed to 14 MPa, cold isostatically pressed (CIP'ed) to various pressures greater than or equal to 420 MPa, and finally sectioned into wafers, The density of the green compacts was 30 to 38% theoretical density (TD), The compacts were placed in insulating fiberboard caskets which were sufficiently lossy to provide hybrid heating at room temperature, The compacts were heated in the microwave furnace for up to three hours at temperatures less than or equal to 1720 degrees C, The temperature of the workpiece was monitored using an optical pyrometer, Final densities up to 80% TD have been obtained to date for Al2O3 and up to 52% TD for TiO2. The sintered compacts were characterized by X-ray diffraction and by scanning electron microscopy (SEM) to determine the phase and grain size. C1 SACHS FREEMAN ASSOCIATES INC,LANDOVER,MD 20785. USN,RES LAB,CTR BIOMOL SCI & ENGN,MECH MAT BRANCH,WASHINGTON,DC 20375. GEORGETOWN UNIV,WASHINGTON,DC 20057. USN,RES LAB,CTR BIOMOL SCI & ENGN,WASHINGTON,DC 20375. RP Fliflet, AW (reprint author), USN,RES LAB,DIV PLASMA PHYS,BEAM PHYS BRANCH,CTR BIOMOLEC SCI & ENGN,WASHINGTON,DC 20375, USA. NR 22 TC 20 Z9 21 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD JUN PY 1996 VL 24 IS 3 BP 1041 EP 1049 DI 10.1109/27.533111 PG 9 WC Physics, Fluids & Plasmas SC Physics GA VE084 UT WOS:A1996VE08400058 ER PT J AU Wheless, GH Lascara, CM ValleLevinson, A Brutzman, DP Sherman, W Hibbard, WL Paul, BE AF Wheless, GH Lascara, CM ValleLevinson, A Brutzman, DP Sherman, W Hibbard, WL Paul, BE TI The Chesapeake Bay virtual environment (CBVE): Initial results from the prototypical system SO INTERNATIONAL JOURNAL OF SUPERCOMPUTER APPLICATIONS AND HIGH PERFORMANCE COMPUTING LA English DT Article ID ATLANTIC BIGHT; CIRCULATION; OCEAN AB The authors develop a modeling framework that integrates hydrodynamic circulation models and various biological models with the computer visualization paradigm of the virtual world to investigate coupled linkages between physics and biology within the Chesapeake Bay ecosystem. These initial efforts, demonstrated at Supercomputing '95 on the ImmersaDesk, focus on how environmental forcing affects the flow in the Chesapeake Bay and how biological distributions change in response to this circulation. The authors use the virtual environment to visualize time-dependent, three-dimensional, multivariate ecological data sets, This visualization process greatly aids in the interpretation and synthesis of the supercomputer-based numerical simulations and provides new insights into the ecological consequences of physical and biological interactions. Viewing, navigating through, and interacting with multidimensional fields (e.g,, salinity, circulation vectors, larval fish distributions) in the virtual environment provides a sense of presence that greatly improves one's ability to understand inherently complex processes, thereby advancing the implementation of coupled physical-biological models, The use of data sonification to portray modeled data in the virtual environment also improves one's ability to interpret the numerical results. C1 USN,POSTGRAD SCH,MONTEREY,CA 93943. NATL CTR SUPERCOMP APPLICAT,CHAMPAIGN,IL 61820. UNIV WISCONSIN,CTR SPACE SCI & ENGN,MADISON,WI 53706. RP Wheless, GH (reprint author), OLD DOMINION UNIV,CTR COASTAL PHYS OCEANOG,768 52ND ST,NORFOLK,VA 23529, USA. NR 32 TC 7 Z9 7 U1 0 U2 0 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 SN 1078-3482 J9 INT J SUPERCOMPUT AP JI Int. J. Supercomput. Appl. High Perform. Comput. PD SUM-FAL PY 1996 VL 10 IS 2-3 BP 199 EP 210 DI 10.1177/109434209601000207 PG 12 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications SC Computer Science GA WA010 UT WOS:A1996WA01000007 ER PT J AU Barlow, JG AF Barlow, JG TI Securing command of the sea: NATO naval planning, 1948-1954 - Maloney,SM SO JOURNAL OF AMERICAN HISTORY LA English DT Book Review RP Barlow, JG (reprint author), USN,HIST CTR,WASHINGTON,DC, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ORGAN AMER HISTORIANS PI BLOOMINGTON PA 112 N BRYAN ST, BLOOMINGTON, IN 47401 SN 0021-8723 J9 J AM HIST JI J. Am. Hist. PD JUN PY 1996 VL 83 IS 1 BP 282 EP 282 DI 10.2307/2945608 PG 1 WC History SC History GA UT488 UT WOS:A1996UT48800142 ER PT J AU Tritt, TM Nolas, GS Slack, GA Ehrlich, AC Gillespie, DJ Cohn, JL AF Tritt, TM Nolas, GS Slack, GA Ehrlich, AC Gillespie, DJ Cohn, JL TI Low-temperature transport properties of the filled and unfilled IrSb3 skutterudite system SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THERMAL-CONDUCTIVITY; LAFE4P12 STRUCTURE; SINGLE-CRYSTALS; RARE-EARTH; PHOSPHIDES AB We have measured the electrical resistivity, rho, thermoelectric power, alpha, and thermal conductivity, kappa, of the skutterudite material IrSb3 in a temperature range from 300 down to 4 K. It is found that the electrical resistivity and thermopower decrease monotonically as the temperature is reduced to 50-60 K. Below approximately 60 K the resistivity rises in a semiconducting manner. It appears the thermopower exhibits a large phonon drag peak at around 20 K and then falls towards zero. The thermal conductivity increases rapidly as the temperature is decreased with a maximum at around 20 K, corresponding to the peak in the thermopower. We will discuss these results and compare them to higher temperature data from G. A. Slack and V. G. Tsoukala [(lrSb3) J. Appl. Phys. 76, 1635 (1994)]. We have also measured some of the so-called ''filled skutterudites,'' Ir4LaGe3Sb9, Ir4NdGe3Sb9 and Ir(4)SaGe(3)Sb(9). The thermoelectric properties of these materials are considerably different than those of the unfilled sample. The thermopower is considerably lower and the resistivity is a factor of 2-4 times higher than the unfilled sample at room temperature. The thermal conductivity is markedly reduced by the filling, as much as a factor of 20 reduction for some of the systems. (C) 1996 American Institute of Physics. C1 RENSSELAER POLYTECH INST,DEPT PHYS,TROY,NY 12100. UNIV MIAMI,DEPT PHYS,CORAL GABLES,FL 33124. RP Tritt, TM (reprint author), USN,RES LAB,MAT PHYS BRANCH,WASHINGTON,DC 20375, USA. NR 32 TC 52 Z9 55 U1 3 U2 23 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 1 PY 1996 VL 79 IS 11 BP 8412 EP 8418 DI 10.1063/1.362515 PG 7 WC Physics, Applied SC Physics GA UN852 UT WOS:A1996UN85200041 ER PT J AU Guha, S Steiner, P Lang, W AF Guha, S Steiner, P Lang, W TI Resonant Raman scattering and photoluminescence studies of porous silicon membranes SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SPECTRA; SIZE AB Raman scattering measurements as a function of excitation wavelength are conducted on a 55-mu m-thick porous silicon (PS) membrane of an approximate porosity of 70%. A narrowing of the Si-Si phonon peak with increasing excitation wavelength is observed. We attribute this to a resonance of the excitation energy with the electronic states of nanocrystallites in PS. We estimate the size of silicon particles from the shift and broadening of the phonon band. The absorption band edge is next blue shifted by annealing the sample at 300 and 500 degrees C. A collapse of the nanostructure with a decrease in particle size is observed. The photoluminescence (PL) spectra exhibit a red shift of the PL band upon annealing. We also estimate the size of silicon particles from the PL peak. (C) 1996 American Institute of Physics. C1 FRAUNHOFER INST,MUNICH,GERMANY. RP Guha, S (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Lang, Walter/G-3835-2011; OI Lang, Walter/0000-0002-9813-5231 NR 14 TC 32 Z9 33 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 1 PY 1996 VL 79 IS 11 BP 8664 EP 8668 DI 10.1063/1.362491 PG 5 WC Physics, Applied SC Physics GA UN852 UT WOS:A1996UN85200084 ER PT J AU Imagawa, A Hanafusa, T Itoh, N Miyagawa, J Nakajima, H Namba, M Kuwajima, M Tamura, S Kawata, S Matsuzawa, Y Harlan, DM AF Imagawa, A Hanafusa, T Itoh, N Miyagawa, J Nakajima, H Namba, M Kuwajima, M Tamura, S Kawata, S Matsuzawa, Y Harlan, DM TI Islet-infiltrating T lymphocytes in insulin-dependent diabetic patients express CD80 (B7-1) and CD86 (B7-2) SO JOURNAL OF AUTOIMMUNITY LA English DT Article; Proceedings Paper CT 14th Immunology of Diabetes Workshop - Immunology of Diabetes 95 CY OCT 31-NOV 03, 1995 CL ORVIETO, ITALY SP Immunol Diabetes Soc DE IDDM; co-stimulatory factor; insulins; pancreas biopsy; immunohistochemistry ID PANCREAS BIOPSY SPECIMENS; MELLITUS; RECEPTOR; ACTIVATION; MOLECULES; ANTIGENS; CTLA-4 AB Insulin-dependent diabetes mellitus (IDDM) results mainly from T cell mediated pancreatic beta cell destruction. To fully activate antigen specific T cells, current evidence suggests that two signals are required. One signal is delivered via the antigen specific T cell receptor (TCR) when engaged by major histocompatibility complex presented antigen (MHC:Ag), the other via the T cell's CD28 when engaged by CD80/86. Recent studies have demonstrated that transgenic mice expressing CD80 on their pancreatic beta cells are susceptible to autoimmune beta cell destruction. To further explore whether CD80/86 expression plays a role in IDDM pathogenesis, we analysed pancreatic biopsy specimens from 16 recent-onset IDDM patients (13 men and 3 women; age 29.7+/-8.8 years) for CD80/86 expression. While no biopsy revealed any islet cell specific CD80 or CD86 expression, biopsies from six of the nine patients with insulitis revealed both CD80 and CD86 expression on the islet infiltrating cells. Triple immunofluorescent staining for CD80/86, CD3, and glucagon revealed that the CD80/86-positive cells were also CD3-positive. Of the CD3-positive cells, 19.4% expressed CD80 and 21.7% expressed CD86. CD80 and CD86-positive cells were similarly distributed throughout the inflamed islets. These data suggest that CD28 engagement with CD80/86 may play a pathogenic role in the beta cell destruction underlying IDDM. (C) 1996 Academic Press Limited C1 USN,MED RES INST,IMMUNE CELL BIOL PROGRAM,BETHESDA,MD 20889. RP Imagawa, A (reprint author), OSAKA UNIV,SCH MED,DEPT INTERNAL MED 2,2-2 YAMADAOKA,SUITA,OSAKA 565,JAPAN. NR 25 TC 20 Z9 20 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0896-8411 J9 J AUTOIMMUN JI J. Autoimmun. PD JUN PY 1996 VL 9 IS 3 BP 391 EP 396 DI 10.1006/jaut.1996.0053 PG 6 WC Immunology SC Immunology GA UT441 UT WOS:A1996UT44100013 PM 8816976 ER PT J AU Yao, RJ Guerry, P AF Yao, RJ Guerry, P TI Molecular cloning and site-specific mutagenesis of a gene involved arylsulfatase production in Campylobacter jejuni SO JOURNAL OF BACTERIOLOGY LA English DT Article ID KLEBSIELLA-AEROGENES; ANTIGENIC VARIATION; ESCHERICHIA-COLI; EXPRESSION; VECTORS AB The arylsulfatase gene from Campylobacter jejuni 81-176 encodes a predicted protein of 69,293 Da which shows no sequence similarity with other known arylsulfatases. The gene hybridizes to other Ast(+) strains of C. jejuni and Campylobacter sputorum subsp. bubulus, as well as to many Ast(-) strains of C. jejuni. C1 USN,MED RES INST,ENTER PROGRAM,BETHESDA,MD 20814. NR 25 TC 38 Z9 39 U1 0 U2 3 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD JUN PY 1996 VL 178 IS 11 BP 3335 EP 3338 PG 4 WC Microbiology SC Microbiology GA UN518 UT WOS:A1996UN51800045 PM 8655516 ER PT J AU Butcher, RJ Gilardi, RD George, C FlippenAnderson, J AF Butcher, RJ Gilardi, RD George, C FlippenAnderson, J TI Distortions in nitramine substituted cubanes: The structures of N,N'-dinitro-1,4-diaminocubane, N,N'-dinitro-N,N'-(2-pyridyl)-1,4-diaminocubane, and 1,2,4,7-tetrakis(N-methoxycarbonylnitramino)cubane SO JOURNAL OF CHEMICAL CRYSTALLOGRAPHY LA English DT Article DE nitramine structures; cubane structures; nitramine substituted cubanes ID SYSTEMATIC SUBSTITUTION; N,N-DIMETHYLNITRAMINE; PHENYLCUBANES; CHEMISTRY; NUCLEUS AB The structures of three nitramine substituted cubane molecules, N,N'-dinitro-1,4-diaminocubane (1), N,N'-dinitro-N,N'-(2-pyridyl)-1,4-diaminocubane (2), and 1,2,4,7-Tetrakis(N-methoxycarbonylnitramino)-cubane (3), have been determined. 1 crystallized in the space group P2(1)/a with cell dimensions a = 6.545(1), b = 9.331(1), c = 7.459(1) Angstrom, beta = 105.80(1), 2 crystallized in the monoclinic space group P2(1)/a with cell dimensions a = 7.545(2), b = 8.697(3), c = 12.406(4 Angstrom, beta = 96.28(3)degrees, while 3 crystallized in the monoclinic space group P2(1)/c with cell dimensions a = 10.866(3), b = 6.866(2), c = 16.167(6) Angstrom, beta = 108.79(3)degrees. The metrical parameters of the cubane skeleton showed no significant deviations from those found in other similarly substituted cubane molecules. For 2 and 3 there were considerable distortions of the nitramine moiety from planarity in contrast to 1 where the nitramine moiety was almost exactly planar. The bond distances and angles for the nitramine group in 1 indicates a substantial introduction of double bond character into the N-N bond in 1, achieved by delocalization of the amine pi lone pair, compared with 2 and 3. C1 USN,RES LAB,STRUCT MATTER LAB,WASHINGTON,DC 20375. RP Butcher, RJ (reprint author), HOWARD UNIV,DEPT CHEM,525 COLL ST NW,WASHINGTON,DC 20059, USA. RI G, Neela/H-3016-2014 NR 35 TC 5 Z9 5 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 1074-1542 J9 J CHEM CRYSTALLOGR JI J. Chem. Crystallogr. PD JUN PY 1996 VL 26 IS 6 BP 381 EP 388 DI 10.1007/BF01665815 PG 8 WC Crystallography; Spectroscopy SC Crystallography; Spectroscopy GA VC297 UT WOS:A1996VC29700001 ER PT J AU Johnstone, PAS Rohde, DC Swartz, RE Fetter, JE Wexner, SD AF Johnstone, PAS Rohde, DC Swartz, RE Fetter, JE Wexner, SD TI Port site recurrences after laparoscopic and thoracoscopic procedures in malignancy SO JOURNAL OF CLINICAL ONCOLOGY LA English DT Review ID METASTASIS FOLLOWING LAPAROSCOPY; LARGE-BOWEL-CANCER; HEPATOCELLULAR-CARCINOMA; INCISIONAL RECURRENCE; GALLBLADDER CARCINOMA; PANCREATIC-CARCINOMA; CERVICAL-CARCINOMA; ASSISTED COLECTOMY; SURGERY; CHOLECYSTECTOMY AB Purpose and Methods: A review of the literature was performed to determine the number of cases of port site recurrences (PSR) after laparoscopy or thoracoscopy. CANCERLINE and MEDLINE were searched, as were citings from retrieved and related papers. Results: There have been 35 reported cases of PSR after laparoscopic colectomy for colorectal carcinoma, and 23 cases after thoracoscopic procedures for lung neoplasms, All of these have been reported since 1993. Since 1991, 12 cases have been described after laparoscopic cholecystectomy of unsuspected gallbladder carcinoma, and another case after biopsy of a known gallbladder carcinoma. Ten cases of PSR have been reported after laparoscopic procedures for ovarian lesions, often in the presence of peritoneal seeding at diagnosis. Other rare PSRs have been documented after several procedures in various malignancies. Conclusion Enrollment of patients onto the ongoing intergroup study evaluating open versus laparoscopic resection of colon cancer should be encouraged. Until valid prospective data on PSR frequency are available, laparoscopic or thoracoscopic resection of malignancy off-protocol should be undertaken with circumspection. C1 UNIV CALIF SAN DIEGO, SAN DIEGO, CA 92103 USA. SUBURBAN HOSP, BETHESDA, MD USA. UNIFORMED SERV UNIV HLTH SCI, BETHESDA, MD 20814 USA. CLEVELAND CLIN FLORIDA, DEPT COLORECTAL SURG, FT LAUDERDALE, FL USA. RP Johnstone, PAS (reprint author), USN, MED CTR, DEPT CLIN INVEST, SAN DIEGO, CA 92134 USA. NR 84 TC 154 Z9 158 U1 0 U2 1 PU AMER SOC CLINICAL ONCOLOGY PI ALEXANDRIA PA 2318 MILL ROAD, STE 800, ALEXANDRIA, VA 22314 USA SN 0732-183X EI 1527-7755 J9 J CLIN ONCOL JI J. Clin. Oncol. PD JUN PY 1996 VL 14 IS 6 BP 1950 EP 1956 PG 7 WC Oncology SC Oncology GA UP725 UT WOS:A1996UP72500024 PM 8656265 ER PT J AU Tompa, GS Li, YB Agassi, D Kim, SI Hong, SK AF Tompa, GS Li, YB Agassi, D Kim, SI Hong, SK TI Mg2Si buffer layers on Si(100) prepared by a simple evaporation method SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE buffer layers; Mg2Si; Si; thermal evaporation ID BEAM EPITAXIAL-GROWTH; MU-M; BAND-STRUCTURE; SUPERLATTICES; INSB; GAAS; PHOTOLUMINESCENCE; LASERS; SI AB The formation of Mg2Si(100), a(o) = 6.39 Angstrom, on Si(100) substrates has been investigated. Mg was first evaporated onto Si(100) surfaces and Mg2Si (100) films were formed in a subsequent annealing process. The Mg2Si layers were characterized by x-ray diffraction and transmission electron microscopy analysis. Optical and scanning electron microscopy analysis show the surface morphology to be smooth. The films are stable under thermal cycling and exhibit low resistivity. Epitaxial films of Mg2Si on Si(100) could be an ideal substrate for mercury cadmium telluride and antimonide based III-V semiconductor for mid-infrared devices because of its close lattice matching (the lattice misfit factor is less than 1.5%). C1 USN,CTR SURFACE WARFARE,SILVER SPRING,MD 20903. STEVENS INST TECHNOL,HOBOKEN,NJ 07030. RP Tompa, GS (reprint author), STRUCT MAT IND INC,PISCATAWAY,NJ 08854, USA. NR 29 TC 5 Z9 9 U1 0 U2 5 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD JUN PY 1996 VL 25 IS 6 BP 925 EP 929 DI 10.1007/BF02666725 PG 5 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA UQ174 UT WOS:A1996UQ17400001 ER PT J AU Weng, NP Levine, BL June, CH Hodes, RJ AF Weng, NP Levine, BL June, CH Hodes, RJ TI Regulated expression of Telomerase activity in human T lymphocyte development and activation SO JOURNAL OF EXPERIMENTAL MEDICINE LA English DT Article ID CALCIUM IONOPHORES; HUMAN FIBROBLASTS; CYCLOSPORINE-A; HERBIMYCIN-A; SIGNAL; INHIBITOR AB Telomerase, a ribonucleoprotein that is capable of synthesizing telomeric repeats, is expressed in germline and malignant cells, and is absent in most normal human somatic cells. The selective expression of telomerase has thus been proposed to be a basis for the immortality of the germline and of malignant cells. In the present study, telomerase activity was analyzed in normal human T lymphocytes. It was found that telomerase is expressed at a high level in thymocyte subpopulations, at an intermediate level in tonsil T lymphocytes, and at a low to undetectable level in peripheral blood T lymphocytes. Moreover, telomerase activity is highly inducible in peripheral T lymphocytes by activation through CD3 with or without CD28 costimulation, or by stimulation with phorbol myristate acetate (PMA)/ionomycin. The induction of telomerase by anti-CDS plus anti-CD28 (anti-CD3/CD28) stimulation required RNA and protein synthesis, and was blocked by herbimycin A, an inhibitor of Src protein tyrosine kinases. The immunosuppressive drug cyclosporin A selectively inhibited telomerase induction by PMA/ionomycin and by anti-CD3, but not by anti-CD3/CD28. Although telomerase activity in peripheral T lymphocytes was activation dependent and correlated with cell proliferation, it was not cell cycle phase restricted. These results indicate that the expression of telomerase in normal human T lymphocytes is both developmentally regulated and activation induced. Telomerase may thus play a permissive role in T cell development and in determining the capacity of lymphoid cells for cell division and clonal expansion. C1 NIA,NIH,BETHESDA,MD 20892. USN,MED RES INST,IMMUNE CELL BIOL PROGRAM,BETHESDA,MD 20889. RP Weng, NP (reprint author), NCI,EXPTL IMMUNOL BRANCH,NIH,BLDG 10,ROOM 4-B17,BETHESDA,MD 20892, USA. RI Levine, Bruce/D-1688-2009 NR 48 TC 297 Z9 311 U1 0 U2 4 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 222 E 70TH STREET, NEW YORK, NY 10021 SN 0022-1007 J9 J EXP MED JI J. Exp. Med. PD JUN 1 PY 1996 VL 183 IS 6 BP 2471 EP 2479 DI 10.1084/jem.183.6.2471 PG 9 WC Immunology; Medicine, Research & Experimental SC Immunology; Research & Experimental Medicine GA UT401 UT WOS:A1996UT40100008 PM 8676067 ER PT J AU Saha, B Harlan, DM Lee, KP June, CH Abe, R AF Saha, B Harlan, DM Lee, KP June, CH Abe, R TI Protection against lethal toxic shock by targeted disruption of the CD28 gene SO JOURNAL OF EXPERIMENTAL MEDICINE LA English DT Article ID T-CELL ACTIVATION; STAPHYLOCOCCAL ENTEROTOXINS; ANTIGEN; SUPERANTIGENS; EXPRESSION; PROLIFERATION; REQUIREMENTS; LYMPHOCYTES; LYMPHOKINE; MOLECULES AB Toxic shock syndrome (TSS) is a multi system disorder resulting h-om superantigen-mediated cytokine production. Nearly 90% of the clinical cases of TSS arise due to an exotoxin, toxic shock syndrome toxin-1 (TSST-1), elaborated by toxigenic strains of Staphylococcus aureus. It is clearly established that besides antigen-specific signals a variety of costimulatory signals are required for full T cell activation. However, the nature and potential redundancy of costimulatory signals are incompletely understood, particularly with regards to superantigen-mediated T cell activation in vivo. Here we report that CD28-deficient mice (CD28-/-) are completely resistant to TSST-1-induced lethal TSS while CD28 (+/-) littermate mice were partially resistant to TSST-1. The mechanism for the resistance of the CD28 (-/-) mice was a complete abrogation of TNF-ol accumulation in the serum and a nearly complete (90%) impairment of IFN-gamma secretion in response to TSST-1 injection. In contrast, the serum level of IL-2 was only moderately influenced by the variation of CD28 expression. CD28 (-/-) mice retained sensitivity to TNF-alpha as demonstrated by equivalent lethality after cytokine injection. These findings establish an essential requirement for CD28 costimulatory signals in TSST-1-induced TSS. The hierarchy of TSST-1 resistance among CD28 wild-type (CD28+/+), CD28 heterozygous (CD28+/-), and CD28-/- mice suggests a gene-dose effect, implying that the levels of T cell surface CD28 expression critically regulate superantigen-mediated costimulation. Finally, as these results demonstrate the primary and non-redundant role of CD28 receptors in the initiation of the in vivo cytokine cascade, they suggest therapeutic approaches for superantigen-mediated immunopathology. C1 USN,MED RES INST,IMMUNE CELL BIOL PROGRAM,BETHESDA,MD 20889. SCI UNIV TOKYO,RES INST BIOL SCI,TOKYO 162,JAPAN. NR 32 TC 61 Z9 62 U1 0 U2 1 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 222 E 70TH STREET, NEW YORK, NY 10021 SN 0022-1007 J9 J EXP MED JI J. Exp. Med. PD JUN 1 PY 1996 VL 183 IS 6 BP 2675 EP 2680 DI 10.1084/jem.183.6.2675 PG 6 WC Immunology; Medicine, Research & Experimental SC Immunology; Research & Experimental Medicine GA UT401 UT WOS:A1996UT40100030 PM 8676089 ER PT J AU Luck, SJ Hillyard, SA Mouloua, M Hawkins, HL AF Luck, SJ Hillyard, SA Mouloua, M Hawkins, HL TI Mechanisms of visual-spatial attention: Resource allocation or uncertainty reduction? SO JOURNAL OF EXPERIMENTAL PSYCHOLOGY-HUMAN PERCEPTION AND PERFORMANCE LA English DT Article ID RAPID PERFORMANCE IMPROVEMENT; PRECUE TARGET DELAYS; FEATURE INTEGRATION; SELECTIVE ATTENTION; PERIPHERAL PRECUES; SEARCH; DISCRIMINATION; MASKING; INFORMATION; SIMILARITY AB Many studies have found that stimuli can be discriminated more accurately at attended locations than at unattended locations, and such results have typically been taken as evidence for the hypothesis that attention operates by allocating limited perceptual processing resources to attended locations. An alternative proposal, however, is that attention acts to reduce uncertainty about target location, thereby increasing accuracy by decreasing the number of noise sources. To distinguish between these alternatives, we conducted 6 spatial cuing experiments in which target location uncertainty was eliminated. Despite the absence of uncertainty, target discriminations were more accurate at the attended location, consistent with resource allocation models. These cue validity effects were observed under a broad range of conditions, including central and peripheral cuing, but were absent at very short cue-target delay intervals. C1 UNIV CALIF SAN DIEGO,DEPT NEUROSCI,SAN DIEGO,CA 92103. CATHOLIC UNIV AMER,WASHINGTON,DC 20064. USN,RES OFF,ARLINGTON,VA. FU NIMH NIH HHS [MH 25594]; NINDS NIH HHS [NS 17778] NR 57 TC 123 Z9 125 U1 5 U2 20 PU AMER PSYCHOLOGICAL ASSOC PI WASHINGTON PA 750 FIRST ST NE, WASHINGTON, DC 20002-4242 SN 0096-1523 J9 J EXP PSYCHOL HUMAN JI J. Exp. Psychol.-Hum. Percept. Perform. PD JUN PY 1996 VL 22 IS 3 BP 725 EP 737 DI 10.1037/0096-1523.22.3.725 PG 13 WC Psychology; Psychology, Experimental SC Psychology GA UN525 UT WOS:A1996UN52500013 PM 8666960 ER PT J AU Purtell, LP AF Purtell, LP TI Untitled SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Editorial Material RP Purtell, LP (reprint author), OFF NAVAL RES,ARLINGTON,VA 22217, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0098-2202 J9 J FLUID ENG-T ASME JI J. Fluids Eng.-Trans. ASME PD JUN PY 1996 VL 118 IS 2 BP 217 EP 217 DI 10.1115/1.2817365 PG 1 WC Engineering, Mechanical SC Engineering GA UV425 UT WOS:A1996UV42500001 ER PT J AU Johnston, JP Flack, KA AF Johnston, JP Flack, KA TI Review - Advances in three-dimensional turbulent boundary layers with emphasis on the wall-layer regions (data bank contribution) SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Review ID DRIVEN; SWEPT; FLOWS AB Current information concerning three-dimensional turbulent boundary layers is discussed. Several topics are presented including (i) a detailed description of eleven experiments published since 1990. In nine cases cross flows ave controlled by pressure gradients imposed from the freestream, but in two cases the cross flows are wall-shear-driven. The other topics include (ii) art examination of state of the art in measurement techniques; (iii) a look at some issues and ideas in turbulence modeling; and (iv) an introduction to new work on the visualization and description of quasicoherent structures (high/low-speed streaks and turbulent vortices) in three-dimensional turbulent boundary layers. C1 USN ACAD,DEPT MECH ENGN,ANNAPOLIS,MD 21402. RP Johnston, JP (reprint author), STANFORD UNIV,DEPT MECH ENGN,STANFORD,CA 94305, USA. NR 65 TC 50 Z9 51 U1 1 U2 10 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0098-2202 J9 J FLUID ENG-T ASME JI J. Fluids Eng.-Trans. ASME PD JUN PY 1996 VL 118 IS 2 BP 219 EP 232 DI 10.1115/1.2817367 PG 14 WC Engineering, Mechanical SC Engineering GA UV425 UT WOS:A1996UV42500002 ER PT J AU Bandyopadhyay, PR Balasubramanian, R AF Bandyopadhyay, PR Balasubramanian, R TI Structural modeling of the wall effects of Lorentz force SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article C1 SPECTREX INC,GLOUCESTER,VA. RP Bandyopadhyay, PR (reprint author), USN,CTR UNDERSEA WARFARE,NEWPORT,RI 02840, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0098-2202 J9 J FLUID ENG-T ASME JI J. Fluids Eng.-Trans. ASME PD JUN PY 1996 VL 118 IS 2 BP 412 EP 414 DI 10.1115/1.2817395 PG 3 WC Engineering, Mechanical SC Engineering GA UV425 UT WOS:A1996UV42500030 ER PT J AU Kaymaz, Z Luhmann, JG Fedder, JA Lyon, JG Spreiter, JR Stahara, SS AF Kaymaz, Z Luhmann, JG Fedder, JA Lyon, JG Spreiter, JR Stahara, SS TI Evidence for reverse draping of magnetosheath field around the magnetosphere in IMP 8 observations for northward interplanetary magnetic field SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID BOUNDARY-LAYER AB Fedder and Lyon [1995] recently showed the results from a global three-dimensional magnetohydrodynamic (MHD) model of the solar wind interaction with the Earth's magnetic field for northward interplanetary magnetic field (IMF) that exhibited a ''tadpole''-shaped closed magnetosphere, One consequence of this configuration is that the inner magnetosheath or boundary layer fields exhibit reverse draping at the flanks compared to what is expected from the classical gas dynamic picture, This reverse draping, which occurs as a result of near-cusp merging in the MHD model, appears to be present in the statistical field pattern observed on IMP 8 at x approximate to -25-31 R(E). The implication is that boundary layer field configurations for northward IMF produce very different JxB forces on the local boundary layer plasma than would be inferred from classical draping and thus may be responsible for some of the observed IMF dependence of the low-latitude boundary layer properties. C1 UNIV CALIF LOS ANGELES,DEPT ATMOSPHER SCI,LOS ANGELES,CA 90024. USN,RES LAB,DIV PLASMA PHYS,WASHINGTON,DC 20375. DARTMOUTH COLL,DEPT PHYS & ASTRON,HANOVER,NH 03755. STANFORD UNIV,DIV APPL MECH,STANFORD,CA 94305. RMA ASSOCIATES,MT VIEW,CA 94040. NR 12 TC 3 Z9 3 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD JUN 1 PY 1996 VL 101 IS A6 BP 13321 EP 13326 DI 10.1029/96JA00509 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UP353 UT WOS:A1996UP35300024 ER PT J AU Harff, B AF Harff, B TI Death by government - Rummel,RJ SO JOURNAL OF INTERDISCIPLINARY HISTORY LA English DT Book Review RP Harff, B (reprint author), USN ACAD,ANNAPOLIS,MD 21402, USA. NR 3 TC 0 Z9 0 U1 2 U2 3 PU MIT PRESS PI CAMBRIDGE PA 55 HAYWARD ST JOURNALS DEPT, CAMBRIDGE, MA 02142 SN 0022-1953 J9 J INTERDISCIPL HIST JI J. Interdiscip. Hist. PD SUM PY 1996 VL 27 IS 1 BP 117 EP 119 DI 10.2307/206491 PG 3 WC History SC History GA UQ179 UT WOS:A1996UQ17900023 ER PT J AU Sessions, SD AF Sessions, SD TI A comparison of leadership and executive decision making in the military and private sectors SO JOURNAL OF MANAGEMENT INQUIRY LA English DT Editorial Material RP Sessions, SD (reprint author), USN,POSTGRAD SCH,WASHINGTON,DC 20350, USA. NR 1 TC 1 Z9 1 U1 1 U2 1 PU SAGE SCIENCE PRESS PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 SN 1056-4926 J9 J MANAGE INQUIRY JI J. Manage. Inq. PD JUN PY 1996 VL 5 IS 2 BP 122 EP 137 DI 10.1177/105649269652005 PG 16 WC Management SC Business & Economics GA UR189 UT WOS:A1996UR18900005 ER PT J AU Cho, CP Egan, C Krol, WP AF Cho, CP Egan, C Krol, WP TI Application of a high-energy-density permanent magnet material in underwater systems SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE axial field motor; electric motor; FEA modeling; integrated motor/pump; permanent magnet motor AB This paper addresses the application of high-energy-density permanent magnet (PM) technology to (1) the brushless, axial-field PM motor and (2) the integrated electric motor/pump system for underwater applications, Finite-element analysis and lumped parameter magnetic circuit analysis were used to calculate motor parameters and performance characteristics and to conduct tradeoff studies. Compact, efficient, reliable, and quiet underwater systems are attainable with the development of high-energy-density PM material, pow er electronic devices, and power integrated-circuit technology. RP Cho, CP (reprint author), USN,UNDERSEA WARFARE CTR DIV NEWPORT,CODE 8231,BLDG 1302-2,NEWPORT,RI 02841, USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD JUN PY 1996 VL 5 IS 3 BP 299 EP 309 DI 10.1007/BF02649331 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA UN129 UT WOS:A1996UN12900003 ER PT J AU Linnville, SE Elliott, FS Larson, GE AF Linnville, SE Elliott, FS Larson, GE TI Event-related potentials as indices of subclinical neurological differences in HIV patients during rapid decision making SO JOURNAL OF NEUROPSYCHIATRY AND CLINICAL NEUROSCIENCES LA English DT Article ID HUMAN-IMMUNODEFICIENCY-VIRUS; POSITIVE EVOKED-POTENTIALS; INFECTED SUBJECTS; PERFORMANCE; BRAIN; AIDS; IMPAIRMENT; COMPONENT; DISEASE; STIMULI AB The authors examined decision making in HIV patients under slow and rapid information deliveries. Thirteen asymptomatic, HIV-infected (HIV+) subjects with known seroconversion dates and 13 healthy control subjects were instructed to detect the ''oddball'' target tones among nontarget tones during single-channel (slow) and dual-channel (rapid) deliveries. Event-related potentials (ERPs) from midline scalp sites, reaction time, and ''hits'' were recorded. Behaviorally, the two groups performed similarly, and during single-channel delivery they produced Similar ERPs indexing target detection. However, during dual-channel delivery the HIV+ group showed atypical morphology in the region of the P300 cognitive decision-making component compared with the control group. Auditory ERPs elicited by rapid, dichotic stimulus presentations appeared sensitive to subclinical effects of HIV-related neuropathology in individuals who had been HIV-positive for 3 months to 8 years. C1 USN,HLTH RES CTR,COGNIT PERFORMANCE & PSYCHOPHYSIOL DEPT,SAN DIEGO,CA 92152. USN,CTR PERSONNEL RES & DEV,SAN DIEGO,CA 92152. NR 44 TC 5 Z9 5 U1 0 U2 1 PU AMER PSYCHIATRIC ASSOCIATION PI WASHINGTON PA 1400 K ST NW, WASHINGTON, DC 20005 SN 0895-0172 J9 J NEUROPSYCH CLIN N JI J. Neuropsychiatr. Clin. Neurosci. PD SUM PY 1996 VL 8 IS 3 BP 293 EP 304 PG 12 WC Clinical Neurology; Neurosciences; Psychiatry SC Neurosciences & Neurology; Psychiatry GA VB219 UT WOS:A1996VB21900007 PM 8854301 ER PT J AU Mikhail, EM Mansour, NS Mohareb, EW Francies, WM AF Mikhail, EM Mansour, NS Mohareb, EW Francies, WM TI Identification of a misleading trypanosomatid parasite from Gerbillus pyramidum and G-andersoni in a Leishmania major endemic area in north Sinai SO JOURNAL OF PARASITOLOGY LA English DT Article ID CUTANEOUS LEISHMANIASIS AB During an epidemiologic investigation of cutaneous leishmaniasis at a focus in north Sinai, Egypt, between June 1989 and December 1991, 897 desert rodents were trapped and examined to identify reservoir hosts for Leishmania major. Mixed forms of epimastigotes and promastigotes were isolated in Tanabe's medium from 4 Gerbillus pyramidum and 1 Gerbillus andersoni. The 2 forms were later grown and separated a distinct cultures in Schneider's medium. The isoenzyme profile of the gerbils' promastigotes was identified to Leishmania tropica but differed from those of L. major and the gerbils' epimastigotes. The protein pattern by sodium dodecyl sulfate poly acrylamide gel electrophoresis gave no conclusive results. The Hae III restriction endonuclease analysis of kinetoplast DNA of both morphological forms confirmed their similarity and distinguished them from L. tropica and L. major. The gerbils' promastigotes were 30% broader, with a smaller nucleus than those of L. tropica. Following several subcultures, epimastigotes were found to transform to promastigotes. These observations suggest that the 2 forms belong to the genus Trypanosoma. Further studies are in progress to classify this putative Trypanosoma species whose promastigote stages display isoenzyme patterns identical to L. tropica, and which can be misidentified microscopically as Leishmania promastigotes. C1 USN,MED RES UNIT 3,CAIRO,EGYPT. NR 10 TC 2 Z9 3 U1 0 U2 1 PU AMER SOC PARASITOLOGISTS PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 SN 0022-3395 J9 J PARASITOL JI J. Parasitol. PD JUN PY 1996 VL 82 IS 3 BP 400 EP 404 DI 10.2307/3284075 PG 5 WC Parasitology SC Parasitology GA UN548 UT WOS:A1996UN54800004 PM 8636842 ER PT J AU Brook, I Frazier, EH Gher, ME AF Brook, I Frazier, EH Gher, ME TI Microbiology of periapical abscesses and associated maxillary sinusitis SO JOURNAL OF PERIODONTOLOGY LA English DT Article DE periapical abscess, microbiology ID BACTERIOLOGY AB ASPIRATE OF PUS FROM 5 PERIAPICAL ABSCESSES of the upper jaw and their corresponding maxilliary sinusitis were studied for aerobic and anaerobic bacteria. Polymicrobial flora were found in all instances, where the number of isolates varied from 2 to 5. Anaerobes were recovered from all specimens, The predominant isolates were Prevotella sp., Porphyromonas sp., Fusobacterium nucleatum, and Peptostreptococcus sp. Concordance in the microbiological findings between periapical abscess and the maxillary sinus flora was found in all instances. However, certain organisms were only present at one site and not the other. Five beta-lactamase-producing organisms were present in the five specimens. These data confirm the importance of anaerobic bacteria in periapical abscesses and demonstrate their predominance in maxillary sinusitis that is associated with them. C1 USN,MED CTR,DEPT PEDIAT,BETHESDA,MD 20814. USN,MED CTR,DEPT INFECT DIS,BETHESDA,MD 20814. USN,MED CTR,DEPT ORAL SURG,BETHESDA,MD 20814. NR 12 TC 36 Z9 36 U1 0 U2 1 PU AMER ACAD PERIODONTOLOGY PI CHICAGO PA 737 NORTH MICHIGAN AVENUE, SUITE 800, CHICAGO, IL 60611-2690 SN 0022-3492 J9 J PERIODONTOL JI J. Periodont. PD JUN PY 1996 VL 67 IS 6 BP 608 EP 610 PG 3 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA UR846 UT WOS:A1996UR84600009 PM 8794972 ER PT J AU Whitten, RC AF Whitten, RC TI Tailhook 91 .2. Events at the Annual Tailhook Symposium - Assist-Inspect-Gen-Invest, Assist-Inspect-Gen-Dept-Inquir SO JOURNAL OF POLITICAL & MILITARY SOCIOLOGY LA English DT Book Review RP Whitten, RC (reprint author), NASA,USN RESERVE,WASHINGTON,DC, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU JOURNAL POLITICAL MILITARY SOCIOLOGY PI DE KALB PA DEPT SOCIOLOGY, NORTHERN ILLINOIS UNIV, DE KALB, IL 60115-2854 SN 0047-2697 J9 J POLIT MIL SOCIOL JI J. Polit. Mil. Soc. PD SUM PY 1996 VL 24 IS 1 BP 145 EP 149 PG 5 WC Political Science; Sociology SC Government & Law; Sociology GA VA946 UT WOS:A1996VA94600010 ER PT J AU Chan, LY Mostovych, AN Kearney, KJ AF Chan, LY Mostovych, AN Kearney, KJ TI Stark broadening measurements of Al(III) doublet lines in dense and optically-thin laser plasmas SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID SPECTRAL-LINES; ALUMINUM; WIDTHS AB Line emission profiles of doubly-ionized aluminium doublets at 360 and 570 nm are measured in a laser-produced plasma (n(e) = 0.2-1.6 x 10(19) cm(-3), kT = 3-8 eV) to study line broadening in dense and cold plasmas. The density and temperature of the plasma are measured independent of spectral measurements using interferometry, absorption and absolute emission diagnostics. Experimental line widths are obtained by least-squares fits to composite Lorentzian curves corresponding to both uniform slab approximation and integration over plasma density profiles. Comparisons with semi-empirical line width calculations agree to within experimental error of 20%. Copyright (C) 1996 Published by Elsevier Science Ltd RP Chan, LY (reprint author), USN,RES LAB,DIV PLASMA PHYS,LASER PLASMA BRANCH,WASHINGTON,DC 20375, USA. NR 16 TC 8 Z9 8 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD JUN PY 1996 VL 55 IS 6 BP 815 EP 821 DI 10.1016/0022-4073(95)00188-3 PG 7 WC Optics; Spectroscopy SC Optics; Spectroscopy GA UT936 UT WOS:A1996UT93600013 ER PT J AU Kresin, VZ Wolf, SA Ovchinnikov, YN AF Kresin, VZ Wolf, SA Ovchinnikov, YN TI Upper limit of T-c for the copper oxides SO JOURNAL OF SUPERCONDUCTIVITY LA English DT Article DE cuprates; upper limit of T-c ID SINGLE-CRYSTAL; SUPERCONDUCTIVITY; FIELD; STATE AB The value of the critical temperature of the cuprates correlates with the doping level and is affected by the interplay of two competing factors: (1) the increase in carrier concentration, and (2) the pair-breaking effect of magnetic impurities. An analysis of the temperature dependence of the critical field leads to the conclusion that magnetic impurities are present even in a sample with the maximum observed value of T-c. A new parameter, "intrinsic" T-c (T-c intr), which is its value in the absence of magnetic impurities, is introduced. The maximum value of T-c intr, which corresponds to the maximum doping level, appears to be similar for different cuprates and to be equal to 160-170 K. This is the upper limit of T-c in the cuprates. C1 USN, RES LAB, WASHINGTON, DC 20375 USA. LD LANDAU THEORET PHYS INST, MOSCOW 11733V, RUSSIA. RP Kresin, VZ (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RI Wolf, Stuart/A-7513-2009 NR 32 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0896-1107 J9 J SUPERCOND JI J. Supercond. PD JUN PY 1996 VL 9 IS 3 BP 329 EP 333 DI 10.1007/BF00727557 PG 5 WC Physics, Applied; Physics, Condensed Matter SC Physics GA UW494 UT WOS:A1996UW49400013 ER PT J AU Feuillade, C AF Feuillade, C TI The attenuation and dispersion of sound in water containing multiply interacting air bubbles SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID ACOUSTIC SCATTERING; OCEAN; SURFACE; PROPAGATION; CLOUDS; MODEL; SIZE AB The classic theory of linear acoustic propagation in bubbly water inaccurately represents the physical behavior of dense populations of resonating bubbles. It assumes the bubbles always oscillate independently, while they may actually be strongly coupled by acoustic radiation, especially when uniformly sized. Sound propagation can be properly understood only in terms of the collective action of the medium, which is dominated by the ''symmetric'' normal mode. In this work, the propagational characteristics of bubbly water are determined by averaging the ensemble behavior of the symmetric mode over distributions of bubble radii and locations. The method includes all orders of multiple scattering, and incorporates ''shielding'' effects in the medium. New theoretical expressions for the phase speed and attenuation are obtained, and compared to experimental data by integrating multiple scattering effects over a ''region of collective interaction'' around each bubble. For uniform bubbles and volume fractions beta greater than or equal to 0.22%, multiple scattering strongly influences propagation. When beta < 0.22%, the effects apparently diminish sharply. For nonuniform bubbles and beta approximate to 0.02%, multiple scattering effects are not indicated. These results imply that the classic theory should provide an adequate description of the acoustic properties of bubble plums and clouds typically encountered in the ocean. RP Feuillade, C (reprint author), USN,RES LAB,BAY ST LOUIS,MS 39529, USA. NR 36 TC 41 Z9 42 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUN PY 1996 VL 99 IS 6 BP 3412 EP 3430 DI 10.1121/1.415216 PG 19 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UQ669 UT WOS:A1996UQ66900014 ER PT J AU George, J AF George, J TI Physical mechanisms to explain the observed features of ambient noise in shallow water SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID STATISTICS AB Possible physical mechanisms for two features of ambient noise observed in shallow water in the Pacific are explored. These features are (a) non-Gaussian distribution of the probability density function, and (b) the fact that probability density function plots whose X scales are normalized by the standard deviation of the power decibel levels of each hydrophone are independent of depth. The results of the analysis show that variation in multipath interference of distant shipping noise is an unlikely cause of the observed features. Predictions based on source depth variations caused by wave action when a dominant noise source (such as the hull of a large ship) is located close to the surface agree with the observed features. A parametric match to the experimental probability density functions has been found with the use of non-Gaussian random noise. Future studies are recommended to explore the distributions in other oceanic regions and for other frequency bands, and to identify the underlying ambient noise mechanisms. (C) 1996 Acoustical Society of America. RP George, J (reprint author), USN,RES LAB,OCEAN ACOUST BRANCH,BAY ST LOUIS,MS 39529, USA. NR 21 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUN PY 1996 VL 99 IS 6 BP 3439 EP 3444 DI 10.1121/1.414990 PG 6 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UQ669 UT WOS:A1996UQ66900016 ER PT J AU Houston, BH Marcus, MH Bucaro, JA Williams, EG Photiadis, DM AF Houston, BH Marcus, MH Bucaro, JA Williams, EG Photiadis, DM TI The structural acoustics and active control of interior noise in a ribbed cylindrical shell SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID CYLINDER AB Numerical studies are carried out regarding the structural acoustics of a ribbed aluminum cylindrical shell structure intended to represent the essential structural features of a small aircraft fuselage. Calculations are made to determine both the wall normal displacements and the interior acoustic pressures for the case in which the shell wall is forced dynamically at a point. The structural responses are further decomposed into their frequency-wave-number components. Through a series of comparisons between those responses for an infinite shell, the ribbed vacuum-filled shell, and the ribbed air-filled shell, the relevant structural acoustic mechanisms are interpreted. The frequencies at which interior acoustic ''resonances'' are observed are connected to specific mechanisms, including cavity responses driven by structural modes, cavity modes forcing the structure, and mixed structure/air-cavity modes. Numerically based active control experiments are carried out using end actuation, and the relative performance of this control ''system'' is compared when operating on the various mode types. RP Houston, BH (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 16 TC 4 Z9 4 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUN PY 1996 VL 99 IS 6 BP 3497 EP 3512 DI 10.1121/1.414949 PG 16 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UQ669 UT WOS:A1996UQ66900023 ER PT J AU Kaiser, AR Cain, CA Hwang, EY Fowlkes, JB Jeffers, RJ AF Kaiser, AR Cain, CA Hwang, EY Fowlkes, JB Jeffers, RJ TI A cost effective degassing system for use in ultrasonic measurements: The multiple pinhole degassing system SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB The multiple pinhole degassing (MPD) system discussed below is an inexpensive method for lowering the dissolved oxygen concentration of water to levels acceptable for ultrasonic research. Several methods of degassing water for ultrasonic measurement and operation are available. However, many of these degassing systems are expensive to purchase and are complex, sometimes requiring considerable maintenance. The system described here is ideal for degassing large volumes of water in circulating applications. It degasses 80 liters of water to below 4 ppm O-2 in 5 h and to about 2 ppm O-2 in 24 h. It also enables easy collection of removed gases. At the time of this writing the system requires a standard pump and about ten dollars of hardware supplies. C1 UNIV MICHIGAN,MED CTR,DEPT RADIOL,BASIC RADIOL SCI DIV,ANN ARBOR,MI 48109. USN,UNDERSEA WARFARE CTR,NEWPORT,RI 02841. RP Kaiser, AR (reprint author), UNIV MICHIGAN,DEPT ELECT ENGN & COMP SCI,BIOMED ULTRASON LAB,ANN ARBOR,MI 48109, USA. NR 4 TC 27 Z9 27 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JUN PY 1996 VL 99 IS 6 BP 3857 EP 3859 DI 10.1121/1.415211 PG 3 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UQ669 UT WOS:A1996UQ66900062 ER PT J AU Koh, HK Norton, LA Geller, AC Sun, T Rigel, DS Miller, DR Sikes, RG Vigeland, K Bachenberg, EU Menon, PA Billon, SF Goldberg, G Scarborough, DA Ramsdell, WM Muscarella, VA Lew, RA AF Koh, HK Norton, LA Geller, AC Sun, T Rigel, DS Miller, DR Sikes, RG Vigeland, K Bachenberg, EU Menon, PA Billon, SF Goldberg, G Scarborough, DA Ramsdell, WM Muscarella, VA Lew, RA TI Evaluation of the American Academy of Dermatology's national skin cancer early detection and screening program SO JOURNAL OF THE AMERICAN ACADEMY OF DERMATOLOGY LA English DT Article ID MALIGNANT-MELANOMA AB Background: Increasing incidence and mortality rates from cutaneous melanoma are a major public health concern. As part of a national effort to enhance early detection of melanoma/skin cancer, the American Academy of Dermatology (AAD) has sponsored an annual education and early detection program that couples provision of skin cancer information to the general public with almost 750,000 free skin cancer examinations (1985-1994). Objective: To begin to evaluate the impact of this effort, we determined the final pathology diagnosis of persons attending the 1992-1994 programs who had a suspected melanoma at the time of examination. Methods: We directly contacted all such persons by telephone or mail and received pathology reports from those who had a subsequent biopsy. Results: We contacted 96% of the 4458 persons with such lesions among the 282,555 screenings in the 1992-1994 programs. We obtained a final diagnosis for 72%, and the positive predictive value for melanoma was 17%. Three hundred seventy-one melanomas were found in 364 persons. More than 98% had localized disease. More than 90% of the confirmed melanomas with known histology were in situ or ''thin'' lesions (less than or equal to 1.50 mm thick). The median thickness of all melanomas was 0.30 mm. The 8.3% of AAD cases with advanced melanoma (metastatic disease, regional disease, or lesions greater than or equal to 1.51 mm) is a lower proportion than that reported by the 1990 Surveillance, Epidemiology and End Result Registry. The rate of thickest lesions (greater than or equal to 4 mm) and late-stage melanomas among all participants was 2.83 per 100,000 population. Of persons with a confirmed melanoma, 39% indicated (before their examination) that without the free program, they would not have considered having a physician examine their skin. Conclusion: The 1992-1994 free AAD programs disseminated broad skin cancer educational messages, enabled thousands to obtain a free expert skin cancer examination, and found mostly thin, localized stage 1 melanomas (usually associated with a high projected 5-year survival rate). Because biases impose possible limitations, future studies with long-term follow-up and formal control groups should determine the impact of early detection programs on melanoma mortality. C1 BOSTON UNIV,SCH MED,DEPT DERMATOL,BOSTON,MA 02118. BOSTON UNIV,SCH MED,DEPT MED,BOSTON,MA 02118. BOSTON UNIV,SCH MED,CANC PREVENT & CONTROL CTR,BOSTON,MA 02118. BOSTON UNIV,SCH PUBL HLTH,BOSTON,MA. NYU,DEPT DERMATOL,NEW ROCHELLE,NY. OREGON HLTH SERV UNIT,PORTLAND,OR. OHIO STATE UNIV HOSP,DIV DERMATOL,COLUMBUS,OH 43210. USN,MED CTR,DEPT DERMATOL,BETHESDA,MD 20814. UNIV ARIZONA,HLTH SCI CTR,DEPT DERMATOL & PEDIAT,TUCSON,AZ 85724. AMER ACAD DERMATOL,DEPT COMMUN,SCHAUMBURG,IL. UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. NR 22 TC 99 Z9 99 U1 0 U2 4 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 SN 0190-9622 J9 J AM ACAD DERMATOL JI J. Am. Acad. Dermatol. PD JUN PY 1996 VL 34 IS 6 BP 971 EP 978 DI 10.1016/S0190-9622(96)90274-1 PG 8 WC Dermatology SC Dermatology GA UP210 UT WOS:A1996UP21000004 PM 8647990 ER PT J AU Liberman, MA Phillips, EH Carroll, BJ Fallas, MJ Rosenthal, R Hiatt, J AF Liberman, MA Phillips, EH Carroll, BJ Fallas, MJ Rosenthal, R Hiatt, J TI Cost-effective management of complicated choledocholithiasis: Laparoscopic transcystic duct exploration or endoscopic sphincterotomy SO JOURNAL OF THE AMERICAN COLLEGE OF SURGEONS LA English DT Article ID COMMON BILE-DUCT; RETROGRADE CHOLANGIOPANCREATOGRAPHY; STONE REMOVAL; CHOLECYSTECTOMY; CHOLANGIOGRAPHY; PANCREATITIS; SURGERY; ERCP AB BACKGROUND: In the United States of America, approximately 700,000 patients undergo laparoscopic cholecystectomy (LC) each year and at least 10 percent of these patients will have common bile duct stones (CBDS). The purpose of this study was to evaluate patients with choledocholithiasis and compare the economic and clinical results obtained by LC with endoscopic sphincterotomy (ES) with those of LC with laparoscopic transcystic common bile duct exploration (LTCBDE). STUDY DESIGN: From June 1991 to September 1994 patients undergoing LC plus LTCBDE and those undergoing LC plus ES at a single institution were compared where cost data were available. Of the 76 patients with choledocholithiasis, 59 patients underwent LC plus LTCBDE (group 1) and 17 patients underwent LC plus ES (group 2). A subset of group 1 patients undergoing urgent LC plus LTCBDE (group 3) for cholecystitis, cholangitis, or pancreatitis plus laparoscopy were examined separately. RESULTS: Laparoscopic cholecystectomy plus LTCBDE, whether including all-comers (group I) or just urgent cases (group 3), was associated with a significantly decreased length of hospital stay (6.1 and 6.9 days, respectively, compared with group 2, 12.4 days) (p<0.001), The morbidity of patients in group 1 was also markedly lower than for patients in group 2; 12 percent compared with 41 percent, respectively. Patients in group 1 had a significantly decreased cost of hospitalization ($13,151), when compared with patients in group 2 ($18,712) (p=0.05). This difference is even more pronounced when professional fee reimbursement is considered. The cost of treatment for patients in group 1 was $14,732 compared with $21,125 for patients in group 2 (p<0.05). The total hospital cost for patients in group 3 was only $13,564 compared with $18,712 for patients in group 2. When professional reimbursement was considered, the cost was $15,150 for patients in group 3 compared with $21,125 for patients in group 2. CONCLUSIONS: Patients undergoing LC plus LTCBDE for CBDS, whether urgently or electively, have markedly decreased morbidity rates, length of hospital stay, and costs when compared with patients undergoing LC plus ES. C1 CEDARS SINAI MED CTR,LOS ANGELES,CA 90048. RP Liberman, MA (reprint author), USN,MED CTR,DEPT SURG,SAN DIEGO,CA 92134, USA. RI wong, jun/M-7851-2013 NR 28 TC 69 Z9 74 U1 0 U2 0 PU AMER COLL SURGEONS PI CHICAGO PA 54 EAST ERIE ST, CHICAGO, IL 60611 SN 1072-7515 J9 J AM COLL SURGEONS JI J. Am. Coll. Surg. PD JUN PY 1996 VL 182 IS 6 BP 488 EP 494 PG 7 WC Surgery SC Surgery GA UP380 UT WOS:A1996UP38000004 PM 8646348 ER PT J AU Daily, PO Freeman, RK Dembitsky, WP Adamson, RM MorenoCabral, RJ Marcus, S Lamphere, JA AF Daily, PO Freeman, RK Dembitsky, WP Adamson, RM MorenoCabral, RJ Marcus, S Lamphere, JA TI Cost reduction by combined carotid endarterectomy and coronary artery bypass grafting SO JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY LA English DT Article; Proceedings Paper CT 21st Annual Meeting of the Western-Thoracic-Surgical-Association CY JUN 21-24, 1995 CL COEUR DALENE, ID SP W Thorac Surg Assoc ID SIMULTANEOUS MYOCARDIAL REVASCULARIZATION; CONCOMITANT OCCLUSIVE DISEASE; CARDIOPULMONARY BYPASS; CEREBROVASCULAR-DISEASE; SURGICAL-MANAGEMENT; CARDIAC-SURGERY; STENOSIS; OPERATIONS; STROKE; SAFETY AB A significant cost reduction is likely if patients who require coronary artery bypass grafting with significant carotid stenosis have simultaneous carotid endarterectomy and bypass grafting, provided risk is not increased. To investigate this issue, we retrospectively identified cases from February 1977 to May 1994 with first-time isolated carotid endarterectomy, coronary bypass, or combined procedures. In the isolated carotid endarterectomy population, median age was 69 years and 58% (85/146) were male, as compared with 68 years and 68% (68/100) male in the combined group; median age of the coronary bypass cohort was 65 years and 76% (381/500) male. A significantly higher percentage of patients in the coronary bypass versus combined group were in New York Heart Association functional class IV. In the combined group there was a significantly higher incidence of older age, diabetes, hypertension, hyperlipidemia, renal failure, and congestive heart failure. There was no difference among the three groups with respect to hospital mortality (0%, 3.4%, and 4.0%, respectively) and permanent stroke (0.7%, 1.2%, and 0%, respectively). Hospital costs were $4,896, $10,959 and $11,089, respectively, with a savings of $4,766 (30%), and Medicare hospital reimbursement was $8,575, $23,071, and $23,071, respectively, with a savings of $10,077 (25.3%). Thus, in appropriate patients, a combined procedure is cost effective, eliminating a second surgical procedure and the cost of the postoperative stay (3.7 +/- 2.4 days) associated with isolated carotid endarterectomy. Risk of permanent stroke or death is not increased. C1 SHARP MEM HOSP & REHABIL CTR,SAN DIEGO,CA 90034. USN,REG MED CTR,SAN DIEGO,CA 92152. NR 56 TC 63 Z9 67 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 SN 0022-5223 J9 J THORAC CARDIOV SUR JI J. Thorac. Cardiovasc. Surg. PD JUN PY 1996 VL 111 IS 6 BP 1185 EP 1192 DI 10.1016/S0022-5223(96)70220-9 PG 8 WC Cardiac & Cardiovascular Systems; Respiratory System; Surgery SC Cardiovascular System & Cardiology; Respiratory System; Surgery GA UQ383 UT WOS:A1996UQ38300013 PM 8642819 ER PT J AU Zimmerman, RC Alberte, RS AF Zimmerman, RC Alberte, RS TI Effect of light/dark transition on carbon translocation in eelgrass Zostera marina seedlings SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE seagrass; anoxia; translocation; light; photosynthesis; carbon transport ID SEAGRASS PHOTOSYNTHESIS; DIURNAL CHANGES; PHOSPHORUS; GROWTH; DEPTH; METABOLISM; ENZYMES; ROOTS AB Carbon translocation in the marine macrophyte Zostera marina L. (eelgrass) was investigated to elucidate the impact of light/dark transitions on sucrose partitioning between roots and shoots. After exposure of leaves to C-14-bicarbonate, the level of C-14-labelled photoassimilates increased monotonically in both leaves and fully aerobic roots of plants maintained in the light. Accumulation of C-14 in roots and leaves ceased abruptly when plants were transferred to darkness that induced root anaerobiosis even though C-14 levels remained high in the dark-exposed leaves. Thus, translocation of C-14 photoassimilates from shoots to roots was inhibited when roots became anoxic. Anoxia induced by light limitation of photosynthesis, whether due to day/night transitions or periods of extreme light attenuation in the water column, can have an impact on carbon availability in subterranean tissues of eelgrass. As a consequence, light availability is likely to control the productivity and distribution of eelgrass in highly variable and light-limited coastal environments through its effects on carbon partitioning between shoots and roots, in addition to whole-plant carbon balance. C1 UNIV CALIF LOS ANGELES, DEPT BIOL, LOS ANGELES, CA 90024 USA. OFF NAVAL RES, BIOL SCI & TECHNOL PROGRAM, ARLINGTON, VA 22217 USA. NR 31 TC 45 Z9 45 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. PD JUN PY 1996 VL 136 IS 1-3 BP 305 EP 309 DI 10.3354/meps136305 PG 5 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA UU026 UT WOS:A1996UU02600028 ER PT J AU Steinert, SA AF Steinert, SA TI Contribution of apoptosis to observed DNA damage in mussel cells SO MARINE ENVIRONMENTAL RESEARCH LA English DT Article; Proceedings Paper CT 8th International Symposium on Pollutant Responses in Marine Organisms (PRIMO 9) CY APR 02-05, 1995 CL PACIFIC GROVE, CA SP Univ Calif Davis, US EPA, Ctr Ecol Hlth Res, Univ Calif Davis, Superfund Basic Sci Res Program, NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, State Calif Fish & Gam Off Oil Spill Prevent & Response, Vet Serv, US Natl Inst Environm Hlth Sci, Monterey Bay Aquarium, Calif Sea Grant Program AB The comet assay employs the expression of DNA strand breaks by alkaline treatment to measure DNA damage. In contrast to other similar alkaline treatment assays the comet assay incorporates the microscopic examination of damage to individual cell nuclei. Because individual nuclei are examined, features unique to apoptotic cells can be identified. Apoptosis, programmed cell death, is characteristically an orderly sequence of events that ultimately leads to the complete disassembly of a cell. One consequence of apoptosis is the induction of endogenous nucleases which results in the fragmentation of DNA. Apoptosis can be triggered by a variety of stimuli, giving the misleading impression of genotoxic damage if this cytotoxic mechanism of DNA fragmentation is not taken into consideration. In this study mussel cells were exposed to a variety of toxicants and the cytotoxic (apoptotic) contribution to observed DNA damage was determined. A number of stressors induced apoptosis quite rapidly, within hours of exposure. The comet assay detected apoptosis and under certain circumstances apoptosis was found to be the major contributor to observed DNA damage. Copyright (C) 1996 Elsevier Science Ltd. C1 USN, COMMAND CONTROL & OCEAN SURVEILLANCE CTR, OCEAN SCI LAB, SAN DIEGO, CA 92152 USA. RP Steinert, SA (reprint author), COMP SCI CORP, MARINE SCI DIV, SAN DIEGO, CA 92110 USA. NR 7 TC 68 Z9 73 U1 0 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0141-1136 J9 MAR ENVIRON RES JI Mar. Environ. Res. PD JUN-OCT PY 1996 VL 42 IS 1-4 BP 253 EP 259 DI 10.1016/0141-1136(95)00056-9 PG 7 WC Environmental Sciences; Marine & Freshwater Biology; Toxicology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Toxicology GA UU369 UT WOS:A1996UU36900042 ER PT J AU Kahn, M Krause, D Chase, M AF Kahn, M Krause, D Chase, M TI Flaw detection in d(33) mode multilayer ceramic actuators using impedance-frequency scans SO MATERIALS EVALUATION LA English DT Article DE acoustics; ceramic material; destructive parts analysis; flaw detection; high frequency impedance; nondestructive testing; piezoelectric resonances; ultrasonic testing AB A method to detect linear flaws in piezoelectric actuators is demonstrated: piezoelectrically induced vibrations are excited in the actuator at a large number of closely spaced frequencies. They propagate at 4,240 m/s (13,900 ft/s) in the ceramic and are 22 percent slower at 90 degrees to the 150 electrode layers in the actuators tested here. At frequencies of mechanical resonance there are steep impedance peaks and an impedance peak pattern versus frequency is generated that is characteristic of a particular actuator configuration. It is shown that when the amplitudes of such peaks are depressed significantly, i.e. by 50 percent or more, or when there are peaks >2 kHz removed from ''normal'' peak locations, significant internal flaws are present. A high detection sensitivity for small peaks is obtained from a difference plot, in which the response at each test frequency is subtracted from that at its neighboring test frequency. A ''kaleidograph'' plotting routine that uses the output of an HP4192A impedance analyzer was found to give a lower noise level than when a linear plotter is teamed directly with an HP4194A impedance analyzer. Also, samples that exhibited on conventional electrical tests above 100 kHz unusually high dissipation factors and abnormal d(33) or 300 V displacement values, showed evidence of internal flaws. Actuators made from electrostrictive PMN also showed extraneous peaks when internal flaws are present. In both types of devices there are acoustic anomalies in all samples that had linear flaws and visa versa. C1 POTOMAC RES INT,FAIRFAX,VA 22030. RP Kahn, M (reprint author), USN,RES LAB,CODE 6384,WASHINGTON,DC 20375, USA. NR 8 TC 4 Z9 5 U1 0 U2 0 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD JUN PY 1996 VL 54 IS 6 BP 749 EP 754 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA UP804 UT WOS:A1996UP80400005 ER PT J AU Enomoto, M Lee, JK Rath, BB Reynolds, WT Rigsbee, JM Russell, KC AF Enomoto, M Lee, JK Rath, BB Reynolds, WT Rigsbee, JM Russell, KC TI Symposium on atomistic mechanisms of nucleation and growth in solids - Foreword SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Editorial Material C1 USN,RES LAB,WASHINGTON,DC 20375. MICHIGAN TECHNOL UNIV,HOUGHTON,MI 49931. VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. UNIV ALABAMA,BIRMINGHAM,AL. MIT,CAMBRIDGE,MA 02139. RP Enomoto, M (reprint author), IBARAKI UNIV,HITACHI,IBARAKI 316,JAPAN. NR 0 TC 2 Z9 2 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUN PY 1996 VL 27 IS 6 BP 1427 EP 1427 DI 10.1007/BF02649802 PG 1 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA UR669 UT WOS:A1996UR66900002 ER PT J AU Vandermeer, RA Rath, BB AF Vandermeer, RA Rath, BB TI Characterization of a massive transformation by microstructural analysis SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Atomistic Mechanisms of Nucleation and Growth in Solids, at TMS/ASM Materials Week CY OCT 03-05, 1994 CL ROSEMONT, IL SP TMS, ASM ID NUCLEATION; ALLOYS AB Quantitative metallography was employed to investigate experimentally the nucleation behavior and growth rates in a quenched Ag + 50 at. pct Cd alloy undergoing an isothermal massive transformation at 373 K (100 degrees C). The experimental characterization of the massively transforming microstructure as a function of time was accomplished by the stereological measurement of the microstructural variables, V-nu, the volume fraction transformed, S-nu, the parent/daughter interfacial area density, and lambda(max), the largest intercept-free nodule length of the newly forming daughter phase. These data were compared to statistically derived geometrical models of the microstructure formulated on various nucleation and growth premises and expressed in terms of these same variables, A model was found which matched the data in all respects, and this allowed certain nucleation characteristics, the interface migration rates, and the nodule shapes of the daughter phase to be deduced. RP Vandermeer, RA (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 19 TC 1 Z9 1 U1 1 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUN PY 1996 VL 27 IS 6 BP 1513 EP 1518 DI 10.1007/BF02649811 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA UR669 UT WOS:A1996UR66900011 ER PT J AU Spanos, G Hall, MG AF Spanos, G Hall, MG TI The formation mechanism(s), morphology, and crystallography of ferrite sideplates SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Atomistic Mechanisms of Nucleation and Growth in Solids, at TMS/ASM Materials Week CY OCT 03-05, 1994 CL ROSEMONT, IL SP TMS, ASM ID LEDGED INTERPHASE BOUNDARIES; 2-PHASE STAINLESS-STEEL; GROWTH-KINETICS; PRECIPITATION; ALLOY; TRAIN; STEPS AB The formation mechanism(s), morphology, and crystallography of secondary ferrite sideplates were investigated with transmission electron microscopy (TEM), scanning electron microscopy (SEM), electron backscatter pattern (EBSP) analysis, and optical microscopy in a high-purity Fe-0.12 wt pet C-3.3 wt pet Ni alloy isothermally transformed at temperatures of 550 degrees C, 600 degrees C, 650 degrees C, and 675 degrees C. The results indicate that two different mechanisms contribute to the formation of these sideplates at austenite grain boundaries. On the first mechanism, primary sideplates form initially, followed by rapid lateral impingement along their bases, resulting in a region along the grain boundary which very early in the growth process resembles an allotriomorphic film. On the second mechanism, sympathetic nucleation of ferrite sideplates occurs atop pre-existing ferrite allotriomorphs, resulting in ferrite:ferrite grain boundaries and significant crystallographic misorientations between the sideplates and the allotriomorphs with which they are associated. These results indicate that ''secondary sideplates'' and the allotriomorphs from which they evolve are not composed of monolithic single crystals formed by a morphological instability mechanism but are instead composed of multiple crystals formed by individual nucleation events. Previous investigations in Ti-Cr alloys and a high chromium stainless steel suggest that the findings presented here may be applicable to a number of other alloy systems as well. C1 UNIV BIRMINGHAM,SCH MET & MAT,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND. RP Spanos, G (reprint author), USN,RES LAB,PHYS MET BRANCH,WASHINGTON,DC 20375, USA. NR 43 TC 31 Z9 31 U1 0 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUN PY 1996 VL 27 IS 6 BP 1519 EP 1534 DI 10.1007/BF02649812 PG 16 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA UR669 UT WOS:A1996UR66900012 ER PT J AU Menon, ESK Subramanian, PR Dimiduk, DM AF Menon, ESK Subramanian, PR Dimiduk, DM TI Phase transformations in Nb-Al-Ti alloys SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Atomistic Mechanisms of Nucleation and Growth in Solids, at TMS/ASM Materials Week CY OCT 03-05, 1994 CL ROSEMONT, IL SP TMS, ASM ID RIBBONS; SYSTEM AB Phase relationships as well as morphological and crystallographic features in Nb-rich Nb-Al and Nb-Al-Ti alloys have been investigated. The phase boundaries involving the bcc and Nb3Al (Al5 structure) were experimentally determined and several isothermal sections of the Nb-rich corner of the Nb-Al-Ti phase diagram established. The present findings show that (a) the solubility of Al in Nb is considerably less than that reported previously, (b) the high-temperature bcc phase undergoes an ordering transformation to the B2 structure, and (c) the omega phase also forms in these alloys. The sequence of decomposition of the high-temperature bcc phase during isothermal decomposition in the bcc + Nb3Al phase field has been systematically studied in these alloys. A wide variety of morphological features were found to be associated with the Nb3Al precipitates that formed in the bcc/B2 matrix during isothermal heat treatments. The lengthening kinetics of the plate-shaped Nb3Al precipitates were also studied. C1 UNIVERSAL ENERGY SYST INC,DAYTON,OH 45432. USAF,WRIGHT LAB,MLLM,MAT DIRECTORATE,WRIGHT PATTERSON AFB,OH 45433. RP Menon, ESK (reprint author), USN,POSTGRAD SCH,DEPT MECH ENGN,MAT SCI SECT,MONTEREY,CA 93943, USA. NR 31 TC 40 Z9 42 U1 0 U2 3 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUN PY 1996 VL 27 IS 6 BP 1647 EP 1659 DI 10.1007/BF02649822 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA UR669 UT WOS:A1996UR66900022 ER PT J AU Hoyt, RE Herip, DS AF Hoyt, RE Herip, DS TI Severe systemic reactions attributed to the acetone-inactivated parenteral typhoid vaccine SO MILITARY MEDICINE LA English DT Article ID VI-CAPSULAR POLYSACCHARIDE; SALMONELLA-TYPHI; UNITED-STATES; FIELD TRIAL; MANIFESTATIONS; FEVER AB Typhoid vaccine is recommended for people traveling to areas where they may be exposed to contaminated food and/or mater. Two different parenteral forms of the vaccine have been utilized. We report five active duty patients with severe systemic reactions to the acetone-inactivated form of typhoid vaccine. The patients presented with very similar physical exam findings and laboratory abnormalities. Alternative typhoid vaccines that are less reactogenic are now available for use. RP Hoyt, RE (reprint author), USN HOSP,DEPT INTERNAL MED,6000 W HIGHWAY 98,PENSACOLA,FL 32512, USA. NR 18 TC 2 Z9 2 U1 0 U2 0 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 SN 0026-4075 J9 MIL MED JI Milit. Med. PD JUN PY 1996 VL 161 IS 6 BP 339 EP 341 PG 3 WC Medicine, General & Internal SC General & Internal Medicine GA UP825 UT WOS:A1996UP82500012 PM 8700328 ER PT J AU Auclair, PL Ellis, GL AF Auclair, PL Ellis, GL TI Atypical features in salivary gland mixed tumors: Their relationship to malignant transformation SO MODERN PATHOLOGY LA English DT Article DE carcinoma ex mixed tumor; malignant transformation; mixed tumor; pleomorphic adenoma; salivary gland neoplasms ID PAROTID-GLAND; PLEOMORPHIC ADENOMA; MITOTIC RATE; CARCINOMAS; BENIGN AB Although criteria far distinction between the benign and malignant elements Ln carcinoma ex mixed tumor have been adequately described, there have not been any attempts to identify clinical or histologic features in benign mixed tumors that indicate increased risk of malignant change. I;or this reason, 65 mixed tumors of the major and minor salivary glands that exhibited atypical histologic features were examined in an attempt to analyze which, if any, of these features might indicate a greater likelihood of malignant transformation, The atypical features evaluated were hypercellularity, capsule violation, hyalinization,necrosis, and cellular anaplasia The mitotic rate was also analyzed. The age of the patient, and the site, size, and prediagnostic duration of the tumor were recorded and, together with the histologic findings, were correlated with follow-up information. Nine (13.8%) of the 65 tumors underwent malignant transformation. Five of these patients died of the tumor, two others had distant metastases and were alive with the disease, and two were free of disease. Benign mixed tumors lat showed prominent zones of hyalinization or at least moderate mitotic activity were more likely to develop carcinoma than those that did not. chi(2) analysis indicated that only hyalinization was significant (P < 0.05), but, with Fisher's exact test (two-tailed), this and;all of the other features evaluated revealed a P value greater than 0.05. The other atypical features faded to correlate with malignant change. Clinical findings at the initial diagnosis that indicated a greater likelihood of malignant transformation were occurrence in the submandibular gland, older patient age, and large tumor size. C1 ARMED FORCES INST PATHOL,DEPT ORAL PATHOL,WASHINGTON,DC 20306. ARMED FORCES INST PATHOL,VET AFFAIRS SPECIAL REFERENCE LAB PATHOL,WASHINGTON,DC 20306. RP Auclair, PL (reprint author), USN,NATL NAVAL DENT CTR,SCH DENT,DEPT ORAL PATHOL,8901 WISCONSIN AVE,BETHESDA,MD 20889, USA. NR 21 TC 55 Z9 60 U1 0 U2 1 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0893-3952 J9 MODERN PATHOL JI Mod. Pathol. PD JUN PY 1996 VL 9 IS 6 BP 652 EP 657 PG 6 WC Pathology SC Pathology GA UQ507 UT WOS:A1996UQ50700010 PM 8782203 ER PT J AU Reynolds, C Gelaro, R Murphree, T AF Reynolds, C Gelaro, R Murphree, T TI Observed and simulated northern hemisphere intraseasonal circulation anomalies and the influence of model bias SO MONTHLY WEATHER REVIEW LA English DT Article ID LOW-FREQUENCY VARIABILITY; TROPICAL CONVECTION; GEOPOTENTIAL HEIGHT; FORECAST MODEL; TIME SCALES; WINTER; PROPAGATION; PATTERNS; OSCILLATIONS; TELECONNECTIONS AB The ability of an atmospheric general circulation model to simulate the observed primary modes of intraseasonal variability in the Northern Hemisphere upper-tropospheric winds during boreal winter is examined. The model used is the Navy Operational Global Atmospheric prediction System. The authors examine differences between the observed and modeled modes of variability in the context of various model deficiencies, where the observed modes are derived from the European Centre for Medium-Range Weather Forecasts analyses. Rotated empirical orthogonal function analysis is used to determine the primary modes of variability in the Pacific and Atlantic regions. EOFs are computed for both the zonal and meridional wind components. Time-lagged composite analysis is used to examine the temporal evolution of these modes, as well as their relationship to tropical convection. Wave activity flux vectors are used to examine further the characteristics of these intraseasonal modes and their relationship to tropical and extratropical forcing. It is found that the model simulates the extratropically forced modes well but simulates modes associated with tropical heating poorly. The poor tropical simulation is due primarily to the model's poor representation of the Madden-Julian oscillation (MJO). The model's inability to produce the MJO-related modes is reflected in the model upper-tropospheric wind field variability being too weak in the tropical and subtropical Indian and Pacific Ocean regions. Model biases in the simulated time-mean winds may also account for differences between the observed and modeled modes of variability. C1 USN,POSTGRAD SCH,DEPT METEOROL,MONTEREY,CA 93943. RP Reynolds, C (reprint author), USN,RES LAB,7 GRACE HOPPER AVE,STOP 2,MONTEREY,CA 93943, USA. OI Reynolds, Carolyn/0000-0003-4690-4171 NR 47 TC 9 Z9 9 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUN PY 1996 VL 124 IS 6 BP 1100 EP 1118 DI 10.1175/1520-0493(1996)124<1100:OASNHI>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UP593 UT WOS:A1996UP59300005 ER PT J AU Peng, MS Chang, SW AF Peng, MS Chang, SW TI Impacts of SSM/I retrieved rainfall rates on numerical prediction of a tropical cyclone SO MONTHLY WEATHER REVIEW LA English DT Article ID SURROUNDING WATERS; WEATHER PREDICTION; INITIALIZATION; MODEL; MICROWAVE; JAPAN AB Special Sensor Microwave/Imager (SSM/I) retrieved rainfall rates were assimilated into a limited-area numerical prediction model in an attempt to improve the initial analysis and forecast of a tropical cyclone. Typhoon Flo of 1990, which was observed in an intensive observation period of the Tropical Cyclone Motion Experiment-1990, was chosen for this study. The SSM/I retrieved rainfall rates within 888 km (8 degrees latitude) of the storm center were incorporated into the initial fields by a reversed Kuo cumulus parameterization. In the procedure used here, the moisture field in the model is adjusted so that the model generates the SSM/I-observed rainfall rates. This scheme is applied through two different assimilation methods. The first method is based on a dynamic initialization in which the prediction model is integrated backward adiabatically to t = -6 h and then forward diabatically for 6 h to the initial time. During the diabatic forward integration, the SSM/I rainfall rates are incorporated using the reversed Kuo cumulus parameterization. The second method is a forward data assimilation integration starting from t = -12 h. From t = -6 h to t = 0, the SSM/I rainfall rates are incorporated, also using the reversed Kuo scheme. During this period, the momentum fields are relaxed to the initial (t = 0) analysis to reduce the initial position error generated during the preforecast integration. Five cases for which SSM/I overpasses were available were tested, including two case's before and three after Flo's recurvature. Forecasts at 48 h are compared with the actual storm track and intensities estimated by the Joint Typhoon Warning Center. For the five cases tested, the assimilation of SSM/I retrieved rainfall rates reduced the average 48-h forecast distance error from 239 km in the control runs to 81 km in the assimilation experiments. It is postulated that the large positive impact was a consequence of the improved forecast intensity acid speed of the typhoon when the SSM/I rain-rate data were assimilated. C1 USN,RES LAB,MONTEREY,CA 93943. RP Peng, MS (reprint author), USN,POSTGRAD SCH,DEPT METEOROL,CODE MR-PG,589 DYER RD,MONTEREY,CA 93943, USA. NR 31 TC 18 Z9 18 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD JUN PY 1996 VL 124 IS 6 BP 1181 EP 1198 DI 10.1175/1520-0493(1996)124<1181:IOSRRR>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UP593 UT WOS:A1996UP59300010 ER PT J AU Tolles, WM AF Tolles, WM TI Nanoscience and nanotechnology in Europe SO NANOTECHNOLOGY LA English DT Review ID SCANNING-TUNNELING-MICROSCOPY; MOLECULAR-DYNAMICS SIMULATIONS; MAGNETIC FORCE MICROSCOPY; ION PROJECTION LITHOGRAPHY; SELF-ASSEMBLED MONOLAYERS; ELECTROSTATIC DEPOSITION TECHNIQUE; WANNIER-STARK LOCALIZATION; INGAAS/INP QUANTUM WIRES; SEXITHIOPHENE THIN-FILMS; FIELD-EFFECT TRANSISTOR AB During six months from April to September 1994, the author visited 42 laboratories in eight different European countries involved with research in nanostructures. The scientific thrusts point the way to new methods and properties of matter that may provide useful information. The potential applications of research in this field are likely to be found in information technology, sensors, and new materials, replete with the implications for many industrial interests. It is a suitable topic for the recently introduced 'focused technical assessment' activities of the Office of Naval Research Europe where the coordination for this effort was focused. Overviews of multidisciplinary efforts in fields of physics, electrical engineering, materials, chemistry, and biology are presented. RP Tolles, WM (reprint author), USN, RES LAB, WASHINGTON, DC 20375 USA. NR 309 TC 36 Z9 37 U1 4 U2 19 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD JUN PY 1996 VL 7 IS 2 BP 59 EP 105 DI 10.1088/0957-4484/7/2/001 PG 47 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA UX271 UT WOS:A1996UX27100001 ER PT J AU Dell, RF Eagle, JN Martins, GHA Santos, AG AF Dell, RF Eagle, JN Martins, GHA Santos, AG TI Using multiple searchers in constrained-path, moving-target search problems SO NAVAL RESEARCH LOGISTICS LA English DT Article ID GAMES AB The search theory open literature has paid little, if any, attention to the multiple-searcher, moving-target search problem. We develop an optimal branch-and-bound procedure and six heuristics for solving constrained-path problems with multiple searchers. Our optimal procedure outperforms existing approaches when used with only a single searcher. For more than one searcher, the time needed to guarantee an optimal solution is prohibitive. Our heuristics represent a wide variety of approaches: One solves partial problems optimally, two use paths based on maximizing the expected number of detections, two are genetic algorithm implementations, and one is local search with random restarts. A heuristic based on the expected number of detections obtains solutions within 2% of the best known for each one-, two-, and three-searcher test problem considered. For one- and two-searcher problems, the same heuristic's solution time is less than that of other heuristics. For three-searcher problems, a genetic algorithm implementation obtains the best-known solution inas little as 20% of other heuristic solution times. (C) 1996 John Wiley & Sons, Inc. C1 BRAZILIAN NAVY,CTR ANAL SISTEMAS NAVAIS,BR-20091 RIO JANEIRO,BRAZIL. RP Dell, RF (reprint author), USN,POSTGRAD SCH,DEPT OPERAT RES,MONTEREY,CA 93943, USA. NR 23 TC 31 Z9 31 U1 1 U2 3 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0894-069X J9 NAV RES LOG JI Nav. Res. Logist. PD JUN PY 1996 VL 43 IS 4 BP 463 EP 480 PG 18 WC Operations Research & Management Science SC Operations Research & Management Science GA UF071 UT WOS:A1996UF07100001 ER PT J AU Szu, H Telfer, B Garcia, J AF Szu, H Telfer, B Garcia, J TI Wavelet transforms and neural networks for compression and recognition SO NEURAL NETWORKS LA English DT Article DE adaptive wavelet transform; discrete wavelet transform; data compression; pattern recognition; neural networks ID AUTOMATIC TARGET RECOGNITION; REPRESENTATION; CLASSIFICATION; DISCRETE AB Robust recognition for image and speech processing needs data compression that preserves features. To accomplish this, we have utilized the discrete wavelet transforms and the continuous wavelet transforms (CWT) together with artificial neural networks (ANN) to achieve automatic pattern recognition. Our approach is motivated by the mathematical analog of the CWT to the human hearing and visual systems, e.g., the so-called Mexican hat and Gabor functions, Gaussian window, respectively. We develop an ANN method to construct an optimum mother wavelet that can organize sensor input data in the multiresolution format that seems to become essential for brain-style computing. In one realization, the architecture of our ANN is similar to that of a radial basis function approach, except that each node ir a wavelet having three learnable parameters: weight W-ij, scale a, and shift b. The node is not a McCullouch-Pitts neuron but a ''wave-on''. We still use a supervised learning conjugate gradient descent algorithm in these parameters to construct a ''super-mother'' wavelet from a superposition of a set of waveons-mother wavelets. Using these techniques, we can accomplish the signal-enhanced and feature-preserving compression, e.g., on the infrared images, that avoids the overtraining and overfitting that have plagued ANN's ability to generalize and abstract information. C1 USN,CTR SURFACE WARFARE,WASHINGTON,DC. NR 39 TC 58 Z9 62 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0893-6080 J9 NEURAL NETWORKS JI Neural Netw. PD JUN PY 1996 VL 9 IS 4 BP 695 EP 708 DI 10.1016/0893-6080(95)00051-8 PG 14 WC Computer Science, Artificial Intelligence SC Computer Science GA UT309 UT WOS:A1996UT30900011 ER PT J AU Abzug, R Webb, NJ AF Abzug, R Webb, NJ TI Another role for nonprofits: The case of mop-ups and nursemaids resulting from privatization in emerging economies SO NONPROFIT AND VOLUNTARY SECTOR QUARTERLY LA English DT Article ID UNFAIR-COMPETITION; ORGANIZATIONS; SECTOR AB This article synthesizes economic, sociological, and historical theory, first in the American context and then in an Pastern European (Polish) context, to develop an explanation fora distinctive type of nonprofit activity The authors explore a role for some nonprofits arising due to the privatization experience in the early history of the United States and to recent privatization in Poland (as an example of a transitioning economy), where nonprofits develop as facilitators for the creation of for-profit enterprises. The ''facilitator hypothesis'' proposes two roles for nonprofits. First, they ''mop up'' problems created when firms are privatized, assisting those persons left unemployed or otherwise adversely affected by privatization. Second, they act as ''nursemaids,'' nurturing nascent for-profit businesses and industries. This article suggests further study of emergent organizational forms in the transformation from command to market-oriented economies as a way to understand the diffusion of sectoral models from one economy to another. C1 USN, POSTGRAD SCH, MONTEREY, CA USA. RP Abzug, R (reprint author), NYU, STERN SCH BUSINESS, DEPT MANAGEMENT, NEW YORK, NY USA. NR 42 TC 4 Z9 4 U1 0 U2 0 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0899-7640 J9 NONPROF VOLUNT SEC Q JI Nonprofit Volunt. Sect. Q. PD JUN PY 1996 VL 25 IS 2 BP 156 EP 173 DI 10.1177/0899764096252002 PG 18 WC Social Issues SC Social Issues GA WY869 UT WOS:A1996WY86900002 ER PT J AU Regillo, CD Tidwell, J AF Regillo, CD Tidwell, J TI A small-incision technique for suturing a posterior chamber intraocular lens SO OPHTHALMIC SURGERY AND LASERS LA English DT Article ID CAPSULAR SUPPORT; FIXATION; ABSENCE AB The authors present a technique of transscleral fixation of a posterior chamber intraocular lens modified to permit a small-incision approach by using a foldable silicone lens. This modification improved intraoperative globe stability and reduced operative time. This procedure also has the potential for expediting postoperative recovery and visual rehabilitation. RP Regillo, CD (reprint author), USN,MED CTR,DEPT OPHTHALMOL,VITREORETINAL SERV,SAN DIEGO,CA 92134, USA. NR 5 TC 17 Z9 17 U1 0 U2 0 PU SLACK INC PI THOROFARE PA 6900 GROVE RD, THOROFARE, NJ 08086 SN 0022-023X J9 OPHTHALMIC SURG LAS JI Ophthalmic Surg. Lasers PD JUN PY 1996 VL 27 IS 6 BP 473 EP 475 PG 3 WC Ophthalmology; Surgery SC Ophthalmology; Surgery GA UQ410 UT WOS:A1996UQ41000012 PM 8782263 ER PT J AU Rosenberg, A Tonucci, RJ Lin, HB Campillo, AJ AF Rosenberg, A Tonucci, RJ Lin, HB Campillo, AJ TI Near-infrared two-dimensional photonic band-gap materials SO OPTICS LETTERS LA English DT Article ID INHIBITED SPONTANEOUS EMISSION; ARRAY AB We describe the fabrication and optical transmission of two-dimensional periodic dielectric structures with photonic band gaps in the near infrared. The structures consist of triangular arrays of air cylinders embedded in a glass matrix, with center-to-center nearest-neighbor separations between 1.08 and 0.73 mu m. The band gaps corresponding to the first Brillouin zone's boundaries occur at wavelengths between 2.5 and 1.1 mu m. For each array size, the band gaps along the two high-symmetry propagation directions are spectrally overlapped for light polarized perpendicular to the cylinder axes. The observed positions, widths, and polarization dependence of the band gaps are in good agreement with theoretical calculations. (C) 1996 Optical Society of America RP Rosenberg, A (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 10 TC 36 Z9 36 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUN 1 PY 1996 VL 21 IS 11 BP 830 EP 832 DI 10.1364/OL.21.000830 PG 3 WC Optics SC Optics GA UM401 UT WOS:A1996UM40100022 PM 19876173 ER PT J AU Mitchell, DK Van, R Mason, EH Norris, DM Pickering, LK AF Mitchell, DK Van, R Mason, EH Norris, DM Pickering, LK TI Prospective study of toxigenic Clostridium difficile in children given amoxicillin/clavulanate for otitis media SO PEDIATRIC INFECTIOUS DISEASE JOURNAL LA English DT Article DE Clostridium difficile; antibiotic-associated diarrhea; otitis media; antibiotic; diarrhea; toxigenic ID ANTIBIOTIC-ASSOCIATED DIARRHEA; DAY-CARE-CENTERS; PSEUDOMEMBRANOUS COLITIS; AMOXICILLIN-CLAVULANATE; ENZYME IMMUNOASSAYS; YOUNG-CHILDREN; CYTO-TOXIN; GASTROENTERITIS; POPULATION; ASTROVIRUS AB Objective. Evaluate antibiotic associated diarrhea and toxigenic Clostridium difficile in stool specimens obtained from children before and after 10 days of amoxicillin/clavulanate for otitis media. Design. Children, 12 to 47 months of age, treated with amoxicillin/clavulanate for otitis media in an outpatient setting were enrolled. Stool specimens were obtained at enrollment, when diarrhea occurred and at the end of therapy. All stool specimens were tested for C. difficile toxins A and B by enzyme immunoassay. Results. Seventy six children who had stool specimens collected at enrollment and after therapy were included in the analysis, None had C. difficile toxin in stool specimens at enrollment. Six (27%) of 22 children with diarrhea, and 4 (7%) of 54 children without diarrhea had C. difficile toxin present at completion of therapy (P = 0.03). Conclusion. Toxigenic C. difficile was identified in 13% of children at the conclusion of amoxicillin/clavulanate therapy with a significantly higher frequency in children with diarrhea. C1 EASTERN VIRGINIA MED SCH,NORFOLK,VA 23501. USN,MED CTR,PORTSMOUTH,VA. USN HOSP,NAPLES,ITALY. RP Mitchell, DK (reprint author), CHILDRENS HOSP KINGS DAUGHTERS,CTR PEDIAT RES,NORFOLK,VA 23507, USA. NR 41 TC 15 Z9 18 U1 0 U2 0 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0891-3668 J9 PEDIATR INFECT DIS J JI Pediatr. Infect. Dis. J. PD JUN PY 1996 VL 15 IS 6 BP 514 EP 519 DI 10.1097/00006454-199606000-00008 PG 6 WC Immunology; Infectious Diseases; Pediatrics SC Immunology; Infectious Diseases; Pediatrics GA UR267 UT WOS:A1996UR26700007 PM 8783348 ER PT J AU VanOrden, KF House, JF AF VanOrden, KF House, JF TI Spatial frequency-dependent asymmetry of visual evoked potential amplitudes SO PERCEPTUAL AND MOTOR SKILLS LA English DT Article ID PATTERN-REVERSAL; HEMISPHERIC-ASYMMETRY; RESPONSES; FIELD AB The extent to which pattern reversal evoked potential amplitudes are distributed symmetrically over the scalp was investigated as a function of stimulus spatial frequency. Nine right-handed male subjects viewed sinusoidal grating stimuli of 4.0 and 0.5 c/deg phase reversed every 900 msec. A visual half-field configuration enabled selective stimulation of the right- or left-hemisphere visual cortex. Evoked responses were recorded from the 2 cm above the inion (Oz) and at 7 and 13 cm lateral to Oz. Analyses of normalized evoked response amplitudes showed a significant asymmetry for the 4.0 c/deg stimulus; right-hemisphere amplitudes declined as a function of distance from the midline, while left-hemisphere amplitudes were,greatest at the 7 cm recording site. No hemispheric differences were observed for the 0.5 c/deg stimulus; amplitudes for both hemispheres declined as a function of distance from the midline. The data are discussed in terms of hemispheric differences in morphology and functional asymmetries at early levels of sensory processing. C1 USN, MED RES INST, ENVIRONM STRESS DEPT, WASHINGTON, DC USA. NR 16 TC 1 Z9 1 U1 1 U2 1 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0031-5125 EI 1558-688X J9 PERCEPT MOTOR SKILL JI Percept. Mot. Skills PD JUN PY 1996 VL 82 IS 3 BP 1011 EP 1018 PN 1 PG 8 WC Psychology, Experimental SC Psychology GA UP560 UT WOS:A1996UP56000055 PM 8774045 ER PT J AU Lall, R Jain, VK Johnson, WB AF Lall, R Jain, VK Johnson, WB TI Contemporary norms for the Coopersmith Self-esteem Inventory-Adult Form SO PERCEPTUAL AND MOTOR SKILLS LA English DT Article AB 422 medical personnel employed by the United States Navy were administered the Adult Form of the Coopersmith Self-esteem Inventory. In comparison to Coopersmith's 1981 normative sample, the current sample was substantially larger, geographically heterogeneous, and more reflective of the current national population. Analysis suggests small but consistent increases in mean self-esteem scores across all subgroups. Nonetheless, data from the current study are quite consistent with the findings from Coopersmith's 1981 normative sample. C1 KAHI MOHALA PSYCHIAT HOSP,HONOLULU,HI. GEORGE FOX COLL,NEWBERG,OR. RP Lall, R (reprint author), USN ACAD,DEPT LEADERSHIP & LAW,ANNAPOLIS,MD 21402, USA. NR 5 TC 5 Z9 5 U1 0 U2 0 PU PERCEPTUAL MOTOR SKILLS PI MISSOULA PA PO BOX 9229, MISSOULA, MT 59807 SN 0031-5125 J9 PERCEPT MOTOR SKILL JI Percept. Mot. Skills PD JUN PY 1996 VL 82 IS 3 BP 1136 EP 1138 PN 2 PG 3 WC Psychology, Experimental SC Psychology GA UW158 UT WOS:A1996UW15800016 ER PT J AU Gillespie, DT AF Gillespie, DT TI Why quantum dynamics can be formulated as a Markov process - Comment SO PHYSICAL REVIEW A LA English DT Letter AB In a paper with the title given above, Garbaczewski and Olkiewicz [Phys. Rev. A 51, 3445 (1995)] claim that a contrarily entitled paper of Gillespie [Phys. Rev. A 49, 1607 (1994)] is misleading because it is based on an allegedly overly restrictive assumption. In the discussion given here of that claim, the impugned assumption, and some foundational aspects of Markovian and non-Markovian stochastic processes, it is concluded that the thesis of the later title has not been established. RP Gillespie, DT (reprint author), USN,AIR WAREFARE CTR,RES & TECHNOL DIV,CHINA LAKE,CA 93555, USA. NR 6 TC 4 Z9 4 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JUN PY 1996 VL 53 IS 6 BP 4602 EP 4604 DI 10.1103/PhysRevA.53.4602 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA UR605 UT WOS:A1996UR60500117 ER PT J AU Luscombe, JH Luban, M Reynolds, JP AF Luscombe, JH Luban, M Reynolds, JP TI Finite-size scaling of the Glauber model of critical dynamics SO PHYSICAL REVIEW E LA English DT Article AB We obtain the exact critical relaxation time tau(L)(xi), where xi is the bulk correlation length, for the Glauber kinetic Ising model of spins on a one-dimensional lattice of finite length L for both periodic and free boundary conditions (BC's). We show that, independent of the BC's, the dynamic critical exponent has the well-known value z=2, and we comment on a recent claim that z=1 for this model. The ratio tau(L)(xi)/tau(infinity)(xi), in the double limit L,xi-->infinity for fixed x=L/xi, approaches a limiting functional form, f(tau)(L/xi), the finite-size scaling function. For free BC's we derive the exact scaling function f(tau)(x) = [1+(omega(x)/(x)(2)](-1), where omega(x) is the smallest root of the transcendental equation omega tan(omega/2)=x. We provide expansions of omega(x) in powers of x and x(-1) for the regimes of small and large x, respectively, and establish their radii of convergence. The scaling function shows anomalous behavior at small x, f(tau)(x)approximate to x, instead of the usual f(tau)(x)approximate to x(z), as x-->O. This is because, even for finite L, the lifetime of the slowest dynamical mode diverges for T-->0 K. For periodic BC's, with the exception of one system, sigma(L) is independent of L, and hence f(tau)=1. The exceptional system, that with an odd number of spins and antiferromagnetic couplings, exhibits frustration at T=O K, and the scaling function is given by f(tau)(x)=[1+(pi/x)(2)](-1). C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP Luscombe, JH (reprint author), USN,POSTGRAD SCH,DEPT PHYS,MONTEREY,CA 93943, USA. NR 17 TC 34 Z9 34 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUN PY 1996 VL 53 IS 6 BP 5852 EP 5860 DI 10.1103/PhysRevE.53.5852 PN A PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA UR606 UT WOS:A1996UR60600044 ER PT J AU Esarey, E Sprangle, P Hafizi, B Serafim, P AF Esarey, E Sprangle, P Hafizi, B Serafim, P TI Radiation generation by photoswitched, periodically biased semiconductors SO PHYSICAL REVIEW E LA English DT Article ID ELECTROMAGNETIC PULSES AB A laser pulse, propagating nearly parallel to the surface of a planar semiconductor wafer, will generate electron-hole pairs. If the semiconductor is spatially biased with a static electric field of period lambda(0), the laser pulse acts as a fast switch and generates a periodic current. The rapid switching of the current generates radiation, which propagates along the surface and can be confined by a conducting wall placed parallel to the wafer. The wavelength of the radiation can be tuned by adjusting lambda(0), the wafer-wall separation, and/or the carrier density. In the absence of collisional damping, N-0 periods of the static bias electric field will generate N-0 periods of radiation. Under idealized conditions, the maximum electric field of the radiation is equal to the applied static held and the maximum efficiency of converting the static electric field energy to electromagnetic energy is 30%. In practice for typical parameters, tunable electromagnetic radiation can be generated with wavelengths in the 50-500-mu m range, pulse durations in the picosecond or subpicosecond range, and peak powers on the order of 100 W. RP Esarey, E (reprint author), USN, RES LAB, DIV PLASMA PHYS, BEAM PHYS BRANCH, WASHINGTON, DC 20375 USA. NR 14 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD JUN PY 1996 VL 53 IS 6 BP 6419 EP 6426 DI 10.1103/PhysRevE.53.6419 PN B PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA UR607 UT WOS:A1996UR60700039 ER PT J AU Grinstein, FF Gutmark, EJ Parr, TP HansonParr, DM Obeysekare, U AF Grinstein, FF Gutmark, EJ Parr, TP HansonParr, DM Obeysekare, U TI Streamwise and spanwise vortex interaction in an axisymmetric jet. A computational and experimental study SO PHYSICS OF FLUIDS LA English DT Article ID TURBULENT MIXING LAYERS; ELLIPTIC JETS; SHEAR FLOWS; COHERENT; DYNAMICS; SIMULATION; RELEASE; FLAMES AB The near-field of an azimuthally excited round jet was investigated in a combined computational/experimental study. The reaction zones in the jet were visualized using OH Planar-Laser-Induced-Fluorescence (PLIF) diagnostics. Both axisymmetric and azimuthal modes of the jet were excited to stabilize its spatial structure. Three-dimensional flame visualization of the laboratory jet reconstructed from multiple two-dimensional images acquired at constant phase angle, reveal a complex structure of the reaction zone. Time-dependent numerical simulations provided insight into the underlying fluid-dynamical processes leading to this flame structure. Simulations of reactive and non-reactive free jets used a Monotonically Integrated Large-Eddy-Simulation (MILES) approach, multi-species diffusive transport, global finite-rate chemistry and appropriate inflow/outflow boundary conditions. The flow visualizations of the experimental and computational jets strongly resemble each other, revealing tight coupling between axisymmetric vortex rings and braid (rib) vortices. The jet vorticity evolution is dominated by the dynamics of vortex-ring self-deformation induced by the azimuthal excitation imposed at the jet exit, the dynamics of rib vortices forming in the braid regions between undulating vortex rings, and strong interactions between rings and ribs. The observed topological features of the flow are directly related to the nearly-inviscid jet vorticity dynamics. These processes affect the mixing pattern of the jet, resulting in localized regions of high fuel concentration leading to combustion inactive regions in the flame, and other regions with enhanced mixing and a proper air-to-fuel ratio in the flame where the combustion process is intense. The vorticity dynamics and ensuing mixing processes determine the regions of combustion within the flame and thus the overall heat release pattern. (C) 1996 American Institute of Physics. C1 USN,AWC,PROP RES BRANCH,CHINA LAKE,CA 93555. USN,RES LAB,CTR COMPUTAT SCI,WASHINGTON,DC 20375. RP Grinstein, FF (reprint author), USN,RES LAB,COMPUTAT PHYS & FLUID DYNAM LAB,CODE 6410,WASHINGTON,DC 20375, USA. OI Gutmark, Ephraim/0000-0001-7816-4257 NR 34 TC 37 Z9 37 U1 0 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD JUN PY 1996 VL 8 IS 6 BP 1515 EP 1524 DI 10.1063/1.868927 PG 10 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA UM418 UT WOS:A1996UM41800021 ER PT J AU Jain, VK Lall, R AF Jain, VK Lall, R TI Nurses' personality types based on the Myers-Briggs Type Indicator SO PSYCHOLOGICAL REPORTS LA English DT Article AB One personality type was common for 15 of 34 nurses administered the Myers Briggs Type Indicator. C1 KAHI MOHALA PSYCHIAT HOSP,HONOLULU,HI. USN ACAD,ANNAPOLIS,MD 21402. NR 4 TC 5 Z9 5 U1 0 U2 2 PU PSYCHOLOGICAL REPORTS PI MISSOULA PA P O BOX 9229, MISSOULA, MT 59807 SN 0033-2941 J9 PSYCHOL REP JI Psychol. Rep. PD JUN PY 1996 VL 78 IS 3 BP 938 EP 938 PN 1 PG 1 WC Psychology, Multidisciplinary SC Psychology GA UQ543 UT WOS:A1996UQ54300043 PM 8711050 ER PT J AU Segall, DO AF Segall, DO TI Multidimensional adaptive testing SO PSYCHOMETRIKA LA English DT Article DE computerized adaptive testing; mathematical models; multidimensional adaptive testing; multidimensional item response theory; reliability; tests ID UNIDIMENSIONALITY ASSUMPTION; LOGISTIC MODEL; IRT AB Maximum likelihood and Bayesian procedures for item selection and scoring of muitidimensional adaptive tests are presented. A demonstration using simulated response data illustrates that multidimensional adaptive testing (MAT) can provide equal or higher reliabilities with about one-third fewer items than are required by one-dimensional adaptive testing (OAT). Furthermore, holding test-length constant across the MAT and OAT approaches, substantial improvements in reliability can be obtained from multidimensional assessment. A number of issues relating to the operational use of multidimensional adaptive testing are discussed. C1 USN,CTR PERSONNEL RES & DEV,WASHINGTON,DC 20350. NR 38 TC 92 Z9 95 U1 0 U2 3 PU PSYCHOMETRIC SOC PI WILLIAMSBURG PA COLLEGE OF WILLIAM AND MARY DEPT PSYCHOLOGY, WILLIAMSBURG, VA 23185 SN 0033-3123 J9 PSYCHOMETRIKA JI Psychometrika PD JUN PY 1996 VL 61 IS 2 BP 331 EP 354 DI 10.1007/BF02294343 PG 24 WC Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods; Psychology, Mathematical SC Mathematics; Mathematical Methods In Social Sciences; Psychology GA UN533 UT WOS:A1996UN53300008 ER PT J AU Young, FC Boller, JR Stephanakis, SJ AF Young, FC Boller, JR Stephanakis, SJ TI Absolute calibration of nuclear activation diagnostics for intense pulsed ion beams SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB Absolute calibration of an annihilation-radiation NaI coincidence detection system for short-lived ion-induced radioactivity is described. Calibration with a Na-22 radioactive source is compared with an independent calibration using the (12)(p,gamma)N-13(beta(+)) reaction with 1 MeV protons from a Van de Graaff accelerator. These calibrations are consistent, provided correction for summing of the 0.51 and 1.27 MeV gamma rays from the Na-22 source in the NaI detectors is included. This summing correction depends on the total efficiency for detecting 1.27 MeV gamma rays and can alter the calibration by as much as a factor of 2, depending on the size and separation of the detectors. A procedure to determine this correction using Co-60 and Na-22 radioactive sources is described. These two calibrations give a thick-target yield for the C-12(p,gamma)N-13 reaction at 1 MeV of (8.0 +/- 0.4)x10(-10) reactions/proton. Intense pulsed proton fluences of 0.08 to 3.7 cal/cm(2), determined by coincidence counting beta(+) annihilation radiation produced by the C-12(p,gamma)N-13(beta(+)) reaction, are in agreement with ion-beam fluences measured independently with carbon calorimeters on the same carbon sample. RP Young, FC (reprint author), USN,RES LAB,DIV PLASMA PHYS,WASHINGTON,DC 20375, USA. NR 16 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 1996 VL 67 IS 6 BP 2182 EP 2188 DI 10.1063/1.1147048 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UR222 UT WOS:A1996UR22200023 ER PT J AU Phillips, PM Hor, C Malsawma, L Jensen, KL Zaidman, EG AF Phillips, PM Hor, C Malsawma, L Jensen, KL Zaidman, EG TI Design and construction of apparatus for characterization of gated field emitter array electron emission SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB An inchworm controlled microfabricated detector system with laser interferometric feedback has been developed to provide an absolute position characterization of the electron emission from gated field emitter arrays (FEAs) in an ultra-high-vacuum (UHV) environment with nanometric precision. The emission characteristics of single tip and multiple tip FEAs are required to provide comparison with theory and simulation in order for these to be predictably used as a reliable source of high current density for high frequency amplifiers and oscillators. In its present form, the instrumentation is used to determine the angular distribution of the field emitted electrons. The addition of a few components will allow the measurement of emittance of the FEAs for electron gun design. Angular distribution of the electrons is measured by means of a microfabricated detector which is manipulated within an UHV environment with nanometric precision. The absolute location of the detector (within 80 nm uncertainty) is determined via laser interferometry. The details of the instrumentation with some preliminary experimental results are shown. (C) 1996 American Institute of Physics. C1 USN,RES LAB,DIV ELECTR SCI & TECHNOL,WASHINGTON,DC 20375. RP Phillips, PM (reprint author), SCI APPLICAT INT CORP,MCLEAN,VA 22102, USA. RI Jensen, Kevin/I-1269-2015 OI Jensen, Kevin/0000-0001-8644-1680 NR 15 TC 6 Z9 6 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 1996 VL 67 IS 6 BP 2387 EP 2393 DI 10.1063/1.1147007 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UR222 UT WOS:A1996UR22200056 ER PT J AU Marino, A AF Marino, A TI Multibeam, wide-swath, parametric, sub-bottom profiler SO SEA TECHNOLOGY LA English DT Article RP Marino, A (reprint author), USN,COMMAND CONTROL & OCEAN SURVEILLANCE CTR,RDT&E DIV NRAD,WARMINSTER,PA 18974, USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 8 TC 0 Z9 0 U1 0 U2 1 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD JUN PY 1996 VL 37 IS 6 BP 39 EP & PG 5 WC Engineering, Ocean SC Engineering GA UT536 UT WOS:A1996UT53600006 ER PT J AU Weiser, MR Gibbs, SAL Valeri, CR Shepro, D Hechtman, HB AF Weiser, MR Gibbs, SAL Valeri, CR Shepro, D Hechtman, HB TI Anti-selectin therapy modifies skeletal muscle ischemia and reperfusion injury SO SHOCK LA English DT Article ID LEUKOCYTE ADHESION MOLECULE-1; GRANULE MEMBRANE-PROTEIN; LOWER TORSO ISCHEMIA; P-SELECTIN; COMPLEMENT ACTIVATION; MONOCLONAL-ANTIBODIES; LUNG INJURY; NEUTROPHIL; BLOCKADE; ADHERENCE AB Restoration of blood flow to ischemic skeletal muscle results in a reperfusion injury characterized by permeability edema in part mediated by neutrophils that adhere via the selectin family of adhesion molecules. Rats underwent 4 h of hindlimb tourniquet ischemia followed by 4 h of reperfusion, The role of neutrophils was determined by rendering one group of animals neutropenic before ischemia. In additional experimental groups, selectins were blocked with either a soluble form of the selectin counter-receptor, sialyl-lewis X (SLX) or a monoclonal antibody directed against P-selectin (PB1.3). Neutrophil depletion resulted in a 36.1% reduction in hindlimb permeability (p < .05). SU( reduced hindlimb permeability index (PI) 23.9% at 1 mg/kg and 36.1% at 10 mg/kg compared to a nonfucosylated oligosaccharide, sialyl-N-acetylactosamine (p < .05). SLX also reduced neutrophil sequestration by 48.6% (p < .05). PB1.3 reduced hindlimb injury by 26.5% (p < .05) but did not reduce leukosequestration. We interpret these data to indicate that ischemia and reperfusion lead to selectin-mediated neutrophil sequestration. The oligosaccharide SU(, while moderately effective in limiting neutrophil sequestration was as effective as neutrophil depletion in reducing hindlimb permeability. The lack of concordance between the ability of SW and PB1.3 in limiting neutrophil sequestration and permeability indicate mechanisms of action of these two agents that are in addition to the blocking of adhesion. C1 HARVARD UNIV,BRIGHAM & WOMENS HOSP,SCH MED,DEPT SURG,BOSTON,MA 02115. BOSTON UNIV,CTR BIOL SCI,BOSTON,MA 02115. USN,BLOOD RES LAB,BOSTON,MA 02115. FU NHLBI NIH HHS [HL 43875-03]; NIGMS NIH HHS [GM07560-18, GM 35141-09] NR 35 TC 32 Z9 32 U1 0 U2 0 PU BIOMEDICAL PRESS PI AUGUSTA PA 1021 15TH ST, BIOTECH PARK STE 9, AUGUSTA, GA 30901 SN 1073-2322 J9 SHOCK JI Shock PD JUN PY 1996 VL 5 IS 6 BP 402 EP 407 DI 10.1097/00024382-199606000-00003 PG 6 WC Critical Care Medicine; Hematology; Surgery; Peripheral Vascular Disease SC General & Internal Medicine; Hematology; Surgery; Cardiovascular System & Cardiology GA UR938 UT WOS:A1996UR93800003 PM 8799951 ER PT J AU Nindos, A Alissandrakis, CE Gelfreikh, GB Kundu, MR Dere, KP Korzhavin, AN Bogod, VM AF Nindos, A Alissandrakis, CE Gelfreikh, GB Kundu, MR Dere, KP Korzhavin, AN Bogod, VM TI A model for active region emission at centimeter wavelengths SO SOLAR PHYSICS LA English DT Article ID VLA OBSERVATIONS; CORONAL LOOPS; SOLAR; POLARIZATION; FILAMENT; 6-CM; SUN AB We present multi-frequency observations and model computations of the microwave emission of a solar active region. The radio observations were obtained with the RATAN-600 at several wavelengths between 0.8 and 31.6 cm and with the VLA at 6 and 20 cm. The active region was also observed in the EUV O IV lines by the HRTS instrument aboard the Space Shuttle Spacelab-2 mission. These lines are formed in the chromosphere-corona transition region and their intensity ratio is sensitive to pressure. Photospheric magnetograms provided both the longitudinal and the transverse component of the magnetic field. The microwave observations were checked against model computations taking into account both the free-free and the gyro-resonance emission mechanisms and using the pressure data from the O IV lines. The magnetic field was computed through constant-a! force-free extrapolations of the longitudinal photospheric field. We computed both the flux from 2 to 20 cm and the spatial structure of the microwave emission at 6 and 20 cm. The comparison of the computed and observed flux spectra allowed us to estimate the magnetic field strength at the base of the transition region and in the low corona, as well as the values of the conductive flux and the height of the base of the transition region. The model maps at 6 cm and 20 cm showed that ct was not constant above the active region; the same conclusion was reached on the basis of the photospheric observations. The use of pressure measurements allowed us to identify microwave structures which were determined by pressure enhancements. At 6 cm the computations confirmed the fact that the magnetic field is the principal factor that determines the structure of sunspot-associated sources and showed that the effect of pressure variations was small. Pressure variations were more important at 20 cm, where the peak of the emission was associated with the sunspot and a diffuse component was associated with the plage which had an average pressure higher by a factor of 1.54 than the sunspot. C1 UNIV IOANNINA,DEPT PHYS,SECT ASTROGEOPHYS,GR-45110 IOANNINA,GREECE. RUSSIAN ACAD SCI,MAIN ASTRON OBSERV,ST PETERSBURG 196140,RUSSIA. UNIV MARYLAND,DEPT ASTRON,COLLEGE PK,MD 20742. USN,RES LAB,EO HULBURT CTR SPACE RES,WASHINGTON,DC 20375. RUSSIAN ACAD SCI,SPECIAL ASTROPHYS OBSERV,ST PETERSBURG BRANCH,ST PETERSBURG 196140,RUSSIA. RP Nindos, A (reprint author), UNIV ATHENS,DEPT PHYS,ASTROPHYS ASTRON & MECH SECT,GR-15784 ATHENS,GREECE. RI Bogod, Vladimir/A-2315-2017 NR 25 TC 8 Z9 8 U1 1 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD JUN PY 1996 VL 166 IS 1 BP 55 EP 87 PG 33 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UL847 UT WOS:A1996UL84700004 ER PT J AU Boske, T Kielwein, M Knupfer, M Barman, SR Behr, G Buchgeister, M Golden, MS Fink, J Singh, DJ Pickett, WE AF Boske, T Kielwein, M Knupfer, M Barman, SR Behr, G Buchgeister, M Golden, MS Fink, J Singh, DJ Pickett, WE TI Core electron spectroscopic studies of YNi2B2C SO SOLID STATE COMMUNICATIONS LA English DT Article DE superconductors; electronic band structure; electron-electron correlation; electron energy loss spectroscopy; photoelectron spectroscopy ID X-RAY PHOTOEMISSION; FERROMAGNETIC NICKEL; AUGER-SPECTRA; NI 2P; DICHROISM; BAND AB High-energy electron energy-loss spectroscopy in transmission has been applied to obtain the absorption spectra at the B 1s, C 1s and Ni 2p(3/2) excitation edges of bulk polycrystalline YNi2B2C. We find a close similarity in the near-edge structures and confirm the strongly covalent character of the bonding between Ni, B and C. We compare our results to band structure calculations of the local unoccupied density of states generated within the local density approximation. From x-ray photoemission spectroscopy measurements we determine the core level binding energies and from a comparison of photoemission and Auger spectroscopic measurements we derive a value of the Ni d-d Coulomb energy U-A of about 4 eV. Copyright (C) 1996 Elsevier Science Ltd. C1 USN,RES LAB,COMPLEX SYST THEORY BRANCH,WASHINGTON,DC 20375. RP Boske, T (reprint author), IFW DRESDEN EV,INST FESTKORPERFORSCH,POSTFACH 270016,D-01171 DRESDEN,GERMANY. RI Golden, Mark/D-3469-2011; Roy Barman, Sudipta/B-2026-2010 NR 33 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD JUN PY 1996 VL 98 IS 9 BP 813 EP 817 DI 10.1016/0038-1098(96)00133-0 PG 5 WC Physics, Condensed Matter SC Physics GA UM381 UT WOS:A1996UM38100010 ER PT J AU Singh, DJ AF Singh, DJ TI Electronic properties of YNi2B2C SO SOLID STATE COMMUNICATIONS LA English DT Article DE superconductors; electronic structure ID STATE AB Calculations of electronic structure and Fermi surface related quantities for YNi2B2C are reported and discussed in relation to transport data. The results are qualitatively similar to those obtained for other materials in this family, and are consistent with a picture of this material as a conventional strong coupling superconductor with nearly isotropic properties. Copyright (C) 1996 Elsevier Science Ltd RP Singh, DJ (reprint author), USN,RES LAB,COMPLEX SYST THEORY BRANCH,WASHINGTON,DC 20375, USA. RI Singh, David/I-2416-2012 NR 27 TC 23 Z9 23 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD JUN PY 1996 VL 98 IS 10 BP 899 EP 902 DI 10.1016/0038-1098(95)00828-4 PG 4 WC Physics, Condensed Matter SC Physics GA UM658 UT WOS:A1996UM65800009 ER PT J AU Walters, RJ Messenger, SR Cotal, HL Summers, GP Burke, EA AF Walters, RJ Messenger, SR Cotal, HL Summers, GP Burke, EA TI Electron and proton irradiation-induced degradation of epitaxial InP solar cells SO SOLID-STATE ELECTRONICS LA English DT Article ID RADIATION AB The degradation of epitaxial, shallow homojunction n + p InP solar cells under 1 MeV electron and 3 MeV proton irradiation is presented. The data measured under 3 MeV proton irradiation are analyzed in terms of displacement damage dose which is the product of the particle fluence and the calculated non-ionizing energy loss (NIEL)[1]. A characteristic proton degradation curve is derived from which the cell degradation under any energy proton irradiation can be calculated. The data measured under 1 MeV electron irradiation is also analyzed in terms of displacement damage dose. The electron irradiation-induced degradation is correlated with the proton degradation curve by determining electron to proton dose ratios for each of the photovoltaic (PV) parameters. A comparison of the characteristic degradation curves for InP and GaAs/Ge solar cells, which was determined previously, shows InP to be intrinsically more resistant to displacement energy deposition. The base carrier concentration was measured during the irradiations, and significant carrier removal was observed. When analyzed as a function of displacement damage dose, the reduction in carrier concentration under both the 1 MeV electron and the 3 MeV proton irradiation is shown to follow the same degradation curve. From this common degradation curve, a characteristic carrier removal rate is calculated for InP under any irradiation. The junction dark current was also measured during both irradiations, and the data were fit to a three-term diode dark current equation. From the fits, the diffusion current is determined as a function of particle fluence. Changes in the diffusion current under electron and proton irradiation are shown to correlate in terms of displacement damage dose in the same way as the cell maximum power. The junction recombination current is also determined from the dark current data, and the results show the energy level of the dominant radiation-induced recombination center to be approximately the same in both the electron and proton irradiated samples. In addition, the dark current analysis indicates that the relative changes in the hole and electron lifetimes are essentially the same under both the electron and the proton irradiations. Based on these results and the overall correlation between the electron and proton damage, a detailed description of the mechanism of the radiation response of InP is developed which describes the cell degradation under any particle irradiation. C1 SFA INC,LANDOVER,MD 20785. UNIV BALTIMORE,DEPT PHYS,BALTIMORE,MD 21228. RP Walters, RJ (reprint author), USN,RES LAB,CODE 6615,WASHINGTON,DC 20375, USA. NR 15 TC 20 Z9 20 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD JUN PY 1996 VL 39 IS 6 BP 797 EP 805 DI 10.1016/0038-1101(95)00342-8 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA UN324 UT WOS:A1996UN32400005 ER PT J AU Gibbs, SAL Weiser, MR Kobzik, L Valeri, CR Shepro, D Hechtman, HB AF Gibbs, SAL Weiser, MR Kobzik, L Valeri, CR Shepro, D Hechtman, HB TI P-selectin mediates intestinal ischemic injury by enhancing complement deposition SO SURGERY LA English DT Article ID REPERFUSION INJURY; NEUTROPHIL; ADHESION; LEUKOCYTES; RAT AB Background. Ischemia and reperfusion injury of rodent intestine is complement mediated. P-seletin antagonism reduces local injury, yet neutrophil depletion does not. This study tests the thesis that the protective mechanism of P-selectin antagonists involves complement inhibition. Methods. We subjected rats (n=86) to 50 minutes of complete mesenteric ischemia and 4 hours of reperfusion. Treatment with a monoclonal antibody (PB1.3) against P-selectin reduced intestinal injury as judged by I-125-albumin permeability index (7.33 +/- 0.40) compared with saline solution treatment (11.4 +/- 0.49) (p <0.05). Results. However, intestinal neutrophil sequestration assessed by myeloperoxidase assay was unchanged. Immunohistochemistry revealed that mucosal C5b-9 was deposited in animals treated with saline solution and was absent in the sham group. PB1.3 treatment reduced C5b-9 deposition in the intestinal mucosa compared with that in animals treated with saline solution (p <0.05). Neutrophil-dependant remote lung injury assessed by I-125-albumin permeability and pulmonary myeloperoxidase assay were not significantly reduced by PB1.3. Treatment with a soluble form of P-selectin ligand, sialyl Lewis(x) (sLe(x)), reduced intestinal myeloperoxidase (0.065 +/- 0.006) compared with saline solution treatment (0.136 +/- 0.02) (p <0.05), but it did not reduce permeability. Remote lung permeability was reduced (4.52 +/- 0.65 x 10(-3)) by sLe(x) compared with saline solution treatment (6.11 +/- 0.41 x 10(-3)) (p <0.05). Conclusions. Antagonizing the lectin domain of P-selectin and thereby neutrophil adhesion was without local benefit in this model. In contrast, PB1.3 extend a novel antagonism of P-selectin and reduced complement deposition. C1 BRIGHAM & WOMENS HOSP,DEPT SURG,BOSTON,MA 02115. BRIGHAM & WOMENS HOSP,DEPT PATHOL,BOSTON,MA 02115. HARVARD UNIV,SCH MED,BOSTON,MA. USN,BLOOD RES LAB,BOSTON,MA. BOSTON UNIV,CTR BIOL SCI,BOSTON,MA 02215. FU NHLBI NIH HHS [HL43875-02]; NIGMS NIH HHS [GM34141-06, GM24891-14] NR 22 TC 29 Z9 30 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 SN 0039-6060 J9 SURGERY JI Surgery PD JUN PY 1996 VL 119 IS 6 BP 652 EP 656 DI 10.1016/S0039-6060(96)80189-9 PG 5 WC Surgery SC Surgery GA UP967 UT WOS:A1996UP96700007 PM 8650605 ER PT J AU Inamdar, A Sintasath, DM Husted, L Henson, V Ng, J Hartzman, RJ Hurley, CK AF Inamdar, A Sintasath, DM Husted, L Henson, V Ng, J Hartzman, RJ Hurley, CK TI Typing the HLA-B locus by a nested primer approach and oligonucleotide hybridization SO TISSUE ANTIGENS LA English DT Article DE HLA-B allele; nested PCR; group-specific; amplification; PGR-SSOP AB A system for intermediate level identification of the HLA-B locus alleles was devised. This system can be extended to identify individual alleles in any sample. The first step used primers which amplify all HLA-B alleles. This amplicon was subjected to SSOP hybridization to allow intermediate level typing of samples. In the second step, group-specific primers were utilized to obtain specific amplification of groups consisting of a few alleles. The oligotypes within each group were identified by the use of SSOP. The separation of groups of alleles by amplification allowed the use of a limited number of probes to identify oligotypes present in a sample. Additional probes can be added as new alleles are identified, increasing the flexibility of the system. HLA typing software was developed to determine the resolution of the system and to identify HLA oligotypes. PCR-SSOP methods are in wide use and have been extensively validated. The procedures reported here will be relatively easy to implement for large-scale DNA-based typing of the HLA-B locus. C1 GEORGETOWN UNIV,MED CTR,DEPT PEDIAT,WASHINGTON,DC 20007. USN,MED RES INST,BETHESDA,MD. DEPT MICROBIOL & IMMUNOL,BETHESDA,MD. FU NCI NIH HHS [P30CA15008] NR 22 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 0001-2815 J9 TISSUE ANTIGENS JI Tissue Antigens PD JUN PY 1996 VL 47 IS 6 BP 519 EP 529 DI 10.1111/j.1399-0039.1996.tb02594.x PG 11 WC Cell Biology; Immunology; Pathology SC Cell Biology; Immunology; Pathology GA UT073 UT WOS:A1996UT07300010 PM 8813741 ER PT J AU Raglin, JS OConnor, PJ Carlson, N Morgan, WP AF Raglin, JS OConnor, PJ Carlson, N Morgan, WP TI Responses to underwater exercise in scuba divers differing in trait anxiety SO UNDERSEA & HYPERBARIC MEDICINE LA English DT Article DE scuba diving; psychology; panic ID INDUSTRIAL RESPIRATORS; PANIC DISORDER; HYPERVENTILATION AB Fifteen male scuba divers performed underwater leg ergometer exercise in an effort to determine if trait anxiety was related to their physiologic or perceptual responses. Psychologic assessment completed before exercise testing revealed that the sample exhibited positive psychologic profiles. However, five individuals possessed trait anxiety scores above the published mean (M = 46.0). Their responses to exercise were compared with the five participants with the lowest trait anxiety scores (M = 30.6). The exercise task was 20 min of steady-state underwater leg ergometer exercise. Oxygen consumption, CO2 production, minute ventilatory volume, breathing frequency, and heart rate were assessed at rest and every 5 min during exercise. Perception of effort and breathing discomfort were also determined during exercise. Each of the physiologic and perceptual variables increased (P < 0.05) with exercise. The only group main effect (P < 0.05) occurred for respiration rate. The high trait anxious group took 7.4 fewer breaths per minute (13.1 vs. 20.5) compared with low trait anxious group. These results have implications regarding the use of intervention strategies in persons at potential risk of experiencing panic while scuba diving. C1 UNIV GEORGIA,DEPT EXERCISE SCI,ATHENS,GA 30602. USN,SUBMARINE MED RES LAB,SUBMARINE BASE NEW LONDON,GROTON,CT. UNIV WISCONSIN,DEPT KINESIOL,MADISON,WI. RP Raglin, JS (reprint author), INDIANA UNIV,DEPT KINESIOL,BLOOMINGTON,IN 47405, USA. NR 25 TC 6 Z9 8 U1 3 U2 4 PU UNDERSEA & HYPERBARIC MEDICAL SOC INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 1066-2936 J9 UNDERSEA HYPERBAR M JI Undersea Hyperb. Med. PD JUN PY 1996 VL 23 IS 2 BP 77 EP 82 PG 6 WC Marine & Freshwater Biology; Medicine, Research & Experimental SC Marine & Freshwater Biology; Research & Experimental Medicine GA UY285 UT WOS:A1996UY28500002 PM 8840475 ER PT J AU Tritt, TM AF Tritt, TM TI Thermoelectrics run hot and cold SO SCIENCE LA English DT Editorial Material C1 CLEMSON UNIV,DEPT PHYS,CLEMSON,SC 29634. RP Tritt, TM (reprint author), USN,RES LAB,MAT PHYS BRANCH,CODE 6341,WASHINGTON,DC 20375, USA. NR 12 TC 128 Z9 134 U1 4 U2 27 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAY 31 PY 1996 VL 272 IS 5266 BP 1276 EP 1277 DI 10.1126/science.272.5266.1276 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UN472 UT WOS:A1996UN47200026 ER PT J AU Park, JH Chen, CT Cheong, SW Bao, W Meigs, G Chakarian, V Idzerda, YU AF Park, JH Chen, CT Cheong, SW Bao, W Meigs, G Chakarian, V Idzerda, YU TI Electronic aspects of the ferromagnetic transition in manganese perovskites SO PHYSICAL REVIEW LETTERS LA English DT Article ID LA1-XSRXMNO3; ABSORPTION AB We have investigated the electronic structure associated with the ferromagnetic transition of La1-xCaxMnO3 and La1-xPbxMnO3 using high resolution photoemission, Mn 2p resonant photoemission, and O 1s x-ray absorption spectroscopies. The data clearly show that the band gap collapses below the Curie temperature (T-C) and the density of states at the Fermi level increases with cooling, providing a conclusive microscopic evidence for an insulator-metal transition. Our results suggest that strong small polaron effects, which contribute to a charge fluctuation energy of similar to 1.5 eV, are responsible for the insulating behavior above T-C which has been enigmatic in the double-exchange model. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Park, JH (reprint author), AT&T BELL LABS,600 MT AVE,MURRAY HILL,NJ 07974, USA. RI Bao, Wei/E-9988-2011 OI Bao, Wei/0000-0002-2105-461X NR 29 TC 280 Z9 285 U1 2 U2 17 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 27 PY 1996 VL 76 IS 22 BP 4215 EP 4218 DI 10.1103/PhysRevLett.76.4215 PG 4 WC Physics, Multidisciplinary SC Physics GA UM245 UT WOS:A1996UM24500029 ER PT J AU Choi, JJ Armstrong, CM Calise, F Ganguly, AK Kyser, RH Parks, GS Parker, RK Wood, F AF Choi, JJ Armstrong, CM Calise, F Ganguly, AK Kyser, RH Parks, GS Parker, RK Wood, F TI Experimental observation of coherent millimeter wave radiation in a folded waveguide employed with a gyrating electron beam SO PHYSICAL REVIEW LETTERS LA English DT Article AB The first experimental observation of a strong millimeter wave radiation from a gyrating electron beam propagating through an H-plane bend rectangular folded waveguide is reported. Measurements of power, frequency, and relative phase change of both forward- and backward-wave radiations verified that the oscillation originated from an absolute instability near a stop band of the second space harmonic. A high power radiation of 5.5 kW which corresponds to an electronic efficiency of 24% was observed at 32.8 GHz. C1 SAIC,MCLEAN,VA 22102. NORTHROP GRUMMAN CORP,ROLLING MEADOWS,IL 60008. BK SYST INC,ROCKVILLE,MD 20850. OMEGA P INC,NEW HAVEN,CT 06520. RP Choi, JJ (reprint author), USN,RES LAB,VACUUM ELECT BRANCH,WASHINGTON,DC 20375, USA. RI Park, Gunsik/A-1415-2014 NR 12 TC 9 Z9 10 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 27 PY 1996 VL 76 IS 22 BP 4273 EP 4276 DI 10.1103/PhysRevLett.76.4273 PG 4 WC Physics, Multidisciplinary SC Physics GA UM245 UT WOS:A1996UM24500044 ER PT J AU Roland, CM Ngai, KL AF Roland, CM Ngai, KL TI Short time dynamics of glass-forming liquids - Reply SO JOURNAL OF CHEMICAL PHYSICS LA English DT Letter ID BULK AMORPHOUS POLYMERS; NEUTRON-SCATTERING; LIGHT-SCATTERING; ALPHA-RELAXATION; CONDUCTIVITY-RELAXATION; BETA-RELAXATION; TRANSITION; SIMULATION; MOTION RP Roland, CM (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 35 TC 4 Z9 4 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 22 PY 1996 VL 104 IS 20 BP 8171 EP 8172 DI 10.1063/1.471528 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UL125 UT WOS:A1996UL12500043 ER PT J AU Lin, HB Tonucci, RJ Campillo, AJ AF Lin, HB Tonucci, RJ Campillo, AJ TI Observation of two-dimensional photonic band behavior in the visible SO APPLIED PHYSICS LETTERS LA English DT Article ID ARRAY AB Nanochannel glasses, containing regular hexagonal closed packed arrays of parallel air cylinders with periods varying from 0.25 to 0.19 mu m, are shown to display photonic band-gap behavior throughout the visible that is consistent with previously published theory. Immersing the glasses in liquids of various refractive indices allowed observation of the buildup of the bands as a function of cylinder dielectric constant. RP Lin, HB (reprint author), USN,RES LAB,OPT PHYS BRANCH,CODE 5610,WASHINGTON,DC 20375, USA. NR 13 TC 58 Z9 59 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 20 PY 1996 VL 68 IS 21 BP 2927 EP 2929 DI 10.1063/1.116357 PG 3 WC Physics, Applied SC Physics GA UL632 UT WOS:A1996UL63200003 ER PT J AU Menon, ESK Dutta, I AF Menon, ESK Dutta, I TI Surface modification of chemically vapor deposited diamond for producing adherent thick and thin film metallizations for electronic packaging SO APPLIED PHYSICS LETTERS LA English DT Article AB In order to make chemically vapor deposited diamond (CVDD) substrates amenable to surface metallization without significant reduction in thermal conductivity, very thin alumina films were grown on diamond by vapor deposition of Al in oxygen atmosphere, followed by very low-temperature annealing in oxygen. A Cr interlayer initially deposited on CVDD prior to alumina deposition was found to lead to excellent adhesion between the substrate and the deposit. The alumina films were characterized by scanning and transmission electron microscopy as well as Auger electron spectroscopy. (C) 1996 American Institute of Physics. RP Menon, ESK (reprint author), USN,POSTGRAD SCH,DEPT MECH ENGN,MONTEREY,CA 93943, USA. NR 5 TC 4 Z9 4 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 20 PY 1996 VL 68 IS 21 BP 2951 EP 2952 DI 10.1063/1.116365 PG 2 WC Physics, Applied SC Physics GA UL632 UT WOS:A1996UL63200011 ER PT J AU Malin, JI Meyer, JR Felix, CL Lindle, JR Goldberg, L Hoffman, CA Bartoli, FJ Lin, CH Chang, PC Murry, SJ Yang, RQ Pei, SS AF Malin, JI Meyer, JR Felix, CL Lindle, JR Goldberg, L Hoffman, CA Bartoli, FJ Lin, CH Chang, PC Murry, SJ Yang, RQ Pei, SS TI Type II mid-infrared quantum well lasers SO APPLIED PHYSICS LETTERS LA English DT Article AB Pulsed, optically pumped four-constituent Type-II (InAs-Ga1-xInxSb-InAs-AlSb) quantum well lasers emitting at 3.9-4.1 mu m were observed to lase up to 285 K with a characteristic temperature T-0 of 35 K for 170 K less than or equal to T-op less than or equal to 270 K. A theoretical analysis predicts dramatic further improvements once the potential for suppressing Auger recombination is fully realized. (C) 1996 American Institute of Physics. C1 UNIV HOUSTON,CTR SPACE VACUUM EPITAXY,HOUSTON,TX 77204. RP Malin, JI (reprint author), USN,RES LAB,CODE 5600,WASHINGTON,DC 20375, USA. RI Lindle, James/A-9426-2009 NR 10 TC 62 Z9 63 U1 1 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 20 PY 1996 VL 68 IS 21 BP 2976 EP 2978 DI 10.1063/1.116374 PG 3 WC Physics, Applied SC Physics GA UL632 UT WOS:A1996UL63200020 ER PT J AU Hurley, K Li, P Vrba, F Luginbuhl, C Hartmann, D Kouveliotou, C Meegan, C Fishman, G Kulkarni, S Frail, D Bowyer, S Lampton, M AF Hurley, K Li, P Vrba, F Luginbuhl, C Hartmann, D Kouveliotou, C Meegan, C Fishman, G Kulkarni, S Frail, D Bowyer, S Lampton, M TI A possible x-ray counterpart to SGR 1900+14 SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma-rays, bursts; stars, neutron; supernova remnants AB The location of the soft gamma repeater SGR 1900+14 was recently reduced to two similar to 5 arcmin(2) alternate error boxes by the network synthesis method. We have used the ROSAT High Resolution Imager to observe the error box that is closest to the supernova remnant G42.8+0.6. A quiescent, steady, point X-ray source was found at alpha(2000) = 19(h)07(m)14(s).15, delta(2000) = 9 degrees 19'19 ''.06, whose unabsorbed flux is 3 x 10-(12) ergs cm(-2) s(-1). Its position is also consistent with a peculiar double infrared source described in a companion paper. We have also examined this region using the VLA,(1) and have obtained upper limits to the extreme ultraviolet flux of this object using the Extreme-Ultraviolet Explorer. C1 USN OBSERV,FLAGSTAFF,AZ 86002. CLEMSON UNIV,DEPT PHYS & ASTRON,CLEMSON,SC 29634. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. CALTECH,DEPT ASTRON,PASADENA,CA 91125. NATL RADIO ASTRON OBSERV,VLA,SOCORRO,NM 87801. UNIV CALIF BERKELEY,CTR EXTREME ULTRAVIOLET ASTROPHYS,BERKELEY,CA 94720. RP Hurley, K (reprint author), UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720, USA. NR 17 TC 28 Z9 28 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 20 PY 1996 VL 463 IS 1 BP L13 EP L16 DI 10.1086/310048 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UL341 UT WOS:A1996UL34100004 ER PT J AU Barth, CA Farmer, CB Siskind, DE Perich, JP AF Barth, CA Farmer, CB Siskind, DE Perich, JP TI ATMOS observations of nitric oxide in the mesosphere and lower thermosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERE; MIDDLE AB The nitric oxide density in the Earth's atmosphere between 50 and 130 km was measured by the ATMOS (Atmospheric Trace Molecule Spectroscopy) experiment onboard the Spacelab 3 mission on April 30, 1985 and May 1, 1985, Three observations were made at geographic latitudes of 35 degrees N, 34 degrees N, and 29 degrees N which correspond to geomagnetic latitudes of 26 degrees N, 44 degrees N, and 39 degrees N. The ATMOS measurements of nitric oxide in the thermosphere were compared to SME measurements made during the same time period. The two techniques agree within the geophysical variability of thermospheric nitric oxide. The observations show that during a geomagnetic storm there is a strong latitudinal gradient in the nitric oxide density in the lower thermosphere. Comparison of the observations with a one-dimensional time-dependent model shows that at midlatitudes, nitric oxide is transported downward from the thermosphere into the mesosphere as low as 70 km but not downward into the stratosphere. C1 CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. USN, RES LAB, EO HULBURT CTR SPACE RES, WASHINGTON, DC 20375 USA. UNIV COLORADO, DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI, BOULDER, CO 80309 USA. RP Barth, CA (reprint author), UNIV COLORADO, ATMOSPHER & SPACE PHYS LAB, CAMPUS BOX 590, BOULDER, CO 80309 USA. NR 20 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAY 20 PY 1996 VL 101 IS D7 BP 12489 EP 12494 DI 10.1029/96JD00553 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN558 UT WOS:A1996UN55800001 ER PT J AU Ho, T Wynne, KJ AF Ho, T Wynne, KJ TI A method to assess the average molecular weight for surface soft segments in poly[(dimethylsiloxane)-urea]s SO MACROMOLECULES LA English DT Article ID COPOLYMERS AB A gauge has been devised to measure the average molecular weight for surface soft segments in poly[(dimethylsiloxane)-urea]s. This quantity, M(s), is defined analogously to the number-average molecular weight, M(n). Information on the weight fraction of each segment at the surface, which can be measured by techniques such as electron spectroscopy for chemical analysis, is required for the calculation of M(s). The use of this quantity is illustrated by calculating the M(s) for a series of copolymers containing soft segments of broad molecular weight distribution. The limitation of this method with respect to the average molecular weight of the soft segments and Possible remedies are discussed. C1 VIRGINIA POLYTECH INST & STATE UNIV,DEPT CHEM,BLACKSBURG,VA 24061. OFF NAVAL RES,PHY SCI S&T DIV,ARLINGTON,VA 22217. USN,RES LAB,MAT CHEM BRANCH,WASHINGTON,DC 20375. NR 10 TC 2 Z9 2 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAY 20 PY 1996 VL 29 IS 11 BP 3991 EP 3995 DI 10.1021/ma9513022 PG 5 WC Polymer Science SC Polymer Science GA UM264 UT WOS:A1996UM26400044 ER PT J AU Drake, JC Allegra, CJ Moran, RG Johnston, PG AF Drake, JC Allegra, CJ Moran, RG Johnston, PG TI Resistance to Tomudex (ZD1694): Multifactorial in human breast and colon carcinoma cell lines SO BIOCHEMICAL PHARMACOLOGY LA English DT Article DE resistance; Tomudex; thymidylate synthase; folylpolyglutamate synthetase; colon cancer; breast cancer ID THYMIDYLATE SYNTHASE INHIBITOR; FOLYLPOLYGLUTAMATE SYNTHETASE; ACQUIRED-RESISTANCE; MEMBRANE-TRANSPORT; CCRF-CEM; ACID; SYSTEMS; CANCER; QUANTITATION; MECHANISMS AB ZD1694 (Tomudex; TDX) is a quinazoline antifolate that, when polyglutamated, is a potent inhibitor of thymidylate synthase (TS), the enzyme that converts dUMP to dTMP. Continuous exposure of MCF-7 breast and NCl H630 colon cells to TDX, with stepwise increases in TDX up to 2.0 mu M, resulted in stably resistant cell lines (MCF(TDX) and H630(TDX)) that were highly resistant to TDX. Initial studies revealed 34-fold increase in TS protein levels in MCF(TDX) and a 52-fold increase in TS levels in H630(TDX) cell lines. Despite continued exposure of these cells to 2.0 mu M TDX, TS protein and TS mRNA expression decreased to parental levels in H630(TDX) cells, whereas in MCF(TDX) cells TS mRNA expression and TS protein levels remained elevated. Southern blot analysis revealed a 20-fold TS gene amplification in the MCF(TDX) cell line. TDX uptake was 2-fold higher in resistant MCF(TDX) cells than in parental MCF-7 cells, whereas in H630(TDX) cells TDX uptake was 50-fold less than that observed in parental H630 cells. In contrast, no change in the transport of either leucovorin or methotrexate into H630(TDX) cells was noted when compared with the H630 parental cells. In H630(TDX) cells, folylpolyglutamate synthetase (FPGS) activity was 48-fold less compared to parent H630 cells; however, FPGS mRNA expression was similar in both lines. H630(TDX) cells were also highly resistant to ZD9331, a novel quinazoline TS inhibitor that does not require polyglutamation, suggesting that defective transport by the reduced folate carrier was also an important mechanism of resistance in these cells. In MCF(TDX) and H630(TDX) resistant cells, several mechanisms of resistance are apparent: one increased TS expression; the others evolved over time from increased TS expression to decreased FPGS levels and decreased TDX transport. C1 VIRGINIA COMMONWEALTH UNIV MED COLL VIRGINIA,MASSEY CANC CTR,RICHMOND,VA. RP Drake, JC (reprint author), USN HOSP,NCI,MED ONCOL BRANCH,8901 WISCONSIN AVE,BLDG 8,RM 5101,BETHESDA,MD 20889, USA. NR 27 TC 43 Z9 45 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0006-2952 J9 BIOCHEM PHARMACOL JI Biochem. Pharmacol. PD MAY 17 PY 1996 VL 51 IS 10 BP 1349 EP 1355 DI 10.1016/0006-2952(96)00057-3 PG 7 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA WC031 UT WOS:A1996WC03100013 PM 8787551 ER PT J AU Bitterwolf, TE Shade, JE Hansen, JA Rheingold, AL AF Bitterwolf, TE Shade, JE Hansen, JA Rheingold, AL TI Photoinduced rearrangements of ring-coupled bis(cyclopentadienylrutheniumdicarbonyl) compounds of the form Ru-2(CO)(4)(eta(5),eta(5)-C(5)H(4)LC(5)H(4)) (L=CH2-, (CH3)(2)C-, C2H4- and (CH3)(2)Si-) - The molecular structure of [Ru(CO)(2)][Ru(CO)(2)Cl](eta(5),eta(5):eta(1)-C5H4CH2C5H3) SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA English DT Article DE ruthenium; silicon; cyclopentadienyls; photochemistry; metal carbonyl ID LOW-TEMPERATURE; PHOTOCHEMISTRY; MATRICES; COMPLEXES; DINUCLEAR; DIMERS; IRON AB Compounds of the general form Ru-2(CO)(4)(eta(5),eta(5)-C(5)H(4)LC(5)H(4)), where L = CH2-, (CH3)(2)C-, C2H4- and (CH3)(2)Si-, have been found to undergo photolysis in deuterobenzene or deuterotoluene to give 'twisted' ruthenium hydride complexes of the form [Ru(CO)(2)][Ru(CO)(2)H](eta(5),eta(5):eta(1)-C(5)H(4)LC(5)H(3)). Reaction of these hydrides with chlorocarbons resulted in the formation of the corresponding chlorides which could be isolated and characterized by IR, H-1 and C-13 NMR, mass spectrometry, and elemental analysis. In the particular case of Ru-2(CO)(4)[eta(5),eta(5)-C5H4(CH3)(2)SiC5H4] a secondary photochemical reaction occurs with formation of [Ru(CO)(2)](2)(mu-eta(5):eta(1)-C5H4)[mu-(CH3)(2)Si-(eta(5)-C5H4)] in which Ru-Ru and Cp-Si bonds have been broken and new Ru-Cp and Ru-Si bonds formed. The molecular structure of [Ru(CO)(2)][RU(CO)(2)Cl](eta(5),eta(5):eta(1)-C5H4CH2C5H3) was determined by X-ray crystallography:monoclinic, Cc, a = 27.636(5) Angstrom, b = 9.058(2) Angstrom, c = 14.545(5) Angstrom, beta = 120.85(3)degrees, V = 3126(2) Angstrom(3), Z = 8, R(F)= 2.29%. C1 USN ACAD,DEPT CHEM,ANNAPOLIS,MD 21402. UNIV DELAWARE,DEPT CHEM & BIOCHEM,NEWARK,DE 19716. RP Bitterwolf, TE (reprint author), UNIV IDAHO,DEPT CHEM,MOSCOW,ID 83844, USA. NR 16 TC 32 Z9 32 U1 0 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-328X J9 J ORGANOMET CHEM JI J. Organomet. Chem. PD MAY 17 PY 1996 VL 514 IS 1-2 BP 13 EP 21 DI 10.1016/0022-328X(95)06018-R PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA UQ504 UT WOS:A1996UQ50400002 ER PT J AU Rolison, DR Bessel, CA Baker, MD Senaratne, C Zhang, J AF Rolison, DR Bessel, CA Baker, MD Senaratne, C Zhang, J TI Zeolite-modified electrodes: Intra- versus extrazeolite electron transfer - Reply SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID FAUJASITE-TYPE ZEOLITE; Y-MODIFIED ELECTRODES; ENCAPSULATED COMPLEXES; ELECTROCHEMISTRY C1 USN,RES LAB,SURFACE CHEM BRANCH,WASHINGTON,DC 20375. VILLANOVA UNIV,DEPT CHEM,VILLANOVA,PA 19085. RP Rolison, DR (reprint author), UNIV GUELPH,GUELPH WATERLOO CTR GRAD WORK CHEM,DEPT CHEM & BIOCHEM,GUELPH,ON N1G 2W1,CANADA. NR 23 TC 35 Z9 35 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 16 PY 1996 VL 100 IS 20 BP 8610 EP 8611 DI 10.1021/jp9607226 PG 2 WC Chemistry, Physical SC Chemistry GA UL282 UT WOS:A1996UL28200083 ER PT J AU Pearson, WH Shade, JE Brown, JE Bitterwolf, TE AF Pearson, WH Shade, JE Brown, JE Bitterwolf, TE TI Two monomeric ruthenium complexes containing bidentate bis(diphenylphosphino) ligands SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID CYCLOPENTADIENYL-OSMIUM CHEMISTRY; PHOSPHINES AB The crystal structures of chloro(eta(5)-cyclopentadienyl)-[methylenebis (diphenylphosphine-P)]ruthenium-chloroform (1/1), [RuCl(C5H5)(C25H22P2)].CHCl3, (A), and chloro(eta(5)-cyclopentadienyl)[1,2-ethanediylbis(diphenylphosphine-P)]ruthenium-chloroform (1/1), [RuCl(C5H5)(C26H24P2)].CHCl3, (B), are reported. Both complexes contain a central ring structure in which a pair of P atoms, linked by a -CH2- [in (A)] or a -C2H4- [in (B)] group, are bonded to a central Ru atom. The P-Ru-P bond angle undergoes expansion from 72.07 (2)degrees in (A) to 83.48(2)degrees in (B). The bond distances around the Ru center are compared with values reported for similar compounds. Both structures include a chloroform solvent molecule in addition to the ruthenium complex. The chloroform molecule in (A) was found to be disordered. C1 UNIV IDAHO,DEPT CHEM,MOSCOW,ID 83843. RP Pearson, WH (reprint author), USN ACAD,DEPT CHEM,ANNAPOLIS,MD 21402, USA. NR 11 TC 14 Z9 14 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD MAY 15 PY 1996 VL 52 BP 1106 EP 1110 DI 10.1107/S0108270195011802 PN 5 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA UP940 UT WOS:A1996UP94000020 ER PT J AU Wang, YJ Kaplan, R Ng, HK Doverspike, K Gaskill, DK Ikedo, T Akasaki, I Amono, H AF Wang, YJ Kaplan, R Ng, HK Doverspike, K Gaskill, DK Ikedo, T Akasaki, I Amono, H TI Magneto-optical studies of GaN and GaN/AlxGa1-xN: Donor Zeeman spectroscopy and two dimensional electron gas cyclotron resonance SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID HETEROJUNCTIONS AB Magneto-optical experiments have been performed on free and bound electrons in GaN films and GaN/AlGaN heterojunctions. Cyclotron resonance of two dimensional electron gas in GaN/AlxGa1-xN heterojunctions has yielded m* = 0.23 m(0), x-dependent scattering times consistent with values from transport measurements, and an apparent unexplained level crossing at 70 cm(-1). Infrared absorption of doped GaN films has shown that the binding energy of Si donors, 29.0 meV, is much smaller than that of residual donors, in agreement with transport measurements, thus suggesting donor spectroscopy as a useful technique for defect/impurity qualitative analysis. Zeeman effect of the donor spectra has been used to determine the GaN low frequency dielectric constant, epsilon(0) = 10.4. (C) 1996 American Institute of Physics. C1 USN,RES LAB,WASHINGTON,DC 20375. FLORIDA STATE UNIV,CTR MAT RES & TECHNOL,DEPT PHYS,TALLAHASSEE,FL 32306. MEIJO UNIV,DEPT ELECT & ELECTR ENGN,NAGOYA,AICHI 468,JAPAN. RP Wang, YJ (reprint author), FLORIDA STATE UNIV,NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32306, USA. NR 21 TC 97 Z9 99 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1996 VL 79 IS 10 BP 8007 EP 8010 DI 10.1063/1.362351 PG 4 WC Physics, Applied SC Physics GA UK226 UT WOS:A1996UK22600083 ER PT J AU Campbell, ML AF Campbell, ML TI Kinetic study of the reaction of Mn(a(6)S(5/2)) with N2O from 448 to 620 K SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID EXOTHERMIC HOMOLOGOUS REACTIONS; ACTIVATION BARRIERS; METAL ATOMS; SERIES AB The gas phase reactivity of Mn(a(6)S(5/2)) with N2O in the temperature range 448-620 K is reported. Manganese atoms were produced by the photodissociation of 2-methylcyclopentadienyl manganese tricarbonyl and detected by laser-induced fluorescence. The reaction rate of the a(6)S(5/2) state is very slow and temperature dependent. The rate constants are independent of total pressure indicating a bimolecular reaction. The rate constants are described in Arrhenius form by (2.05+/-0.45)x10(-10) exp(-44.7+/-1.0 kT/mol/RT) cm(3) s(-1). (C) 1996 American Institute of Physics. RP Campbell, ML (reprint author), USN ACAD,DEPT CHEM,ANNAPOLIS,MD 21402, USA. NR 17 TC 31 Z9 31 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 15 PY 1996 VL 104 IS 19 BP 7515 EP 7517 DI 10.1063/1.471654 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UK935 UT WOS:A1996UK93500013 ER PT J AU Thornton, EB Humiston, RT Birkemeier, W AF Thornton, EB Humiston, RT Birkemeier, W TI Bar/trough generation on a natural beach SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID LONGSHORE-CURRENT; SEDIMENT TRANSPORT; WAVES; MODEL AB Mechanisms for bar/trough generation are examined using velocities measured in the field applied to the Bowen [1980]/Bailard [1981] energetics-based sediment transport model. Measurements consist of a cross-shore array of nine electromagnetic current meters spanning the surf zone and daily bathymetric surveys during a IO-day period during which two storms occurred, when the bathymetry evolved from a three-dimensional terrace to a well-developed linear bar. The model predicts bed and suspended load transport separately based on various velocity moments. The velocities are partitioned into mean currents, low-frequency infragravity and shear instabilities (<0.05 Hz), and high-frequency short waves and turbulence (>0.05 Wt) to determine the relative importance of various mechanisms to the total transport. Velocity moments are computed over 90-min intervals to resolve tidal fluctuations. Tidal signatures were apparent in all modes of transport. Predicted transport rates are integrated and compared with daily cross-shore bathymetric profiles (averaged over a 400-m length of beach). The suspended load terms were an order of magnitude greater than bed load terms owing to the low fall velocity of the fine-grain sand within the surf zone. Model results for this experiment indicate the dominant mechanism for bar development was sediments mobilized by the strong longshore current and incident short waves within the surf zone and transported offshore by the mean undertow and shoreward transport onshore due to short wave velocity skewness. Using standard coefficients, the model correctly predicted the first-order movement of the bar during storms, but underpredicted trough development, and did not always perform well during mild wave conditions. C1 USN, PACIFIC METEOROL & OCEANOG CTR, HONOLULU, HI 96860 USA. USA, CORPS ENGINEERS, FIELD RES FACIL, KITTY HAWKS, NC 27949 USA. RP Thornton, EB (reprint author), USN, POSTGRAD SCH, DEPT OCEANOG, MONTEREY, CA 93943 USA. NR 34 TC 117 Z9 117 U1 1 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAY 15 PY 1996 VL 101 IS C5 BP 12097 EP 12110 DI 10.1029/96JC00209 PG 14 WC Oceanography SC Oceanography GA UL258 UT WOS:A1996UL25800018 ER PT J AU Metzger, EJ Hurlburt, HE AF Metzger, EJ Hurlburt, HE TI Coupled dynamics of the South China Sea, the Sulu Sea, and the Pacific Ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID WORLD OCEAN; CIRCULATION; MODEL; INTRUSION; WATER AB The complex geometry, the seasonally reversing monsoon winds, and the connectivity with the Pacific Ocean all contribute to the coupled dynamics of the circulation in the South China Sea (SCS), the Sulu Sea, and the region around the Philippine Islands. The 1/2 degrees, 1.5-layer global reduced gravity thermodynamic Navy layered ocean model (NLOM) is used to separate these components and to investigate the role of each one. When forced by the Hellerman and Rosenstein [1983] (HR) monthly wind stress climatology, the basic features of the model solution compare well with observations, and with higher-resolution NLOM versions. The dynamics of the flow from the Pacific Ocean into the SCS via the Luzon Strait are emphasized. The effects of Ekman suction/pumping due to wind curl are examined by forming monthly spatial averages of the winds over the SCS/Sulu Sea basins. This maintains a monthly varying stress but with a region of zero curl. Forcing the model with these modified winds leaves the mean Luzon Strait transport unchanged, and the variability actually increases slightly. These results suggest that it is the pressure head created by the pileup of water from the monsoonal wind stress that controls the variability of the Luzon Strait transport. The forcing for wind stress pileup effects could be either internal or external to the SCS/Sulu Sea basin. The effects of internal forcing are studied by applying monthly winds within this basin but annual HR winds outside the region. With this forcing the mean Luzon Strait transport is essentially unchanged, but the variability is only 44% of the standard case value. The external forcing is defined as zero stress in the SCS/Sulu Sea basins and HR monthly winds outside. Again, the mean Luzon Strait transport is unchanged, and here the variability is 60% of the standard case. The mean Luzon Strait transport is largely a function of the model geometry. When the Sulu archipelago is opened, a net cyclonic flow develops around the Philippines, which is essentially an extension of the northern tropical gyre. The bifurcation latitude of the North Equatorial Current (NEC) at the Philippine coast is also affected by the amount of transport through the Sulu archipelago. Opening this archipelago causes the NEC split point to move southward and increases the transport of the Kuroshio east of Luzon while decreasing the Mindanao Current. Opening or closing the Sunda Shelf/Java Sea or the Sulu archipelago does not affect the transport of the Pacific to Indian Ocean throughflow. RP Metzger, EJ (reprint author), USN, CODE 7323, BAY ST LOUIS, MS 39529 USA. NR 36 TC 234 Z9 276 U1 6 U2 24 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAY 15 PY 1996 VL 101 IS C5 BP 12331 EP 12352 DI 10.1029/95JC03861 PG 22 WC Oceanography SC Oceanography GA UL258 UT WOS:A1996UL25800035 ER PT J AU Hickey, TE Blair, PJ Perfetto, S Smoot, DS Wagner, KF StLouis, DC Mayers, DL Siegel, JN June, CH AF Hickey, TE Blair, PJ Perfetto, S Smoot, DS Wagner, KF StLouis, DC Mayers, DL Siegel, JN June, CH TI Intact antigen receptor-mediated calcium signals in patients with early stage HIV-1 infection SO JOURNAL OF IMMUNOLOGY LA English DT Article ID HUMAN-IMMUNODEFICIENCY-VIRUS; T-CELL ACTIVATION; TYROSINE KINASE P56LCK; LYMPHOCYTES-T; CD4; GP120; PERTURBATION; PHOSPHORYLATION; TRANSDUCTION; MOBILIZATION AB A variety of deficiencies in T cell activation have been described in HIV-1 infection. To determine whether one component of Ag receptor signal transduction might be impaired and contribute to the immunopathology of HIV infection, we tested CD4 cells from patients with early to mid-stage HIV infection for TCR-induced calcium mobilization. There was no detectable difference between patients and controls in the mean CD4 cell calcium response or in the fraction of responding CD4 cells after crosslinking the TCR with OKT3 Ab. in addition, in HIV-infected patients, there was no correlation between calcium mobilization and the CD4 cell count. These results indicate that there are no intrinsic impairments of Ag receptor calcium signaling in circulating CD4 cells from HIV-infected patients with >400 CD4 cells/mm(3), although abnormalities in patients with later stage infections cannot be excluded. C1 USN,MED RES INST,IMMUNE CELL BIOL PROGRAM,TISSUE BANK,BETHESDA,MD 20889. HENRY M JACKSON FDN ADVANCEMENT MIL MED,ROCKVILLE,MD 20852. WALTER REED ARMY MED CTR,WALTER REED ARMY INST RES,WASHINGTON,DC 20307. UNIFORMED SERV UNIV HLTH SCI,DEPT MED,BETHESDA,MD 20814. FU NIAID NIH HHS [AI 22931] NR 44 TC 7 Z9 7 U1 0 U2 0 PU AMER ASSOC IMMUNOLOGISTS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0022-1767 J9 J IMMUNOL JI J. Immunol. PD MAY 15 PY 1996 VL 156 IS 10 BP 4012 EP 4017 PG 6 WC Immunology SC Immunology GA UJ341 UT WOS:A1996UJ34100055 PM 8621943 ER PT J AU Ethridge, EC Erwin, SC Pickett, WE AF Ethridge, EC Erwin, SC Pickett, WE TI Nb4N3: Polymorphism in crystalline niobium nitrides SO PHYSICAL REVIEW B LA English DT Article ID DENSITY AB Local-density-based electronic structure methods are applied to gamma-NbN (tetragonal Nb4N3) to compare it to the strong-coupling superconductor NbN (rocksalt structure) and to the recently proposed Pm3m NbN phase, (NbO structure) which has a similar transition temperature. In certain respects gamma-NbN is intermediate between the other phases, as might be expected, but overall the electronic spectrum more closely resembles rocksalt NbN. The N ion in gamma-NbN is more highly charged (N-1) than in the other two phases. RP Ethridge, EC (reprint author), USN,RES LAB,COMPLEX SYST THEORY BRANCH,WASHINGTON,DC 20375, USA. RI Erwin, Steven/B-1850-2009 NR 14 TC 5 Z9 5 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD MAY 15 PY 1996 VL 53 IS 19 BP 12563 EP 12565 DI 10.1103/PhysRevB.53.12563 PG 3 WC Physics, Condensed Matter SC Physics GA UM478 UT WOS:A1996UM47800008 ER PT J AU Simon, DI Mullins, ME Jia, L Gaston, B Singel, DJ Stamler, JS AF Simon, DI Mullins, ME Jia, L Gaston, B Singel, DJ Stamler, JS TI Polynitrosylated proteins: Characterization, bioactivity, and functional consequences SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID BOVINE SERUM-ALBUMIN; NITRIC-OXIDE; S-NITROSOTHIOLS; RELAXING FACTOR; ANTIPLATELET PROPERTIES; INHIBITION; NITROSYLATION; NITROSATION; MECHANISM; CYSTEINE AB Chemical modification of proteins is a common theme in their regulation. Nitrosylation of protein sulfhydryl groups has been shown to confer nitric oxide (NO)-like biological activities and to regulate protein functions. Several other nucleophilic side chains-including those with hydroxyls, amines, and aromatic carbons-are also potentially susceptible to nitrosative attack. Therefore, we examined the reactivity and functional consequences of nitros(yl)ation at a variety of nucleophilic centers in biological molecules. Chemical analysis and spectroscopic studies show that nitrosation reactions are sustained at sulfur, oxygen, nitrogen, and aromatic carbon centers. with thiols being the most reactive functionality. The exemplary protein, BSA, in the presence of a 1-, 20-, 100-, or 200-fold excess of nitrosating equivalents removes 0.6 +/- 0.2, 3.2 +/- 0.4, 18 +/- 4, and 38 +/- 10, respectively, moles of NO equivalents per mole of BSA from the reaction medium; spectroscopic evidence shows the proportionate formation of a polynitrosylated protein. Analogous reaction of tissue-type plasminogen activator yields comparable NO/protein stoichiometries. Disruption of protein tertiary structure by reduction results in the preferential nitrosylation of up to 20 thus-exposed thiol groups. The polynitrosylated proteins exhibit antiplatelet and vasodilator activity that increases with the degree of nitrosation, but S-nitroso derivatives show the greatest NO-related bioactivity. Studies on enzymatic activity of tissue-type plasminogen activator show that poly-nitrosylation may lead to attenuated function. Moreover, the reactivity of tyrosine residues in proteins raises the possibility that NO could disrupt processes regulated by phosphorylation. Polynitrosylated proteins were found in reaction mixtures containing interferon-gamma/lipopolysaccharide-stimulated macrophages and in tracheal secretions of subjects treated with NO gas, thus suggesting their physiological relevance. In conclusion, multiple sites on proteins are susceptible to attack by nitrogen oxides, Thiol groups are preferentially modified, supporting the notion that S-nitrosylation can serve to regulate protein function. Nitrosation reactions sustained at additional nucleophilic centers may have (patho)physiological significance and suggest a facile route by which abundant NO bioactivity can be delivered to a biological system, with specificity dictated by protein substrate. C1 DUKE UNIV,MED CTR,DEPT MED,DIV PULM,DURHAM,NC 27710. DUKE UNIV,MED CTR,DEPT MED,DIV CARDIOVASC,DURHAM,NC 27710. BRIGHAM & WOMENS HOSP,DEPT MED,DIV CARDIOVASC,BOSTON,MA 02115. HARVARD UNIV,DEPT CHEM,CAMBRIDGE,MA 02138. USN HOSP,DEPT PEDIAT,SAN DIEGO,CA 92134. MONTANA STATE UNIV,DEPT CHEM & BIOCHEM,BOZEMAN,MT 59717. FU NHLBI NIH HHS [HL02768, HL52529, HL02582] NR 38 TC 172 Z9 173 U1 1 U2 11 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD MAY 14 PY 1996 VL 93 IS 10 BP 4736 EP 4741 DI 10.1073/pnas.93.10.4736 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UL255 UT WOS:A1996UL25500041 PM 8643472 ER PT J AU Jensen, KL Phillips, PM Nguyen, K Malsawma, L Hor, C AF Jensen, KL Phillips, PM Nguyen, K Malsawma, L Hor, C TI Electron emission from a single Spindt-type field emitter structure: Correlation of theory and experiment SO APPLIED PHYSICS LETTERS LA English DT Article AB The performance characteristics of rf power amplifiers will be significantly enhanced if a cathode source capable of producing current densities greater than 10 A/cm(2) under gigahertz modulation can be created. Characterization of single- and multiple-tip arrays is imperative to determine performance characteristics in order to design and implement inductive output amplifiers (IOA): knowledge of the beam spread is paramount in the design of the helix or cavity power extraction region. Nevertheless, a simple analytic model for gated field emitters for understanding the spatial dispersion of the emitted electrons has not emerged. We provide such a model, approximating the tip by a smooth sphere and the gate by a ring of charge (Saturn model), and correlate it with experimental measurements made on a single Spindt-type molybdenum field emitter using a nanofabricated anode whose position from the emitter was determined using laser interferometry. Methods used to correlate theory with experiment are explained, and the dependence of the beam profile on tip sharpness, gate diameter, anode distance, and tip work function are examined. There is good agreement between theory and experiment. Measurement has shown that the rms spread angle is between 15 degrees and 29 degrees. RP Jensen, KL (reprint author), USN,RES LAB,DIV ELECTR SCI & TECHNOL,CODE 6840,WASHINGTON,DC 20357, USA. RI Jensen, Kevin/I-1269-2015 OI Jensen, Kevin/0000-0001-8644-1680 NR 9 TC 5 Z9 5 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 13 PY 1996 VL 68 IS 20 BP 2807 EP 2809 DI 10.1063/1.116331 PG 3 WC Physics, Applied SC Physics GA UK569 UT WOS:A1996UK56900012 ER PT J AU Rajagopal, AK AF Rajagopal, AK TI Von Neumann and Tsallis entropies associated with the Gentile interpolative quantum statistics SO PHYSICS LETTERS A LA English DT Article AB We obtain the von Neumann entropy per state of the Gentile interpolative statistics in terms of the mean occupation number (n) over bar, as S-G = -{(n) over bar In omega + In[(1 - omega)/(1 - omega(d+1))]}, where omega is obtained by solving the equation (n) over bar = omega/(1 + omega) - (d + 1)omega(d+1)/(1 - omega(d+1)). These go over to the familiar expressions for the cases of Fermi (d = 1) and Bose (d = infinity) statistics. The second order fluctuation from the mean is found to be mu(2) = R[omega/(1 - omega)2 - (d + 1)(2) omega(d+1)/(1 - omega(d+1))(2)]. For nonextensive systems, corresponding results are also derived by employing the T sallis entropy which includes the von Neumann entropy valid for extensive systems only. A discussion of these with the other interpolative statistics of Haldane is also given. RP Rajagopal, AK (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 21 TC 10 Z9 10 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD MAY 13 PY 1996 VL 214 IS 3-4 BP 127 EP 130 DI 10.1016/0375-9601(96)00177-6 PG 4 WC Physics, Multidisciplinary SC Physics GA UL714 UT WOS:A1996UL71400004 ER PT J AU Najita, J Carr, JS Shu, FH Tokunaga, AT AF Najita, J Carr, JS Shu, FH Tokunaga, AT TI Kinematic diagnostics of disks around young stars: CO overtone emission from WL 16 and 1548C27 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; circumstellar matter; infrared, stars; stars, individual (1548C27, WL16); stars, pre-main-sequence ID INTERMEDIATE-MASS STARS; STELLAR OBJECT WL-16; HERBIG AE/BE STARS; T-TAURI STARS; ACCRETION DISKS; ROTATIONAL-EXCITATION; INFRARED OBSERVATIONS; CIRCUMSTELLAR DISKS; COMETARY NEBULA; LINE-PROFILES AB We report high spectral resolution observations of the CO vibrational overtone emission from the young stellar object 1548C27; our observations include both the v = 2-0 and v = 5-3 band head regions. These data and similar observations of the young stellar object WL 16, reported in a previous contribution to this journal, provide some of the most compelling evidence to date for the existence of inner disks around young stars. We describe the simple procedure that we use to synthesize band head emission from disks including the effect of thermal dissociation of CO and non-LTE excitation of the vibrational levels. Using this spectral synthesis procedure to extract the kinematics and physical properties of the emitting gas from the overtone data, we show how these high signal-to-noise ratio data are also powerful probes of the stellar and inner disk. properties of these systems. Our modeling is consistent with the identification of WL 16 and 1548C27 as Herbig AeBe stars with stellar masses of approximately 2 and 4 M(circle dot), respectively. Thus, the kinematic signature of rotating disks in the overtone spectra of these sources provides strong support for the role of accretion disks in the formation of intermediate-mass stars. For both WL 16 and 1548C27, we interpret our modeling results as indicating that the overtone emission arises from a temperature inversion region in the inner disk atmosphere. We also find evidence for suprathermally broadened lines and are able to place useful constraints on the radial temperature and column density distributions of the CO line formation region of the disk atmosphere. Given these deduced properties, we discuss the constraints that our observations place on the physical processes responsible for the overtone emission in these sources. C1 UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720. USN,RES LAB,REMOTE SENSING DIV,WASHINGTON,DC 20375. NYU,DEPT PHYS,NEW YORK,NY 10003. UNIV HAWAII,INST ASTRON,HONOLULU,HI 96822. NR 77 TC 106 Z9 106 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 1996 VL 462 IS 2 BP 919 EP 936 DI 10.1086/177205 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UH187 UT WOS:A1996UH18700033 ER PT J AU Laming, JM Drake, JJ Widing, KG AF Laming, JM Drake, JJ Widing, KG TI Stellar coronal abundances .4. Evidence of the FIP effect in the corona of epsilon Eridani? SO ASTROPHYSICAL JOURNAL LA English DT Article DE line, identification; stars, coronae; stars, individual (epsilon Eridani); ultraviolet, stars ID MAIN-SEQUENCE STARS; SOLAR-FLARES; FE-XIV; LINE RATIOS; TRANSITION-PROBABILITIES; ELEMENTAL ABUNDANCES; ACTIVE REGIONS; ENERGY-LEVELS; ATOMIC DATA; CA-XVII AB We present an analysis of the EUV spectrum of the chromospherically active star epsilon Eridani (K2 V) recorded by the Extreme-Ultraviolet Explorer satellite. We have identified many lines from different elements (O, Ne, Mg, Si, S, Ar, Ca, Fe, and Ni) with first ionization potential (FIP) above and below about 10 eV (high and low FIP, respectively) and have used the measured relative intensities of these to investigate the emission measure (EM) distribution and the coronal element abundances. The spectrum of epsilon Eri reveals much hotter plasma than the quiet Sun and, as such, is interesting to compare with EUV spectra of solar flares. The EM distribution is found to be sharply peaked near log T = 6.5. The data suggest that a solar-like FIP effect is in operation, although the limited number of high-FIP lines detected, together with the sharply peaked shape of the EM distribution and low signal-to-noise ratio of the spectra, preclude a definitive judgement. However, we can conclude that there cannot be an enhancement of low-FIP species in the corona of epsilon Eri significantly larger than that seen in the ''average'' solar corona, which may imply that the magnitude of the FIP effect does not seem to increase with increasing stellar activity, but this should be confirmed by other cases. C1 USN,RES LAB,WASHINGTON,DC 20375. UNIV CALIF BERKELEY,CTR EUV ASTROPHYS,BERKELEY,CA 94720. USN,RES LAB,EO HULBURT CTR SPACE RES,WASHINGTON,DC 20375. RP Laming, JM (reprint author), SFA INC,LANDOVER,MD 20785, USA. NR 78 TC 52 Z9 52 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 1996 VL 462 IS 2 BP 948 EP 959 DI 10.1086/177208 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UH187 UT WOS:A1996UH18700036 ER PT J AU Spadaro, D Lanza, AF Antiochos, SK AF Spadaro, D Lanza, AF Antiochos, SK TI A study of the unresolved fine-structure model for the solar transition region SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun, transition region; Sun, UV radiation ID EXTREME-ULTRAVIOLET; EMISSION-LINES; FLUID MOTIONS; TEMPERATURE REGION; ACTIVE REGIONS; QUIET SUN; ATMOSPHERE; SPICULES; SPECTRUM; CHROMOSPHERE AB The unresolved fine-structure (UFS) model for the lower transition region was proposed by Feldman as an explanation for a number of puzzling observational results: specifically, the small filling factor of this region, the inability of the observations to resolve the temperature structure, and the observation of persistent redshifted UV emission lines even near the solar limb. It was hypothesized that opacity effects may be able to explain the redshift observations. We consider a simple model for the UFS consisting of a plasma sphere undergoing expansion and contraction due to a time-varying heating. We calculate in detail the line profile of the well-observed C IV 1548 Angstrom line. Our calculations include the effects of both nonequilibrium ionization and radiative transfer. We find that although the model can reproduce some of the features of the observations, such as the line widths, the effect of finite optical depth is to produce a blueshifted peak for the emission line, contrary to observations. The physical origins of this blueshift are discussed. We conclude that unless the pressures of the UFS are significantly higher than the typical pressures assumed for the lower transition region, opacity effects are unlikely to explain the observations. C1 USN,RES LAB,EO HULBURT CTR SPACE RES,WASHINGTON,DC 20375. RP Spadaro, D (reprint author), OSSERV ASTROFIS CATANIA,CITTA UNIV,I-95125 CATANIA,ITALY. RI Antiochos, Spiro/D-4668-2012 OI Antiochos, Spiro/0000-0003-0176-4312 NR 56 TC 12 Z9 12 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 10 PY 1996 VL 462 IS 2 BP 1011 EP 1019 DI 10.1086/177215 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UH187 UT WOS:A1996UH18700043 ER PT J AU Yamada, K Rice, KC FlippenAnderson, JL Eissenstat, MA Ward, SJ Johnson, MR Howlett, AC AF Yamada, K Rice, KC FlippenAnderson, JL Eissenstat, MA Ward, SJ Johnson, MR Howlett, AC TI (Aminoalkyl)indole isothiocyanates as potential electrophilic affinity ligands for the brain cannabinoid receptor SO JOURNAL OF MEDICINAL CHEMISTRY LA English DT Article ID ANALOGS; PRAVADOLINE; BINDING AB A series of (aminoalkyl)indole compounds, naphthalene analogs of pravadoline (1), has been shown to exhibit cannabinoid agonist activities such as antinociception in animals, inhibition of adenylate cyclase in brain membranes, and binding to the cannabinoid receptor. These pravadoline analogs were selected for the preparation of potential electrophilic affinity ligands based on the synthesis of isothiocyanate derivatives. One isothiocyanatonaphthalene derivative (8) displaced [H-3]CP-55940 binding to a rat brain P2 membrane preparation with an IC50 of 690 nM, which was 10-fold less potent than the parent molecule (IC50 = 73 nM). Isothiocyanate substitution at various positions on the naphthalene moiety of the desmethyl analog 10 gave compounds that displaced [H-3]CP-55940 with IC50 values between 400 and 1000 nM, compared with 46 nM for the parent compound 10. However, 6-isothiocyanato substitution on the indole ring of the desmethyl analog provided isothiocyanate 12 that displaced [H-3]CP-55940 binding with an IC50 of 160 nM. After pretreatment of brain membranes with this high-affinity isothiocyanato ligand followed by washing out the ligand, the membranes were depleted of 90% of the cannabinoid receptor binding capacity. Loss of receptor binding capacity was half-maximal at 300 nM of the derivative under standard assay conditions. As a control, pretreatment with the parent compound at concentrations that were 20 times the K-d failed to alter subsequent binding activity. This study demonstrates that an isothiocyanato (aminoalkyl)-indole (12) can behave as an affinity ligand which binds irreversibly to the cannabinoid receptor in brain and which precludes subsequent binding of the cannabinoid ligand [H-3]CP-55940. C1 ST LOUIS UNIV,SCH MED,DEPT PHARMACOL & PHYSIOL SCI,ST LOUIS,MO 63104. NIDDKD,MED CHEM LAB,BETHESDA,MD 20892. USN,RES LAB,STRUCT MATTER LAB,WASHINGTON,DC 20375. SANOFI WINTHROP,SANOFI RES DIV,DEPT MED CHEM,COLLEGEVILLE,PA 19426. TRIMERIS,RES TRIANGLE PK,NC 27709. OI Ward, Susan J/0000-0002-5729-5263; Howlett, Allyn/0000-0002-2810-0164 FU NIDA NIH HHS [R01-DA06312, K05-DA00182] NR 27 TC 12 Z9 12 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-2623 J9 J MED CHEM JI J. Med. Chem. PD MAY 10 PY 1996 VL 39 IS 10 BP 1967 EP 1974 DI 10.1021/jm950932r PG 8 WC Chemistry, Medicinal SC Pharmacology & Pharmacy GA UM248 UT WOS:A1996UM24800008 PM 8642555 ER PT J AU Bertha, CM Ellis, M FlippenAnderson, JL Porreca, F Rothman, RB Davis, P Xu, H Becketts, K Rice, KC AF Bertha, CM Ellis, M FlippenAnderson, JL Porreca, F Rothman, RB Davis, P Xu, H Becketts, K Rice, KC TI Probes for narcotic receptor-mediated phenomena .21. Novel derivatives of 3-(1,2,3,4,5,11-hexahydro-3-methyl-2,6-methano-6H-azocino[4,5-b]indol-6- yl)-phenols with improved delta opioid receptor selectivity SO JOURNAL OF MEDICINAL CHEMISTRY LA English DT Article ID BINDING-SITES; AFFINITY; AGONIST; PEPTIDES; BW373U86; ANALOG; BRAIN AB Derivatives of racemic and optically pure levorotatory 3-(1,2,3,4,5,11-hexahydro-3-methyl-2,6-methano-6H-azocino[4,5-b] indol-6-yl)phenols containing methoxy substituents in the C10', C9', and C8' positions (compounds 9-11, respectively) were synthesized and characterized by spectroscopic and X-ray methods. The binding affinities for the mu, delta, and kappa(1) opioid receptors and activity in the guinea pig ileum (GPI) and mouse vas deferens (MVD) functional bioassays were determined for these compounds. A methoxy substituent in the C8' position decreases the binding affinity for both the mu and delta receptors, while a C10' methoxy substituent has little effect on either binding affinity. Interestingly, a methoxy group at the C9' position in the levorotatory series provides compound (-)-10 which exhibits both enhanced in vitro affinity and selectivity for the delta opioid receptor relative to the unsubstituted derivative (-)-8 and is the most selective (mu/delta IC50 ratio 17.9, kappa(1)/delta IC50 ratio 314) and highest affinity (IC50 3.7 nM) delta receptor ligand for this novel class of compounds. The results of the GPI and MVD bioassays are more dramatic and indicate that (-)-10 is an agonist for the delta receptor (IC50 49.0 nM) with substantial selectivity for the delta versus the mu receptor borne out by a GPI/MVD IC50 ratio of >612. C1 NIDDKD,MED CHEM LAB,NIH,BETHESDA,MD 20892. USN,RES LAB,STRUCT MATTER LAB,WASHINGTON,DC 20375. NIDA,ADDICT RES CTR,CLIN PSYCHOPHARMACOL SECT,BALTIMORE,MD 21224. UNIV ARIZONA,ARIZONA HLTH SCI CTR,DEPT PHARMACOL,TUCSON,AZ 85724. NR 24 TC 10 Z9 10 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-2623 J9 J MED CHEM JI J. Med. Chem. PD MAY 10 PY 1996 VL 39 IS 10 BP 2081 EP 2086 DI 10.1021/jm950695s PG 6 WC Chemistry, Medicinal SC Pharmacology & Pharmacy GA UM248 UT WOS:A1996UM24800020 PM 8642567 ER PT J AU Rappoli, BJ DeSisto, WJ AF Rappoli, BJ DeSisto, WJ TI Gas phase ultraviolet spectroscopy of high-temperature superconductor precursors for chemical vapor deposition processing SO APPLIED PHYSICS LETTERS LA English DT Article ID YBA2CU3O7-X THIN-FILMS; REACTOR; BA; COMPLEXES; PRESSURES; MOVPE AB UV spectroscopy has been used as an in situ diagnostic to measure the gas phase concentration of 2,2,6,6-tetramethyl-3,5-heptanedionate (thd) complexes of Cu and Y in metalorganic chemical vapor deposition (MOCVD) bubbler effluent. These Cu and Y precursors for MOCVD synthesis of YBa2Cu3O7-delta (YBCO) show marked instability in gas phase concentration as a function of time during the initial bubbler purge. The precursors show ideal behavior as predicted by the Clausius-Clapeyron relation. The UV diagonstic technique has the potential of controlling precursor concentration for MOCVD fabrication of high-temperature superconducting thin films. C1 USN,RES LAB,DIV ELECTR SCI & TECHNOL,WASHINGTON,DC 20375. RP Rappoli, BJ (reprint author), USN,RES LAB,DIV CHEM,WASHINGTON,DC 20375, USA. NR 26 TC 16 Z9 16 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 6 PY 1996 VL 68 IS 19 BP 2726 EP 2728 DI 10.1063/1.115578 PG 3 WC Physics, Applied SC Physics GA UJ089 UT WOS:A1996UJ08900042 ER PT J AU Qadri, SB Osofsky, MS Browning, VM Skelton, EF AF Qadri, SB Osofsky, MS Browning, VM Skelton, EF TI High resolution characterization of structural inhomogeneities in YBa2Cu3O7-delta crystals with sharp superconducting transitions SO APPLIED PHYSICS LETTERS LA English DT Article ID SINGLE-CRYSTALS; OXYGEN; GRANULARITY; PLATEAUS; 60-K AB Structural inhomogeneities in two single crystals of YBa2Cu3O7-delta are characterized using high resolution x-ray diffraction. Results of these analyses show a distribution in the c-axis lattice parameters. These are interpreted as evidence of a distribution in oxygen content. Values of 7-delta range from 6.71 to 7.00 in one crystal and from 6.80 to 6.99 in the other. Nevertheless, the measured superconducting transition widths for both crystals are less than 0.5 K, as determined by ac susceptibility. When examined with conventional x-ray diffraction techniques, both crystals also appeared to be free of gross defects, but high resolution rocking curves reveal variations in defect density. These results suggest that crystals presumed to be homogeneous based on narrow superconducting transition widths or conventional x-ray diffractometry, may not be. Therefore, crystals found to exhibit exotic physical properties should be carefully examined for the presence of structural anomalies. If such defects are present, the experimental results may be attributed to sample imperfections, rather than intrinsic phenomena. RP Qadri, SB (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Osofsky, Michael/A-1050-2010 NR 28 TC 14 Z9 14 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 6 PY 1996 VL 68 IS 19 BP 2729 EP 2731 DI 10.1063/1.115579 PG 3 WC Physics, Applied SC Physics GA UJ089 UT WOS:A1996UJ08900043 ER PT J AU Sundar, RA Keller, TM AF Sundar, RA Keller, TM TI Synthesis and characterization of linear boron-silicon-diacetylene copolymers SO MACROMOLECULES LA English DT Article ID POLYMERS C1 USN,RES LAB,DIV CHEM,MAT CHEM BRANCH,WASHINGTON,DC 20375. NR 25 TC 17 Z9 17 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAY 6 PY 1996 VL 29 IS 10 BP 3647 EP 3650 DI 10.1021/ma951476j PG 4 WC Polymer Science SC Polymer Science GA UK468 UT WOS:A1996UK46800049 ER PT J AU Santangelo, PG Ngai, KL Roland, CM AF Santangelo, PG Ngai, KL Roland, CM TI Temperature dependence of relaxation in polypropylene and poly(ethylene-co-propylene) SO MACROMOLECULES LA English DT Article ID DYNAMIC LIGHT-SCATTERING; SEGMENTAL RELAXATION; INTERMOLECULAR COOPERATIVITY; DIELECTRIC-RELAXATION; AMORPHOUS POLYMERS; VISCOELASTIC PROPERTIES; TRANSITION REGION; GLASS-TRANSITION; POLYISOPRENE; BEHAVIOR C1 USN,RES LAB,DIV CHEM,WASHINGTON,DC 20375. NR 38 TC 56 Z9 56 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAY 6 PY 1996 VL 29 IS 10 BP 3651 EP 3653 DI 10.1021/ma951531o PG 3 WC Polymer Science SC Polymer Science GA UK468 UT WOS:A1996UK46800050 ER PT J AU Rajagopal, AK AF Rajagopal, AK TI Dynamic linear response theory for a nonextensive system based on the Tsallis prescription SO PHYSICAL REVIEW LETTERS LA English DT Article AB We develop here a dynamic linear response theory of many-body nonextensive systems based on the maximization of the Tsallis entropy associated with the density matrix and the concomitant suitably defined mean total energy, number, etc., where the averaging is over the qth power of the density matrix, q being a parameter characterizing the nonextensivity. This formulation is shown to preserve causality (Kramers-Kronig), time reversal, and Onsager reciprocity, while a different form of fluctuation-dissipation theorem is obtained. The traditional theory for extensive systems is obtained in the special case where q = 1. RP Rajagopal, AK (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 29 TC 112 Z9 112 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 6 PY 1996 VL 76 IS 19 BP 3469 EP 3473 DI 10.1103/PhysRevLett.76.3469 PG 5 WC Physics, Multidisciplinary SC Physics GA UW490 UT WOS:A1996UW49000001 ER PT J AU Nounesis, G Ratna, BR Shin, S Flugel, RS Sprunt, SN Singh, A Litster, JD Shashidhar, R Kumar, S AF Nounesis, G Ratna, BR Shin, S Flugel, RS Sprunt, SN Singh, A Litster, JD Shashidhar, R Kumar, S TI Melting of phospholipid tubules SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRYSTALLINE ORDER; LIPID TUBULES; MEMBRANES; SURFACTANT; BILAYERS; FIELD AB The melting of lipid-based microcylinders (tubules) has been investigated for systems with single and multiple bilayer walls using high field, magnetic birefringence, and precision microcalorimetry. The pretransitional behavior of both the magnetic birefringence and the specific heat is very different in tubules with a single bilayer wall from that of tubules with multiple bilayers. C1 USN, RES LAB, CTR BIOMOLEC SCI & ENGN, WASHINGTON, DC 20375 USA. KENT STATE UNIV, DEPT PHYS, KENT, OH 44242 USA. KENT STATE UNIV, INST LIQUID CRYSTAL, KENT, OH 44242 USA. MIT, DEPT PHYS, CAMBRIDGE, MA 02139 USA. RP Nounesis, G (reprint author), MIT, FRANCIS BITTER NATL MAGNET LAB, CAMBRIDGE, MA 02139 USA. NR 28 TC 12 Z9 12 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 6 PY 1996 VL 76 IS 19 BP 3650 EP 3653 DI 10.1103/PhysRevLett.76.3650 PG 4 WC Physics, Multidisciplinary SC Physics GA UW490 UT WOS:A1996UW49000046 ER PT J AU Lukin, K Li, JC Gilardi, R Eaton, PE AF Lukin, K Li, JC Gilardi, R Eaton, PE TI Anions stabilized by beta-nitro groups: The acidity and ortho-metalation of nitrocubanes - Penta- and hexanitrocubanes SO ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH LA English DT Article DE carbanions; cubanes; ortho-metalation; nitro compounds ID CHEMISTRY; CUBANES C1 UNIV CHICAGO,DEPT CHEM,CHICAGO,IL 60637. GEOCENTERS INC,LAKE HOPATCONG,NJ 07849. USN,RES LAB,STRUCT MATTER LAB,WASHINGTON,DC 20375. NR 24 TC 19 Z9 20 U1 0 U2 0 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0570-0833 J9 ANGEW CHEM INT EDIT JI Angew. Chem.-Int. Edit. Engl. PD MAY 3 PY 1996 VL 35 IS 8 BP 864 EP 866 DI 10.1002/anie.199608641 PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA UM246 UT WOS:A1996UM24600005 ER PT J AU Lukin, K Li, JC Gilardi, R Eaton, PE AF Lukin, K Li, JC Gilardi, R Eaton, PE TI Stable tin and lead derivatives of nitrocubanes: Their formation and use in multiple functionalization SO ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH LA English DT Article DE cubanes; lead compounds; ortho-metalation; nitro compounds; tin compounds ID NITROACETYLENES; SUBSTITUTION C1 UNIV CHICAGO,DEPT CHEM,CHICAGO,IL 60637. GEOCENTERS INC,LAKE HOPATCONG,NJ 07849. USN,RES LAB,STRUCT MATTER LAB,WASHINGTON,DC 20375. NR 19 TC 7 Z9 9 U1 0 U2 0 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 0570-0833 J9 ANGEW CHEM INT EDIT JI Angew. Chem.-Int. Edit. Engl. PD MAY 3 PY 1996 VL 35 IS 8 BP 866 EP 868 DI 10.1002/anie.199608661 PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA UM246 UT WOS:A1996UM24600006 ER PT J AU McClean, RE Campbell, ML Goodwin, RH AF McClean, RE Campbell, ML Goodwin, RH TI Depletion kinetics of Mo(a(7)S(3),a(5)S(2),a(5)D(J)) by N-2, SO2, CO2, N2O, and NO SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID TRANSITION-METAL ATOMS; GAS-PHASE; ELECTRON-AFFINITIES; OXIDATION REACTIONS; MO; SPECTROSCOPY; O-2; CR; NA AB The gas phase collisional disappearance of Mo(a(7)S(3),a(5)S(2),a(5)D(J)) in the presence of N-2, SO2, CO2, N2O, and NO over the temperature range 294-621 K and in the total pressure range 10-600 Torr is reported. Mo atoms were produced by the 248 nm photodissociation of Mo(CO)(6) and MoCl4 and detected by laser-induced fluorescence. The room temperature depletion rate constant of Mo(a(5)S(2)) + N-2 is (2.3 +/- 0.7) x 10(-11) cm(3) s(-1); the depletion rate constants of the a(5)D(J) are smaller and range from (16 +/- 8) x 10-(12) for Mo(a(5)D(0)) to (0.13 +/- 0.04) x 10(-12) cm(3) s(-1) for the other spin-orbit states. The depletion rate of all states of Mo by SO2 are on the order of the collision rate. Mo(a(7)S(3)) is found to be unreactive toward CO2, and the rate constant for the reaction of Mo(a(7)S(3)) with N2O is expressed as k(T) (2.0 +/- 0.5) x 10(-10) exp[-(9.8 +/- 0.3) kcal mol(-1)/RT] cm(3) s(-1). Termolecular kinetics are observed for Mo(a(7)S(3)) + NO with k(0) (2.6 +/- 0.3) x 10(-29) cm(6) s(-1), k(infinity) = (5.8 +/- 0.5) x 10(-11) cm(3) s(-1), and F-c = 0.72 +/- 0.07 at 296 K; the reaction rates for this reaction decrease with increasing temperature. Depletion rate constants of the reactions of the excited states of Mo with CO2, N2O, and NO are on the order of 10(-12)-10(-10) cm(3) s(-1); the depletion kinetics are complex and involve significant energy transfers. Results indicate that the electron configuration of Mo plays a role in its depletion kinetics. In all cases, Mo(4d(5)5s(1)a(5)S(2)) depletes faster than Mo(4d(4)5s(2)a(5)D(J)). The inefficient reactions of Mo(a(7)S(3)) with CO2 and N2O are attributed to the production of spin-forbidden states. RP McClean, RE (reprint author), USN ACAD,DEPT CHEM,ANNAPOLIS,MD 21402, USA. NR 36 TC 40 Z9 40 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAY 2 PY 1996 VL 100 IS 18 BP 7502 EP 7510 DI 10.1021/jp9532172 PG 9 WC Chemistry, Physical SC Chemistry GA UJ117 UT WOS:A1996UJ11700028 ER PT J AU Smith, G Volpano, D AF Smith, G Volpano, D TI Polymorphic typing of variables and references SO ACM TRANSACTIONS ON PROGRAMMING LANGUAGES AND SYSTEMS LA English DT Article DE languages; theory; verification; assignment; references; variables ID INFERENCE AB In this article we consider the polymorphic type checking of an imperative language. Our language contains variables, first-class references (pointers), and first-class functions. Variables, as in traditional imperative languages, are implicitly dereferenced, and their addresses (L-values) are not first-class values. Variables are easier to type check than references and, in many cases, lead to more general polymorphic types. We present a polymorphic type system for our language and prove that it is sound. Programs that use variables sometimes require weak types, as in Tofte's type system for Standard ML, but such weak types arise far less frequently with variables than with references. C1 USN,POSTGRAD SCH,DEPT COMP SCI,MONTEREY,CA 93943. RP Smith, G (reprint author), FLORIDA INT UNIV,SCH COMP SCI,MIAMI,FL 33199, USA. NR 19 TC 2 Z9 2 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 SN 0164-0925 J9 ACM T PROGR LANG SYS JI ACM Trans. Program. Lang. Syst. PD MAY PY 1996 VL 18 IS 3 BP 254 EP 267 DI 10.1145/229542.229544 PG 14 WC Computer Science, Software Engineering SC Computer Science GA UR828 UT WOS:A1996UR82800002 ER PT J AU Kolbe, R Kailasanath, K Young, T Boris, J Landsberg, A AF Kolbe, R Kailasanath, K Young, T Boris, J Landsberg, A TI Numerical simulations of flow modification of supersonic rectangular jets SO AIAA JOURNAL LA English DT Article AB Numerical simulations have been performed to study the flowfield and near-field noise of a supersonic rectangular jet with two paddles inserted into the how The paddles cause a strong flapping motion to develop that enhances mixing of the jet with the surroundings. These simulations have been used to determine the flapping motion's frequency, the mixing enhancement, the near-field noise, and the thrust loss associated with the paddles and to study the acoustic feedback mechanism that modulates the flapping motion. The flapping frequency has been estimated using the pitot pressure distributions at a sequence of times and Fourier analysis of the local pressure and z component of velocity. For paddles located x/h = 7.3 from the nozzle, where h is the narrow dimension of the nozzle, a frequency of 4700 Hz [St(h) = 0.136] with an amplitude of 157.5 dB at the nozzle lip has been predicted and is in agreement with experimental results. The pitot pressure drop, the mass, and the x-momentum fluxes along the flow direction have been used as a measure of jet mixing for jets with and without paddles inserted into the flow. In our numerical simulations, a control volume approach was used to estimate the thrust loss caused by the insertion of the paddles. The computational value of 13% is close to the experimental value of 14.4%, considering that the physical support for the paddles in the experiments is not included in the simulations. A special sequence of local pressure distribution plots, which highlight the acoustic waves, has been used to study the feedback mechanism that modulates the flapping motion. C1 USN, RES LAB, CTR REACT FLOW & DYNAM SYST, WASHINGTON, DC 20375 USA. RP USN, RES LAB, LAB COMPUTAT PHYS & FLUID DYNAM, CODE 6410, WASHINGTON, DC 20375 USA. NR 19 TC 9 Z9 9 U1 0 U2 1 PU AMER INST AERONAUTICS ASTRONAUTICS PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 EI 1533-385X J9 AIAA J JI AIAA J. PD MAY PY 1996 VL 34 IS 5 BP 902 EP 908 DI 10.2514/3.13166 PG 7 WC Engineering, Aerospace SC Engineering GA UH935 UT WOS:A1996UH93500004 ER PT J AU Jones, KD Platzer, ME AF Jones, KD Platzer, ME TI Time-domain analysis of low-speed airfoil flutter SO AIAA JOURNAL LA English DT Article AB A time-domain aeroelastic analysis code is described for single airfoils and two-foil systems in incompressible, inviscid flow Flow solutions are obtained using a time-stepping panel code, and airfoil motions are computed using a two-degree-of-freedom spring/mass model, The time-stepping aeroelastic code is evaluated through comparisons with several classical frequency-domain studies for single-degree-of-freedom pitching motion. Results show excellent agreement with past studies and provide a look into the evolution of the motion in time, Additionally, using a two-foil system, it is shown that flutter of a trailing airfoil can be controlled by proper oscillation and phasing of a leading airfoil, Three applications of the aeroelastic code are presented, including a feedback loop to actively stabilize flutter of a trailing airfoil, simulations of wake interference in rotary-wing flowfields, and simulations of flutter in ground effect. RP Jones, KD (reprint author), USN,POSTGRAD SCH,DEPT AERONAUT & ASTRONAUT,MAIL CODE AA-JO,MONTEREY,CA 93943, USA. NR 15 TC 7 Z9 7 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD MAY PY 1996 VL 34 IS 5 BP 1027 EP 1033 DI 10.2514/3.13183 PG 7 WC Engineering, Aerospace SC Engineering GA UH935 UT WOS:A1996UH93500021 ER PT J AU Requena, R Lassen, LF Karakla, DW Parker, G AF Requena, R Lassen, LF Karakla, DW Parker, G TI Spontaneous cerebrospinal otorrhea after ear canal irrigation: Incidental diagnosis of Mondini's dysplasia SO AMERICAN JOURNAL OF OTOLARYNGOLOGY LA English DT Article ID RECURRENT MENINGITIS; FLUID OTORRHEA C1 USN,MED CTR,DEPT OTOLARYNGOL HEAD & NECK SURG,PORTSMOUTH,VA 23708. NR 21 TC 2 Z9 2 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 SN 0196-0709 J9 AM J OTOLARYNG JI Am. J. Otolaryngol. PD MAY-JUN PY 1996 VL 17 IS 3 BP 202 EP 206 DI 10.1016/S0196-0709(96)90061-7 PG 5 WC Otorhinolaryngology SC Otorhinolaryngology GA UK944 UT WOS:A1996UK94400009 PM 8827281 ER PT J AU Limjoco, UR Nelson, LD AF Limjoco, UR Nelson, LD TI CT as the initial diagnostic tool for small-bowel obstruction SO AMERICAN JOURNAL OF ROENTGENOLOGY LA English DT Letter RP Limjoco, UR (reprint author), USN HOSP,TWENTYNINE PALMS,CA 92278, USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER ROENTGEN RAY SOC PI RESTON PA 1891 PRESTON WHITE DR SUBSCRIPTION FULFILLMENT, RESTON, VA 22091 SN 0361-803X J9 AM J ROENTGENOL JI Am. J. Roentgenol. PD MAY PY 1996 VL 166 IS 5 BP 1227 EP 1227 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA UF853 UT WOS:A1996UF85300043 PM 8615276 ER PT J AU Khalfayan, EE Sharkey, PF Alexander, AH Bruckner, JD Bynum, EB AF Khalfayan, EE Sharkey, PF Alexander, AH Bruckner, JD Bynum, EB TI The relationship between tunnel placement and clinical results after anterior cruciate ligament reconstruction SO AMERICAN JOURNAL OF SPORTS MEDICINE LA English DT Article AB To correlate clinical results after anterior cruciate ligament reconstruction with tunnel placement measured radiographically, we prospectively studied 128 patients who had arthroscopically assisted bone-patellar tendon-bone reconstructions. Patients with bilateral anterior cruciate ligament reconstructions, other significant knee ligament injuries, or those undergoing chondroplasty or meniscal repairs were excluded, leaving 42 patients. The relationship between radiographic tunnel position and clinical results was determined using the Lysholm score, KT-1000 arthrometer testing, the Tegner activity level, and the pivot shift and Lachman tests. Clinical results correlated positively with posterior femoral tunnel placement on lateral radiographs and negatively with excessive anterior tibial tunnel placement. Specifically, when femoral tunnels were placed at least 60% posterior along Blumensaat's line and tibial tunnels were at least 20% posterior along the tibial plateau, 69% of patients had good or excellent Lysholm scores and 79% had KT-1000 arthrometer maximum manual side-to-side differences of 3 mm or less. When the above criteria were not met, 50% of patients had good or excellent Lysholm scores and 22% had KT-1000 arthrometer maximum manual side-to-side differences of 3 mm or less. This close correlation indicates that satisfactory radiographic tunnel position influences outcome after anterior cruciate ligament reconstruction. C1 USN,DEPT ORTHOPAED SURG,MED CTR,OAKLAND,CA 94627. NR 40 TC 116 Z9 126 U1 0 U2 0 PU AMER ORTHOPAEDIC SOC SPORT MED PI WALTHAM PA 230 CALVARY STREET, WALTHAM, MA 02154 SN 0363-5465 J9 AM J SPORT MED JI Am. J. Sports Med. PD MAY-JUN PY 1996 VL 24 IS 3 BP 335 EP 341 DI 10.1177/036354659602400315 PG 7 WC Orthopedics; Sport Sciences SC Orthopedics; Sport Sciences GA UL557 UT WOS:A1996UL55700015 PM 8734885 ER PT J AU Cross, ER Newcomb, WW Tucker, CJ AF Cross, ER Newcomb, WW Tucker, CJ TI Use of weather data and remote sensing to predict the geographic and seasonal distribution of Phlebotomus papatasi in southwest Asia SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Article ID LEISHMANIA INFECTING MAN; CUTANEOUS LEISHMANIASIS; SAUDI-ARABIA; WILD ANIMALS; PARASITES; VECTORS AB Sandfly fever and leishmaniasis were major causes of infectious disease morbidity among military personnel deployed to the Middle East during World War II. Recently, leishmaniasis has been reported in the United Nations Multinational Forces and Observers in the Sinai. Despite these indications of endemicity, no cases of sandfly fever and only 31 cases of leishmaniasis have been identified among U.S. veterans of the Persian Gulf War. The distribution in the Persian Gulf of the vector, Phlebotomus papatasi, is thought to be highly dependent on environmental conditions, especially temperature and relative humidity. A computer model was developed using the occurrence of P. papatasi as the dependent variable and weather data as the independent variables. The results of this model indicated that the greatest sand fly activity and thus the highest risk of sandfly fever and leishmania infections occurred during the spring/summer months before U.S. troops were deployed to the Persian Gulf. Because the weather model produced probability of occurrence information for locations of the weather stations only, normalized difference vegetation index (NDVI) levels from remotely sensed Advanced Very High Resolution Radiometer satellites were determined for each weather station. From the results of the frequency of NDVI levels by probability of occurrence, the range of NDVI levels for presence of the vector was determined. The computer then identified all pixels within the NDVI range indicated and produced a computer-generated map of the probable distribution of P. papatasi. The resulting map expanded the analysis to areas where there were no weather stations and from which no information was reported in the literature, identifying these areas as having either a high or low probability of vector occurrence. C1 NASA,GODDARD SPACE FLIGHT CTR,TERR PHYS LAB,GREENBELT,MD 20771. USN,MED RES INST,INFECT DIS THREAT ASSESSMENT,BETHESDA,MD. NR 24 TC 86 Z9 88 U1 0 U2 8 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DRIVE SUITE 130, MCLEAN, VA 22101 SN 0002-9637 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD MAY PY 1996 VL 54 IS 5 BP 530 EP 536 PG 7 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA UP632 UT WOS:A1996UP63200017 PM 8644911 ER PT J AU Khuri, SF Valeri, CR Loscalzo, J Michelson, AD AF Khuri, SF Valeri, CR Loscalzo, J Michelson, AD TI Heparin effect on platelets and fibrinolysis - Reply SO ANNALS OF THORACIC SURGERY LA English DT Letter C1 HARVARD UNIV,SCH MED,BOSTON,MA 02132. WHITAKER CARDIOVASC INST,DEPT MED,USN,BLOOD RES LAB,BOSTON,MA. BOSTON UNIV,SCH MED,EVANS DEPT MED,BOSTON,MA 02118. UNIV MASSACHUSETTS,SCH MED,CTR PLATELET FUNCT STUDIES,DEPT PEDIAT,WORCESTER,MA. UNIV MASSACHUSETTS,SCH MED,CTR PLATELET FUNCT STUDIES,DEPT SURG,WORCESTER,MA. RP Khuri, SF (reprint author), BRIGHAM & WOMENS HOSP,BROCKTON W ROXBURY VET AFFAIRS MED CTR,DEPT SURG,BOSTON,MA 02132, USA. NR 4 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0003-4975 J9 ANN THORAC SURG JI Ann. Thorac. Surg. PD MAY PY 1996 VL 61 IS 5 BP 1590 EP 1591 PG 2 WC Cardiac & Cardiovascular Systems; Respiratory System; Surgery SC Cardiovascular System & Cardiology; Respiratory System; Surgery GA UG909 UT WOS:A1996UG90900093 ER PT J AU Bergan, JJ Murray, J Greason, K AF Bergan, JJ Murray, J Greason, K TI Subfascial endoscopic perforator vein surgery: A preliminary report SO ANNALS OF VASCULAR SURGERY LA English DT Article ID VENOUS STASIS ULCERATION; SURGICAL TREATMENT; LIGATION; INSUFFICIENCY; HYPOTHESIS; MANAGEMENT; DISEASE; ULCERS; REFLUX AB Although the open Linton subfascial perforator vein interruption operation succeeded, for the most part, in preventing recurrent venous ulceration, it was associated with morbidity and prolonged hospitalization. We have attempted to obtain the beneficial effects of perforator interruption by the less invasive procedure of subfascial endoscopic perforator vein surgery using laparoscopic instrumentation and limited or no hospitalization. A total of 31 consecutive operations were performed in 30 patients. Sixteen women and 14 men were entered into the study, and all of them had severe chronic venous insufficiency with either open or healed ulcers. Operations were carried out without gas insufflation, in 17 without a hemostatic tourniquet, and in 13 entirely on an outpatient basis. The 18 hospitalizations produced a total of 49 days of inpatient care (mean 2.72 days). One to six perforating veins were encountered in these operations, and veins identified as perforators were electrocoagulated or clipped and sectioned. Sixteen limbs had severe chronic venous insufficiency or healed ulcers, and 15 had open ulcers. In 13 limbs, ulcers were intermittently present for 1 to 5 years. Seven of these healed within 4 weeks of operation and four others within 8 weeks. Two healed more than 8 weeks after surgery. In two limbs with ulcers that were present for 1 to 6 months, healing took place within 4 weeks of the operation in both. Complications included atelectasis in one patient, cellulitis requiring antibiotic therapy in three, wound hematomas not requiring intervention in two, and wound seroma not requiring therapy in one. This preliminary experience suggests that perforator vein interruption can be accomplished using existing instrumentation and a variety of technical modifications to achieve the objectives of the Linton operation without the attendant morbidity. Videoscopic instrumentation obtains benefits of subfascial perforator vein interruption without morbidity of the open operations. This preliminary study suggests that the operative procedure is attended by minimum morbidity without the need for rehospitalization. Long-term observation will be required to assess the procedure definitively, but the short-term objectives can be safely accomplished with minimum use of inpatient facilities. C1 SCRIPPS CLIN & HOSP,LA JOLLA,CA. USN,MED CTR,SAN DIEGO,CA 92152. NR 46 TC 56 Z9 62 U1 0 U2 0 PU QUALITY MEDICAL PUBLISHING INC PI ST LOUIS PA 11970 BORMAN DR, STE 222, ST LOUIS, MO 63146 SN 0890-5096 J9 ANN VASC SURG JI Ann. Vasc. Surg. PD MAY PY 1996 VL 10 IS 3 BP 211 EP 219 DI 10.1007/BF02001884 PG 9 WC Surgery; Peripheral Vascular Disease SC Surgery; Cardiovascular System & Cardiology GA UQ357 UT WOS:A1996UQ35700002 PM 8792987 ER PT J AU Hill, RT Straube, WL Palmisano, AC Gibson, SL Colwell, RR AF Hill, RT Straube, WL Palmisano, AC Gibson, SL Colwell, RR TI Distribution of sewage indicated by Clostridium perfringens at a deep-water disposal site after cessation of sewage disposal SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID MID-ATLANTIC BIGHT; SEEP-I; CONSTITUENTS; PARTICLES; SEDIMENTS; SLOPE AB Clostridium perfringens, a marker of domestic sewage contamination, was enumerated in sediment samples obtained from the vicinity of the 106-Mile Site 1 month and 1 year after cessation of sewage disposal at this site. C. perfringens counts in sediments collected at the disposal site and from stations 26 nautical miles (ca. 48 km) and 50 nautical miles (ca. 92 km) to the southwest of the site were, in general, more than 10-fold higher than counts from an uncontaminated reference site, C. perfringens counts at the disposal site were not significantly different between 1992 and 1993, suggesting that sewage sludge had remained in the benthic environment at this site. At stations where C. perfringens counts were elevated (i.e., stations other than the reference station), counts were generally higher in the top 1 cm and decreased down to 5 cm. In some cases, C. perfringens counts in the bottom 4 or 5 cm showed a trend of higher counts in 1993 than in 1992, suggesting bioturbation. We conclude that widespread sludge contamination of the benthic environment has persisted for at least 1 year after cessation of ocean sewage disposal at the 106-Mile Site. C1 UNIV MARYLAND,INST BIOTECHNOL,CTR MARINE BIOTECHNOL,COLLEGE PK,MD 20740. OFF NAVAL RES,ARLINGTON,VA 22217. NR 23 TC 26 Z9 27 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD MAY PY 1996 VL 62 IS 5 BP 1741 EP 1746 PG 6 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA UJ228 UT WOS:A1996UJ22800040 PM 8633872 ER PT J AU Sun, WQ Meng, M Kumar, G Geelhaar, LA Payne, GF Speedie, MK Stacy, JR AF Sun, WQ Meng, M Kumar, G Geelhaar, LA Payne, GF Speedie, MK Stacy, JR TI Biological denitration of propylene glycol dinitrate by Bacillus sp ATCC 51912 SO APPLIED MICROBIOLOGY AND BIOTECHNOLOGY LA English DT Article ID GLYCERYL TRINITRATE; DEGRADATION AB In previous studies, bacterial cultures were isolated that had the ability to degrade the nitrate ester glyceryl trinitrate (i.e. nitroglycerin). The goal of the present study was to examine the ability of resting cells and cell-free extracts of the isolate Bacillus sp. ATCC 51912 to degrade the more recalcitrant nitrate ester propylene glycol dinitrate (PGDN). It was observed that the PGDN-denitrating activity was expressed during growth even when cells were cultured in the absence of nitrate esters. This indicates that nitrate esters are not required for expression of denitration activity. Using cell-free extracts, PCDN was observed to be sequentially denitrated to propylene glycol mononitrate (PGMN) and propylene glycol with the second denitration step proceeding more slowly than the first. Also it was observed that dialysis of the cell-free extracts did not affect denitration activity indicating that regenerable cofactors [e.g. NAD(P)H or ATP] are not required for denitration. C1 UNIV MARYLAND BALTIMORE CTY,DEPT CHEM & BIOCHEM ENGN,BALTIMORE,MD 21228. UNIV MARYLAND BALTIMORE CTY,AGR BIOTECHNOL CTR,BALTIMORE,MD 21228. UNIV MARYLAND,DEPT PHARMACEUT SCI,BALTIMORE,MD 21201. USN,CTR SURFACE WARFARE,INDIAN HEAD,MD 20640. NR 13 TC 3 Z9 3 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0175-7598 J9 APPL MICROBIOL BIOT JI Appl. Microbiol. Biotechnol. PD MAY PY 1996 VL 45 IS 4 BP 525 EP 529 PG 5 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA UP628 UT WOS:A1996UP62800013 PM 8785037 ER PT J AU Ewing, KJ Dagenais, DM Bucholtz, F Aggarwal, ID AF Ewing, KJ Dagenais, DM Bucholtz, F Aggarwal, ID TI Fiber-optic Raman detection of trace levels of phosphonate vapors chemisorbed onto an alumina substrate SO APPLIED SPECTROSCOPY LA English DT Article DE fiber-optic Raman; trace gas analysis; phosphonates; preconcentration ID SURFACE; SENSOR AB Detection of ppm(v) levels of the nerve agent simulants dimethyl methylphosphonate (DMMP) and diisopropyl methylphosphonate (DIMP) by chemisorption to an alumina surface followed by fiber-optic Raman spectroscopic determination is described. Real-time measurements of the increase in the Raman line intensities with respect to time for DMMP and DIMP chemisorption to alumina are presented. A detection limit at the 95% confidence interval of 6 ppm(v) is calculated for DMMP vapours at a vapor flow rate of 100 mL/min. Factors which limit lower detection limits are identified and possible solutions presented. RP Ewing, KJ (reprint author), USN,RES LAB,DIV OPT SCI,CODE 5603,WASHINGTON,DC 20375, USA. NR 16 TC 6 Z9 6 U1 0 U2 2 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD MAY PY 1996 VL 50 IS 5 BP 614 EP 618 DI 10.1366/0003702963905871 PG 5 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA UM065 UT WOS:A1996UM06500014 ER PT J AU Evans, NR Teays, TJ Taylor, LL Lester, JB Hindsley, RB AF Evans, NR Teays, TJ Taylor, LL Lester, JB Hindsley, RB TI The temperature of the supergiant alpha Per SO ASTRONOMICAL JOURNAL LA English DT Article ID ENERGY-DISTRIBUTIONS; PHOTOMETRIC SYSTEMS; ANGULAR DIAMETERS; MODEL ATMOSPHERES; F-SUPERGIANTS; OPEN CLUSTERS; STARS; CALIBRATION; SCALE; COLORS AB Because the bright supergiant alpha Per is located in cluster, and because its angular diameter has been measured, its log g is known observationally, as is its atmospheric microturbulence. Using these observed parameters, we compare its energy distribution derived from IUE spectra and B, V, R, I, J, and K with model atmospheres convolved with instrumental sensitivity functions. The two most important advances in this study as compared with previous work are the use of well-calibrated ultraviolet fluxes and the use of models with an appropriate microturbulence. Because the ultraviolet flux is sensitive to log g and microturbulence, as well as temperature, we fix log g at 1.5 and microturbulence at 4 km s(-1), and derive the temperature from the best fit to the energy distribution (6270 K). Other recent temperature determinations are discussed, as are the sources of error. (C) 1996 American Astronomical Society. C1 YORK UNIV,DEPT PHYS & ASTRON,N YORK,ON M3J 1P3,CANADA. COMP SCI CORP,CTR SCI RES,SCI PROGRAMS,LANHAM,MD 20706. UNIV TORONTO,ERINDALE COLL,DEPT ASTRON,MISSISSAUGA,ON L5L 1C6,CANADA. USN OBSERV,ASTROMETRY DEPT,WASHINGTON,DC 20392. RP Evans, NR (reprint author), HARVARD SMITHSONIAN CTR ASTROPHYS,60 GARDEN ST,MAIL STOP 4,CAMBRIDGE,MA 02138, USA. NR 50 TC 8 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD MAY PY 1996 VL 111 IS 5 BP 2099 EP 2105 DI 10.1086/117946 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UG899 UT WOS:A1996UG89900031 ER PT J AU Knapp, GR Gunn, JE Bowers, PF Poritz, JFV AF Knapp, GR Gunn, JE Bowers, PF Poritz, JFV TI Limits on ionized gas in globular clusters SO ASTROPHYSICAL JOURNAL LA English DT Article DE globular clusters, general; ISM, abundances ID X-RAY SOURCES; NEUTRAL HYDROGEN; SCALE HEIGHT; MASS-LOSS; ORBITAL PERIOD; RED GIANTS; NGC 6624; SEARCH; DUST; PULSARS AB Globular clusters are expected to accumulate interstellar gas due to mass loss from their stars. A sensitive search of six clusters for free-free emission from ionized gas at 8.4 GHz using the Very Large Array failed to detect any gas, with limits well below the expected accumulation from mass loss if the gas remains in the cluster. However, simple models of the equilibrium distribution of photoionized gas show that the velocity dispersion of the gas is greater than that of the stars, and beyond a critical radius the gas flows out of the cluster as a wind. The expected amounts of accumulated gas are then below the detection threshold of the observations. Fifteen radio point sources were detected in the six globular cluster fields. The majority are likely to be background sources, but five are associated with objects which are known cluster members: four probable low-mass X-ray binaries in Pal 2, NGC 6440, NGC 6624 and NGC 7078, and the planetary nebula K648 in NGC 7078. Two other radio sources in the field of NGC 7078 may also belong to this cluster. C1 USN OBSERV,ASTROMETRY DEPT,USNO NRL OPT INTERFEROMETER PROJECT,WASHINGTON,DC 20392. CORNELL UNIV,DEPT PHYS,ITHACA,NY 14853. RP Knapp, GR (reprint author), PRINCETON UNIV,DEPT ASTROPHYS SCI,PRINCETON,NJ 08544, USA. NR 88 TC 27 Z9 29 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAY 1 PY 1996 VL 462 IS 1 BP 231 EP 240 DI 10.1086/177144 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UG298 UT WOS:A1996UG29800023 ER PT J AU Schmidt, EG Carruthers, GR AF Schmidt, EG Carruthers, GR TI Far-ultraviolet stellar photometry: Fields centered on rho Ophiuchi and the Galactic center SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE Galaxy, center; ISM, individual (rho Ophiuchi); stars, fundamental parameters; surveys; ultraviolet, stars AB Far-ultraviolet photometry is presented for 121 objects in a 20 degrees diameter field centered on rho Oph and for 649 objects in a field covering the Galactic center. Broadband magnitudes with effective wavelengths of 1375 Angstrom and 1781 Angstrom are given. The Galactic center field overlaps two fields which were discussed in an earlier paper. Eighty-eight percent of the ultraviolet objects in the rho Oph field were identified with visible stars using the SIMBAD database, while only 9% of the objects are blends of early-type stars too close together to separate with our resolution. The photometric calibration was studied in detail, and corrections for nonlinearity were derived for the fields analyzed earlier as well as those discussed here. For stars in common between the Galactic center field and the previous fields, a comparison of the magnitudes yielded estimates of the internal errors of the magnitudes of sigma(1375) = 0.13 mag and sigma(1781) = 0.21 mag. A collated list of stars in the fields covering the Galactic center and incorporating the revised calibration is presented and compared with the S201 data of the same region. The properties of the sample of ultraviolet objects in the rho Oph field are briefly commented upon. C1 USN,RES LAB,EO HULBURT CTR SPACE RES,WASHINGTON,DC 20375. RP Schmidt, EG (reprint author), UNIV NEBRASKA,DEPT PHYS & ASTRON,LINCOLN,NE 68588, USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD MAY PY 1996 VL 104 IS 1 BP 101 EP & DI 10.1086/192294 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UG195 UT WOS:A1996UG19500005 ER PT J AU Leggett, SK Allard, F Berriman, G Dahn, CC Hauschildt, PH AF Leggett, SK Allard, F Berriman, G Dahn, CC Hauschildt, PH TI Infrared spectra of low-mass stars: Toward a temperature scale for red dwarfs SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE infrared, stars; stars, atmospheres; stars, fundamental parameters; stars, low mass, brown dwarfs ID NEARBY M-DWARFS; STANDARD STARS; BROWN DWARFS; LUMINOSITY FUNCTION; ABSOLUTE FLUX; PHOTOMETRY; SEQUENCE; SYSTEM; CALIBRATION; MAGNITUDES AB We present new low-resolution (R similar to 250) 1.0-2.4 mu m spectra for 13 red dwarf stars. The sample size is increased to 16 by including other published infrared spectra. New, as well as published, red spectra are presented for 10 of these 16 stars, and new and published VRIJHKLL' photometry is also presented. Both halo and disk stars are included in the sample, which covers a range of spectral type from dM0 to dM6.5. We derive bolometric luminosities and bolometric corrections from the observational data, finding good agreement with earlier results for the disk stars. We fit synthetic spectra generated by Allard & Hauschildt's state-of-the-art model atmospheres to the observed spectra. Although some discrepancies remain between the theoretical and observed spectra, we find that the molecular features give a consistent value for effective temperature across the entire observed wavelength range. The T-eff values and radii derived, and their dependency on metallicity, are in agreement with the most recent structural models of low-mass stars, removing the long-standing discrepancy between the observed and calculated locations of such stars in the H-R diagram, at least for stars more massive than 0.1 M.. C1 JOINT ASTRON CTR,HILO,HI 96720. UNIV BRITISH COLUMBIA,DEPT GEOPHYS & ASTRON,VANCOUVER,BC V6T 1Z4,CANADA. GEN SCI CORP,LAUREL,MD 20707. USN OBSERV,FLAGSTAFF,AZ 86002. ARIZONA STATE UNIV,DEPT PHYS & ASTRON,TEMPE,AZ 85287. UNIV HAWAII,HILO,HI 96720. OI Leggett, Sandy/0000-0002-3681-2989 NR 73 TC 223 Z9 223 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD MAY PY 1996 VL 104 IS 1 BP 117 EP 143 DI 10.1086/192295 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UG195 UT WOS:A1996UG19500006 ER PT J AU Saxena, VK Durkee, PA Menon, S Anderson, J Burns, KL Nielsen, KE AF Saxena, VK Durkee, PA Menon, S Anderson, J Burns, KL Nielsen, KE TI Physico-chemical measurements to investigate regional cloud climate feedback mechanisms SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT Joint 8th CACGP/2nd IGAC Conference on Global Atmospheric Chemistry CY SEP 05-09, 1994 CL FUJI, JAPAN SP Int Global Atmospher Chem Project, Commiss Atmospher Chem & Global Pollut DE cloud albedo; cloud water acidity; anthropogenic sulfates; AVHRR; regional climate ID SOLAR-RADIATION; CHEMISTRY; ACIDITY; CAPTEX; ALBEDO AB On a regional scale, cloud-climate feedback mechanisms are investigated by analyzing the impact of anthropogenic sulfur emissions on the microstructure and short-wave albedo of clouds formed at a mountain-top location and simultaneously observing these clouds by AVHRR (Advance Very High Resolution Radiometer) aboard the NOAA (National Oceanographic and Atmospheric Administration) satellites. Cloud droplet number concentrations (CDNC) and ionic composition of cloud water are measured in situ along with meteorological parameters. The thickness of the overlying clouds and the 48 h back-trajectories of air masses are determined from on site measurements and Hybrid Single Particle Lagrangian Integrated Trajectory (HY-SPLIT) model. In general, more acidic clouds were found to have smaller effective radii of droplets but larger CDNC. The short-wave albedo of clouds determined from in situ measurements decreased with an increase in the cloud water pH which was largely affected by the sulfate concentration in the cloud forming air mass. For six coincidental cloud events, the AVHRR retrieved cloud albedo (channel 1, wavelength = 0.63 mu m) agreed well with those determined from in situ microphysical measurements, the correlation coefficient being 0.95. These findings indicate that the sulfate contents of air masses are capable of influencing cloud-climate feedback mechanisms by changing the albedo of thin, continental clouds. C1 USN,POSTGRAD SCH,DEPT METEOROL,MONTEREY,CA 93943. RP Saxena, VK (reprint author), N CAROLINA STATE UNIV,DEPT MARINE EARTH & ATMOSPHER SCI,BOX 8208,RALEIGH,NC 27695, USA. NR 29 TC 14 Z9 14 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAY PY 1996 VL 30 IS 10-11 BP 1573 EP 1579 DI 10.1016/1352-2310(95)00453-X PG 7 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA UH179 UT WOS:A1996UH17900006 ER PT J AU Shender, BS AF Shender, BS TI High performance supine flight assessment using the NAWC dynamic flight simulator SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article AB Introduction: To determine the feasibility of high-performance supine flight, the USAF Canopy Escape Module (65 degrees seat-back-angle) was modified and deployed into the Naval Air Warfare Center Dynamic Flight Simulator. Methods: Seven male subjects performed a flight syllabus consisting of instrument flight maneuvers (high-C level turns, ILS task, vertical S-2, Half Cuban Eight). Subjects were trained and performed under both Ig(static) and dynamic conditions in supine and upright postures. Data were assessed to determine the effects of motion (G) and seat position. A weighted objective performance grading scheme was devised based on the ability to achieve specified flight parameters. Results: This paper presents the analysis of the first two tasks. During the turns, motion effects did not effect the ability to maintain specified G loads when supine, whereas there were significant differences when upright. Also, there were lower error rates under static, as compared to dynamic, conditions. Even though subjects demonstrated lower error rates during dynamic turns when upright, there were few significant differences referable to body position. Overall, subjects with the most flight experience performed better upright than supinated, while a naive subject flew significantly better supine. Notably, one subject did experience a C-induced loss of consciousness (G-LOC) and an almost LOC event during a supinated high-G turn. Body position or motion effects did not significantly alter ILS task performance. Conclusions: High performance supine flight is feasible and additional study is warranted. important and unanticipated performance-related decrements were discovered only through the use of dynamic flight simulation. RP Shender, BS (reprint author), USN,AIR WARFARE CTR,AIR DIV WARMINSTER,POB 5152,CODE 464100R15,ALEXANDRIA,VA, USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD MAY PY 1996 VL 67 IS 5 BP 414 EP 422 PG 9 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA UH185 UT WOS:A1996UH18500002 PM 8725466 ER PT J AU Barker, CO Bellenkes, AH AF Barker, CO Bellenkes, AH TI US naval helicopter mishaps: Cockpit egress problems SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article ID CRASHES AB Introduction: A number of potential problems are associated with egress from the helicopter cockpit in the post-crash phase of a mishap. The purpose of this study was to identify the egress problems experienced by pilots in U.S. Navy/Marine Corp helicopter cockpits, and to propose a priority of preventive interventions. Method: Using Naval Safety Center data, we reviewed 1980-94 Class A helicopter mishap narratives. We identified and categorized cockpit egress problems reported by pilots. The data are described in terms of problem category, helicopter type, crash terrain, and time of day. Results: Of the 210 survivable mishaps, 489 egress problems were reported in 128 mishaps, 61% involved aircrew factors, 16% environmental factors, 12% were related to helicopter factors, and 11% to cockpit factors. Of the 128 mishaps, 67.5% occurred during daytime, 32.5% at night, 64% in overwater crashes, 26% over land, and 10% over flight decks. The most significant, but uncommon, injuries involved the ''stroking seat.'' Conclusions: Egress hazards can be minimized by the implementation of more intensive underwater egress training, crashworthy fuel systems, better design of cockpit exits and hatches, better restraint systems, better crashworthy seats, underwater visual aids, and more streamlined personal equipment. Engineering validation is needed before committing to suggested interventions. RP Barker, CO (reprint author), USN,AEROSP & OPERAT MED INST,NAS,CODE 32R,220 HOVEY RD,PENSACOLA,FL 32508, USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD MAY PY 1996 VL 67 IS 5 BP 480 EP 485 PG 6 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA UH185 UT WOS:A1996UH18500014 PM 8725478 ER PT J AU Lippmann, TC Brookins, AH Thornton, EB AF Lippmann, TC Brookins, AH Thornton, EB TI Wave energy transformation on natural profiles SO COASTAL ENGINEERING LA English DT Article ID RANDOM BREAKING WAVES; SURF ZONE; LONGSHORE-CURRENT; BEACH; MODEL; SATURATION AB A wave energy transformation model, which includes wave breaking within the surf zone described by surface rollers, is developed for randomly varying waves over arbitrary bathymetry, The model includes roller energy gradients in the energy flux balance, and further specifies the dissipation function based on roller theory following Svendsen. Root-mean-square wave heights, H-rms, are found across the surf zone by numerical iteration, and compare well with field data acquired on both barred and near-planar beaches. The model has two free parameters, sigma, the mean angle to vertical of the wave/roller interface roughly representing the type of breaker, and gamma, a measure of breaking wave saturation equal to the ratio of H-rms to local depth. Optimal values of both parameters are chosen by model fitting, and show the model to be insensitive to sigma. Although the model is sensitive to the choice of gamma, values are consistent with field data. The surface roller model behaves similarly to the bore dissipation model of Thornton and Guza for a particular parameter choice, and is used to decrease model dependence to one input parameter, gamma. RP Lippmann, TC (reprint author), USN,POSTGRAD SCH,DEPT OCEANOG,MONTEREY,CA 93943, USA. NR 37 TC 41 Z9 43 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3839 J9 COAST ENG JI Coast. Eng. PD MAY PY 1996 VL 27 IS 1-2 BP 1 EP 20 DI 10.1016/0378-3839(95)00036-4 PG 20 WC Engineering, Civil; Engineering, Ocean SC Engineering GA UT261 UT WOS:A1996UT26100001 ER PT J AU Werking, RH AF Werking, RH TI Changes and continuities SO COLLEGE & RESEARCH LIBRARIES LA English DT Editorial Material RP Werking, RH (reprint author), USN ACAD,ANNAPOLIS,MD 21402, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU ASSN COLL RES LIBR PI CHICAGO PA 50 E HURON ST, CHICAGO, IL 60611 SN 0010-0870 J9 COLL RES LIBR JI Coll. Res. Libr. PD MAY PY 1996 VL 57 IS 3 BP 231 EP 233 PG 3 WC Information Science & Library Science SC Information Science & Library Science GA UM812 UT WOS:A1996UM81200005 ER PT J AU Lewis, T Rosemberg, D AF Lewis, T Rosemberg, D TI Is it too late for Apple Computer? SO COMPUTER LA English DT Editorial Material RP Lewis, T (reprint author), USN,POSTGRAD SCH,CODE CS,MONTEREY,CA 93943, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0018-9162 J9 COMPUTER JI Computer PD MAY PY 1996 VL 29 IS 5 BP 8 EP & DI 10.1109/MC.1996.493395 PG 4 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA UJ860 UT WOS:A1996UJ86000002 ER PT J AU Lewis, T AF Lewis, T TI The next 10,000(2) years .1. SO COMPUTER LA English DT Article AB As microprocessor advances begin to level off, communication network deployment will keep accelerating, and software engineering must face the prospect of radical change if it is to keep pace, The intersection of these ascending and descending technologies will propel. the high-tech world into a new model of computing by the year 2012. Software is the steam that drives the engines of the Information Age, but clearly it is not keeping up with developments on the hardware side. Historical trends suggest that further progress in programmer productivity and programming-language power over the next 10,000(2) years is highly unlikely. With a large percentage of programmers maintaining legacy code, the resources available for innovation are limited. In fact, software innovation will have to come from a 5 percent fringe of artisans and nontraditional thinkers outside the current programming language and software engineering establishment. RP Lewis, T (reprint author), USN,POSTGRAD SCH,MONTEREY,CA 93940, USA. NR 18 TC 6 Z9 8 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0018-9162 J9 COMPUTER JI Computer PD MAY PY 1996 VL 29 IS 5 BP 78 EP & DI 10.1109/2.494085 PG 10 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA UJ860 UT WOS:A1996UJ86000011 ER PT J AU Browning, VM Soulen, RJ Candela, GA Eraker, JH AF Browning, VM Soulen, RJ Candela, GA Eraker, JH TI Magnetic susceptibility of materials screened for use in fabricating a nonmagnetic liquid helium dewar SO CRYOGENICS LA English DT Article DE magnetic susceptibility; materials; SQUID AB In order to obtain a low noise environment for optimum performance of SQUID sensors, it is essential to minimize the magnetic signal of the materials used in the SQUID cold electronics and the structures surrounding these sensors. We have, therefore, screened samples for potential use in the fabrication of a low-noise dewar that would house a low-T-c SQUID device. Susceptibility measurements were made at room temperature and 4.5 K in order to determine if the materials would be good candidates for use in the construction of the dewar. The results of these magnetic susceptibility measurements are reported together with the materials' use and supplier. C1 SFA INC,LANDOVER,MD 20785. BALL AEROSP SYST GRP,BOULDER,CO 80304. RP Browning, VM (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 7 TC 0 Z9 0 U1 0 U2 4 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD MAY PY 1996 VL 36 IS 5 BP 391 EP 393 DI 10.1016/0011-2275(96)81110-6 PG 3 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA UG380 UT WOS:A1996UG38000010 ER PT J AU Bulbulian, R Heaney, JH Leake, CN Sucec, AA Sjoholm, NT AF Bulbulian, R Heaney, JH Leake, CN Sucec, AA Sjoholm, NT TI The effect of sleep deprivation and exercise load on isokinetic leg strength and endurance SO EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY LA English DT Article DE fatigue index; peak torque; fatigue; work ID FIBER COMPOSITION; SKELETAL-MUSCLE; PERFORMANCE AB Isokinetic leg strength and fatigue were measured in 24 male U.S. Marine Corps volunteers in a simulated sleep loss and unusually heavy work scenario. Knee extension and flexion peak torque (PT) were measured at three isokinetic speeds (1.57, 2.62 and 3.66 rad . s(-1)) followed by 45 consecutive maximal reciprocal contractions at 3.14 rad . s(-1) to measure fatigue index (FI). All subjects were retested 2 days later following 30-h sleep deprivation (SD). The exercise group (n = 12) spent 25 1-h sessions performing computer tasks, filling out questionnaires and walked 1.61 km with a 50% gross body mass pack load, during each of the 25 sessions. The control group (n = 12) did likewise but did not exercise. Repeated measures ANOVA indicated that flexion PT at 1.57 rad . s(-1) decreases (P < 0.013) after SD. Exercise did not affect FI but did decrease PT. It was concluded that carrying a 50% load produces decrements in PT for both extension and flexion but more so for flexion. SD affected PT but had no effect on FI. C1 UNIV KENTUCKY,EXERCISE PHYSIOL LAB,LEXINGTON,KY 40506. USN,HLTH RES CTR,SAN DIEGO,CA 92186. NR 23 TC 25 Z9 25 U1 1 U2 12 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0301-5548 J9 EUR J APPL PHYSIOL O JI Eur. J. Appl. Physiol. Occup. Physiol. PD MAY PY 1996 VL 73 IS 3-4 BP 273 EP 277 DI 10.1007/BF02425487 PG 5 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA UP585 UT WOS:A1996UP58500012 PM 8781857 ER PT J AU McCarthy, DD Luzum, BJ AF McCarthy, DD Luzum, BJ TI Path of the mean rotational pole from 1899 to 1994 SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE Earth's rotation; geodynamics ID LATITUDE SERVICE DATA; EARTHS ROTATION; PLEISTOCENE DEGLACIATION; GRAVITATIONAL-FIELD; MOTION; ICE AB Historical sources of polar motion are analysed together with modern data in order to compile a set of coordinates of the mean pole in a reference system consistent with that of the International Earth Rotation Service. The trend and quasi-periodic motion of the pole are investigated, and we find that the rotational pole appears to be moving at the rate of 0.333 arcsec century(-1) in the direction of 75.0 degrees west longitude. Modern data also appear to be consistent with the possible existence of very low-frequency periodic motion (Markowitz wobble). RP USN OBSERV, WASHINGTON, DC 20392 USA. NR 37 TC 54 Z9 57 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0956-540X EI 1365-246X J9 GEOPHYS J INT JI Geophys. J. Int. PD MAY PY 1996 VL 125 IS 2 BP 623 EP 629 DI 10.1111/j.1365-246X.1996.tb00024.x PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UH536 UT WOS:A1996UH53600024 ER PT J AU Lockette, W Kirkland, K Farrow, S AF Lockette, W Kirkland, K Farrow, S TI alpha(2)-Adrenergic agonists increase cellular lactate efflux SO HYPERTENSION LA English DT Article DE blood vessels; Na,K-ATPase; receptors, adrenergic; diabetes mellitus; temperature; clonidine; polymorphism (genetics) ID GLUCOSE-INDUCED THERMOGENESIS; PERFUSED RAT HINDLIMB; INSULIN RESISTANCE; HUMANS; METABOLISM; MUSCLE AB We reported previously that genetic polymorphisms of the alpha(2)-adrenergic receptor are associated with hyperinsulinemia, diabetes mellitus, and hypertension in blacks. The evolutionary driving force for maintaining such deleterious mutations in the black population is unknown. Recognizing that vascular alpha(2)-adrenergic receptors mediate cold-induced vasoconstriction and that temperature maintenance is a primary thrust of cellular metabolism, we postulated that vascular alpha(2)-adrenergic receptors contribute significantly to metabolic heat generation in homeotherms such as humans. Using aerobic lactate production as an indicator of thermogenesis, we measured metabolic heat produc lion in HT29 cells that expressed the gene encoding human vascular alpha(2)-adrenergic receptors. Epinephrine, an alpha(2)-adrenergic receptor agonist, increased net lactate efflux from 226+/-20 to 280+/-20 nmol/min (mean+/-SE) (P=.06). Clonidine, a more specific alpha(2)-adrenergic agonist, increased lactate efflux from 110+/-6 to 156+/-8 nmol/min (P<.01). Similarly, in the presence of physiological concentrations of glucose (5.5 mmol/L), insulin increased lactate production from 123+/-6 to 175+/-10 nmolimin (P<.01). Because differences in aerobic glycolysis may also explain the heat intolerance and abnormal fuel homeostasis found in genetically hypertensive rats, we also measured lactate production in cultured vascular smooth muscle cells isolated from stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive control Wistar-Kyoto rats (WKY). Vascular smooth muscle cells from SHRSP had significantly greater lactate efflux compared with cells from normotensive WKY (296+/-4 versus 172+/-2 nmol/min, P<.001). These differences were not due to abnormalities in glucose uptake, as lactate efflux was greater in SHRSP cells compared with WKY cells when dextrose was replaced with equimolar concentrations of fructose (230+/-6 versus 138+/-2 nmol/min, P<.001). alpha(2)-Adrenergic agonists increase lactate efflux in HT29 cells, and abnormalities in vascular smooth muscle lactate metabolism in genetically hypertensive rats is independent of altered glucose uptake. These data provide support for our hypothesis that balanced polymorphisms of the alpha(2)-adrenegic receptor could offer protection against cold stress by increasing the thermogenic response associated with aerobic lactate production. C1 VET ADM MED CTR,ALLEN PK,MI 48101. UNIV MICHIGAN,SCH MED,ANN ARBOR,MI. USN,HLTH RES CTR,SAN DIEGO,CA 92152. RP Lockette, W (reprint author), WAYNE STATE UNIV,SCH MED,HLTH CTR 4H,DIV ENDOCRINOL,4201 ST ANTOINE,DETROIT,MI 48201, USA. FU NHLBI NIH HHS [HL-50849] NR 28 TC 2 Z9 2 U1 0 U2 1 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 0194-911X J9 HYPERTENSION JI Hypertension PD MAY PY 1996 VL 27 IS 5 BP 1104 EP 1107 PG 4 WC Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA UJ747 UT WOS:A1996UJ74700011 PM 8621203 ER PT J AU Orndorff, CM Egan, CJ AF Orndorff, CM Egan, CJ TI Electric propulsion: Fleet readiness at affordable costs SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB The successful development and demonstration of the Al-AgO primary battery system dramatically demonstrated the viability of electric power plants for torpedo propulsion. Present efforts are focused on the development and demonstration of very low cost, quiet, high performance, safe, environmentally compatible, rechargeable batteries for heavyweight and lightweight torpedoes and tactical-sized UUVs. Electric power plants consisting of a rechargeable battery and a high reliability motor must be affordable to own and operate and enable turn-around without teardown for today's Fleet assets. RP Orndorff, CM (reprint author), USN,UNDERSEA WARFARE CTR,DIV NEWPORT,NEWPORT,RI 02841, USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD MAY PY 1996 VL 11 IS 5 BP 27 EP 31 DI 10.1109/62.494185 PG 5 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA UK298 UT WOS:A1996UK29800008 ER PT J AU Edelblute, DJ AF Edelblute, DJ TI Noncircularity SO IEEE SIGNAL PROCESSING LETTERS LA English DT Article AB This letter examines the second-order noncircular properties of Fourier coefficients that are estimated from a time stationary sampled sequence, If X(m) = (1/root M) Sigma(n=0)(M-1) x(n)exp(i2 pi mn/M), where x(n) is a time stationary data sequence, then the noncircular character of X(m) is shown by E[X(2)(m)] = 2A(m)csc(2 pi/M)exp(i2 pi m/M), where A(m) is the sine transform of the autocorrelation function of x(n). The signal processing implications of this are not yet clear, but it appears that it could degrade the performance of a detector by as much as 1.5 dB. RP Edelblute, DJ (reprint author), USN,COMMAND CONTROL & OCEAN SURVEILLANCE CTR,RES DEV TEST & EVALUAT DIV,SAN DIEGO,CA 92152, USA. NR 2 TC 3 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1070-9908 J9 IEEE SIGNAL PROC LET JI IEEE Signal Process. Lett. PD MAY PY 1996 VL 3 IS 5 BP 156 EP 157 DI 10.1109/97.491660 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA UK294 UT WOS:A1996UK29400008 ER PT J AU Kirby, J AF Kirby, J TI Architecture? Design? Debating classifications SO IEEE SOFTWARE LA English DT Letter RP Kirby, J (reprint author), USN,RES LAB,CODE 5546,4555 OVERLOOK AVE SW,WASHINGTON,DC 20375, 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 SN 0740-7459 J9 IEEE SOFTWARE JI IEEE Softw. PD MAY PY 1996 VL 13 IS 3 BP 10 EP & PG 2 WC Computer Science, Software Engineering SC Computer Science GA UH514 UT WOS:A1996UH51400004 ER PT J AU Sletten, MA Trizna, DB Hansen, JP AF Sletten, MA Trizna, DB Hansen, JP TI Ultrawide-band radar observations of multipath propagation over the sea surface SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article AB An ultrawide-band radar system centered at 10 GHz has been developed for sea-scatter research and was recently deployed on a research pier in the North Atlantic, The radar is based on a time-domain reflectometer module for a sampling oscilloscope, Using transient excitation of a traveling wave-tube amplifier, the system generates 200-ps wide pulses with a 10-GHz center frequency and a peak power of approximately 1 KW, The resulting range resolution is approximately 3 cm. The system was used to investigate low-grazing angle, multipath effects in the ocean environment using a trihedral corner reflector, mounted 45 cm above the water surface. The ultrahigh-range resolution of the system allows spatial separation of the direct and indirect echoes from the trihedral, In addition, a comparison of the indirect vertically- (VV) and horizontally- (HH) polarized echoes illustrates the effects of Brewster angle damping, The implications of these effects for sea-clutter statistics are briefly discussed. RP Sletten, MA (reprint author), USN, RES LAB, CODE 7255, WASHINGTON, DC 20375 USA. NR 15 TC 35 Z9 37 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD MAY PY 1996 VL 44 IS 5 BP 646 EP 651 DI 10.1109/8.496249 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA UJ956 UT WOS:A1996UJ95600006 ER PT J AU Sellami, L Newcomb, RW AF Sellami, L Newcomb, RW TI Synthesis of ARMA filters by real lossless digital lattices SO IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-ANALOG AND DIGITAL SIGNAL PROCESSING LA English DT Article ID REALIZATION AB A new method is presented to obtain degree-one or real degree-two transfer scattering matrices of two-port lossless lattice filters through the use of complex Richard's function extractions for the minimum degree cascade synthesis of real, stable, single-input, single-output ARMA (n, m) filters from the transfer function or the input reflection coefficient, The method relies on a four-step Richard's function extraction where two steps are used for reducing the degree of the transfer function and two for obtaining real lattices, We treat the cases where the zeros of transmission are inside and outside the unit circle but not on the unit circle. C1 UNIV MARYLAND,DEPT ELECT ENGN,MICROSYST LAB,COLLEGE PK,MD 20742. RP Sellami, L (reprint author), USN ACAD,DEPT ELECT ENGN,ANNAPOLIS,MD 21401, USA. NR 8 TC 7 Z9 7 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1057-7130 J9 IEEE T CIRCUITS-II JI IEEE Trans. Circuits Syst. II-Analog Digit. Signal Process. PD MAY PY 1996 VL 43 IS 5 BP 379 EP 386 DI 10.1109/82.494388 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA UN278 UT WOS:A1996UN27800004 ER PT J AU Fargues, MP Brown, DW AF Fargues, MP Brown, DW TI Hands-on exposure to signal processing concepts using the SPC toolbox SO IEEE TRANSACTIONS ON EDUCATION LA English DT Article AB We present an interactive software package developed to complement and facilitate the teaching of digital signal processing (DSP) concepts in various courses. The Signal Processing and Communications (SPC) software takes advantage of graphical user interface (GUI) capabilities contained in MAT-LAB(R). SPC is a window-based, user-friendly tool that allows users to develop digital filters, analyze signals, and easily design basic signal modeling tools without requiring the user to have strong coding abilities or be very familiar with MATLAB. To illustrate how SPC can be used in the classroom, we present applications of the SFC Toolbox that were used in two courses at the Naval Postgraduate School-Discrete System and Digital Signal Processing. RP Fargues, MP (reprint author), USN,POSTGRAD SCH,DEPT ELECT & COMP ENGN,MONTEREY,CA 93943, USA. NR 6 TC 2 Z9 2 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9359 J9 IEEE T EDUC JI IEEE Trans. Educ. PD MAY PY 1996 VL 39 IS 2 BP 192 EP 197 DI 10.1109/13.502066 PG 6 WC Education, Scientific Disciplines; Engineering, Electrical & Electronic SC Education & Educational Research; Engineering GA UM429 UT WOS:A1996UM42900014 ER PT J AU Trizna, DB Carlson, DJ AF Trizna, DB Carlson, DJ TI Studies of dual polarized low grazing angle radar sea scatter in nearshore regions SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID SURFACE; SLICKS AB We report on experiments featuring horizontally (HH) and vertically (VV) polarized X-band marine radar sea scatter imagery in the coastal environments of Bermuda and La Jolla, under light to moderate winds and the absence of long gravity waves. These conditions allowed the study of fundamental scattering mechanisms from small scale roughness and short waves of a few meters wavelength or less, shorter than the radar pulse. While a large fraction of radar data collected revealed the presence of slick bands, we analyze here the radar echo of ambient background outside of the slicks. Sea scatter data were digitally recorded for 360 degrees azimuthal coverage for grazing angles between 1-3.5 degrees, and were converted to normalized radar cross section (NRCS or sigma(o)) images. The HH and VV polarizations show quite different spatial texture, with HH exhibiting a discrete character and VV being more nearly spatially homogeneous. Grazing angle dependencies are different for HH and VV: upwind-downwind differences of mean NRCS show ratios of just 4-6 dB for VV, but are equal or greater than the 16-dB noise-imposed limit for HH for the low wind conditions. HH NRCS grazing angle characteristics are shown tb correlate with biological activity indicators of the coastal waters, with a fourth power dependence in relatively unproductive waters, to a nearly quadratic in productive waters. Arguments are presented that suggest different scattering mechanisms for the two polarizations: evenly distributed Bragg scatter patches for VV and scatter from small asymmetric bore features for HH. A multipath illumination model for small bore features is outlined, and scale sizes for the small scale breakers inferred from the experimental results presented here are between 2 and 4 cm in height, with crest widths between 24 and 48 cm. C1 UCAR,NOAA,BOULDER,CO 80301. RP Trizna, DB (reprint author), USN,RES LAB,REMOTE SENSING DIV,WASHINGTON,DC 20375, USA. NR 15 TC 56 Z9 59 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD MAY PY 1996 VL 34 IS 3 BP 747 EP 757 DI 10.1109/36.499754 PG 11 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA UM314 UT WOS:A1996UM31400015 ER PT J AU Ainsleigh, PL Chui, CK AF Ainsleigh, PL Chui, CK TI A B-wavelet-based noise-reduction algorithm SO IEEE TRANSACTIONS ON SIGNAL PROCESSING LA English DT Letter AB A wavelet-based method is introduced for removing structured noise (e.g., impulsive spikes or unwanted harmonic components) from data. For this type of noise, the time- and frequency-localization capabilities of wavelets provide better noise detection and less signal distortion than direct filtering of data, The procedure is applied to time-series data with impulsive noise and transfer-function data with multipath interference. C1 TEXAS A&M UNIV, CTR APPROXIMAT THEORY, COLLEGE STN, TX 77843 USA. RP Ainsleigh, PL (reprint author), USN, UNDERSEA WARFARE CTR, UNDERWATER SOUND REFERENCE DETACHMENT, ORLANDO, FL 32856 USA. NR 20 TC 9 Z9 9 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1053-587X J9 IEEE T SIGNAL PROCES JI IEEE Trans. Signal Process. PD MAY PY 1996 VL 44 IS 5 BP 1279 EP 1284 DI 10.1109/78.502342 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA UN484 UT WOS:A1996UN48400024 ER PT J AU Meadows, C AF Meadows, C TI Introduction to the special section SO IEEE TRANSACTIONS ON SOFTWARE ENGINEERING LA English DT Editorial Material RP Meadows, C (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 5 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 SN 0098-5589 J9 IEEE T SOFTWARE ENG JI IEEE Trans. Softw. Eng. PD MAY PY 1996 VL 22 IS 5 BP 281 EP 282 DI 10.1109/TSE.1996.502220 PG 2 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA UN030 UT WOS:A1996UN03000001 ER PT J AU Kang, MH Moskowitz, IS Lee, DC AF Kang, MH Moskowitz, IS Lee, DC TI A network pump SO IEEE TRANSACTIONS ON SOFTWARE ENGINEERING LA English DT Article; Proceedings Paper CT 1995 IEEE Symposium on Security and Privacy CY MAY 08-10, 1995 CL OAKLAND, CA SP IEEE Computer Soc, IEEE Computer Soc Tech Comm Secur & Privacy, Int Assoc Cryptol Res DE covert channel; flow control; gateway; information theory; router; security AB A designer of reliable multi-level secure (MLS) networks must consider covert channels and denial of service attacks in addition to traditional network performance measures such as throughput, fairness, and reliability. In this paper we show how to extend the NRL data Pump to a certain MLS network architecture in order to balance the requirements of congestion control, fairness, good performance, and reliability against those of minimal threats from covert channels and denial of service attacks. We back up our claims with simulation results. RP Kang, MH (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 26 TC 25 Z9 28 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0098-5589 J9 IEEE T SOFTWARE ENG JI IEEE Trans. Softw. Eng. PD MAY PY 1996 VL 22 IS 5 BP 329 EP 338 DI 10.1109/32.502225 PG 10 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA UN030 UT WOS:A1996UN03000006 ER PT J AU Powell, DJ Hayward, G AF Powell, DJ Hayward, G TI Flexible ultrasonic transducer arrays for nondestructive evaluation applications .2. Performance assessment of different array configurations SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article ID COMPOSITE AB This work describes a fundamental investigation into a new series of transducer array structures intended for those applications where surface conformity is desirable. The first objective is to consider which material combinations will offer flexibility, while at the same time maximize the electromechanical efficiency for operating into solid load media. In Part I of this work [1], a modeling strategy for flexible arrays was developed. This theoretical approach is employed in Part II to compare and assess different array structures for nondestructive evaluation (NDE) imaging applications. The array structures under consideration include multielement piezocomposite and piezopolymer arrays, and hybrid devices comprising piezocomposite transmitters with piezopolymer receivers. Experimental data are provided for a novel array configuration, comprising a separate piezocomposite transmitter coupled to a piezopolymer receiver, Good agreement is demonstrated between experimental and theoretical results. C1 USN,UNDERSEA WARFARE CTR,ORLANDO,FL 32806. RP Powell, DJ (reprint author), UNIV STRATHCLYDE,ULTRASON RES GRP,GLASGOW G1 1XW,LANARK,SCOTLAND. NR 6 TC 14 Z9 14 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD MAY PY 1996 VL 43 IS 3 BP 393 EP 402 DI 10.1109/58.489396 PG 10 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA UH299 UT WOS:A1996UH29900007 ER PT J AU Montgomery, RE Richard, C AF Montgomery, RE Richard, C TI A model for the hydrostatic pressure response of a 1-3 composite SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article AB An analytical model has been developed for predicting the mechanical response of a composite cylinder that is composed of a solid right circular cylinder of one material surrounded by a cylindrical tube composed of some other material. It is assumed that there is no slippage at the boundary between the two phases. The model employs, throughout, the exact equations of linear elasticity and, thus, provides a solution that is exact for the specific boundary conditions that are imposed. In this paper, the specific case of hydrostatic pressure applied to the surface of the composite cylinder is discussed. The model yields the displacement and stress fields throughout the entire structure. The model was verified by comparing the results with a finite element model at several surfaces and interfaces in the structure. The model can he readily applied to the analysis of passive composite structures as well as to some of the recent active materials such as 1-3 piezocomposites. C1 INST NATL SCI APPL,F-69621 VILLEURBANNE,FRANCE. RP Montgomery, RE (reprint author), USRD,NRL,ORLANDO,FL 32856, USA. NR 11 TC 4 Z9 4 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD MAY PY 1996 VL 43 IS 3 BP 457 EP 466 DI 10.1109/58.489405 PG 10 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA UH299 UT WOS:A1996UH29900016 ER PT J AU Wiest, DL Ashe, JM Abe, R Bolen, JB Singer, A AF Wiest, DL Ashe, JM Abe, R Bolen, JB Singer, A TI TCR activation of ZAP70 is impaired in CD4(+)CD8(+) thymocytes as a consequence of intrathymic interactions that diminish available p56(lck) SO IMMUNITY LA English DT Article ID T-CELL RECEPTOR; TYROSINE-PROTEIN-KINASE; IMMATURE CD4+CD8+ THYMOCYTES; ANTIGEN RECEPTOR; MICE LACKING; MONOCLONAL-ANTIBODY; ZETA-CHAIN; LYMPHOCYTES-T; CD8 LINEAGE; EXPRESSION AB The fate of developing CD4(+)CD8(+) thymocytes is determined by signals transduced through surface TCR complexes. Here, we report that cross-linking of TCR on CD4(+)CD8(+) thymocytes fails to activate ZAP70 protein tyrosine kinase and fails to initiate downstream signaling events, unless the TCR are coaggregated with surface coreceptor molecules. TCR signaling in CD4(+)CD8(+) thymocytes is impaired because the number of available p56(lck) molecules is diminished by intrathymic CD4-1a interactions that initially activate p56(lck) molecules, which are subsequently degraded. As a consequence of intrathymic CD4-1a interactions, TCR zeta chains are initially phosphorylated to recruit ZAP70 molecules, but the recruited ZAP70 molecules are not subsequently phosphorylated, resulting in TCR complexes that are stably associated with inactive ZAP70 molecules. Thus, intrathymic interactions that diminish p56(lck) regulate TCR signaling thresholds and affect TCR structure in developing CD4(+)CD8(+) thymocytes. C1 USN,MED RES INST,IMMUNE CELL BIOL DEPT,BETHESDA,MD 20889. DNAX RES INST MOLEC & CELLULAR BIOL INC,DEPT CELLULAR SIGNALING,PALO ALTO,CA 94304. RP Wiest, DL (reprint author), NCI,EXPTL IMMUNOL BRANCH,NIH,BLDG 10,BETHESDA,MD 20892, USA. OI Wiest, David/0000-0002-0792-3188 NR 56 TC 71 Z9 71 U1 0 U2 0 PU CELL PRESS PI CAMBRIDGE PA 1050 MASSACHUSETTES AVE, CIRCULATION DEPT, CAMBRIDGE, MA 02138 SN 1074-7613 J9 IMMUNITY JI Immunity PD MAY PY 1996 VL 4 IS 5 BP 495 EP 504 DI 10.1016/S1074-7613(00)80415-X PG 10 WC Immunology SC Immunology GA UM678 UT WOS:A1996UM67800008 PM 8630734 ER PT J AU Gorski, JJ Bernard, PS AF Gorski, JJ Bernard, PS TI Modeling of the turbulent enstrophy equation SO INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE LA English DT Article ID BOUNDED ENERGY-STATES; NEAR-WALL TURBULENCE; LOW REYNOLDS-NUMBER; CHANNEL FLOW; SHEAR FLOWS; STRESS; PREDICTION; CLOSURES; FIELD; LAYER AB Though the turbulent enstrophy and turbulent dissipation rate equations have many similarities, the former lacks expressions involving the pressure whose modeling has proved to be largely intractable. Moreover, it will be shown here that several of the production terms in the enstrophy equation may be analyzed through formal vorticity transport analysis. The result is a more careful accounting of production effects than has thus far been possible in the dissipation rate equation. When used with the conventional dissipation model, the new production terms significantly affect the enstrophy equation budget, but not the predicted mean velocity and turbulent kinetic energy. Thus, improved modeling of the enstrophy dissipation term is also necessary before the new production terms can have a beneficial impact on the computed flow fields. For low Reynolds number channel flow, a disspation model is constructed which demonstrates how accurate representations of the individual terms in the enstrophy balance can lead to improved predictions of turbulent quantities. C1 UNIV MARYLAND,DEPT MECH ENGN,COLLEGE PK,MD 20742. UNIV MARYLAND,INST ADV COMP STUDIES,COLLEGE PK,MD 20742. RP Gorski, JJ (reprint author), USN,CTR SURFACE WARFARE,CADEROCK DIV,BETHESDA,MD 20084, USA. NR 36 TC 2 Z9 2 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-7225 J9 INT J ENG SCI JI Int. J. Eng. Sci. PD MAY PY 1996 VL 34 IS 6 BP 699 EP 714 DI 10.1016/0020-7225(95)00106-9 PG 16 WC Engineering, Multidisciplinary SC Engineering GA UP258 UT WOS:A1996UP25800006 ER PT J AU Robinson, GE AF Robinson, GE TI Hamas; From religious salvation to political transformation: The rise of Hamas in Palestinian society - Ahmad,HH SO INTERNATIONAL JOURNAL OF MIDDLE EAST STUDIES LA English DT Book Review RP Robinson, GE (reprint author), USN,POSTGRAD SCH,DEPT NATL SECUR AFFAIRS,MONTEREY,CA 93940, USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0020-7438 J9 INT J MIDDLE E STUD JI Int. J. Middle East Stud. PD MAY PY 1996 VL 28 IS 2 BP 273 EP 275 PG 3 WC Area Studies SC Area Studies GA UH988 UT WOS:A1996UH98800018 ER PT J AU Karle, IL Gurunath, R Prasad, S Rao, RB Balaram, P AF Karle, IL Gurunath, R Prasad, S Rao, RB Balaram, P TI Crystal structures of a nonapeptide helix containing alpha,alpha-di-n-butylglycine (Dbg), Boc-Gly-Dbg-Ala-Val-Ala-Leu-Aib-Val-Leu-OMe SO INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH LA English DT Article DE alpha,alpha-di-n-butylglycine (Dbg); backbone conformational constraints; helical peptide; peptide conformation; peptide crystal structure; X-ray diffraction ID ALPHA-DIALKYLATED GLYCINES; AMINO-ACIDS; PEPTIDES; STEREOCHEMISTRY; DIETHYLGLYCINE; VERSATILITY; ABSORPTION; DESIGN AB Two crystals structures of a nonapeptide (anhydrous and hydrated) containing the amino acid residue alpha, alpha-di-n-butylglycyl, reveal a mixed 3(10)/alpha-helical conformation. Residues 1-7 adopt phi, psi values in the helical region, with Val(8) being appreciably distorted. The Dbg residue has phi, psi values of -40, -37 degrees and -46, -40 degrees in two crystals with the two butyl side chains mostly extended in each. Peptide molecules in the crystals pack into helical columns. The crystal parameters are C50H91N9O12, space group P2(1), with a = 9.789(1) Angstrom, b = 20.240(2) Angstrom, c = 15.998(3) Angstrom, beta = 103.27(1); Z = 2, R = 10.3% for 1945 data observed >3 sigma(F) and C50H91N9O12. 3H(2)O, space group P2(1), with a = 9.747(3) Angstrom, b = 21.002(8) Angstrom, c = 15.885(6) Angstrom, beta = 102.22(3)degrees, Z = 2, R = 13.6% for 2535 data observed >3 sigma(F). The observation of a helical conformation at Dbg suggests that the higher homologs in the alpha, alpha-dialkylated glycine series also have a tendency to stabilize peptide helices. (C) Munksgaard 1996. C1 INDIAN INST SCI,MOLEC BIOPHYS UNIT,BANGALORE 560012,KARNATAKA,INDIA. BANARAS HINDU UNIV,DEPT CHEM,VARANASI 221005,UTTAR PRADESH,INDIA. RP Karle, IL (reprint author), USN,RES LAB,STRUCT MATTER LAB,WASHINGTON,DC 20375, USA. RI Ramanathan, Gurunath/B-4757-2011 OI Ramanathan, Gurunath/0000-0003-4627-1677 FU NIGMS NIH HHS [GM30902] NR 30 TC 11 Z9 11 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0367-8377 J9 INT J PEPT PROT RES JI Int. J. Pept. Protein Res. PD MAY PY 1996 VL 47 IS 5 BP 376 EP 382 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UP358 UT WOS:A1996UP35800008 PM 8791161 ER PT J AU Brawley, SC Hobson, GV AF Brawley, SC Hobson, GV TI Airfoil design utilizing parallel processors SO JOURNAL OF AIRCRAFT LA English DT Article RP Brawley, SC (reprint author), USN,POSTGRAD SCH,DEPT AERONAUT & ASTRONAUT,MONTEREY,CA 93943, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD MAY-JUN PY 1996 VL 33 IS 3 BP 630 EP 632 DI 10.2514/3.46994 PG 3 WC Engineering, Aerospace SC Engineering GA UP198 UT WOS:A1996UP19800029 ER PT J AU Kelso, JM Keating, RM AF Kelso, JM Keating, RM TI Successful desensitization for treatment of a fixed drug eruption to allopurinol SO JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY LA English DT Article C1 USN,MED CTR,DEPT INTERNAL MED,DIV ALLERGY,SAN DIEGO,CA 92134. USN,MED CTR,DEPT INTERNAL MED,DIV RHEUMATOL,SAN DIEGO,CA 92134. RP Kelso, JM (reprint author), USN,MED CTR,DEPT CLIN INVEST,SAN DIEGO,CA 92134, USA. NR 6 TC 16 Z9 17 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 SN 0091-6749 J9 J ALLERGY CLIN IMMUN JI J. Allergy Clin. Immunol. PD MAY PY 1996 VL 97 IS 5 BP 1171 EP 1172 DI 10.1016/S0091-6749(96)70275-0 PG 2 WC Allergy; Immunology SC Allergy; Immunology GA UL261 UT WOS:A1996UL26100021 PM 8626998 ER PT J AU Tag, PM Peak, JE AF Tag, PM Peak, JE TI Machine learning of maritime fog forecast rules SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article AB In recent years, the field of artificial intelligence has contributed significantly to the science of meteorology, most notably in the now familiar form of expert systems. Expert systems have focused on rules or heuristics by establishing, in computer code, the reasoning process of a weather forecaster predicting, for example, thunderstorms or fog. In addition to the years of effort that goes into developing such a knowledge base is the time-consuming task of extracting such knowledge and experience from experts. In this paper, the induction of rules directly from meteorological data is explored-a process called machine learning. A commercial machine learning program, called C4.5, is applied to a meteorological problem, forecasting maritime fog, for which a reliable expert system has been previously developed. Two datasets are used: 1) weather ship observations originally used for testing and evaluating the expert system, and 2) buoy measurements taken off the coast of California. For both datasets, the rules produced by C4.5 are reasonable and make physical sense, thus demonstrating that an objective induction approach can reveal physical processes directly from data. For the ship database, the machine-generated rules are nor as accurate as those from the expert system but are still significantly better than persistence forecasts. For the buoy data, the forecast accuracies are very high, but only slightly superior to persistence. The results indicate that the machine learning approach is a viable tool for developing meteorological expertise, but only when applied to reliable data with sufficient cases of known outcome. Tn those instances when such databases are available, the use of machine learning can provide useful insight that otherwise might take considerable human analysis to produce. C1 COMP SCI CORP,MONTEREY,CA. RP Tag, PM (reprint author), USN,RES LAB,MONTEREY,CA 93943, USA. NR 22 TC 13 Z9 14 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD MAY PY 1996 VL 35 IS 5 BP 714 EP 724 DI 10.1175/1520-0450(1996)035<0714:MLOMFF>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ387 UT WOS:A1996UJ38700009 ER PT J AU Slakey, JB Hennrikus, WL AF Slakey, JB Hennrikus, WL TI Acquired thumb flexion contracture in children - Congenital trigger thumb SO JOURNAL OF BONE AND JOINT SURGERY-BRITISH VOLUME LA English DT Article AB We examined prospectively 4719 newborn infants to determine the congenital incidence of trigger thumb. No cases were found. Fifteen other children aged from 15 to 51 months had surgery for this condition. The anomaly had not been seen at birth and all thumbs presented with a flexion contracture without triggering. The condition is usually seen after birth as a flexion contracture of the interphalangeal joint. The term 'congenital' is a misnomer because patients acquire the deformity after birth. The term 'trigger' is inaccurate as most thumbs show a fixed-flexion contracture without triggering. We suggest that rather than 'congenital trigger thumb' a more appropriate description of this disorder is 'acquired thumb flexion contracture in children'. If the contracture persists after one year of age, treatment by dividing the A-1 pulley is simple and effective. C1 USN HOSP,DEPT ORTHOPAED SURG & CLIN INVEST,SAN DIEGO,CA 92134. NR 31 TC 36 Z9 39 U1 0 U2 0 PU BRITISH EDITORIAL SOC BONE JOINT SURGERY PI LONDON PA 22 BUCKINGHAM STREET, LONDON, ENGLAND WC2N 6ET SN 0301-620X J9 J BONE JOINT SURG BR JI J. Bone Joint Surg.-Br. Vol. PD MAY PY 1996 VL 78B IS 3 BP 481 EP 483 PG 3 WC Orthopedics; Surgery SC Orthopedics; Surgery GA UM461 UT WOS:A1996UM46100028 PM 8636191 ER PT J AU Beck, TJ Ruff, CB Mourtada, FA Shaffer, RA MaxwellWilliams, K Kao, GL Sartoris, DJ Brodine, S AF Beck, TJ Ruff, CB Mourtada, FA Shaffer, RA MaxwellWilliams, K Kao, GL Sartoris, DJ Brodine, S TI Dual-energy X-ray absorptiometry derived structural geometry for stress fracture prediction in male US Marine Corps recruits SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Article ID BONE-MINERAL DATA; SEX-DIFFERENCES; FEMORAL-NECK; RISK FACTOR; INERTIA; ADULTS; MOMENT; FEMUR; TIBIA AB A total of 626 U.S. male Marine Corps recruits underwent anthropometric measurements and dual-energy X-ray absorptiometry (DXA) scans of the femoral midshaft and the distal third of the tibia prior to a 12 week physical training program, Conventionally obtained frontal plane DXA scan data were used to measure the bone mineral density (BMD) as well as to derive the cross-sectional area, moment of inertia, section modulus, and bone width in the femur, tibia, and fibula, During training, 23 recruits (3.7%) presented with a total of 27 radiologically confirmed stress fractures in various locations in the lower extremity, After excluding 16 cases of shin splints, periostitis, and other stress reactions that did not meet fracture definition criteria, we compared anthropometric and bone structural geometry measurements between fracture cases and the remaining 587 normals, There was no significant difference in age (p = 0.8), femur length (p = 0.2), pelvic width (p = 0.08), and knee width at the femoral condyles (p = 0.06), but fracture cases were shorter (p = 0.01), lighter (p = 0.0006), and smaller in most anthropometric girth dimensions (p < 0.04), Fracture case bone cross-sectional areas (p < 0.001), moments of inertia (p < 0.001), section moduli (p < 0.001), and widths (p < 0.001) as well as BMD (p < 0.03) were significantly smaller in the tibia and femur, After correcting for body weight differences, the tibia cross-sectional area (p = 0.03), section modulus (p = 0.05), and width (p = 0.03) remained significantly smaller in fracture subjects, We conclude that both small body weight and small diaphyseal dimensions relative to body weight are factors predisposing to the development of stress fractures in this population, These results suggest that bone structural geometry measurements derived from DXA data may provide a simple noninvasive methodology for assessing the risk of stress fracture. C1 JOHNS HOPKINS UNIV,SCH MED,DEPT RADIOL & RADIOL SCI,BALTIMORE,MD. JOHNS HOPKINS UNIV,SCH MED,DEPT ANAT & CELL BIOL,BALTIMORE,MD. JOHNS HOPKINS UNIV,SCH MED,DEPT ORTHOPAED SURG,BALTIMORE,MD. USN,HLTH RES CTR,DEPT EPIDEMIOL & HLTH SCI,SAN DIEGO,CA 92152. UNIV CALIF SAN DIEGO,MED CTR,DEPT RADIOL,SAN DIEGO,CA 92103. NR 30 TC 116 Z9 116 U1 0 U2 2 PU BLACKWELL SCIENCE INC PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD MAY PY 1996 VL 11 IS 5 BP 645 EP 653 PG 9 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA UG290 UT WOS:A1996UG29000011 PM 9157779 ER PT J AU Tam, DA Myer, EC AF Tam, DA Myer, EC TI Vitamin K-dependent coagulopathy in a child receiving anticonvulsant therapy SO JOURNAL OF CHILD NEUROLOGY LA English DT Article ID VALPROIC ACID; SODIUM VALPROATE; CARBOXYLASE; DISEASE C1 VIRGINIA COMMONWEALTH UNIV,MED COLL VIRGINIA,DIV CHILD NEUROL,RICHMOND,VA 23298. RP Tam, DA (reprint author), USN,MED CTR,DEPT PEDIAT,SAN DIEGO,CA 92152, USA. NR 28 TC 4 Z9 4 U1 0 U2 0 PU DECKER PERIODICALS INC PI HAMILTON PA 4 HUGHSON STREET SOUTH PO BOX 620, LCD 1, HAMILTON ON L8N 3K7, CANADA SN 0883-0738 J9 J CHILD NEUROL JI J. Child Neurol. PD MAY PY 1996 VL 11 IS 3 BP 244 EP 246 PG 3 WC Clinical Neurology; Pediatrics SC Neurosciences & Neurology; Pediatrics GA UK384 UT WOS:A1996UK38400017 PM 8734031 ER PT J AU Mohran, ZS Guerry, P Lior, H Murphy, JR ElGendy, AM Mikhail, MM Oyofo, BA AF Mohran, ZS Guerry, P Lior, H Murphy, JR ElGendy, AM Mikhail, MM Oyofo, BA TI Restriction fragment length polymorphism of flagellin genes of Campylobacter jejuni and/or C-coli isolates from Egypt SO JOURNAL OF CLINICAL MICROBIOLOGY LA English DT Article ID ANTIGENIC VARIATION; IMMUNE-RESPONSE; COLONIZATION; MUCUS AB The conservation of flagellin genes from thermophilic Campylobacter spp. strains isolated in Egypt was evaluated by a restriction fragment length polymorphism (RFLP) assay, The flaA and flaB genes were amplified from 59 independent clinical isolates and digested with EcoRI and PstI, and the resulting patterns were compared with each other and with previously described RFLP groups. The results indicate that the isolates fell into 14 groups for flaA and 11 groups for flaB, 9 of which have been described, and that considerable genetic variability exists among isolates belonging to the same LIO serogroup. In most cases, the flaB gene displayed the same RFLP pattern as that of the flaA gene of the same strain, although some variability was observed. The data suggest that more variability of flagellin genes exists within the LIO serogroups common to Campylobacter field isolates from Egypt than has previously been reported for North American isolates. C1 USN,MED RES INST,BETHESDA,MD. LAB CTR DIS CONTROL,OTTAWA,ON K1A 0L2,CANADA. UNIV TEXAS,CTR INFECT DIS,HOUSTON,TX. RP Mohran, ZS (reprint author), USN,MED RES UNIT 3,PSC 452 BOX 5000,CODE 101F,FPO,AE 09835, USA. NR 24 TC 16 Z9 19 U1 0 U2 2 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0095-1137 J9 J CLIN MICROBIOL JI J. Clin. Microbiol. PD MAY PY 1996 VL 34 IS 5 BP 1216 EP 1219 PG 4 WC Microbiology SC Microbiology GA UF570 UT WOS:A1996UF57000033 PM 8727905 ER PT J AU Brook, I AF Brook, I TI Veillonella infections in children SO JOURNAL OF CLINICAL MICROBIOLOGY LA English DT Article ID ANAEROBIC BACTEREMIA; PARVULA AB From 1974 to 1994, 2,033 specimens from children were submitted for cultures for anaerobic bacteria. Eighty-three Veillonella spp, were recovered from 83 children (4%), Most Veillonella species were recovered from abscesses, aspiration pneumonias, burns, bites, and sinuses. The infections were polymicrobial in 79 (95%) patients, but in 4 (5%) patients, Veillonella species were recovered in pure culture, The predisposing conditions associated with the recovery of these organisms were previous surgery, malignancy, steroid therapy, foreign body, and immunodeficiency, These data illustrate that Veillonella spp, are found infrequently in children, mostly in association with mixed infections, and are recovered mixed with mouth and bowel flora. C1 USN HOSP,DEPT PEDIAT,BETHESDA,MD. GEORGETOWN UNIV,SCH MED,DEPT PEDIAT,WASHINGTON,DC 20007. NR 21 TC 26 Z9 27 U1 0 U2 2 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0095-1137 J9 J CLIN MICROBIOL JI J. Clin. Microbiol. PD MAY PY 1996 VL 34 IS 5 BP 1283 EP 1285 PG 3 WC Microbiology SC Microbiology GA UF570 UT WOS:A1996UF57000048 PM 8727920 ER PT J AU Kowalski, MP Cruddace, RG Seely, JF Rife, JC Hunter, WR Barbee, TW AF Kowalski, MP Cruddace, RG Seely, JF Rife, JC Hunter, WR Barbee, TW TI The EUV performance of an ion-etched blazed diffraction grating SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 11th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-11 Conference) CY AUG 27-SEP 01, 1995 CL RIKKYO UNIV, TOKYO, JAPAN SP Phys Soc Japan, Chem Soc Japan, Japanese Soc Appl Phys, Spectroscop Soc Japan, Biophys Soc Japan, Vacuum Soc Japan, Japan Soc Promot Sci, Federat Econ Org, Commemorat Assoc Japan World Exposit 1970, JAERI RIKEN Spring 9 Project Team, Unoue Fdn Sci, Ciba Geigy Fdn Japan Promot Sci, Murata Sci Fdn, Asahi Glass Fdn, Shimadzu Sci Fdn, Watanabe Mem Fdn Adv Technol, Nippon Sheet Glass Fdn Mat Sci & Engn, Osaka Sci & Technol Ctr HO RIKKYO UNIV ID MULTILAYER; OPERATION; RANGE AB A spherical holographic ion-etched diffraction grating with low-blaze angle has been purchased for the purpose of vendor evaluation. We present the results of surface measurements made on the bare grating substrate using an atomic force microscope. The efficiency of the grating at grazing incidence and at EW wavelengths was measured using a synchrotron light source. After coating the grating with a multilayer, the normal incidence efficiency was measured. The results of these measurements are compared to those obtained from samples from other vendors. C1 SFA INC,LANDOVER,MD 20785. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Kowalski, MP (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD MAY PY 1996 VL 80 BP 473 EP 476 DI 10.1016/0368-2048(96)03019-8 PG 4 WC Spectroscopy SC Spectroscopy GA VA962 UT WOS:A1996VA96200112 ER PT J AU Berger, H LaRosa, S Terrasi, A Marsi, M Collins, I Kelley, RJ Quitmann, C Ma, JA Kendziora, C Skelton, E Onellion, M Margaritondo, G AF Berger, H LaRosa, S Terrasi, A Marsi, M Collins, I Kelley, RJ Quitmann, C Ma, JA Kendziora, C Skelton, E Onellion, M Margaritondo, G TI Progress in understanding VUV photoemission in low-dimensionality systems SO JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA LA English DT Article; Proceedings Paper CT 11th International Conference on Vacuum Ultraviolet Radiation Physics (VUV-11 Conference) CY AUG 27-SEP 01, 1995 CL RIKKYO UNIV, TOKYO, JAPAN SP Phys Soc Japan, Chem Soc Japan, Japanese Soc Appl Phys, Spectroscop Soc Japan, Biophys Soc Japan, Vacuum Soc Japan, Japan Soc Promot Sci, Federat Econ Org, Commemorat Assoc Japan World Exposit 1970, JAERI RIKEN Spring 9 Project Team, Unoue Fdn Sci, Ciba Geigy Fdn Japan Promot Sci, Murata Sci Fdn, Asahi Glass Fdn, Shimadzu Sci Fdn, Watanabe Mem Fdn Adv Technol, Nippon Sheet Glass Fdn Mat Sci & Engn, Osaka Sci & Technol Ctr HO RIKKYO UNIV ID CU-O; GAP AB High-resolution angle-resolved photoemission and core-level photoemission measurements were performed on single crystal samples of the quasi-one-dimensional material (TaSe4)(2)I and the cuprate superconductor Bi2Sr2CaCu2O8+x. Resistivity measurements were performed on both materials. X-ray diffraction, transmission electron microscopy (TEM), and AC susceptibility measurements were performed on the cuprate samples. The data indicate that photoemission studies provide key information in understanding the physics issues of both materials. C1 UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706. USN,RES LAB,DIV CONDENSED MATTER & RADIAT SCI,WASHINGTON,DC 20375. RI Quitmann, Christoph/A-7047-2008; Margaritondo, Giorgio/B-1367-2008; OI Terrasi, Antonio/0000-0002-0291-6923 NR 20 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0368-2048 J9 J ELECTRON SPECTROSC JI J. Electron Spectrosc. Relat. Phenom. PD MAY PY 1996 VL 78 BP 431 EP 436 DI 10.1016/S0368-2048(96)80116-2 PG 6 WC Spectroscopy SC Spectroscopy GA UT322 UT WOS:A1996UT32200102 ER PT J AU Carlos, WE Glaser, ER Kennedy, TA Nakamura, S AF Carlos, WE Glaser, ER Kennedy, TA Nakamura, S TI Magnetic resonance studies of GaN based light emitting diodes SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Electronic Materials Conference CY JUN 21-23, 1995 CL CHARLOTTESVILLE, VA DE electroluminescence; electron spin resonance; GaN; light emitting diodes (LEDs) ID SPIN-DEPENDENT RECOMBINATION; ELECTROLUMINESCENCE; GROWTH AB We report the application of electrical detection of magnetic resonance (EDMR) and electroluminescence detection of magnetic resonance (ELDMR) to study the recombination processes in InGaN/AlGaN double heterostructure p-nj unctions. These techniques are especially well suited to the problems of defects in device structures in that they are much more sensitive than conventional paramagnetic resonance and are responsive to only those defects involved in the electrooptical properties of the structure. One resonance is observed at g approximate to 2.00 and is identified as a Zn-related acceptor trap in the InGaN layer. A second resonance with g approximate to 1.99 is identified as a deep donor. C1 NICHIA CHEM IND LTD,TOKUSHIMA 774,JAPAN. RP Carlos, WE (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 23 TC 3 Z9 3 U1 2 U2 3 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD MAY PY 1996 VL 25 IS 5 BP 851 EP 854 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA UJ099 UT WOS:A1996UJ09900014 ER PT J AU Gardner, J Rao, MV Holland, OW Kelner, G Simons, DS Chi, PH Andrews, JM Kretchmer, J Ghezzo, M AF Gardner, J Rao, MV Holland, OW Kelner, G Simons, DS Chi, PH Andrews, JM Kretchmer, J Ghezzo, M TI Elevated temperature nitrogen implants in 6H-SiC SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT Electronic Materials Conference CY JUN 21-23, 1995 CL CHARLOTTESVILLE, VA DE electrical activation; ion implantation; nitrogen; p-n junction diode; secondary ion mass spectrometry; silicon carbide ID BETA SILICON-CARBIDE; ELECTRICAL-PROPERTIES; JUNCTION DIODES AB Elevated temperature (700 degrees C)N ion implantations were performed into 6H-SiC in the energy range of 50 keV-4 MeV. By analyzing the as-implanted depth distributions, the range statistics of the N+ in 6H-SiC have been established over this energy range. Annealing at 1500 and 1600 degrees C for 15 min resulted in Rutherford backscattering spectrometry scattering yields at the virgin crystal level, indicating a good recovery of the crystalline quality of the material without any redistribution of the dopant. A maximum electron concentration of 2 x 10(19) cm(-3), at room temperature, has been measured even for high-dose implants. The p-n junction diodes made by N ion implantation into a p-type substrate have a forward turn-on voltage of 2.2 V, an ideality factor of 1.90, and a reverse breakdown voltage of 125 V with nA range leakage current for -10 V bias at room temperature. By probing many devices on the same substrate we found uniform forward and reverse characteristics across the crystal. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. USN,RES LAB,WASHINGTON,DC 20375. NIST,GAITHERSBURG,MD 20899. NANTRON ASSOCIATES,ALEXANDRIA,VA 22306. GE CO,CORP RES & DEV,SCHENECTADY,NY 12301. RP Gardner, J (reprint author), GEORGE MASON UNIV,DEPT ELECT & COMP ENGN,FAIRFAX,VA 22030, USA. NR 32 TC 23 Z9 23 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD MAY PY 1996 VL 25 IS 5 BP 885 EP 892 PG 8 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA UJ099 UT WOS:A1996UJ09900020 ER PT J AU Gernandt, MN Urlaub, JJ AF Gernandt, MN Urlaub, JJ TI An introduction to the gel pen SO JOURNAL OF FORENSIC SCIENCES LA English DT Article DE forensic science; questioned documents; gel ink; dyestuffs; pigments AB A new ''class'' of writing ink, whose ink has new chemical features, is being introduced into the United States from Japan. The new ink is known as gel ink and it is water-based. It can be differentiated from the traditional water-based roller ball and porous tip class of writing inks by its chemical composition and physical properties. Gel inks differ from other water-based inks by the incorporation of colored pigments to give the inks a full range of colors without the use of colored dyestuffs commonly used in water-based inks. Other differences include gel ink's high viscosity, leading to the name ''gel ink.'' The gel pen is visually identifiable and different in appearance from other writing instruments by its clear outside barrel and fill tube, which contains the pigmented gel ink. The pen housing and fill tube is clear in order to display the actual color of ink. The plastic fill tube will be a larger diameter than the tube found in a ballpen and will contain a clear silicon grease plug. Gel inks are tested and differentiated from other writing inks by the same battery of tests used in the past. Nondestructively, gel pen writing can be visually examined for ink absorption into the paper fibers, color difference and overall line quality of the writing. Ultraviolet and infrared light examinations will also aid in differentiating gel inks from other writing inks. Destructive methods of testing gel ink may prove to be the most identifiable and demonstrative of all the available tests. Thin layer chromatography may be used to separate detectable components of inks. Gel inks that contain pigments and no dyestuffs for separation, will have a negative reaction in this area. The gel pen is a unique writing instrument because of the chemistry in the gel coupled with a new pen design. The water-based gel ink is environmentally friendly and permanent. These attributes may allow the gel pen a sizeable impact on the U.S. market. C1 FORMULABS INC,ESCONDIDO,CA 92025. RP Gernandt, MN (reprint author), USN,CRIMINAL INVEST SERV,REG FORENS LAB,3405 WELLES ST,SUITE 3,SAN DIEGO,CA 92136, USA. NR 3 TC 11 Z9 11 U1 2 U2 7 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0022-1198 J9 J FORENSIC SCI JI J. Forensic Sci. PD MAY PY 1996 VL 41 IS 3 BP 503 EP 504 PG 2 WC Medicine, Legal SC Legal Medicine GA UN366 UT WOS:A1996UN36600028 ER PT J AU Creamer, G DeLaHunt, P Gates, S Levenson, M AF Creamer, G DeLaHunt, P Gates, S Levenson, M TI Attitude determination and control of Clementine during lunar mapping SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID MANEUVERS; FEEDBACK AB The Clementine spacecraft, launched in early 1994, recently completed a two-month lunar mapping mission in which it recorded high-resolution images over the entire surface of the moon. The attitude determination and control subsystems developed for the mapping phase of the mission are described. The vehicle's attitude determination subsystem consisted of a simple fixed-gain Kalman filter, uncoupled about each spacecraft axis, combining rate inputs from two solid-state optical gyros and attitude inputs from two wide field-of-view star trackers. The attitude control subsystem consisted of a simple proportional-integral-derivative algorithm operating on quaternion and rate feedback signals to provide pointing, tracking, and slewing functions. The primary actuating devices were three reaction wheels used for feedback error compensation and 12 thrusters used for occasional momentum dumping. During lunar mapping the attitude determination and control subsystems maintained vehicle pointing to within a three-axis rss value of 0.05 deg. On-orbit results are provided from outputs of the attitude determination filter, the lunar nadir-tracking controller, and the large-angle slew generator. Additionally, results are provided from a novel inertia estimator, which utilized sensor outputs during two slew maneuvers. C1 USN,RES LAB,SPACECRAFT ATTITUDE CONTROL SECT,WASHINGTON,DC 20375. RP Creamer, G (reprint author), SWALES & ASSOCIATES INC,BELTSVILLE,MD 20705, USA. NR 8 TC 18 Z9 20 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAY-JUN PY 1996 VL 19 IS 3 BP 505 EP 511 DI 10.2514/3.21650 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA UJ916 UT WOS:A1996UJ91600001 ER PT J AU Ohlmeyer, EJ AF Ohlmeyer, EJ TI Root-mean-square miss distance of proportional navigation missile against sinusoidal target SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article AB The performance of a proportional navigation homing missile against a target performing a sinusoidal weave maneuver is evaluated. The missile's effectiveness is measured in terms of the root-mean-square miss distance over a set of engagements in which the initial phase of the target weave is uniformly distributed. Closed form solutions for the root-mean-square miss are derived for the case where the missile guidance system is modeled by a first order lag and the lateral acceleration is unlimited. The analysis is then extended to include the effects of acceleration saturation and higher order missile dynamics. Comparisons are made between a first-order and a fifth-order guidance system, and the root-mean-square miss is determined numerically as a function of the interceptor's effective navigation gain, time constant and acceleration limit, and the target's weave amplitude and frequency. RP Ohlmeyer, EJ (reprint author), USN,CTR SURFACE WARFARE,MISSILE SYST DIV,DAHLGREN,VA 22448, USA. NR 14 TC 21 Z9 40 U1 0 U2 4 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAY-JUN PY 1996 VL 19 IS 3 BP 563 EP 568 DI 10.2514/3.21658 PG 6 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA UJ916 UT WOS:A1996UJ91600009 ER PT J AU Niewoehner, RJ Kaminer, II AF Niewoehner, RJ Kaminer, II TI Design of an autoland controller for an F-14 aircraft using H-infinity synthesis SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID SYSTEMS AB Our purpose is to present the results of a design effort to incorporate direct lift control into the F-14 aircraft automatic carrier landing system. This was accomplished using a new design methodology whereby typical single input/single output design specifications were translated into the weighting functions of an H-infinity output-feedback synthesis problem. Next, robustness of the H-infinity controller was analyzed using the structured singular value concept (mu). A simplified uncertainty model for air vehicles based on flight test data was developed for this analysis, Finally, the resulting controller was successfully validated on the nonlinear simulation. RP Niewoehner, RJ (reprint author), USN,POSTGRAD SCH,DEPT AERONAUT & ASTRONAUT,MONTEREY,CA 93943, USA. NR 18 TC 12 Z9 17 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAY-JUN PY 1996 VL 19 IS 3 BP 656 EP 663 DI 10.2514/3.21671 PG 8 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA UJ916 UT WOS:A1996UJ91600022 ER PT J AU Burl, JB Krueger, DL AF Burl, JB Krueger, DL TI Parametric uncertainty reduction in robust missile autopilot design SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article C1 USN,STRATEG WEAPONS FACIL,SILVERDALE,WA 98315. RP Burl, JB (reprint author), MICHIGAN TECHNOL UNIV,DEPT ELECT ENGN,1400 TOWNSEND DR,HOUGHTON,MI 49931, USA. NR 9 TC 2 Z9 2 U1 1 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAY-JUN PY 1996 VL 19 IS 3 BP 733 EP 736 DI 10.2514/3.21690 PG 4 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA UJ916 UT WOS:A1996UJ91600041 ER PT J AU Hollins, RA Merwin, LH Nissan, RA Wilson, WS Gilardi, R AF Hollins, RA Merwin, LH Nissan, RA Wilson, WS Gilardi, R TI Aminonitropyridines and their N-oxides SO JOURNAL OF HETEROCYCLIC CHEMISTRY LA English DT Article ID NUCLEOPHILIC-SUBSTITUTION; AMINATION AB 2,6-Diamino-3,5-dinitropyridine 1-oxide has been prepared by mixed acid nitration of 2,6-diaminopyridine, followed by oxidation using hydrogen peroxide in acetic acid. 3,5-Dinitro-2,4,6-triaminopyridine has been prepared by oxidative amination of 2-chloro-3,5-dinitropyridine or 2,6-diamino-3,5-dinitropyridine using potassium permanganate in liquid ammonia, or by ''vicarious nucleophilic amination'' of 2,6-diamino-3,5-dinitropyridine using hydroxylamine in aqueous potassium hydroxide. 3,5-Dinitro-2,4,6-triaminopyridine 1-oxide has been prepared by oxidation of 3,5-dinitro-2,4,6-triaminopyridine using hydrogen peroxide in acetic acid, and by ''vicarious nucleophilic amination'' of 2,6-diamino-3,5-dinitropyridine 1-oxide. Nmr spectroscopy and single crystal X-ray diffraction studies have shown that these compounds have the planar structures and intra- and inter-molecular hydrogen bonding necessary to confer on the materials the high density, the thermal and chemical stability, and the explosive insensitivity required for new insensitive energetic materials. C1 USN,RES LAB,STRUCT MATTER LAB,WASHINGTON,DC 20375. RP Hollins, RA (reprint author), USN,AIR WARFARE CTR,WEAPONS DIV,RES & TECHNOL DIV,CHINA LAKE,CA 93555, USA. NR 21 TC 48 Z9 58 U1 1 U2 6 PU HETERO CORPORATION PI TAMPA PA BOX 20285, TAMPA, FL 33622-0285 SN 0022-152X J9 J HETEROCYCLIC CHEM JI J. Heterocycl. Chem. PD MAY-JUN PY 1996 VL 33 IS 3 BP 895 EP 904 PG 10 WC Chemistry, Organic SC Chemistry GA VC216 UT WOS:A1996VC21600058 ER PT J AU Sanghera, JS Nguyen, VQ Pureza, PC Miklos, RE Kung, FH Aggarwal, ID AF Sanghera, JS Nguyen, VQ Pureza, PC Miklos, RE Kung, FH Aggarwal, ID TI Fabrication of long lengths of low-loss IR transmitting As40S(60-x)Se-x glass fibers SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article AB Teflon clad and As40S60 glass clad As40S55Se5 fibers transmitting in the 1-6 mu m wavelength region have been fabricated in lengths of about 50 m and with minimum losses of 0.098 and 0.65 dB/m, respectively. Short lengths of the Teflon clad fiber possessed a minimum loss of 0.047 dB/m. While current fiber losses are dominated by extrinsic scattering and absorption, the calculated theoretical minimum loss is estimated to be 3.6 dB/km at 5.3 mu m and is limited by the contribution from the weak absorption tail. Improvements in the purification and processing of the glasses into the optical fibers are required to reduce the losses further. C1 VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. SFA INC,LANDOVER,MD 20785. UNIV MARYLAND,RES FDN,GREENBELT,MD 20770. RP Sanghera, JS (reprint author), USN,RES LAB,CODE 56032,WASHINGTON,DC 20375, USA. NR 21 TC 47 Z9 49 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD MAY PY 1996 VL 14 IS 5 BP 743 EP 748 DI 10.1109/50.495154 PG 6 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA UL699 UT WOS:A1996UL69900015 ER PT J AU Saenz, AW AF Saenz, AW TI Long-time approximation to the evolution of resonant and nonresonant anharmonic oscillators in quantum mechanics SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article AB A simple normal-form approach is used to obtain uniform long-time approximations to the evolution of a resonant or nonresonant anharmonic oscillator system governed by a Hamiltonian H-epsilon which is a self-adjoint operator acting in the Hilbert space H = L(2)(R(nu)) (nu greater than or equal to 2) and is given formally by H-0 + epsilon V. Here H-0 denotes the Hamiltonian of nu one-dimensional harmonic oscillators whose coupling is represented by epsilon V, where nu is an operator of multiplication by a smooth function of at most polynomial growth at infinity and epsilon greater than or equal to 0 is a Small parameter. We consider the general situation in which rho greater than or equal to 1 of the frequencies of these oscillators are rationally independent, imposing a standard diophantine condition on the independent frequencies if rho greater than or equal to 2. Under these assumptions, which are stated in a mathematically precise way in the paper, an Nth-order approximant psi(N)(t,epsilon) to the exact solution psi(t,epsilon) of the Schrodinger equation id psi(t,epsilon)/dt = H-epsilon(t,epsilon) satisfying the initial condition psi(0,epsilon) = psi(0) is constructed inductively, psi(0) being an arbitrary E-independent member of a suitable family of smooth functions dense in H Our main result is that psi(N)(t,epsilon) differs from psi(t,epsilon) in H-norm by less than or equal to const epsilon(N + 1)(\t\ + 1) for all t is an element of R and all epsilon in an arbitrary compact interval [0,epsilon(0)]. (C) 1996 American Institute of Physics. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Saenz, AW (reprint author), CATHOLIC UNIV AMER,DEPT PHYS,WASHINGTON,DC 20064, USA. NR 31 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD MAY PY 1996 VL 37 IS 5 BP 2182 EP 2205 PG 24 WC Physics, Mathematical SC Physics GA UH888 UT WOS:A1996UH88800007 ER PT J AU Mejia, EA Hennrikus, WL Schwend, RM Emans, JB AF Mejia, EA Hennrikus, WL Schwend, RM Emans, JB TI A prospective evaluation of idiopathic left thoracic scoliosis with magnetic resonance imaging SO JOURNAL OF PEDIATRIC ORTHOPAEDICS LA English DT Article DE magnetic resonance imaging; scoliosis; syrinx ID SURGICAL-TREATMENT; SPINAL-CORD; SYRINGOMYELIA; CHILDREN; ABNORMALITIES; ADOLESCENTS; CHILDHOOD; SURGERY AB Twenty-nine consecutive patients with idiopathic left thoracic scoliosis were prospectively studied using magnetic resonance imaging (MRI). T1-weighted sagittal and axial images were obtained on all patients from the brainstem to the tip of the conus. Two patients (7%) had a syrinx on MRI. The remaining 27 patients had normal MRIs. The prevalence of brainstem and spinal cord anomalies was much less common than reported in previous retrospective reviews. C1 USN HOSP,SAN DIEGO,CA 92134. NR 39 TC 39 Z9 41 U1 0 U2 2 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0271-6798 J9 J PEDIATR ORTHOPED JI J. Pediatr. Orthop. PD MAY-JUN PY 1996 VL 16 IS 3 BP 354 EP 358 PG 5 WC Orthopedics; Pediatrics SC Orthopedics; Pediatrics GA UF696 UT WOS:A1996UF69600012 PM 8728637 ER PT J AU Viudez, A Tintore, J Haney, RL AF Viudez, A Tintore, J Haney, RL TI Circulation in the Alboran Sea as determined by quasi-synoptic hydrographic observations .1. Three-dimensional structure of the two anticyclonic gyres SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID VERTICAL MOTION; DIVERGENCE; VORTICITY; EQUATIONS; MEANDERS; FRONT AB The circulation and dynamics of the Modified Atlantic Water have been studied using data from an intensive field experiment carried out between 22 September and 7 October 1992. Data included 134 CTD casts, ADCP, and satellite imagery. A well-defined wavelike front was observed with two significant anticyclonic gyres in the western and eastern Alboran Sea. Smaller-scale cyclonic eddies were also observed. The front separates the more saline, older modified Atlantic water (S > 38) in the northern region from the fresher, more recent modified Atlantic water (S < 36.8) in the south. The associated baroclinic jet had a mean transport of 1 Sv and maximum geostrophic velocities of 1.0 m s(-1). The three-dimensional structure and spatial scales of both gyres were similar, that is, 90 km long and 220 m deep. In the eastern Alboran, northeast of Oran, the origin of the Algerian Current was also detected with an eastward transport of 1.8 Sv. The general picture can be presented as a structure formed by a wavelike front coupled with two large anticyclonic gyre-small cyclonic eddy systems. The relative importance of stratification, relative vorticity, and Froude number in the distribution of Ertel's potential vorticity has been examined, and potential vorticity conservation is used to infer vertical motion. The vertical velocity forcing has been computed using the quasigeostrophic Q vector formulation of the omega equation. It is found that the differential vorticity advection due to mesoscale phenomena in the western Alboran plays a main role in this forcing. The vertical velocities associated with these mesoscale structures reach maximum absolute values of 15 m day(-1). C1 UNIV ILLES BALEARS,DEPT FIS,E-07071 PALMA DE MALLORCA,SPAIN. RP Viudez, A (reprint author), USN,POSTGRAD SCH,DEPT METEOROL,ROOM 253,589 DYER RD,MONTEREY,CA 93943, USA. RI Viudez, Alvaro/A-8201-2008 OI Viudez, Alvaro/0000-0001-7862-9835 NR 38 TC 80 Z9 81 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD MAY PY 1996 VL 26 IS 5 BP 684 EP 705 DI 10.1175/1520-0485(1996)026<0684:CITASA>2.0.CO;2 PG 22 WC Oceanography SC Oceanography GA UL085 UT WOS:A1996UL08500003 ER PT J AU Viudez, A Haney, RL Tintore, J AF Viudez, A Haney, RL Tintore, J TI Circulation in the Alboran Sea as determined by quasi-synoptic hydrographic observations .2. Mesoscale ageostrophic motion diagnosed through density dynamical assimilation SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID COASTAL TRANSITION ZONE; GULF-STREAM; VERTICAL MOTION; SEASONAL THERMOCLINE; HIRLAM MODEL; OCEAN; INITIALIZATION; EVOLUTION; VORTICITY; FILAMENT AB The 3D velocity field in the Alboran Sea (Western Mediterranean) is diagnosed through density dynamical assimilation in a primitive equation (PE) model with mesoscale resolution. The ageostrophic motion is computed from fields produced by short-term backward and forward integrations of the PE model initialized with quasi-synoptic CTD data. A weight function based on a low-pass digital filter (Digital Filter Initialization method) is applied to the resulting rime series of model variables to obtain the final, dynamically balanced, density and 3D velocity fields. The diagnosed ageostrophic motion is interpreted by comparing the vertical velocity field with that obtained from the quasigeostrophic (QG) omega equation. The two methods produce very similar results with maximum vertical motions in the range of 10-20 m d(-1) associated with thr differential advection of relative vorticity in small-scale jet meanders [upward (downward) motion upstream (downstream) of the ridges]. Small local differences between PE and QG vertical velocities (typically 1-2 m d(-1))are attributed to known limitations of the QG theory and to differences between the analyzed and the dynamically initialized density fields. The horizontal ageostrophic motion in the western Alboran gyre (WAG) is in the same direction as the geostrophic motion above 100 m but in the opposite direction below 100 m. While the horizontal ageostrophic motion in the WAG can imply inflow or outflow depending on the position of local meanders, the gyre scale ageostrophic circulation is characterized by convergence above 100 m and divergence below 100 m, implying an average downward motion of less than 1 m d(-1). The general success of this assimilation approach could provide an alternative to QG diagnosis in mesoscale dynamics. C1 UNIV ILLES BALEARS,DEPT FIS,E-07071 PALMA DE MALLORCA,SPAIN. RP Viudez, A (reprint author), USN,POSTGRAD SCH,DEPT METEOROL,589 DYER RD,ROOM 253,MONTEREY,CA 93943, USA. RI Viudez, Alvaro/A-8201-2008 OI Viudez, Alvaro/0000-0001-7862-9835 NR 51 TC 31 Z9 31 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD MAY PY 1996 VL 26 IS 5 BP 706 EP 724 DI 10.1175/1520-0485(1996)026<0706:CITASA>2.0.CO;2 PG 19 WC Oceanography SC Oceanography GA UL085 UT WOS:A1996UL08500004 ER PT J AU Terray, EA Donelan, MA Agrawal, YC Drennan, WM Kahma, KK Williams, AJ Hwang, PA Kitaigorodskii, SA AF Terray, EA Donelan, MA Agrawal, YC Drennan, WM Kahma, KK Williams, AJ Hwang, PA Kitaigorodskii, SA TI Estimates of kinetic energy dissipation under breaking waves SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID WIND-GENERATED WAVES; SURFACE MIXED LAYER; TURBULENCE MEASUREMENTS; VELOCITY-FIELD; OCEAN; SPECTRA; GROWTH; WATER AB The dissipation of kinetic energy at the surface of natural water bodies has important consequences for many physical and biochemical processes including wave dynamics, gas transfer, mixing of nutrients and pollutants, and photosynthetic efficiency of plankton. Measurements of dissipation close to the surface obtained in a large lake under conditions of strong wind forcing are presented that show a layer of enhanced dissipation exceeding wall layer values by one or two orders of magnitude. The authors propose a scaling for the rate of dissipation based on wind and wave parameters, and conclude that the dissipation rate under breaking waves depends on depth, to varying degrees, in three stages. Very near the surface, within one significant height, the dissipation rate is high (an order of magnitude greater than that predicted by wall layer theory) and roughly constant. Below this is an intermediate region where the dissipation decays as z(-2). The thickness of this layer (relative to the significant wave height) is proportional to the energy flux from breaking normalized by rho u*(3), which for young waves is proportional to wave age. At sufficient depth the dissipation rate asymptotes to values commensurate with a traditional wall layer. The total energy flux into the water column can be an order of magnitude greater than the conventional estimate of rho u*(3)/2 and depends strongly on wave age. These results imply a pronounced shift in our approach to estimating kinetic energy dissipation in wave-stirred regions and in the modeling of various physical, chemical, and biological processes. C1 ENVIRONM CANADA,CANADA CTR INLAND WATERS,NATL WATER RES INST,BURLINGTON,ON L7R 4A6,CANADA. SEQUOIA SCI INC,MERCER ISL,WA. FINNISH INST MARINE RES,HELSINKI,FINLAND. NAVAL RES LAB,BAY ST LOUIS,MS. RP Terray, EA (reprint author), WOODS HOLE OCEANOG INST,DEPT APPL OCEAN PHYS & ENGN,217 BIDELOW,WOODS HOLE,MA 02543, USA. RI Kahma, Kimmo/A-3407-2013 NR 51 TC 337 Z9 348 U1 1 U2 22 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD MAY PY 1996 VL 26 IS 5 BP 792 EP 807 DI 10.1175/1520-0485(1996)026<0792:EOKEDU>2.0.CO;2 PG 16 WC Oceanography SC Oceanography GA UL085 UT WOS:A1996UL08500009 ER PT J AU Moore, FG McInville, RM Hymer, T AF Moore, FG McInville, RM Hymer, T TI Aeroprediction code for angles of attack above 30 degrees SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB The U.S. Naval Surface Warfare Center Dahlgren Division aeroprediction code has been extended to angles of attack greater than 30 deg. To accomplish this, several databases were used to approximate the nonlinearities in individual missile component aerodynamics. Theoretical aerodynamic methods were used at small angles of attack. The new semiempirical model was then applied to several configurations and the empirical constants fine tuned so as to minimize some of the errors associated with wind-tunnel measurements of component aerodynamics af high angles of attack. New and improved technology developed includes 1) extension of the wing-body and body-wing interference factor methodology above angle of attack of 30 deg for both zero and nonzero control deflections and 2) refinements In body-alone normal force and center-of-pressure prediction to account for Reynolds number, and transonic and asymmetrically shed body vortices. All methodology is developed for the Phi = 0-deg (or fins in pins) roll orientation, Comparison of the new methodology to several cases outside the databases on which the methodology was developed appears to indicate the average accuracy goals of +/-10% on normal force and +/-4% of body length on center of pressure were maintained for the higher angles of attack. RP Moore, FG (reprint author), USN,CTR SURFACE WARFARE,DEPT WEAPONS SYST,DAHLGREN DIV,AEROMECH BRANCH,DAHLGREN,VA 22448, USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD MAY-JUN PY 1996 VL 33 IS 3 BP 366 EP 373 DI 10.2514/3.26769 PG 8 WC Engineering, Aerospace SC Engineering GA UQ303 UT WOS:A1996UQ30300009 ER PT J AU Feit, D Cuschieri, JM AF Feit, D Cuschieri, JM TI Scattering of sound by a fluid-loaded plate with a distributed mass inhomogeneity SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID VIBRATION AB The scattering of a plane acoustic wave by a fluid-loaded, thin, elastic plate, of infinite extent, with a distributed mass inhomogeneity is investigated. Two approaches are presented, an iterative approach valid when a measure of the distributed impedance is much lower than that of the uniform fluid-loaded plate, acid a full numerical solution which while having no restricting assumptions is somewhat demanding computationally. For the iterative solution a set of correction terms is evaluated and applied to the response of the uniform plate with no inhomogeneities. The number of correction terms required is dependent on the relative magnitude of the inhomogeneity, In the full numerical solution, the presence of the distributed inhomogeneity in the equation of motion, when expressed in the wave-number domain, results in a Fredholm integral equation of the third kind. By substituting for the product of the response and the plate characteristic equation (impedance), the Fredholm integral of the third kind is reduced to a Fredholm integral of the second kind. The plate response in the spectral wave-number domain is obtained from the solution of the Fredholm integral. Inverse Fourier transforming the wave-number domain response function gives the spatial domain solution for the response. The hybrid numerical analytical approach [J. Acoust. Soc. Am. 95, 1998-2005 (1994)] is used to perform the inverse Fourier transform, The far-field scattered pressure is obtained from the spectral domain solution of the response. Response and scattered pressure results for distributed mass inhomogeneities, with different distribution functions, are presented and compared to the results for a line inhomogeneity. (C) 1996 Acoustical Society of America. C1 FLORIDA ATLANTIC UNIV,DEPT OCEAN ENGN,CTR ACOUST & VIBRAT,BOCA RATON,FL 33431. RP Feit, D (reprint author), DAVID TAYLOR RES CTR,NSWC,CARDEROCK DIV,BETHESDA,MD 20084, USA. NR 12 TC 13 Z9 13 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAY PY 1996 VL 99 IS 5 BP 2686 EP 2700 DI 10.1121/1.414811 PG 15 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UK253 UT WOS:A1996UK25300007 ER PT J AU Huang, H Gaunaurd, GC AF Huang, H Gaunaurd, GC TI Acoustic point source scattering by a spherical elastic shell submerged beneath a free surface SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB The scattering of incident acoustic plane waves by a submerged spherical elastic shell near a free surface has previously been analyzed in detail using an exact, classical separation of variables solution. The problem is studied here again for cases where the incident waves are emitted from point sources at arbitrary positions in space. The result demonstrates that for a nearby point source, the scattered wave field is signifcantly different from that due to a plane incident wave, and that when the distance from the point source to the shell is more than 20 shell radii, the backscattered echo can be closely approximated by that of a plane incident wave. The scattered field due to an array of point sources can also be obtained by linear superpositions of the solution developed here. C1 USN,CTR SURFACE WARFARE,CARDEROCK DIV,SILVER SPRING,MD 20903. RP Huang, H (reprint author), USN,CTR SURFACE WARFARE,INDIAN HEAD DIV,SILVER SPRING,MD 20903, USA. NR 15 TC 9 Z9 10 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAY PY 1996 VL 99 IS 5 BP 2720 EP 2726 DI 10.1121/1.414814 PG 7 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UK253 UT WOS:A1996UK25300010 ER PT J AU Maidanik, G Dickey, J AF Maidanik, G Dickey, J TI Loss factors of pipelike structures containing beads SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB It is found that when beads are inserted into the interior of a pipelike structure, the damping of this beaded structure may substantially exceed that of the unbeaded structure. The beads are modeled by a ''beaded fluid'' characterized by a low density, a low sound speed, and a high loss factor, Statistical energy analysis (SEA) is developed to account for the presence of the beaded fluid within the structure. It is shown that in certain frequency regimes and certain choices of the parameters that characterize the beaded fluid, relative to those that characterize the structure, the loss factor of the beaded structure can be designed to significantly exceed that of the unbeaded structure. The mechanism for the increase lies in that the stored energy in the beaded fluid may, in the ''steady state,'' be made to substantially exceed that in the structure. The bulk of the stored energy is then decimated by the high damping capability that the beaded fluid enjoys. A selected number of computer experiments are cited to illustrate the potential effectiveness of this damping mechanism and the manner by which the parameters that define the beads and the structure, control it. RP Maidanik, G (reprint author), NSWC,DAVID TAYLOR MODEL BASIN,BETHESDA,MD 20084, USA. NR 6 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAY PY 1996 VL 99 IS 5 BP 2766 EP 2774 DI 10.1121/1.415212 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UK253 UT WOS:A1996UK25300015 ER PT J AU Creamer, DB AF Creamer, DB TI Scintillating shallow-water waveguides SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID NORMAL MODE AMPLITUDES; RANDOM-MEDIA; RANDOM OCEAN; STATISTICS; CHANNEL; MOMENT; TIME AB An analysis of acoustic wave propagation in a random shallow-water waveguide with an energy absorbing sub-bottom is presented, in which deviations of the index of refraction are a stochastic process. The specific model studied is motivated by the oceanic waveguide in shallow waters, in which the sub-bottom sediment leads to energy loss from the acoustic field, and the stochastic process results from internal (i.e., density) waves. In terms of the normal modes of the waveguide, the randomness leads to mode coupling while the energy loss results from different attenuation rates for the various modes (i.e., mode stripping). The distinction in shallow water is that there exists a competition between the mode-coupling terms, which redistribute the modal energies, and mode stripping, which results in an irreversible loss of energy. Theoretically, averaged equations are formulated for both the modal intensities and fluctuations (the second and fourth moments of acoustic pressure, respectively), similar to previous formulations which, however, did not include the effects of sub-bottom absorption of acoustic energy. The theory developed here predicts that there is a mismatch between decay rates between the second and fourth moments, implying that the scintillation index (which is a measure of the strength of the random scattering) grows exponentially in range. Thus the usual concept of equilibrium or saturated statistics must be modified. This theoretical prediction is generally valid and depends only on assuming the forward scattering approximation, the Markov approximation (i.e., the short-range nature of the correlations between sound-speed fluctuations) and neglecting the cross-modal coherences. In order to assess the importance of these assumptions Monte Carlo simulations of stochastic coupled-mode equations are presented. For these simulations, models of internal-wave processes, deterministic shallow-water acoustic environments, and sub-bottom attenuation that simplify the numerical computation were chosen. While these models are unrealistic they illustrate the theoretically predicted behavior. RP Creamer, DB (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 21 TC 50 Z9 51 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAY PY 1996 VL 99 IS 5 BP 2825 EP 2838 DI 10.1121/1.414817 PG 14 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UK253 UT WOS:A1996UK25300021 ER PT J AU Makris, NC AF Makris, NC TI Parameter resolution bounds that depend on sample size SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB It is currently common practice in theoretical ocean acoustics to derive parameter resolution bounds for a monochromatic measurement of the temporally fluctuating field received by a hydrophone array. However, a monochromatic measurement corresponds to a single random sample. In applied ocean acoustics, single samples are seldom if ever used for parameter estimation because the associated error can be unnecessarily large. Instead estimates are derived from ensemble averages such as the sample covariance. To bridge the gap between these two approaches, the Fisher Information for the sample covariance is shown to be equal to the number of independent and stationary samples times the Fisher Information for a single sample. Therefore, there are no practical limits on parameter resolution if (1) the bound for a single sample is finite, which is generally the case of interest, (2) a sufficiently large population of independent samples can be found. The parameter resolution issue then becomes one of determining the maximum number of such samples. This number is set by physical variables that do not appear in the monochromatic or instantaneous measurement. A means of determining this number from the temporal coherence of the received field and the measurement time is presented. RP Makris, NC (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 33 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAY PY 1996 VL 99 IS 5 BP 2851 EP 2861 DI 10.1121/1.414879 PG 11 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UK253 UT WOS:A1996UK25300023 ER PT J AU Mittleman, J Thompson, RB Han, YK AF Mittleman, J Thompson, RB Han, YK TI Elastic wave scattering by shelled spherical scatterers in a focused field SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID INTERFACE LAYERS; INCLUSIONS; RADIATION; SOLIDS AB Embrittlement of many important metal alloys has been related to the accumulation of undesirable materials at grain boundaries, a condition which may be detectable through measurement of ultrasonic scattering from the material's microstructure, Grains with decorated grain boundaries are modeled as shelled microspheres embedded in an isotropic elastic host, and a practical means of predicting scattering from these particles is developed. The incident field often used for measuring backscattered grain noise is focused; both plane and focused incident fields are treated, Theoretical predictions of scattering from isolated scatterers are compared with experimental measurements on metal microspheres embedded in plastic to validate the computational procedure, then predictions of scattering from similar spherical structures embedded in a metal host are presented. In the former case theoretical predictions are found consistent with observations, although differences between shelled and nonshelled scatterers are obscured by the great contrast between host and scatterer. In the latter case, where host and core are quite similar, even thin shells can produce scattering readily distinguishable from the weak scattering in polycrystals that may be due to locally inhomogeneous properties. Results of this study can be used to calculate a backscattering coefficient for calculations of grain noise in metals containing, or composed of, numerous shelled scatterers. (C) 1996 Acoustical Society of America. C1 IOWA STATE UNIV SCI & TECHNOL,CTR NONDESTRUCT EVALUAT,AMES,IA 50011. RP Mittleman, J (reprint author), USN,CTR SURFACE WARFARE,DAHLGREN DIV,COASTAL SYST STN,PANAMA CITY,FL 32407, USA. NR 39 TC 2 Z9 2 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAY PY 1996 VL 99 IS 5 BP 2862 EP 2870 DI 10.1121/1.414788 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UK253 UT WOS:A1996UK25300024 ER PT J AU Sanghera, JS Nguyen, VQ Aggarwal, ID AF Sanghera, JS Nguyen, VQ Aggarwal, ID TI Properties of As40S((60-x))Se-x glasses for IR fiber optics SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB The physical and optical properties of glasses in the As40S(60-x)Se-x system where x = 0, 5, 10, 15, and 20 at.% Se have been investigated, The changes in the glass transition temperature, density, hardness, IR edge, and refractive index can be attributed to the presence of Se, which simply replaces S in these glasses, The glasses do not exhibit crystallization under the conditions used in this study, which is a desirable property from the viewpoint of fiberization, Appropriate core and cladding glass compositions have been identified for fabrication of optical fibers with known numerical apertures, Furthermore, it has been shown that these glasses mill not impart additional thermal or mechanical stresses in optical fibers made from these compositions. C1 VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. RP Sanghera, JS (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 19 TC 16 Z9 16 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAY PY 1996 VL 79 IS 5 BP 1324 EP 1328 DI 10.1111/j.1151-2916.1996.tb08592.x PG 5 WC Materials Science, Ceramics SC Materials Science GA UM323 UT WOS:A1996UM32300028 ER PT J AU Bashkansky, M Battle, PR Duncan, MD Kahn, M Reintjes, J AF Bashkansky, M Battle, PR Duncan, MD Kahn, M Reintjes, J TI Subsurface defect detection in ceramics using an optical gated scatter reflectometer SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID COHERENCE-DOMAIN REFLECTOMETRY AB We demonstrate the use of optical gating techniques for determining the size and location of defects in advanced ceramic materials, The subsurface region in various silicon nitride ceramic materials is probed. using an optical gated reflectometer based on a low-coherence fiber interferometer. Experimental results indicate that the size and distribution of small subsurface defects can be determined with depth and lateral resolutions of 10 and 7 mu m, respectively. RP Bashkansky, M (reprint author), USN,RES LAB,LASER PHYS BRANCH,CODE 5640,WASHINGTON,DC 20375, USA. NR 11 TC 12 Z9 12 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAY PY 1996 VL 79 IS 5 BP 1397 EP 1400 DI 10.1111/j.1151-2916.1996.tb08602.x PG 4 WC Materials Science, Ceramics SC Materials Science GA UM323 UT WOS:A1996UM32300038 ER PT J AU OGrady, WE Pandya, KI Swider, KE Corrigan, DA AF OGrady, WE Pandya, KI Swider, KE Corrigan, DA TI In situ x-ray absorption near-edge structure evidence for quadrivalent nickel in nickel battery electrodes SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID OXIDE ELECTRODE; HYDROXIDES AB The oxidation state of nickel in a nickel oxide battery has been examined using x-ray absorption spectroscopy. Chemically synthesized beta-NiOOH and BaNiO3 were used as reference standards for the Ni(III) and Ni(IV) oxidation states of nickel, respectively. The shift of the Ni K-edge absorption in both a completely charged nickel oxide electrode (NOE) and a 1000% overcharged nickel oxide electrode corresponds to a Ni oxidation state of +3.5. This oxidation state clearly indicates the presence of Ni+4 in the charged electrodes. C1 N CAROLINA STATE UNIV,DEPT PHYS,RALEIGH,NC 27695. OVON BATTERY CO,TROY,MI 48084. RP OGrady, WE (reprint author), USN,RES LAB,SURFACE CHEM BRANCH,WASHINGTON,DC 20375, USA. NR 24 TC 81 Z9 82 U1 4 U2 21 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD MAY PY 1996 VL 143 IS 5 BP 1613 EP 1616 DI 10.1149/1.1836687 PG 4 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA UK930 UT WOS:A1996UK93000029 ER PT J AU Russell, JN Bermudez, VM Leming, A AF Russell, JN Bermudez, VM Leming, A TI Low temperature growth of AlN(0001) on Al(111) using hydrazoic acid (HN3) SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A LA English DT Article; Proceedings Paper CT 42nd National Symposium of the American-Vacuum-Society CY OCT 16-20, 1995 CL MINNEAPOLIS, MN SP Amer Vacuum Soc ID ALUMINUM NITRIDE; AL-NITRIDE; ELECTRON-SPECTROSCOPY; ION-IMPLANTATION; CARBON-DIOXIDE; FILMS; GAN; SURFACES; ADSORPTION; ACTIVATION AB Thin films of AlN(0001) were grown by reacting hydrazoic acid (HN3) with an Al(111) substrate at temperatures below 800 K. The resulting films were characterized with Auger electron spectroscopy, low energy electron diffraction (LEED), and infrared reflection-absorption spectroscopy (IRRAS). The energies and line shapes of the Al LVV and N KLL Auger transitions were consistent with those of AIN. A hexagonal LEED pattern, in registry with that of the Al(111) substrate, was observed for the fully nitrided film and was consistent with a single-domain, AlN(0001) surface. Only the A(1) LO phonon mode of AIN, at 886 cm(-1), was observed in IRRAS, indicating a wurtzite-structured film with the c axis normal to the surface plane. C1 USN, RES LAB, ELECTR SCI & TECHNOL DIV, WASHINGTON, DC 20375 USA. RP Russell, JN (reprint author), USN, RES LAB, DIV CHEM, WASHINGTON, DC 20375 USA. RI Russell, John/A-3621-2009 NR 47 TC 14 Z9 14 U1 0 U2 1 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0734-2101 EI 1520-8559 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A PD MAY-JUN PY 1996 VL 14 IS 3 BP 908 EP 912 DI 10.1116/1.580413 PN 1 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA UR134 UT WOS:A1996UR13400046 ER PT J AU Thibado, PM Bennett, BR Twigg, ME Shanabrook, BV Whitman, LJ AF Thibado, PM Bennett, BR Twigg, ME Shanabrook, BV Whitman, LJ TI Evolution of GaSb epitaxy on GaAs(001)-c(4x4) SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 42nd National Symposium of the American-Vacuum-Society CY OCT 16-20, 1995 CL MINNEAPOLIS, MN SP Amer Vacuum Soc ID GROWTH AB The growth of GaSb films by molecular beam epitaxy on GaAs(001)-c(4x4) at 490 degrees C has been studied in situ with scanning tunneling microscopy and ex situ with transmission electron microscopy. As the film is deposited, four distinct growth regimes are observed: the first two monolayers grow layer by layer with platelet-like two-dimensional (2D) islands; the next monolayer forms coherently strained three-dimensional (3D) quantum dots; further deposition induces film relaxation and rough 3D growth; for film thicknesses >100 nm the growth is again 2D, proceeding via spiral growth around emerging threading dislocations. The atomic-scale mechanisms inherent in the transitions between the growth regimes are discussed. Variations in growth procedures aimed at improving the quantum dot uniformity and reducing the dislocation density are proposed. (C) 1996 American Vacuum Society. RP Thibado, PM (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Bennett, Brian/A-8850-2008; Whitman, Lloyd/G-9320-2011 OI Bennett, Brian/0000-0002-2437-4213; Whitman, Lloyd/0000-0002-3117-1174 NR 18 TC 38 Z9 38 U1 0 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAY-JUN PY 1996 VL 14 IS 3 BP 885 EP 889 DI 10.1116/1.580408 PN 1 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA UR134 UT WOS:A1996UR13400041 ER PT J AU Whitman, LJ Thibado, PM Linker, F Patrin, J AF Whitman, LJ Thibado, PM Linker, F Patrin, J TI Versatile sample handling system for scanning tunneling microscopy studies of molecular beam epitaxy SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article C1 PACIFIC SCI INSTRUMENTS,SUNNYVALE,CA 94089. RP Whitman, LJ (reprint author), USN,RES LAB,CODE 6177,WASHINGTON,DC 20375, USA. RI Whitman, Lloyd/G-9320-2011 OI Whitman, Lloyd/0000-0002-3117-1174 NR 5 TC 16 Z9 16 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1996 VL 14 IS 3 BP 1870 EP 1872 DI 10.1116/1.588570 PG 3 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA UU480 UT WOS:A1996UU48000048 ER PT J AU Ancona, MG AF Ancona, MG TI Modeling of thermal effects in silicon field emitters SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 8th International Vacuum Microelectronics Conference (IVMC 95) CY JUL 31-AUG 03, 1995 CL PORTLAND, OR SP IEEE, ARPA, NRL, Japan Soc Promot Sci, AVS ID EMISSION; ELECTRON; TIPS AB Thermal effects in silicon field emitters are analyzed and an attempt is made to identify ''intrinsic'' phenomena that can occur under normal operating conditions which might trigger catastrophic breakdown. For this analysis, an approximate quasiequilibrium treatment is employed that is presumably most accurate at low current levels. Unlike for metal field emitters, where Nottingham heating dominates, for silicon field emitters it is found that the heating is predominantly ohmic in origin except at low currents. The temperatures produced by this heating are much larger than those in metals for a given current and geometry. And although the calculations indicate that for typical designs these temperatures are still small enough so as not to represent a direct reliability threat, their size coupled with their sensitivity to changes in current (ohmic heating increases as the square of the current) suggests caution both in design and in trusting the results of this relatively crude analysis. With respect to the former, designs for which the heat sinking is weak, e.g., atomically sharp tips or tips on high aspect-ratio posts, may be susceptible to thermal failure. Similarly, additional ohmic heating due to ac currents can push a design into thermal jeopardy. Finally, it is found that increasing the doping does not appear to lessen the ohmic heating significantly (because of band bending and scattering effects), nor does the Nottingham effect, which under some circumstances seems to actually provide cooling, appear sufficient to offset the ohmic effects. RP Ancona, MG (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 19 TC 14 Z9 14 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1996 VL 14 IS 3 BP 1918 EP 1923 DI 10.1116/1.588955 PG 6 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA UU480 UT WOS:A1996UU48000059 ER PT J AU Jensen, KL Zaidman, EG Kodis, MA Goplen, B Smithe, DN AF Jensen, KL Zaidman, EG Kodis, MA Goplen, B Smithe, DN TI Analytical and seminumerical models for gated field emitter arrays .1. Theory SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 8th International Vacuum Microelectronics Conference (IVMC 95) CY JUL 31-AUG 03, 1995 CL PORTLAND, OR SP IEEE, ARPA, NRL, Japan Soc Promot Sci, AVS ID EMISSION; SIMULATION; DISPLAYS AB A simple analytic approach for gated field emission array unit cell modeling, the ''Saturn'' model, has been developed and serves to show how those parameters which most affect inductive output amplifier performance are dependent on the material and geometry of the unit cell. The Saturn model replaces the field emission tip with a sphere and the gate with a charged ring. A relation then exists between the gate radius, the gate voltage, the sphere radius, the field, and its angular variation on the sphere, from which the total emitted current may be given analytically, and from which the geometric and material dependence of those quantities which most affect amplifier performance (Fowler Nordheim A and B parameters, tip field, capacitance, and field enhancement factor) can be qualitatively determined. The qualitative predictions of this model may be made quantitative (the ''seminumerical model'') by the inclusion of a subset of parameters normally provided in a full boundary element numerical simulation which accounts for how the field varies along the surface of the emitter. The manner in which a statistical distribution of tip radii affects the least-squares estimate of the A and B parameters is shown. C1 MISSION RES CORP,NEWINGTON,VA 22122. RP Jensen, KL (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Jensen, Kevin/I-1269-2015 OI Jensen, Kevin/0000-0001-8644-1680 NR 23 TC 29 Z9 29 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1996 VL 14 IS 3 BP 1942 EP 1946 DI 10.1116/1.588960 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA UU480 UT WOS:A1996UU48000064 ER PT J AU Jensen, KL Zaidman, EG Kodis, MA Goplen, B Smithe, DN AF Jensen, KL Zaidman, EG Kodis, MA Goplen, B Smithe, DN TI Analytical and seminumerical models for gated field emitter arrays .2. Comparison of theory to experiment SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 8th International Vacuum Microelectronics Conference (IVMC 95) CY JUL 31-AUG 03, 1995 CL PORTLAND, OR SP IEEE, ARPA, NRL, Japan Soc Promot Sci, AVS ID EMISSION; SIMULATION AB The utility of analytic and seminumerical models for a gated field emitter array (FEA) unit cell is judged by comparing the predictions of the Saturn and seminumerical models against the numerically simulated behavior for FEA parameters deemed most important from the standpoint of rf amplifier applications. The numerical simulation algorithm based on the Boundary Element method, used to validate the seminumerical model and to test the qualitative predictions of the Saturn model, is briefly described. Further, by varying the distribution of emitters, work function, and tip radius, we match experimental data given in the Literature for molybdenum FEAs: the manner in which the relevant geometrical and material parameters are chosen is explained and shown to be compatible with physically based expectations about emitter geometry and materials. C1 MISSION RES CORP,NEWINGTON,VA 22122. RP Jensen, KL (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Jensen, Kevin/I-1269-2015 OI Jensen, Kevin/0000-0001-8644-1680 NR 16 TC 8 Z9 8 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1996 VL 14 IS 3 BP 1947 EP 1951 DI 10.1116/1.588961 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA UU480 UT WOS:A1996UU48000065 ER PT J AU Kodis, MA Jensen, KL Zaidman, EG Goplen, B Smithe, DN AF Kodis, MA Jensen, KL Zaidman, EG Goplen, B Smithe, DN TI Optimization of field emission arrays for inductive output amplifiers SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 8th International Vacuum Microelectronics Conference (IVMC 95) CY JUL 31-AUG 03, 1995 CL PORTLAND, OR SP IEEE, ARPA, NRL, Japan Soc Promot Sci, AVS AB In an inductive output amplifier, an emission gated electron beam induces high-frequency fields in an output circuit via displacement currents, not convection current. Emission gated electron beams experience strong interactions when traversing a resonant or synchronous electromagnetic field, and this strong interaction is responsible for both the interesting nonlinear physics and the attractive efficiency and compactness of emission gated amplifiers. Field emission cathodes, due to their extremely low electron transit time and high transconductance, offer the opportunity to extend the advantages of emission gating into C and X bands. Design criteria for the joint optimization of the field emission arrays (FEAs) structure and the rf input and output circuits of inductive output amplifiers are presented. It is found that while output circuits yielding net efficiencies of 50% or greater are well within the state of the art, the gain is likely to be moderate (10-20 dB). With today's FEA performance, a desirable operating regime is achievable, yielding a new class of compact, highly efficient, and moderate gain power booster amplifiers. (C) 1996 American Vacuum Society. C1 MISSION RES CORP,NEWINGTON,VA 22102. RP Kodis, MA (reprint author), USN,RES LAB,CODE 6840,WASHINGTON,DC 20375, USA. RI Jensen, Kevin/I-1269-2015 OI Jensen, Kevin/0000-0001-8644-1680 NR 6 TC 7 Z9 7 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1996 VL 14 IS 3 BP 1990 EP 1993 DI 10.1116/1.588971 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA UU480 UT WOS:A1996UU48000075 ER PT J AU Zaidman, EG Jensen, KL Kodis, MA AF Zaidman, EG Jensen, KL Kodis, MA TI A, B, and C characterization of gated field emission arrays for radio frequency device performance SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 8th International Vacuum Microelectronics Conference (IVMC 95) CY JUL 31-AUG 03, 1995 CL PORTLAND, OR SP IEEE, ARPA, NRL, Japan Soc Promot Sci, AVS AB A method for predicting the Fowler-Nordheim parameters A and B, and the capacitance for a unit cell of a gated field emission array is developed, applied, and integrated into end-to-end rf amplifier design. Density modulated rf amplifiers require a high frequency, well characterized electron emission source for efficient operation; a cathode constructed of field emission arrays is a potential candidate for insertion into the next generation of twystode and klystrode amplifiers. The A, B, and C parameterization of the emission from model unit cell geometries is done by a boundary element technique. The behavior of A, B, and C with variation in device material and geometry is illustrated with two sample case sets. Finally, the utility of A, B, and C in predicting rf device performance requirements is illustrated. RP Zaidman, EG (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Jensen, Kevin/I-1269-2015 OI Jensen, Kevin/0000-0001-8644-1680 NR 11 TC 8 Z9 8 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1996 VL 14 IS 3 BP 1994 EP 1999 DI 10.1116/1.588972 PG 6 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA UU480 UT WOS:A1996UU48000076 ER PT J AU Shaw, L Gray, HF Jensen, KL Jung, TM AF Shaw, L Gray, HF Jensen, KL Jung, TM TI Graded electron affinity electron source SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 8th International Vacuum Microelectronics Conference (IVMC 95) CY JUL 31-AUG 03, 1995 CL PORTLAND, OR SP IEEE, ARPA, NRL, Japan Soc Promot Sci, AVS ID MOLECULAR-BEAM EPITAXY AB We describe a new electron source using electric field and low electron affinity semiconductor materials to bring charge to potential energy levels near the vacuum level while still in the solid. The basic idea involves moving some of the potential barrier from the surface to the bulk, and distributing the barrier over a thin layer below the surface. In so doing, the emission physics is changed fundamentally from a quantum mechanical tunneling process largely controlled by surface properties to a classical transport process largely controlled by the band structure of a wide bandgap semiconductor. The composition of the thin layer below the surface would be graded such that the conduction band minimum changes from an energy close to the substrate Fermi level to an energy significantly closer to the vacuum level. Electrons from the substrate would be drawn into the graded composition layer with an electric field produced by a pointed emitter structure and extraction gate similar to that used in field emitter arrays. Relative to a conventional field emitter array, the new source is expected to require lower extraction fields and exhibit improved emission uniformity, stability, and noise. The I-V characteristics are not Fowler-Nordheim and may include a saturation effect at high current densities that could be engineered to improve reliability and uniformity. The group III nitrides can be grown with a continuous range of composition that provides the range of electron affinity needed to produce the proposed electronic structure. (C) 1996 American Vacuum Society. RP USN, RES LAB, WASHINGTON, DC 20375 USA. RI Jensen, Kevin/I-1269-2015 OI Jensen, Kevin/0000-0001-8644-1680 NR 25 TC 44 Z9 44 U1 0 U2 2 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1996 VL 14 IS 3 BP 2072 EP 2079 DI 10.1116/1.588988 PG 8 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA UU480 UT WOS:A1996UU48000092 ER PT J AU Bennett, BR Thibado, PM Twigg, ME Glaser, ER Magno, R Shanabrook, BV Whitman, LJ AF Bennett, BR Thibado, PM Twigg, ME Glaser, ER Magno, R Shanabrook, BV Whitman, LJ TI Self-assembled InSb and GaSb quantum dots on GaAs(001) SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 15th North American Conference on Molecular Beam Epitaxy CY SEP 17-20, 1995 CL UNIV MARYLAND, COLLEGE PK, MD HO UNIV MARYLAND AB Quantum dots of InSb and GaSb were grown on GaAs(001) by molecular-beam epitaxy. In situ scanning tunneling microscopy measurements taken after 1-2 monolayers of InSb or GaSb growth reveal the surface is a network of anisotropic ribbon-like platelets. These platelets are a precursor to quantum dot growth. Transmission electron microscopy measurements indicate that the quantum dots are coherently strained. Quantum dots of InSb and GaSb capped by GaAs exhibit strong luminescence near 1.1 eV. RP Bennett, BR (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Bennett, Brian/A-8850-2008; Whitman, Lloyd/G-9320-2011 OI Bennett, Brian/0000-0002-2437-4213; Whitman, Lloyd/0000-0002-3117-1174 NR 17 TC 27 Z9 27 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1996 VL 14 IS 3 BP 2195 EP 2198 DI 10.1116/1.588898 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA UU480 UT WOS:A1996UU48000119 ER PT J AU Hobart, KD Kub, FJ Jemigan, GG Thompson, PE AF Hobart, KD Kub, FJ Jemigan, GG Thompson, PE TI Surface segregation of arsenic and phosphorus from buried layers during Si molecular beam epitaxy SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 15th North American Conference on Molecular Beam Epitaxy CY SEP 17-20, 1995 CL UNIV MARYLAND, COLLEGE PK, MD HO UNIV MARYLAND ID SI(100) AB Unintentional doping of silicon films grown on heavily doped buried layers of arsenic and phosphorus during silicon molecular beam epitaxy has been studied by spreading resistance profiling and x-ray photoelectron spectroscopy. The measurements indicate that dopant surface segregation during growth is responsible for the unintentional doping. The segregation phenomenon has been characterized over a growth temperature range of 450-750 degrees C. The growth on heavily doped buried layers has implications for device applications such as Si/SiGe heterojunction bipolar transistors. Epitaxial processes to circumvent this effect and create abrupt doping profiles are explored. RP Hobart, KD (reprint author), USN,RES LAB,DIV ELECTR SCI & TECHNOL,WASHINGTON,DC 20375, USA. NR 12 TC 11 Z9 11 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1996 VL 14 IS 3 BP 2229 EP 2232 DI 10.1116/1.588906 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA UU480 UT WOS:A1996UU48000127 ER PT J AU Andrews, MD VanHoosier, ME AF Andrews, MD VanHoosier, ME TI Calibration of the solar ultraviolet spectral irradiance monitor (SUSIM) on ATLAS-2 SO METROLOGIA LA English DT Article; Proceedings Paper CT 5th International Conference on Radiometry CY SEP 19-21, 1994 CL BERLIN, GERMANY SP Phys Tech Bundesanstalt AB Uncertainty in the calibration of the Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) produces an uncertainty in the measurement of solar irradiance. The three primary sources of uncertainty in the irradiance during the ATLAS-2 mission are from wavelength determination, irradiance standard, and the in-flight ageing correction. The wavelength determination leads to an uncertainty in the irradiance in both the calibration data and the solar observations. The first effect is important only at short wavelengths. The second effect is important wherever the solar spectrum is steep but can be eliminated by summing over spectral features. The uncertainty in the irradiance standard is about 2%. The ageing correction produces a wavelength-dependent uncertainty which is typically 1% to 2%. The total lo uncertainty in the ATLAS-2 SUSIM irradiance measurement (130 nm to 410 nm) is 2% to 4%. For the ATLAS-3 mission, the performance of the instrument has been enhanced by an improved wavelength determination a new D2 lamp and power supply, and the addition of a filter wheel in place of a fixed entrance filter. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Andrews, MD (reprint author), HUGHES STX CORP,4400 FORBES BLVD,LANHAM,MD 20706, USA. NR 3 TC 3 Z9 3 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD MAY PY 1996 VL 32 IS 6 BP 629 EP 631 DI 10.1088/0026-1394/32/6/46 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UU321 UT WOS:A1996UU32100046 ER PT J AU Brueckner, GE Floyd, LE Lund, PA Prinz, DK VanHoosier, ME AF Brueckner, GE Floyd, LE Lund, PA Prinz, DK VanHoosier, ME TI Solar ultraviolet spectral-irradiance observations from the SUSTM-UARS experiment SO METROLOGIA LA English DT Article; Proceedings Paper CT 5th International Conference on Radiometry CY SEP 19-21, 1994 CL BERLIN, GERMANY SP Phys Tech Bundesanstalt AB The Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) instrument on board the Upper Atmosphere Research Satellite (UARS) has measured solar ultraviolet spectral-irradiance values since October 1991. The calibration and tracking methods are described. The intensity values have a precision of 1 % at wavelengths longer than 200 nm. Short-term ultraviolet (UV) variability is correlated with other chromospheric indices at wavelengths shorter than 280 nm. At longer wavelengths, this correlation changes gradually into an anticorrelation. There exists a long-term solar-cycle component at all wavelengths, which seems to be independent of the rotational modulation. The variability in the integrated UV from 110 nm to 300 nm amounts to 33% of the variability in the total solar irradiance. C1 INTERFEROMETR INC,VIENNA,VA 22182. COMPUTAT PHYS INC,FAIRFAX,VA 22031. RP Brueckner, GE (reprint author), USN,RES LAB,SPACE RES CTR,WASHINGTON,DC 20375, USA. NR 4 TC 8 Z9 8 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD MAY PY 1996 VL 32 IS 6 BP 661 EP 665 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA UU321 UT WOS:A1996UU32100053 ER PT J AU Lohrmann, DR AF Lohrmann, DR TI Manifold offers 94-GHz power distribution SO MICROWAVES & RF LA English DT Article RP Lohrmann, DR (reprint author), USN,RES LAB,CODE 5747,4555 OVERLOOK AVE SW,WASHINGTON,DC 20375, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PENTON PUBL INC PI CLEVELAND PA 1100 SUPERIOR AVE, CLEVELAND, OH 44114 SN 0745-2993 J9 MICROWAVES RF JI Microw. RF PD MAY PY 1996 VL 35 IS 5 BP 150 EP & PG 4 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA UL493 UT WOS:A1996UL49300019 ER PT J AU Baker, MS Armfield, F AF Baker, MS Armfield, F TI Preventing post-traumatic stress disorders in military medical personnel SO MILITARY MEDICINE LA English DT Article AB Medical personnel in military units are highly vulnerable to post-traumatic stress disorder. They are removed from their conventional identity, stature, and social support system, and are deprived of a sense of control and physical comforts. They then must witness and immerse themselves in the gruesome results of warfare. Ideal training of medical personnel includes training intact units and functional teams, training on the deployment platform, and desensitizing with real casualty management. Using stress inoculation techniques prior to casualty handling, and providing for post-event debriefing (Critical Incidence Stress Debriefing), will reduce the incidence of combat casualty-induced stress disorders. RP Baker, MS (reprint author), USN RESERVE,COMBAT ZONE 500,FLEET HOSP 21,SURG SERV,WALNUT CREEK,CA, USA. NR 16 TC 19 Z9 21 U1 0 U2 0 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 SN 0026-4075 J9 MIL MED JI Milit. Med. PD MAY PY 1996 VL 161 IS 5 BP 262 EP 264 PG 3 WC Medicine, General & Internal SC General & Internal Medicine GA UK237 UT WOS:A1996UK23700008 PM 8855055 ER PT J AU Lankin, KM AF Lankin, KM TI Audiogram consistency needed SO MILITARY MEDICINE LA English DT Letter RP Lankin, KM (reprint author), USN HOSP,PENSACOLA,FL 32512, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 SN 0026-4075 J9 MIL MED JI Milit. Med. PD MAY PY 1996 VL 161 IS 5 BP A5 EP A5 PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA UK237 UT WOS:A1996UK23700003 PM 8855050 ER PT J AU Chen, ZP Berkower, I Ching, WM Wang, RYH Alter, HJ Shih, JWK AF Chen, ZP Berkower, I Ching, WM Wang, RYH Alter, HJ Shih, JWK TI Identification of a murine CD4(+) T-lymphocyte response site in hepatitis C virus core protein SO MOLECULAR IMMUNOLOGY LA English DT Article DE HCV; truncated recombinant core proteins; immune responses; epitope mapping; H-2 congenic mice; T helper epitope ID NON-B-HEPATITIS; CHRONIC NON-A; POSTTRANSFUSION HEPATITIS; NUCLEOTIDE-SEQUENCE; IMMUNE-RESPONSE; ANTIGEN; INFECTION; ANTIBODY; CELLS; NUCLEOPROTEIN AB T cell response to a recombinant HCV truncated core protein (cp1-10) was measured in a proliferation assay. Based on a 10-fold greater response to this truncated core protein than to its shorter form (cp1-8), a predominant epitope was mapped to the carboxyl quarter of this sequence. This epitope was further mapped to a synthetic peptide corresponding to amino acids 121-140 of the core protein. The peptide was antigenic for T cells of all three H-2 types tested, H-2 r, b and d, and the proliferating T cells were CD4(+). Besides inducing specific proliferation in vitro, peptide aa121-140 can prime helper T cells in vivo. When boosted with core protein, mice primed with peptide produced 64-fold higher antibody titer than without priming in 1 week. The identification of a broadly immunogenic T cell helper epitope on core protein may be important for vaccine design against HCV. C1 NIH,WARREN G MAGNUSON CLIN CTR,DEPT TRANSFUS MED,BETHESDA,MD 20892. US FDA,CTR BIOL EVALUAT & RES,OFF VACCINE RES & REVIEW,IMMUNOREGULAT LAB,BETHESDA,MD 20852. USN,MED RES INST,DEPT INFECT DIS,BETHESDA,MD 20889. ARMED FORCES INST PATHOL,AMER REGISTRY PATHOL,WASHINGTON,DC 20306. NR 43 TC 4 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0161-5890 J9 MOL IMMUNOL JI Mol. Immunol. PD MAY-JUN PY 1996 VL 33 IS 7-8 BP 703 EP 709 DI 10.1016/0161-5890(96)00010-7 PG 7 WC Biochemistry & Molecular Biology; Immunology SC Biochemistry & Molecular Biology; Immunology GA VA418 UT WOS:A1996VA41800014 PM 8760282 ER PT J AU Doig, P Yao, RJ Burr, DH Guerry, P Trust, TJ AF Doig, P Yao, RJ Burr, DH Guerry, P Trust, TJ TI An environmentally regulated pilus-like appendage involved in Campylobacter pathogenesis SO MOLECULAR MICROBIOLOGY LA English DT Article ID ESCHERICHIA-COLI; JEJUNI INFECTION; SALMONELLA-ENTERITIDIS; ANTIGENIC VARIATION; COLONIZATION FACTOR; GENE-EXPRESSION; IDENTIFICATION; MODEL; FLAGELLA; CLONING AB Examination of strains of Campylobacter jejuni, Campylobacter coli, and Campylobacter fetus by electron microscopy revealed that they produced peritrichous pilus-like appendages when the bacteria were grown in the presence of bile salts. Various bile-salt supplements were used and it was found that deoxycholate and chenodeoxycholic acid caused a significant enhancement of pilus production and resulted in a highly aggregative phenotype. Morphologically, the pili were between 4 and 7 nm in width and were greater than 1 mu m in length. A gene, termed pspA, which encodes a predicted protein resembling protease IV of Escherichia coli, was identified in C. jejuni strain 81-176. A site-specific insertional mutation within this gene resulted in the loss of pilus synthesis as determined by electron microscopy. Insertions upstream and downstream of the gene had no effect on pilus production. The non-piliated mutant of strain 81-176 showed no reduction in adherence to or invasion of INT 407 cells in vitro. However, this mutant, while still possessing the ability to colonize ferrets, caused significantly reduced disease symptoms in this animal model. C1 UNIV VICTORIA, DEPT BIOCHEM & MICROBIOL, VICTORIA, BC V8W 3P6, CANADA. UNIV VICTORIA, CANADIAN BACTERIAL DIS NETWORK, VICTORIA, BC V8W 3P6, CANADA. USN, MED RES INST, ENTER DIS PROGRAM, BETHESDA, MD 20889 USA. US FDA, WASHINGTON, DC 20204 USA. NR 56 TC 38 Z9 39 U1 1 U2 3 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0950-382X EI 1365-2958 J9 MOL MICROBIOL JI Mol. Microbiol. PD MAY PY 1996 VL 20 IS 4 BP 885 EP 894 DI 10.1111/j.1365-2958.1996.tb02526.x PG 10 WC Biochemistry & Molecular Biology; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA UN988 UT WOS:A1996UN98800019 ER PT J AU Langland, RH Liou, CS AF Langland, RH Liou, CS TI Implementation of an E-epsilon parameterization of vertical subgrid-scale mixing in a regional model SO MONTHLY WEATHER REVIEW LA English DT Article ID ATMOSPHERIC BOUNDARY-LAYER; TURBULENCE CLOSURE-MODEL; FINITE-ELEMENT MODEL; COLD AIR OUTBREAK; NUMERICAL-SIMULATION; SENSITIVITY; PREDICTION; TRANSPORT; DESIGN; FLOW AB An E-epsilon parameterization of subgrid-scale vertical turbulent mixing has been installed in NORAPS (Navy Operational Regional Atmospheric Prediction System). The 1.5-order parameterization uses full prognostic equations for turbulence kinetic energy E and dissipation E with no mixing length I assumption. A stable numerical method has been developed to integrate the two prognostic equations; this method has time and memory requirements that are similar to first-order K-theory turbulence parameterization and avoids numerical instabilities reported with E-l (Mellor-Yamada level 2.5) schemes. The E-epsilon parameterization produces a more active mixed layer, compared to a first-order K-theory scheme. Improvements are noted in forecasts of mixed-layer depth and near-surface wind speed, with reduction or elimination of spurious noise in the predicted fields of temperature and wind that were related to deficiencies of the first-order K-theory parameterization. In a numerical simulation of the ERICA (Experiment on Rapidly Intensifying Storms over the Atlantic) IOP 5A storm, the E-epsilon parameterization provides an improved forecast of cyclone central pressure. The better cyclone forecast results primarily from more accurate prediction of wind speed near the surface and in the upper troposphere where first-order K theory may produce unrealistic vertical mixing of momentum and temperature. RP Langland, RH (reprint author), USN, RES LAB, MARINE METEOROL DIV, 7 GRACE HOPPER AVE, MONTEREY, CA 93943 USA. NR 41 TC 42 Z9 42 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAY PY 1996 VL 124 IS 5 BP 905 EP 918 DI 10.1175/1520-0493(1996)124<0905:IOAPOV>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ178 UT WOS:A1996UJ17800008 ER PT J AU Ruggiero, FH Sashegyi, KD Madala, RV Raman, S AF Ruggiero, FH Sashegyi, KD Madala, RV Raman, S TI The use of surface observations in four-dimensional data assimilation using a mesoscale model SO MONTHLY WEATHER REVIEW LA English DT Article ID NUMERICAL WEATHER-PREDICTION; 4-DIMENSIONAL DATA-ASSIMILATION; ANALYSIS SYSTEM; REGIONAL-ANALYSIS; SCALE ANALYSIS; REAL-TIME; GALE; CYCLOGENESIS; AIRCRAFT; SCHEME AB A system for the frequent intermittent assimilation of surface observations into a mesoscale model is described. The assimilation begins by transforming the surface observations to model coordinates. Next, the lowest-level model fields of potential temperature, relative humidity, u and v component winds, and surface pressure are updated by an objective analysis using the successive correction approach. The deviations of the analysis from the first guess at the lowest model layer are then used to adjust the other model layers within the planetary boundary layer. The PBL adjustment is carried out by using the model's values of eddy diffusivity, which are nudged to reflect the updated conditions, to determine the influence of the lowest-layer deviations on the other model layers. Results from a case study indicate that the frequent intermittent assimilation of surface data can provide superior mesoscale analyses and forecasts compared to assimilation of synoptic data only. The inclusion of the PBL adjustment procedure is an important part of generating the better forecasts. Extrapolation of the results here suggests that two-dimensional data can be successfully assimilated into a model provided there is a mechanism to smoothly blend the data into the third dimension. C1 PHILLIPS LAB, DIV ATMOSPHER SCI, BEDFORD, MA USA. N CAROLINA STATE UNIV, DEPT MARINE EARTH & ATMOSPHER SCI, RALEIGH, NC 27695 USA. RP Ruggiero, FH (reprint author), USN, RES LAB, REMOTE SENSING DIV, CODE 7225, 4555 OVERLOOK AVE SW, WASHINGTON, DC 20375 USA. NR 54 TC 30 Z9 41 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAY PY 1996 VL 124 IS 5 BP 1018 EP 1033 DI 10.1175/1520-0493(1996)124<1018:TUOSOI>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ178 UT WOS:A1996UJ17800014 ER PT J AU Surko, SW AF Surko, SW TI Why can't we get the lead out? A review of US Navy surface ship service life allowance for weight and stability SO NAVAL ENGINEERS JOURNAL LA English DT Article; Proceedings Paper CT ASNE Day 1996 CY MAR 13-15, 1996 CL WASHINGTON, DC SP Amer Soc Naval Engineers AB U.S. Navy surface ships are designed with service life allowances to accommodate growth throughout their careers without exceeding original weight and stability limits. Adopted in 1986, the current criteria provides from five to ten percent of full load departure weight margin and 0.5 to 2.5 feet of full load departure KG margin based on ship type. The previous criteria proved inadequate: only twenty percent of the surface fleet is classified in Stability Status I (no displacement or stability problems). Ships inevitably get heavier, and become less stable, as new equipment and systems are added above the center of gravity. This trend is exacerbated by undocumented weight growth, which further eats into the service life allowances. Rather than remove topside weight or add blisters in service, lead ballast is regularly used as the ''cheap fix'' to maintain or restore adequate stability at the cost of added weight. As a result, the surface fleet is currently carrying a total of 27, 711 tons of lead (and pig iron) ballast. But, with average installation costs exceeding $5000 per ton, lead ballast is not an inexpensive solution. If growth is necessary for the continued modernization of the surface fleet, inadequate service life allowance can lead to premature obsolescence of otherwise good hulls. This is particularly true for surface combatants. The current criteria was first applied in the design of the notably stockier DDG-51 Arleigh Burke Class destroyers, which have been provided with a ten percent of full load departure weight margin and a 1.0 foot of full load departure KG margin. Only time will tell if this service life allowance criteria is adequate, but early growth and previous trends for surface combatants are cause for some concern. C1 USN, SEA SYST COMMAND, WASHINGTON, DC 20376 USA. RP Surko, SW (reprint author), USN, SEA SYST COMMAND, WASHINGTON, DC 20376 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 117 EP 125 PG 9 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700020 ER PT J AU Whitcomb, CA Smith, AB AF Whitcomb, CA Smith, AB TI Submarine power sources for the mission - Comment SO NAVAL ENGINEERS JOURNAL LA English DT Editorial Material RP Whitcomb, CA (reprint author), USN,WASHINGTON,DC 20375, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 139 EP 144 PG 6 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700026 ER PT J AU Hockberger, WA AF Hockberger, WA TI Total system ship design in a supersystem framework SO NAVAL ENGINEERS JOURNAL LA English DT Article; Proceedings Paper CT ASNE Day 1996 CY MAR 13-15, 1996 CL WASHINGTON, DC SP Amer Soc Naval Engineers AB Naval architects are skilled at turning a set of ship performance requirements into the engineering description of a ship capable of meeting them. That is the technical side of the problem, and our ability to deal with it has steadily improved. But the ship design problem has other major aspects that must be dealt with just as competently if the ultimate result is to be the best, most cost-effective ship possible. This paper proposes some major changes in the way naval ship design is approached. It provides a high level description of the entire process of early stage ship design and in doing so expands considerably on the traditional boundaries of that process. It places that process in its larger context of mission requirements determination, operational effectiveness assessment, and program management review and control, all of which influence a ship's technical characteristics and capabilities. It outlines the various elements of analysis, design, estimating and assessment involved and shows how they are interrelated and must be worked interactively in a comprehensive and systematic process if an optimal ship design is to be achieved. Interwoven with this expanded design process is an expanded context for understanding the role of the ship being designed. This paper introduces the idea of a ''supersystem'' containing all the other operational systems, facilities and support infrastructure the new ship system will have to operate jointly and compatibly with. It explains why totalsystem design and optimization must be focused at the supersystem level and not merely at the level of the new ship itself. Since this expanded focus requires looking for factors and effects in areas that have not generally been thought relevant, some principles and guidelines for recognizing them are provided. The paper clarifies the issue of ''measures of effectiveness'' (MOEs) versus ''measures of performance'' (MOPs) and shows how each should be determined and used. It shows how high level MOEs and the design philosophy can be distilled from the mission requirements even before any technical design work has begun. The practical use of modeling and simulation in matching the MOPs of an alternative system concept against the MOEs required by the mission is discussed. C1 USN, SEA SYST COMMAND, WASHINGTON, DC 20376 USA. RP Hockberger, WA (reprint author), USN, SEA SYST COMMAND, WASHINGTON, DC 20376 USA. NR 7 TC 0 Z9 1 U1 1 U2 1 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 147 EP 166 PG 20 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700028 ER PT J AU Calvano, CN AF Calvano, CN TI Total system ship design in a supersystem framework - Comment SO NAVAL ENGINEERS JOURNAL LA English DT Editorial Material RP Calvano, CN (reprint author), USN,POSTGRAD SCH,WASHINGTON,DC 20350, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 167 EP 167 PG 1 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700029 ER PT J AU Kosman, RJ AF Kosman, RJ TI Problem resolution during life cycle maintenance: A case study - Comment SO NAVAL ENGINEERS JOURNAL LA English DT Editorial Material RP Kosman, RJ (reprint author), USN,UNDERSEA WARFARE CTR,WASHINGTON,DC 20350, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 177 EP 178 PG 2 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700033 ER PT J AU Upton, B AF Upton, B TI Engineering off-the-shelf solutions: A life cycle view - Comment SO NAVAL ENGINEERS JOURNAL LA English DT Editorial Material RP Upton, B (reprint author), USN,SEA SYST COMMAND,SEA 0422,WASHINGTON,DC 20362, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 191 EP 192 PG 2 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700037 ER PT J AU Jorgensen, EL AF Jorgensen, EL TI Standards-based IETMs: The key to integrated weapon system support - Comment SO NAVAL ENGINEERS JOURNAL LA English DT Editorial Material RP Jorgensen, EL (reprint author), USN,CTR SURFACE WARFARE,CARDEROCK DIV,FLEET USER SYST BRANCH,IETM PROGRAMS,WASHINGTON,DC 20350, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 197 EP 198 PG 2 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700040 ER PT J AU Honea, W AF Honea, W TI Standards-based IETMs: The key to integrated weapon system support - Comment SO NAVAL ENGINEERS JOURNAL LA English DT Editorial Material RP Honea, W (reprint author), USN,CTR SURFACE WARFARE,PHD DIV,WASHINGTON,DC 20350, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 198 EP 198 PG 1 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700041 ER PT J AU Sargent, DP AF Sargent, DP TI Affordability, logistics R&D and fleet systems - Comment SO NAVAL ENGINEERS JOURNAL LA English DT Editorial Material RP Sargent, DP (reprint author), USN,CTR SURFACE WARFARE,WASHINGTON,DC 20350, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 214 EP 214 PG 1 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700044 ER PT J AU Taylor, JL AF Taylor, JL TI Affordability, logistics R&D and fleet systems - Comment SO NAVAL ENGINEERS JOURNAL LA English DT Editorial Material RP Taylor, JL (reprint author), USN OPERAT,N43,WASHINGTON,DC 20350, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 214 EP 215 PG 2 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700045 ER PT J AU Cho, CP Krol, WP AF Cho, CP Krol, WP TI Feasibility study of a novel integrated electric motor/pump for underwater applications SO NAVAL ENGINEERS JOURNAL LA English DT Article; Proceedings Paper CT ASNE Day 1996 CY MAR 13-15, 1996 CL WASHINGTON, DC SP Amer Soc Naval Engineers AB This paper presents the results of a feasibility study of a novel electric motor/pump system that combines an axial field, permanent magnet motor with a centrifugal pump. This system, unique because the motor permanent magnet (PM) rotor and pump impeller vanes are a single unit, provides a compact, reliable, low-noise, and high-power-density electrically driven centrifugal pump suitable for underwater applications in which minimizing noise, vibration, and volume are major design objectives. Performance tradeoffs for the electromagnetic analysis were made by two- and three-dimensional finite element analysis (FEA) models in conjunction with a lumped parameter magnetic circuit model. The study results reveal that theoretically the new integrated electric motor/pump concept (1) provides up to seventy-three percent electromagnetic efficiency with a significantly reduced volume and weight and (2) substantially increases the power density and reliability with the potential for quiet and high performance. This study is also evidence that new concepts can be explored with expanded computer modeling and simulation techniques. RP Cho, CP (reprint author), USN,UNDERSEA WARFARE CTR,DIV NEWPORT,WASHINGTON,DC 20350, USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 233 EP 240 PG 8 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700051 ER PT J AU Theis, T Titus, S AF Theis, T Titus, S TI The development of permeable membrane air dehydrators for the US Navy SO NAVAL ENGINEERS JOURNAL LA English DT Article; Proceedings Paper CT ASNE Day 1996 CY MAR 13-15, 1996 CL WASHINGTON, DC SP Amer Soc Naval Engineers AB As part of a program to eliminate chronic, shipboard, low pressure air dehydrator problems a Navy-industry team consisting of the Navy, Newport News Shipbuilding and a permeable membrane manufacturer has developed a new generation of permeable membrane air dehydration equipment to replace the complex and unreliable desiccant units currently used. Permeable membrane dehydration is a new technology utilizing new polysulfone, semipermeable polymeric membranes specially designed to perform molecular separation of gaseous mixtures. This process has proven to be extremely reliable and cost effective. The successful development of the permeable membrane dehydrator from an SBIR concept to shipboard units is described. A review of the current dehydrators and system history that drove this program, and the benefits and payoffs of the new equipment, are presented. Results of the laboratory evaluation, shipboard evaluation and the fleet transition plan are addressed. RP Theis, T (reprint author), USN,CTR SURFACE WARFARE,DEPT POWER & AUXILIARY SYST,MECH SYST BRANCH,COMPRESSED AIR SYST GRP,WASHINGTON,DC 20350, USA. NR 4 TC 1 Z9 1 U1 1 U2 1 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 243 EP 260 PG 18 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700055 ER PT J AU Doerry, N Robey, H Amy, J Petry, C AF Doerry, N Robey, H Amy, J Petry, C TI Powering the future with the integrated power system SO NAVAL ENGINEERS JOURNAL LA English DT Article; Proceedings Paper CT ASNE Day 1996 CY MAR 13-15, 1996 CL WASHINGTON, DC SP Amer Soc Naval Engineers AB For the past four years, Advanced Surface Machinery Programs (SEA 03R2) has been developing the Integrated Power System (IFS) to reduce ship acquisition and life cycle costs while still meeting all ship performance requirements. IFS provides electrical power to ship service loads and electric propulsion for a wide range of ship applications including surface combatants, aircraft carriers, amphibious ships, auxiliary ships, sealift and high value commercial ships. IFS consists of an architecture and a family of modules from which affordable and high performance configurations can be developed for the full range of ship applications. Two years ago, the initial IFS concepts were presented at ASNE Day 1994. Since then, much has been learned through the Reduced Scale Advanced Development (RSAD) and Full Scale Advanced Development (FSAD) programs. This paper describes the fundamental IFS architecture, details the evolving ''family of modules'' and their interface standards, and outlines the ''Mass Customization'' based design process for achieving customer performance requirements with an affordable IPS configuration. RP Doerry, N (reprint author), USN,NEWPORT NEWS,VA 23606, USA. NR 18 TC 13 Z9 14 U1 0 U2 2 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 267 EP 279 PG 13 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700059 ER PT J AU Vaughters, T AF Vaughters, T TI Simulation modeling of LHA 1 Class cargo handling system - Comment SO NAVAL ENGINEERS JOURNAL LA English DT Editorial Material RP Vaughters, T (reprint author), NAVAL SURFACE WARFARE CTR,CARDEROCK DIV,MOBILE SUPPORT SYST PROGRAM OFF,CODE 102,SILVER SPRING,MD, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 295 EP 296 PG 2 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700065 ER PT J AU Miller, RE Lamontagne, RA AF Miller, RE Lamontagne, RA TI Test and analysis of missile exhaust effects on the Collective Protection System SO NAVAL ENGINEERS JOURNAL LA English DT Article; Proceedings Paper CT ASNE Day 1996 CY MAR 13-15, 1996 CL WASHINGTON, DC SP Amer Soc Naval Engineers AB The Collective Protection System (CPS) is a continuous-use system designed to provide protection to personnel and work spaces within the ship from chemical, biological and radiological agents of hostile action. The CPS filter system consists of a High-Efficiency Particulate (HEPA) followed by an adsorbent impregnated charcoal. The CPS filter components are subjected to normal underway and exercise conditions (gases and vapors) that exist in the atmosphere surrounding the ship. The CPS can be subjected to missile exhaust, for which it was not specifically designed. CPS is a designed-in feature for new design ships. The USS Arleigh Burke was the first ship of a new class with a fully integrated CPS. Other new ship classes such as USS Wasp, USS Supply and USS Gunston Hall have CPS in living and selected working spaces. One purpose of this work was to determine if CPS filters removed or reduced missile toxicity levels in the ventilation supply to acceptable levels. A second purpose was to determine if the products of weapons exhaust damage or degrade the filters. An objective specific to the DDG 51 Class was to determine if the traditional Toxic Gas Damper systems could be eliminated. A series of land-based tests with live missiles, missile firings at-sea, and laboratory experiments were completed. The at-sea measurements were somewhat of a disappointment because favorable wind conditions were rarely available. The early work focused on the adsorbent charcoal. The results showed that the two-stage CPS filters adequately removed toxic levels of hydrogen chloride. There is evidence that the HEPA filter element alone may not adequately remove hydrogen chloride. It was concluded that elements of the CPS including filters, mixing/dilution, and ship geometry collectively prevent missile exhaust products from entering the ship. The degradation of the filters from missile firings is minimal and less than that of the natural marine atmosphere. The toxic gas dampers are not required when the two-stage filters are used. RP Miller, RE (reprint author), USN,RES LAB,ENVIRONM & CHEM SENSORS SECT,WASHINGTON,DC 20375, USA. NR 14 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 299 EP 312 PG 14 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700067 ER PT J AU Goodnow, MO Rumburg, JW AF Goodnow, MO Rumburg, JW TI Combat casualty simulation on shipboard electrical power systems (active demonstration) SO NAVAL ENGINEERS JOURNAL LA English DT Article; Proceedings Paper CT ASNE Day 1996 CY MAR 13-15, 1996 CL WASHINGTON, DC SP Amer Soc Naval Engineers AB For many years, electrical cable exposed to fragmentation was never taken into consideration in fault predictions for electrical power distribution systems. Testing, which began in 1990 by NSWC Annapolis under the Electrical Power Survivability Program, to evaluate the effects of combat casualty on electrical power distribution systems, verified that a condition of multiple simultaneous faults could occur from typical weapons threats. Four phases of testing were performed to characterize damage to electrical power cables. These four testing phases were severing a single energized power cable, fragmenting multiple power cables fed from a single source and fragmenting multiple power cables fed from multiple sources. This paper reviews the various phases of testing conducted from the inception of the program and the test results. RP Goodnow, MO (reprint author), NAVAL SURFACE WARFARE CTR,ELECT POWER SURVIVABIL PROGRAM,ANNAPOLIS,MD, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 335 EP 339 PG 5 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700075 ER PT J AU Headrick, JM Thomason, J AF Headrick, JM Thomason, J TI Naval applications of high frequency over-the-horizon radar SO NAVAL ENGINEERS JOURNAL LA English DT Article; Proceedings Paper CT ASNE Day 1996 CY MAR 13-15, 1996 CL WASHINGTON, DC SP Amer Soc Naval Engineers AB The Navy now has in operation a relatively new sensor, the AN/TPS-71 radar, that can provide wide area surveillance over a more than one million square mile area and out to ranges of 2000 nmi. This radar was procured primarily to support Naval Battle Groups by providing early warning of airborne threats. This radar is called ROTHR for Relocatable Over-The-Horizon Radar. In addition to the primary mission this type of radar has other capabilities including remote sea and weather sensing. HF radar that employs the ocean surface attached wave offers a means for detection of sea skimming missiles, aircraft, and ships at shorter but beyond line-of-sight ranges with a ship-borne installation. A current Advanced Technology Demonstration will show applicability of this sensor. RP Headrick, JM (reprint author), USN,RES LAB,HF OTH,WASHINGTON,DC 20375, USA. NR 7 TC 13 Z9 13 U1 1 U2 3 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 353 EP 359 PG 7 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700083 ER PT J AU Marshall, JT AF Marshall, JT TI Waterjet to Hull load transfer - Comment SO NAVAL ENGINEERS JOURNAL LA English DT Editorial Material RP Marshall, JT (reprint author), NAVAL SURFACE WARFARE CTR,CARDEROCK DIV,COMBATANT CRAFT DEPT,SILVER SPRING,MD, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAY PY 1996 VL 108 IS 3 BP 384 EP 385 PG 2 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA UW757 UT WOS:A1996UW75700093 ER PT J AU Woronko, GA StGermain, HA Meiers, JC AF Woronko, GA StGermain, HA Meiers, JC TI Effect of dentin primer on the shear bond strength between composite resin and enamel SO OPERATIVE DENTISTRY LA English DT Article AB The purpose of this investigation was to determine the effect of dentin primers from Scotchbond Multi-Purpose, ProBond, All-Bond 2, and Syntac on the shear bond strength of composite resin to etched enamel. Two groups of extracted human molar teeth with Battened enamel surfaces (n=12) were randomly assigned to each enamel/ dentin bonding system. Following manufacturers' instructions enamel surfaces were etched, rinsed, and dried. Composite bonding procedures were conducted similarly in both groups for each enamel/dentin bonding system, except that in one of the two groups, dentin primer was applied prior to adhesive resin and composite placement. Samples were thermocycled and tested in shear until failure. Fracture analysis was performed on enamel surfaces with both light and scanning electron microscopy. Shear bond values (Mean +/- SD, MPa) were: Scotchbond Multi-Purpose unprimed 22.4+/-3.2, primed 17.9+/-5.9; ProBond unprimed 19.4+/-6.2, primed 18.3+/-3.3; All-Bond 2 unprimed 19.0+/-3.6, primed 17.3+/-3.0; and Syntac unprimed 26.2+/-9.0, primed 22.0+/-5.4. The only significant difference found between primed and unprimed groups was with Purpose, though there was application to decrease enamel bond strengths. Fracture surface analysis revealed that most failures were cohesive within the composite resin. These data suggest that the effect of primer on bonded composite resin to etched enamel is material specific. RP Woronko, GA (reprint author), USN,SCH DENT,NATL NAVAL DENT CTR,BETHESDA,MD 20889, USA. NR 14 TC 23 Z9 24 U1 0 U2 0 PU UNIV WASHINGTON PI SEATTLE PA SCHOOL DENTISTRY SM-57, SEATTLE, WA 98195 SN 0361-7734 J9 OPER DENT JI Oper. Dent. PD MAY-JUN PY 1996 VL 21 IS 3 BP 116 EP 121 PG 6 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA UJ451 UT WOS:A1996UJ45100006 PM 9002871 ER PT J AU Weaver, BD Summers, GP Greene, RL Jackson, EM Mao, SN Jiang, W AF Weaver, BD Summers, GP Greene, RL Jackson, EM Mao, SN Jiang, W TI Radiation damage effects in Nd2-xCexCuO4-y thin films SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; TRANSITION-TEMPERATURE; ELECTRON-IRRADIATION; TC; DISORDER; DEGRADATION; SUPPRESSION; TRANSPORT; CRYSTALS; SURFACE AB We report on the effect of 4 MeV alpha-irradiation on the transition temperature T-c and critical current density j(c) of Nd2-xCexCuO4-y (NCCO) thin films. The same dependence of T-c and j(c) on the defect energy deposition is found for NCCO as for other irradiated cuprates, and is independent of large differences in the maximum T-c. The results strongly suggest that apical oxygen atom displacements do not contribute to the strong reduction of T-c, and that the main mechanism for T-c reduction is a depairing-like variation. C1 UNIV MARYLAND, DEPT PHYS, BALTIMORE, MD 21228 USA. UNIV MARYLAND, DEPT PHYS, CTR SUPERCOND RES, COLLEGE PK, MD 20742 USA. SFA INC, LANDOVER, MD 20785 USA. RP USN, RES LAB, CODE 6615, WASHINGTON, DC 20375 USA. NR 46 TC 11 Z9 11 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 EI 1873-2143 J9 PHYSICA C JI Physica C PD MAY 1 PY 1996 VL 261 IS 3-4 BP 229 EP 236 DI 10.1016/0921-4534(96)00185-2 PG 8 WC Physics, Applied SC Physics GA UP276 UT WOS:A1996UP27600008 ER PT J AU Chakarian, V Idzerda, YU Lin, HJ Gutierrez, C Prinz, GA Meigs, G Chen, CT AF Chakarian, V Idzerda, YU Lin, HJ Gutierrez, C Prinz, GA Meigs, G Chen, CT TI Canted coupling of buried magnetic multilayers SO PHYSICAL REVIEW B LA English DT Article ID CIRCULAR-DICHROISM; ULTRATHIN FILMS; SURFACE; FE(100); LAYERS; FE AB Soft-x-ray magnetic circular dichroism is used as an element-specific magnetometer to determine the magnetic behavior of a buried 4.3 monolayer Mn filmin a Fe25Co75/Mn/Fe25Co75 trilayer, which exhibits a 90 degrees coupling between the two ferromagnetic films. By measuring element-specific magnetic hysteresis curves for Fe, Co, and Mn along directions parallel and perpendicular to an applied magnetic field, the magnetization behavior of each element is described, indicating an anomalous in-plane canting of the net Mn moment with respect to the Fe and Co moments by 23 degrees. C1 USN,RES LAB,WASHINGTON,DC 20375. AT&T BELL LABS,MURRAY HILL,NJ 07974. SW TEXAS STATE UNIV,DEPT PHYS,SAN MARCOS,TX 78666. NR 26 TC 25 Z9 25 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1996 VL 53 IS 17 BP 11313 EP 11316 DI 10.1103/PhysRevB.53.11313 PG 4 WC Physics, Condensed Matter SC Physics GA UK250 UT WOS:A1996UK25000012 ER PT J AU Kresin, VZ Wolf, SA Ovchinnikov, YN AF Kresin, VZ Wolf, SA Ovchinnikov, YN TI Effect of pressure on T-c and the ''intrinsic'' T-c of cuprates SO PHYSICAL REVIEW B LA English DT Article ID SINGLE-CRYSTAL; SUPERCONDUCTING TRANSITION; THERMAL-EXPANSION; COPPER OXIDES; DEPENDENCE; TEMPERATURE; YBA2CU3O7; DENSITY; FIELD; T(C) AB We propose that the transition temperature in the layered cuprates is affected by a peculiar interplay between doping and pair-breaking scattering. This scattering can lead to a depression of T-c relative to its "intrinsic" value. Using this picture, one can explain the large value of T-c in the three-layered cuprates relative to the two- and one-layer cuprates and also understand the large pressure effects observed. We predict that one can raise T-c above the usual maximum value by applying pressure on underdoped TI-2201 samples and the maximum value of T-c under pressure is evaluated. The temperature dependence of the pressure coefficient is also discussed. C1 USN, RES LAB, WASHINGTON, DC 20375 USA. LD LANDAU THEORET PHYS INST, MOSCOW 11733V, RUSSIA. RP Kresin, VZ (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY NATL LAB, BERKELEY, CA 94720 USA. RI Wolf, Stuart/A-7513-2009 NR 59 TC 19 Z9 19 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1996 VL 53 IS 17 BP 11831 EP 11836 DI 10.1103/PhysRevB.53.11831 PG 6 WC Physics, Condensed Matter SC Physics GA UK250 UT WOS:A1996UK25000083 ER PT J AU Liu, X Steiner, MM Sooryakumar, R Prinz, GA Farrow, RFC Harp, G AF Liu, X Steiner, MM Sooryakumar, R Prinz, GA Farrow, RFC Harp, G TI Exchange stiffness, magnetization, and spin waves in cubic and hexagonal phases of cobalt SO PHYSICAL REVIEW B LA English DT Article ID FERROMAGNETIC-FILMS; EPITAXIAL-GROWTH; THERMAL MAGNONS; BCC COBALT; CO; FE; NI; SCATTERING; MAGNETISM; ALLOYS AB We utilize Brillouin light scattering to investigate the magnetic properties of the hexagonal-close-packed as well as the body- and face-centered cubic phases of elemental cobalt stabilized as thin epilayers. Expressions for the dependence of the surface and bulk magnons on applied magnetic field and in-plane propagation direction yield the exchange stiffness constant D, saturation magnetization M, and magnetic anisotropy fields of the cobalt atoms synthesized in these distinct crystal structures. Estimates of D and M are also calculated from the electronic band structure for the different crystalline phases. Satisfactory agreement is found between theory and experiment. The implications of these results towards our understanding of magnetic properties of itinerant ferromagnets are discussed. C1 USN,RES LAB,WASHINGTON,DC 20375. IBM CORP,ALMADEN RES CTR,SAN JOSE,CA 95120. RP Liu, X (reprint author), OHIO STATE UNIV,DEPT PHYS,174 W 18TH AVE,COLUMBUS,OH 43210, USA. NR 22 TC 61 Z9 61 U1 2 U2 15 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD MAY 1 PY 1996 VL 53 IS 18 BP 12166 EP 12172 DI 10.1103/PhysRevB.53.12166 PG 7 WC Physics, Condensed Matter SC Physics GA UK932 UT WOS:A1996UK93200042 ER PT J AU Ding, MZ Yang, WM In, V Ditto, WL Spano, ML Gluckman, B AF Ding, MZ Yang, WM In, V Ditto, WL Spano, ML Gluckman, B TI Controlling chaos in high dimensions: Theory and experiment SO PHYSICAL REVIEW E LA English DT Article ID DYNAMIC-SYSTEMS; LASER AB The main contribution of this work is the development of a high-dimensional chaos control method that is effective, robust against noise, and easy to implement in experiment. Assuming no knowledge of the model equations, the method achieves control by stabilizing a desired unstable periodic orbit with any number of unstable directions, using small time-dependent perturbations of a single system parameter. Specifically, our major results are as follows. First, we derive explicit control laws for time series produced by discrete maps. Second, we show how to apply this control law to continuous-time problems by introducing straightforward ways to extract from a continuous-time series a discrete time series that measures the dynamics of some Poincare map of the original system. Third, we illustrate our approach with two examples of high-dimensional ordinary differential equations, one autonomous and the other periodically driven. Fourth, we present the result on our successful control of chaos in a high-dimensional experimental system, demonstrating the viability of the method in practical applications. C1 FLORIDA ATLANTIC UNIV,DEPT MATH,BOCA RATON,FL 33431. GEORGIA INST TECHNOL,SCH PHYS,APPL CHAOS LAB,ATLANTA,GA 30332. USN,CTR SURFACE WARFARE,CARDEROCK DIV,SILVER SPRING,MD 20903. RP Ding, MZ (reprint author), FLORIDA ATLANTIC UNIV,CTR COMPLEX SYST,PROGRAM COMPLEX SYST & BRAIN SCI,BOCA RATON,FL 33431, USA. RI Spano, Mark/B-6883-2011; OI Ditto, William/0000-0002-7416-8012 NR 44 TC 64 Z9 64 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD MAY PY 1996 VL 53 IS 5 BP 4334 EP 4344 DI 10.1103/PhysRevE.53.4334 PN A PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA UM617 UT WOS:A1996UM61700021 ER PT J AU Grinstein, FF DeVore, CR AF Grinstein, FF DeVore, CR TI Dynamics of coherent structures and transition to turbulence in free square jets SO PHYSICS OF FLUIDS LA English DT Article ID ELLIPTIC JETS; MIXING LAYER; SHEAR FLOWS; SIMULATION; FIELD AB We report results of time-dependent numerical simulation of spatially developing free square jets initialized with a thin square vortex-sheet with slightly rounded corner-regions: The studies focus on the near field of jets with Mach number 0.3-0.6 and moderately high Reynolds numbers. A monotonically-integrated large-eddy-simulation approach is used, based on the solution of the unfiltered inviscid equations and appropriate inflow/outflow open boundary conditions. The simulations show that the initial development of the square jet is characterized by the dynamics of vortex rings and braid vortices. Farther downstream, strong vortex interactions lead to the breakdown of the vortices, and to a more disorganized flow regime characterized by smaller scale elongated vortices and spectral content consistent with that of the Kolmogorov (K41) inertial subrange. Entrainment rates significantly larger than those for round jets are directly related to the enhanced fluid and momentum transport between jet and surroundings determined by the vortex dynamics underlying the axis-rotation of the jet cross-section. The first axis-rotation of the jet cross-section can be directly correlated with self-induced vortex-ring deformation. However, subsequent jet axis-rotations are the result of strong interactions between ring and braid vortices, rather than being correlated with successive self-induced vortex-ring deformations, as previously conjectured based on laboratory observations. The interaction between braid and ring vortices has the effect of inhibiting the periodic self-induced axis-rotations observed in the case of isolated square vortex rings. (C) 1996 American Institute of Physics. RP Grinstein, FF (reprint author), USN,RES LAB,COMPUTAT PHYS & FLUID DYNAM LAB,WASHINGTON,DC 20375, USA. RI DeVore, C/A-6067-2015 OI DeVore, C/0000-0002-4668-591X NR 35 TC 88 Z9 89 U1 2 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD MAY PY 1996 VL 8 IS 5 BP 1237 EP 1251 DI 10.1063/1.868895 PG 15 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA UH305 UT WOS:A1996UH30500011 ER PT J AU Yadlowsky, EJ Moschella, JJ Hazelton, RC Settersten, TB Spanjers, GG Deeney, C Failor, BH LePell, PD Davis, J Apruzese, JP Whitney, KG Thornhill, JW AF Yadlowsky, EJ Moschella, JJ Hazelton, RC Settersten, TB Spanjers, GG Deeney, C Failor, BH LePell, PD Davis, J Apruzese, JP Whitney, KG Thornhill, JW TI Evidence for precursor plasma formation resulting from heterogeneous current channels in wire array loads SO PHYSICS OF PLASMAS LA English DT Article ID X-RAY-EMISSION AB The initial current flow in single and double wire loads exploded by current generators with dI/dt in the range of 10(10)-10(12) As has been investigated using laser absorption and interferometric techniques. The results clearly show heterogeneous current channel formation with a plasma corona surrounding a predominantly neutral core. In the two wire load case, the corona is observed to separate from the core and prematurely implode on axis. Parasitic current channels were observed when material, outgassed by a low level prepulse current, is ionized to form a current carrying plasma channel that temporarily shields the wire from the main current pulse. In a complementary study on a terawatt generator, the radiation spectra from Mg coated Al wire array loads contained Mg K-shell lines 10 ns before similar Al lines were observed, confirming the load straggling effects implied by the laser imaging measurements. The results are consistent with theoretical predictions of heterogeneous current channels and precursor plasma formation that lead to a softer implosion, reduced ion density, and reduced x-ray yield. (C) 1996 American Institute of Physics. C1 PHYS INT CO,SAN LEANDRO,CA 94577. USN,RES LAB,WASHINGTON,DC 20375. RP Yadlowsky, EJ (reprint author), HY TECH RES CORP,104 CTR COURT,RADFORD,VA 24141, USA. RI Settersten, Thomas/B-3480-2009 OI Settersten, Thomas/0000-0002-8017-0258 NR 19 TC 19 Z9 19 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1996 VL 3 IS 5 BP 1745 EP 1753 DI 10.1063/1.871693 PN 1 PG 9 WC Physics, Fluids & Plasmas SC Physics GA UK936 UT WOS:A1996UK93600031 ER PT J AU Obenschain, SP Bodner, SE Colombant, D Gerber, K Lehmberg, RH McLean, EA Mostovych, AN Pronko, MS Pawley, CJ Schmitt, AJ Sethian, JD Serlin, V Stamper, JA Sullivan, CA Dahlburg, JP Gardner, JH Chan, Y Deniz, AV Hardgrove, J Lehecka, T Klapisch, M AF Obenschain, SP Bodner, SE Colombant, D Gerber, K Lehmberg, RH McLean, EA Mostovych, AN Pronko, MS Pawley, CJ Schmitt, AJ Sethian, JD Serlin, V Stamper, JA Sullivan, CA Dahlburg, JP Gardner, JH Chan, Y Deniz, AV Hardgrove, J Lehecka, T Klapisch, M TI The Nike KrF laser facility: Performance and initial target experiments SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 37th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 06-10, 1995 CL LOUISVILLE, KY SP Amer Phys Soc, Div Plasma Phys ID INDUCED SPATIAL INCOHERENCE; RAYLEIGH-TAYLOR INSTABILITY; SCALE-LENGTH PLASMAS; SMOOTHING TECHNIQUES; BEAM; DRIVEN; ACCELERATION; IRRADIATION; UNIFORMITY; SCATTERING AB Krypton-fluoride (KrF) lasers are of interest to laser fusion because they have both the large bandwidth capability (>THz) desired for rapid beam smoothing and the short laser wavelength (1/4 mu m) needed for good laser-target coupling. Nike is a recently completed 56-beam KrF laser and target facility at the Naval Research Laboratory. Because of its bandwidth of 1 THz FWHM (full width at half-maximum). Nike produces more uniform focal distributions than any other high-energy ultraviolet laser. Nike was designed to study the hydrodynamic instability of ablatively accelerated planar targets. First results show that Nike has spatially uniform ablation pressures (Delta p/p<2%). Targets have been accelerated for distances sufficient to study hydrodynamic instability while maintaining good planarity. In this review we present the performance of the Nike laser in producing uniform illumination, and its performance in correspondingly uniform acceleration of targets. (C) 1996 American Institute of Physics. C1 SCI APPLICAT INT CORP,MCLEAN,VA 22102. ARTEP INC,COLUMBIA,MD 21045. RP Obenschain, SP (reprint author), USN,RES LAB,LAB COMPUTAT PHYS,CODE 6730 PLASMA PHYS DIV,WASHINGTON,DC 20375, USA. NR 38 TC 128 Z9 145 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1996 VL 3 IS 5 BP 2098 EP 2107 DI 10.1063/1.871661 PN 2 PG 10 WC Physics, Fluids & Plasmas SC Physics GA UK938 UT WOS:A1996UK93800041 ER PT J AU Hafizi, B Roberson, CW AF Hafizi, B Roberson, CW TI Role of beam quality in free-electron lasers SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 37th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 06-10, 1995 CL LOUISVILLE, KY SP Amer Phys Soc, Div Plasma Phys ID GAIN; EMITTANCE; WIGGLERS; REGIME AB A kinetic theory of the scaling of free-electron lasers is presented. The results are based on a variational solution of an eigenvalue equation that is derived from the Vlasov-Maxwell equations and includes the effects of optical guiding, betatron oscillations and emittance, energy spread, and self-fields. The dependence of growth rate and filling factor on betatron oscillations and emittance is displayed in terms of scaled variables. A scaled thermal velocity, S, is defined as a measure of axial beam quality and shown to provide a quantitative distinction between the cold and the kinetic regimes of operation. The possibility of enhancing the growth rate by compressing the beam longitudinally is explored and discussed on the basis of the variation of S. Finally, we discuss a surprising result. It is shown that self-fields, by opposing the betatron oscillations due to wiggler gradients, tend to reduce the spread in the axial velocity of the electrons. That is, self-fields effectively cool the beam. (C) 1996 American Institute of Physics. C1 OFF NAVAL RES,DIV PHYS SCI,ARLINGTON,VA 22217. ICARUS RES INC,BETHESDA,MD 20824. USN,RES LAB,DIV PLASMA PHYS,WASHINGTON,DC 20375. NR 16 TC 12 Z9 12 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1996 VL 3 IS 5 BP 2156 EP 2162 DI 10.1063/1.871669 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA UK938 UT WOS:A1996UK93800049 ER PT J AU Sprangle, P Esarey, E Krall, J AF Sprangle, P Esarey, E Krall, J TI Laser driven electron acceleration in vacuum, gases, and plasmas SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 37th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 06-10, 1995 CL LOUISVILLE, KY SP Amer Phys Soc, Div Plasma Phys ID ELECTROMAGNETIC-WAVES; PARTICLE-ACCELERATION; RAMAN-SCATTERING; TENUOUS PLASMAS; PULSES; GENERATION; RADIATION; BEAMS AB In this paper we discuss some of the important issues pertaining to laser acceleration in vacuum, neutral gases, and plasmas. The limitations of laser vacuum acceleration as they relate to electron slippage, laser diffraction, material damage, and electron aperture effects, are discussed. An inverse Cherenkov laser acceleration configuration is presented in which a laser beam is self-guided in a partially ionized gas. Optical self-guiding is the result of a balance between the nonlinear self-focusing properties of neutral gases and the diffraction effects of ionization. The stability of self-guided beams is analyzed and discussed. In addition, aspects of the laser wakefield accelerator are presented and laser-driven accelerator experiments are briefly discussed. (C) 1996 American Institute of Physics. RP Sprangle, P (reprint author), USN,RES LAB,DIV PLASMA PHYS,BEAM PHYS BRANCH,WASHINGTON,DC 20375, USA. NR 87 TC 116 Z9 117 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1996 VL 3 IS 5 BP 2183 EP 2190 DI 10.1063/1.871673 PN 2 PG 8 WC Physics, Fluids & Plasmas SC Physics GA UK938 UT WOS:A1996UK93800053 ER PT J AU Pecora, L AF Pecora, L TI Hyperchaos harnessed SO PHYSICS WORLD LA English DT Article RP Pecora, L (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 0 TC 21 Z9 23 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8585 J9 PHYS WORLD JI Phys. World PD MAY PY 1996 VL 9 IS 5 BP 17 EP 17 PG 1 WC Physics, Multidisciplinary SC Physics GA UJ567 UT WOS:A1996UJ56700017 ER PT J AU Hajian, AR Terzian, Y AF Hajian, AR Terzian, Y TI Planetary nebulae expansion distances .3. SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID NGC-6543; CATALOG; HALOES; VLA AB In a continuing project to determine accurate expansion-parallax distances to planetary nebulae, we have performed high-quality lambda 6-cm continuum observations of 12 nebulae with the Very Large Array. All of the sources in this imaging survey have one epoch of lambda 6-cm continuum data in the VLA archives. With two epochs for each planetary nebula, we applied the expansion parallax algorithm. Due in large part to the poor quality of the preexisting epoch, we were successful in only one case (NGC 7662), and obtained a lower limit to the distance for two PNe (Hu 1-2 and NGC 2440). Here, we also present new images acquired in this survey with the intent of reobserving the sample. Similar observations of these nebulae planned in 1997 should be sufficient to detect the expansion of a large percentage of the nebular shells. C1 CORNELL UNIV,NAIC,ITHACA,NY 14853. USN OBSERV,NRL,OPT INTERFEROMETER PROJECT,WASHINGTON,DC 20392. RP Hajian, AR (reprint author), CORNELL UNIV,DEPT ASTRON,ITHACA,NY 14853, USA. NR 34 TC 21 Z9 21 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD MAY PY 1996 VL 108 IS 723 BP 419 EP 425 DI 10.1086/133743 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UL015 UT WOS:A1996UL01500007 ER PT J AU Christianson, K Mittereder, J Roussos, J Anderson, WT AF Christianson, K Mittereder, J Roussos, J Anderson, WT TI Role of substrate current in the reliability life testing of GaAs MMICs SO QUALITY AND RELIABILITY ENGINEERING INTERNATIONAL LA English DT Article DE MMICs; substrate currents; high temperature life testing; reliability AB GaAs monolithic microwave integrated circuits (MMICs) typically show a dramatic increase in circuit current when operated above 200 degrees C. This increase in current has been found to be in good agreement ;with a summation of the estimated substrate current flowing from the individual components of these circuits through the bulk GaAs to the back metalization. Although the substrate current for these MMICs was small at room temperature, it can be a substantial portion of the total circuit current at the high temperatures typical for accelerated life testing. A procedure was developed to compensate for the substrate current, thus allowing normal circuit operation during high temperature life testing. RP Christianson, K (reprint author), USN,RES LAB,CODE 6855,WASHINGTON,DC 20375, USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0748-8017 J9 QUAL RELIAB ENG INT JI Qual. Reliab. Eng. Int. PD MAY-JUN PY 1996 VL 12 IS 3 BP 191 EP 194 PG 4 WC Engineering, Multidisciplinary; Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA UU401 UT WOS:A1996UU40100009 ER PT J AU Adams, JH Lee, J AF Adams, JH Lee, J TI A model of the primary cosmic ray spectra SO RADIATION MEASUREMENTS LA English DT Article ID SPACE EXPLORATION; MODULATION; RADIATION; NUCLEI AB We have collected published experimental measurements of the galactic cosmic ray spectra of the primary elements, H, He, C, O, Ne, Mg, Si and Fe in the energy range from 45 MeV/nucleon to 1 TeV/nucleon in the years 1963-1987. We have fit these data with a solution to the spherically symmetric diffusion equation using boundary spectra which are a solution of the cosmic ray propagation equation in the leaky-box model. In this work, we show how the energy spectra of these elements at 1AU are represented by this model. Copyright (C) 1996 Elsevier Science Ltd C1 GEORGE MASON UNIV,CS&I,FAIRFAX,VA 22032. RP Adams, JH (reprint author), USN,RES LAB,CODE 7654,WASHINGTON,DC 20375, USA. NR 17 TC 2 Z9 2 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1350-4487 J9 RADIAT MEAS JI Radiat. Meas. PD MAY PY 1996 VL 26 IS 3 BP 467 EP 470 DI 10.1016/1350-4487(96)00061-3 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VK744 UT WOS:A1996VK74400037 ER PT J AU Langworthy, JB AF Langworthy, JB TI The effects of critical charge variance on space upset rate SO RADIATION MEASUREMENTS LA English DT Article AB Sources of variance that may significantly affect space upset rate are analyzed and reduced to two main cases. Also, the current method of extracting critical charge from ground test data is noted to be inadequate for the most general case. Variance is propagated in the rounded shape model and applied to fitting the device cross section. The experience with this fitting generally supports the contribution of variance to the shape of the cross section. Then variance is propagated in the space upset rate and it is found that variance can be, but is not always, important. The result shows that variance is at least a nuisance, since it must be removed from the cross section in order to obtain model parameters. RP Langworthy, JB (reprint author), USN,RES LAB,CODE 6613,WASHINGTON,DC 20375, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1350-4487 J9 RADIAT MEAS JI Radiat. Meas. PD MAY PY 1996 VL 26 IS 3 BP 503 EP 508 DI 10.1016/1350-4487(96)00055-8 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VK744 UT WOS:A1996VK74400044 ER PT J AU Adams, JH Beliaev, AA Kuznetsov, NV Nymmik, RA Smith, EC AF Adams, JH Beliaev, AA Kuznetsov, NV Nymmik, RA Smith, EC TI Occurrence frequency of single event upsets induced on geosynchronous orbit: Model calculations and TDRS-1 experience SO RADIATION MEASUREMENTS LA English DT Article ID ENVIRONMENT; SEU AB Single event upset rate calculations using a galactic cosmic ray dynamic model and a simple single event upset (SEU) model were carried out. It is shown that the calculated SEU rate for the Fairchild 93L422 RAM chip on the TDRS-1 geosynchronous satellite in 1983-1991 is in good agreement with the experimental data. C1 MOSCOW MV LOMONOSOV STATE UNIV,SKOBELTSYN INST NUCL PHYS,MOSCOW 119899,RUSSIA. RP Adams, JH (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 17 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1350-4487 J9 RADIAT MEAS JI Radiat. Meas. PD MAY PY 1996 VL 26 IS 3 BP 509 EP 512 DI 10.1016/1350-4487(96)00050-9 PG 4 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VK744 UT WOS:A1996VK74400045 ER PT J AU Sorathia, U Lyon, R Gann, R Gritzo, L AF Sorathia, U Lyon, R Gann, R Gritzo, L TI Materials and fire threat SO SAMPE JOURNAL LA English DT Article C1 FAA,TECH CTR FIRE RES,ATLANTIC CITY INTL AIRPO,NJ. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Sorathia, U (reprint author), USN,CTR SURFACE WARFARE,CARDEROCK DIV,ANNAPOLIS,MD 21402, USA. NR 22 TC 29 Z9 29 U1 1 U2 2 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 SN 0091-1062 J9 SAMPE J JI Sampe J. PD MAY-JUN PY 1996 VL 32 IS 3 BP 8 EP 15 PG 8 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WT384 UT WOS:A1996WT38400003 ER PT J AU Caplan, I Sorathia, U Rollhauser, C AF Caplan, I Sorathia, U Rollhauser, C TI US Navy R&D programs in fire performance of materials SO SAMPE JOURNAL LA English DT Article AB Under the Office of Naval Research (ONR) and Naval Sea Systems Command (NAVSEA) sponsorship, the Naval Surface Warfare Center/Carderock Division (NSWC/CD) and the Naval Research Laboratory (NRL) have been studying fire related issues for composite materials in collaboration with industry, universities, research institutions, and other government agencies. The application of composite in U.S. Navy ships offers the potential for significant reductions in weight and signatures. Furthermore, the excellent seawater corrosion resistance of certain composite material systems can significantly reduce maintenance and life cycle costs. To quantify these benefits, the Navy has designed and built prototype structures and validated their performance consistent with critical mission requirements, such as shock and fire resistance. This paper highlights material development programs focused in the area of fire performance, prediction and prevention. It is the goal of these efforts to establish an understanding of how critical composite structures will perform during a fire, identify new materials to fire harden composites, and develop predictive methods for assessing post-fire thermal damage. An essential product of this program will be analytical tools for the design community to ensure structural integrity and fire safe designs for Navy ships. The technologies derived from these research and development programs generally are transitioned to shipboard applications through advanced development and/or technology demonstration projects. Examples of such projects will be briefly discussed with emphasis on cost effective solutions that make transition of advanced composites technology to the Fleet easier, faster, and safer. RP Caplan, I (reprint author), USN,CTR SURFACE WARFARE,CARDEROCK DIV,ANNAPOLIS,MD 21402, USA. NR 29 TC 5 Z9 5 U1 1 U2 3 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 SN 0091-1062 J9 SAMPE J JI Sampe J. PD MAY-JUN PY 1996 VL 32 IS 3 BP 21 EP 28 PG 8 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WT384 UT WOS:A1996WT38400005 ER PT J AU Ellis, JW Miller, JE Fernandez, MR AF Ellis, JW Miller, JE Fernandez, MR TI NRL's Tactical Oceanography Simulation Lab SO SEA TECHNOLOGY LA English DT Article C1 PLANNING SYST INC,BAY ST LOUIS,MS. RP Ellis, JW (reprint author), USN,ACOUST SIMULAT & TACT BRANCH,RES LAB,BAY ST LOUIS,MS, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD MAY PY 1996 VL 37 IS 5 BP 31 EP 37 PG 7 WC Engineering, Ocean SC Engineering GA UL398 UT WOS:A1996UL39800005 ER PT J AU Rockstad, HK Tang, TK Reynolds, JK Kenny, TW Kaiser, WJ Gabrielson, TB AF Rockstad, HK Tang, TK Reynolds, JK Kenny, TW Kaiser, WJ Gabrielson, TB TI A miniature, high-sensitivity, electron tunneling accelerometer SO SENSORS AND ACTUATORS A-PHYSICAL LA English DT Article; Proceedings Paper CT 8th International Conference on Solid-State Sensors and Actuators (Eurosensors IX) CY JUN 25-29, 1995 CL STOCKHOLM, SWEDEN DE electron tunneling; accelerometers; micromachining; hydrophones; acoustic sensors ID DETECTOR; SENSOR; TRANSDUCER; NOISE AB Prototype low-noise miniature accelerometers have been fabricated with electron-tunneling transducers. The electron-tunneling transducer permits detection of small displacements of the proof mass with high electrical response; such a transducer is essential for a high-performance miniature accelerometer. Prototype accelerometers have shown self-noise of approximately 10(-7) g (Hz)(-1/2) or less between 10 and 200 Hz, and close to 10(-8) g (Hz)(-1/2) near the resonance frequency of 100 Hz. Directivity measurements give nulls at least 50 dB below the maximum. A dual-axis prototype designed for underwater acoustic applications is packaged in an 8 cm(3) volume with a mass of 8 g. C1 STANFORD UNIV,DEPT MECH ENGN,STANFORD,CA 94305. UNIV CALIF LOS ANGELES,DEPT ELECT ENGN,LOS ANGELES,CA 90024. USN,AIR WARFARE CTR,DIV AIRCRAFT,WARMINSTER,PA 18974. RP Rockstad, HK (reprint author), CALTECH,CTR SPACE MICROELECTR TECHNOL,JET PROPULS LAB,PASADENA,CA 91109, USA. NR 18 TC 21 Z9 28 U1 2 U2 12 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0924-4247 J9 SENSOR ACTUAT A-PHYS JI Sens. Actuator A-Phys. PD MAY PY 1996 VL 53 IS 1-3 BP 227 EP 231 DI 10.1016/0924-4247(96)01128-4 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA UV649 UT WOS:A1996UV64900002 ER PT J AU Fang, JD Tooley, D Gatewood, C Renegar, KB Majde, JA Krueger, JM AF Fang, JD Tooley, D Gatewood, C Renegar, KB Majde, JA Krueger, JM TI Differential effects of total and upper airway influenza viral infection on sleep in mice SO SLEEP LA English DT Article DE sleep; NREM sleep; REM sleep; EEG; influenza; virus; mice ID DOUBLE-STRANDED-RNA; FATIGUE SYNDROME; VIRUS; INTERFERON; INDUCTION; MODEL AB Sleepiness is a common perception during most infectious diseases, including viral infections. Previously, we observed that a lethal strain of influenza virus (H1N1) causes a greater increase in non-rapid eye movement sleep (NREMS) than a nonlethal strain of influenza virus (H3N2), suggesting that the magnitude of sleep responses after viral inoculation depends on the severity of the infection. The aim of the present experiment was to further test this possibility. The effects of total airway infection versus upper airway infection on sleep were tested in two groups of mice using the same strain of virus (H1N1). After 2-3 days of baseline sleep recordings, Swiss-Webster mice were infected intranasally with H1N1 influenza virus. Sleep was determined again for an additional 3 days and 6 hours. Total airway infection significantly increased NREMS beginning about 24 hours after the viral inoculation and significantly suppressed rapid eye movement sleep (REMS) with a longer latency. Both the increase in NREMS and the decrease in REMS lasted until the end of the experiment. Total airway infection also significantly decreased the body weight of the mice. In contrast, upper airway infection did not induce clear changes in sleep and body weight. C1 UNIV TENNESSEE,CTR HLTH SCI,DEPT PHYSIOL & BIOPHYS,MEMPHIS,TN 38163. OFF NAVAL RES,ARLINGTON,VA 22217. NR 25 TC 8 Z9 8 U1 0 U2 1 PU AMER SLEEP DISORDERS ASSOC PI ROCHESTER PA 1610 14TH STREET NW SUITE 300, ROCHESTER, MN 55806 SN 0161-8105 J9 SLEEP JI Sleep PD MAY PY 1996 VL 19 IS 4 BP 337 EP 342 PG 6 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA UP605 UT WOS:A1996UP60500011 ER PT J AU Muradov, NZ TRaissi, A Muzzey, D Painter, CR Kemme, MR AF Muradov, NZ TRaissi, A Muzzey, D Painter, CR Kemme, MR TI Selective photocatalytic destruction of airborne VOCs SO SOLAR ENERGY LA English DT Article ID OXIDATION AB This article describes a photocatalytic method for selective oxidation of the airborne nitroglycerine (NG), in the presence of ethanol and acetone vapors at high concentrations (exceeding 1% by volume). Process selectivities toward NG photooxidation were examined for various photoreactor configurations and UV lamps and techniques used for the photocatalyst preparation. In addition, we have studied the effect of temperature, residence time, various additives (e.g. ozone, water vapor, nitrogen), and initial concentration of the solvents in air. Our data indicate that modifying TiO2 with silico-tungstic acid (STA) catalyst results in selective NG oxidation without affecting ethanol and acetone significantly. Platinization of TiO2 showed an adverse effect on NG destruction selectivity. In general, low residence times and initial concentration of oxidants and high temperatures and initial concentration of solvents favor selectivity toward NG destruction. In the case of temperature, our observation can be explained by the temperature dependent gas diffusion and surface processes. In most cases, the yield of ethanol oxidation was generally higher than that of acetone. Results from the bench-scale experiments using artificial UV light sources were used to build and test a solar photocatalytic oxidation reactor for selective NG treatment in the presence of ethanol and acetone. Copyright (C) 1996 Elsevier Science Ltd. C1 UNIV CENT FLORIDA,FLORIDA SOLAR ENERGY CTR,COCOA,FL 32922. USN,CTR SURFACE WARFARE,INDIAN HEAD,MD 20640. USA,CONSTRUCT ENGN RES LABS,CHAMPAIGN,IL 61826. NR 16 TC 15 Z9 15 U1 2 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-092X J9 SOL ENERGY JI Sol. Energy PD MAY PY 1996 VL 56 IS 5 BP 445 EP 453 DI 10.1016/0038-092X(96)00031-X PG 9 WC Energy & Fuels SC Energy & Fuels GA VB381 UT WOS:A1996VB38100009 ER PT J AU Singh, DJ AF Singh, DJ TI Phonons in La2CuO4: Local density calculations SO SOLID STATE COMMUNICATIONS LA English DT Article DE high-T-c superconductors; phonons ID SINGLE-CRYSTAL LA2-XSRXCUO4; HIGH-TC SUPERCONDUCTIVITY; LATTICE INSTABILITY; LA2-XBAXCUO4 AB A full set of zone center phonon frequencies and polarization vectors of tetragonal I4/mmm La2CuO4 are determined using local density approximation calculations. Reasonable agreement with experimental frequencies is obtained for modes that do not involve c-axis motions of the plane O atoms or motions of the apical O atoms parallel to the CuO2 planes. The modes that do involve such displacements have frequencies that are lower than experiment. This is understood in terms of stiffening of these modes due to tilts of the octahedra in the actual structure. Two soft Gamma point modes involving the apical O are found. However, the Gamma point instability is much weaker than the X point tilt mode. RP Singh, DJ (reprint author), USN,RES LAB,COMPLEX SYST THEORY BRANCH,WASHINGTON,DC 20375, USA. RI Singh, David/I-2416-2012 NR 22 TC 9 Z9 9 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD MAY PY 1996 VL 98 IS 6 BP 575 EP 579 DI 10.1016/0038-1098(95)00827-6 PG 5 WC Physics, Condensed Matter SC Physics GA UG736 UT WOS:A1996UG73600019 ER PT J AU Edmondson, CA Wintersgill, MG Fontanella, JJ Gerace, F Scrosati, B Greenbaum, SG AF Edmondson, CA Wintersgill, MG Fontanella, JJ Gerace, F Scrosati, B Greenbaum, SG TI High pressure NMR and electrical conductivity studies of gel electrolytes based on poly(acrylonitrile) SO SOLID STATE IONICS LA English DT Article DE high pressure; electrical conductivity; nuclear magnetic resonance; gels; complex impedance ID POLYMER AB The effect of high pressure on electrical conductivity and NMR in gels prepared from lithium or sodium perchlorate, ethylene carbonate, dimethyl carbonate and poly(acrylonitrile) (PAN) has been determined. The corresponding liquids were also studied. Complex impedance studies at frequencies from 10 to 10(8) Hz and NMR measurements of T-1 were carried out as a function of pressure up to 0.25 GPa. Activation volumes for NMR relaxation and ionic conductivity were calculated from the variable pressure data. Both activation volumes were found to be approximately the same in the liquids. For the gels, however, the NMR activation volumes are the same or lower than for the liquid while the electrical conductivity pressure dependences are larger. The implications of these results are discussed in terms of possible effects of the PAN on the ionic solvation shell. C1 USN ACAD,DEPT PHYS,ANNAPOLIS,MD 21402. UNIV ROMA LA SAPIENZA,DEPT CHEM,ROME,ITALY. CUNY HUNTER COLL,DEPT PHYS,NEW YORK,NY 10021. NR 12 TC 29 Z9 29 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 J9 SOLID STATE IONICS JI Solid State Ion. PD MAY PY 1996 VL 85 IS 1-4 BP 173 EP 179 DI 10.1016/0167-2738(96)00055-0 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA VF865 UT WOS:A1996VF86500024 ER PT J AU Voge, VM AF Voge, VM TI Secondary arterial hypertension linked to freon exposure SO SOUTHERN MEDICAL JOURNAL LA English DT Article ID KIDNEY; SOLVENTS AB Freons are generally considered to be minimally toxic, There are no reports in the literature of Freons causing secondary arterial hypertension. We report two cases of acute, massive Freon exposure that preceded secondary arterial hypertension, We hypothesize that the arterial hypertension was precipitated by renal proximal tubular damage, although several other mechanisms are possible. C1 USN,SCH HLTH SCI,BETHESDA DETACHMENT,FT SAM HOUSTON,TX. NR 21 TC 3 Z9 3 U1 0 U2 0 PU SOUTHERN MEDICAL ASSN PI BIRMINGHAM PA 35 LAKESHORE DR PO BOX 190088, BIRMINGHAM, AL 35219 SN 0038-4348 J9 SOUTHERN MED J JI South.Med.J. PD MAY PY 1996 VL 89 IS 5 BP 516 EP 518 DI 10.1097/00007611-199605000-00014 PG 3 WC Medicine, General & Internal SC General & Internal Medicine GA UJ522 UT WOS:A1996UJ52200014 PM 8638181 ER PT J AU Hubler, GK Sprague, JA AF Hubler, GK Sprague, JA TI Energetic particles in PVD technology: Particle-surface interaction processes and energy-particle relationships in thin film deposition SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 1st Australia/US Workshop on Critical Issues in High Performance Wear Resistant Films CY FEB 01-03, 1995 CL WOLLONGONG, AUSTRALIA SP CSIRO, Div Appl Phys, Lindfield NSW, Sutton Tools, Thomastown Vic, Sola Int Holdings, Adelaide SA, Broken Hill Pty, Port Kembla NSW DE ion bombardment; physical vapor deposition; film nucleation; film growth ID BEAM ASSISTED DEPOSITION; MOLECULAR-DYNAMICS; ION-BOMBARDMENT; GROWTH; NUCLEATION AB Energetic deposition techniques, including ion beam assisted deposition, ion plating, unbalanced magnetron sputtering, and cathodic-arc deposition, are playing an increasing role in the processing of coatings for mechanical, optical, and electronic applications, and for the protection of surfaces in hostile environments. Advantages of energetic film deposition include low temperature processing, improved adhesion to substrates, production ol desired phases or compounds, and control of crystallographic orientation. There are certain fundamental physical processes common to these energetic deposition methods that involve the alloying of elements (ion implantation, condensate and gas adsorption), material removal (sputtering, desorption), collision-induced displacements, collision-stimulated thermal exchange, and collision-induced surface and bulk diffusion. The mechanisms by which these mechanisms affect film formation are under intense investigation. New Monte Carlo and molecular dynamics simulations of the effects of energetic atoms on surfaces as well as experimental investigations revealing relationships between deposition variables and phase formation are contributing to our understanding of thin film growth. This paper covers the above topics by first establishing the 'ideal' conditions for deposition of a film, indicates how different deposition processes attempt to approximate these conditions, and reviews known correlations between deposition variables and film characteristics. C1 USN,RES LAB,WASHINGTON,DC 20375. NR 19 TC 27 Z9 30 U1 1 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY PY 1996 VL 81 IS 1 BP 29 EP 35 DI 10.1016/0257-8972(95)02617-7 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA UQ992 UT WOS:A1996UQ99200006 ER PT J AU Legg, KO Graham, M Chang, P Rastagar, F Gonzales, A Sartwell, B AF Legg, KO Graham, M Chang, P Rastagar, F Gonzales, A Sartwell, B TI The replacement of electroplating SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 1st Australia/US Workshop on Critical Issues in High Performance Wear Resistant Films CY FEB 01-03, 1995 CL WOLLONGONG, AUSTRALIA SP CSIRO, Div Appl Phys, Lindfield NSW, Sutton Tools, Thomastown Vic, Sola Int Holdings, Adelaide SA, Broken Hill Pty, Port Kembla NSW DE electroplating; chrome; physical vapor deposition; HVOF AB With the increasing concern over toxic wastes produced by conventional metal finishing operations there is a strong drive in the USA to replace ''dirty'' electroplating processes (especially chrome and cadmium) with ''clean'' technologies. While many companies and military agencies continue to think in terms of less polluting electroplates, others are turning away from bath technologies completely, in favor of the modern high performance dry coating methods such as physical vapor deposition (PVD), chemical vapor deposition (CVD) and thermal spraying. Under funding from the US Defense Department's Advanced Research Projects Agency, various dry alternatives to electrolytic hard chrome, namely PVD, plasma nitriding, high velocity oxyfuel (HVOF), laser CVD and laser cladding, have been examined for use both in original equipment manufacture and in rebuilding worn components. In this paper hard chrome replacement is used to illustrate the requirements for replacement of electrolytic coatings in general. Hard chrome alternatives are being evaluated to ensure not only that their performance is at least comparable with the chrome they replace, but also that they fit with the way in which the coated components are produced, used, and refurbished. They must be reliable and cost-effective, and must fit the needs of the end user over the entire life cycle of the coated component. HVOF, PVD and duplex plasma-nitride PVD coatings show great promise as replacements in a variety of applications, from bearing surfaces and hydraulics to decorative finishes. The combination of performance data with cost analyses shows that these alternatives can be cost-effective chrome replacements. For example, HVOF coatings can provide more than twice the life in sliding wear at half the cost. C1 CUMMINS PISTON RING DIV,CHARLESTON,SC 29405. CORPUS CHRISTI ARMY DEPOT,CORPUS CHRISTI,TX 78419. USN,RES LAB,WASHINGTON,DC 20375. RP Legg, KO (reprint author), NORTHWESTERN UNIV,BIRL,1801 MAPLE AVE,EVANSTON,IL 60201, USA. RI Graham, Michael/B-7518-2009 NR 7 TC 53 Z9 57 U1 0 U2 16 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY PY 1996 VL 81 IS 1 BP 99 EP 105 DI 10.1016/0257-8972(95)02653-3 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA UQ992 UT WOS:A1996UQ99200014 ER PT J AU Cotell, CM Hirvonen, JK AF Cotell, CM Hirvonen, JK TI Effect of ion energy on the mechanical properties of ion beam assisted deposition (IBAD) wear resistant coatings SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 1st Australia/US Workshop on Critical Issues in High Performance Wear Resistant Films CY FEB 01-03, 1995 CL WOLLONGONG, AUSTRALIA SP CSIRO, Div Appl Phys, Lindfield NSW, Sutton Tools, Thomastown Vic, Sola Int Holdings, Adelaide SA, Broken Hill Pty, Port Kembla NSW DE ion beam assisted deposition; wear resistant coatings; ion energy; compressive stress; void densification; adhesion ID THIN-FILM ORIENTATION; DIAMOND-LIKE CARBON; MOLECULAR-DYNAMICS; INTERNAL-STRESSES; TIN FILMS; COMPRESSIVE STRESS; VAPOR-PHASE; METAL-FILMS; AG-ATOMS; GROWTH AB Ion beam assisted physical vapor deposition offers a number of advantages over other surface modification methods with respect to the properties of wear resistant coatings. These properties include density, adhesion to the substrate, crystallographic orientation, durability and resistance to degradation by moisture. These improved film properties derive from the physical and chemical processes associated with the impingement of energetic ions onto the surface of a growing film. Such processes include sputtering and desorption of atoms from the substrate, implantation of atoms into the substrate, chemical reactions at the surface, cluster nucleation and dissociation, enhancement of surface diffusion, atomic displacements in the bulk, as well as energy and momentum transfer to the atoms in the growing film. A review of models for the influence of ion energy and momentum transfer to a growing film suggests that the effects of ion bombardment may be categorized according to the ion energy. C1 USA,RES LAB,MAT DIRECTORATE,CC,AMSRL,ABERDEEN PROVING GROUND,MD 21005. RP Cotell, CM (reprint author), USN,RES LAB,SURFACE MODIFICAT BRANCH,CODE 6670,WASHINGTON,DC 20375, USA. NR 70 TC 16 Z9 18 U1 0 U2 6 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD MAY PY 1996 VL 81 IS 1 BP 118 EP 125 DI 10.1016/0257-8972(95)02650-9 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA UQ992 UT WOS:A1996UQ99200016 ER PT J AU Bradshaw, DA Murray, KM Amundson, DE AF Bradshaw, DA Murray, KM Amundson, DE TI Spontaneous regression of a giant pulmonary bulla SO THORAX LA English DT Article DE emphysema; giant bulla; spontaneous regression; pulmonary function AB Gradual expansion of a lung bulla is common and may be associated with debilitating pulmonary symptoms. The aetiology of bulla expansion is unclear. Spontaneous regression, on the other hand, is rarely observed. The case is presented of a man in whom near complete spontaneous resolution of a giant pulmonary bulla occurred, This event was associated with dramatic improvement in the radiographic picture and pulmonary function. C1 USN,MED CTR,DEPT CLIN INVEST,DEPT CRIT CARE MED,SAN DIEGO,CA 92134. RP Bradshaw, DA (reprint author), USN,MED CTR,DEPT CLIN INVEST,DEPT INTERNAL MED,DIV PULM,SAN DIEGO,CA 92134, USA. NR 10 TC 9 Z9 9 U1 0 U2 0 PU BRITISH MED JOURNAL PUBL GROUP PI LONDON PA BRITISH MED ASSOC HOUSE, TAVISTOCK SQUARE, LONDON, ENGLAND WC1H 9JR SN 0040-6376 J9 THORAX JI Thorax PD MAY PY 1996 VL 51 IS 5 BP 549 EP 550 DI 10.1136/thx.51.5.549 PG 2 WC Respiratory System SC Respiratory System GA UK088 UT WOS:A1996UK08800021 PM 8711689 ER PT J AU Rodier, GR Gubler, DJ Cope, SE Cropp, CB Soliman, AK Polycarpe, D Abdourhaman, MA Parra, JP Maslin, J Arthur, RR AF Rodier, GR Gubler, DJ Cope, SE Cropp, CB Soliman, AK Polycarpe, D Abdourhaman, MA Parra, JP Maslin, J Arthur, RR TI Epidemic dengue 2 in the city of Djibouti 1991-1992 SO TRANSACTIONS OF THE ROYAL SOCIETY OF TROPICAL MEDICINE AND HYGIENE LA English DT Article DE dengue 2; Djibouti ID ORIGINAL ANTIGENIC SIN; SEROLOGICAL EVIDENCE; INFECTIONS; FEVER; ANTIBODIES; VIRUSES AB From October 1991 to February 1992, an outbreak of acute fever (in which thick blood films were negative for malaria) spread rapidly in the city of Djibouti, Djibouti Republic, affecting all age groups and both nationals and foreigners. The estimated number of cases was 12000. The clinical features were consistent with a non-haemorrhagic dengue-like illness. Serum samples from 91 patients were analysed serologically for flavivirus infection (dengue 1-4, West Nile, yellow fever, Zika, Banzi, and Uganda-S), and virus isolation was attempted. Twelve strains of dengue 2 virus were isolated. Dengue infection was confirmed by a 4-fold or greater rise in immunoglobulin (Ig) G antibody in paired serum specimens, the presence of IgM antibody, or isolation of the virus. Overall, 46 of the suspected cases (51%) were confirmed virologically or had serological evidence of a recent flavivirus infection. Statistical analysis showed that the presence of a rash was the best predictor of flavivirus seropositivity. In November 1992, Aedes aegypti was widespread and abundant in several districts of Djibouti city. A serological study of serum samples collected from Djiboutian military personnel 5 months before the epidemic showed that only 15/177 (8.5%) had flavivirus antibodies. These findings, together with a negative serosurvey for dengue serotypes 1-4 and yellow fever virus performed in 1987, support the conclusion that dengue 2 virus has only recently been introduced to Djibouti. C1 USN,MED RES UNIT 3,CAIRO,EGYPT. UNIV MARYLAND,SCH MED,BALTIMORE,MD 21201. CTR DIS CONTROL & PREVENT,NATL CTR INFECT DIS,DIV VECTOR BORNE INFECT DIS,FT COLLINS,CO 80522. JOHNS HOPKINS UNIV,SCH HYG & PUBL HLTH,BALTIMORE,MD. NR 26 TC 23 Z9 23 U1 1 U2 13 PU ROYAL SOC TROPICAL MEDICINE PI LONDON PA MANSON HOUSE 26 PORTLAND PLACE, LONDON, ENGLAND W1N 4EY SN 0035-9203 J9 T ROY SOC TROP MED H JI Trans. Roy. Soc. Trop. Med. Hyg. PD MAY-JUN PY 1996 VL 90 IS 3 BP 237 EP 240 PG 4 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA UT794 UT WOS:A1996UT79400009 PM 8758061 ER PT J AU Dell, RF Batta, R Karwan, MH AF Dell, RF Batta, R Karwan, MH TI The multiple vehicle TSP with time windows and equity constraints over a multiple day horizon SO TRANSPORTATION SCIENCE LA English DT Article ID PUBLIC RISK; OPTIMIZATION; PERSPECTIVES AB This paper considers the multiple vehicle traveling salesman problem cast over a multiple day routing scenario, with time windows and equity constraints. It develops an optimal column generation procedure and heuristic variations which solve test problems derived from the overnight delivery business. Extensive empirical testing indicates the judicious chose of a few routes for each day can incorporate equity at little or no additional cost. C1 SUNY BUFFALO, DEPT IND ENGN, BUFFALO, NY 14260 USA. RP Dell, RF (reprint author), USN, POSTGRAD SCH, DEPT OPERAT RES, MONTEREY, CA 93943 USA. RI Karwan, Mark/H-5150-2016 OI Karwan, Mark/0000-0001-9478-6988 NR 20 TC 7 Z9 7 U1 1 U2 1 PU INFORMS PI HANOVER PA 7240 PARKWAY DR, STE 310, HANOVER, MD 21076-1344 USA SN 0041-1655 J9 TRANSPORT SCI JI Transp. Sci. PD MAY PY 1996 VL 30 IS 2 BP 120 EP 133 DI 10.1287/trsc.30.2.120 PG 14 WC Operations Research & Management Science; Transportation; Transportation Science & Technology SC Operations Research & Management Science; Transportation GA UP037 UT WOS:A1996UP03700003 ER PT J AU Weng, NP Levine, BL June, CH Hodes, RJ AF Weng, NP Levine, BL June, CH Hodes, RJ TI Regulated expression of telomerase activity in human T lymphocyte development and activation. SO FASEB JOURNAL LA English DT Meeting Abstract C1 NCI,NIH,EIB,BETHESDA,MD 20892. NIA,NIH,BETHESDA,MD 20892. USN,MED RES INST,ICBP,BETHESDA,MD 20889. RI Levine, Bruce/D-1688-2009 NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 30 PY 1996 VL 10 IS 6 BP 278 EP 278 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA UK861 UT WOS:A1996UK86100509 ER PT J AU Miller, GA DAlesandro, MM Euler, G AF Miller, GA DAlesandro, MM Euler, G TI Production of interleukin-6 by polymorphonuclear leukocytes in gingival and periradicular tissues. SO FASEB JOURNAL LA English DT Meeting Abstract C1 USN,SCH DENT,BETHESDA,MD 20889. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 30 PY 1996 VL 10 IS 6 BP 311 EP 311 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA UK861 UT WOS:A1996UK86100543 ER PT J AU Prasad, P Axley, MJ AF Prasad, P Axley, MJ TI Effects of oxygen and flavin mononucleotide on the activity of rat neuronal nitric oxide synthase. SO FASEB JOURNAL LA English DT Meeting Abstract C1 USN,MED RES INST,BETHESDA,MD 20889. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 30 PY 1996 VL 10 IS 6 BP 606 EP 606 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA UK861 UT WOS:A1996UK86100836 ER PT J AU Rollwagen, FM Li, YY Pacheco, ND Zhu, XL Kang, YH AF Rollwagen, FM Li, YY Pacheco, ND Zhu, XL Kang, YH TI Orally administered IL-6 as prophylaxis for sepsis following hemorrhagic shock. SO FASEB JOURNAL LA English DT Meeting Abstract C1 USN,MED RES INST,BETHESDA,MD 20889. NR 0 TC 0 Z9 0 U1 0 U2 1 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 30 PY 1996 VL 10 IS 6 BP 1292 EP 1292 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA UK861 UT WOS:A1996UK86101521 ER PT J AU Baqar, S ElDin, AN Scott, DA Bourgeois, AL Kleinosky, MT Mourad, AS Murphy, JR AF Baqar, S ElDin, AN Scott, DA Bourgeois, AL Kleinosky, MT Mourad, AS Murphy, JR TI Influences of geographic origin and cryo-preservation of mononuclear cells on number of immunoglobulin secreting cells detected in human peripheral circulation. SO FASEB JOURNAL LA English DT Meeting Abstract C1 USN,MED RES INST,BETHESDA,MD 20889. UNIV ALEXANDRIA,FAC MED,ALEXANDRIA,EGYPT. US NAMRU 3,CAIRO,EGYPT. UNIV TEXAS,CTR INFECT DIS,HOUSTON,TX 77225. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 30 PY 1996 VL 10 IS 6 BP 2101 EP 2101 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA UK861 UT WOS:A1996UK86102331 ER PT J AU Perrin, PJ Davis, TA Smoot, DS Abe, R June, CH Lee, KP AF Perrin, PJ Davis, TA Smoot, DS Abe, R June, CH Lee, KP TI Distinct requirements of lymph node T cells for B7-1 (CD80) and B7-2 (CD86) costimulation in response to concanavalin A. SO FASEB JOURNAL LA English DT Meeting Abstract C1 USN,MED RES INST,BETHESDA,MD 20889. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 30 PY 1996 VL 10 IS 6 BP 2618 EP 2618 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA UK861 UT WOS:A1996UK86102846 ER PT J AU Palmer, L Saha, B Hodes, R Abe, R AF Palmer, L Saha, B Hodes, R Abe, R TI Immune-mediated responses against mouse mammary tumor virus (MMTV) in CD28-deficient mice. SO FASEB JOURNAL LA English DT Meeting Abstract C1 USN,RES INST,NATL NAVAL MED CTR,BETHESDA,MD 20892. NIA,NIH,BETHESDA,MD 20892. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD APR 30 PY 1996 VL 10 IS 6 BP 2639 EP 2639 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA UK861 UT WOS:A1996UK86102866 ER PT J AU Woods, TN Prinz, DK Rottman, GJ London, J Crane, PC Cebula, RP Hilsenrath, E Brueckner, GE Andrews, MD White, OR VanHoosier, ME Floyd, LE Herring, LC Knapp, BG Pankratz, CK Reiser, PA AF Woods, TN Prinz, DK Rottman, GJ London, J Crane, PC Cebula, RP Hilsenrath, E Brueckner, GE Andrews, MD White, OR VanHoosier, ME Floyd, LE Herring, LC Knapp, BG Pankratz, CK Reiser, PA TI Validation of the UARS solar ultraviolet irradiances: Comparison with the ATLAS 1 and 2 measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MONITOR-SUSIM-EXPERIMENT; INSTRUMENT; ATMOSPHERE; STANDARDS; BOARD; OZONE; NM AB The measurements of the solar ultraviolet spectral irradiance made by the two Upper Atmosphere Research Satellite (UARS) solar instruments, Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) and SOLar STellar Irradiance Comparison Experiment (SOLSTICE), are compared with same-day measurements by two solar instruments on the shuttle ATmospheric Laboratory for Applications and Science (ATLAS) missions, ATLAS SUSIM and Shuttle Solar Backscatter UltraViolet (SSBUV) experiment. These measurements from the four instruments agree to within the 2 sigma uncertainty of any one instrument, which is 5 to 10% for all wavelengths above 160 nm and for strong emission features below 160 nm. Additionally, the long-term relative accuracy of the two UARS data sets is better than the original 2% goal, especially at wavelengths greater than 160 nm. This level of agreement is credited to accurate preflight calibrations coupled with comprehensive inflight calibrations to track instrument degradation. Two solar irradiance spectra, 119 to 410 nm, are presented; the first combines observations from UARS SUSIM and UARS SOLSTICE taken on March 29, 1992, during the ATLAS 1 mission, and the second combines spectra for April 15, 1993, during the ATLAS 2 mission. The ATLAS 1 mission coincided with the initial decline from the maximum of solar cycle 22 when solar activity was relatively high. The ATLAS 2 mission occurred somewhat later during the declining phase of the solar cycle 22 when solar activity was more moderate. C1 USN, RES LAB, EO HULBURT CTR SPACE RES, WASHINGTON, DC 20375 USA. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. HUGHES STX CORP, LANHAM, MD 20706 USA. INTERFEROMETR INC, VIENNA, VA 22182 USA. UNIV COLORADO, DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI, BOULDER, CO 80309 USA. RP Woods, TN (reprint author), NATL CTR ATMOSPHER RES, HIGH ALTITUDE OBSERV, POB 3000, BOULDER, CO 80307 USA. NR 52 TC 250 Z9 251 U1 0 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 30 PY 1996 VL 101 IS D6 BP 9541 EP 9569 DI 10.1029/96JD00225 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ404 UT WOS:A1996UJ40400002 ER PT J AU Lahoz, WA Suttie, MR Froidevaux, L Harwood, RS Lau, CL Lungu, TA Peckham, GE Pumphrey, HC Read, WG Shippony, Z Suttie, RA Waters, JW Nedoluha, GE Oltmans, SJ Russell, JM Traub, WA AF Lahoz, WA Suttie, MR Froidevaux, L Harwood, RS Lau, CL Lungu, TA Peckham, GE Pumphrey, HC Read, WG Shippony, Z Suttie, RA Waters, JW Nedoluha, GE Oltmans, SJ Russell, JM Traub, WA TI Validation of UARS microwave limb sounder 183 GHz H2O measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MESOSPHERIC WATER-VAPOR; TEMPERATURE; VARIABILITY; ATMOSPHERE; RETRIEVAL; MIDDLE AB The Upper Atmosphere Research Satellite (UARS) microwave limb sounder (MLS) makes measurements of thermal emission at 183.3 GHz which are used to infer the concentration of water vapor over a pressure range of 46 - 0.2 hPa (similar to 20 to similar to 60 km). We provide a validation of MLS H2O by analyzing the integrity of the measurements, by providing an error characterization, and by comparison with data from other instruments. It is estimated that version 3 MLS H2O retrievals are accurate to within 20-25 % in the lower stratosphere and to within 8-13 % in the upper stratosphere and lower mesosphere, The precision of a single profile is estimated to be similar to 0.15 parts per million by volume (ppmv) in the midstratosphere and 0.2 ppmv in the lower and upper stratosphere, In the lower mesosphere the estimate of a single profile precision is 0.25-0.45 ppmv. During polar winter conditions, H2O retrievals at 46 hPa can have a substantial contribution from climatology. The vertical resolution of MLS H2O retrievals is similar to 5 km. C1 CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. UNIV READING, DEPT METEOROL, CGAM, READING RG6 2AU, BERKS, ENGLAND. HERIOT WATT UNIV, DEPT PHYS, EDINBURGH EH14 4AS, MIDLOTHIAN, SCOTLAND. USN, RES LAB, WASHINGTON, DC 20375 USA. NASA, LANGLEY RES CTR, HAMPTON, VA 23665 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. HARVARD SMITHSONIAN CTR ASTROPHYS, CAMBRIDGE, MA 02138 USA. RP Lahoz, WA (reprint author), UNIV EDINBURGH, DEPT METEOROL, EDINBURGH EH9 3JZ, MIDLOTHIAN, SCOTLAND. NR 28 TC 36 Z9 36 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 30 PY 1996 VL 101 IS D6 BP 10129 EP 10149 DI 10.1029/95JD01703 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ404 UT WOS:A1996UJ40400027 ER PT J AU Harries, JE Russell, JM Tuck, AF Gordley, LL Purcell, P Stone, K Bevilacqua, RM Gunson, M Nedoluha, G Traub, WA AF Harries, JE Russell, JM Tuck, AF Gordley, LL Purcell, P Stone, K Bevilacqua, RM Gunson, M Nedoluha, G Traub, WA TI Validation of measurements of water vapor from the halogen occultation experiment (HALOE) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MIDDLE ATMOSPHERE; STRATOSPHERE; AEROSOL AB The Halogen Occultation Experiment (HALOE) experiment is a solar occultation limb sounder which operates between 2.45 and 10.0 mu m to measure the composition of the mesosphere, stratosphere, and upper troposphere. It flies onboard the Upper Atmosphere Research Satellite (UARS) which was launched in September 1991. Measurements are made of the transmittance of the atmosphere in a number of spectral channels as the Sun rises or sets behind the limb of the atmosphere. One of the channels, at 6.60 mu m, is a broadband filter channel tuned to detect absorption in the nu(2) band of water vapor. This paper describes efforts to validate the absolute and relative uncertainties (accuracy and precision) of the measurements from this channel. The HALOE data have been compared with independent measurements, using a variety of observational techniques, from balloons, from the ground, and from other space missions, and with the results of a two-dimensional model. The results show that HALOE is providing global measurements throughout the stratosphere and mesosphere with an accuracy within +/-10% over most of this height range, and to within +/-30% at the boundaries, and to a precision in the lower stratosphere of a few percent. The H2O data are combined with HALOE measurements of CH4 in order to test the data in terms of conservation of total hydrogen, with most encouraging results. The observed systematic behavior and internal consistency of the HALOE data, coupled with these estimates of their accuracy, indicate that the data may be used for quantitative tests of our understanding of the physical and chemical processes which control the concentration of H2O in the middle atmosphere. C1 USN, RES LAB, WASHINGTON, DC 20375 USA. G&A TECH SOFTWARE, HAMPTON, VA 23666 USA. CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. NASA, LANGLEY RES CTR, DIV ATMOSPHER SCI, HAMPTON, VA 23861 USA. SMITHSONIAN ASTROPHYS OBSERV, CAMBRIDGE, MA 02138 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. RP Harries, JE (reprint author), UNIV LONDON IMPERIAL COLL SCI & TECHNOL, BLACKETT LAB, PRINCE CONSORT RD, LONDON SW7 2BZ, ENGLAND. RI Tuck, Adrian/F-6024-2011 OI Tuck, Adrian/0000-0002-2074-0538 NR 24 TC 135 Z9 136 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 30 PY 1996 VL 101 IS D6 BP 10205 EP 10216 DI 10.1029/95JD02933 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ404 UT WOS:A1996UJ40400032 ER PT J AU Vasudevan, AK Przystupa, MA Fricke, WG AF Vasudevan, AK Przystupa, MA Fricke, WG TI Effect of composition on crystallographic texture in hot-rolled Al-Li-Cu alloys SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE hot-rolling textures; anisotropy ID POLYCRYSTALLINE FCC METALS; ROLLING TEXTURES; PRECIPITATION STATE; RECRYSTALLIZATION; TEMPERATURE; DEFORMATION; MECHANISM AB The hot-rolling textures of ternary Al-Li-Cu alloys have been characterized to determine their effects on the yield strength anisotropy. The alloys used in the study had (Li/Cu) ratios varying from 0 to infinity and were hot-rolled in the 520-400 degrees C temperature range. All the alloys showed well developed beta-fibers, with a maximum intensity at Brass, and a weak background of alpha-fiber. The Brass components were very strong for the alloys with intermediate (Li/Cu) ratios that had relatively more T-1 precipitates in the microstructure compared with other alloys. In addition, all compositions showed a weak Cube or related Cube recrystallization texture components. The observed textures are attributed to the effects of constrained deformation during hot deformation. The texture results were used to predict the yield strength anisotropies in the alloys. The predictions were in agreement with the experimental results for the high (Li/Cu) alloys. However, in the low (Li/Cu) alloys, the discrepancies between the predicted and the measured yield strength anisotropies can be attributed to a modifying effect of the directional platelet precipitates on deformation. C1 UNIV CALIF LOS ANGELES,DEPT MAT SCI & ENGN,LOS ANGELES,CA 90024. ALCOA TECH CTR,ALCOA CTR,PA 15069. RP Vasudevan, AK (reprint author), OFF NAVAL RES,CODE 332,800 N QUINCY ST,ARLINGTON,VA 22217, USA. NR 32 TC 13 Z9 18 U1 3 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD APR 30 PY 1996 VL 208 IS 2 BP 172 EP 180 DI 10.1016/0921-5093(95)10064-4 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA UR453 UT WOS:A1996UR45300004 ER PT J AU Khleif, SN DeGregori, J Yee, CL Otterson, GA Kaye, FJ Nevins, JR Howley, PM AF Khleif, SN DeGregori, J Yee, CL Otterson, GA Kaye, FJ Nevins, JR Howley, PM TI Inhibition of cyclin D-CDK4/CDK6 activity is associated with an E2F-mediated induction of cyclin kinase inhibitor activity SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE human papillomaviruses; cervical cancer; E7 oncoprotein; retinoblastoma protein ID RETINOBLASTOMA GENE-PRODUCT; HUMAN PAPILLOMAVIRUS TYPE-16; CARCINOMA CELL-LINES; CERVICAL-CARCINOMA; DEPENDENT REGULATION; PROTEIN; PHOSPHORYLATION; EXPRESSION; TRANSCRIPTION; BINDING AB Alterations of various components of the cell cycle regulatory machinery that controls the progression of cells from a quiescent to a growing state contribute to the development of many human cancers. Such alterations include the deregulated expression of G(1) cyclins, the loss of function of activities such as those of protein p16(INK4a) that control G(1) cyclin-dependent kinase activity, and the loss of function of the retinoblastoma protein (RB),which is normally regulated by the G(1) cyclin-dependent kinases. Various studies have revealed an inverse relationship in the expression of p16(INK4a) protein and the presence of functional RB in many cell lines. In this study we show that p16(INK4a) is expressed in cervical cancer cell lines in which the RB gene, Rb, is not functional, either as a consequence of Rb mutation or expression of the human papillomavirus E7 protein. We also demonstrate that p16(INK4a) levels are increased in primary cells in which RB has been inactivated by DNA tumor virus proteins. Given the role of RB in controlling E2F transcription factor activity, we investigated the role of E2F in controlling p16(INK4a) expression. We found that E2F1 overexpression leads to an inhibition of cyclin D1-dependent kinase activity and induces the expression of a p16-related transcript. We conclude that the accumulation of G(1) cyclin-dependent kinase activity during normal G(1) progression leads to E2F accumulation through the inactivation of RB, and that this then leads to the induction of cyclin kinase inhibitor activity and a shutdown of G(1) kinase activity. C1 USN,NCI,MED ONCOL BRANCH,BETHESDA,MD 20889. UNIFORMED SERV UNIV HLTH SCI,BETHESDA,MD 20814. DUKE UNIV,MED CTR,HOWARD HUGHES MED INST,DEPT GENET,DURHAM,NC 27710. NCI,DERMATOL BRANCH,BETHESDA,MD 20892. HARVARD UNIV,SCH MED,DEPT PATHOL,BOSTON,MA 02115. RI kaye, frederic/E-2437-2011 NR 59 TC 232 Z9 241 U1 0 U2 5 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD APR 30 PY 1996 VL 93 IS 9 BP 4350 EP 4354 DI 10.1073/pnas.93.9.4350 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UK557 UT WOS:A1996UK55700114 PM 8633069 ER PT J AU Bacmeister, JT Eckermann, SD Newman, PA Lait, L Chan, KR Loewenstein, M Proffitt, MH Gary, BL AF Bacmeister, JT Eckermann, SD Newman, PA Lait, L Chan, KR Loewenstein, M Proffitt, MH Gary, BL TI Stratospheric horizontal wavenumber spectra of winds, potential temperature, and atmospheric tracers observed by high-altitude aircraft SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ANTARCTIC OZONE EXPERIMENT; WAVE NUMBER SPECTRA; GRAVITY-WAVES; PERTURBATION SPECTRA; BALLOON OBSERVATIONS; ENERGY-DISSIPATION; LIDAR OBSERVATIONS; MESOSCALE MOTIONS; FREQUENCY-SPECTRA; MIDDLE ATMOSPHERE AB Horizontal wavenumber power spectra of vertical and horizontal wind velocities, potential temperatures, and ozone and N2O mixing ratios, as measured in the mid-stratosphere during 73 ER-2 flights (altitude approximate to 20 km) are presented. The velocity and potential temperature spectra in the 100 to 1-km wavelength range deviate significantly from the uniform -5/3 power law expected for the inverse energy-cascade regime of two-dimensional turbulence and also for inertial-range, three-dimensional turbulence. Instead, steeper spectra approximately consistent with a -3 power law are observed at horizontal scales smaller than 3 km for all velocity components as well as potential temperature. Shallower spectra are observed at scales longer than 6 km. For horizontal velocity and potential temperature the spectral indices at longer scales are between -1.5 and -2.0. For vertical velocity the spectrum at longer scales becomes flat. It is argued that the observed velocity and potential temperature spectra are consistent with gravity waves. At smaller scales, the shapes are also superficially consistent with a Lumley-Shur-Weinstock buoyant subrange of turbulence and/or nonlinear gravity waves. Contemporaneous spectra of ozone and N2O mixing ratio in the 100 to 1-km wavelength range do conform to an approximately uniform -5/3 power law. It is argued that this may reflect interactions between gravity wave air-parcel displacements and laminar or filamentary structures in the trace gas mixing ratio field produced by enstrophy-cascading two-dimensional turbulence. C1 NASA, AMES RES CTR, MOFFETT FIELD, CA 94035 USA. COMPUTAT PHYS INC, FAIRFAX, VA 22031 USA. NASA, JET PROP LAB, PASADENA, CA 91109 USA. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. RP Bacmeister, JT (reprint author), USN, RES LAB, WASHINGTON, DC 20375 USA. RI Newman, Paul/D-6208-2012 OI Newman, Paul/0000-0003-1139-2508 NR 99 TC 103 Z9 104 U1 2 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD APR 27 PY 1996 VL 101 IS D5 BP 9441 EP 9470 DI 10.1029/95JD03835 PG 30 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UJ130 UT WOS:A1996UJ13000011 ER PT J AU Campbell, ML Metzger, JR AF Campbell, ML Metzger, JR TI Kinetic study of the reaction of Fe(a D-5(J)) with N2O from 398 to 620 K SO CHEMICAL PHYSICS LETTERS LA English DT Article ID EXOTHERMIC HOMOLOGOUS REACTIONS; TRANSITION-METAL ATOMS; ACTIVATION BARRIERS; GAS-PHASE; IRON ATOMS; OXIDATION; SERIES; NO; O2; TI(A3F) AB The gas phase reactivity of Fe(a(5)D(J)) with N2O in the temperature range 398-620 K is reported. Iron atoms were produced by the photodissociation of ferrocene and detected by laser-induced fluorescence. The reaction rates of the a D-5(J) states are very slow and temperature dependent. The bimolecular rate constant is described in Arrhenius form by (1.41 +/- 0.29) x 10(-10) exp(-44.4 +/- 1.0 kJ/mol/RT) cm(3) s(-1) where the uncertainties are +/- 2 sigma. The disappearance rates in the presence of N2O are independent of buffer gas identity (Ar or N-2) and total pressure. The removal rate constants for the a 5D(J) states are independent of J. RP Campbell, ML (reprint author), USN ACAD,DEPT CHEM,ANNAPOLIS,MD 21402, USA. NR 28 TC 29 Z9 29 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD APR 26 PY 1996 VL 253 IS 1-2 BP 158 EP 164 DI 10.1016/0009-2614(96)00202-3 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA UK635 UT WOS:A1996UK63500028 ER PT J AU Mera, AE Snow, AW AF Mera, AE Snow, AW TI Analysis of volatiles evolved during high-temperature treatment of thermally stable polymers .2. Polybutadiyne SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article AB Polybutadiyne samples were heated at 20 degrees C/min up to 1200 degrees C in a pyroprobe attached to a gas chromatograph/mass spectrometer (GC/MS). Analysis of the volatiles evolved during heating identified carbon dioxide (adsorbed on polymer surface), methane, ethylene, benzene, toluene, and traces of higher aromatics. Correlations have been made between sample temperature and evolution (onset, maximum, and end temperatures) of each of the five listed volatiles. Average polybutadiyne weight loss at 1200 degrees C was 14 +/- 2%. Two cure studies were performed in the pyroprobe, and it was shown that both weight loss and volatile evolution were affected. The results were consistent with a higher degree of polymer crosslinking as cure time and temperature increased. (C) 1996 John Wiley & Sons, Inc. RP Mera, AE (reprint author), USN,RES LAB,MAT CHEM BRANCH,CODE 6120,WASHINGTON,DC 20375, USA. NR 9 TC 2 Z9 2 U1 1 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD APR 25 PY 1996 VL 60 IS 4 BP 609 EP 616 DI 10.1002/(SICI)1097-4628(19960425)60:4<609::AID-APP15>3.0.CO;2-U PG 8 WC Polymer Science SC Polymer Science GA UB529 UT WOS:A1996UB52900015 ER PT J AU Diloreto, J AF Diloreto, J TI Critics naive about flying safety SO AVIATION WEEK & SPACE TECHNOLOGY LA English DT Letter RP Diloreto, J (reprint author), USN,BELLEVUE,WA, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MCGRAW HILL INC PI NEW YORK PA 1221 AVENUE OF THE AMERICAS, NEW YORK, NY 10020 SN 0005-2175 J9 AVIAT WEEK SPACE TEC JI Aviat. Week Space Technol. PD APR 22 PY 1996 VL 144 IS 17 BP 8 EP 8 PG 1 WC Engineering, Aerospace SC Engineering GA UG200 UT WOS:A1996UG20000001 ER PT J AU Coullard, CR Rais, A Rardin, RL Wagner, DK AF Coullard, CR Rais, A Rardin, RL Wagner, DK TI The dominant of the 2-connected-Steiner-subgraph polytope for W-4-free graphs SO DISCRETE APPLIED MATHEMATICS LA English DT Article ID CONNECTIVITY CONSTRAINTS; NETWORKS AB This paper presents a linear-inequality description of the dominant of the polytope of the 2-connected Steiner subgraphs of a given W-4-free graph. For the special case of 2-connected spanning subgraphs, a description of the polytope is given. The latter contains the Traveling-Salesman polytope for W-4-free graphs as a face. C1 OFF NAVAL RES, MATH SCI DIV, ARLINGTON, VA 22217 USA. NORTHWESTERN UNIV, DEPT IND ENGN & MANAGEMENT SCI, EVANSTON, IL 60208 USA. BALL STATE UNIV, DEPT COMP SCI, MUNCIE, IN 47306 USA. PURDUE UNIV, SCH IND ENGN, W LAFAYETTE, IN 47097 USA. RI Rais, Abdur/D-8847-2017 OI Rais, Abdur/0000-0003-1906-9684 NR 22 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-218X EI 1872-6771 J9 DISCRETE APPL MATH JI Discret Appl. Math. PD APR 22 PY 1996 VL 66 IS 1 BP 33 EP 43 DI 10.1016/0166-218X(94)00135-Z PG 11 WC Mathematics, Applied SC Mathematics GA UL437 UT WOS:A1996UL43700003 ER PT J AU Hartman, RC Webb, JR Marscher, AP Travis, JP Dermer, CD Aller, HD Aller, MF Balonek, TJ Bennett, K Bloom, SD Fujimoto, R Hermsen, W Hughes, P Jenkins, P Kii, T Kurfess, JD Makino, F Mattox, JR vonMontigny, C Ohashi, T Robson, I Ryan, J Sadun, A Schonfelder, V Smith, AG Terasranta, H Tornikoski, M Turner, MJL AF Hartman, RC Webb, JR Marscher, AP Travis, JP Dermer, CD Aller, HD Aller, MF Balonek, TJ Bennett, K Bloom, SD Fujimoto, R Hermsen, W Hughes, P Jenkins, P Kii, T Kurfess, JD Makino, F Mattox, JR vonMontigny, C Ohashi, T Robson, I Ryan, J Sadun, A Schonfelder, V Smith, AG Terasranta, H Tornikoski, M Turner, MJL TI Simultaneous multiwavelength spectrum and variability of 3C 279 from 10(9) to 10(24) Hz SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays, observations; infrared, galaxies; quasars, individual (3C 279); X-rays, galaxies ID ENERGY GAMMA-RADIATION; EXTRAGALACTIC RADIO-SOURCES; RELATIVISTIC JETS; X-RAY; MULTIFREQUENCY OBSERVATIONS; EGRET DETECTION; QUASAR 3C-279; MILLIMETER; TELESCOPE; EMISSION AB Data from a number of monitoring programs have been combined with data from the Compton Gamma Ray Observatory and the Ginga X-ray satellite to construct a spectrum covering nearly 15 decades in frequency during or near the time of the 3C 279 gamma-ray flare observed by EGRET in 1991 June. A much less complete spectrum is presented for 1991 October. Light curves from early 1991 to mid-1992 are presented for radio, millimeter, submillimeter, infrared, optical, and gamma-rays. Although the temporal coverage is incomplete, the only evidence for correlation in variability between the gamma-rays and lower frequencies is a flare in the optical R-band that peaks within similar to 1 day of the maximum in the gamma-ray light curve. The variability shows higher relative amplitude in gamma-rays than in the R band. We present spectral fits to the overall multi-wave band spectrum averaged over the 1991 June flare corresponding to two models: (i) synchrotron self-Compton (SSC) emission from a relativistic jet and (ii) inverse Compton scattering of seed photons originating external to the jet (ECS) by the synchrotron-emitting relativistic electrons in the jet. Either model can fit the observed spectra satisfactorily. The higher amplitude of the gamma-ray variations is as predicted by the SSC model and can be accommodated within the ECS model if the flare is caused by a temporary change in the bulk Lorentz factor of the gamma-ray-emitting plasma. C1 FLORIDA INT UNIV, DEPT PHYS, MIAMI, FL 33199 USA. BOSTON UNIV, DEPT ASTRON, BOSTON, MA 02215 USA. USN, RES LAB, WASHINGTON, DC 20375 USA. UNIV MICHIGAN, DEPT ASTRON, ANN ARBOR, MI 48109 USA. COLGATE UNIV, DEPT PHYS & ASTRON, HAMILTON, NY 13346 USA. EUROPEAN SPACE AGCY, ESTEC, DIV ASTROPHYS, 2200 AG NOORDWIJK, NETHERLANDS. TECHNION ISRAEL INST TECHNOL, ASHER SPACE RES INST, HAIFA, ISRAEL. INST SPACE & ASTRONAUT SCI, SAGAMIHARA, KANAGAWA 229, JAPAN. SRON, 3584 CA UTRECHT, NETHERLANDS. UNIV MARYLAND, DEPT ASTRON, COLLEGE PK, MD 20742 USA. TOKYO METROPOLITAN UNIV, DEPT PHYS, HACHIOJI, TOKYO 19203, JAPAN. JCMT, HILO, HI 96720 USA. UNIV NEW HAMPSHIRE, INST EARTH OCEANS & SPACE, DURHAM, NH 03824 USA. AGNES SCOTT COLL, BRADLEY OBSERV, DECATUR, GA 30030 USA. MAX PLANCK INST EXTRATERR PHYS, W-8046 GARCHING, GERMANY. UNIV FLORIDA, DEPT ASTRON, GAINESVILLE, FL 32611 USA. METSAHOVI RADIO RES STN, SF-02540 KYLMALA, FINLAND. UNIV LEICESTER, DEPT PHYS & ASTRON, LEICESTER LE1 7RH, LEICS, ENGLAND. RP Hartman, RC (reprint author), NASA, GODDARD SPACE FLIGHT CTR, CODE 661, GREENBELT, MD 20771 USA. NR 69 TC 108 Z9 110 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 20 PY 1996 VL 461 IS 2 BP 698 EP 712 DI 10.1086/177095 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UE570 UT WOS:A1996UE57000019 ER PT J AU Sturner, SJ Dermer, CD AF Sturner, SJ Dermer, CD TI Statistical analysis of gamma-ray properties of rotation-powered pulsars SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays, observations; gamma rays, theory; pulsars, general; stars, neutron; stars, statistics ID RAPIDLY SPINNING PULSARS; SINGLE RADIO PULSARS; GALACTIC PLANE; POLAR CAPS; ENERGETIC RADIATION; PERIOD; MAGNETOSPHERES; EMISSION; GAPS; CRAB AB Monte Carlo methods are used to simulate the properties of the Galactic population of rotation-powered pulsars in a model where the gamma rays are produced by energetic electrons that Compton-scatter photons near the pulsar polar cap. We use results of radio pulsar statistical studies to assign the initial magnetic field, spatial, and velocity distributions of neutron stars at birth. Gamma-ray and radio fluxes are calculated for an observer at Earth and are used to determine the expected number of detectable gamma-ray pulsars. The results are compared with the observed properties of the seven known gamma-ray pulsars. We investigate models where the polar-cap angle is 1, 2, and 4 times larger than the nominal polar-cap angle determined by the open field lines of an aligned dipole magnetic field and where the initial rotation period is 20 or 30 ms. We find that the distance, period, age, magnetic field, and gamma-ray flux distributions of the observed gamma-ray pulsars are best represented by a model where the initial pulse period is 30 ms and the polar cap angle is 4 times larger than the nominal angle. For this model, we predict greater than or similar to 2-4 radio-quiet pulsars that emit gamma rays at flux levels of the known gamma-ray pulsars. The emission of unresolved gamma-ray pulsars is found to contribute to the diffuse Galactic gamma-ray continuum at the 5%-10% level. RP Sturner, SJ (reprint author), USN, RES LAB, EO HULBURT CTR SPACE RES, CODE 7653, WASHINGTON, DC 20375 USA. NR 59 TC 38 Z9 38 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 20 PY 1996 VL 461 IS 2 BP 872 EP 883 DI 10.1086/177108 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UE570 UT WOS:A1996UE57000032 ER PT J AU Bitterwolf, TE Leonard, MB Horine, PA Shade, JE Rheingold, AL Staley, DJ Yap, GPA AF Bitterwolf, TE Leonard, MB Horine, PA Shade, JE Rheingold, AL Staley, DJ Yap, GPA TI Synthesis of mono- and bimetallic ruthenium carbonyl compounds from ring-coupled bis(cyclopentadienyl thallium) reagents. The molecular structures of [Ru(CO)(2)][Ru(CO)(2)Cl][eta(5),eta(5):eta(1)-C5H4(CH2)(2)CC5H3], Ru-2(CO)(4)[eta(5),eta(5)-C5H4(CH3)(2)SiC5H4] and [Ru(CO)(2)Br][Ru(CO)(2)Cl][eta(5),eta(5)-C5H4C2H4C5H4] SO JOURNAL OF ORGANOMETALLIC CHEMISTRY LA English DT Article DE ruthenium; thallium; silicon; bimetallic; metal carbonyl; ring-coupled ID ANSA-METALLOCENE DERIVATIVES; COMPLEXES; REACTIVITY; LIGANDS AB Reaction of ring-coupled bis(cyclopentadienylthallium) compounds of the general form Tl-2[C(5)H(4)LC(5)H(4)], where L = CH2-, (CH3)(2)C-, (CH3)(2)Si-, C2H4-, with [Cl2Ru(CO)(3)](2) was found to form a family of mono- and bimetallic complexes including compounds of the form: Ru-2(CO)(4)(eta(5),eta(5)-C(5)H(4)LC(5)H(4)), Ru(CO)(2)(eta(5),eta(5.1):-C(5)H(4)LC(5)H(4)) [Ru(CO)(2)][Ru(CO)(2)Cl](eta(5),eta(5):eta(1)-C(5)H(4)LC(5)H(3)), and [Ru(CO)(2)Cl](2)(eta(5),eta(5)-C(5)H(4)LC(5)H(4)). These compounds have been completely characterized by IR, H-1 and C-13 NMR, mass spectrometry and elemental analysis. The molecular structures of several compounds in this series have been determined: [Ru(CO)(2)][Ru(CO)(2)Cl][eta(5),eta(5):eta(1)-C5H4(CH2)(2)CC5H3]: triclinic, P (1) over bar, a = 7.812(3) Angstrom, b = 9.004(2) Angstrom, c = 12.773(5) Angstrom, alpha = 84.33(3)degrees, beta = 75.26(3)degrees, gamma = 80.93(3)degrees, V = 857.3(6) Angstrom(3) Z = 2, R(F) = 3.52%. Ru-2(CO)(4)[eta(5),eta(5)-C5H4(CH3)(2)SiC5H4]; monoclinic, P2(1)/n, a = 11.036(2) Angstrom, b = 13.660(2) Angstrom, c = 11.621(2) Angstrom, beta = 105.83(2)degrees, V = 1688.6(5) Angstrom(3), Z = 4, R(F) = 2.68%; [Ru(CO)(2)Cl][Ru(CO)(2))Br](eta(5),eta(5)-C5H4C2H4C5H4):, monoclinic, C2/c, a = 25.237(3) Angstrom, b = 6.049(1) Angstrom, c = 12.646(2) Angstrom, beta = 109.73(1)degrees, V = 1817(2) Angstrom(3), Z = 4, R(F) = 4.37%. C1 USN ACAD,DEPT CHEM,ANNAPOLIS,MD 21402. UNIV DELAWARE,DEPT CHEM & BIOCHEM,NEWARK,DE 19716. RP Bitterwolf, TE (reprint author), UNIV IDAHO,DEPT CHEM,MOSCOW,ID 83844, USA. NR 15 TC 36 Z9 36 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-328X J9 J ORGANOMET CHEM JI J. Organomet. Chem. PD APR 19 PY 1996 VL 512 IS 1-2 BP 11 EP 20 DI 10.1016/0022-328X(95)06007-J PG 10 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA UN568 UT WOS:A1996UN56800003 ER PT J AU Coyer, JA CabelloPasini, A Swift, H Alberte, RS AF Coyer, JA CabelloPasini, A Swift, H Alberte, RS TI N-2 fixation in marine heterotrophic bacteria: Dynamics of environmental and molecular regulation SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE dinitrogenase reductase; nifHDK operon; nitrogenase; in situ hybridization; Vibrio natriegens ID NITROGEN-FIXATION; TRICHODESMIUM-THIEBAUTII; VIBRIO; GENES; RNA; SEAWATER; GENETICS; GROWTH; CELLS AB Molecular and immunological techniques were used to examine N-2 fixation in a ubiquitous heterotrophic marine bacterium, the facultative anaerobic Vibrio natriegens. When batch cultures were shifted from aerobic N-replete to anaerobic N-deplete conditions, transcriptional and posttranslational regulation of N-2 fixation was observed, Levels of nifHDK mRNA encoding the nitrogenase enzyme mere highest at 140 min postshift and undetectable between 6 and 9 h later, Immunologically determined levels of nitrogenase enzyme (Fe protein) were highest between 6 and 15 h postshift, and nitrogenase activity peaked between 6 and 9 h postshift, declining by a factor of 2 after 12-15 h, Unlike their regulation in cyanobacteria, Fe protein and nitrogenase activity were present when nifHDK mRNA was absent in V. natriegens, indicating that nitrogenase is stored and stable under anaerobic conditions, Both nifHDK mRNA and Fe protein disappeared within 40 min after cultures were shifted from N2-fixing conditions (anaerobic, N-deplete) to non-N-2-fixing conditions (aerobic, N-enriched) but reappeared when shifted to conditions favoring N-2 fixation, Thus, unlike other N-2-fixing heterotrophic bacteria, nitrogenase must be resynthesized after aerobic exposure in V. natriegens. Immunological detection based on immunoblot (Western) analysis and immunogold labeling correlated positively with nitrogenase activity; no localization of nitrogenase was observed, Because V. natriegens continues to fix N-2 for many hours after anaerobic induction, this species may play an important role in providing ''new'' nitrogen in marine ecosystems. C1 UNIV CALIF LOS ANGELES, DEPT BIOL, LOS ANGELES, CA 90024 USA. SUNY STONY BROOK, INST MARINE SCI, STONY BROOK, NY 11794 USA. UNIV CHICAGO, DEPT MOLEC GENET & CELL BIOL, CHICAGO, IL 60637 USA. OFF NAVAL RES, BIOL SCI & TECHNOL PROGRAM, ARLINGTON, VA 22217 USA. RI Coyer, James/B-3295-2010 NR 43 TC 14 Z9 14 U1 3 U2 9 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD APR 16 PY 1996 VL 93 IS 8 BP 3575 EP 3580 DI 10.1073/pnas.93.8.3575 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UF740 UT WOS:A1996UF74000079 PM 11607653 ER PT J AU Deschamps, JR George, C Gilardi, RD Gagnon, JL Zajac, WW AF Deschamps, JR George, C Gilardi, RD Gagnon, JL Zajac, WW TI cis-1,5-dimethyl-2,4-dinitro-2,4-diazabicyclo[3.2.0]heptan-3-one and cis-1,5-dimethyl-2,4-dinitro-2,4-diazabicyclo[3.1.0]hexan-3-one SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article AB The title compounds, C7H10N4O5, (I), and C6H8N4O5, (II), each consist of a five-membered ring fused to a smaller ring. In compound (I), the C-C bridging bond distance [1.571 (4) Angstrom] is longer than the expected distance of 1.54 Angstrom for a C-C bond in a cyclobutane ring, In compound (II), however, the corresponding C-C bridging bond distance [1.507 (5) Angstrom] is consistent with the expected bond length (1,51 Angstrom) in a cyclopropane ring. The increase in the C-C bridge distance in compound (I) is most likely due to steric effects resulting from the additional methyl substituents. C1 VILLANOVA UNIV,DEPT CHEM,VILLANOVA,PA 19085. RP Deschamps, JR (reprint author), USN,RES LAB,STRUCT MATTER LAB,WASHINGTON,DC 20375, USA. OI Deschamps, Jeffrey/0000-0001-5845-0010 NR 6 TC 4 Z9 4 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD APR 15 PY 1996 VL 52 BP 993 EP 995 DI 10.1107/S010827019501393X PN 4 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA UK550 UT WOS:A1996UK55000093 ER PT J AU Shahgholi, M Ross, MM Callahan, JH Smucker, RA AF Shahgholi, M Ross, MM Callahan, JH Smucker, RA TI Electrospray mass spectrometric detection of chitobiose in enzyme hydrolysates of marine phytoplankton SO ANALYTICAL CHEMISTRY LA English DT Article ID ANION-EXCHANGE CHROMATOGRAPHY; PERFORMANCE LIQUID-CHROMATOGRAPHY; PULSED AMPEROMETRIC DETECTION; GRAPHITIZED CARBON COLUMN; OLIGOSACCHARIDES; IONIZATION; INTERFACE; SUGARS AB The presence of chitin in algae was determined by mass spectrometric detection of its enzymatic hydrolysis end product, chitobiose. Electrospray mass spectrometry (ES-MS) was used for detection of chitobiose in the enzyme hydrolysate because of its capability to detect underivatized amino sugar oligomers. This strategy affords simplified sample preparation and reduced processing time. Despite the remarkable success in the analysis of purified sugars, ES mass spectrometric detection of sugars in complex matrices remains a challenging task and generally requires sample cleanup. This work demonstrates the use of ES-MS with both off-line and on-line sample cleanup for the detection of chitobiose generated by the enzymatic hydrolysis of chitin. The porous graphitic carbon (PGC) packing material used in the on-line method has been used for chromatographic separation of sugars and is particularly suitable for this assay because ES-compatible solvents such as water and acetonitrile can be used for analyte elution. The effectiveness of microscale liquid chromatography ES-MS with PGC was demonstrated for a suite of sugars. C1 USN, RES LAB, DIV CHEM, WASHINGTON, DC 20375 USA. SMITHSONIAN INST, SMITHSONIAN ENVIRONM RES CTR, EDGEWATER, MD 21037 USA. NR 52 TC 7 Z9 7 U1 2 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 EI 1520-6882 J9 ANAL CHEM JI Anal. Chem. PD APR 15 PY 1996 VL 68 IS 8 BP 1335 EP 1341 DI 10.1021/ac951240d PG 7 WC Chemistry, Analytical SC Chemistry GA UE566 UT WOS:A1996UE56600009 ER PT J AU Dunlap, BI AF Dunlap, BI TI Accurate density functional calculations on large systems SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article; Proceedings Paper CT International Workshop on Electronic Structure Methods for Truly Large Systems - Moving the Frontiers in Quantum Chemistry CY AUG 01-07, 1994 CL BRAUNLAGE, GERMANY ID TOTAL-ENERGY; BASIS-SETS; ALPHA; FULLERENES; MOLECULES; CARBON; C-60; CLUSTERS; EXCHANGE; SYMMETRY AB The theoretical underpinnings of the linear combination of Gaussian-type orbitals (LCGTO) calculations of the density functional (DF) energy of molecules and clusters are described. The generating function for three-center integrals of arbitrary angular momenta is given in the solid-spherical-harmonic basis. Variational fitting is described and its accuracy tested. The LCGTO-DF method is used to address questions related to the problem of how it is that the methods of cluster science, i.e., high-energy beams or currents, can be used to make C-60 in bulk quantities. In particular, it is shown that C-60 is neither especially stable nor is it the only large, stable, perfectly round, approximately sp(2) carbon molecule. (C) 1996 John Wiley & Sons, Inc. RP Dunlap, BI (reprint author), USN,RES LAB,THEORET CHEM SECT,CODE 6179,WASHINGTON,DC 20375, USA. OI Dunlap, Brett/0000-0003-1356-6559 NR 58 TC 11 Z9 11 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0020-7608 J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD APR 15 PY 1996 VL 58 IS 2 BP 123 EP 132 DI 10.1002/(SICI)1097-461X(1996)58:2<123::AID-QUA1>3.0.CO;2-# PG 10 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA UB736 UT WOS:A1996UB73600002 ER PT J AU Nolas, GS Slack, GA Morelli, DT Tritt, TM Ehrlich, AC AF Nolas, GS Slack, GA Morelli, DT Tritt, TM Ehrlich, AC TI The effect of rare-earth filling on the lattice thermal conductivity of skutterudites SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LAFE4P12 STRUCTURE; SINGLE-CRYSTALS; TEMPERATURE AB Polycrystalline samples of Ir4LaGe3Sb9,Ir4NdGe3Sb9, and Ir4SmGe3Sb9 have been made by hot isostatic pressing of powders. The lattice thermal conductivity of these filled skutterudites is markedly smaller than that of IrSb3; thus, void filling shows promise as a method for improving the thermoelectric properties of these materials. We present the lattice thermal conductivity of these filled skutterudites in an effort to quantify the impact of void filling in this structure. It is believed that the atoms ''rattle'' in the voids of the structure and therefore interact with a broad spectrum of lattice phonons, reducing their mean free paths substantially below that in the ''unfilled'' skutterudites. An additional phonon scattering mechanism is caused by phonon-stimulated transitions between the low-lying energy levels of the 4f electron configurations in the case of Nd3+ and Sm3+. Magnetic susceptibility and Hall-effect measurements are also presented. (C) 1996 American Institute of Physics. C1 GM CORP,CTR RES & DEV,DEPT PHYS,WARREN,MI 48090. USN,RES LAB,MAT PHYS BRANCH,WASHINGTON,DC 20375. RP Nolas, GS (reprint author), RENSSELAER POLYTECH INST,DEPT PHYS,TROY,NY 12180, USA. NR 57 TC 272 Z9 283 U1 6 U2 51 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4002 EP 4008 DI 10.1063/1.361828 PN 1 PG 7 WC Physics, Applied SC Physics GA UG876 UT WOS:A1996UG87600029 ER PT J AU Swain, PK Misra, D Thompson, PE AF Swain, PK Misra, D Thompson, PE TI Effect of dry etching and subsequent annealing of Si/SiGe/Si heterostructure SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID STRAINED-LAYER HETEROSTRUCTURES AB Exposure to dry etching can deleteriously affect strained SiGe films by initiation of misfit strain discontinuity in the film as well as at the interface. In this paper annealing behavior of defects generated as a consequence of dry etching of Si/SiGe/Si heterostructure metal-oxide-semiconductor capacitors have been reported. Some samples were wet etched for comparison. Samples were annealed at four different temperatures after being etched, namely, 650, 700, 750, and 800 degrees C. Results of the investigations using deep-level transient spectroscopy reveal defect levels at 0.62, 0.57, 0.56, and 0.44 eV for the dry-etched samples and at 0.31, 0.43, 0.56, and 0.44 eV for the wet-etched samples annealed at the aforetold temperatures. The results could be explained on the basis of appearance of point defects condensing into dislocation loops which eventually shrink and disappear as the annealing temperature is increased. The estimated size of the dislocation loops agrees quite well with the experimentally measured values obtained for identically processed samples. (C) 1996 American Institute of Physics. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Swain, PK (reprint author), NEW JERSEY INST TECHNOL,DEPT ELECT & COMP ENGN,NEWARK,NJ 07102, USA. NR 19 TC 9 Z9 9 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4402 EP 4406 DI 10.1063/1.361748 PN 1 PG 5 WC Physics, Applied SC Physics GA UG876 UT WOS:A1996UG87600087 ER PT J AU Nordstrom, L Singh, DJ AF Nordstrom, L Singh, DJ TI Calculated spacer-layer Friedel oscillations in Co/Cu(001) SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB The induced complete position-dependent magnetization density of the copper spacer layer is calculated for Co/Cu(001), as modeled by a Co/Cu-o/Co slab. This density is then analyzed in terms of Friedel oscillations. It is found that the variation of the density is well described by two periods, 1.2 and 1.6 monolayers, which are the nonaliased versions of the RKKY periods found in the interlayer coupling. The induced Cu magnetization is not well described in terms of local Cu moments, arising from local exchange interactions, but rather has significant free electron character, in the way that it is mainly induced by magnetic interface scattering. (C) 1996 American Institute of Physics. C1 USN,RES LAB,COMPLEX SYST THEORY BRANCH,WASHINGTON,DC 20375. RP Nordstrom, L (reprint author), GEORGE MASON UNIV,INST COMPUTAT SCI & INFORMAT,FAIRFAX,VA 22030, USA. RI Singh, David/I-2416-2012 NR 8 TC 5 Z9 5 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4515 EP 4517 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700008 ER PT J AU Krebs, JJ Prinz, GA Filipkowski, ME Gutierrez, CJ AF Krebs, JJ Prinz, GA Filipkowski, ME Gutierrez, CJ TI Interlayer thickness dependence of the strong 90 degrees coupling in epitaxial CoFe/Mn/CoFe trilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID FE AB Trilayers of CoFe/Mn/CoFe(001) have been prepared by molecular beam epitaxy and their magnetic properties measured by magnetometry and ferromagnetic resonance. Very strong near-90 degrees coupling between the CoFe layers, with no evidence for 180 degrees coupling, was found in all but the thickest Mn-Iayer samples. The coupling energy has the form suggested recently for the case when the interlayer itself is antiferromagnetic. An analysis of the ferromagnetic resonance data indicates that the magnitude of the coupling oscillates with the Mn thickness. (C) 1996 American Institute of Physics. C1 UNIV ARKANSAS,DEPT PHYS,FAYETTEVILLE,AR 72701. SW TEXAS STATE UNIV,DEPT PHYS,SAN MARCOS,TX 78666. RP Krebs, JJ (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 15 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4525 EP 4527 DI 10.1063/1.362437 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700011 ER PT J AU Byers, JM AF Byers, JM TI The effect of disorder and fluctuations on the magnetotransport of a double-exchange ferromagnet SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 USN,RES LAB,WASHINGTON,DC 20375. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4553 EP 4553 DI 10.1063/1.361721 PN 2A PG 1 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700024 ER PT J AU Park, JH Chen, CT Cheong, SW Bao, W Meigs, G Chakarian, V Idzerda, YU AF Park, JH Chen, CT Cheong, SW Bao, W Meigs, G Chakarian, V Idzerda, YU TI Electron spectroscopic studies of colossal magnetoresistance material La1-xCaxMnO3 SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID MAGNETIC-CIRCULAR-DICHROISM; FILMS AB High resolution photoemission measurements have been performed for the ferromagnetic transition Of La0.67Ca0.33MnO3 and for the order-disorder transition of La0.4Ca0.6MnO3. The band gap collapsed below the Curie temperature and the density of states at the Fermi level increases with cooling. Upon cooling through the order-disorder transition temperatures, T-CO, the band gap increases by similar to 50 meV. This change in the gap is consistent with the change in the activation energy above and below T-CO estimated from conductivity data. We have also performed soft x-ray magnetic circular dichroism measurements at Mn L(2,3) edges for ferromagnetic La0.6Ca0.33MnO3 and La0.8Ca0.2MnO3. (C) 1996 American Institute of Physics. C1 USN,RES LAB,WASHINGTON,DC 20375. JOHNS HOPKINS UNIV,DEPT PHYS,BALTIMORE,MD 21218. RP Park, JH (reprint author), AT&T BELL LABS,MURRAY HILL,NJ 07974, USA. RI Bao, Wei/E-9988-2011 OI Bao, Wei/0000-0002-2105-461X NR 20 TC 18 Z9 18 U1 2 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4558 EP 4560 DI 10.1063/1.361724 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700028 ER PT J AU Harris, VG Koon, NC Williams, CM Zhang, Q Abe, M AF Harris, VG Koon, NC Williams, CM Zhang, Q Abe, M TI Cation distribution in NiZn-ferrite films determined using x-ray absorption fine structure SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB We have applied extended x-ray absorption fine structure (EXAFS) spectroscopy to study the cation distribution in a series of spin-sprayed NiZn-ferrite films, Ni0.15ZnyFe2.85-yO4(y=0.16, 0.23, 0.40, 0.60). The Ni, Zn, and Fe EXAFS were collected from each sample and analyzed to Fourier transforms. Samples of Ni-ferrite, Zn-ferrite, and magnetite were similarly studied as empirical standards. These standards, together with EXAFS data generated from the theoretical EXAFS FEFF codes, allowed the correlation of features in the Fourier transforms with specific lattice sites in the spinel unit cell. We find that the Ni ions reside mostly on the octahedral (B) sites whereas the Zn ions are predominantly on the tetrahedral (A) sites. The Fe ions reside on both A and B sites in a ratio determined by the ratio of Zn/Fe. The addition of Zn displaces a larger fraction of Fe cations onto the B sites serving to increase the net magnetization. The fraction of A site Ni ions is measured to increase peaking at approximate to 25% for y=0.6. At higher Zn concentrations (y greater than or equal to 0.5) the lattice experiences local distortions around the Zn sites causing a decrease in the superexchange resulting in a decrease in the net magnetization. (C) 1996 American Institute of Physics. C1 MORGAN STATE UNIV,BALTIMORE,MD 21339. TOKYO INST TECHNOL,MEGURO KU,OKAYAMA,TOKYO 152,JAPAN. RP Harris, VG (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Harris, Vincent/A-8337-2009 NR 11 TC 16 Z9 17 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4561 EP 4563 DI 10.1063/1.361725 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700029 ER PT J AU Singh, DJ AF Singh, DJ TI Electronic and magnetic properties of the 4d itinerant ferromagnet SrRuO3 SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID THIN-FILMS AB Density functional calculations are used to elucidate the electronic and magnetic structure of SrRuO3. Itinerant ferromagnetic behavior is found both in the cubic perovskite and the actual orthorhombic structure. The calculated moment is 1.59 mu(B). Unusually strong hybridization is evident in both the electronic structure and magnetism. The Fermi velocities indicate significant spin differentiation of the transport properties. RP Singh, DJ (reprint author), USN,RES LAB,COMPLEX SYST THEORY BRANCH,WASHINGTON,DC 20375, USA. RI Singh, David/I-2416-2012 NR 23 TC 136 Z9 137 U1 2 U2 39 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4818 EP 4820 DI 10.1063/1.361618 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700124 ER PT J AU Snyder, JE Harris, VG Das, BN Koon, NC Sui, X Kryder, MH AF Snyder, JE Harris, VG Das, BN Koon, NC Sui, X Kryder, MH TI Determination of local order in the amorphous precursor to Ba-hexaferrite thin-film recording media SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB Ba-hexaferrite thin films for recording media applications are often fabricated by a two-step process: sputter deposition of an amorphous precursor, followed by annealing to crystallize the BaFe12O19 phase. The magnetic anisotropy of the crystalline films can be either in-plane or perpendicular, depending on the sputtering process used in the first step. However, conventional structural characterization techniques have not been able to distinguish between different as-sputtered films. Using polarization-dependent extended x-ray absorption fine structure (PD-EXAFS), we have observed anisotropic local structure around both Ba and Fe atoms in the amorphous precursor films. Comparison of the results suggests that the amorphous films consist of networks of Fe atoms surrounded by their O nearest neighbors, with Ba atoms fitting into in-between spaces as network modifiers (there might also be some minor Fe network modifying contribution). The local structural anisotropy of the amorphous films appears to determine the orientation of the fast-growing basal plane directions during annealing, and thus the directions of the c axes and the magnetic anisotropy. (C) 1996 American Institute of Physics. C1 SEAGATE TECHNOL,BLOOMINGTON,MN 55435. CARNEGIE MELLON UNIV,CTR DATA STORAGE SYST,PITTSBURGH,PA 15213. RP Snyder, JE (reprint author), USN,RES LAB,CODE 6342,WASHINGTON,DC 20375, USA. RI Harris, Vincent/A-8337-2009 NR 9 TC 7 Z9 7 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 4890 EP 4892 DI 10.1063/1.361641 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700150 ER PT J AU Kneedler, E Thibado, PM Jonker, BT Bennett, BR Whitman, LJ Shanabrook, BV Krebs, JJ AF Kneedler, E Thibado, PM Jonker, BT Bennett, BR Whitman, LJ Shanabrook, BV Krebs, JJ TI Fe adsorption and film growth on GaAs(001) (2x4)-As SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 USN,RES LAB,WASHINGTON,DC 20375. RI Bennett, Brian/A-8850-2008; Whitman, Lloyd/G-9320-2011 OI Bennett, Brian/0000-0002-2437-4213; Whitman, Lloyd/0000-0002-3117-1174 NR 0 TC 3 Z9 4 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5125 EP 5125 DI 10.1063/1.361528 PN 2A PG 1 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700244 ER PT J AU Park, K SalamancaRiba, L Jonker, BT AF Park, K SalamancaRiba, L Jonker, BT TI Microstructural properties of (ZnSe/FeSe) and (ZnSe/MnSe) diluted magnetic semiconductor superlattices SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 UNIV MARYLAND,DEPT MAT & NUCL ENGN,COLLEGE PK,MD 20742. USN,RES LAB,WASHINGTON,DC 20375. RI Salamanca-Riba, Lourdes/B-3785-2009 OI Salamanca-Riba, Lourdes/0000-0001-8155-6403 NR 2 TC 2 Z9 2 U1 2 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5195 EP 5195 DI 10.1063/1.361337 PN 2A PG 1 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700271 ER PT J AU OBarr, R Lederman, M Schultz, S Xu, WH Scherer, A Tonucci, RJ AF OBarr, R Lederman, M Schultz, S Xu, WH Scherer, A Tonucci, RJ TI Preparation and quantitative magnetic studies of single-domain nickel cylinders SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB For a complete experimental and theoretical explanation of the magnetic processes in an interacting collection of submicron magnetic particles, a fundamental understanding of the magnetic properties of individual single-domain particles must first be achieved. We have prepared elongated Ni columns ranging in diameter from 0.15 to 1.0 mu m by electroplating into specially prepared Al2O3 and glass channeled pore membranes. We have also prepared controlled arrays of Ni columns using e-beam lithography, subsequently electroplating into the written patterns. Using transmission electron microscopy, we have characterized the shape, size, morphology, and crystal structure of the columns. Magnetic force microscopy has been used to determine the switching field H-s versus the applied field angle of the columns. Although the switching field data can be fit to the functional form for nucleation by curling in an infinite cylinder, the observed weak dependence of H-s on column diameter is inconsistent with that expected for curling, particularly for columns of diameter >0.3 mu m. (C) 1996 American Institute of Physics. C1 UNIV CALIF SAN DIEGO, CTR MAGNET RECORDING RES, LA JOLLA, CA 92093 USA. CALTECH, DEPT ELECT ENGN, PASADENA, CA 91125 USA. USN, RES LABS, DIV OPT SCI, WASHINGTON, DC 20375 USA. RP OBarr, R (reprint author), UNIV CALIF SAN DIEGO, DEPT PHYS, 9500 GILMAN DR, LA JOLLA, CA 92093 USA. NR 14 TC 56 Z9 56 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5303 EP 5305 DI 10.1063/1.361359 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700310 ER PT J AU Kemner, KM Harris, VG Chakarian, V Idzerda, YU Elam, WT Kao, CC Feng, YC Laughlin, DE Woicik, JC AF Kemner, KM Harris, VG Chakarian, V Idzerda, YU Elam, WT Kao, CC Feng, YC Laughlin, DE Woicik, JC TI The role of Ta and Pt in segregation within Co-Cr-Ta and Co-Cr-Pt thin film magnetic recording media SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID RAY CIRCULAR-DICHROISM AB Polarization dependent extended x-ray absorption fine structure (PD-EXAFS) and magnetic circular dichroism (MCD) measurements of CoCrTa and CoCrPt films, sputter deposited at varying substrate temperatures, were performed to investigate the average local structure and chemistry about the Ta, Pt, and Co atoms and the average magnetic moment of the Co and Cr atoms within these films. Results from the MCD measurements indicate the average net magnetic moment of the Cr atoms is opposite in direction and five percent in amplitude relative to the Co moments. Inspection of the Fourier transforms of the XAFS data from these samples shows an increase in structural disorder around the Ta and Pt atoms with increasing substrate deposition temperature. A further comparison between the Ta and Pt edge EXAFS results show that the temperature-dependent increase in structural disorder is greater around the Ta atoms in the CoCrTa system than it is around the Pt atoms in the CoCrPt system. (C) 1996 American Institute of Physics. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. CARNEGIE MELLON UNIV,DEPT MAT SCI & ENGN,PITTSBURGH,PA 15213. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Kemner, KM (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Harris, Vincent/A-8337-2009 NR 12 TC 7 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5345 EP 5347 DI 10.1063/1.361372 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700324 ER PT J AU Mar, DJ Carroll, TL Pecora, LM Heagy, JF Rachford, FJ AF Mar, DJ Carroll, TL Pecora, LM Heagy, JF Rachford, FJ TI Driven spin-wave dynamics in yttrium-iron-garnet films SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 USN,RES LAB,WASHINGTON,DC 20375. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5377 EP 5377 DI 10.1063/1.362308 PN 2A PG 1 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700338 ER PT J AU Liu, X Stamps, RL Sooryakumar, R Prinz, GA AF Liu, X Stamps, RL Sooryakumar, R Prinz, GA TI Magnetic anisotropies in thick body centered cubic Co SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID BCC COBALT; FILMS; SCATTERING AB Magnetic anisotropies of a 357-Angstrom-thick Co him in the bcc phase were examined using Brillouin light scattering. This film, one of the thickest known bcc Co structures, is found to have a fourfold magnetic anisotropy that is markedly different from those of thinner films. A large possibly strain-induced uniaxial anisotropy is also found. The film is thick enough so that the surface and n=1 bulk magnon are within a few GHz of each other and strongly hybridize. Unusual behavior of the scattering intensities suggest the possible presence of surface anisotropies and/or inhomogeneous internal fields. (C) 1996 American Institute of Physics. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Liu, X (reprint author), OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210, USA. RI Stamps, Robert/E-7304-2011 OI Stamps, Robert/0000-0003-0713-4864 NR 15 TC 6 Z9 6 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5387 EP 5389 DI 10.1063/1.362312 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700342 ER PT J AU Oliver, SA Harris, VG Hamdeh, HH Ho, JC AF Oliver, SA Harris, VG Hamdeh, HH Ho, JC TI EXAFS and magnetic characterization, of inverted bail milled zinc ferrite powders SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 NORTHEASTERN UNIV,CTR ELECTROMAGNET RES,BOSTON,MA 02115. USN,RES LAB,WASHINGTON,DC 20375. WICHITA STATE UNIV,DEPT PHYS,WICHITA,KS 67260. RI Harris, Vincent/A-8337-2009 NR 1 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5431 EP 5431 DI 10.1063/1.361853 PN 2A PG 1 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700359 ER PT J AU Cho, CP Fussell, BK Hung, JY AF Cho, CP Fussell, BK Hung, JY TI A novel integrated electric motor/pump for underwater applications SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB This article presents a novel electric motor/pump system that combines an axial field, permanent magnet motor with a centrifugal pump. This system, unique because the motor permanent magnet rotor and pump impeller vanes are a single unit, provides a compact, reliable, low-noise, and high-power density electrically driven centrifugal pump suitable for underwater applications in which minimizing noise, vibration, and volume are major design objectives. Performance tradeoffs for the electromagnetic analysis were made by three-dimensional finite element analysis models in conjunction with a lumped parameter magnetic circuit model. (C) 1996 American Institute of Physics. C1 UNIV NEW HAMPSHIRE,DURHAM,NH 03824. AUBURN UNIV,AUBURN,AL 36849. RP Cho, CP (reprint author), USN,UNDERSEA WARFARE CTR DIV,NEWPORT,RI 02841, USA. NR 3 TC 5 Z9 6 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5548 EP 5550 DI 10.1063/1.362304 PN 2A PG 3 WC Physics, Applied SC Physics GA UG877 UT WOS:A1996UG87700406 ER PT J AU Wolf, JA Krebs, JJ Idzerda, YU Prinz, GA Kemner, KM AF Wolf, JA Krebs, JJ Idzerda, YU Prinz, GA Kemner, KM TI Structure and magnetism in fee magnetic transition metals on (001) diamond SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 USN,RES LAB,WASHINGTON,DC 20375. NR 0 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5622 EP 5622 DI 10.1063/1.361849 PN 2B PG 1 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800005 ER PT J AU Nordstrom, L Lang, P Zeller, R Dederichs, PH AF Nordstrom, L Lang, P Zeller, R Dederichs, PH TI Quantum well states and interlayer coupling: Co/Cu(100) SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID EXCHANGE; OSCILLATIONS AB The electronic states thar mediate the interlayer exchange coupling and the corresponding coupling strengths are calculated for Co/Cu(100). It is found that some states are strongly confined within the spacer layer This is shown to lead to a strong RKKY-like coupling, but also to some weak contributions from higher harmonics. Weaker confined states only contribute by a rather weak RKKY coupling. (C) 1996 American Institute of Physics. C1 USN, RES LAB, COMPLEX SYST THEORY BRANCH, WASHINGTON, DC 20375 USA. FORSCHUNGSZENTRUM JULICH, INST FESTKORPERFORSCH, D-52425 JULICH, GERMANY. RP Nordstrom, L (reprint author), GEORGE MASON UNIV, INST COMPUTAT SCI & INFORMAT, FAIRFAX, VA 22030 USA. RI Zeller, Rudolf/K-7094-2013 OI Zeller, Rudolf/0000-0002-9462-2649 NR 9 TC 2 Z9 2 U1 0 U2 2 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 APR 15 PY 1996 VL 79 IS 8 BP 5638 EP 5640 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800011 ER PT J AU Koon, NC AF Koon, NC TI Origins of giant biquadratic coupling in CoFe/Mn/CoFe sandwich structures SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 USN,RES LAB,WASHINGTON,DC 20375. NR 2 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 5841 EP 5841 DI 10.1063/1.362206 PN 2B PG 1 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800090 ER PT J AU Krebs, JJ Vavra, W Prinz, GA Cheng, SF Fink, A AF Krebs, JJ Vavra, W Prinz, GA Cheng, SF Fink, A TI Perpendicular transport and magnetic properties in patterned multilayer magnetic microstructures SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID GIANT MAGNETORESISTANCE; AG/CO MULTILAYERS; RESISTANCE AB Using micron-level photolithography, we have prepared a set of patterned multilayer samples which have the form [Co/Cu/NiFeCo/Cu]x10 and which permit perpendicular current transport through the structure. Based on vibrating sample magnetometry, the multilayer stacks show a loss of approximate to 2 Angstrom of magnetic material at each interface. The magnetoresistance was measured as a function of temperature, magnetic layer thickness, and element size and the Delta R/R values range up to 8% at 300 K and 18% at 10 K. The thickness dependent data are modeled using an extension of existing methods and can be fit using comparable resistivity, interface resistance, and spin asymmetry parameters. The magnetic fringe fields of the elements have an important effect on the observed R vs H curves. (C) 1996 American Institute of Physics. C1 USN,CTR SURFACE WARFARE,SILVER SPRING,MD 20910. NONVOLATILE ELECT,EDEN PRAIRIE,MN 55344. RP Krebs, JJ (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 10 TC 6 Z9 6 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 6084 EP 6089 DI 10.1063/1.361892 PN 2B PG 6 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800184 ER PT J AU Teter, JP Hathaway, KB Clark, AE AF Teter, JP Hathaway, KB Clark, AE TI Zero field damping capacity in (TbxDy1-x)Fe-y SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB Materials with a large capacity to dissipate mechanical energy are of interest for passive vibration damping. We have measured the zero-field damping capacity of the giant magnetostrictive terbium-dysprosium-iron compounds by quasistatic stress-strain hysteresis loops. The magnetization and strain of the samples were measured for increasing and decreasing compressive stresses, up to 50 MPa. The zero-field, room temperature damping capacity (Delta W/W) was calculated from the stressstrain loops and is plotted against maximum stress. The damping capacity maximum for the alloy with the nominal Terfenol-D composition occurs at 4.1 MPa with the value 1.75 which corresponds to Q(-1)=0.28. The damping is almost independent of stress in a multi-phase sample, (Tb0.6Dy0.4)Fe-1.4, which contains both Laves phase and elemental rare earth. (C) 1996 American Institute of Physics. C1 CLARK ASSOCIATES,ADELPHI,MD 20783. RP Teter, JP (reprint author), USN,CTR SURFACE WARFARE,SILVER SPRING,MD 20903, USA. NR 2 TC 31 Z9 31 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 6213 EP 6215 DI 10.1063/1.362074 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800227 ER PT J AU Cullen, JR WunFogle, M Restorff, JB Teter, JP Clark, AE AF Cullen, JR WunFogle, M Restorff, JB Teter, JP Clark, AE TI Anomolous Delta E effects in TbDyZn alloys SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB The temperature dependence of Young's modulus has been measured for a series of Tb1-xDyxZn pseudobinary compounds with x ranging from 0 to 1. From the sharp dips in the modulus vs temperature data, the reorientation transition temperatures have been determined, and the magnetic phase diagram deduced. Magnetization measurements taken on the same samples show less pronounced features at the corresponding temperatures. (C) 1996 American Institute of Physics. C1 CLARK ASSOCIATES,ADELPHI,MD 20783. RP Cullen, JR (reprint author), USN,CTR SURFACE WARFARE,CADEROCK DIV,SILVER SPRING,MD 20903, USA. NR 11 TC 8 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 6216 EP 6218 DI 10.1063/1.362075 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800228 ER PT J AU Cheng, SF Teter, JP Lubitz, P Miller, MM Hoines, L Krebs, JJ Schaefer, DM Prinz, GA AF Cheng, SF Teter, JP Lubitz, P Miller, MM Hoines, L Krebs, JJ Schaefer, DM Prinz, GA TI Factors affecting performance of NiO biased giant magnetoresistance structures SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc AB We have made spin-valve structures of Permalloy/Cu/Co by sputtering or electron-beam deposition onto the antiferromagnetic oxide NiO. The oxides were made either by deposition of the metals and subsequent oxidation or by growing them in situ using reactive sputtering. The magnetic properties of the giant magnetoresistance structures were studied by magnetoresistance, vibrating sample magnetometry, and ferromagnetic resonance methods. The oxides were characterized by x-ray diffraction and atomic force microscopy. We studied surface roughness and structure as functions of thickness and oxidation temperature and correlated the oxide properties with the magnetic performance. We found that the metal layer roughened during the postdeposition oxidation process and that the resulting oxide layers were very effective in pinning the direction of the magnetic moment of adjacent metal films. Coercive fields over 500 Oe were obtained for Co overlayers on NiO films but the exchange bias field was generally less than 100 Oe and was not strongly dependent on the roughness. The beneficial effects of this strong pinning were offset to some degree by higher switching fields required in spin-valve structures deposited over the Co. We also made reactively sputtered oxide antiferromagnetic films which had smoother surfaces than those made by postdeposition oxidation. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Cheng, SF (reprint author), USN,CTR SURFACE WARFARE,WHITE OAK LAB,SILVER SPRING,MD 20903, USA. NR 9 TC 21 Z9 21 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 6234 EP 6236 DI 10.1063/1.362079 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800234 ER PT J AU Dorsey, PC Lubitz, P Chrisey, DB Horwitz, JS AF Dorsey, PC Lubitz, P Chrisey, DB Horwitz, JS TI CaFe2O4 thin films grown on (100)MgO substrates using pulsed laser deposition SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID COBALT FERRITE; CO2+ AB Thin films (approximate to 0.4 mu m) of cobalt ferrite (CoFe2O4) have been grown on single-crystal (100) MgO substrates using pulsed laser deposition (PLD). The phase, orientation, and microstructure of the as-deposited films were investigated as a function of substrate temperature (i.e., 200-800 degrees C) at a constant oxygen deposition pressure of 30 mTorr. The as-deposited films were found to be single phase, well oriented, and approximately matching the stoichiometry of the target, but the cubic lattice constant of the films depended on the substrate temperature indicating that the films were strained. The greatest effect of-the substrate temperature was on the magnetic properties of the as-deposited films. At 800 degrees C, 4 pi M(s) was measured to be 5370 G which is approximately the accepted bulk value for cobalt ferrite. In addition, PLD cobalt ferrite films grown at substrate temperatures of 600 and 800 degrees C exhibited a uniaxial magnetic anisotropy with an easy direction normal to the film plane. Films grown at 200 and 400 degrees C also exhibited a uniaxial magnetic anisotropy but possessed a planar easy direction. (C) 1996 American Institute of Physics. RP Dorsey, PC (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 12 TC 112 Z9 114 U1 7 U2 63 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 6338 EP 6340 DI 10.1063/1.361991 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800278 ER PT J AU Idzerda, YU Chakarian, V Gutierrez, CJ Prinz, GA Kao, CC Park, JH Meigs, G Chen, CT AF Idzerda, YU Chakarian, V Gutierrez, CJ Prinz, GA Kao, CC Park, JH Meigs, G Chen, CT TI Structural and magnetic studies of heteromagnetic multilayers by reflectivity of circularly polarized soft x rays SO JOURNAL OF APPLIED PHYSICS LA English DT Meeting Abstract C1 USN,RES LAB,WASHINGTON,DC 20375. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. AT&T BELL LABS,MURRAY HILL,NJ 07974. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 6492 EP 6492 DI 10.1063/1.362452 PN 2B PG 1 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800334 ER PT J AU Chakarian, V Idzerda, YU Kemner, KM Park, JH Meigs, G Chen, CT AF Chakarian, V Idzerda, YU Kemner, KM Park, JH Meigs, G Chen, CT TI Giant magnetic effects in the L-edge extended x-ray absorption fine structure of 3d transition metals SO JOURNAL OF APPLIED PHYSICS LA English DT Article; Proceedings Paper CT 40th Annual Conference on Magnetism and Magnetic Materials CY NOV 06-09, 1995 CL PHILADELPHIA, PA SP Amer Inst Phys, IEEE, Magnet Soc, Minerals Met & Mat Soc, Amer Soc Testing & Mat, USN, Off Naval Res, Amer Ceram Soc ID SPIN AB A systematic extended x-ray absorption fine structure (EXAFS) study at the L edges of ferromagnetic Fe, Co, and Ni thin films has been conducted using circular polarized soft x rays. A very large helicity dependence has been observed in the L-edge EXAFS spectra. Surprisingly, in contradiction with prior works, these magnetic EXAFS results indicate a nonlinear dependence of this effect on the magnetic polarization of the scattering atom. The data further indicate that the dominant scattering paths responsible for the effect are different from those responsible for EXAFS. A discussion of the results in relation to the present understanding of the underlying mechanism and its ramifications to the existing theoretical frameworks is also presented. (C) 1996 American Institute of Physics. C1 USN,RES LAB,WASHINGTON,DC 20375. AT&T BELL LABS,MURRAY HILL,NJ 07974. NR 19 TC 8 Z9 8 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1996 VL 79 IS 8 BP 6493 EP 6495 DI 10.1063/1.361980 PN 2B PG 3 WC Physics, Applied SC Physics GA UG878 UT WOS:A1996UG87800335 ER PT J AU Sahiner, A Croft, M Zhang, Z Greenblatt, M Perez, I Metcalf, P Jhans, H Liang, G Jeon, Y AF Sahiner, A Croft, M Zhang, Z Greenblatt, M Perez, I Metcalf, P Jhans, H Liang, G Jeon, Y TI Electronic structure anisotropy and d-configuration in Ni-based materials SO PHYSICAL REVIEW B LA English DT Article ID RAY-ABSORPTION SPECTROSCOPY; MAGNETIC-PROPERTIES; LA2NIO4; POLARONS; ND2NIO4 AB Ni K-edge x-ray-absorption spectroscopy (XAS) measurements on a series of perovskite-layer-based nick-elate compounds, with varying formal Ni valence, are presented. Spectral features that vary systematically with the Ni configuration are identified for these Ruddlesden-Popper phase and Sr substituted Ln(2-x)Sr(x)NiO(4) (Ln=La and Nd) materials. Selected polarized XAS results on the La2-xSrxNiO4 system emphasize that a collapse of the Ni 4p(sigma)-4p(pi) energy separation accompanies the substantial contraction of the apical Ni-O bond length in this series. In view of this, it is suggested that a displacement of the apical oxygen (O-ab) could play an important role in the small polarons previously proposed to form in this system. The polarized XAS results also provide evidence for in-plane character for the Ni-site component of the doped holes in this system. The XAS evidence supporting an increasing Ni d(7) ground-state admixture in these materials, with increasing formal Ni valence, is discussed. This discussion is couched in terms of simplified Ni d configuration modeling, which emphasizes the close energetic proximity of the Ni d(8) state to O p states in these systems. C1 RUTGERS STATE UNIV,DEPT CHEM,PISCATAWAY,NJ 08855. USN,AIR WARFARE CTR,DIV AIRCRAFT,PATUXENT RIVER,MD 20670. PURDUE UNIV,DEPT CHEM,PURDUE,IN 47907. SAM HOUSTON STATE UNIV,DEPT PHYS,HUNTSVILLE,TX 77341. JEONJU UNIV,DEPT PHYS,CHONJU 560759,SOUTH KOREA. RP Sahiner, A (reprint author), RUTGERS STATE UNIV,DEPT PHYS,PISCATAWAY,NJ 08855, USA. NR 23 TC 19 Z9 19 U1 4 U2 20 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD APR 15 PY 1996 VL 53 IS 15 BP 9745 EP 9752 DI 10.1103/PhysRevB.53.9745 PG 8 WC Physics, Condensed Matter SC Physics GA UJ296 UT WOS:A1996UJ29600050 ER PT J AU Kroes, GJ Wiesenekker, G Baerends, EJ Mowrey, RC AF Kroes, GJ Wiesenekker, G Baerends, EJ Mowrey, RC TI Competition between vibrational excitation and dissociation in collisions of H-2 with Cu(100) SO PHYSICAL REVIEW B LA English DT Article ID DEPENDENT SCHRODINGER-EQUATION; METAL-SURFACES; ENERGY; APPROXIMATION; ADSORPTION; D2; SCATTERING; EXCHANGE; ACCURATE; CU(111) AB A four-dimensional dynamics study was performed on vibrational excitation and dissociation of H-2 in collisions with Cu(100). The potential-energy surface was taken from density-functional calculations. Large probabilities for vibrational excitation (> 10%) are obtained. Two-dimensional fixed-site calculations show that the vibrational excitation is due to impacts on the top site. Impacts on the bridge acid hollow sites are more efficient in causing dissociation. C1 USN, RES LAB, THEORET CHEM SECT, WASHINGTON, DC 20375 USA. RP FREE UNIV AMSTERDAM, DE BOELELAAN 1083, 1081 HV AMSTERDAM, NETHERLANDS. RI Baerends, Evert Jan/F-7206-2011 OI Baerends, Evert Jan/0000-0002-3045-4906 NR 31 TC 50 Z9 50 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD APR 15 PY 1996 VL 53 IS 15 BP 10397 EP 10401 DI 10.1103/PhysRevB.53.10397 PG 5 WC Physics, Condensed Matter SC Physics GA UJ296 UT WOS:A1996UJ29600128 ER PT J AU Thibado, PM Kneedler, E Jonker, BT Bennett, BR Shanabrook, BV Whitman, LJ AF Thibado, PM Kneedler, E Jonker, BT Bennett, BR Shanabrook, BV Whitman, LJ TI Nucleation and growth of Fe on GaAs(001)-(2x4) studied by scanning tunneling microscopy SO PHYSICAL REVIEW B LA English DT Article ID INTERFACE; EPITAXY; FILMS; GAAS AB The nucleation and growth of Fe on GaAs(001)-(2x4) has been studied in situ with scanning tunneling microscopy. The growth is dominated by the structure of the substrate reconstruction. Fe initially forms stable six- to eight-atom two-dimensional islands confined to the first-layer As-dimer rows. The islands preferentially coalesce along the rows, leading to an anisotropic film morphology that persists for at least the first 50 Angstrom of growth. These results provide insight into the growth mode of Fe on GaAs surfaces and have implications for the magnetic properties of ultrathin Fe films. RP Thibado, PM (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Bennett, Brian/A-8850-2008; Whitman, Lloyd/G-9320-2011 OI Bennett, Brian/0000-0002-2437-4213; Whitman, Lloyd/0000-0002-3117-1174 NR 17 TC 52 Z9 52 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD APR 15 PY 1996 VL 53 IS 16 BP 10481 EP 10484 PG 4 WC Physics, Condensed Matter SC Physics GA UJ485 UT WOS:A1996UJ48500012 ER PT J AU Flatte, ME Byers, JM AF Flatte, ME Byers, JM TI Theory of a scanning tunneling microscope with a two-protrusion tip SO PHYSICAL REVIEW B LA English DT Article ID SPECTROSCOPY; SUPERCONDUCTOR; IMPURITY AB We consider a scanning tunneling microscope (STM) such that tunneling occurs through two atomically sharp protrusions on its tip. When the two protrusions are separated by at least several atomic spacings, the differential conductance of this STM depends on the electronic transport in the sample between the protrusions. Such two-protrusion tips commonly occur during STM tip preparation. We explore possible applications to probing dynamical impurity potentials on a metallic surface and local transport in an anisotropic superconductor. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Flatte, ME (reprint author), UNIV IOWA,DEPT PHYS & ASTRON,IOWA CITY,IA 52242, USA. NR 20 TC 7 Z9 7 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD APR 15 PY 1996 VL 53 IS 16 BP 10536 EP 10539 PG 4 WC Physics, Condensed Matter SC Physics GA UJ485 UT WOS:A1996UJ48500026 ER PT J AU Starke, K Kaduwela, AP Liu, Y Johnson, PD VanHove, MA Fadley, CS Chakarian, V Chaban, EE Meigs, G Chen, CT AF Starke, K Kaduwela, AP Liu, Y Johnson, PD VanHove, MA Fadley, CS Chakarian, V Chaban, EE Meigs, G Chen, CT TI Spin-polarized photoelectrons excited by circularly polarized radiation from a nonmagnetic solid SO PHYSICAL REVIEW B LA English DT Article ID RESOLVED PHOTOEMISSION; SYNCHROTRON RADIATION; PHOTO-ELECTRONS; XENON ATOMS; MONOCHROMATORS; DIFFRACTION AB We report a spin analysis of core-level photoelectrons excited by circularly polarized x rays from a nonmagnetic solid. In a combined experimental and theoretical study, we show that the spin-orbit-split W 4f(7/2) and 4f(5/2) photoemission lines from W(110) exhibit high spin polarizations of opposite sign that vary with energy and emission direction. These results suggest the study of the magnetic structure of nonmagnetic/ferromagnetic interfaces formed on high-atomic-number substrates by spin-polarized photoelectron diffraction. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. USN,RES LAB,WASHINGTON,DC 20375. RP Starke, K (reprint author), AT&T BELL LABS,600 MT AVE,MURRAY HILL,NJ 07974, USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 33 TC 20 Z9 20 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD APR 15 PY 1996 VL 53 IS 16 BP 10544 EP 10547 PG 4 WC Physics, Condensed Matter SC Physics GA UJ485 UT WOS:A1996UJ48500028 ER PT J AU Gammon, D Snow, ES Shanabrook, BV Katzer, DS Park, D AF Gammon, D Snow, ES Shanabrook, BV Katzer, DS Park, D TI Fine structure splitting in the optical spectra of single GaAs quantum dots SO PHYSICAL REVIEW LETTERS LA English DT Article ID POLARITON; EXCITONS; WELLS; BAND AB We report a photoluminescence study of excitons localized by interface fluctuations in a narrow GaAs/AlGaAs quantum well. This type of structure provides a valuable system for the optical study of quantum dots. By reducing the area of the sample studied down to the optical near-field regime, only a few dots are probed. With resonant excitation we measure the excited-state spectra of single quantum dots. Many of the spectral lines are linearly polarized with a fine structure splitting of 20-50 mu eV. These optical properties are consistent with the characteristic asymmetry of the interface fluctuations. RP Gammon, D (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Katzer, D. Scott/N-7841-2013 NR 20 TC 805 Z9 812 U1 8 U2 80 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 15 PY 1996 VL 76 IS 16 BP 3005 EP 3008 DI 10.1103/PhysRevLett.76.3005 PG 4 WC Physics, Multidisciplinary SC Physics GA UF379 UT WOS:A1996UF37900045 ER PT J AU VanMeter, ML Kampe, SL Christodoulou, L AF VanMeter, ML Kampe, SL Christodoulou, L TI Mechanical properties of near-gamma titanium aluminides reinforced with high volume percentages of TiB2 SO SCRIPTA MATERIALIA LA English DT Article C1 VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,LONDON,ENGLAND. RP VanMeter, ML (reprint author), USN,AIR WARFARE CTR,DIV AIRCRAFT,PATUXENT RIVER,MD 20670, USA. NR 15 TC 35 Z9 37 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD APR 15 PY 1996 VL 34 IS 8 BP 1251 EP 1256 DI 10.1016/1359-6462(95)00671-0 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA TZ629 UT WOS:A1996TZ62900011 ER PT J AU Guha, S Steiner, P Kozlowski, F Lang, W AF Guha, S Steiner, P Kozlowski, F Lang, W TI Excitation wavelength dependence of Raman and photoluminescence spectra of porous Si membranes SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT Symposium I on Porous Silicon - Material, Technology and Devices, at the European-Materials-Research-Society 1995 Spring Conference CY MAY 22-26, 1995 CL STRASBOURG, FRANCE SP European Mat Res Soc DE luminescence; light scattering; silicon; optical spectroscopy ID SILICON AB A frequency shift and a band narrowing of the Raman and photoluminescence (PL) spectra from porous Si free-standing films are observed with increasing excitation wavelength. We attribute this to a distribution of particle size in Si nanostructures. From the PL and Raman band shapes we determine the energy gap distribution and particle size in Si nanostructures. C1 FRANUNHOFER INST SOLID STATE TECHNOL,W-8000 MUNICH,GERMANY. RP Guha, S (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Lang, Walter/G-3835-2011; OI Lang, Walter/0000-0002-9813-5231 NR 11 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD APR 15 PY 1996 VL 276 IS 1-2 BP 73 EP 75 DI 10.1016/0040-6090(95)08049-X PG 3 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA UU268 UT WOS:A1996UU26800019 ER PT J AU Kovalev, D BenChorin, M Diener, J Koch, F Kux, A Efros, AL Rosen, M Gippius, NA Tikhodeev, SG AF Kovalev, D BenChorin, M Diener, J Koch, F Kux, A Efros, AL Rosen, M Gippius, NA Tikhodeev, SG TI Polarization of porous silicon photoluminescence: Alignment and built-in anisotropy SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT Symposium I on Porous Silicon - Material, Technology and Devices, at the European-Materials-Research-Society 1995 Spring Conference CY MAY 22-26, 1995 CL STRASBOURG, FRANCE SP European Mat Res Soc DE luminescence; anisotropy; dielectric properties; silicon ID QUANTUM AB We report the observation of the anisotropy of the polarization properties of the porous Si photoluminescence. In the edge excitation geometry (exciting light incident on a cleaved edge of the sample) the luminescence polarization is aligned mainly in the [100] direction normal to the surface. The effect is described within the framework of a dielectric model in which porous Si is considered as an aggregate of slightly deformed, elongated and/or flattened, dielectric elliptical Si nanocrystals with preferred orientation normal to the surface. C1 UNIV GRENOBLE 1,SPECTROMETRIE PHYS LAB,F-38402 ST MARTIN DHERES,FRANCE. USN,RES LAB,BEAM THEORY SECT,WASHINGTON,DC 20375. RUSSIAN ACAD SCI,INST GEN PHYS,MOSCOW 117333,RUSSIA. RP Kovalev, D (reprint author), TECH UNIV MUNICH,DEPT PHYS E16,D-85747 GARCHING,GERMANY. RI Tikhodeev, Sergei/A-5452-2016 OI Tikhodeev, Sergei/0000-0001-5940-055X NR 10 TC 10 Z9 10 U1 2 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD APR 15 PY 1996 VL 276 IS 1-2 BP 120 EP 122 DI 10.1016/0040-6090(95)08074-0 PG 3 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA UU268 UT WOS:A1996UU26800031 ER PT J AU Bouamrane, P Tadjeddine, A Butler, JE Tenne, R LevyClement, C AF Bouamrane, P Tadjeddine, A Butler, JE Tenne, R LevyClement, C TI Electrochemical study of diamond thin films in neutral and basic solutions of nitrate SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE electrochemistry; diamond; thin films; nitrate ID ELECTRODES; REDUCTION; IMPEDANCE AB The electrochemical behavior of boron-doped diamond films has been investigated in a number of neutral and alkaline solutions with and without nitrate ions. Two kinds of diamond electrode were studied: self-supported film (100 mu m) (sample A) and diamond film (10 mu m) supported on a Si substrate (sample B). It was found that water oxidation and reduction appear at much larger polarizations for diamond electrodes, as compared with platinum and platinized platinum electrodes. In particular, the higher (cathodic) overpotential for hydrogen reduction permits efficient nitrate reduction to ammonia. The underlying Si substrate is shown to take part in the electrochemistry of the diamond electrodes. In the case of the Si-supported electrode (sample B) the reaction with the Si substrate was imminent. For the free-standing diamond electrode (sample A) various impurities in the grain boundaries and at the back of the electrode, including the back metallic contact, intervened with the electrochemistry of the diamond electrode, but to a much lesser extent than with sample B. Meticulous cleaning and careful working practices permitted this interference to be excluded altogether in sample A. C1 UNIV PARIS SUD 11,LURE,F-91405 ORSAY,FRANCE. USN,RES LABS,WASHINGTON,DC 20375. WEIZMANN INST SCI,DEPT MAT & INTERFACES,IL-76100 REHOVOT,ISRAEL. RP Bouamrane, P (reprint author), LPSB,CNRS UPR 1332,1 PL ARISTIDE BRIAND,F-92195 MEUDON,FRANCE. RI Butler, James/B-7965-2008 OI Butler, James/0000-0002-4794-7176 NR 19 TC 58 Z9 58 U1 1 U2 8 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD APR 12 PY 1996 VL 405 IS 1-2 BP 95 EP 99 PG 5 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA UN547 UT WOS:A1996UN54700010 ER PT J AU Pauls, T Johnston, KJ Wilson, TL AF Pauls, T Johnston, KJ Wilson, TL TI Formaldehyde absorption toward Sagittarius A SO ASTROPHYSICAL JOURNAL LA English DT Article DE Galaxy, center; ISM, individual (Sagittarius A); ISM, molecules ID GALACTIC-CENTER; MOLECULAR GAS; EMISSION; DYNAMICS; COMPLEX; GALAXY; KILOMETERS; AMMONIA; H2CO AB Observations of the 1(10)-1(11) line of formaldehyde with an angular resolution of 9.5 '' x 20.6 '' (P.A. = 4 degrees east of north) toward Sgr A are presented. The velocity resolution is 3 km s(-1), and the velocity range extends from -220 to +154 km s(-1). The H2CO line data show that the molecular gas is distributed in clouds ranging in mass from 10(3.5) to 10(4.8) Mg-., with a typical density of 10(5.5) cm(-3). These clouds are estimated to be gravitationally stable at present but will have lifetimes of less than 10(6) yr because of tidal forces From Sgr A*. There appears to be an underabundance of formaldehyde in the Galactic center region and particularly in the circumnuclear disk. This may be due to destruction by shocks in this region. C1 USN OBSERV,WASHINGTON,DC 20392. MAX PLANCK INST RADIOASTRON,D-53121 BONN,GERMANY. RP Pauls, T (reprint author), USN,RES LAB,REMOTE SENSING DIV,CODE 7213,WASHINGTON,DC 20375, USA. NR 27 TC 5 Z9 5 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 10 PY 1996 VL 461 IS 1 BP 223 EP 230 DI 10.1086/177050 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UD646 UT WOS:A1996UD64600017 ER PT J AU Butler, RP Bell, RA Hindsley, RB AF Butler, RP Bell, RA Hindsley, RB TI The effect of velocity gradients on Cepheid spectra: Models SO ASTROPHYSICAL JOURNAL LA English DT Article DE Cepheids; stars, atmospheres; stars, fundamental parameters; stars, individual (eta Aquilae); stars, oscillations ID PERIOD-LUMINOSITY RELATION; CLASSICAL CEPHEIDS; INFRARED-SPECTROSCOPY; ATMOSPHERIC MOTIONS; COLOR EXCESSES; ETA-AQUILAE; H-ALPHA; STARS; LINE; DISTANCES AB High-resolution observations of eta Aql and other Cepheids have revealed differences in the radial velocity curves from the spectral lines of elements having differing ionization states and excitation energies. The effect of atmospheric velocity gradients on these differential radial velocity curves is investigated with synthetic spectra calculated from model hydrostatic stellar atmospheres appropriate for Cepheids. A number of velocity gradients have been kinematically introduced in these models. It is shown that a significant velocity gradient is needed near the phase of maximum infall velocity to account for the line profile asymmetries and velocity differences observed in the spectrum of eta Aql. The effect of this velocity gradient is to reduce the amplitude of the pulsational velocity curve at optical depth tau = 2/3 by 20% and to decrease the gamma velocity by 2 km s(-1) relative to the standard assumption of a comoving atmosphere. The Barnes-Evans method has been used to analyze eta Aql, taking this velocity gradient into account. The resulting radius and distance are reduced by about 17%, compared to the result found earlier for a comoving atmosphere, while the mean M(v) changes from -4.47 to -4.08. C1 SAN FRANCISCO STATE UNIV,DEPT PHYS & ASTRON,SAN FRANCISCO,CA 94132. UNIV MARYLAND,DEPT ASTRON,COLLEGE PK,MD 20742. USN OBSERV,DEPT ASTRON,WASHINGTON,DC 20372. RP Butler, RP (reprint author), UNIV CALIF BERKELEY,DEPT ASTRON,601 CAMPBELL HALL,BERKELEY,CA 94720, USA. RI Butler, Robert/B-1125-2009 NR 51 TC 26 Z9 26 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 10 PY 1996 VL 461 IS 1 BP 362 EP 371 DI 10.1086/177064 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UD646 UT WOS:A1996UD64600031 ER PT J AU Feldman, U Doschek, GA Behring, WE AF Feldman, U Doschek, GA Behring, WE TI Electron temperature and emission measure determinations of very faint solar flares SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun, flares; Sun, X-rays, gamma rays ID DIELECTRONIC SATELLITE SPECTRA; HELIUM-LIKE IONS; LINES AB We have studied 28 flares in the X-ray magnitude range of A2-A9 using high-resolution Bragg crystal spectrometer data obtained from instrumentation flown on the Yohkoh spacecraft. Flares in the A-class category can be detected in spectral lines of He-like ions formed at low temperatures. Their average temperature is approximately 5 x 10(6) K, and their emission measure as determined from the S XV resonance line near 5 Angstrom varies between 2 x 10(46) and 1 x 10(48) Cm-3. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP Feldman, U (reprint author), USN,RES LAB,EO HULBURT CTR SPACE RES,CODE 7608,WASHINGTON,DC 20375, USA. NR 16 TC 16 Z9 16 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 10 PY 1996 VL 461 IS 1 BP 465 EP 471 DI 10.1086/177073 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UD646 UT WOS:A1996UD64600040 ER PT J AU Gulian, AM VanVechten, D AF Gulian, AM VanVechten, D TI Electron-hole branch imbalance in superconductors initiated by absorption of high-energy quanta SO MODERN PHYSICS LETTERS B LA English DT Article ID TUNNEL-JUNCTION DETECTORS; RELAXATION AB The creation of quasiparticle branch imbalance in superconductors, when pumped by high-energy quanta, is considered. The physical basis for imbalance creation lies in the geometrical difference between the electron- and hole-like excitation densities of states in momentum space. Simple analytical solutions for distribution functions of electron- and hole-like excitations are derived using appropriately modified kinetic equations. The relevance of results to the problem of high-energy particle detection is discussed. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Gulian, AM (reprint author), ARMENIAN ACAD SCI,INST PHYS RES,ASHTARAK 378410,ARMENIA. NR 22 TC 1 Z9 1 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-9849 J9 MOD PHYS LETT B JI Mod. Phys. Lett. B PD APR 10 PY 1996 VL 10 IS 8 BP 329 EP 338 DI 10.1142/S0217984996000377 PG 10 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA UU571 UT WOS:A1996UU57100003 ER PT J AU Harris, VG Oliver, SA Ayers, JD Das, BN Koon, NC AF Harris, VG Oliver, SA Ayers, JD Das, BN Koon, NC TI Reduced-temperature crystallization of thin amorphous Fe80B20 films studied via empirical modeling of extended x-ray absorption fine structure SO APPLIED PHYSICS LETTERS LA English DT Article ID KINETICS; ALLOYS AB The evolution of the local atomic environment around Fe atoms in very thin (15 nm), amorphous, partially crystallized and fully crystallized films of Fe80B20 was studied using extended x-ray absorption fine structure (EXAFS) measurements. The relative atomic fraction of each crystalline phase present in the annealed samples was extracted from the Fe EXAFS data by a least-squares fitting procedure, using data collected from t-Fe3B, t-Fe2B, and alpha-Fe standards. The type and relative fraction of the crystallization products follows the trends previously measured in Fe80B20 melt-spun ribbons, except for the fact that crystallization temperatures are approximate to 200 K lower than those measured in bulk equivalents. This greatly reduced crystallization temperature may arise from the dominant role of surface nucleation sites in the crystallization of very thin amorphous films. (C) 1996 American Institute of Physics. C1 NORTHEASTERN UNIV,CTR ELECTROMAGNET RES,BOSTON,MA 02115. RP Harris, VG (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Harris, Vincent/A-8337-2009 NR 14 TC 7 Z9 7 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 8 PY 1996 VL 68 IS 15 BP 2073 EP 2075 DI 10.1063/1.116307 PG 3 WC Physics, Applied SC Physics GA UD974 UT WOS:A1996UD97400014 ER PT J AU Harris, VG Koon, NC Williams, CM Zhang, Q Abe, M Kirkland, JP AF Harris, VG Koon, NC Williams, CM Zhang, Q Abe, M Kirkland, JP TI Cation distribution in NiZn-ferrite films via extended x-ray absorption fine structure SO APPLIED PHYSICS LETTERS LA English DT Article AB We have applied extended x-ray absorption fine structure (EXAFS) spectroscopy to study the cation distribution in a series of spin-sprayed NiZn-ferrite films. A least-squares fitting of experimental EXAFS data with theoretical, multiple-scattering, EXAFS data allowed the quantitative determination of site distributions for all transition metal cations. (C) 1996 American Institute of Physics. C1 MORGAN STATE UNIV,BALTIMORE,MD 21239. TOKYO INST TECHNOL,MEGURO KU,TOKYO 152,JAPAN. SFA INC,LANDOVER,MD 20785. RP Harris, VG (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Harris, Vincent/A-8337-2009 NR 11 TC 65 Z9 66 U1 0 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD APR 8 PY 1996 VL 68 IS 15 BP 2082 EP 2084 DI 10.1063/1.115591 PG 3 WC Physics, Applied SC Physics GA UD974 UT WOS:A1996UD97400017 ER PT J AU Marchesoni, F Gammaitoni, L Bulsara, AR AF Marchesoni, F Gammaitoni, L Bulsara, AR TI Spatiotemporal stochastic resonance in a phi(4) model of kink antikink nucleation SO PHYSICAL REVIEW LETTERS LA English DT Article ID SOLITONS; EQUATION AB The synchronization and signal processing properties of a linearly coupled chain of N overdamped bistable elements, subject to a deterministic periodic signal and uncorrelated white noise, are addressed in the continuum limit of a phi(4) field theory. The scaling relations for the optimum noise and coupling strengths that correspond to the observed spatiotemporal stochastic resonance are derived via the phi(4) theory and shown to conform to the results of earlier numerical simulations in the large N limit C1 HARVARD UNIV, DEPT PHYS, CAMBRIDGE, MA 02138 USA. UNIV PERUGIA, VIRGO PROJECT, IST NAZL FIS NUCL, DIPARTIMENTO FIS, I-06100 PERUGIA, ITALY. USN COMMAND, CONTROL & OCEAN SURVEILLANCE CTR, RES DEV TESTING & ENGN DIV, SAN DIEGO, CA 92152 USA. RI Gammaitoni, Luca/B-5375-2009; Marchesoni, Fabio/A-1920-2008 OI Gammaitoni, Luca/0000-0002-4972-7062; Marchesoni, Fabio/0000-0001-9240-6793 NR 25 TC 139 Z9 140 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD APR 8 PY 1996 VL 76 IS 15 BP 2609 EP 2612 DI 10.1103/PhysRevLett.76.2609 PG 4 WC Physics, Multidisciplinary SC Physics GA UE190 UT WOS:A1996UE19000002 ER PT J AU Fitzgerald, JP Yap, GPA Rheingold, AL Brewer, CT May, L Brewer, GA AF Fitzgerald, JP Yap, GPA Rheingold, AL Brewer, CT May, L Brewer, GA TI Intermediate-spin iron(III) octaethyltetraazaporphyrinates with weakly coordinating anions: Synthesis, characterization and crystal structure SO JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS LA English DT Article ID S = 3/2; MOLECULAR-STRUCTURE; MAGNETIC-PROPERTIES; FERRIC PORPHYRIN; IRON PORPHYRINS; STATE; COMPLEXES; PERCHLORATE; STEREOCHEMISTRY; SPECTROSCOPY AB The metathesis reaction of AgZ (Z = ClO4-, PF6-, SbF6- or CF3CO2-) with chloroiron(III) 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetraazaporphyrinate octaethyl-5,10,15,20-tetraazaporphyrinate chloride, Fe(oetap)Cl, in tetrahydrofuran or toluene gave the Fe(oetap)Z derivatives in approximately 70% yield. The complexes are air-stable solids but decompose in solution to [Fe(oetap)]O-2 (Z = ClO4- or CF3CO2-) or Fe(oetap)F (Z = PF6- or SbF6-). They have been characterized by variable-temperature magnetic susceptibility measurements and Mossbauer, UV/VIS, IR and ESR spectroscopies. In addition; Fe(oetap)ClO4 has been structurally characterized by single-crystal X-ray diffraction. All of the complexes ate intermediate-spin (S = 3/2) based on their magnetic properties and Mossbauer and ESR spectra. C1 UNIV DELAWARE,DEPT CHEM & BIOCHEM,NEWARK,DE 19716. CATHOLIC UNIV AMER,DEPT CHEM,WASHINGTON,DC 20064. RP Fitzgerald, JP (reprint author), USN ACAD,DEPT CHEM,ANNAPOLIS,MD 21402, USA. NR 41 TC 22 Z9 22 U1 1 U2 4 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0300-9246 J9 J CHEM SOC DALTON JI J. Chem. Soc.-Dalton Trans. PD APR 7 PY 1996 IS 7 BP 1249 EP 1253 DI 10.1039/dt9960001249 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA UF121 UT WOS:A1996UF12100010 ER PT J AU Mintmire, JW AF Mintmire, JW TI Fullerene formation and annealing SO SCIENCE LA English DT Editorial Material ID ELECTRONIC-STRUCTURES; C-60; CARBON; FORM RP Mintmire, JW (reprint author), USN,RES LAB,THEORET CHEM SECT,WASHINGTON,DC 20375, USA. OI Mintmire, John/0000-0002-6551-0349 NR 21 TC 9 Z9 9 U1 0 U2 3 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD APR 5 PY 1996 VL 272 IS 5258 BP 45 EP 46 DI 10.1126/science.272.5258.45 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UD597 UT WOS:A1996UD59700031 ER PT J AU Senaratne, C Zhang, J Baker, MD Bessel, CA Rolison, DR AF Senaratne, C Zhang, J Baker, MD Bessel, CA Rolison, DR TI Zeolite-modified electrodes: Intra- versus extrazeolite electron transfer SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID CARBON-PASTE ELECTRODE; FAUJASITE-TYPE ZEOLITE; ELECTROCHEMICAL-BEHAVIOR; SUPPORTING ELECTROLYTE; ENCAPSULATED COMPLEXES; TIN OXIDE; SILVER; ION; PLATINUM; SPECTROSCOPY AB This paper is solely concerned with the mechanism of electron transfer in zeolite-modified electrodes (ZMEs) where the zeolite has been modified with electroactive transition metal ions or complexes. First, data were obtained from ZMEs prepared with zeolite Y-encapsulated Co(salen) or [Fe(bpy)(3)](2+) complexes (where salen = N,N'-bis(salicylidene)ethylenediammine and bpy = 2,2'-bipyridine). Changes in the cyclic voltammetry seen for such ZMEs in nonaqueous solutions are discussed in terms of the interpretive difficulties that can arise without proper controls and blanks. Specifically, the various methods of complex synthesis and purification and the effects of the electrode materials used in the fabrication of a ZME can give rise to voltammetric features which may be misattributed. Integration of the peak area, repeated voltammetric cycling, and scan-rate dependencies demonstrate that electron transfer occurs outside the zeolite pore system for these zeolite-encapsulated transition metal complexes, i.e., by an extrazeolite mechanism, rather than by an intrazeolite mechanism where electron transfer occurs to an encapsulated complex present within the zeolite framework. Second, data were obtained for transition metal (Ag(I)- and Cu(II)-) exchanged zeolites prepared as ZMEs and studied in aqueous and nonaqueous electrolytes. An extrazeolite mechanism for electron transfer was determined to be operative once effects were considered which arise from changes attributable to metal deposition on electrodes, the nature of the electrode material, and the presence of solution-phase charge and/or size-excluded moieties. C1 USN,RES LAB,SURFACE CHEM BRANCH,WASHINGTON,DC 20375. RP Senaratne, C (reprint author), UNIV GUELPH,GUELPH WATERLOO CTR GRAD WORK CHEM,DEPT CHEM & BIOCHEM,GUELPH,ON N1G 2W1,CANADA. NR 67 TC 76 Z9 78 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD APR 4 PY 1996 VL 100 IS 14 BP 5849 EP 5862 DI 10.1021/jp951923x PG 14 WC Chemistry, Physical SC Chemistry GA UD604 UT WOS:A1996UD60400036 ER PT J AU Bakaltcheva, IB Odeyale, CO Spargo, BJ AF Bakaltcheva, IB Odeyale, CO Spargo, BJ TI Effects of alkanols, alkanediols and glycerol on red blood cell shape and hemolysis SO BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES LA English DT Article DE erythrocyte; hemolysis; polyol; cell shape; dielectric constant; partition coefficient; cryoprotectant toxicity ID HUMAN-ERYTHROCYTE; DIELECTRIC-CONSTANT; MOUSE EMBRYOS; LIPID BILAYER; VITRIFICATION; MEMBRANE; CRYOPRESERVATION; PERMEABILITY; POTASSIUM; ALCOHOLS AB The physicochemical effects of a series of alkanols, alkanediols and glycerol on erythrocyte shape and hemolysis at 4 and 20 degrees C were examined. We calculated the dielectric constant of the incubation medium, D-s, and the dielectric constant of the erythrocyte membrane D-m in the presence of organic solutes, The ratio D-s/D-m = -38.48 at 20 degrees C defines the normal biconcave shape in a medium without hemolytic agents. A decrease in D-s/D-m favors externalization or internalization with consequent hemolysis. Alkanols and alkanediols convert biconcave erythrocytes into echinocytes, which is accompanied by an increase in the projected surface area. Glycerol converts biconcave erythrocytes into stomatocytes, which was accompanied by a marginal decrease in the projected surface area. Progressive externalization in alkanols and alkanediols or internalization in glycerol resulted in a decrease in the projected surface area and the formation of smooth spheres. The degree of shape change induced was related to the degree of hemolysis and the ratio D-s/D-m, A decrease in temperature reduced both the degree of shape change and hemolysis. Our results suggest that physicochemical toxicity may be a result of a temperature dependent hydrophobic interaction between the organic solutes and the membrane and is best interpreted by the ability of the solutes to change D-s and D-m, These results are discussed with respect to the physicochemical constants of the organic solutes. C1 USN,RES LAB,CTR BIOMOLEC SCI & ENGN,WASHINGTON,DC 20375. GEOCENTERS INC,FT WASHINGTON,MD 20744. USN,MED RES INST,DEPT PATHOBIOL,BETHESDA,MD 20889. NR 29 TC 17 Z9 17 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0005-2736 J9 BBA-BIOMEMBRANES JI Biochim. Biophys. Acta-Biomembr. PD APR 3 PY 1996 VL 1280 IS 1 BP 73 EP 80 DI 10.1016/0005-2736(95)00279-0 PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA UE898 UT WOS:A1996UE89800009 PM 8634318 ER PT J AU Rowe, NC AF Rowe, NC TI Using local optimality criteria for efficient information retrieval with redundant information filters SO ACM TRANSACTIONS ON INFORMATION SYSTEMS LA English DT Article DE performance; boolean algebra; conjunction; filters; natural language; optimization; queries ID DOCUMENT-RETRIEVAL; DATABASE SYSTEM; SEARCH AB We consider information retrieval when the data-for instance, multimedia-is computationally expensive to fetch. Our approach uses ''information filters'' to considerably narrow the universe of possibilities before retrieval. We are especially interested in redundant information filters that save time over more general but more costly filters. Efficient retrieval requires that decisions must be made about the necessity, order, and concurrent processing of proposed filters (an ''execution plan''). We develop simple polynomial-time local criteria for optimal execution plans and show that most forms of concurrency are suboptimal with information filters. Although the general problem of finding an optimal execution plan is likely to be exponential in the number of filters, we show experimentally that our local optimality criteria, used in a polynomial-time algorithm, nearly always find the global optimum with 15 filters or less, a sufficient number of filters for most applications. Our methods require no special hardware and avoid the high processor idleness that is characteristic of massive-parallelism solutions to this problem. We apply our ideas to an important application, information retrieval of captioned data using natural-language understanding, a problem for which the natural-language processing can be the bottleneck if not implemented well. RP Rowe, NC (reprint author), USN,POSTGRAD SCH,DEPT COMP SCI,CODE CS-RP,MONTEREY,CA 93943, USA. NR 30 TC 4 Z9 4 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 SN 1046-8188 J9 ACM T INFORM SYST JI ACM Trans. Inf. Syst. PD APR PY 1996 VL 14 IS 2 BP 138 EP 174 DI 10.1145/226163.226165 PG 37 WC Computer Science, Information Systems SC Computer Science GA UG154 UT WOS:A1996UG15400002 ER PT J AU Ammon, HL Du, ZY Gilardi, RD Dave, PR Forohar, F Axenrod, T AF Ammon, HL Du, ZY Gilardi, RD Dave, PR Forohar, F Axenrod, T TI Structure of 1,3,5,7-tetranitro-3,7-diazabicyclo[3.3.0]octane. Structure solution from molecular packing analysis SO ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE LA English DT Article AB The structure was solved with the molecular packing program MOLPAK, starting with a molecular mechanics-geometry optimized model of an isolated molecule. The best predicted crystal structures from the MOLPAK procedure were subjected to lattice energy refinement with the WMIN program. The MOLPAK/WMIN-predicted crystal structure, whose cell parameters were closest to the experimental values. gave an initial R of 0.48 for the 173 data to theta = 25 degrees. Four cycles of least-squares refinement of x, y, z and U gave an R of 0.27 for the 277 data to theta = 30 degrees. Final R = 0.038, wR = 0.044. There are no unusual intermolecular distances and crystal packing is normal. C1 USN,RES LAB,STRUCT MATTER LAB,WASHINGTON,DC 20375. ARDEC,GEOCENTERS INC,LAKE HOPATCONQ,NJ 07849. CUNY CITY COLL,DEPT CHEM,NEW YORK,NY 10031. RP Ammon, HL (reprint author), UNIV MARYLAND,DEPT CHEM & BIOCHEM,COLLEGE PK,MD 20742, USA. NR 17 TC 3 Z9 3 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7681 J9 ACTA CRYSTALLOGR B JI Acta Crystallogr. Sect. B-Struct. Commun. PD APR 1 PY 1996 VL 52 BP 352 EP 356 DI 10.1107/S0108768195010652 PN 2 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA UK561 UT WOS:A1996UK56100018 ER PT J AU Karpouzian, G Librescu, L AF Karpouzian, G Librescu, L TI Nonclassical effects on divergence and flutter of anisotropic swept aircraft wings SO AIAA JOURNAL LA English DT Article ID AEROELASTIC CHARACTERISTICS; WARPING RESTRAINT; COMPOSITE WINGS; BEHAVIOR AB A refined structural model of swept aircraft wings is presented and used to study the associated flutter and divergence instability in an incompressible gas Row. The structural model incorporates nonclassical effects such as anisotropy, heterogeneity, transverse shear, and warping inhibition. An exact solution methodology appropriate for parametric studies is wed to specifically determine the effects of transverse shear and warping restraint on aeroelastic instabilities. The results reveal strong quantitative and qualitative Implications for instability predictions. The solution methodology yields results that are in excellent agreement with an exact approach devised for a special case and provides a high-efficiency mathematical tool for dealing with flutter and divergence instability problems. C1 VIRGINIA POLYTECH INST & STATE UNIV,DEPT ENGN SCI & MECH,BLACKSBURG,VA 24061. RP Karpouzian, G (reprint author), USN ACAD,DEPT AEROSP ENGN,ANNAPOLIS,MD 21402, USA. NR 30 TC 25 Z9 26 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD APR PY 1996 VL 34 IS 4 BP 786 EP 794 DI 10.2514/3.13141 PG 9 WC Engineering, Aerospace SC Engineering GA UC611 UT WOS:A1996UC61100019 ER PT J AU Olson, PE Wallace, MR Grillo, MP Rossetti, RJ Miller, LK AF Olson, PE Wallace, MR Grillo, MP Rossetti, RJ Miller, LK TI Lack of utility of routine chest radiographs in HIV-infected patients SO AIDS LA English DT Letter ID AIDS RP Olson, PE (reprint author), USN,CTR MED,DEPT INTERNAL MED,DIV INFECT DIS,SAN DIEGO,CA 92134, USA. NR 5 TC 5 Z9 5 U1 0 U2 0 PU RAPID SCIENCE PUBLISHERS PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8NH SN 0269-9370 J9 AIDS JI Aids PD APR PY 1996 VL 10 IS 4 BP 446 EP 447 DI 10.1097/00002030-199604000-00018 PG 2 WC Immunology; Infectious Diseases; Virology SC Immunology; Infectious Diseases; Virology GA UE997 UT WOS:A1996UE99700018 PM 8728054 ER PT J AU Clenney, TL Lassen, LF AF Clenney, TL Lassen, LF TI Recreational scuba diving injuries SO AMERICAN FAMILY PHYSICIAN LA English DT Article ID CORD DECOMPRESSION-SICKNESS; BAROTRAUMA; FISTULA; DIVE AB Because of the increasing popularity of recreational scuba diving, primary care physicians should be familiar with common diving injuries. One form of barotrauma, middle ear squeeze, is the most common diving injury. Other important diving injuries include inner ear barotrauma and pulmonary barotrauma. Arterial gas embolism, a potentially life-threatening form of pulmonary barotrauma, requires hyperbaric treatment. Decompression sickness is the result of bubble formation in body tissue. Symptoms of decompression sickness range from joint pain to neurologic or pulmonary problems. Recompression is the mainstay of treatment. RP Clenney, TL (reprint author), USN,NAVAL SCH,EXPLOS ORDNANCE DISPOSAL,309 STRAUSS AVE,INDIAN HEAD,MD 20640, USA. NR 17 TC 17 Z9 17 U1 0 U2 2 PU AMER ACAD FAMILY PHYSICIANS PI KANSAS CITY PA 8880 WARD PARKWAY, KANSAS CITY, MO 64114-2797 SN 0002-838X J9 AM FAM PHYSICIAN JI Am. Fam. Physician PD APR PY 1996 VL 53 IS 5 BP 1761 EP 1766 PG 6 WC Primary Health Care; Medicine, General & Internal SC General & Internal Medicine GA UE743 UT WOS:A1996UE74300029 PM 8623700 ER PT J AU Furgol, EM AF Furgol, EM TI The bishops' wars: Charles I's campaigns against Scotland, 1638-1640 - Fissel,MC SO AMERICAN HISTORICAL REVIEW LA English DT Book Review RP Furgol, EM (reprint author), USN,HIST CTR,WASHINGTON,DC 20350, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER HISTORICAL REVIEW PI WASHINGTON PA 400 A ST SE, WASHINGTON, DC 20003 SN 0002-8762 J9 AM HIST REV JI Am. Hist. Rev. PD APR PY 1996 VL 101 IS 2 BP 482 EP 483 DI 10.2307/2170448 PG 2 WC History SC History GA UF739 UT WOS:A1996UF73900058 ER PT J AU Greason, KL Hemp, JR Maxwell, JM Fetter, JE MorenoCabral, RJ AF Greason, KL Hemp, JR Maxwell, JM Fetter, JE MorenoCabral, RJ TI Limb perfusion during cardiopulmonary support - Reply SO ANNALS OF THORACIC SURGERY LA English DT Letter ID CORONARY ANGIOPLASTY C1 USN,MED CTR,DEPT CLIN INVEST,SAN DIEGO,CA 92134. RP Greason, KL (reprint author), USN,MED CTR,DEPT GEN SURG,SAN DIEGO,CA 92134, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0003-4975 J9 ANN THORAC SURG JI Ann. Thorac. Surg. PD APR PY 1996 VL 61 IS 4 BP 1291 EP 1292 DI 10.1016/0003-4975(96)81295-1 PG 2 WC Cardiac & Cardiovascular Systems; Respiratory System; Surgery SC Cardiovascular System & Cardiology; Respiratory System; Surgery GA UD082 UT WOS:A1996UD08200079 ER PT J AU Wu, C Chen, LG Sun, FR Chen, WZ AF Wu, C Chen, LG Sun, FR Chen, WZ TI General performance characteristics of a finite-speed Carnot refrigerator SO APPLIED THERMAL ENGINEERING LA English DT Article DE refrigerator; performance; endoreversible ID MAXIMUM-POWER; HEAT ENGINES; EFFICIENCY; TIME AB The general performance characteristic of a finite-speed Carnot refrigerator is investigated. The relationship between the coefficient of performance and the cooling load of the refrigerator is obtained for several different heat transfer cases. The result provides a realistic design criterion for actual refrigerators. RP Wu, C (reprint author), USN ACAD,121 BLAKE RD,ANNAPOLIS,MD 21402, USA. NR 14 TC 15 Z9 17 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-4311 J9 APPL THERM ENG JI Appl. Therm. Eng. PD APR PY 1996 VL 16 IS 4 BP 299 EP 303 DI 10.1016/1359-4311(95)00030-5 PG 5 WC Thermodynamics; Energy & Fuels; Engineering, Mechanical; Mechanics SC Thermodynamics; Energy & Fuels; Engineering; Mechanics GA TU185 UT WOS:A1996TU18500003 ER PT J AU Brook, I Yocum, P Frazier, EH AF Brook, I Yocum, P Frazier, EH TI Bacteriology and beta-lactamase activity in acute and chronic maxillary sinusitis SO ARCHIVES OF OTOLARYNGOLOGY-HEAD & NECK SURGERY LA English DT Article ID HEMOLYTIC STREPTOCOCCI; PENICILLIN; CHILDREN; PROTECTION; INFECTION AB Objective: To assess the bacteriology and beta-lactamase enzyme activity in aspirates of 10 acutely and 13 chronically inflamed maxillary sinuses. Results: The predominant organisms isolated in acute sinusitis were Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis, and those found in chronic sinusitis were Prevotella species, Fusobacterium species, and Peptostreptococcus species. Four P-lactamase-producing organisms (BLPOs) were isolated in four specimens (40%) obtained from acutely inflamed sinuses, and 14 BLPOs were recovered from 10 chronically inflamed sinuses (77%). The predominant BLPOs in acute sinusitis were H influenzae, and M catarrhalis; those in chronic sinusitis were Staphylococcus aureus, Prevotella species, Fusobacterium species, and Bacteroides fragilis. Conclusions: beta-Lactamase activity was detected in 12 (three in acute and nine in chronic sinusitis) of the 14 aspirates that contained BLPOs. The detection of beta-lactamase activity in sinus aspirates provides support for the role of BLPOs in the failure of penicillin therapy in sinusitis. C1 USN,MED CTR,DEPT PEDIAT,BETHESDA,MD 20814. USN,MED CTR,DEPT INFECT DIS,BETHESDA,MD 20814. NR 23 TC 50 Z9 54 U1 0 U2 0 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 SN 0886-4470 J9 ARCH OTOLARYNGOL JI Arch. Otolaryngol. Head Neck Surg. PD APR PY 1996 VL 122 IS 4 BP 418 EP 422 PG 5 WC Otorhinolaryngology; Surgery SC Otorhinolaryngology; Surgery GA UE212 UT WOS:A1996UE21200010 PM 8600928 ER PT J AU Dyck, HM Benson, JA vanBelle, GT Ridgway, ST AF Dyck, HM Benson, JA vanBelle, GT Ridgway, ST TI Radii and effective temperatures for K and M giants and supergiants SO ASTRONOMICAL JOURNAL LA English DT Article ID ANGULAR DIAMETER MEASUREMENTS; MICHELSON INTERFEROMETRY; STARS; COOLER; MODEL; VEGA AB Interferometrically determined angular diameters for 37 KO-M8 giant and supergiant stars are presented in this paper. It is shown that the effective temperatures determined for this sample agree with previous determinations made at CERGA and by occultations and that there is no significant difference among the effective temperature scales set by the three investigations. The effective temperature data from the three sources are combined to give a new mean relationship between effective temperature and spectral type extending to spectral types as late as M7, where the precision is approximately +/-95 K at each spectral type. The question of the natural dispersion in the effective temperature scale is discussed and found to lie between +/-40 and +/-80 K. Several new supergiants have been observed and a previous suggestion is confirmed that the supergiant temperature scale is cooler than the corresponding scale for giants. The difference in temperature between the two luminosity classes decreases with decreasing temperature. Linear radii for 22 stars have been computed by combining the angular diameter data with the best available parallax data. The middle M giants have radii approximately 80 times the Solar radius. (C) 1996 American Astronomical Society. C1 USN OBSERV,NPOI,FLAGSTAFF,AZ 86001. NATL OPT ASTRON OBSERV,TUCSON,AZ 85726. RP Dyck, HM (reprint author), UNIV WYOMING,DEPT PHYS & ASTRON,LARAMIE,WY 82071, USA. NR 35 TC 154 Z9 154 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD APR PY 1996 VL 111 IS 4 BP 1705 EP 1712 DI 10.1086/117910 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UB962 UT WOS:A1996UB96200023 ER PT J AU Stone, RC Monet, DG Monet, AKB Walker, RL Ables, HD Bird, AR Harris, FH AF Stone, RC Monet, DG Monet, AKB Walker, RL Ables, HD Bird, AR Harris, FH TI The Flagstaff astrometric scanning transit telescope (FASTT) and star positions determined in the extragalactic reference frame SO ASTRONOMICAL JOURNAL LA English DT Review ID OPTICAL REFERENCE FRAME; PHOTOMETRIC STANDARD STARS; STELLAR RADIO ASTROMETRY; ADDITIONAL RADIO; MERIDIAN CIRCLE; NORTHERN-HEMISPHERE; CELESTIAL EQUATOR; CATALOG; CCD; REFRACTION AB This paper describes the methods used for determining star positions in the extragalactic reference frame with the Flagstaff astrometric scanning transit telescope (FASTT) from drift scan observations. A laser metrology system is used to correct for instrumental motions, and detailed numerical computations are made for atmospheric and room refractions. These and other methods have improved the accuracy of the observations which are currently +/-140 and +/-170 mas, respectively in right ascension and declination for a single observation. Objects as faint as V similar to 17.5 mag are routinely observed with the FASTT, and magnitudes accurate to +/-0.04 mag can also be determined. As discussed in this paper, most of the positional error is caused by anomalous refraction in the atmosphere which places a lower limit on the accuracy of FASTT observations around +/-90 mas in both coordinates. After the Hipparcos/Tycho catalogs become available in a few years, all the FASTT reductions could be made differentially in small fields, wherein the expected accuracy is +/-40 mas in both coordinates for a single observation. The telescope has been automated and is operated remotely. Current observing projects include the densification of star positions in large regions of the sky, linking the optical and radio reference frames together, and determining the positions of faint solar system objects. A discussionis given of the methods used for reducing FASTT drift scan observations to equatorial positions and magnitudes. (C) 1996 American Astronomical Society. RP Stone, RC (reprint author), USN OBSERV, FLAGSTAFF STN, POB 1149, FLAGSTAFF, AZ 86002 USA. NR 103 TC 55 Z9 58 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD APR PY 1996 VL 111 IS 4 BP 1721 EP 1742 DI 10.1086/117913 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UB962 UT WOS:A1996UB96200026 ER PT J AU Bondi, M Padrielli, L Fanti, R Ficarra, A Gregorini, L Mantova, GD Weiler, KW AF Bondi, M Padrielli, L Fanti, R Ficarra, A Gregorini, L Mantova, GD Weiler, KW TI Three epoch VLBI observations at 18 cm of low frequency variable sources SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE quasars, general; BL Lacertae objects, general; galaxies, jets; radio continuum, galaxies ID EXTRAGALACTIC RADIO-SOURCES; VARIABILITY; NGC-1275; SAMPLE; CORE AB We present third epoch VLBI observations at 1.67 GHz of a sample of 20 Low Frequency Variable Sources. The sources have been observed with a global array of 11 radio telescopes, recording in MK 2 mode, with a resolution of similar to 3 mas. We also present an analysis of possible variations in the fringe visibilities between an earlier epoch (1981.8) and the present epoch (1987.9), and compare these changes with those observed between the two epochs 1980.1 and 1981.8. Significant variations have been found in 17 out of 20 sources. In a number of cases the changes are clearly due to flux density variations in the most compact component. Several other cases appear to be due to either an increase in the angular size of a single component or a change in the angular separation between well defined components. Some sources show superluminal motions much like those usually observed at higher frequencies, and some new candidates for superluminal motions are identified. We have also used 408 MHz monitoring data, taken in the period of the VLBI observations, to derive an estimate of the Doppler factors necessary to account for the low frequency variability, and we compare these values with the Doppler factors calculated from the proper motions detected in our VLBI observations. This analysis confirms that two distinct phenomena, intrinsic superluminal beaming and extrinsic scintillation, are responsible for the low frequency variability seen in compact extragalactic radio sources. C1 UNIV MANCHESTER, NUFFIELD RADIO ASTRON LABS, JODRELL BANK, MACCLESFIELD SK11 9DL, CHESHIRE, ENGLAND. UNIV BOLOGNA, DIPARTIMENTO FIS, I-40126 BOLOGNA, ITALY. YORK UNIV, DEPT PHYS & ASTRON, N YORK, ON M3J 1P3, CANADA. NATL RADIO ASTRON OBSERV, AOC, SOCORRO, NM 87801 USA. HARTEBEESTHOEK RADIO ASTRON OBSERV, KRUGERSDORP 1740, SOUTH AFRICA. USN, RES LAB, CTR ADV SPACE SENSING, WASHINGTON, DC 20375 USA. RP Bondi, M (reprint author), CNR, IST RADIOASTRON, VIA GOBETTI 101, I-40129 BOLOGNA, ITALY. NR 33 TC 44 Z9 46 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD APR PY 1996 VL 308 IS 2 BP 415 EP 427 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UE747 UT WOS:A1996UE74700014 ER PT J AU deJager, OC Harding, AK Strickman, MS AF deJager, OC Harding, AK Strickman, MS TI OSSE detection of gamma rays from the Vela synchrotron nebula SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays, observations; ISM, individual (Gum Nebula); ISM, magnetic fields; pulsars, individual (PSR BO833-45); supernova remnants ID PULSAR AB We report on the detection of low-energy gamma-rays from the Vela supernova remnant at the similar to 9 a level with the Oriented Scintillation Spectrometer Experiment (OSSE) instrument on the Compton Gamma Ray Observatory (CGRO). The source exhibits a hard spectrum consistent with a power law of index -1.6 +/- 0.5 in the energy range 0.061 MeV to similar to 0.4 MeV. Contamination by the galactic plane and other sources was found to be insignificant. This spectrum is quite consistent with an extrapolation of the similar to(-1.7) spectrum of the 1' radius compact nebula as seen between optical and 25 keV with imaging instruments. No spectral break is seen between similar to 1 eV and 0.4 MeV, but several arguments indicate that this spectrum should cut off below 40 MeV. The extension of the nebular synchrotron emission to an energy of at least 0.4 MeV implies electron energies up to greater than or similar to 3 x 10(14) eV, which is a factor 10 below the maximum acceleration energy of 3.5 x 10(15) eV set by the polar cap vacuum potential. Imaging and spectral observations indicate that the energy in particles and magnetic field are close to equipartition in the compact nebula, with a mean field strength of similar to 6 x 10(-5) G. Even though only similar to 0.1% of the spin-down power is radiated as synchrotron photons, the inferred particle pressure in the compact nebula is about half the pulsar ram pressure L/4 pi r(2)c in the compact nebula. The relatively weak field allows electrons to escape to relatively large distances from the pulsar, which may explain why the synchrotron nebula is extended by several degrees. C1 NASA, GODDARD SPACE FLIGHT CTR, HIGH ENERGY ASTROPHYS LAB, GREENBELT, MD 20771 USA. USN, RES LAB, DIV SPACE SCI, WASHINGTON, DC 20375 USA. RP deJager, OC (reprint author), POTCHEFSTROOM UNIV CHRISTIAN HIGHER EDUC, DEPT PHYS, SPACE RES UNIT, POTCHEFSTROOM 2520, SOUTH AFRICA. RI Harding, Alice/D-3160-2012 NR 21 TC 27 Z9 27 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 1 PY 1996 VL 460 IS 2 BP 729 EP 734 DI 10.1086/177005 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UB530 UT WOS:A1996UB53000015 ER PT J AU Strickman, MS Grove, JE Johnson, WN Kinzer, RL Kroeger, RA Kurfess, JD Grabelsky, DA Matz, SM Purcell, WR Ulmer, MP Jung, GV AF Strickman, MS Grove, JE Johnson, WN Kinzer, RL Kroeger, RA Kurfess, JD Grabelsky, DA Matz, SM Purcell, WR Ulmer, MP Jung, GV TI OSSE observations of the Vela and Geminga pulsars SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays, observations; pulsars, individual (Vela Pulsar, Geminga) ID ENERGY GAMMA-RADIATION; RAY ASTRONOMY; PSR-0833-45; EMISSION AB The Oriented Scintillation Spectrometer Experiment (OSSE) on board the Compton Gamma Ray Observatory detected the Vela pulsar (PSR B0833 -45) during 1991 August-September, 1992 April-May, and 1993 August. Observed light curves have a two-peak pulse profile similar to that observed at higher energies, although the second peak may be wider in the OSSE light curve. Pulsed emission in the first gamma-ray peak was detected with 4.6 sigma statistical significance in the 0.07-0.6 MeV band in the sum of all three observing periods. The second gamma-ray peak was detected at no more than 3 sigma significance in the same band. Due to the low statistical significance of the observations, little can be said concerning longer term temporal variability. The spectrum is hard at lower energies and, in combination with higher energy data, appears to require a break. in the 20 MeV region. OSSE also observed Geminga during 1992 July, 1993 December, and 1994 July. No significant pulsed emission was observed on any occasion. Upper limits to the pulsed emission suggest, but do not require, a break from the extrapolation of the spectrum measured at higher energies. C1 NORTHWESTERN UNIV,EVANSTON,IL 60208. UNIV SPACE RES ASSOC,WASHINGTON,DC 20024. RP Strickman, MS (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Johnson, Neil/G-3309-2014 NR 34 TC 20 Z9 20 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 1 PY 1996 VL 460 IS 2 BP 735 EP 743 DI 10.1086/177006 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UB530 UT WOS:A1996UB53000016 ER PT J AU Foster, RS Fischer, J AF Foster, RS Fischer, J TI Search for protoplanetary and debris disks around millisecond pulsars SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; infrared, stars; planetary systems; pulsars, general ID PLANETARY SYSTEM; BINARY; PSR1257+12; EVOLUTION; DISCOVERY AB The identification of planetary companions around the nearby millisecond radio pulsar PSR B1257 + 12 implies that planetary formation has occurred in the past evolutionary history of this system. If planetary formation is common around millisecond pulsars and if it occurs by coalescence of small dust particles within a protoplanetary disk, as is thought to have occurred during the formation of the solar system, then it may be possible to detect the presence of protoplanetary dust or a remnant debris disk via thermal infrared emission. We summarize an attempt to detect this emission via a series of 10 mu m observations made toward PSR B1257 + 12 and four other nearby millisecond pulsars using the National Aeronautics and Space Administration (NASA) Infrared Telescope Facility (IRTF) 3 m telescope and the facility bolometer. We also present a simple model for thermal emission from a protoplanetary disk containing grains heated from the pulsar spin-down luminosity. Further, we describe upcoming space-based far-infrared observations that can substantially improve observational limits from the emission of dust that may radiate in the two order of magnitude gap between ground-based accessible mid-infrared and millimeter spectral regions. C1 UNIV HAWAII,INFRARED TELESCOPE FACIL,HONOLULU,HI 96822. RP Foster, RS (reprint author), USN,RES LAB,DIV REMOTE SENSING,CODE 7210,WASHINGTON,DC 20375, USA. NR 38 TC 17 Z9 17 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 1 PY 1996 VL 460 IS 2 BP 902 EP 905 DI 10.1086/177018 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UB530 UT WOS:A1996UB53000028 ER PT J AU Feldman, U Doschek, GA Behring, WE Phillips, KJH AF Feldman, U Doschek, GA Behring, WE Phillips, KJH TI Electron temperature, emission measure, and X-ray flux in A2 to X2 X-ray class solar flares SO ASTROPHYSICAL JOURNAL LA English DT Article DE sun, flares; sun, X-rays ID DIELECTRONIC SATELLITE SPECTRA; HELIUM-LIKE IONS; ELEMENTAL ABUNDANCES; IRON; LINES AB In this paper we present a statistical analysis of soft X-ray flare class and emission measure as a function of electron temperature determined for the time of maximum flare X-ray flux. The study includes 868 flares of X-ray class A2 to X2. Our work shows that their properties are very different, although large and small flares as seen by the 1-8 Angstrom detector aboard the Geostationary! Operational Environmental Satellite (GOES) records have similar appearances. The peak temperature of intense (major) flares is much higher than the peak temperature of weak (minor) flares. This finding has important implications on the nature of the flare-heating mechanism. For example, if a flare is a collection of elementary bursts, the plasma properties of the elementary-bursts occurring during peak emission of large flares and small flares must be different. Using the relationship between electron temperature and emission measure in solar flares, we provide an estimate of the electron temperature during the peak emission of large stellar flares. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RUTHERFORD APPLETON LAB,DIV ASTROPHYS,DIDCOT OX11 0QX,OXON,ENGLAND. RP Feldman, U (reprint author), USN,RES LAB,EO HULBURT CTR SPACE RES,CODE 7608,WASHINGTON,DC 20375, USA. NR 18 TC 74 Z9 74 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD APR 1 PY 1996 VL 460 IS 2 BP 1034 EP 1041 DI 10.1086/177030 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UB530 UT WOS:A1996UB53000040 ER PT J AU Wingard, DM Feeks, EF Bower, EA Piepenbrink, RA Carlberg, MA AF Wingard, DM Feeks, EF Bower, EA Piepenbrink, RA Carlberg, MA TI A case of a naval aviator on quinidine for lone atrial fibrillation SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article ID FRAMINGHAM; TRIALS AB While neither atrial fibrillation (AF) nor the therapeutic use of quinidine represent medical contraindications for civil aviation in the United States, they have both been indications for permanent grounding in the U.S. armed forces. We report a case of a naval aviator who was found to be in asymptomatic AF while undergoing a routine annual flight physical. The patient was pharmacologically converted and maintained in normal sinus rhythm with quinidine. Following review of his case by a Special Board of Flight Surgeons, he was returned to limited flight status for dual controlled aircraft only while maintained prophylactically on quinidine to prevent the recurrence of AF. C1 SUNY HLTH SCI CTR,SYRACUSE,NY 13210. USN HOSP,DEPT INTERNAL MED,PENSACOLA,FL. USN AIR STN,TRAINING AIR WING 5,WHITING FIELD,MA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD APR PY 1996 VL 67 IS 4 BP 341 EP 343 PG 3 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA UB528 UT WOS:A1996UB52800008 PM 8900986 ER PT J AU Kark, JA Burr, PQ Wenger, CB Gastaldo, E Gardner, JW AF Kark, JA Burr, PQ Wenger, CB Gastaldo, E Gardner, JW TI Exertional heat illness in Marine Corps recruit training SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article ID STROKE AB Background: Exertional heat illness (EHI) is a recurring problem in military training resulting in loss of manpower and training effectiveness. A scientific approach to this problem requires quantitative analysis of factors related to its occurrence. Methods: Review of clinic and hospital records identified all cases of EHI occurring among 217,000 Marine Corps recruits (90% male, 80% age 18-20 yr) entering 12-week basic training at Parris Island, SC during 1982-1991. Results: There were 1454 cases, 89% males and 11% females; 11% of male and no female cases were hospitalized. The majority (88%) of cases occurred during May-September, with a peak rate of 2% of recruits in summer. Most of the cases occurred during the cooler early morning hours when recruits performed strenuous exercise. During 0700-0900 hours the rate of heat casualties increased substantially as the Wet Bulb Globe Temperature Index (WBGT) increased, beginning at levels as low as 65 degrees F. EHI rates increased 26- and 39-fold at WBGT 75-<80 degrees F (over baseline rates at <65 degrees F) for immediate and prior day exposures, respectively. Exposure to WBGT of 80+degrees F was infrequent (25%) among the early morning cases at the time of illness, while it was common (87%) on the day prior to illness, suggesting a lasting effect of heat exposure. Conclusions: Risk for EHI in military training increases markedly as WBGT levels rise above 65 degrees F; cases occur primarily with strenuous exercise (e.g., running); and heat stress exposure on prior days may be important. C1 UNIFORMED SERV UNIV HLTH SCI,DEPT PREVENT MED & BIOMETR,BETHESDA,MD 20814. HOWARD UNIV HOSP,WASHINGTON,DC. USA,ENVIRONM MED RES INST,NATICK,MA 01760. USN HOSP,BEAUFORT,SC. NR 33 TC 59 Z9 65 U1 0 U2 2 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD APR PY 1996 VL 67 IS 4 BP 354 EP 360 PG 7 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA UB528 UT WOS:A1996UB52800011 PM 8900989 ER PT J AU Karle, IL Banerjee, A Bhattacharjya, S Balaram, P AF Karle, IL Banerjee, A Bhattacharjya, S Balaram, P TI Solid state and solution conformations of a helical peptide with a central Gly-Gly segment SO BIOPOLYMERS LA English DT Article ID ALPHA-AMINOISOBUTYRIC-ACID; CIRCULAR-DICHROISM; AMINO-ACIDS; PROTEINS; CRYSTAL; RESIDUES; STEREOCHEMISTRY; OLIGOPEPTIDES; HEPTAPEPTIDE; FEATURES AB The influence of amino acids with contrasting conformational tendencies on the stereochemistry of oligopeptides has been investigated using an octapeptide Boc-Leu-Aib-Val-Gly-Gly-Leu-Aib-Val-OMe, which contains two helix-promoting Aib residues and a central helix-destabilizing Gly-Gly segment. Single crystal x-ray diffraction studies reveal that a 3(10)-helix a formed up to the penultimate Aib residue, at which point there is a helix reversal in the backbone, reminiscent of a C-terminal 6 --> 1 hydrogen bond. The curious feature in the crystal is the solvation of the possible 6 --> 1 bond by a Ch(3)OH molecule, where the OH is inserted between O(3) and N(8) and participates in hydrogen bonds with both. The cell parameters are as follows: space group P2(1)2(1)2(1), a = 10.649(4) Angstrom, b = 15.694(5) Angstrom, c = 30.181(8) Angstrom, R = 6.7% for 3427 data (\F-0\ > 3 sigma F) observed to 0.9 Angstrom. Nuclear magnetic resonance studies in CDCl3 using NH group solvent accessibility and nuclear Overhauser effects as probes are consistent with a 3(10)-helical conformation. In contrast, in (CD3)(2)SO, unfolding of the central segment results in a multiple beta-turn structure, with beta-turn conformations populated at residues 1-2, 3-4, and 6-7. CD studies in methanol-2,2,2-trifluoroethanol (TFE) mixtures also provide evidence for a solvent-dependent structural transition. Helical conformations are populated in TFE, while type II beta-turn structures are favored in methanol. (C) 1996 John Wiley & Sons, Inc. C1 INDIAN INST SCI,MOLEC BIOPHYS UNIT,BANGALORE 560012,KARNATAKA,INDIA. RP Karle, IL (reprint author), USN,RES LAB,STRUCT MATTER LAB,WASHINGTON,DC 20375, USA. RI Bhattacharjya, SURAJIT/A-2183-2011 FU NIGMS NIH HHS [GM-30902] NR 38 TC 44 Z9 44 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0006-3525 J9 BIOPOLYMERS JI Biopolymers PD APR PY 1996 VL 38 IS 4 BP 515 EP 526 DI 10.1002/(SICI)1097-0282(199604)38:4<515::AID-BIP7>3.3.CO;2-P PG 12 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA UA092 UT WOS:A1996UA09200008 PM 8867213 ER PT J AU Pauley, PM Baker, NL Barker, EH AF Pauley, PM Baker, NL Barker, EH TI An observational study of the ''Interstate 5'' dust storm case SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SYSTEM AB On 29 November 1991 a series of collisions involving 164 vehicles occurred on Interstate 5 in the San Joaquin Valley in California in a dust storm that reduced the visibility to near zero. The accompanying high surface winds are hypothesized to result from intense upper-tropospheric downward motion that led to the formation of a strong upper front and tropopause fold and that transported high momentum air downward to midlevels where boundary layer processes could then mix it to the surface. The objectives of the research presented in this paper are to document the event, to provide support for the hypothesis that both upper-level and boundary layer processes were important, and to determine the structure of the mesoscale circulations in this case for future use in evaluating the navy's mesoscale data assimilation system. The strong upper-level descent present in this case is consistent with what one would expect for jet streak and frontal circulations in combination with quasigeostrophic processes. During the period examined, upper-level data and analyses portray a strong upper-tropospheric jet streak with maximum winds initially in excess of 85 m s(-1) (approximate to 170 kt) that weakened as it propagated southward around the base of a long-wave trough. The jet streak was accompanied by a strong upper front and tropopause fold, both of which imply intense downward motion. The vertical motion field near the time of the accidents had two maxima-one that was associated with a combination of quasigeostrophic forcing and terrain-induced descent in the lee of the Sierra and one that was associated with the descending branch of the secondary circulation in the jet streak exit region and the cold advection by both the geostrophic wind and the ageostrophic wind in the upper front. The 700-hPa wind speed maximum over and west of the San Joaquin Valley overlapped with the latter maximum, supporting the hypothesized role of downward momentum transport. Given the significant 700-hPa wind speeds over the San Joaquin Valley during daytime hours on the day of the collisions, boundary layer mixing associated with solar heating of the earth's surface was then able to generate high surface winds. Once the high surface winds began, a dust storm was inevitable, since winter rains had not yet started and soil conditions were drier than usual in this sixth consecutive drought year. Surface observations from a variety of sources depict blowing dust and high surface winds at numerous locations in the San Joaquin Valley, the Mojave and other desert sites, and in the Los Angeles Basin and other south coast sites. High surface winds and low visibilities began in the late morning at desert and valley sites and lasted until just after sunset, consistent with the hypothesized heating-induced mixing. The 0000 UTC soundings in California portrayed an adiabatic layer from the surface to at least 750 hPa, also supporting the existence of mixing. On the other hand, the high winds in the Los Angeles Basin began near sunset in the wake of a propagating mesoscale trough that appeared to have formed in the lee of the mountains that separate the Los Angeles Basin from the San Joaquin Valley. C1 COMP SCI CORP,MONTEREY,CA. USN,RES LAB,MONTEREY,CA. RP Pauley, PM (reprint author), USN,POSTGRAD SCH,DEPT METEOROL,MONTEREY,CA 93943, USA. NR 31 TC 29 Z9 36 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD APR PY 1996 VL 77 IS 4 BP 693 EP 720 DI 10.1175/1520-0477(1996)077<0693:AOSOTD>2.0.CO;2 PG 28 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UG177 UT WOS:A1996UG17700004 ER PT J AU Ginger, KM Moran, JM Weinbeck, RS Geer, IW Snow, JT Smith, DR AF Ginger, KM Moran, JM Weinbeck, RS Geer, IW Snow, JT Smith, DR TI Project ATMOSPHERE - 1995 teacher enhancement programs SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB For the second consecutive summer, the American Meteorological Society (AMS) conducted four teacher and faculty enhancement workshops in the atmospheric sciences. Project ATMOSPHERE, the K-12 educational initiative of the AMS, conducted two workshops for teachers in the Atmospheric Education Resource Agent program and another workshop for master precollege teachers from across the nation. The AMS, with support from the National Science Foundation, held a fourth workshop for undergraduate faculty members from two- and four-year colleges who teach weather-related topics. These 1995 workshops provided educators at all levels with learning experiences on a variety of atmospheric topics and an introduction to operational and research activities of the meteorological community. C1 UNIV WISCONSIN,GREEN BAY,WI 54302. SUNY COLL BROCKPORT,BROCKPORT,NY 14420. UNIV OKLAHOMA,NORMAN,OK 73019. USN ACAD,ANNAPOLIS,MD 21402. RP Ginger, KM (reprint author), AMER METEOROL SOC,1701 K ST NW,SUITE 300,WASHINGTON,DC 20006, USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD APR PY 1996 VL 77 IS 4 BP 763 EP 769 DI 10.1175/1520-0477(1996)077<0763:EA>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UG177 UT WOS:A1996UG17700008 ER PT J AU Ferritto, JM AF Ferritto, JM TI Repeatability of microseism measurements in Port Hueneme case study SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID EARTHQUAKE; 1-SECOND; TREMORS AB Microseism measurements can assist in prediction of ground-motion amplification and microzonation. A series of array measurements were conducted in the Port Hueneme, California, area. The measurements were repeated, and the error of microseism measurements is discussed. From the seven individual trials, it was possible to show the convergence of microseism measurements and their repeatability. The series of array measurements of microseisms used both a soil and a rock reference site. The soil site was a site having a well-defined boring log. A comparison is made between results obtained using a rock and a soil reference site. It was found that qualitatively the general dimensionless shape of relative amplification contour plots was similar using both reference sites. Both reference sites showed the same regions as having higher amplification compared with other lower regions. RP Ferritto, JM (reprint author), USN,FACIL ENGN CTR,PORT HUENEME,CA 93043, USA. NR 26 TC 1 Z9 1 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD APR PY 1996 VL 86 IS 2 BP 428 EP 435 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UJ351 UT WOS:A1996UJ35100014 ER PT J AU Little, B Wagner, P AF Little, B Wagner, P TI An overview of microbiologically influenced corrosion of metals and alloys used in the storage of nuclear wastes SO CANADIAN JOURNAL OF MICROBIOLOGY LA English DT Review DE nuclear waste storage; microbiologically influenced corrosion; biofilms ID BACTERIA; SEDIMENT; SITES AB Microbiologically influenced corrosion has been documented for all metals and alloys currently in use or proposed for packaging nuclear wastes, with the possible exception of titanium. Selection of a material that will provide a reliable physical barrier to prevent leakage of radionuclides for 10(3)-10(6) years will depend on a thorough understanding of mechanisms for microbiologically influenced corrosion; the geological, microbiological, and chemical environments of storage sites; and their evolution over time. RP Little, B (reprint author), USN,RES LAB,BAY ST LOUIS,MS 39529, USA. NR 44 TC 21 Z9 22 U1 2 U2 11 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4166 J9 CAN J MICROBIOL JI Can. J. Microbiol. PD APR PY 1996 VL 42 IS 4 BP 367 EP 374 PG 8 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Immunology; Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Immunology; Microbiology GA UE280 UT WOS:A1996UE28000008 ER PT J AU Bhole, SD Fox, AG AF Bhole, SD Fox, AG TI Influence of GTA welding thermal cycles on HSLA-100 steel plate SO CANADIAN METALLURGICAL QUARTERLY LA English DT Article ID LOW-CARBON AB Autogenous gas-tungsten are (GTA) welds were performed on U.S. Navy HSLA-100 steel with heat inputs of 0.7, 1.1 and 2.2 kJ/mm. The absence of weld metal and underbead HAZ cracking illustrated the advantage of low carbon steel for both weld wire and base plate. The maximum microhardness values in the coarse grain HAZ next to the fusion line were found to be well below 375 HV, which is usually considered to be the hardness value above which severe hydrogen induced cold cracking can be observed in this type of steel. Optical, scanning and transmission electron microscopy studies of the HAZ microstructure were correlated with the continuous cooling transformation diagram for this steel, and good agreement between the observed and predicted microstructures was obtained. Unfortunately, the autogenous weld metal yield strength appeared to be somewhat lower than Navy specifications. It is therefore suggested that a more highly alloyed weld consumable than HSLA-100 be employed to maintain the weld metal yield strength at least equal to that of the base plate. Copyright (C) 1996 Canadian Institute of Mining and Metallurgy. C1 USN,POSTGRAD SCH,DEPT MECH ENGN,MAT SCI SECT,MONTEREY,CA 93943. RP Bhole, SD (reprint author), UNIV REGINA,REGINA,SK S4S 0A2,CANADA. NR 13 TC 1 Z9 2 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0008-4433 J9 CAN METALL QUART JI Can. Metall. Q. PD APR-JUN PY 1996 VL 35 IS 2 BP 151 EP 158 PG 8 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA UF428 UT WOS:A1996UF42800005 ER PT J AU Jamur, MC Oliver, C AF Jamur, MC Oliver, C TI Binding of antibody to the gamma subunit of FC(epsilon)RI in rat basophilic leukemia cells results in morphological changes without inducing histamine release SO CELL AND TISSUE RESEARCH LA English DT Article DE IgE receptor; gamma subunit; RBL-2H3 cells; immunocytochemistry; electron microscopy; rat (Sprague Dawley); mouse (Balb/c) ID IGE-RECEPTOR COMPLEXES; MONOCLONAL-ANTIBODIES; HIGH-AFFINITY; TRANSFECTED CELLS; MAST-CELLS; EXPRESSION AB The high affinity IgE receptor on mast cells and basophils is composed of 3 subunits, alpha, beta and gamma. A polyclonal antibody was raised in rabbits to a 13 amino acid synthetic peptide corresponding to the amino terminal portion of the gamma subunit. The antiserum was screened using Western blots of solubilized RBL-2H3 cells and I-125 goat anti-rabbit IgG, After purification of the serum on a protein G column, RBL-2H3 cells, mouse mast cells, and human basophils showed a doublet at 20 000 kDa. When I-125 labeled, saponin-permeabilized cells were immunoprecipitated with the anti-gamma antibody, all 3 subunits of the IgE receptor complex coprecipitated. Furthermore, binding of the antibody to the cell surface did not induce histamine release. By immunofluorescence of fixed cells, the receptor was evenly distributed in the RBL-2H3 cells. Although no capping was observed when the cells were incubated with the antibody prior to fixation, the antibody did stimulate endocytosis when it was bound to the cells at 25 degrees C or at 37 degrees C, but not at 4 degrees C. Binding of the antibody to the RBL-2H3 cells also induced cell spreading and ruffling of the plasma membrane, The results of this study indicate that the gamma subunit of the high affinity IgE receptor may play a role in signal transduction. C1 OFF NAVAL RES,ARLINGTON,VA 22217. FED UNIV PARANA,DEPT BIOL CELULAR,CURITIBA,PARANA,BRAZIL. RI Jamur, Maria Celia/L-5520-2016 OI Jamur, Maria Celia/0000-0001-7065-8543 NR 23 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0302-766X J9 CELL TISSUE RES JI Cell Tissue Res. PD APR PY 1996 VL 284 IS 1 BP 153 EP 159 DI 10.1007/s004410050575 PG 7 WC Cell Biology SC Cell Biology GA UD783 UT WOS:A1996UD78300015 PM 8601290 ER PT J AU Pike, JK Ho, T Wynne, KJ AF Pike, JK Ho, T Wynne, KJ TI Water-induced surface rearrangements of poly(dimethylsiloxane-urea-urethane) segmented block copolymers SO CHEMISTRY OF MATERIALS LA English DT Article ID INDUCED MACROMOLECULAR REARRANGEMENT; CONTACT-ANGLE HYSTERESIS; POLYMERIC SOLIDS; POLYSILOXANE; DYNAMICS AB An investigation of the surfaces of linear, segmented block copolymers of poly(dimethylsiloxane-urea-urethanes) by dynamic contact angle analysis is reported. The polymer films are immersed in water, the time-dependent advancing and receding contact angles are observed, and the contact angle hysteresis is reported. The initially hydrophobic polymer surfaces are observed to become more hydrophilic with long-term exposure to water. The advancing contact angles are relatively constant with immersion time; the receding contact angles decrease to some equilibrium value after a few days' exposure to water. It is proposed that the surfaces reorganize by a mechanism in which the hard block urethane-urea domains migrate through the soft block silicone to the polymer-water interface. The surface reorganization kinetics are discussed in terms of the effects of annealing as well as the average molecular weight of the soft block. C1 OFF NAVAL RES,PHYS SCI S&T DIV,ARLINGTON,VA 22217. USN,RES LAB,MAT CHEM BRANCH,WASHINGTON,DC 20375. RP Pike, JK (reprint author), VIRGINIA POLYTECH INST & STATE UNIV,DEPT CHEM,BLACKSBURG,VA 24061, USA. NR 34 TC 99 Z9 100 U1 5 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD APR PY 1996 VL 8 IS 4 BP 856 EP 860 DI 10.1021/cm9504596 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA UF852 UT WOS:A1996UF85200010 ER PT J AU Hyams, KC Yarbough, PO Gray, S Callahan, J Gotuzzo, E Gutierrez, J Vasquez, PB Hayes, CG Watts, DM AF Hyams, KC Yarbough, PO Gray, S Callahan, J Gotuzzo, E Gutierrez, J Vasquez, PB Hayes, CG Watts, DM TI Hepatitis E virus infection in Peru SO CLINICAL INFECTIOUS DISEASES LA English DT Article C1 GENELABS TECHNOL INC,REDWOOD CITY,CA. USN,MED RES INST DETACHMENT,WASHINGTON,DC. UNIV PERUANA CAYETANO HEREDIA,INST MED TROP ALEXANDER VON HUMBOLDT,LIMA,PERU. PERUVIAN NAVY,LIMA,PERU. RP Hyams, KC (reprint author), USN,INST MED RES,12300 WASHINGTON AVE,ROCKVILLE,MD 20852, USA. NR 8 TC 8 Z9 10 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 1058-4838 J9 CLIN INFECT DIS JI Clin. Infect. Dis. PD APR PY 1996 VL 22 IS 4 BP 719 EP 720 PG 2 WC Immunology; Infectious Diseases; Microbiology SC Immunology; Infectious Diseases; Microbiology GA UB853 UT WOS:A1996UB85300024 PM 8729219 ER PT J AU Khokhlov, AM Oran, ES Wheeler, JC AF Khokhlov, AM Oran, ES Wheeler, JC TI Scaling in buoyancy-driven turbulent premixed flames SO COMBUSTION AND FLAME LA English DT Article ID PROPAGATION AB A scaling law is proposed that gives the steady-state turbulent flame velocity in the regime where the flame is thin compared with the largest scale of the turbulence, diffusion effects are small compared to the fluid dynamics effects, and the turbulence is driven by the Rayleigh-Taylor instability in a gravitational field. This is the regime where the fluid dynamic effects dominate diffusion. These conditions exist in premixed hydrocarbon flames approaching the flammability limits and astrophysical objects, such as supernovae. It is proposed that laboratory combustion experiments could be used to calibrate the turbulence model for supernova explosions. C1 USN, RES LAB, LAB COMPUTAT PHYS, WASHINGTON, DC 20375 USA. RP Khokhlov, AM (reprint author), UNIV TEXAS, DEPT ASTRON, RLM 15308, AUSTIN, TX 78712 USA. NR 16 TC 19 Z9 19 U1 1 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD APR PY 1996 VL 105 IS 1-2 BP 28 EP 34 DI 10.1016/0010-2180(95)00157-3 PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA UC913 UT WOS:A1996UC91300003 ER PT J AU Lewis, T AF Lewis, T TI The next 10,000(2) years .1. SO COMPUTER LA English DT Article AB In the next 10,000(2) or 16 years, we'll not only cross the boundary into the next millennium but also witness major technological breakthroughs and breakdowns. In recent history, earthshaking changes have occurred every 150-200 years, with approximately 50-year boundary periods for the transition from the old to the new. According to the author, who also writes the Binary Critic department for Computer, we are nearing the end of a transition period. In the current transition, the breakthrough is in networking and software development, and the breakdown is in processor (VLSI) technology. Both forces will propel the high-tech world into a new model of computing by the year 2012. The new model will be based on a networked, global megacomputer that obeys the Gustafson-Barsis speedup law instead of the Amdahl law of parallelism. The next century's Information Superhighway will actually be a network of cable TV operators, not telephone companies. A new era of programming that eliminates traditional programming languages will arise and lead to a software economy-an electronic commerce dominated by software artisans. RP Lewis, T (reprint author), USN,POSTGRAD SCH,MONTEREY,CA 93940, USA. NR 7 TC 6 Z9 6 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 0018-9162 J9 COMPUTER JI Computer PD APR PY 1996 VL 29 IS 4 BP 64 EP & DI 10.1109/2.488302 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA UE437 UT WOS:A1996UE43700008 ER PT J AU Miller, AR Moskowitz, IS AF Miller, AR Moskowitz, IS TI Generalizations of the Carlton-Kimball distribution for a target's future location SO COMPUTERS & MATHEMATICS WITH APPLICATIONS LA English DT Article DE search theory; applications of hypergeometric functions AB This paper addresses the problem of searching for a target in the plane given only an initial position estimate and bounds on its speed and direction. Exact results are derived for determining the position density of the target's future location assuming constant linear motion. In particular, we derive a generalization of the Carlton-Kimball distribution. C1 USN,RES LAB,CTR HIGH ASSURANCE COMP SYST,WASHINGTON,DC 20375. NR 10 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0898-1221 J9 COMPUT MATH APPL JI Comput. Math. Appl. PD APR PY 1996 VL 31 IS 8 BP 61 EP 68 DI 10.1016/0898-1221(96)00031-4 PG 8 WC Mathematics, Applied SC Mathematics GA UD547 UT WOS:A1996UD54700007 ER PT J AU Ellis, JA Whitehill, BV Irick, C AF Ellis, JA Whitehill, BV Irick, C TI The effects of explanations and pictures on learning, retention, and transfer of a procedural assembly task SO CONTEMPORARY EDUCATIONAL PSYCHOLOGY LA English DT Article ID ILLUSTRATIONS; TEXT AB Two experiments investigated the effects of qualitative explanations and pictures on learning, retention, and transfer of a procedural assembly task. Results showed that (1) functional explanations are more effective than structural explanations in learning and remembering an assembly task; however, their effects are diminished when learning subsequent similar tasks, (2) providing pictures facilitates learning but does not help performance once the task has been learned to criterion, and (3) previous experience in a task domain results in positive transfer to new tasks in the same domain. (C) 1996 Academic Press, Inc. C1 BOULDER OAKS ELEMENTARY SCH,ALPINE,CA. RP Ellis, JA (reprint author), USN,CTR PERSONNEL RES & DEV,CODE 13,53335 RYNE RD,SAN DIEGO,CA 92152, USA. NR 34 TC 8 Z9 8 U1 1 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0361-476X J9 CONTEMP EDUC PSYCHOL JI Contemp. Educ. Psychol. PD APR PY 1996 VL 21 IS 2 BP 129 EP 148 DI 10.1006/ceps.1996.0012 PG 20 WC Psychology, Educational SC Psychology GA UL991 UT WOS:A1996UL99100002 ER PT J AU McDaniel, DH Ash, K Zukowski, M AF McDaniel, DH Ash, K Zukowski, M TI Treatment of stretch marks with the 585-nm flashmap-pumped pulsed dye laser SO DERMATOLOGIC SURGERY LA English DT Article ID STRIAE-DISTENSAE; SKIN; TRETINOIN AB BACKGROUND. Striae, or stretch marks, are very common skin disorders that do not impair bodily function, but are of considerable cosmetic concern to many patients. Traditionally, treatment options have been very limited. This study examines the results of treating striae using the 585-nm pulsed dye laser. Stimulation of a variety of wound healing processes has been attributed to low energy laser therapy. Clinically, improvement of hypertrophic and erythematous scars with the 585-nm pulsed dye laser at energy densities of 6-7 J/cm(2) is well established. Since striae are dermal sears, evaluation of this same therapy to treat striae was undertaken. OBJECTIVE. TO evaluate the effectiveness of the 585-nm flashlamp-pumped pulse dye laser in treating cutaneous striae. METHODS. Thirty-nine striae were treated with four treatment protocols. These treated striae were compared with untreated striae controls in the same patient. The patients ages ranged from 23 to 52 years, with an average age of 36 years. The average age of-the treated striae prior to initial treatment was 14 years (range, 8 months to 32 years). Treatment parameters included spot sizes of 7 and 10 mm and fluences of 2.0, 2.5, 3.0, and 4.0 J/cm(2). Response to therapy was evaluated through clinical grading, sequential photography, and optical profilometry at a blinded laboratory. Skin biopsies were also examined with light microscopy from two of the 39 striae that were treated. RESULTS. Subjectively, striae appeared to return toward the appearance of normal skin With all protocols. However, the protocol with 10-mm spot size using 3.0 J/cm(2) fluence improved the appearance of striae better than the other treatment protocols. Objectively, shadow profilometry revealed that all treatment protocols reduced skin shadowing in striae. This result corresponds with surface patterns of striae returning to that closely resembling adjacent normal skin surface patterns. Histologically, using hematoxylin and eosin stains as well as elastin strains, striae treated with a low fluence pulsed dye laser treatment protocol regained normal appearing elastin content when compared with normal (non-striae) skin adjacent to the treated striae. CONCLUSION. Treatment with the 585-nm pulsed dye laser at low energy densities was shown to improve the appearance of striae. Apparent increased dermal elastin teas also observed 8 weeks posttherapy and possibly contributed to the improvement seen in the study patients. C1 EASTERN VIRGINIA MED SCH,LASER CTR VIRGINIA,VIRGINIA BEACH,VA. EASTERN VIRGINIA MED SCH,DEPT DERMATOL,VIRGINIA BEACH,VA. EASTERN VIRGINIA MED SCH,DEPT PLAST SURG,VIRGINIA BEACH,VA. USN,MED CTR,DEPT GEN SURG,PORTSMOUTH,VA. USN,MED CTR,DEPT PLAST & RECONSTRUCT SURG,PORTSMOUTH,VA. NR 16 TC 80 Z9 81 U1 0 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1076-0512 J9 DERMATOL SURG JI Dermatol. Surg. PD APR PY 1996 VL 22 IS 4 BP 332 EP 337 PG 6 WC Dermatology; Surgery SC Dermatology; Surgery GA UK181 UT WOS:A1996UK18100003 PM 8624657 ER PT J AU Russell, AE Rubasingham, L Hagans, PL Ballinger, TH AF Russell, AE Rubasingham, L Hagans, PL Ballinger, TH TI Cell and optics design for in situ far-infrared spectroscopy of electrode surfaces SO ELECTROCHIMICA ACTA LA English DT Article DE far-infrared; synchrotron radiation; water absorption; electrochemical cell; acetonitrile ID SYNCHROTRON-RADIATION; CONSTANTS; WATER AB In situ far-infrared studies of the electrode/electrolyte interface using synchrotron radiation as the far-infrared source promise to provide new insights into interfacial structure. However, several precautions must be taken when conducting such experiments in order to produce reliable and reproducible results. These precautions are discussed and an experimental design is presented. C1 USN, RES LAB, WASHINGTON, DC 20375 USA. RP Russell, AE (reprint author), UNIV NEWCASTLE UPON TYNE, DEPT CHEM, BEDSON BLDG, NEWCASTLE UPON TYNE NE1 7RU, TYNE & WEAR, ENGLAND. RI Russell, Andrea/B-8114-2009; Russell, Andrea/A-9625-2012 NR 12 TC 9 Z9 9 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-4686 J9 ELECTROCHIM ACTA JI Electrochim. Acta PD APR PY 1996 VL 41 IS 5 BP 637 EP 640 DI 10.1016/0013-4686(95)00351-7 PG 4 WC Electrochemistry SC Electrochemistry GA TY413 UT WOS:A1996TY41300004 ER PT J AU Olson, PE Hames, CS Benenson, AS Genovese, EN AF Olson, PE Hames, CS Benenson, AS Genovese, EN TI The thucydides syndrome: Ebola deja vu? (Or Ebola reemergent?) SO EMERGING INFECTIOUS DISEASES LA English DT Letter C1 SAN DIEGO STATE UNIV,SAN DIEGO,CA 92182. RP Olson, PE (reprint author), USN,BALBOA HOSP,SAN DIEGO,CA 92152, USA. NR 9 TC 14 Z9 15 U1 0 U2 1 PU CENTER DISEASE CONTROL PI ATLANTA PA ATLANTA, GA 30333 SN 1080-6040 J9 EMERG INFECT DIS JI Emerg. Infect. Dis PD APR-JUN PY 1996 VL 2 IS 2 BP 155 EP 156 PG 2 WC Immunology; Infectious Diseases SC Immunology; Infectious Diseases GA UM787 UT WOS:A1996UM78700020 PM 8964060 ER PT J AU Lewis, DW Middlebrook, MT Mehallick, L Rauch, TM Deline, C Thomas, EF AF Lewis, DW Middlebrook, MT Mehallick, L Rauch, TM Deline, C Thomas, EF TI Pediatric headaches: What do the children want? SO HEADACHE LA English DT Article DE headache; migraine; child; art therapy ID MIGRAINE; CHILDHOOD; PAIN AB One hundred consecutive children (aged 3 to 17 years), drawn from primary care pediatric clinics, with a greater than 3-month history of headaches completed surveys to determine the type and associated features of their headache and to query their reasons for wanting to see a physician. Additionally, the children were asked to draw pictures of how they felt when they had a headache to assess their nonverbal perceptions. Over 90% of the headaches were migrainous (65% common. 23% classic, 5% basilar). The children wanted three answers from the physician: what was the cause of their headache, what would make it better, and reassurrance that they had no life-threatening illness. Furthermore, 33% of the children's illustrations disclosed depressive features of helplessness, frustration. and anger. Over 20% of the adolescents depicted themselves as dead, dying, or about to be killed by their headache. C1 USN HOSP,DEPT PEDIAT,PORTSMOUTH,VA. CHILDRENS HOSP KINGS DAUGHTERS,NEURODEV CTR,EASTERN VIRGINIA MED SCH,DIV PEDIAT NEUROL,NORFOLK,VA 23510. CHILDRENS HOSP KINGS DAUGHTERS,EASTERN VIRGINIA MED SCH,DEPT NEUROL,NORFOLK,VA. CHILDRENS HOSP KINGS DAUGHTERS,EASTERN VIRGINIA MED SCH,GRAD ART THERAPY PROGRAM,NORFOLK,VA. NR 32 TC 41 Z9 41 U1 1 U2 2 PU AMER ASSOC STUDY HEADACHE PI WOODBURY PA 875 KINGS HIGHWAY, STE 200, WOODBURY, NJ 08096 SN 0017-8748 J9 HEADACHE JI Headache PD APR PY 1996 VL 36 IS 4 BP 224 EP 230 DI 10.1046/j.1526-4610.1996.3604224.x PG 7 WC Clinical Neurology SC Neurosciences & Neurology GA UJ448 UT WOS:A1996UJ44800002 PM 8675427 ER PT J AU Strobel, DF Zhu, X Summers, ME Stevens, MH AF Strobel, DF Zhu, X Summers, ME Stevens, MH TI On the vertical thermal structure of Pluto's atmosphere SO ICARUS LA English DT Article ID CURTIS MATRIX INTERPOLATION; PLANETARY-ATMOSPHERES; OCCULTATION DATA; ENERGY-TRANSFER; COOLING RATES; TRITON; METHANE; MODELS; BAND; SURFACE AB A radiative-conductive model for the vertical thermal structure of Pluto's atmosphere is developed with a non-LTE treatment of solar heating in the CH4 3.3 mu m and 2.3 mu m bands, non-LTE radiative exchange and cooling in the CH4 7.6 mu m band, and LTE cooling by CO rotational line emission, The model includes the effects of opacity and vibrational energy transfer in the CH4 molecule, Partial thermalization of absorbed solar radiation in the CH4 3.3 and 2.3 mu m bands by rapid vibrational energy transfer from the stretch modes to the bending modes generates high altitude heating at sub-microbar pressures. Heating in the 2.3 mu m bands exceeds heating in 3.3 mu m bands by approximately a factor of 6 and occurs predominantly at microbar pressures to generate steep temperature gradients similar to 10-20 K km(-1) for p > 2 mu bar when the surface or tropopause pressure is similar to 3 mu bar and the CH4 mixing ratio is a constant 3%, This calculated structure may account for the ''knee'' in the stellar occultation lightcurve. The vertical temperature structure in the first 100 km above the surface is similar for atmospheres with Ar, CO, and N-2 individually as the major constituent. If a steep temperature gradient similar to 20 K km(-1) is required near the surface or above the tropopause, then the preferred major constituent is Ar with 3% CH4 mixing ratio to attain a calculated ratio of TIM (3.5 K amu(-1)) in agreement with inferred values from stellar occultation data. However, pure Ar and N-2 ices at the same temperature yield an Ar vapor pressure of only similar to 0.04 times the N-2 vapor pressure. Alternative scenarios are discussed that may yield acceptable fits with N-2 as the dominant constituent. One possibility is a 3 mu bar N-2 atmosphere with 0.3% CH4 that has 106 K isothermal region 3.8 K amu(-1)) and similar to 8 K amu(-1) surface/tropopause temperature gradient, Another possibility would be a higher surface pressure similar to 10 mu bar with a scattering haze for p > 2 mu bar. Our model with appropriate adjustments in the CH4 density profile to Triton's inferred profile yields a temperature profile consistent with the UVS solar occultation data (Krasnopolsky, V, A., B. R, Sandel, and F. Herbert 1992, J. Geophys. Res. 98, 3065-3078.) and ground-based stellar occultation data (Elliot, J. L., E, W, Dunham, and C, B, Olkin 1993. Bull. Am. Astron. Sec. 25, 1106.). (C) 1996 Academic Press,Inc. C1 USN, RES LAB, EO HULBURT CTR SPACE RES, WASHINGTON, DC 20375 USA. RP Strobel, DF (reprint author), JOHNS HOPKINS UNIV, DEPT EARTH & PLANETARY SCI, BALTIMORE, MD 21218 USA. RI Zhu, Xun/C-2097-2016; OI Zhu, Xun/0000-0001-7860-6430; Stevens, Michael/0000-0003-1082-8955 NR 53 TC 62 Z9 62 U1 0 U2 5 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD APR PY 1996 VL 120 IS 2 BP 266 EP 289 DI 10.1006/icar.1996.0050 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UH038 UT WOS:A1996UH03800002 ER PT J AU Summers, ME Strobel, DF AF Summers, ME Strobel, DF TI Photochemistry and vertical transport in Io's atmosphere and ionosphere SO ICARUS LA English DT Article ID EARTHS UPPER-ATMOSPHERE; PLANETARY-ATMOSPHERES; SO2 ATMOSPHERE; VOYAGER-1 ENCOUNTER; MOLECULE REACTIONS; SPECTRAL EVIDENCE; COMETARY COMAE; CROSS-SECTIONS; SOLAR MAXIMUM; PLASMA TORUS AB We present an updated model for the photochemistry of Io's atmosphere and ionosphere and use this model to investigate the sensitivity of the chemical structure to vertical transport rates. SO2 is assumed to be the dominant atmospheric gas, with minor molecular sodium species such as Na2S or Na2O released by sputtering or venting from the surface. Photochemical products include SO, O-2, S, O, Na, NaO, NaS, and Na-2. We consider both ''thick'' and ''thin'' SO2 atmospheres that encompass the range allowed by recent I-IST and millimeter-wave observations, and evaluate the possibility that O-2 and/or SO may be significant minor dayside constituents and therefore likely dominant nightside gases. The fast reaction between S and O-2 limits the column abundance of O-2 to similar to 10(4) less than that calculated by Kumar (J. Geophys. Res. 87, 1677-1684, 1982; 89(A9), 7399-7406, 1984) for a pure sulfur/oxygen atmosphere. If a significant source of NaO2 or Na2O were supplied by the surface and mixed rapidly upward, then oxygen liberated in the chemical reactions which also liberate free Na would provide an additional source of O-2. Fast eddy mixing will enhance the transport of molecular sodium species to the exobase, in addition to increasing the vertical transport rate of ions. Ions produced in the atmosphere will be accelerated by the reduced corotation electric field penetrating the atmosphere. These ions experience collisions with the neutral gas, leading to enhanced vertical ion diffusion. The dominant ion, Na+, is lost primarily by charge exchange with Na2O and/or Na2S in the lower atmosphere and by diffusion through the ionopause in the upper atmosphere. The atmospheric column abundance of SO, O-2, and the upper atmosphere escape rates of Na, S, O, and molecular sodium species are all strong functions of the eddy mixing rate. Most atmospheric escape, including that of molecular sodium species, probably occurs from the low density ''background'' SO2 atmosphere, while a localized high density ''volcanic'' SO2 atmosphere can yield an ionosphere consistent with that detected by the Pioneer 10 spacecraft. (C) 1996 Academic Press, Inc. C1 JOHNS HOPKINS UNIV,CTR ASTROPHYS SCI,DEPT EARTH & PLANETARY SCI,BALTIMORE,MD 21218. JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. RP Summers, ME (reprint author), USN,RES LAB,EO HULBURT CTR SPACE RES,WASHINGTON,DC 20375, USA. NR 98 TC 60 Z9 60 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD APR PY 1996 VL 120 IS 2 BP 290 EP 316 DI 10.1006/icar.1996.0051 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UH038 UT WOS:A1996UH03800003 ER PT J AU Thompson, CH Love, RH AF Thompson, CH Love, RH TI Determination of fish size distributions and areal densities using broadband low-frequency measurements SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT ICES International Symposium on Fisheries and Plankton Acoustics CY JUN 12-16, 1995 CL MARINE LAB, ABERDEEN, SCOTLAND SP Int Council Explorat Sea, Inst Acoust, Acoust Soc Amer, Soc Francaise Acoust HO MARINE LAB DE low-frequency scattering; scattering from fish; swimbladder resonance ID SCATTERING AB Broadband low-frequency measurements have been used in conjunction with a fish swimbladder scattering model to determine size distributions and areal densities of well-known populations of dispersed fishes. The method has also been used to identify and estimate the abundance of deep-dwelling fishes that are generally beyond the range of high-frequency echo-sounders. It can also be used to examine swimbladder behavior. Results on five fish species in three widespread locations are presented to demonstrate the capabilities of the method. (C) 1996 International Council for the Exploraiton of the Sea RP Thompson, CH (reprint author), USN,RES LAB,BAY ST LOUIS,MS 39529, USA. NR 11 TC 19 Z9 20 U1 0 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD APR PY 1996 VL 53 IS 2 BP 197 EP 201 DI 10.1006/jmsc.1996.0022 PG 5 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA UJ679 UT WOS:A1996UJ67900011 ER PT J AU Liguori, F Copley, RA AF Liguori, F Copley, RA TI Re-hosting test program sets effectively and affordably SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB This paper describes an innovative process for re-hosting test program sets from an existing tester for which they were originally prepared to operate on another tester. The process greatly reduces the time and cost usually required for offloading a test program set while retaining most of the original design and interface hardware. C1 TPS ASSOCIATES INC,LAKEHURST,NJ 08733. RP Liguori, F (reprint author), USN,AIR WARFARE CTR,DIV AIRCRAFT,LAKEHURST,NJ 08733, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD APR PY 1996 VL 11 IS 4 BP 34 EP 37 DI 10.1109/62.490222 PG 4 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA UE972 UT WOS:A1996UE97200011 ER PT J AU Mouret, I Calvel, P Allenspach, M Titus, JL Wheatley, CF LaBel, KA Calvet, MC Schrimpf, RD Galloway, KF AF Mouret, I Calvel, P Allenspach, M Titus, JL Wheatley, CF LaBel, KA Calvet, MC Schrimpf, RD Galloway, KF TI Measurement of a cross-section for single-event gate rupture in power MOSFET's SO IEEE ELECTRON DEVICE LETTERS LA English DT Article AB The heavy-ion fluence required to induce Single-Event Gate Rupture (SEGR) in power MOSFET's is measured as a function of the drain bias, V-DS, and as a function of the gate bias, V-GS These experiments reveal the abrupt nature of the SEGR-voltage threshold, In addition, the concepts of cross-section, threshold, and saturation in the SEGR phenomenon are introduced, This experimental technique provides a convenient method to quantify heavy-ion effects in power MOSFET's. C1 AEROSPITIALE,F-71833 LES MUREAUX,FRANCE. ALCATEL ESPACE,F-31037 TOULOUSE,FRANCE. USN,CTR SURFACE WARFARE,CRANE,IN 47522. RR2,DRUMS,PA 18222. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP Mouret, I (reprint author), UNIV ARIZONA,TUCSON,AZ 85721, USA. RI Schrimpf, Ronald/L-5549-2013 OI Schrimpf, Ronald/0000-0001-7419-2701 NR 12 TC 16 Z9 16 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0741-3106 J9 IEEE ELECTR DEVICE L JI IEEE Electron Device Lett. PD APR PY 1996 VL 17 IS 4 BP 163 EP 165 DI 10.1109/55.485161 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA UC510 UT WOS:A1996UC51000003 ER PT J AU Leinhos, HA AF Leinhos, HA TI Capacity calculations for rapidly fading communications channels SO IEEE JOURNAL OF OCEANIC ENGINEERING LA English DT Article AB This paper derives an upper bound for the Shannon channel capacity-cost function for a class of randomly time-varying channels under an average power constraint. The channels considered can be characterized by a series of uncorrelated parallel diversity channels with Gaussian-distributed random gain and additive white Gaussian noise parameters. The resulting expression for the single-channel case clearly shows that such channels have finite capacity even when the source power is unconstrained. Extensions are made to the multiple-diversity-channel case with a modified ''water-filling'' problem resulting. RP Leinhos, HA (reprint author), USN,UNDERSEA WARFARE CTR DIV,LAUNCHER & MISSILE SYST DEPT,NEWPORT,RI 02841, USA. NR 7 TC 9 Z9 9 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0364-9059 J9 IEEE J OCEANIC ENG JI IEEE J. Ocean. Eng. PD APR PY 1996 VL 21 IS 2 BP 137 EP 142 DI 10.1109/48.486788 PG 6 WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical & Electronic; Oceanography SC Engineering; Oceanography GA UJ107 UT WOS:A1996UJ10700002 ER PT J AU Tremblay, RJ Lytle, DW AF Tremblay, RJ Lytle, DW TI Development and analysis of echo classification using time delays SO IEEE JOURNAL OF OCEANIC ENGINEERING LA English DT Article ID PROCESSING TECHNIQUES; SIGNAL AB The results from an investigation of an analytically based method for determining the performance of echo classifiers are presented here. In particular, the problem of classifying echo waveforms reflected from objects that are composed of multiple scatterers is considered. The time delays between the multiple echo returns from the individual scattering centers that characterize an object are investigated as features. A generic stochastic point scatterer model is developed for representing the classes of reflecting objects which are of interest. The model allows for uncertainty in prior knowledge about the exact relative location of the individual component scatterers or uncertainty in the delay measurements. A classifier decision algorithm, in the form of a general optimum Bayesian binary classification decision rule suitable for a large variety of classification problems, is derived for the case when the orientation of the reflecting object is known. The case of unknown aspect angle is addressed through the numerical implementation and analysis of two classifiers. The associated performance for all three classifiers is obtained in terms of the probability of error and tied to standard sonar equation parameters. Example binary classification problems are presented and analyzed and some general observations made. A pragmatic framework is established within which complex echo classification issues can be further examined. C1 UNIV WASHINGTON,SEATTLE,WA 98195. RP Tremblay, RJ (reprint author), USN,UNDERSEA WARFARE CTR,NEW LONDON,CT 06320, USA. NR 23 TC 2 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0364-9059 J9 IEEE J OCEANIC ENG JI IEEE J. Ocean. Eng. PD APR PY 1996 VL 21 IS 2 BP 205 EP 215 DI 10.1109/48.486795 PG 11 WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical & Electronic; Oceanography SC Engineering; Oceanography GA UJ107 UT WOS:A1996UJ10700009 ER PT J AU Park, JC Kennedy, RM AF Park, JC Kennedy, RM TI Remote sensing of ocean sound speed profiles by a perceptron neural network SO IEEE JOURNAL OF OCEANIC ENGINEERING LA English DT Article ID FIELD AB A method is developed to estimate ocean sound speed profiles through synthesis of remotely measured environmental data and historical statistics of sound speed obtained at the remotely sensed location. Sound speed profiles are represented by an expansion of empirical orthogonal functions (EOF) of the historical sound speed variation, while the remotely sensed environmental data provide real-time information to determine the expansion coefficients. Environmental inputs are limited to sea surface temperature available from satellite infrared sensors, acoustic time-of-flight and ocean bottom temperature measurable from bottom mounted acoustic and thermal transducers. A multilayer perceptron neural network is implemented to learn the functional transformation from the measured environmental input to the desired EOF coefficient output on a set of representative sound speed profiles. Sea surface temperature; time-of-year, and time-of-flight from the acoustic multipath that maximally samples the vertical sound speed are found to be the dominant inputs. The trained network is computationally efficient and produces estimates for untrained environmental inputs with a mean error of 1.1-4.4 m/s. C1 USN,UNDERSES WARFARE CTR,AUTEC DETACHMENT,W PALM BEACH,FL 33401. NR 15 TC 4 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0364-9059 J9 IEEE J OCEANIC ENG JI IEEE J. Ocean. Eng. PD APR PY 1996 VL 21 IS 2 BP 216 EP 224 DI 10.1109/48.486796 PG 9 WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical & Electronic; Oceanography SC Engineering; Oceanography GA UJ107 UT WOS:A1996UJ10700010 ER PT J AU Gaunaurd, GC Huang, H AF Gaunaurd, GC Huang, H TI Acoustic scattering by an air bubble near the sea surface - Reply SO IEEE JOURNAL OF OCEANIC ENGINEERING LA English DT Article C1 USN,CTR SURFACE WARFARE,INDIAN HEAD DIV,SILVER SPRING,MD 20903. RP Gaunaurd, GC (reprint author), USN,CTR SURFACE WARFARE,CARDEROCK DIV,BETHESDA,MD 20084, USA. NR 1 TC 2 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0364-9059 J9 IEEE J OCEANIC ENG JI IEEE J. Ocean. Eng. PD APR PY 1996 VL 21 IS 2 BP 233 EP 233 DI 10.1109/JOE.1996.486799 PG 1 WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical & Electronic; Oceanography SC Engineering; Oceanography GA UJ107 UT WOS:A1996UJ10700013 ER PT J AU Strasberg, M AF Strasberg, M TI Acoustic scattering by an air bubble near the sea surface - Comment SO IEEE JOURNAL OF OCEANIC ENGINEERING LA English DT Article RP Strasberg, M (reprint author), USN,SURFACE WARFARE CTR,CARDEROCK DIV,BETHESDA,MD 20084, USA. NR 2 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0364-9059 J9 IEEE J OCEANIC ENG JI IEEE J. Ocean. Eng. PD APR PY 1996 VL 21 IS 2 BP 233 EP 233 DI 10.1109/48.486798 PG 1 WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical & Electronic; Oceanography SC Engineering; Oceanography GA UJ107 UT WOS:A1996UJ10700012 ER PT J AU Bowman, SR Shaw, LB Feldman, BJ Ganem, J AF Bowman, SR Shaw, LB Feldman, BJ Ganem, J TI A 7-mu m praseodymium-based solid-state laser SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article AB We report the first demonstration of laser emission from the F-3(3) to F-3(2) transition in the rare earth praseodymium. This new 7-mu m solid-state laser operates with an optical efficiency of 2.3% at 293 K and 10% at 150 K using an upconversion pumping mechanism, A discussion of the dynamics in this new laser material is included. C1 LOYOLA COLL,DEPT PHYS,BALTIMORE,MD 21210. RP Bowman, SR (reprint author), USN,RES LAB,LASER PHYS BRANCH,CODE 5640,WASHINGTON,DC 20375, USA. NR 7 TC 86 Z9 89 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD APR PY 1996 VL 32 IS 4 BP 646 EP 649 DI 10.1109/3.488838 PG 4 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA UE484 UT WOS:A1996UE48400009 ER PT J AU Dillard, RA Dillard, GM AF Dillard, RA Dillard, GM TI Likelihood-ratio detection of frequency-hopped signals SO IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS LA English DT Article ID SPREAD-SPECTRUM SIGNALS AB The optimum system for intercepting frequency-hopped signals uses a channelized receiver and a likelihood-ratio test (LRT). Previous results on the performance of the optimum system have been based on Gaussian assumptions, which are generally valid for transmissions having large time-bandwidth areas. Results, obtained by Monte Carlo simulation, for relatively small time-bandwidth transmissions are given here. The signal model is a simple one known as ''pure frequency hopping.'' Comparisons with the LRT show that energy detection loss increases when the time-bandwidth product of the transmission is increased by increasing the number of frequencies, even when the number of pulses is also increased. The loss decreases when only the number of pulses is increased. Over the parameter range observed, binary detection loss tends to increase with the number of pulses and decrease with the number of frequencies. Results are included for a moving-window version of the LRT. A parameter of the LRT is the signal-to-noise ratio (SNR). The effect of using a design value not equal to the true SNR is shown. C1 USN,COMMAND CONTROL & OCEAN SURVEILLANCE CTR,RES DEV TEST & EVALUAT DIV,SAN DIEGO,CA 92152. NR 7 TC 8 Z9 12 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9251 J9 IEEE T AERO ELEC SYS JI IEEE Trans. Aerosp. Electron. Syst. PD APR PY 1996 VL 32 IS 2 BP 543 EP 553 DI 10.1109/7.489499 PG 11 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA UG109 UT WOS:A1996UG10900005 ER PT J AU Rogers, LT AF Rogers, LT TI Effects of the variability of atmospheric refractivity on propagation estimates SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article AB The temporal and spatial sampling requirements of atmospheric refractivity used to calculate electromagnetic (EM) propagation effects (propagation factor, equivalently path loss, etc,) is currently a subject of debate, Results are presented from a propagation experiment designed to address these questions. The objective in propagation estimation is assumed to be the minimization of the error of propagation estimates over the entire time interval for which individual estimates are used, It is found that the minimum error of propagation estimates over the interval of their use can be calculated from radio measurements, The error of propagation estimates calculated from horizontally homogeneous refractive structures is compared to the minimum error. It is found that for beyond-line-of-sight overwater Ehl propagation factor calculations at VHF and UHF in the southern California coastal region, the assumption of horizontal homogeneity leads to little more error than the described minimum error, It is also found that estimates based upon range-dependent refractive structures will provide substantially less error than estimates based upon homogeneous refractive structures only if they are sampled at intervals of two hours or less. C1 OCEAN SURVEILLANCE CTR,RES DEV TEST & EVALUAT DIV,SAN DIEGO,CA 92106. RP Rogers, LT (reprint author), USN,COMMAND CONTROL,DIV OCEANOG & ATMOSPHER SCI,SAN DIEGO,CA 92106, USA. NR 10 TC 26 Z9 26 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD APR PY 1996 VL 44 IS 4 BP 460 EP 465 DI 10.1109/8.489297 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA UD858 UT WOS:A1996UD85800005 ER PT J AU Nguyen, KT Park, GS Choi, JJ Park, SY Parker, RK AF Nguyen, KT Park, GS Choi, JJ Park, SY Parker, RK TI Effects of beam velocity spread on two-stage tapered gyro-TWT amplifier SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article AB The recent successful operation of a two-stage K-a-band gyro-TWT amplifier at the Naval Research Laboratory has demonstrated its viability as a source of broadband high-power millimeter waves, However, it has been observed experimentally that sharp gain reductions occur at certain frequencies, In this paper, an analytical theory is presented which describes the effect of electron beam quality on the device's instantaneous bandwidth, It is shown that these observed gain dips are due to electron phase-mixing, resulting from finite beam velocity spreads, in the frequency-dependent sever, In addition, the theory demonstrates that the velocity-spread induced dips can be shifted or reduced by adjusting the magnetic field profile, circuit length, and beam axial velocity, consistent with experimental observations. C1 OMEGA P INC,NEW HAVEN,CT 06520. SCI APPLICAT INT CORP,MCLEAN,VA 22102. POHANG INST SCI & TECHNOL,DEPT PHYS,POHANG,SOUTH KOREA. USN,RES LAB,WASHINGTON,DC 20375. RP Nguyen, KT (reprint author), KN RES,SILVER SPRING,MD 20906, USA. RI Park, Gunsik/A-1415-2014 NR 8 TC 6 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD APR PY 1996 VL 43 IS 4 BP 655 EP 660 DI 10.1109/16.485549 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA UC511 UT WOS:A1996UC51100020 ER PT J AU Hopkinson, GR Dale, CJ Marshall, PW AF Hopkinson, GR Dale, CJ Marshall, PW TI Proton effects in charge-coupled devices SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID INDUCED DISPLACEMENT DAMAGE; SILICON DEVICES; DARK CURRENT; RADIATION; SPACE; CCDS; TEMPERATURE; DIFFUSION; EXTREMES; ARRAYS AB Basic mechanisms and ground-test data for radiation effects in solid-state imagers are reviewed, with a special emphasis on proton-induced effects on silicon charge-coupled devices (CCD's). For the proton fluxes encountered in the space environment, both transient ionization and displacement damage effects arise from single-particle interactions. In the former case, individual proton tracks will be seen; in the latter, dark-current spikes (or hot pixels) and trapping states that cause degradation in charge-transfer efficiency will be observed. Proton-induced displacement damage effects on dark current and charge transfer are considered in detail, and the practical implications for shielding, device hardening, and ground testing are discussed. C1 USN, RES LAB, WASHINGTON, DC 20375 USA. RP SIRA INST LTD, CHISLEHURST BR7 5EH, KENT, ENGLAND. NR 76 TC 110 Z9 122 U1 2 U2 17 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 1996 VL 43 IS 2 BP 614 EP 627 DI 10.1109/23.490905 PN 1 PG 14 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA UJ077 UT WOS:A1996UJ07700024 ER PT J AU McMorrow, D Weatherford, TR Buchner, S Knudson, AR Melinger, JS Tran, LH Campbell, AB AF McMorrow, D Weatherford, TR Buchner, S Knudson, AR Melinger, JS Tran, LH Campbell, AB TI Single-event phenomena in GaAs devices and circuits SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID INDUCED CHARGE COLLECTION; CURRENT TRANSIENTS; MESFETS; SEU; BIPOLAR; REDUCTION; UPSET; SRAMS; FETS; VULNERABILITY AB The single-event upset (SEU) characteristics of GaAs devices and circuits are reviewed. GaAs FET-based integrated circuits (IC's) are susceptible to upsets from both cosmic-ray heavy ions and protons trapped in the Earth's radiation belts. The origin of the SEU sensitivity of GaAs IC's is discussed in terms of both device-level and circuit-level considerations. At the device level, efficient charge-enhancement mechanisms through which more charge can be collected than is deposited by the ion have a significant negative impact on the SEU characteristics of GaAs IC's. At the circuit level, different GaAs digital logic topologies exhibit different levels of sensitivity to SEU because of variations in parameters, including logic levels, capacitances, and the degree of gate or peripheral isolation. The operational and SEU characteristics of several different GaAs logic families are discussed. Recent advances in materials and processing that provide possible solutions to the SEU problem are addressed. C1 SFA INC,LANDOVER,MD 20785. RP McMorrow, D (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 81 TC 26 Z9 27 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 1996 VL 43 IS 2 BP 628 EP 644 DI 10.1109/23.490906 PN 1 PG 17 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA UJ077 UT WOS:A1996UJ07700025 ER PT J AU Marshall, PW Dale, CJ LaBel, KA AF Marshall, PW Dale, CJ LaBel, KA TI Space radiation effects in high performance fiber optic data links for satellite data management SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article AB Fiber optic based technologies are relatively new to satellite applications, and are receiving considerable attention for planned applications in NASA, DOD, and commercial space sectors. We review various activities in recent years aimed at understanding and mitigating radiation related risk in deploying fiber based data handling systems on orbit. Before concluding that there are no critical barriers to designing survivable and reliable systems, we analyze several possible types of radiation effects. Particular attention is given to the subject of particle-induced bit errors in InGaAs p-i-n photodiodes, including a discussion of error mitigation and upset rate prediction methods. C1 SFA INC,LANDOVER,MD 20785. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP Marshall, PW (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 29 TC 31 Z9 32 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 1996 VL 43 IS 2 BP 645 EP 653 DI 10.1109/23.490907 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA UJ077 UT WOS:A1996UJ07700026 ER PT J AU Buchner, S McMorrow, D Melinger, J Campbell, AB AF Buchner, S McMorrow, D Melinger, J Campbell, AB TI Laboratory tests for single-event effects SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article ID LASER SIMULATION; SEU; CF-252; UPSETS; LOGIC AB Integrated circuits are currently tested at accelerators for their susceptibility to single-event effects (SEE)'s. However, because of the cost and limited accessibility associated with accelerator testing, there is considerable interest in developing alternate testing methods. Two laboratory techniques for measuring SEE, one involving a pulsed laser and the other Cf-252, are described in detail in this paper. The pulsed laser provides information on the spatial and temporal dependence of SEE, information that has proven invaluable in understanding and mitigating SEE in spite of the differences in the physical mechanisms responsible for SEE induced by light and by ions. Considerable effort has been expended on developing Cf-252 as a laboratory test for SEE, but the technique has not found wide use because it is severely limited by the low energy and short range of the emitted ions that are unable to reach junctions either covered with dielectric layers or deep below the surface. In fact, there are documented cases where single-event latchup (SEL) testing with Cf-252 gave significantly different results from accelerator testing. A detailed comparison of laboratory and accelerator SEE data is presented in this review in order to establish the limits of each technique. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Buchner, S (reprint author), SFA INC,LANDOVER,MD 20785, USA. NR 23 TC 48 Z9 54 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD APR PY 1996 VL 43 IS 2 BP 678 EP 686 DI 10.1109/23.490911 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA UJ077 UT WOS:A1996UJ07700030 ER PT J AU Esarey, E Sprangle, P Krall, J Ting, A AF Esarey, E Sprangle, P Krall, J Ting, A TI Overview of plasma-based accelerator concepts SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article; Proceedings Paper CT International Workshop on 2nd-Generation Plasma Accelerators CY JUN 26-30, 1995 CL KARDAMYLI, GREECE ID BEAT-WAVE ACCELERATOR; WAKE-FIELD ACCELERATOR; INTENSE LASER-PULSES; RELATIVISTIC LANGMUIR-WAVES; ELECTRON-HOSE INSTABILITY; ION-FOCUSED REGIME; ND-GLASS LASER; UNDERDENSE PLASMA; PARAMETRIC-INSTABILITIES; WAKEFIELD ACCELERATOR AB An overview is given of the physics issues relevant to the plasma wakefield accelerator, the plasma beat-wave accelerator, the laser wakefield accelerator, including the self-modulated regime, and wakefield accelerators driven by multiple electron or laser pulses, Basic properties of linear and nonlinear plasma waves are discussed, as well as the trapping and acceleration of electrons in the plasma wave. Formulas are presented for the accelerating field and the energy gain in the various accelerator configurations, The propagation of the drive electron or laser beams is discussed, including limitations imposed by key instabilities and methods for optically guiding laser pulses, Recent experimental results are summarized. RP USN, RES LAB, DIV PLASMA PHYS, BEAM PHYS BRANCH, WASHINGTON, DC 20375 USA. NR 220 TC 1052 Z9 1070 U1 13 U2 88 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0093-3813 EI 1939-9375 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 1996 VL 24 IS 2 BP 252 EP 288 DI 10.1109/27.509991 PG 37 WC Physics, Fluids & Plasmas SC Physics GA UP870 UT WOS:A1996UP87000002 ER PT J AU Leemans, WP Siders, CW Esarey, E Andreev, NE Shvets, G Mori, WB AF Leemans, WP Siders, CW Esarey, E Andreev, NE Shvets, G Mori, WB TI Plasma guiding and Wakefield generation for second-generation experiments SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article; Proceedings Paper CT International Workshop on 2nd-Generation Plasma Accelerators CY JUN 26-30, 1995 CL KARDAMYLI, GREECE ID INTENSE LASER-PULSES; ELECTROMAGNETIC-WAVES; ACCELERATION; FREQUENCY; DYNAMICS AB A design study has been carried out for a second-generation experiment on laser guiding and wakefield excitation in a channel. From simple scaling laws for the wakefield amplitude, dephasing length, the relativistic group velocity factor gamma(g), and energy gain with and without guiding, we find that the parameter regime for a compact single stage GeV accelerator favors laser systems producing short pulses (10 fs less than or equal to tau less than or equal to 100 fs), each containing an energy on the order of 100 mJ to a few J's. Taking the dephasing length as the maximum acceleration distance, plasma channels with lengths of 1-10 cm and densities of 10(17)-10(19) cm(-3) need to be produced; whereas the design study has been primarily concerned with diffraction and channel guiding, dephasing and depletion limits, and linear wakefield theory, aspects of the effect of the plasma wave on the evolution of the laser pulse are discussed. We find that transverse and longitudinal pulse distortions could indeed affect the generated plasma wave phase velocity and amplitude, and hence may limit the achievable energy gains over the one-dimensional (1-D) linear estimates. Some issues for experiments on prototype small accelerators (100 MeV-1 GeV, cm scale) are also discussed. C1 USN,RES LAB,BEAM PHYS BRANCH,WASHINGTON,DC 20375. UNIV TEXAS,DEPT PHYS,AUSTIN,TX 78712. RUSSIAN ACAD SCI,HIGH ENERGY DENS RES CTR,MOSCOW 127412,RUSSIA. PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90024. RP Leemans, WP (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,CTR BEAM PHYS,BERKELEY,CA 94720, USA. NR 54 TC 69 Z9 69 U1 4 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD APR PY 1996 VL 24 IS 2 BP 331 EP 342 DI 10.1109/27.509997 PG 12 WC Physics, Fluids & Plasmas SC Physics GA UP870 UT WOS:A1996UP87000008 ER PT J AU Ward, SG June, CH Olive, D AF Ward, SG June, CH Olive, D TI PI 3-kinase: A pivotal pathway in T-cell activation? SO IMMUNOLOGY TODAY LA English DT Review ID PHOSPHATIDYLINOSITOL 3-KINASE; LYMPHOCYTES-T; D-3 PHOSPHOINOSITIDES; PROTEIN-KINASE; CD28 RECEPTOR; SH3 DOMAIN; INTERLEUKIN-2; BINDING; WORTMANNIN; 3,4,5-TRISPHOSPHATE AB Coupling and/or activation of phosphoinositide 3-kinase (PI 3-kinase) commonly occurs following the triggering of T-cell surface molecules postulated to modulate early events in T-cell activation (e.g. CD28). Recent studies have revealed important and conflicting data as to the role of PI 3-kinase in T-cell costimulation following CD28 ligation. Here, Stephen Wara and colleagues integrate the available data and propose a role for PI 3-kinase in T-cell activation and costimulation. C1 UNIFORMED SERV UNIV HLTH SCI,DEPT MED,BETHESDA,MD 20889. USN,MED RES INST,IMMUNE CELL BIOL PROGRAM,BETHESDA,MD 20889. INSERM U119,F-13009 MARSEILLE,FRANCE. RP Ward, SG (reprint author), UNIV BATH,SCH PHARM & PHARMACOL,DEPT PHARMACOL,CLAVERTON DOWN,BATH BA2 7AY,AVON,ENGLAND. FU Wellcome Trust NR 116 TC 162 Z9 165 U1 1 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0167-5699 J9 IMMUNOL TODAY JI Immunol. Today PD APR PY 1996 VL 17 IS 4 BP 187 EP 197 DI 10.1016/0167-5699(96)80618-9 PG 11 WC Immunology SC Immunology GA UC449 UT WOS:A1996UC44900011 PM 8871351 ER PT J AU Mehay, SL Hirsch, BT AF Mehay, SL Hirsch, BT TI The postmilitary earnings of female veterans SO INDUSTRIAL RELATIONS LA English DT Article ID VIETNAM-ERA VETERANS; MILITARY SERVICE; TRANSFERABILITY; EXPERIENCE; WAGES; RACE AB The role of women in the military has grown rapidly. Using standard datasets and a special survey of reservists, female veterans are found to have better earnings endowments than nonveterans. Although female veterans have higher unadjusted earnings than nonveterans, a wage disadvantage is found for white but not nonwhite veterans following control for measured and unmeasured skills. Low returns to military service may result from historically limited military opportunities for women and difficulty in transferring skills to civilian jobs. C1 FLORIDA STATE UNIV,DEPT ECON,TALLAHASSEE,FL 32306. RP Mehay, SL (reprint author), USN,POSTGRAD SCH,DEPT SYST MANAGEMENT,MONTEREY,CA 93943, USA. NR 31 TC 7 Z9 7 U1 2 U2 3 PU BLACKWELL PUBLISHERS PI CAMBRIDGE PA 350 MAIN STREET, STE 6, CAMBRIDGE, MA 02148-5023 SN 0019-8676 J9 IND RELAT JI Ind. Relat. PD APR PY 1996 VL 35 IS 2 BP 197 EP 217 DI 10.1111/j.1468-232X.1996.tb00402.x PG 21 WC Industrial Relations & Labor SC Business & Economics GA UH497 UT WOS:A1996UH49700003 ER PT J AU Ching, WM Wang, H Jan, B Dasch, GA AF Ching, WM Wang, H Jan, B Dasch, GA TI Identification and characterization of epitopes on the 120-kilodalton surface protein antigen of Rickettsia prowazekii with synthetic peptides SO INFECTION AND IMMUNITY LA English DT Article ID OUTER-MEMBRANE PROTEIN; S-LAYER PROTEINS; SEQUENCE-ANALYSIS; TYPHI; VIRULENCE; FRAGMENTS; CLONING AB The 120-kDa surface protein antigens (SPAs) of typhus rickettsiae are highly immunogenic and have been shown to be responsible for the species-specific serological reactions of the typhus group rickettsiae. To study the immunochemistry of these proteins, overlapping decapeptides encompassing the whole protein were synthesized on derivatized polyethylene pins. A modified enzyme-linked immunosorbent assay was used to identify epitopes recognized by rabbit hyperimmune antisera to Rickettsia prowazekii SPA. Eight distinct epitopes were mapped by this method in three regions. Four of the epitopes, which were located in the carboxy terminus of mature processed SPA, were strongly competitively inhibited by native folded SPA but not by intact rickettsiae, suggesting that they were on the SPA surface but not exposed on the rickettsial surface. Three of these epitopes were present on both R. prowazekii and Rickettsia typhi SPAs. The immunoreactivities of five epitopes were further characterized by synthesizing modified peptides. Glycine substitution experiments determined the critical residues involved in antibody recognition, while peptide truncation experiments defined the minimum number of residues in the epitopes. The dependence of binding of the peptide epitopes to the polyclonal antisera was mapped to single residues. The limited number and weak reactivity of linear peptide epitopes observed with human and rabbit sera, possibly due to a lack of the methylated amino acids which are present in rickettsia-derived SPA, suggest that the present approach will not provide useful synthetic antigens for diagnosis of typhus infections. RP Ching, WM (reprint author), USN,MED RES INST,VIRAL & RICKETTSIAL DIS PROGRAM,BLDG 17,ROOM 300A,BETHESDA,MD 20889, USA. NR 38 TC 15 Z9 18 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0019-9567 J9 INFECT IMMUN JI Infect. Immun. PD APR PY 1996 VL 64 IS 4 BP 1413 EP 1419 PG 7 WC Immunology; Infectious Diseases SC Immunology; Infectious Diseases GA UC314 UT WOS:A1996UC31400047 PM 8606109 ER PT J AU Wagner, P Little, B Hart, K Ray, R Thomas, D TrzaskomaPaulette, P Lucas, K AF Wagner, P Little, B Hart, K Ray, R Thomas, D TrzaskomaPaulette, P Lucas, K TI Environmental fate of sacrificial zinc anodes and influence of a biofilm SO INTERNATIONAL BIODETERIORATION & BIODEGRADATION LA English DT Article ID BACTERIA; BINDING; METALS AB Laboratory experiments were performed to determine the environmental fate of zinc compounds formed during sacrificial dissolution of zinc anodes in seawater and to further determine the role of biofilms in mobilizing/immobilizing zinc corrosion products. Experimental conditions simulated cathodic protection and overprotection (40x normal) of ship ballast tanks with an anode to cathode ratio of 0.091. Anodic dissolution and percentage of soluble zinc increased with the level of protection. For normal cathodic protection in abiotic seawater, approximately 3% of the sacrificed zinc was dissolved in solution. Additionally, weight loss and percent soluble products increased dramatically in the presence of an agar film, but were unchanged due to the presence of natural marine biofilms. Under overprotection conditions, weight loss did not vary in the presence of surface films. Solid zinc corrosion products were precipitated, suspended in solution, and attached to electrode surfaces. Experimental data were compared with zinc concentrations measured in ballast tanks for two United States Navy surface ships. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Wagner, P (reprint author), USN,RES LAB,BAY ST LOUIS,MS 39529, USA. NR 16 TC 7 Z9 7 U1 1 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0964-8305 J9 INT BIODETER BIODEGR JI Int. Biodeterior. Biodegrad. PD APR-JUN PY 1996 VL 37 IS 3-4 BP 151 EP 157 DI 10.1016/S0964-8305(96)00013-3 PG 7 WC Biotechnology & Applied Microbiology; Environmental Sciences SC Biotechnology & Applied Microbiology; Environmental Sciences & Ecology GA VV635 UT WOS:A1996VV63500002 ER PT J AU Little, B Wagner, P Angell, P White, D AF Little, B Wagner, P Angell, P White, D TI Correlation between localized anodic areas and Oceanospirillum biofilms on copper SO INTERNATIONAL BIODETERIORATION & BIODEGRADATION LA English DT Article ID CORROSION; SURFACES; ALLOYS AB The marine bacterium Oceanospirillum produces copious amounts of exopolymer when grown on copper surfaces and binds Cu+2 from the substratum. The organism and associated exopolymers result in local anodic regions that can be detected by scanning vibrating electrode microscopy. Oceanospirillum was grown in small laminar flow cells with two carbon sources on copper and 316 stainless steel as substrata. The chemical composition of the exopolymer varied with growth medium, but not with substratum. Exopolymers from cells grown in glutamic acid medium on both substrata contained glucose with no other sugar monomers or uronic acids. The quantity of exopolymer did vary with substratum and copper promoted greater polymer production that stainless steel. C1 UNIV TENNESSEE,CTR ENVIRONM BIOTECHNOL,KNOXVILLE,TN 37932. RP Little, B (reprint author), USN,RES LAB,BAY ST LOUIS,MS 39529, USA. NR 20 TC 12 Z9 12 U1 1 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0964-8305 J9 INT BIODETER BIODEGR JI Int. Biodeterior. Biodegrad. PD APR-JUN PY 1996 VL 37 IS 3-4 BP 159 EP 162 DI 10.1016/S0964-8305(96)00014-5 PG 4 WC Biotechnology & Applied Microbiology; Environmental Sciences SC Biotechnology & Applied Microbiology; Environmental Sciences & Ecology GA VV635 UT WOS:A1996VV63500003 ER PT J AU Georgiou, IT Schwartz, IB AF Georgiou, IT Schwartz, IB TI The slow invariant manifold of a conservative pendulum-oscillator system SO INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS LA English DT Article ID WEAKLY DAMPED PENDULUM AB We analyze the motions of a conservative pendulum-oscillator system in the context of invariant manifolds of motion. Using the singular perturbation methodology, we show that whenever the natural frequency of the oscillator is sufficiently larger than that of the pendulum, there exists a global invariant manifold passing through all static equilibrium states and tangent to the linear eigenspaces at these equilibrium states. The invariant manifold, called slow, carries a continuum of slow periodic motions, both oscillatory and rotational. Computations to various orders of approximation to the slow invariant manifold allow analysis of motions on the slow manifold, which are verified with numerical experiments. Motion on the slow invariant manifold is identified with a slow nonlinear normal mode. RP Georgiou, IT (reprint author), USN,RES LAB,DIV PLASMA PHYS,SPECIAL PROJECT NONLINEAR SCI,CODE 67003,WASHINGTON,DC 20375, USA. RI Schwartz, Ira/A-8073-2009 NR 25 TC 12 Z9 12 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-1274 J9 INT J BIFURCAT CHAOS JI Int. J. Bifurcation Chaos PD APR PY 1996 VL 6 IS 4 BP 673 EP 692 DI 10.1142/S0218127496000345 PG 20 WC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences SC Mathematics; Science & Technology - Other Topics GA UX739 UT WOS:A1996UX73900005 ER PT J AU FlippenAnderson, JL George, C Valle, G Valente, E Bianco, A Formaggio, F Crisma, M Toniolo, C AF FlippenAnderson, JL George, C Valle, G Valente, E Bianco, A Formaggio, F Crisma, M Toniolo, C TI Crystallographic characterization of geometry and conformation of TOAC, a nitroxide spin-labelled C-alpha,C-alpha-disubstituted glycine, in simple derivatives and model peptides SO INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH LA English DT Article DE disubstituted glycine; model peptides; nitroxide-containing peptides; peptide crystallography; X-ray crystallography; spin-labelled peptides ID HYDROGEN-BOND DISTANCES; X-RAY-DIFFRACTION; AMINO-ACIDS; PREFERRED CONFORMATION; PARAMAGNETIC MONOMER; CRYSTAL-STRUCTURES; PROTEINS; ANGLES; MOLECULES; CARBON AB The molecular and crystal structures of one derivative and two oligopeptides of TOAC, a nitroxide spin-labelled C-alpha,C-alpha-disubstituted glycine, have been determined by X-ray diffraction. The derivative is the 5(4H)-oxazolone from Piv-TOAC-OH; the oligopeptides are Z-TOAC-(L-Ala)(2)-NHtBu sesquihydrate and pBrBz-TOAC-(L-Ala)(2)-TOAC-L-Ala-NHtBu hemihydrate. Incipient and fully developed right-handed 3(10)-helical conformations are formed by both independent molecules in the asymmetric unit of the terminally blocked tripeptide amide and the terminally blocked pentapeptide amide, respectively. The average geometry and preferred conformation for the piperidine ring of the TOAC residues are also discussed in detail. (C) Munksgaard 1996. C1 UNIV PADUA,DEPT ORGAN CHEM,CNR,BIOPOLYMER RES CTR,I-35131 PADUA,ITALY. USN,RES LAB,STRUCT MATTER LAB,WASHINGTON,DC 20375. RI Crisma, Marco/K-6626-2013 OI Crisma, Marco/0000-0003-3552-4106 NR 57 TC 37 Z9 37 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0367-8377 J9 INT J PEPT PROT RES JI Int. J. Pept. Protein Res. PD APR PY 1996 VL 47 IS 4 BP 231 EP 238 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA UK859 UT WOS:A1996UK85900002 PM 8738647 ER PT J AU Crawford, GP Naciri, J Shashidhar, R Ratna, BR AF Crawford, GP Naciri, J Shashidhar, R Ratna, BR TI Electrooptic performance of electroclinic liquid crystals and their mixtures SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS LA English DT Article DE electroclinic effect; chiral smectic-A; electrooptic effects; gray scale applications ID INDUCED MOLECULAR TILT; SPONTANEOUS POLARIZATION; BEHAVIOR; PHASE; TRANSITION AB The electrooptic properties of two novel electroclinic liquid crystal homologs and their mixtures exhibiting the chiral smectic-A phase with no underlying (low temperature) tilted phase are reported. The field-dependence of the induced tilt angle and of the electroclinic response time of the mixtures are intermediate between those of the pure compounds. A feature of the result is that the mixtures exhibit properties that are attractive from the point-of-view of applications-a broad (65 degrees C) range of the chiral smectic-A, large values of the induced-tilt angle and electroclinic coefficients, and, fast electroclinic response times. C1 USN,RES LAB,WASHINGTON,DC 20375. NR 24 TC 8 Z9 8 U1 1 U2 1 PU JAPAN J APPLIED PHYSICS PI MINATO-KU TOKYO PA DAINI TOYOKAIJI BLDG 24-8 SHINBASHI 4-CHOME, MINATO-KU TOKYO 105, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 1 JI Jpn. J. Appl. Phys. Part 1 - Regul. Pap. Short Notes Rev. Pap. PD APR PY 1996 VL 35 IS 4A BP 2176 EP 2179 DI 10.1143/JJAP.35.2176 PG 4 WC Physics, Applied SC Physics GA UQ188 UT WOS:A1996UQ18800037 ER PT J AU Dorsey, PC Qadri, SB Feldman, JL Horwitz, JS Lubitz, P Chrisey, DB Ings, JB AF Dorsey, PC Qadri, SB Feldman, JL Horwitz, JS Lubitz, P Chrisey, DB Ings, JB TI Coefficients of thermal expansion for barium hexaferrite SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FERRITE; FILMS AB The thermal expansion coefficients along the a axis (alpha(a)) and c axis (alpha(c)) of barium hexaferrite were measured from room temperature to 850 degrees C. The thermal expansion of barium hexaferrite along the a axis and c axis was found to be linear as a function of temperature, indicating constant thermal expansion coefficients over this temperature range. The specific values for alpha(c) and alpha(a) were calculated to be 12.2+/-0.9 and 9.99+/-1.1 ppm/degrees C, respectively. The measurements were performed using a standard x-ray powder diffraction setup equipped with a high temperature stage. (C) 1996 American Institute of Physics. C1 TRANS TECH INC,ADAMSTOWN,MD 21710. RP Dorsey, PC (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 11 TC 22 Z9 22 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 1 PY 1996 VL 79 IS 7 BP 3517 EP 3520 DI 10.1063/1.361402 PG 4 WC Physics, Applied SC Physics GA UC073 UT WOS:A1996UC07300023 ER PT J AU Marmorino, GO Trump, CL AF Marmorino, GO Trump, CL TI Preliminary side-scan ADCP measurements across a ship's wake SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB A preliminary study shows how a standard acoustic Doppler current profiler, tilted so two beams scan horizontally beneath the surface, can be used to map characteristics of a ship's wake. For example, the measurements appear to resolve the flow of surface water outward from the wake centerline. This centerline divergence and the resulting convergence along the edges of the wake help form bands of relatively calm water that often appear in radar imagery of the sea surface. RP Marmorino, GO (reprint author), USN,RES LAB,CODE 7250,4555 OVERLOOK AVE,SW,WASHINGTON,DC 20375, USA. NR 19 TC 12 Z9 12 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD APR PY 1996 VL 13 IS 2 BP 507 EP 513 DI 10.1175/1520-0426(1996)013<0507:PSSAMA>2.0.CO;2 PG 7 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UG675 UT WOS:A1996UG67500020 ER PT J AU Williams, BT Barr, RJ Barrett, TL Everett, MA Lin, F AF Williams, BT Barr, RJ Barrett, TL Everett, MA Lin, F TI Cutaneous pseudosarcomatous polyp: A histological and immunohistochemical study SO JOURNAL OF CUTANEOUS PATHOLOGY LA English DT Article ID DERMATOFIBROMA AB Two unusual acquired polypoid skin lesions exhibited prominent histological atypia, but were biologically benign. Both patients were elderly females. The lesions clinically mimicked fibroepithelial polyp or nevus lipomatosus. Both had been present for about 20 years. One lesion was located on the back, the other on the posterior thigh. Each lesion exhibited dilated, hyalinized vessels in the dermis with focal fibrin deposits, myxoid stroma, and a population of bizarre, pleomorphic spindle to stellate cells, some of which were multinucleated. Occasional atypical mitoses were present. One lesion had abundant admixed fat. Immunohistochemical staining was strongly positive only for vimentin. The lesions share features with degenerating angiofibroma and vaginal pseudosarcomatous polyp. As in these lesions, the atypia is most probably reactive and degenerative. C1 UNIV CALIF IRVINE,MED CTR,DERMATOPATHOL LAB,DEPT DERMATOL & PATHOL,ORANGE,CA 92668. USN,MED CTR,DEPT DERMATOL,SAN DIEGO,CA 92152. UNIV OKLAHOMA,DEPT DERMATOL,OKLAHOMA CITY,OK. NR 10 TC 8 Z9 8 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0303-6987 J9 J CUTAN PATHOL JI J. Cutan. Pathol. PD APR PY 1996 VL 23 IS 2 BP 189 EP 193 DI 10.1111/j.1600-0560.1996.tb01294.x PG 5 WC Dermatology; Pathology SC Dermatology; Pathology GA UD477 UT WOS:A1996UD47700013 PM 8721455 ER PT J AU Parreira, FR Bramwell, JD Roahen, JO Giambarresi, L AF Parreira, FR Bramwell, JD Roahen, JO Giambarresi, L TI Histological response to titanium endodontic endosseous implants in dogs SO JOURNAL OF ENDODONTICS LA English DT Article ID BONE AB Endodontic endosseous implants stabilize teeth that have crown-root ratios compromised by periodontal disease, trauma, or apical resorption. By increasing the crown-root ratio, the implant improves the prognosis of the tooth, thus increasing its longevity, The purpose of this study was to evaluate, in vivo, the healing response to a newly introduced titanium endodontic implant, Eight implants were placed in the maxillary incisors and mandibular premolars of two adult beagle dogs after completion of root canal and osseous preparation, Peri-implant tissues were examined radiographically and histologically at 6 months postinsertion. Radiographically, the periapical area and tissue surrounding the implants seemed normal, Histologically, fibrous connective tissue and healthy bone intimately surrounded the implant, Epithelium or chronic inflammatory cells were not observed along the length of the implant, These findings suggest that titanium is a biocompatible metal when used as an endodontic endosseous implant. C1 USN,ENDODONT DEPT,BRANCH DENT CLIN,WASHINGTON,DC 20374. USN,SCH DENT,ENDODONT DEPT,BETHESDA,MD 20814. USN,SCH DENT,RES DEPT,LAB DIV,BETHESDA,MD 20814. NR 11 TC 8 Z9 8 U1 0 U2 0 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0099-2399 J9 J ENDODONT JI J. Endod. PD APR PY 1996 VL 22 IS 4 BP 161 EP 164 DI 10.1016/S0099-2399(96)80092-6 PG 4 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA UD450 UT WOS:A1996UD45000002 PM 8935011 ER PT J AU Beach, CW Bramwell, JD Hutter, JW AF Beach, CW Bramwell, JD Hutter, JW TI Use of an electronic apex locator on a cardiac pacemaker patient SO JOURNAL OF ENDODONTICS LA English DT Article AB Modern cardiac pacemakers are complex and heterogenous devices. The potential effect of electrically powered instruments on a patient's pacemaker function must be carefully evaluated before treatment, Interference with the pacemaker's function by the instrument depends on the specific type of pacemaker placed and the patient's dependence on it, A case is presented in which an electronic apex locator was used on a patient with a pacemaker, despite the manufacturer's written warning to the contrary, The patient's cardiologist was consulted before treatment. C1 USN,SCH DENT,NATL NAVL DENT CTR,ENDODONT DEPT,BETHESDA,MD 20889. NR 9 TC 7 Z9 8 U1 0 U2 2 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0099-2399 J9 J ENDODONT JI J. Endod. PD APR PY 1996 VL 22 IS 4 BP 182 EP 184 DI 10.1016/S0099-2399(96)80097-5 PG 3 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA UD450 UT WOS:A1996UD45000007 PM 8935016 ER PT J AU Falk, MC Fletcher, MA Williams, TJ Ching, WM Wu, Y Morrison, TK AF Falk, MC Fletcher, MA Williams, TJ Ching, WM Wu, Y Morrison, TK TI Aggregation of serum proteins with lipopolysaccharide (LPS): Characterization of the precipitable LPS-protein complex SO JOURNAL OF ENDOTOXIN RESEARCH LA English DT Article ID ANTIBODY-INDEPENDENT ACTIVATION; HIGH-DENSITY LIPOPROTEINS; BACTERIAL LIPOPOLYSACCHARIDE; LABORATORY MODELS; SEPTIC SHOCK; MOUSE SERUM; LIPID-A; RAT; COMPONENT; BINDING AB We have employed an in vitro system to study the interactions between rat serum proteins and lipopolysaccharide (LPS) under conditions similar to those commonly employed in endotoxemia studies. Immediately after mixing, a small fraction of the LPS micelles form a readily precipitable aggregate with serum proteins. Aggregate formation is measurable at LPS concentrations equivalent to maximal serum loads at the lethal threshold in endotoxic shock studies. The amount of aggregate increases with increasing LPS concentration. While the protein content of this aggregate remains stable over the 60 min studied, the LPS content decreases. Only three serum protein species comprise 85-90% of the protein bound in the aggregate: albumin, complement factor C3b and iC3b, and immunoglobulins G and M. Much larger amounts of serum protein-LPS aggregates are formed using serum from animals pre-exposed to sublethal levels of LPS. The results help better characterize the physical-chemical properties of LPS as it is employed in endotoxic shock models in normal and pre-exposed animals and may help explain the altered clearance profiles experienced in these models. RP Falk, MC (reprint author), USN,MED RES INST,SEPT SHOCK RES PROGRAM,8901 WISCONSIN AVE,BETHESDA,MD 20889, USA. NR 46 TC 0 Z9 0 U1 0 U2 0 PU CHURCHILL LIVINGSTONE PI EDINBURGH PA JOURNAL PRODUCTION DEPT, ROBERT STEVENSON HOUSE, 1-3 BAXTERS PLACE, LEITH WALK, EDINBURGH, MIDLOTHIAN, SCOTLAND EH1 3AF SN 0968-0519 J9 J ENDOTOXIN RES JI J. Endoxtin Res. PD APR PY 1996 VL 3 IS 2 BP 129 EP 142 PG 14 WC Biochemistry & Molecular Biology; Immunology; Medicine, Research & Experimental; Microbiology SC Biochemistry & Molecular Biology; Immunology; Research & Experimental Medicine; Microbiology GA UY276 UT WOS:A1996UY27600006 ER PT J AU Ehrhardt, JP Spring, SK AF Ehrhardt, JP Spring, SK TI Component and procedural improvements for the T-62T-40-7 gas turbine in the LCAC fleet SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 39th International Gas Turbine and Aeroengine Congress and Exposition CY JUN 13-16, 1994 CL THE HAGUE, NETHERLANDS AB The Sundstrand Power Systems T-62T-40-7 Gas Turbine Auxiliary Power Unit (APU) was adapted from an aircraft-borne APU to a marine application on the U.S. Navy's Landing Craft Air Cushion (LCAC). Although the LCAC APU experienced less operating time than its aircraft version, the environmental conditions that exist cause unusual wear and component failures. Component and procedural improvements have been developed to extend the reliability of the T-62T-40-7 on board the LCAC. C1 USN,CTR SURFACE WARFARE,CARDEROCK DIV,GAS TURBINE BRANCH,PHILADELPHIA,PA 19112. RP Ehrhardt, JP (reprint author), USN,SEA SYST COMMAND,AMPHIBIOUS WARFARE PROGRAM,WASHINGTON,DC 20362, USA. NR 3 TC 0 Z9 0 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD APR PY 1996 VL 118 IS 2 BP 369 EP 374 DI 10.1115/1.2816598 PG 6 WC Engineering, Mechanical SC Engineering GA UJ384 UT WOS:A1996UJ38400018 ER PT J AU Patterson, JS Harris, H AF Patterson, JS Harris, H TI The installation, testing, and lessons learned of the TF40B Gas Turbine Test Facility SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 40th International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 05-08, 1995 CL HOUSTON, TX AB The TF40B Gas Turbine Test Facility is the only dedicated Landing Craft, Air Cushion main propulsion engine test complex available to the U.S. Navy. This facility, located at the Naval Surface Warfare Center, Carderock Division (NSWCCD) in Philadelphia, PA, began operation in August, 1992. Since then, the test engine has logged approximately 230 starts and 350 operating hours. This paper will present the installation, testing, and lessons learned of the the TF40B test facility. The installation section will discuss the modifications made to the existing test facility to accept the TF40B engine. The lest section will include the Foreign Object Damage (FOD) screen evaluation, both on-line and crank wash detergent fluid evaluations, cold weather fuel testing, engine vent line testing and Aerojet 5 oil evaluation. The lessons learned section will include problems related to the electric starter, waterbrake, inlet and exhaust systems, data acquisition system, instrumentation control panel, and the test cell equipment arrangement. RP Patterson, JS (reprint author), USN,CTR SURFACE WARFARE,CARDEROCK DIV,PHILADELPHIA,PA 19112, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD APR PY 1996 VL 118 IS 2 BP 375 EP 379 DI 10.1115/1.2816599 PG 5 WC Engineering, Mechanical SC Engineering GA UJ384 UT WOS:A1996UJ38400019 ER PT J AU Doolan, DL Sedegah, M Hedstrom, RC Hobart, P Charoenvit, Y Hoffman, SL AF Doolan, DL Sedegah, M Hedstrom, RC Hobart, P Charoenvit, Y Hoffman, SL TI Circumventing genetic restriction of protection against malaria with multigene DNA immunization: CD8(+) T cell-, interferon gamma-, and nitric oxide-dependent immunity SO JOURNAL OF EXPERIMENTAL MEDICINE LA English DT Article ID FALCIPARUM CIRCUMSPOROZOITE PROTEIN; CYTOTOXIC LYMPHOCYTES-T; TUMOR-NECROSIS-FACTOR; PLASMODIUM-YOELII; MONOCLONAL-ANTIBODIES; L-ARGININE; VACCINE DEVELOPMENT; SPOROZOITES; HEPATOCYTES; CLONES AB Despite efforts to develop vaccines that protect against malaria by inducing CD8(+) T cells that kill infected hepatocytes, no subunit vaccine has been shown to circumvent the genetic restriction inherent in this approach, and little is known about the interaction of subunit vaccine-induced immune effectors and infected hepatocytes. We now report that immunization with plasmid DNA encoding the Plasmodium yoelii circumsporozoite protein protected one od five strains of mice against malaria (H-2(d), 75%); a PyHEP17 DNA vaccine protected three of the five strains (H-2(a), 71%; H-2(k), 54%; H-2(d), 26%); and the combination protected 82% of H-2(a), 90% of H-2(k), and 88% of H-2(d) mice. Protection was absolutely dependent on CD8(+) T cells, IFN-gamma, or nitric oxide. These data introduce a new target of protective preerythrocytic immune responses, PyHEP17 and its P. falciparum homologue, and provide a realistic perspective on the opportunities and challenges inherent in developing malaria vaccines that target the infected hepatocyte. C1 USN,MED RES INST,MALARIA PROGRAM,BETHESDA,MD 20889. UNIV MARYLAND,BALTIMORE,MD 21201. VICAL INC,SAN DIEGO,CA 92121. RI Doolan, Denise/F-1969-2015 NR 50 TC 224 Z9 233 U1 1 U2 5 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 222 E 70TH STREET, NEW YORK, NY 10021 SN 0022-1007 J9 J EXP MED JI J. Exp. Med. PD APR 1 PY 1996 VL 183 IS 4 BP 1739 EP 1746 DI 10.1084/jem.183.4.1739 PG 8 WC Immunology; Medicine, Research & Experimental SC Immunology; Research & Experimental Medicine GA UH144 UT WOS:A1996UH14400047 PM 8666931 ER PT J AU Mobarry, CM Fedder, JA Lyon, JG AF Mobarry, CM Fedder, JA Lyon, JG TI Equatorial plasma convection from global simulations of the Earth's magnetosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; BIRKELAND CURRENTS; ALIGNED CURRENTS; NORTHWARD; MODEL; IMF; ALGORITHMS AB The convection of plasma in the closed field region of the Earth's magnetosphere is an important consequence and a diagnostic of the coupling of solar wind momentum and energy into the magnetosphere; In the outer regions the nature of the flow can help to distinguish between different coupling processes; for example, between (1) a global reconnection process between closed geomagnetic held and the interplanetary magnetic field (IMF), or (2) a local diffusive-viscous interaction. In the inner magnetosphere, the convection is responsible for both energization and redistribution of energetic and thermal plasmas. This paper presents the first results for convection of plasma in the closed field magnetosphere derived from a self-consistent, three-dimensional, magnetohydrodynamic simulation model of the Earth's magnetosphere. The results are shown as electric potential patterns in the equatorial plane. The equipotential contours, which are interpreted as plasma streamlines, demonstrate that line reconnection between closed geomagnetic field and the IMF is the dominant coupling process for southward IMF in the parameter range studied. Results are presented from three simulations, that is, southward, northward, and duskward IMF. For the southward IMF case, the quasi-steady cross polar cap electric potential is essentially equal to the bow reconnection voltage. The results show that reconnection on the open/closed magnetic field boundary is important for northward IMF also. In this case, the reconnection process takes place at the two polar cusps, and is an inherently unsteady process even though it leads to a quasi-steady convection potential in the ionosphere. The implications of these results, for the nature of the solar wind magnetosphere coupling, are discussed. Moreover, the convection results are closely related to the polar Birkeland current systems, which are the self-consistent consequences of the coupling process and in turn create the ionospheric convection flow. C1 USN, RES LAB, BEAM PHYS BRANCH, WASHINGTON, DC 20375 USA. DARTMOUTH COLL, DEPT PHYS & ASTRON, HANOVER, NH 03755 USA. SFA INC, LANDOVER, MD 20785 USA. RP Mobarry, CM (reprint author), NASA, GODDARD SPACE FLIGHT CTR, DIV SPACE DATA & COMP, CODE 934, GREENBELT, MD 20771 USA. NR 39 TC 34 Z9 34 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD APR 1 PY 1996 VL 101 IS A4 BP 7859 EP 7874 DI 10.1029/95JA02301 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UD939 UT WOS:A1996UD93900020 ER PT J AU Rowland, HL Fernsler, RF Bernhardt, PA AF Rowland, HL Fernsler, RF Bernhardt, PA TI Breakdown of the neutral atmosphere in the D region due to lightning driven electromagnetic pulses SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID LOWER IONOSPHERE; IONIZATION; LAYER AB Electromagnetic pulses (EMP) driven by Lightning can cause breakdown of the neutral atmosphere in the lower D-region. Using a computer simulation model, we study the dependence of the breakdown on the pulse strength, the orientation of the lightning discharge, the ambient plasma density, the ionization model, and the neutral density. For a discharge along a straight Line the EMP is strongest in the plane perpendicular to the current so that for a given current, horizontal discharges will radiate the D-region more strongly than a vertical discharge. For horizontal currents, breakdown occurs for E(100) > 20 V/m (I > 55 kA) in a low-density, nighttime ionosphere, where E(100) is the amplitude of the pulse normalized to 100 km from the discharge and I is the discharge current. Vertical strokes require E(100) > 50 V/m (I > 140 kA). Discharges with higher currents and fields form ionization patches which are larger in volume, larger in degree of ionization, and lower in altitude. The ionization is most sensitive to the pulse strength, pulse orientation, ambient plasma density, and neutral gas density at breakdown threshold. Higher ambient plasma densities reduce the ionization, but for large EMP, breakdown can occur even with high daytime densities. The breakdown increases the plasma density which acts to limit the EMP and ionization. This feedback reduces the sensitivity of the breakdown to the ionization model. Neutral density variations, such as caused by atmospheric gravity waves, can cause spatial variations in the ionization density. RP Rowland, HL (reprint author), USN,RES LAB,BEAM PHYS BRANCH,DIV PLASMA PHYS,CODE 6790,WASHINGTON,DC 20375, USA. NR 26 TC 34 Z9 34 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD APR 1 PY 1996 VL 101 IS A4 BP 7935 EP 7945 DI 10.1029/95JA03519 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UD939 UT WOS:A1996UD93900028 ER PT J AU Savarino, SJ McVeigh, A Watson, J Cravioto, A Molina, J Echeverria, P Bhan, MK Levine, MM Fasano, A AF Savarino, SJ McVeigh, A Watson, J Cravioto, A Molina, J Echeverria, P Bhan, MK Levine, MM Fasano, A TI Enteroaggregative Escherichia coli heat-stable enterotoxin is not restricted to enteroaggregative E-coli SO JOURNAL OF INFECTIOUS DISEASES LA English DT Article ID ENTEROPATHOGENIC SEROTYPES; DIARRHEA AB Enteroaggregative Escherichia coli (EAggEC) have been implicated as diarrheal pathogens in several settings, Some EAggEC produce a distinct heat-stable enterotoxin named EAST1, The distribution and prevalence of the EAST1 gene in selected groups of bacterial enteropathogens were determined by colony hybridization, One hundred percent of 75 O157:H7 enterohemorrhagic E. coli (EHEC), 41% of 227 EAggEC, 41% of 149 enterotoxigenic E. coli, 22% of 65 enteropathogenic E. coli (EPEC), and 38% of 47 E. coli stool isolates from asymptomatic children hybridized with an EAST1 DNA probe, None of 55 enteroinvasive E. coli, 12 Yersinia enterocolitica, or 20 Vibrio cholerae non-O1 strains were EAST1 probe-positive, Concordance between EAST1 genotype and enterotoxicity was shown in examined strains of EAggEC, EHEC, and EPEC, The gene encoding EAST1 is more broadly distributed among diarrheogenic E. coli than previously known and may represent an additional determinant in the pathogenesis of E. coli diarrhea. C1 USN, MED RES INST, ENTER DIS PROGRAM, BETHESDA, MD USA. UNIV MARYLAND, SCH MED, DEPT PEDIAT, BALTIMORE, MD 21201 USA. UNIV MARYLAND, SCH MED, DEPT MED, BALTIMORE, MD 21201 USA. UNIV NACL AUTONOMA MEXICO, DEPT PUBL HLTH, MEXICO CITY, DF, MEXICO. ARMED FORCES RES INST MED SCI, DEPT BACTERIOL, BANGKOK 10400, THAILAND. UNIV MARYLAND, SCH MED, CTR VACCINE DEV, BALTIMORE, MD 21201 USA. ALL INDIA INST MED SCI, DEPT PEDIAT, NEW DELHI, INDIA. NR 15 TC 139 Z9 140 U1 0 U2 3 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA SN 0022-1899 EI 1537-6613 J9 J INFECT DIS JI J. Infect. Dis. PD APR PY 1996 VL 173 IS 4 BP 1019 EP 1022 PG 4 WC Immunology; Infectious Diseases; Microbiology SC Immunology; Infectious Diseases; Microbiology GA UB274 UT WOS:A1996UB27400035 PM 8603943 ER PT J AU Chakarian, V Idzerda, YU Lin, HJ Gutierrez, CJ Prinz, GA Meigs, G Chen, CT AF Chakarian, V Idzerda, YU Lin, HJ Gutierrez, CJ Prinz, GA Meigs, G Chen, CT TI Element-specific vector magnetometry of buried layers SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 2nd International Symposium on Metallic Multilayers (MML 95) CY SEP 11-14, 1995 CL CAVENDISH LAB, CAMBRIDGE, ENGLAND HO CAVENDISH LAB AB Magnetic circular dichroism is used as an element-specific vector magnetometer to determine the behavior of a buried 3.3 monolayer Mn film in a Fe25Co75/Mn/Fe25Co75 trilayer, which exhibits a 90 degrees coupling between the FeCo layers. The data indicate a net ferromagnetic Mn moment canted by 23 degrees from the net Fe (and Co) moments. C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. SW TEXAS STATE UNIV,DEPT PHYS,SAN MARCOS,TX 78666. RP Chakarian, V (reprint author), USN,RES LAB,CODE 6345,WASHINGTON,DC 20375, USA. NR 6 TC 5 Z9 6 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 APR PY 1996 VL 156 IS 1-3 BP 265 EP 266 DI 10.1016/0304-8853(95)00863-2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA UV358 UT WOS:A1996UV35800111 ER PT J AU Johnson, M AF Johnson, M TI Spin injection in metals: The bipolar spin transistor SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 2nd International Symposium on Metallic Multilayers (MML 95) CY SEP 11-14, 1995 CL CAVENDISH LAB, CAMBRIDGE, ENGLAND HO CAVENDISH LAB ID CHARGE AB Transport equations for spin transistor action, appropriate for realistic models of materials and interfaces, are developed from a detailed microscopic model. Experimental results from prototypes are summarized in the context of device applications. Using spin injection to study spin accumulation in superconducting films is discussed. RP Johnson, M (reprint author), USN,RES LAB,CODE 6345,4555 OVERLOOK AVE SW,WASHINGTON,DC 20375, USA. NR 15 TC 28 Z9 28 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 APR PY 1996 VL 156 IS 1-3 BP 321 EP 324 DI 10.1016/0304-8853(95)00883-7 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA UV358 UT WOS:A1996UV35800132 ER PT J AU Turner, CR Losasso, TJ Muzzi, DA Weglinski, MR AF Turner, CR Losasso, TJ Muzzi, DA Weglinski, MR TI Brain relaxation and cerebrospinal fluid pressure during craniotomy for resection of supratentorial mass lesions SO JOURNAL OF NEUROSURGICAL ANESTHESIOLOGY LA English DT Article DE anesthetics, volatile; cerebrospinal fluid pressure; brain relaxation; intracranial pressure; surgery, neurologic; surgery, craniotomy; supratentorial neoplasms ID CEREBRAL BLOOD-VOLUME; NITROUS-OXIDE; ISOFLURANE; ANESTHESIA; DOGS; CSF; REABSORPTION; RESISTANCE; HALOTHANE; FENTANYL AB Neurosurgery can be complicated by the clinical situation commonly referred to as ''tight brain,'' in which the brain presses against the inner table of the skull or protrudes through the craniotomy site. We report here a retrospective study of 32 patients who had undergone elective craniotomy for resection of supratentorial mass lesions. We determined the relationship between lumbar cerebrospinal fluid pressure (CSFP) and brain relaxation and whether brain relaxation varies with anesthetic technique. Patients had received one of four anesthetic techniques: 1 MAC isoflurane (ISO), 1 MAC desflurane (DES), 50% N2O with 0.5 MAC ISO, or 50% N2O with 0.5 MAC DES. Lumbar CSFP had been recorded before the induction of anesthesia (baseline) and immediately prior to dural incision. Charts were retrospectively reviewed for evidence of tight brain, which was considered present if mannitol had been administered, CSF had been drained via the lumbar needle, or the surgical dictation noted the brain was tight at the time of dural incision. Tight brain occurred in 10 of 32 patients. CSFP (mean +/- SD) was significantly greater in the tight than in the nontight group both at baseline (11 +/- 5 vs. 8 +/- 3 mm Hg, p < 0.05) and immediately prior to dural incision (13 +/- 7 vs. 9 +/- 4 mm Hg, p < 0.05). Tight brain did not occur in any patient with CSFP < 6 mm Hg, but it did occur in all patients with CSFP > 17 mm Hg. Within the range of 6-17 mm Hg, CSFP was not predictive of brain relaxation. Tight brain was more common in patients receiving 1 MAC ISO or DES (9 of 20 patients; 45%) than in patients receiving 0.5 MAC ISO or DES with 50% N2O (1 of 12 patients; 8%, p < 0.05). We conclude that in patients undergoing elective craniotomy for resection of a supratentorial mass lesion, brain relaxation is not predictive of CSFP. Although CSFP values at the extremes of the observed distribution (>17 mm Hg or <6 mm Hg) did correlate with brain relaxation, within the range of 6-17 mm Hg, CSFP did not predict brain relaxation. Additionally, the data from this study suggest that in patients undergoing elective craniotomy for resection of a supratentorial mass lesion, tight brain may occur with a lower frequency in patients receiving 0.5 MAC ISO or DES with 50% N2O than in patients receiving 1 MAC ISO or DES. C1 MAYO CLIN & MAYO FDN,DEPT ANESTHESIOL,ROCHESTER,MN 55905. USN HOSP,DEPT ANESTHESIOL,SAN DIEGO,CA. DULUTH ANESTHESIA ASSOCIATES,DULUTH,MN. NR 25 TC 12 Z9 12 U1 0 U2 1 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0898-4921 J9 J NEUROSURG ANESTH JI J. Neurosurg. Anesthesiol. PD APR PY 1996 VL 8 IS 2 BP 126 EP 132 PG 7 WC Anesthesiology; Clinical Neurology; Surgery SC Anesthesiology; Neurosciences & Neurology; Surgery GA UC301 UT WOS:A1996UC30100005 PM 8829559 ER PT J AU Ngai, KL AF Ngai, KL TI On the dynamics of the highly anisotropic glass transition in a columnar discotic liquid crystal SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID DIELECTRIC-RELAXATION; DENSITY-FLUCTUATIONS; MOLECULAR-DYNAMICS; AMORPHOUS POLYMERS; CORRELATED SYSTEMS; PHASE-SPACE; MESOPHASES; SCATTERING; DIFFUSION; VOLUME AB Recent experimental findings show that the dynamics and thermodynamics of glass transition in a columnar discotic liquid crystal are highly anisotropic. This anisotropy is discussed in the context of the coupling theory. The difference of almost thirty degrees Kelvin between the glass transition temperature of axial rotation around the columnar axis and that of the intracolumnar thermal expansion coefficient is rationalized by the disparity of intermolecular constraints (coupling parameter, n) for these two types of motion. Axial rotation of the disc-like molecule about the columnar axis is least constrained by intermolecular interactions, having a small coupling parameter and a weak T-g-scaled temperature dependence of its relaxation time. Dielectric and NMR data which probe the axial rotational motion are consistent with this expected behavior. Comparison with wholly amorphous glass-forming small molecule liquids show that the T-g-scaled temperature dependence of the alpha-relaxation of the columnar discotic liquid crystal is the weakest known. This unusual property is due to the cr-relaxation associated with the axial motion, involving only a single degree of freedom. However, I expect that motion along the columnar axis will be more intermolecularly constrained and its relaxation time to have a much stronger T-g-scaled temperature dependence. This prediction cannot be fully verified until measurement of the dynamics of motion along the columnar axis becomes available. RP Ngai, KL (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 27 TC 6 Z9 6 U1 1 U2 3 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 APR PY 1996 VL 197 IS 1 BP 1 EP 7 DI 10.1016/0022-3093(95)00546-3 PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA UJ190 UT WOS:A1996UJ19000001 ER PT J AU Berliner, MJ Solecki, R AF Berliner, MJ Solecki, R TI Wave propagation in fluid-loaded, transversely isotropic cylinders .1. Analytical formulation SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID CYLINDRICAL-SHELLS AB The problem of wave propagation in an infinite, fluid-loaded, homogeneous, transversely isotropic cylinder is studied within the framework of the linearized, three-dimensional theory of elasticity. The equations of motion of the cylinder are formulated using the constitutive equations of a transversely isotropic material with a preferred material direction collinear with the longitudinal axis of the cylinder. The equations of motion of the internal and external fluids are formulated using the constitutive equations of an inviscid fluid. Displacement potentials are used to solve the equations of motion of the cylinder and the fluids. The frequency equation of the coupled system, consisting of the cylinder and the internal and external fluids, is developed under the assumption of perfect-slip boundary conditions at the fluid-solid interfaces. This frequency equation is general in axial wave number k, circumferential wave number n, cylinder wall thickness h, and radial frequency omega. Simplifications to the frequency equation for the cases of zero wave number and material isotropy are discussed. (C) 1996 Acoustical Society of America. C1 UNIV CONNECTICUT,DEPT MECH ENGN,STORRS,CT 06269. RP Berliner, MJ (reprint author), USN,UNDERSEA WARFARE CTR DETACHMENT,SUBMARINE SONAR DEPT,NEW LONDON,CT 06320, USA. RI CHEN, Jiangang/A-1549-2011 NR 19 TC 32 Z9 32 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD APR PY 1996 VL 99 IS 4 BP 1841 EP 1847 DI 10.1121/1.415365 PN 1 PG 7 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UF398 UT WOS:A1996UF39800004 ER PT J AU Berliner, MJ Solecki, R AF Berliner, MJ Solecki, R TI Wave propagation in fluid-loaded, transversely isotropic cylinders .2. Numerical results SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID CYLINDRICAL-SHELLS AB The frequency equation of a coupled system consisting of an infinitely long, fluid-loaded, homogeneous, transversely isotropic cylinder was derived in Part I [J. Acoust. Sec. Am. 99, 1841-1847 (1996)]. In this paper, Part n, the frequency spectra for the n=1 nonaxisymmetric modes of wave propagation are presented for hollow cylinders, fluid-filled cylinders, and cylinders that are fluid filled and immersed in fluid. These frequency spectra consist of the first three branches corresponding to the flexural mode, the longitudinal mode, and the circumferential mode. Since propagation modes are of primary interest, branches extending into the imaginary and complex wave-number domain are not included in this study. Numerical results for an isotropic (linearly elastic) rubber cylinder are compared to the results for a highly anisotropic, fiber-reinforced cylinder. The material properties of the rubber cylinder are identical to the properties of the matrix material of the fiber-reinforced cylinder. It is shown that the characteristics of wave propagation in the fiber-reinforced cylinder, with and without fluid loading, are markedly different from the characteristics of wave propagation in the isotropic cylinder. (C) 1996 Acoustical Society of America. C1 UNIV CONNECTICUT,DEPT MECH ENGN,STORRS,CT 06269. RP Berliner, MJ (reprint author), USN,UNDERSEA WARFARE CTR DETACHMENT,SUBMARINE SONAR DEPT,NEW LONDON,CT 06320, USA. RI CHEN, Jiangang/A-1549-2011 NR 19 TC 8 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD APR PY 1996 VL 99 IS 4 BP 1848 EP 1853 DI 10.1121/1.415366 PN 1 PG 6 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UF398 UT WOS:A1996UF39800005 ER PT J AU McCollum, MD Siders, CM AF McCollum, MD Siders, CM TI Modal analysis of a structure in a compressible fluid using a finite element boundary element approach SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB One approach to modeling the resonant behavior of structures in a compressible fluid is to use finite elements to describe the structure and boundary elements to describe the fluid. The fluid loading is characterized by a complex, frequency-dependent influence matrix that is combined with the frequency-independent stiffness and mass matrices obtained from the finite element model. This approach works well for determining the fluid-loaded harmonic response of the structure over a specified frequency range, if one knows the appropriate frequency range over which to perform the analysis. Since the in-fluid resonance frequency is usually not known, the designer must choose successive frequency sets until the resonance peak is found. This paper describes a method that eliminates this guesswork by computing the in-fluid eigenfrequency of the mode of interest using boundary elements to model the fluid loading. The procedure is iterative; beginning with the in vacuo eigenfrequency and continuing until the in-fluid eigenvalue converges. The designer may then perform a harmonic analysis in a narrow band about the computed eigenfrequency to obtain the structural and/or acoustic response levels. The accuracy and efficiency of the technique is demonstrated with two examples: a spherical shell and a low-frequency projector, both in water. RP McCollum, MD (reprint author), USN,RES LAB,UNDERWATER SOUND REFERENCE DETACHMENT,ORLANDO,FL 32856, USA. NR 12 TC 18 Z9 27 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD APR PY 1996 VL 99 IS 4 BP 1949 EP 1957 DI 10.1121/1.415379 PN 1 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA UF398 UT WOS:A1996UF39800018 ER PT J AU Norton, GV Novarini, JC AF Norton, GV Novarini, JC TI The effect of sea-surface roughness on shallow water waveguide propagation: A coherent approach SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID PARABOLIC WAVE-EQUATION; SOUND-PROPAGATION; SCATTERING; BOUNDARIES AB Standard propagation models in underwater acoustics (e.g., normal modes, PE) are deterministic in nature, i.e., they deal with a single realization of the environment. Additionally, for mathematical reasons, they typically treat the sea surface as a flat pressure-release surface. Effects of sea surface and bottom roughness are incorporated through a loss mechanism. This is accomplished by including an additional attenuation factor based on coherent loss of the surface-interacting component of the propagating held. This type of correction presents a mathematically inconsistent model, since usually results from stochastic scattering models are applied to results from single realizations of the stochastic medium. Moreover, scattering kernels are generally derived assuming a homogeneous medium underlying the sea surface, an assumption incompatible with a realistic environment. Using a numerical model [Norton et al., J. Acoust. Sec. Am. 97, 2173-2180 (1995)] that combines a high fidelity Parabolic Equation propagation model with the conformal mapping technique developed by Dozier [L. B. Dozier, J. Acoust. Sec. Am. 75, 1415-1432 (1984)] to handle surface roughness in a marching algorithm, forward propagation with a single realization of a rough sea surface overlying a complex ocean environment can be modeled in a mathematically consistent way. This technique is applied to the problem of shallow water propagation with a rough sea surface. For the adopted environment and range of rms roughnesses considered (0.282.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UG739 UT WOS:A1996UG73900006 ER PT J AU Burk, SD Thompson, WT AF Burk, SD Thompson, WT TI The summertime low-level jet and marine boundary layer structure along the California coast SO MONTHLY WEATHER REVIEW LA English DT Article ID OCEAN DYNAMICS EXPERIMENT; NORTHERN CALIFORNIA; MODEL; PREDICTION; ATMOSPHERE; FLOW; INVERSION; MOUNTAINS AB This paper examines the strong, summertime northerly low-level jet (LLJ) that frequently exists along the California coast. The persistent synoptic-scale pressure distribution(North Pacific high to the west, thermal low to the east) and baroclinity created by the juxtaposition of the heated continent and the cool marine layer produce the mean structure of this LLJ. Strong diurnal thermal forcing, coupled with topographic influences on the flow, modulate the jet structure, position, and intensity. A mesoscale model is used to examine many of the complex facets of the LLJ flow dynamics. Several sensitivity studies, in addition to a control experiment, aid in this investigation. Principal findings of this study include the following. The pronounced east-west slope of the marine planetary boundary layer (MPBL) is not due primarily to colder SST values along the coast. Dynamically forced low-level coastal divergence, coupled with synoptic-scale divergence, appears to be dominant in determining MPBL inversion slope and profoundly impacts the coastal stratus distribution. Maximum baroclinity occurs in midafternoon, whereas the LLJ maximum occurs in the evening. An analytical treatment of the dynamics shows that diurnal variation of the jet-level baroclinity, coupled with inertial and friction effects, explain this jet timing. In a no-terrain simulation, the jet is broader, somewhat weaker, and tilts more to the west than in our control case. A deeper boundary layer occurs over the location of the Central Valley of California in the no-terrain simulation than in the more realistic control run. Consequently, a delay in time of maximum baroclinity aloft occurs in the no-terrain case, and the LLJ maximum occurs later as compared to the control. The core of the jet, which resides in the inversion capping the MPBL, lowers and moves toward the coast during the day and lifts and moves farther away from the coast at night. Meso-beta-scale structure of the LLJ along the coast is forced by the topography of points and capes. The mesoscale model simulation has supercritical Bow, showing expansion fan characteristics, in the MPBL around Cape Mendocino. Model results are consistent with mountain wave theory in that a near-surface wind speed maximum and pressure minimum are modeled on the lee side of Cape Mendocino. The LLJ maxima in the lee of points and capes produce local maxima in surface stress. The position of these wind stress maxima correlate well with the location of cold pools observed in the SST, implying that locally enhanced, wind-forced upwelling plays a major role in the creation of such cold SST patches. RP USN, RES LAB, MARINE METEOROL DIV, MONTEREY, CA 93943 USA. NR 34 TC 94 Z9 94 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD APR PY 1996 VL 124 IS 4 BP 668 EP 686 DI 10.1175/1520-0493(1996)124<0668:TSLLJA>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UG739 UT WOS:A1996UG73900008 ER PT J AU Langland, RH Errico, RM AF Langland, RH Errico, RM TI Use of an adjoint model for finding triggers for alpine lee cyclogenesis - Comment SO MONTHLY WEATHER REVIEW LA English DT Article C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. RP Langland, RH (reprint author), USN,RES LAB,MARINE METEOROL DIV,7 GRACE HOPPER AVE,MONTEREY,CA 93943, USA. NR 7 TC 5 Z9 5 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD APR PY 1996 VL 124 IS 4 BP 757 EP 760 DI 10.1175/1520-0493(1996)124<0757:COOAAM>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UG739 UT WOS:A1996UG73900015 ER PT J AU Battle, PR Bashkansky, M Mahon, R Reintjes, J AF Battle, PR Bashkansky, M Mahon, R Reintjes, J TI Subsurface defect detection in ceramic materials using optical gating techniques SO OPTICAL ENGINEERING LA English DT Article DE ceramic materials; nondestructive evaluation; optical gating ID FEMTOSECOND AB We demonstrate the use of optical gating techniques for determining the size and location of defects in advanced ceramic materials. The subsurface region in a bearing-grade silicon nitride ceramic material is probed using an optical gate based on broadband Raman scattering. Experimental results indicate that the size and distribution of small subsurface defects can be determined. (C) 1996 Society of Photo-Optical instrumentation Engineers. C1 USN,RES LAB,LASER PHYS BRANCH,WASHINGTON,DC 20375. RP Battle, PR (reprint author), USN ACAD,DEPT PHYS,ANNAPOLIS,MD 21401, USA. NR 15 TC 6 Z9 6 U1 0 U2 1 PU SOC PHOTO-OPT INSTRUM ENG PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD APR PY 1996 VL 35 IS 4 BP 1119 EP 1123 DI 10.1117/1.601031 PG 5 WC Optics SC Optics GA UE920 UT WOS:A1996UE92000032 ER PT J AU Korendyke, CM Socker, DG Brueckner, GE Schwenn, R AF Korendyke, CM Socker, DG Brueckner, GE Schwenn, R TI Measurement of near-specular visible-wavelength scattered light from two superpolished ''coronagraph quality'' mirrors SO OPTICAL ENGINEERING LA English DT Article DE corona; solar; coronagraph; scatterometer; near-specular; stray radiation ID SPACE AB Several coronagraphs with mirror objectives are planned or have been constructed for terrestrial and space-based observatories. To justify the nontraditional choice of an internally occulted, reflective design for the inner coronal channel of the large-angle spectrometric coronagraph (LASCO) instrument constructed for the Solar Heliospheric Observatory satellite, we measured the near-specular (0.09 to 1.25 deg) scatter of two superpolished, spherical coronagraph mirrors with a unique geometry scatterometer. The visible stray light emanating from defect-free portions of the best mirror was measured to be 3.5 x 10(-7) B/B. (coronal brightness relative to the mean solar brightness) at 2R. (heliocentric distance in solar radii) and 2 x 10(-7) B/B. at 3R. These levels are well below typical sky brightnesses of similar to 10(-5) B/B. present at mountaintop observatories with clear skies. This stray light level would allow spectroscopic differencing observations of visible coronal emission lines (similar to 4 x 10(-8) B/B. at 2R. for coronal green line features) well into the inner corona from a space-based platform. An aspheric mirror with better performance than this stray light has been installed in the LASCO flight instrument. We describe the scatterometer apparatus, detail the experimental results, and present a comparison between predicted coronagraph stray light levels and nominal coronal signal levels. (C) 1996 Society of Photo-Optical Instrumentation Engineers. C1 MAX PLANCK INST AERON,W-3411 KATLENBURG DUHM,GERMANY. RP Korendyke, CM (reprint author), USN,RES LAB,EO HULBURT CTR SPACE RES,CODE 7662K,4555 OVERLOOK AVE,WASHINGTON,DC 20375, USA. NR 16 TC 2 Z9 2 U1 0 U2 1 PU SOC PHOTO-OPT INSTRUM ENG PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD APR PY 1996 VL 35 IS 4 BP 1170 EP 1174 DI 10.1117/1.600949 PG 5 WC Optics SC Optics GA UE920 UT WOS:A1996UE92000040 ER PT J AU Pieper, RJ Richstein, JK Poon, TC Moore, DJ AF Pieper, RJ Richstein, JK Poon, TC Moore, DJ TI Real-time histogram generation using active optical scanning SO OPTICS AND LASER TECHNOLOGY LA English DT Article DE histogram generation; image processing; scanning; opto-electronics AB A prototype of an optical-electronic histogram generator has been designed and tested for one-dimensional objects. In this scheme, the object to be analysed is laser scanned. The resulting optical signal is detected by a photodetector, which generates an electrical signal output that is subsequently analysed with a combination of analogue and digital electronics. The system is shown to be fairly modular in design. Various aspects of the extension of the design to two dimensions are discussed. Copyright (C) 1996 Elsevier Science Ltd. C1 VIRGINIA POLYTECH INST & STATE UNIV,BRADLEY DEPT ELECT ENGN,OPT IMAGE PROC LAB,BLACKSBURG,VA 24061. RP Pieper, RJ (reprint author), USN,POSTGRAD SCH,DEPT ELECT & COMP ENGN,MONTEREY,CA 93943, USA. NR 13 TC 0 Z9 1 U1 0 U2 1 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0030-3992 J9 OPT LASER TECHNOL JI Opt. Laser Technol. PD APR PY 1996 VL 28 IS 3 BP 171 EP 178 DI 10.1016/0030-3992(95)00056-9 PG 8 WC Optics; Physics, Applied SC Optics; Physics GA UJ669 UT WOS:A1996UJ66900024 ER PT J AU OBrien, F Hammel, SE Nguyen, CT AF OBrien, F Hammel, SE Nguyen, CT TI Poisson ensembles in three dimensions SO PERCEPTUAL AND MOTOR SKILLS LA English DT Article AB The authors recently derived a method for assessing stochastic randomness in three dimensional Euclidean space. The method was derived from a nearest neighbor spatial Poisson process. An alternative probability model based on a box-counting method derived from a partial sum of a Poisson series is presented in this paper. The performance of the method is evaluated through Monte Carlo simulations with synthetically constructed random distributions. A comparison between the new discrete distribution method and the initial distance method showed that a greater likelihood of detecting randomness existed among populations with the box-counting method. RP OBrien, F (reprint author), USN,UNDERSEA WARFARE CTR DIV,CODE 2211,B1171-1,1176 HOWELL ST,NEWPORT,RI 02841, USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU PERCEPTUAL MOTOR SKILLS PI MISSOULA PA PO BOX 9229, MISSOULA, MT 59807 SN 0031-5125 J9 PERCEPT MOTOR SKILL JI Percept. Mot. Skills PD APR PY 1996 VL 82 IS 2 BP 579 EP 587 PG 9 WC Psychology, Experimental SC Psychology GA UF269 UT WOS:A1996UF26900040 ER PT J AU Adachi, K Yamashita, T Taneda, Y Farkas, DM Perkins, J AF Adachi, K Yamashita, T Taneda, Y Farkas, DM Perkins, J TI Dynamical transmission electron microscopy microstructure associated with electron-phonon interaction in high-damping Cu-Mn alloys SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID TWEED MICROSTRUCTURES; NI-AL; CONTRAST AB The transformation behaviour of Cu-Mn-based high damping alloys aged within a miscibility gap has been studied intensively using transmission electron microscopy (TEM), with particular attention to fine-scale dynamical movements in segregated microstructures, termed 'flickering'. As ageing proceeds, features appear in sequence in TEM images: mottled, tweed, and V-shaped images are observed in this order. The image contrast of these features, as well as streaks in diffraction patterns, and their extinctions, have been consistently explained by assuming a growth of the static displacement field of the {110}[<1(1)over bar0>] mode in the fee lattice, in agreement with other 'tweed-forming' materials. In addition, extra diffuse intensities due to {110}* relwalls in diffraction patterns are observed, which are considered to arise from a dynamic displacement wave of the {110}[<1(1)over bar0>] mode. Distinctive 'flickering' movements are observed at a stage of ageing corresponding to a transition from the late stage of 'tweed' to the 'V-shaped' stage, i.e., in the microstructure of highest-damping capability. The flickering movements are interpreted as a direct manifestation of the fcc reversible arrow fct transformation, with a rotation of the fct tetragonal axis taking place in Mn-enriched confined regions. This is driven by a [110][<1(1)over bar0>] phonon coupling and decoupling process under the inelastic interaction of the phonons with the accelerated electrons. A similar dynamical effect known as 'streaming' is separately observed, which is considered to be another manifestation of the electron-phonon interaction taking place in the Cu-rich matrix in this system. C1 USN,POSTGRAD SCH,MAT SCI GRP,MONTEREY,CA 93943. NATL DEF ACAD,DEPT PHYS,YOKOSUKA,KANAGAWA 239,JAPAN. MONTEREY INST ADV STUDIES,MONTEREY,CA 93943. RP Adachi, K (reprint author), SUMITOMO MET MIN CO,CENT RES LAB,ICHIKAWA,CHIBA 272,JAPAN. NR 34 TC 17 Z9 17 U1 1 U2 6 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD APR PY 1996 VL 73 IS 4 BP 1009 EP 1034 PG 26 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA UH918 UT WOS:A1996UH91800012 ER PT J AU CORREDOR, EL AF CORREDOR, EL TI A HISTORY OF MODERN CRITICISM, 1750-1950, VOL 7, GERMAN, RUSSIAN, AND EASTERN EUROPEAN CRITICISM, 1900-1950 - WELLEK,R SO PHILOSOPHY AND LITERATURE LA English DT Book Review RP CORREDOR, EL (reprint author), USN ACAD,ANNAPOLIS,MD 21402, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU JOHNS HOPKINS UNIV PRESS PI BALTIMORE PA JOURNALS PUBLISHING DIVISION, 2715 NORTH CHARLES ST, BALTIMORE, MD 21218-4319 SN 0190-0013 J9 PHILOS LITERATURE JI Philos. Lit. PD APR PY 1996 VL 20 IS 1 BP 259 EP 260 DI 10.1353/phl.1996.0030 PG 2 WC Literary Theory & Criticism; Literature SC Literature GA UK765 UT WOS:A1996UK76500034 ER PT J AU CORREDOR, EL AF CORREDOR, EL TI A HISTORY OF MODERN CRITICISM, 1750-1950, VOL 8, FRENCH, ITALIAN, AND SPANISH CRITICISM, 1900-1950 - WELLEK,R SO PHILOSOPHY AND LITERATURE LA English DT Book Review RP CORREDOR, EL (reprint author), USN ACAD,ANNAPOLIS,MD 21402, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU JOHNS HOPKINS UNIV PRESS PI BALTIMORE PA JOURNALS PUBLISHING DIVISION, 2715 NORTH CHARLES ST, BALTIMORE, MD 21218-4319 SN 0190-0013 J9 PHILOS LITERATURE JI Philos. Lit. PD APR PY 1996 VL 20 IS 1 BP 260 EP 262 DI 10.1353/phl.1996.0031 PG 3 WC Literary Theory & Criticism; Literature SC Literature GA UK765 UT WOS:A1996UK76500035 ER PT J AU Grunberg, P Wolf, JA Schafer, R AF Grunberg, P Wolf, JA Schafer, R TI Long-range exchange interactions in epitaxial layered magnetic structures SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 4th International Conference on Surface X-Ray and Neutron Scattering CY JUN, 1995 CL LAKE GENEVA, WI SP Argonne Natl Lab ID INTERLAYER EXCHANGE; GIANT MAGNETORESISTANCE; BIQUADRATIC EXCHANGE; CR INTERLAYERS; FE LAYERS; OSCILLATIONS; MULTILAYERS; SUPERLATTICES; MECHANISM; PERIOD AB Since the discovery of antiferromagnetic (AF) type interlayer coupling in 1986 numerous systems have been investigated. Generally, it is found that the coupling of ferromagnetic films separated by an interlayer oscillates as a function of the interlayer thickness between ferro (F)- and AF-type and the transition zones are characterized by 90 degrees-type coupling. The oscillation periods are in agreement with a theory that attributes the microscopic origin of the coupling to an indirect exchange of the ferromagnetic layers via the electrons of the interlayer. For the 90 degrees-type coupling various mechanisms have been proposed but the situation is still unclear. We would like to present here a condensed overview of the field and illustrate the development with some own results. C1 USN, RES LAB, WASHINGTON, DC 20375 USA. IFW DRESDEN, D-01171 DRESDEN, GERMANY. RP FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, IFF, EINSTEINSTR 34, D-52425 JULICH, GERMANY. NR 31 TC 3 Z9 3 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD APR PY 1996 VL 221 IS 1-4 BP 357 EP 365 DI 10.1016/0921-4526(95)00949-3 PG 9 WC Physics, Condensed Matter SC Physics GA UR277 UT WOS:A1996UR27700054 ER PT J AU Serpa, FG Meyer, ES Morgan, CA Gillaspy, JD Sugar, J Roberts, JR Brown, CM Feldman, U AF Serpa, FG Meyer, ES Morgan, CA Gillaspy, JD Sugar, J Roberts, JR Brown, CM Feldman, U TI Anomalous Z dependence of a magnetic dipole transition in the Ti I isoelectronic sequence SO PHYSICAL REVIEW A LA English DT Article ID DIRAC-FOCK; 2-ELECTRON IONS AB In isoelectronic sequences, transition wavelengths ordinarily move rapidly to shorter wavelengths as Z increases. However, it has been predicted that a particular sequence of magnetic dipole (M1) transition wavelengths for the Ti-like ions, Xe+32 through U+70, remain relatively constant in the 320-400-nm range. In the present paper we extend the experimental identifications of the Ti-like M1 transitions from Ba and Xe to Nd (Nd+38) and Gd (Gd+42) to verify this behavior. Using the newly acquired wavelengths to adjust atomic parameters, we have also calculated improved wavelengths for all such M1 transitions between Xe (Z=54) and Os (Z=76). C1 USN,RES LAB,EO HULBURT CTR SPACE RES,WASHINGTON,DC 20375. UNIV NOTRE DAME,NOTRE DAME,IN 46556. TEXAS A&M UNIV,COLLEGE STN,TX 77843. RP Serpa, FG (reprint author), NIST,DIV ATOM PHYS,GAITHERSBURG,MD 20899, USA. NR 17 TC 35 Z9 35 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR PY 1996 VL 53 IS 4 BP 2220 EP 2224 DI 10.1103/PhysRevA.53.2220 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA UE921 UT WOS:A1996UE92100046 ER PT J AU Pierson, SW Katona, TM Tesanovic, Z Valls, OT AF Pierson, SW Katona, TM Tesanovic, Z Valls, OT TI Critical fluctuations and lowest-Landau-level scaling of the specific heat of high-temperature superconductors SO PHYSICAL REVIEW B LA English DT Article ID II SUPERCONDUCTORS; MAGNETIC-FIELD; HC2 LINE; CAPACITY AB The specific heat data of various high-temperature superconducting materials at finite magnetic field and temperatures near the transition temperature are studied. It is found that lowest-landau-level (LLL) scaling is a good description of the data for fields larger than a characteristic field H*similar to 0(1 T) and that it breaks down for fields less than H*. The scaled data agrees very well with the calculated scaling functions, which provides further evidence for the validity of LLL theory at fields H greater than or equal to H*. The dimensionality of the fluctuations is also studied and it is found that they are predominantly three dimensional near the transition with indications of crossover to two-dimensional behavior farther away. C1 JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. UNIV MINNESOTA,SCH PHYS & ASTRON,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,MINNESOTA SUPERCOMP INST,MINNEAPOLIS,MN 55455. RP Pierson, SW (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 21 TC 33 Z9 33 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD APR 1 PY 1996 VL 53 IS 13 BP 8638 EP 8642 DI 10.1103/PhysRevB.53.8638 PG 5 WC Physics, Condensed Matter SC Physics GA UF063 UT WOS:A1996UF06300086 ER PT J AU Carroll, TL AF Carroll, TL TI Amplitude-independent chaotic synchronization SO PHYSICAL REVIEW E LA English DT Article ID SYSTEMS; CIRCUITS; SIGNALS AB There has recently been speculation on whether or not chaotic synchronization might be useful for communications. One problem with using chaotic synchronization to communicate is that the response system is nonlinear, so that any variation in the amplitude of the chaotic driving signal degrades the synchronization of the response system to the drive system. In the present work, I show that it is possible to design a response system that reproduces a scaled version of the chaotic driving signal when the drive signal is attenuated or amplified. A simple communications system is demonstrated to show that the type of synchronization described here is useful, and the effects of noise on the communications system are studied. RP USN, RES LAB, WASHINGTON, DC 20375 USA. OI Carroll, Thomas/0000-0002-2371-2049 NR 21 TC 16 Z9 16 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD APR PY 1996 VL 53 IS 4 BP 3117 EP 3122 DI 10.1103/PhysRevE.53.3117 PN A PG 6 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA UH481 UT WOS:A1996UH48100022 ER PT J AU Selinger, JV MacKintosh, FC Schnur, JM AF Selinger, JV MacKintosh, FC Schnur, JM TI Theory of cylindrical tubules and helical ribbons of chiral lipid membranes SO PHYSICAL REVIEW E LA English DT Article ID ORIENTATIONAL ORDER; BILAYER-MEMBRANES; CRYSTALLINE ORDER; MODULATED PHASES; LIQUID-CRYSTALS; MICROSTRUCTURES; 1,2-BIS(TRICOSA-10,12-DIYNOYL)-SN-GLYCERO-3-PHOSPHOCHOLINE; MICROSCOPY; BEHAVIOR; LECITHIN AB We present a general theory for the equilibrium structure of cylindrical tubules and helical ribbons of chiral lipid membranes. This theory is based on a continuum elastic free energy that permits variations in the direction of molecular tilt and in the curvature of the membrane. The theory shows that the formation of tubules and helical ribbons is driven by the chirality of the membrane. Tubules have a first-order transition from a uniform state to a helically modulated state, with periodic stripes in the tilt direction and ripples in the curvature. Helical ribbons can be stable structures or unstable intermediate states in the formation of tubules. C1 UNIV MICHIGAN, DEPT PHYS, ANN ARBOR, MI 48109 USA. RP USN, RES LAB, CTR BIOMOLEC SCI & ENGN, CODE 6900, 4555 OVERLOOK AVE SW, WASHINGTON, DC 20375 USA. RI Selinger, Jonathan/D-1445-2010; MacKintosh, Fred/A-9450-2008 OI Selinger, Jonathan/0000-0002-4982-2457; MacKintosh, Fred/0000-0002-2607-9541 NR 48 TC 141 Z9 142 U1 2 U2 22 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD APR PY 1996 VL 53 IS 4 BP 3804 EP 3818 DI 10.1103/PhysRevE.53.3804 PN B PG 15 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA UH482 UT WOS:A1996UH48200023 ER PT J AU Bulsara, AR Elston, TC Doering, CR Lowen, SB Lindenberg, K AF Bulsara, AR Elston, TC Doering, CR Lowen, SB Lindenberg, K TI Cooperative behavior in periodically driven noisy integrate-fire models of neuronal dynamics SO PHYSICAL REVIEW E LA English DT Article ID STOCHASTIC RESONANCE; FLUCTUATING BARRIER; TIME; INFORMATION AB The dynamics of the standard integrate-fire model and a simpler model (that reproduces the important features of the integrate-fire model under certain conditions) of neural dynamics are studied in the presence of a deterministic external driving force, taken to be time-periodic, and white background noise. Both models possess resonant phenomena in the first passage probability distribution and mean first passage time, arising from the interplay of characteristic time scales in the system. C1 LOS ALAMOS NATL LAB, CTR NONLINEAR STUDIES, LOS ALAMOS, NM 87545 USA. LOS ALAMOS NATL LAB, THEORET DIV, LOS ALAMOS, NM 87545 USA. COLUMBIA UNIV, DEPT ELECT ENGN, NEW YORK, NY 10027 USA. UNIV CALIF SAN DIEGO, DEPT CHEM & BIOCHEM B034, LA JOLLA, CA 92093 USA. RP USN, COMMAND CONTROL & OCEAN SURVEILLANCE CTR, RES DEV TEST & EVALUAT DIV, CODE 364, SAN DIEGO, CA 92152 USA. NR 60 TC 139 Z9 140 U1 0 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD APR PY 1996 VL 53 IS 4 BP 3958 EP 3969 DI 10.1103/PhysRevE.53.3958 PN B PG 12 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA UH482 UT WOS:A1996UH48200038 ER PT J AU Velikovich, A Phillips, L AF Velikovich, A Phillips, L TI Instability of a plane centered rarefaction wave SO PHYSICS OF FLUIDS LA English DT Article ID LASER AB An analytic small-amplitude theory of the instability of a plane centered rarefaction wave (which has recently been discovered numerically by Yang et al.(5)) is presented. A finite-difference (FCT) calculation is performed and compares well with the theory. The instability manifests itself as perturbation growth on the wave's trailing edge. The asymptotic value approached by the perturbed velocity of the trailing edge is expressed as k delta x(0)a(0)u(infinity)(M,gamma), where k is the perturbation wave number, delta x(0) is the constant perturbation amplitude of the leading edge, a(0) is the sound speed in the unperturbed gas, and u(infinity)(M,gamma) is a dimensionless function that depends on the adiabatic exponent, gamma, and the strength of the rarefaction wave, M, taken as the ratio of sound speeds behind and ahead of it. This function is essentially determined by the way the perturbed rarefaction wave is formed, e.g., by moving a corrugated piston from a gas-filled space or by interaction of a plane shock wave with a rippled contact interface between two different gases. The function u(infinity)(M,gamma) is shown to vanish in the limiting cases of strong and weak rarefaction waves, its asymptotic form in the latter case (M-->1) being u(infinity)(M,gamma)=[(gamma+1)(1-M)/(gamma-1)](1/2). This instability, which, for example, might develop in high-gain nuclear fusion pellets accelerated by laser beams, appears to be relatively harmless for these types of applications, since neither the perturbations of density and pressure at any given value of x/t, nor the integral integral(delta rho)dx taken over the width of the rarefaction wave increase in time. (C) 1996 American Institute of Physics. C1 USN,RES LAB,WASHINGTON,DC 20375. RP Velikovich, A (reprint author), BERKELEY SCHOLARS INC,SPRINGFIELD,VA 22150, USA. RI Velikovich, Alexander/B-1113-2009 NR 13 TC 17 Z9 17 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD APR PY 1996 VL 8 IS 4 BP 1107 EP 1118 DI 10.1063/1.868889 PG 12 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA UC218 UT WOS:A1996UC21800023 ER PT J AU Keskinen, MJ AF Keskinen, MJ TI Nonlinear evolution of a narrow stratified velocity shear layer SO PHYSICS OF PLASMAS LA English DT Article ID KELVIN-HELMHOLTZ INSTABILITY; MAGNETIZED PLASMA; POLOIDAL ROTATION; TURBULENCE; TRANSPORT; VORTEX AB The nonlinear evolution of the Kelvin-Helmholtz instability in a narrow stratified velocity-shear layer has been computed using numerical and analytical techniques. It is found that the Kelvin-Helmholtz instability develops, in the nonlinear regime, in a distinctly different manner in configuration an k space when finite temperature effects are included in the fluid approximation. Vortex generation is inhibited with the vortices becoming striated and anisotropic. In addition, large density and electric field fluctuations are produced in the nonlinear regime. (C) 1996 American Institute of Physics. RP Keskinen, MJ (reprint author), USN,RES LAB,DIV PLASMA PHYS,BEAM PHYS BRANCH,WASHINGTON,DC 20375, USA. NR 23 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD APR PY 1996 VL 3 IS 4 BP 1259 EP 1262 DI 10.1063/1.871750 PG 4 WC Physics, Fluids & Plasmas SC Physics GA UD445 UT WOS:A1996UD44500010 ER PT J AU Zukowski, ML Ash, K Klink, B Reid, D Messa, A AF Zukowski, ML Ash, K Klink, B Reid, D Messa, A TI Breast reduction under intravenous sedation: A review of 50 cases SO PLASTIC AND RECONSTRUCTIVE SURGERY LA English DT Article AB Breast reduction is a surgical procedure most commonly performed on an inpatient basis under general anesthesia. In the current climate of health care reform, we must evaluate such procedures to determine if there are alternate, less expensive, but equally safe means to perform them. Our purpose is to present our experience with 50 bilateral breast reductions performed under local anesthesia with intravenous sedation between October of 1991 and October of 1994. We have excluded bilateral reductions under 500 gm total, unilateral reductions, mastopexies, and gynecomastia procedures. Patients were sedated with intravenous Versed and fentanyl and a local solution consisting of marcaine, lidocaine, and 1:200,000 epinephrine. Intercostal blocks were not used routinely. Monitoring and sedation were performed by nonanesthesia personnel in 49 patients. There were no complications relating to the sedation or to the local solution. All reductions were performed by the inferior pedicle technique. The average patient age was 28.0 years (20 to 67 years). The average total breast tissue resected was 1372 gm (516 to 2948 gm), with 33 patients having resections greater than 1000 gm. Operative times averaged 3 hours (115 to 275 minutes). Forty-nine of the 50 patients tolerated the procedure with little to no recall. Twenty-eight patients were discharged on the same day as admission. One patient recalled some significant discomfort during parts of the procedure. All stated that they would again have the procedure performed under local anesthesia with intravenous sedation. Our conclusions are as follows: (1) Breast reduction can be performed safely and comfortably under local anesthesia with intravenous sedation. (2) Patients should be chosen on their acceptability as intravenous sedation candidates and not with regard to the amount of breast tissue removed. (3) There will be a subset of patients who can be discharged on the same day. RP Zukowski, ML (reprint author), USN,MED CTR,DEPT PLAST SURG,PORTSMOUTH,VA 23708, USA. NR 5 TC 8 Z9 8 U1 0 U2 0 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0032-1052 J9 PLAST RECONSTR SURG JI Plast. Reconstr. Surg. PD APR PY 1996 VL 97 IS 5 BP 952 EP 956 DI 10.1097/00006534-199604001-00010 PG 5 WC Surgery SC Surgery GA UB855 UT WOS:A1996UB85500010 PM 8618998 ER PT J AU Holman, RW Kavarnos, GJ AF Holman, RW Kavarnos, GJ TI A molecular dynamics investigation of the structural characteristics of amorphous and annealed poly(vinylidene fluoride) and vinylidene fluoride-trifluoroethylene copolymers SO POLYMER LA English DT Article DE poly(vinylidene fluoride); conformational analysis; molecular dynamics AB Molecular dynamics (MD) computations predict that the extent of gauche-character for poly(vinylidene fluoride) (PVDF) is greater than that of its 50 mol% copolymer with trifluoroethylene, at both high temperatures and after annealing. PVDF is enriched in gauche-conformations upon cooling whereas the copolymer is enriched in trans-conformations. The MD results are consistent with the experimental trends observed for these polymers. Published by Elsevier Science Ltd. C1 USN,UNDERSEA WARFARE CTR,NEW LONDON DETACHMENT,SUBMARINE SONAR DEPT,NEW LONDON,CT 06320. RP Holman, RW (reprint author), WESTERN KENTUCKY UNIV,DEPT CHEM,BOWLING GREEN,KY 42101, USA. NR 7 TC 12 Z9 12 U1 1 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0032-3861 J9 POLYMER JI Polymer PD APR PY 1996 VL 37 IS 9 BP 1697 EP 1701 DI 10.1016/0032-3861(96)83721-9 PG 5 WC Polymer Science SC Polymer Science GA UJ284 UT WOS:A1996UJ28400025 ER PT J AU Fedderly, JJ Lee, GF Ferragut, DJ Hartmann, B AF Fedderly, JJ Lee, GF Ferragut, DJ Hartmann, B TI Effect of monofunctional and trifunctional modifiers on a phase mixed polyurethane system SO POLYMER ENGINEERING AND SCIENCE LA English DT Article; Proceedings Paper CT 3rd International Conference on Polymer Characterization CY JAN, 1995 CL DENTON, TX SP Perkin Elmer Corp, Int Sci Fdn Washington AB The dynamic mechanical behavior of a phase mixed polyurethane system modified with trifunctional and monofunctional alcohols was investigated and compared with a typical polyurethane system with a difunctional alcohol. Of interest was verifying that the average functionality of the alcohol would determine the dynamic mechanical properties and not whether that functionality was achieved by an equimolar blend of trifunctional and monofunctional alcohols or by a purely difunctional alcohol. The base system consisted of poly(tetramethylene ether)glycol (PTMG) cued with 4,4'-diphenylmethane diisocyanate (MDI). The trifunctional alcohol was trimethylol propane (TMP). The monofunctional alcohol was decyl alcohol (DA). Samples with a typical difunctional alcohol, a,2-dimethyl-1,3-propanediol (DMPD), were prepared and their properties compared with those of the above samples. To a first approximation, the properties of TMP-DA modified polymers are identical to those of DMPD polymers of the same hard segment concentration. These results confirm our hypothesis that the dynamic properties obtained from a combination of a trifunctional alcohol with a monofunctional alcohol are essentially equivalent to those of a difunctional alcohol. RP Fedderly, JJ (reprint author), USN,CTR SURFACE WARFARE,SILVER SPRING,MD 20903, USA. NR 11 TC 5 Z9 5 U1 1 U2 2 PU SOC PLASTICS ENG INC PI BROOKFIELD CENTER PA 14 FAIRFIELD DR, BROOKFIELD CENTER, CT 06804-0403 SN 0032-3888 J9 POLYM ENG SCI JI Polym. Eng. Sci. PD APR PY 1996 VL 36 IS 8 BP 1107 EP 1113 DI 10.1002/pen.10503 PG 7 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA UH972 UT WOS:A1996UH97200014 ER PT J AU Stephens, MB AF Stephens, MB TI Gas gangrene - Potential for hyperbaric oxygen therapy SO POSTGRADUATE MEDICINE LA English DT Article ID CLOSTRIDIUM-PERFRINGENS; EXPERIENCE; INFECTION AB Clostridial myonecrosis (gas gangrene) is an uncommon sequela of traumatic injury. Infection with Clostridium perfringens in devitalized tissue is the most common cause. Wide surgical debridement and appropriate antibiotic therapy remain the standard of care. However, the addition of hyperbaric oxygen therapy to standard management has been shown to have a synergistic effect in reducing morbidity and mortality in both canine and murine models. Although no prospective human data are available, retrospective data indicate that concomitant hyperbaric oxygen therapy has resulted in a twofold reduction in mortality. Where feasible, hyperbaric oxygen therapy should routinely be incorporated into the treatment plan for gas gangrene. Primary care physicians are in a unique position not only to make an early diagnosis but also to have a central role in coordinating multidisciplinary care often needed for this potentially fatal infection. C1 USN,MED RES INST,BETHESDA,MD 20814. RP Stephens, MB (reprint author), NAVAL HOSP BREMERTON,DEPT FAMILY MED,BOONE RD,BREMERTON,WA 98312, USA. RI Stephens, Mark/A-2679-2015 NR 25 TC 16 Z9 16 U1 0 U2 1 PU MCGRAW HILL HEALTHCARE PUBLICATIONS PI MINNEAPOLIS PA 4530 WEST 77TH ST, MINNEAPOLIS, MN 55435-5000 SN 0032-5481 J9 POSTGRAD MED JI Postgrad. Med. PD APR PY 1996 VL 99 IS 4 BP 217 EP & PG 5 WC Medicine, General & Internal SC General & Internal Medicine GA UE389 UT WOS:A1996UE38900024 PM 8604409 ER PT J AU Pollin, I DeLeon, PH AF Pollin, I DeLeon, PH TI Integrated health delivery systems: Psychology's potential role SO PROFESSIONAL PSYCHOLOGY-RESEARCH AND PRACTICE LA English DT Editorial Material C1 UNIV FLORIDA,HLTH SCI CTR,GAINESVILLE,FL 32611. RP Pollin, I (reprint author), USN,WASHINGTON,DC 20350, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AMER PSYCHOLOGICAL ASSOC PI WASHINGTON PA 750 FIRST ST NE, WASHINGTON, DC 20002-4242 SN 0735-7028 J9 PROF PSYCHOL-RES PR JI Prof. Psychol.-Res. Pract. PD APR PY 1996 VL 27 IS 2 BP 107 EP 108 PG 2 WC Psychology, Multidisciplinary SC Psychology GA UC412 UT WOS:A1996UC41200001 ER PT J AU Griffin, SR Grosz, FB Richardson, MD AF Griffin, SR Grosz, FB Richardson, MD TI In situ sediment geoacoustic measurement system SO SEA TECHNOLOGY LA English DT Article C1 USN,RES LAB,COASTAL BENTH BOUNDARY LAYER PROGRAM,BAY ST LOUIS,MS. RP Griffin, SR (reprint author), OMNI TECHNOL INC,KENNER,LA, USA. NR 0 TC 7 Z9 12 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD APR PY 1996 VL 37 IS 4 BP 19 EP 22 PG 4 WC Engineering, Ocean SC Engineering GA UG070 UT WOS:A1996UG07000004 ER PT J AU Martin, RL Weinberg, H AF Martin, RL Weinberg, H TI Beacon navigation in shallow water SO SEA TECHNOLOGY LA English DT Article C1 USN,UNDERSEA WAFFARE CTR DIV,WEAP ANAL FACIL,NEWPORT,RI 02840. RP Martin, RL (reprint author), USN,METEOROL & OCEANOL COMMAND,STENNIS SPACE SCI,MS, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD APR PY 1996 VL 37 IS 4 BP 57 EP 62 PG 6 WC Engineering, Ocean SC Engineering GA UG070 UT WOS:A1996UG07000013 ER PT J AU Geiger, ML AF Geiger, ML TI Bioluminescence - Opportunity for passive surveillance SO SEA TECHNOLOGY LA English DT Article RP Geiger, ML (reprint author), USN,OCEANOG OFF,BAY ST LOUIS,MS, USA. NR 4 TC 0 Z9 0 U1 1 U2 1 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD APR PY 1996 VL 37 IS 4 BP 69 EP & PG 4 WC Engineering, Ocean SC Engineering GA UG070 UT WOS:A1996UG07000016 ER PT J AU Mioc, SL Garland, JW Bennett, BR AF Mioc, SL Garland, JW Bennett, BR TI Charge trapping and built-in field studies in electroreflectance of a UN+ GaAs structure SO SEMICONDUCTOR SCIENCE AND TECHNOLOGY LA English DT Article ID SURFACE FERMI LEVEL; PHOTOREFLECTANCE; REGION AB A form of contactless electroreflectance, vacuum electroreflectance (VER), is used to quantitatively compare photoreflectance (PR) with electroreflectance (ER). It is found that the amplitude of the VER signal for a given applied modulation taken under CW laser illumination drastically decreases with increasing laser intensity, This new effect is studied as a function of frequency, and is explained in terms of the screening of the a.c. applied field by the surface charge, due to the presence of extra charge carriers in the depletion region. This effect is not present in contact forms of ER. It is also shown from a systematic comparison of PR and VER data that even for the lowest laser intensities which give an observable PR signal, the nature of the modulation in PR lowers the measured built-in field by an amount well outside the uncertainties in the determination of the field. C1 UNIV ILLINOIS,CHICAGO,IL 60607. USN,RES LAB,WASHINGTON,DC 20375. RI Bennett, Brian/A-8850-2008 OI Bennett, Brian/0000-0002-2437-4213 NR 12 TC 6 Z9 6 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0268-1242 J9 SEMICOND SCI TECH JI Semicond. Sci. Technol. PD APR PY 1996 VL 11 IS 4 BP 521 EP 524 DI 10.1088/0268-1242/11/4/010 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA UE589 UT WOS:A1996UE58900009 ER PT J AU Satyanarayana, A Wood, RK Camarinopoulos, L Pampoukis, G AF Satyanarayana, A Wood, RK Camarinopoulos, L Pampoukis, G TI A linear-time algorithm for computing K-terminal reliability in a series-parallel network - Note SO SIAM JOURNAL ON COMPUTING LA English DT Article DE algorithms; complexity; network reliability; series-parallel graphs; reliability-preserving reductions C1 USN,POSTGRAD SCH,DEPT OPERAT RES,MONTEREY,CA 93943. ARISTOTELIAN UNIV THESSALONIKI,SCH ENGN,GR-54006 THESSALONIKI,GREECE. RP Satyanarayana, A (reprint author), STEVENS INST TECHNOL,DEPT PURE & APPL MATH,HOBOKEN,NJ 07030, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER PH#382-9800, PHILADELPHIA, PA 19104-2688 SN 0097-5397 J9 SIAM J COMPUT JI SIAM J. Comput. PD APR PY 1996 VL 25 IS 2 BP 290 EP 290 DI 10.1137/S0097539793257988 PG 1 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA UC926 UT WOS:A1996UC92600004 ER PT J AU Merzbacher, CI Kersey, AD Friebele, EJ AF Merzbacher, CI Kersey, AD Friebele, EJ TI Fiber optic sensors in concrete structures: A review SO SMART MATERIALS & STRUCTURES LA English DT Review ID STRAIN-SENSOR; FILTER; SYSTEM AB Fiber optic sensors (FOSs) are ideally suited for monitoring strain in concrete structures due to their small size, low cost, ability to be embedded internally, and multiplexing capabilities. Several types of fiber optic strain sensor have been developed, including those based on intensity, polarization, interferometry, and fiber Bragg gratings (FBGs). The FBGs have the advantage of being absolute, linear in response, interrupt immune, and most readily multiplexed. The ability of embedded and surface mounted FOSs to detect strain in reinforced concrete has been demonstrated in several laboratory tests. Comparisons between various FOSs and traditional foil strain gages show good agreement. Sensors have been surface mounted on existing bridges to evaluate observed cracking and to monitor vibration due to traffic loading. FOSs have also been embedded in several newly constructed civil structures, including bridges, buildings, and dams, yielding information about static and dynamic strain, temperature, wind or water pressure, and structural health. Practical and logistical challenges to routine implementation of FOSs in civil structures are being addressed with each additional application. C1 USN, RES LAB, DIV OPT SCI, WASHINGTON, DC 20375 USA. NR 57 TC 134 Z9 143 U1 9 U2 42 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD APR PY 1996 VL 5 IS 2 BP 196 EP 208 DI 10.1088/0964-1726/5/2/008 PG 13 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA UL969 UT WOS:A1996UL96900008 ER PT J AU Nisenoff, M AF Nisenoff, M TI The high-temperature superconductivity space experiment (HTSSE): Present status and future challenges SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article; Proceedings Paper CT 5th International Superconductive Electronics Conference (ISEC 95) CY SEP 18-21, 1995 CL NAGOYA, JAPAN AB The high-temperature superconductivity space experiment (HTSSE) at the Naval Research Laboratory (NRL) is exploring the feasibility of deploying high-temperature superconducting (HTS) electronic devices, components and subsystems in space. The initial HTSSE experiment, which employed HTS technology available in 1990, focused on simple microwave devices which were suitably packaged, integrated with a cryogenic refrigerator and built into a space-qualified payload. Unfortunately the HTSSE-1 payload, which was launched in 1993, did not achieve orbit and was lost. The second HTSSE experiment, HTSSE-II, which will use HTS technology circa 1993-94, will consist of complex HTS components and hybrid subsystems consisting of HTS and conventional semiconductor components, the latter operating either at cryogenic temperature or at ambient temperature. The HTSSE-II payload containing the HTS components, cryogenic refrigerator and monitoring electronics will have been built, space qualified and shipped from NRL in November 1995 to the satellite integrator for a planned Summer 1996 launch. A description of the HTSSE-II payload will be presented and the performance of the HTS components and their potential impact on future space communications systems will be described. RP Nisenoff, M (reprint author), USN,RES LAB,ELECTR SCI & TECHNOL DIV,MICROWAVE TECHNOL BRANCH,WASHINGTON,DC 20375, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD APR PY 1996 VL 9 IS 4A BP A174 EP A177 DI 10.1088/0953-2048/9/4A/044 PG 4 WC Physics, Applied; Physics, Condensed Matter SC Physics GA UF346 UT WOS:A1996UF34600044 ER PT J AU Madhavan, V Farris, TN Chandrasekar, S Craig, L AF Madhavan, V Farris, TN Chandrasekar, S Craig, L TI FEM comparison of ball and roller bullgears SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT 50th Annual Meeting of STLE CY MAY 14-19, 1995 CL CHICAGO, IL SP STLE DE rolling-element bearings; contact mechanics; stress analysis ID NEGLECTING FRICTION; LOAD DISTRIBUTION; EQUILIBRIUM; 5-DEGREES; BEARINGS; FREEDOM AB A structural finite element model has been developed for calculating the forces transmitted through the rolling elements (fond distribution) in a bullgear assembly. The elastic structural model consists of 3-D beam elements used to approximate the global race deflection. and non-linear springs that approximate the combined rolling element/raceway contact deflections. For rollers, an upperbound on the contact stress (assuming linear variation of force along the length of the roller) is estimated by modeling the rollers as pairs of nonlinear springs. The finite element approach iteratively solves the Contact forces al each rolling element. Contact stresses are then calculated from the contact forces using Hertz contact theory. This approach is applied to analyze two Proposed designs of hall and crossed roller hearing bullgear assemblies used for relating the radar antenna on top of a ship's mast. The lends analyzed include those arising from wind lending and from out-of-flatness of the inner race of the bearings due to deflection of the mast. The distribution of the load and the maximum contact stresses for the proposed bullgear assemblies are estimated and compared. It is found that the maximum contact stress in the crossed roller bearing is less than that in the ball bearing for both types of loads. Furthermore, the analysis shows that the out-of-flatness loading produces significantly higher stresses than wind loading. C1 USN,CTR SURFACE WARFARE,CRANE,IN 47522. RP Madhavan, V (reprint author), PURDUE UNIV,W LAFAYETTE,IN 47907, USA. RI yang, lin/G-6662-2011 NR 15 TC 1 Z9 1 U1 0 U2 1 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 838 BUSSE HIGHWAY, PARK RIDGE, IL 60068 SN 0569-8197 J9 TRIBOL T JI Tribol. Trans. PD APR PY 1996 VL 39 IS 2 BP 286 EP 295 DI 10.1080/10402009608983530 PG 10 WC Engineering, Mechanical SC Engineering GA UB372 UT WOS:A1996UB37200007 ER PT J AU Collins, GE Buckley, LJ AF Collins, GE Buckley, LJ TI Conductive polymer-coated fabrics for chemical sensing SO SYNTHETIC METALS LA English DT Article DE fabric; sensors; dimethyl methylphosphonate; polypyrrole ID PATTERN-RECOGNITION; VAPOR DETECTION; ORGANIC VAPORS; WORK FUNCTION; SENSOR; POLY(PYRROLE); POLYPYRROLE AB A novel sensing format for the detection of toxic vapors is presented. It uses thin films of conductive polymers, polypyrrole or polyaniline, coated onto poly(ethylene terephthalate) or nylon threads woven into a fabric mesh. Chemical sensing on fabrics offers the opportunity of using the large surface area for improved sensitivity and expanded dynamic range. The resistivity of these materials was monitored following exposure to several toxic gases. Detection limits in parts per million (ppm) were demonstrated for various pollutants and chemical warfare simulants, including dimethyl methylphosphonate (DMMP), ammonia, and nitrogen dioxide. The effect of humidity on the detection capabilities of these materials was also characterized. Polymeric overcoats including polyethylenimine and fluoropolyol were evaluated as a means of introducing selectivity and sensitivity with respect to the adsorption of particular classes of gas analytes. RP Collins, GE (reprint author), USN,RES LAB,DIV CHEM,CODE 6125,WASHINGTON,DC 20375, USA. NR 21 TC 135 Z9 138 U1 5 U2 44 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD MAR 30 PY 1996 VL 78 IS 2 BP 93 EP 101 DI 10.1016/0379-6779(96)80108-1 PG 9 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA UP883 UT WOS:A1996UP88300001 ER PT J AU Boos, JB Kruppa, W Park, D Molnar, B Bennett, BR AF Boos, JB Kruppa, W Park, D Molnar, B Bennett, BR TI AlSb/InAs HEMTs with high transconductance and negligible kink effect SO ELECTRONICS LETTERS LA English DT Article DE ohmic contracts; field effect transistors; high electron mobility transistors AB AlSb/lnAs HEMTs with a 200nm gate length have been fabricated and exhibit a low-field source-drain resistance of 0.6 Omega mm, a transconductance as high as 1.3S/mm, and an effective electron velocity of 3.5 x 10(7)cm/s. The HEMTs also have a negligible kink effect. C1 SFA INC,LANDOVER,MD 20785. RP Boos, JB (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Bennett, Brian/A-8850-2008 OI Bennett, Brian/0000-0002-2437-4213 NR 4 TC 12 Z9 12 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD MAR 28 PY 1996 VL 32 IS 7 BP 688 EP 689 DI 10.1049/el:19960408 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA UL773 UT WOS:A1996UL77300058 ER PT J AU Sarkas, HW Kwan, W Flom, SR Merritt, CD Kafafi, ZH AF Sarkas, HW Kwan, W Flom, SR Merritt, CD Kafafi, ZH TI Enhanced photooxidative stability of conjugated polymers via C-60 Doping SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Letter AB The effect of C-60 doping on the photooxidative stability of the conjugated polymer poly [2-methoxy-5-(2'-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) is investigated via Fourier transform infrared and ultraviolet-visible absorption spectroscopies. The photooxidation of both MEH-PPV and MEH-PPV/C-60 exhibits first-order kinetics. Analysis reveals that C-60 slows the rate of photodegradation of MEH-PPV by more than an order of magnitude. C1 USN,RES LAB,OPT PHYS BRANCH,WASHINGTON,DC 20375. NR 22 TC 31 Z9 31 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 28 PY 1996 VL 100 IS 13 BP 5169 EP 5171 DI 10.1021/jp960322i PG 3 WC Chemistry, Physical SC Chemistry GA UC398 UT WOS:A1996UC39800005 ER PT J AU Dunlap, BI Doyle, RJ AF Dunlap, BI Doyle, RJ TI Ammonium nitrate cluster ions SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID DENSITY-FUNCTIONAL THEORY; GAS-PHASE; EXCHANGE-ENERGY; APPROXIMATION; ASSOCIATION; GEOMETRIES; COMPLEXES; ACCURATE; SYSTEMS AB Sputtering of condensed-phase ammonium nitrate yields many positive and negative cluster ion series derived from different ionic cores. The cluster cores are surrounded by varying numbers of ammonium nitrate monomer units. Most interesting is the extensive series of negative cluster ions of the form [(NH4NO3)(n)NO3](-), n greater than or equal to 3. The corresponding positive clusters, [(NH4NO3)(n)NH4](+), are also very extensive but also include the smallest ions, n = 1 and 2. Collision-induced dissociation of mass-selected cluster ions suggests that the first two members of the negative series, n = 1 and n = 2, are not detected because they rearrange and lose one or more ammonia molecules. Gradient-density-functional calculations using two different functionals predict that NH4NO3 is strongly hydrogen bonded and that [(NH4NO3)NO3](-) has no hydrogen bonds. This is consistent with this ion rearranging by loss of NH3 to form the strongly hydrogen-bonded ion [H(NO3)(2)](-). Rearrangements involving loss of ammonia molecules in the negative-ion spectrum and nitric acid molecules in the positive-ion spectrum lead to a rich variety of other, less extensive, series of sputtered ions from this complex solid. Both relative gradient-density-functional energies correlate well with whether or not various ions are observable experimentally. RP Dunlap, BI (reprint author), USN,RES LAB,DIV CHEM,CODE 6100,WASHINGTON,DC 20375, USA. OI Dunlap, Brett/0000-0003-1356-6559 NR 41 TC 9 Z9 9 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 28 PY 1996 VL 100 IS 13 BP 5281 EP 5285 DI 10.1021/jp9516755 PG 5 WC Chemistry, Physical SC Chemistry GA UC398 UT WOS:A1996UC39800019 ER PT J AU RamMohan, LR Meyer, JR Xie, H Wang, WI AF RamMohan, LR Meyer, JR Xie, H Wang, WI TI Normal incidence second-harmonic generation in L-valley AlSb/GaSb/Ga1-xAlxSb/AlSb stepped quantum wells - Response SO APPLIED PHYSICS LETTERS LA English DT Letter C1 COLUMBIA UNIV,DEPT ELECT ENGN,NEW YORK,NY 10027. USN,RES LAB,WASHINGTON,DC 20375. RP RamMohan, LR (reprint author), WORCESTER POLYTECH INST,WORCESTER,MA 01609, USA. RI Ram-Mohan, Ramdas/C-5167-2012 NR 3 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 25 PY 1996 VL 68 IS 13 BP 1873 EP 1873 DI 10.1063/1.116126 PG 1 WC Physics, Applied SC Physics GA UB535 UT WOS:A1996UB53500045 ER PT J AU Cho, G Natansohn, A Ho, T Wynne, KJ AF Cho, G Natansohn, A Ho, T Wynne, KJ TI Phase structure of poly(dimethylsiloxane-urea-urethane)segmented copolymers as observed by solid-state nuclear magnetic resonance spectra SO MACROMOLECULES LA English DT Article ID NMR AB Three segmented copolymers having as hard segments poly(urethane-urea)s based on isophorone diisocyanate (IF) and 1,4-benzenedimethanol (B) and having as soft segments poly (dimethylsiloxane)s (PDMS) of three different molecular weights are analyzed by CP-MAS C-13-NMR. Comparison of cross-polarized and non-cross-polarized spectra, together with proton relaxation measurements, establishes the presence of separated phases and differences in their mobility. The T-1p(H)'s and static H-1-NMR half-height line widths of PDMSyK-IP-B-2 (y = 2.4, 10, and 27; refers to the PDMS molecular weight) give information about the motion as a function of the molecular weight of PDMS. A dipolar filter sequence is employed to estimate the size of the dispersed hard phases, which appears to be of about 5 nm for all samples. The overall (soft and hard) domain sizes increase with the increase of silicone molecular weights, as expected. C1 QUEENS UNIV,DEPT CHEM,KINGSTON,ON K7L 3N6,CANADA. GEORGE MASON UNIV,DEPT CHEM,FAIRFAX,VA 22030. OFF NAVAL RES,PHYS SCI S&T DIV 331,ARLINGTON,VA 22217. USN,RES LAB,PHYS MAT LAB,WASHINGTON,DC 20375. NR 18 TC 29 Z9 29 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAR 25 PY 1996 VL 29 IS 7 BP 2563 EP 2569 DI 10.1021/ma950777q PG 7 WC Polymer Science SC Polymer Science GA UC286 UT WOS:A1996UC28600033 ER EF