FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Palmer, CEA AF Palmer, CEA TI Yucca Mountain site characterization project. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 30-NUCL BP U1036 EP U1036 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903095 ER PT J AU Palmer, PD Miller, GG AF Palmer, PD Miller, GG TI Quantitative analysis of selected RCRA metals using electrochemical techniques. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 31-TECH BP U383 EP U383 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901146 ER PT J AU Park, J Henins, I Selwyn, GS Jeong, JY Tu, V Hicks, RF AF Park, J Henins, I Selwyn, GS Jeong, JY Tu, V Hicks, RF TI Etching of refractory metals using a novel atmospheric pressure plasma. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Plasma Phys Grp, Los Alamos, NM 87545 USA. Univ Calif Los Angeles, Dept Chem Engn, Los Angeles, CA 90095 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 182-NUCL BP U1082 EP U1082 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903247 ER PT J AU Peden, CHF Su, YL Daschbach, JL Fryberger, TB Wang, Y Henderson, MA AF Peden, CHF Su, YL Daschbach, JL Fryberger, TB Wang, Y Henderson, MA TI Ionizing radiation-induced catalysis on metal-oxide particles. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 63-NUCL BP U1046 EP U1046 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903128 ER PT J AU Peterka, DS Ahmed, M Suits, AG AF Peterka, DS Ahmed, M Suits, AG TI Probing metastable O-4* with velocity map imaging. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 201-PHYS BP U331 EP U331 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034000926 ER PT J AU Peterka, DS Ahmed, M Ng, C Suits, AG AF Peterka, DS Ahmed, M Ng, C Suits, AG TI Imaging studies utilizing synchrotron radiation at the advanced light source. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Iowa State Univ, Ames Nat Lab, Ames, IA 50011 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 200-PHYS BP U330 EP U330 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034000925 ER PT J AU Pfohl, J AF Pfohl, J TI Techniques in nuclear spectroscopy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 157-NUCL BP U1074 EP U1074 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903222 ER PT J AU Piccoli, PMB Abney, KD Schoonover, JR Dorhout, PK AF Piccoli, PMB Abney, KD Schoonover, JR Dorhout, PK TI Synthesis, structure, and physical properties of quaternary F-element selenophosphates A(M)M(N)P(X)SE(Y) (A = K, Rb, CS; M = Th-232, Pu-239). SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, NMT, DO, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 88-INOR BP U737 EP U737 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033902223 ER PT J AU Pizarro, SA Fernandez, C Visser, H Armstrong, WH Wieghardt, K Girerd, JJ Yachandra, VK Sauer, KH Klein, MP AF Pizarro, SA Fernandez, C Visser, H Armstrong, WH Wieghardt, K Girerd, JJ Yachandra, VK Sauer, KH Klein, MP TI X-ray absorption spectroscopy of manganese model compounds with relevance to the photosystem II oxygen-evolving complex: Characterization of the Mn-Cl interaction. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Boston Coll, Dept Chem, Chestnut Hill, MA 02167 USA. Max Planck Inst Strahlenchem, D-4330 Mulheim, Germany. Univ Paris Sud, Lab Spectrochim Elements Transit, Orsay, France. RI Wieghardt, Karl/B-4179-2014; Institute of Chemistry - USP, Dept. of Chemistry/B-8988-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 493-INOR BP U859 EP U859 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033902605 ER PT J AU Place, I Penner, T Whitten, D AF Place, I Penner, T Whitten, D TI Layered nanocomposites of aggregated dyes end inorganic scaffolding. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Rochester, Ctr Photoinduced Charge Transfer, Rochester, NY 14627 USA. Eastman Kodak Co, Rochester, NY 14650 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 375-PHYS BP U379 EP U379 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034001095 ER PT J AU Pomes, R AF Pomes, R TI Theoretical studies of the Grotthuss mechanism in membrane proteins. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 79-COMP BP U500 EP U500 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901520 ER PT J AU Ponder, SM Schrick, B Kovtyukhova, NI Darab, JG Mallouk, TE AF Ponder, SM Schrick, B Kovtyukhova, NI Darab, JG Mallouk, TE TI Ferragels: Supported zero-valent iron as a remediant for aqueous metal ion wastes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Penn State Univ, Dept Chem, University Pk, PA 16802 USA. Pacific NW Lab, Dept Mat Sci, Richland, WA 99352 USA. RI Mallouk, Thomas/K-7391-2012 OI Mallouk, Thomas/0000-0003-4599-4208 NR 0 TC 0 Z9 0 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 206-NUCL BP U1089 EP U1089 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903271 ER PT J AU Pruski, M Wiench, JW Tischendorf, B Otaigbe, J AF Pruski, M Wiench, JW Tischendorf, B Otaigbe, J TI Characterization of connectivities between PO4 units in zinc phosphate glasses by nuclear magnetic resonance. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 52-GEOC BP U660 EP U661 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901996 ER PT J AU Rai, DP Rao, LF Felmy, AR Hess, NJ AF Rai, DP Rao, LF Felmy, AR Hess, NJ TI Measuring and modeling the solubility of Cr(III) compounds in concentrated NaOH and NaOH/NaNo3 solutions: Application to pretreatment of high-level waste sludges. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Pacific NW Lab, Environm & Hlth Sci Div, Richland, WA 99352 USA. Lawrence Berkeley Lab, Berkeley, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 202-NUCL BP U1088 EP U1088 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903267 ER PT J AU Rao, LF AF Rao, LF TI Join the division of nuclear chemistry and technology. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 40-NUCL BP U1039 EP U1039 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903105 ER PT J AU Ray, D AF Ray, D TI Ion complexants at liquid interfaces studied by nonlinear laser spectroscopy. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 117-ANYL BP U161 EP U161 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033900429 ER PT J AU Reinsch, V Greenberg, A Kelley, SS Krantz, W AF Reinsch, V Greenberg, A Kelley, SS Krantz, W TI Effect of cross-linking on compaction and performance of cellulose acetate membranes during high-pressure gas separation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Colorado, Golden, CO 80401 USA. NREL, Golden, CO 80401 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 1-MACR BP U706 EP U706 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034002135 ER PT J AU Ressler, JJ Walters, WB Wiescher, M Aprahamian, A AF Ressler, JJ Walters, WB Wiescher, M Aprahamian, A TI Half-life measurement for the rp-process waiting point nuclide Zr-80. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Maryland, Argonne Natl Lab, Argonne, IL 60439 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 159-NUCL BP U1075 EP U1075 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903224 ER PT J AU Rillema, DP Ferrere, S Shan, BZ AF Rillema, DP Ferrere, S Shan, BZ TI Photophysical and electron photoinjection properties of ruthenium(II) complexes containing bipyridine ligands with attached carboxyl groups. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Wichita State Univ, Dept Chem, Wichita, KS 67260 USA. Natl Renewable Energy Lab, Ctr Basic Sci, Golden, CO 80401 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 124-INOR BP U748 EP U749 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033902256 ER PT J AU Robinson, JM Foster, LL Wilson, KR Smilowitz, LB Casson, JL Dubey, MK Johal, MS Wilson, BF AF Robinson, JM Foster, LL Wilson, KR Smilowitz, LB Casson, JL Dubey, MK Johal, MS Wilson, BF TI Capillary absorption of methane on model Titan ices: Implications for a hidden hydrocarbon ocean. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Dept Chem & Biochem, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RI Dubey, Manvendra/E-3949-2010 OI Dubey, Manvendra/0000-0002-3492-790X NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 290-PHYS BP U356 EP U356 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034001013 ER PT J AU Rothenberger, KS Cugini, AV Siriwardane, RV Martello, DV Poston, JA Fisher, EP Graham, WJ Balachandran, U Dorris, SE AF Rothenberger, KS Cugini, AV Siriwardane, RV Martello, DV Poston, JA Fisher, EP Graham, WJ Balachandran, U Dorris, SE TI Performance testing of hydrogen transport membranes at elevated temperatures and pressures. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US DOE, Fed Energy Technol Ctr, Fuels & Chem Div, Pittsburgh, PA 15236 USA. US DOE, Gaseous Fuels & Gas Cleanup Div, Fed Energy Techol Ctr, Morgantown, WV 26507 USA. US DOE, Fed Energy Technol Ctr, Combust & Cleanup Div, Pittsburgh, PA 15236 USA. Parsons Infrastruct & Technol, Fed Energy Technol Ctr, Library, PA 15129 USA. Argonne Natl Lab, Ceram Sect, Div Energy Technol, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 106-FUEL BP U634 EP U635 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901920 ER PT J AU Rundberg, RS Fowler, MM Haight, RC Miller, GG Palmer, PD Seabury, EH Ullmann, JL Wilhelmy, JB Koehler, P Kappeler, F AF Rundberg, RS Fowler, MM Haight, RC Miller, GG Palmer, PD Seabury, EH Ullmann, JL Wilhelmy, JB Koehler, P Kappeler, F TI Neutron capture cross section measurements for the analysis of the S-process. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 98-NUCL BP U1056 EP U1056 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903163 ER PT J AU Russ, WR Valentine, JD Stuenkel, DO Gross, KC AF Russ, WR Valentine, JD Stuenkel, DO Gross, KC TI Performance evaluation of a fluid-based heavy noble gbs concentration system. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Georgia Inst Technol, Nucl & Radiol Engn Program, Neely Nucl Res Ctr, Atlanta, GA 30332 USA. Univ Cincinnati, Nucl & Radiol Engn Program, Dept MINE, Cincinnati, OH 45221 USA. Argonne Natl Lab, Reactor Anal Div, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 57-NUCL BP U1044 EP U1044 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903122 ER PT J AU Russo, RE Borisov, OV Mao, XL AF Russo, RE Borisov, OV Mao, XL TI Improving direct characterization of solid-waste forms using laser ablation with inductively coupled plasma mass spectrometry. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 147-NUCL BP U1072 EP U1072 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903212 ER PT J AU Rustad, JR Wiley, WR AF Rustad, JR Wiley, WR TI Molecular simulation of the magnetite(FE3O4)-water interface. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Pacific NW Lab, EMSL, Richland, WA 99352 USA. MentorGraphics, Wilsonville, OR 97070 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 36-COLL BP U410 EP U410 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901230 ER PT J AU Sachleben, RA Moyer, BA Bryan, JC Haverlock, TJ Engel, NL Franconville, B Urvoas, A AF Sachleben, RA Moyer, BA Bryan, JC Haverlock, TJ Engel, NL Franconville, B Urvoas, A TI Calix[4]arene crown-6 ethers: Recent developments in enhanced cesium-selective extractants. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Chem Separat Grp, Oak Ridge, TN 37831 USA. RI Solominow, Sonia/A-4021-2008; Moyer, Bruce/L-2744-2016 OI Moyer, Bruce/0000-0001-7484-6277 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 109-NUCL BP U1060 EP U1060 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903174 ER PT J AU Saljoughian, M Morimoto, H Williams, PG AF Saljoughian, M Morimoto, H Williams, PG TI Synthesis of high specific activity 3H-labeled nucleosides and nucleotides. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract ID 5'-TRIPHOSPHATES C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Tritium Labelling Facil, Phys Biosci Div, Berkeley, CA 94720 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 7-MEDI BP U911 EP U911 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033902760 ER PT J AU Salmeron, M AF Salmeron, M TI Structure and friction of boundary lubricants under confinement. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 159-COLL BP U445 EP U445 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901352 ER PT J AU Samet, AV Marshalkin, VN Semenov, VV Buchanan, AC Gakh, AA AF Samet, AV Marshalkin, VN Semenov, VV Buchanan, AC Gakh, AA TI Synthesis and chemical transformations of some nitrobenzoazoles. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 ND Zelinskii Organ Chem Inst, Moscow 117913, Russia. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 47-ORGN BP U21 EP U21 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034000048 ER PT J AU Savina, M Wang, Y Xu, ZY Reed, C Pellin, M AF Savina, M Wang, Y Xu, ZY Reed, C Pellin, M TI Analysis and decontamination of concrete by laser ablation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Technol Dev Div, Argonne, IL 60439 USA. RI Pellin, Michael/B-5897-2008 OI Pellin, Michael/0000-0002-8149-9768 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 148-NUCL BP U1072 EP U1072 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903213 ER PT J AU Schenter, GK Garrett, BC Ray, D Daschbach, JL AF Schenter, GK Garrett, BC Ray, D Daschbach, JL TI Transport of small molecules across the liquid-vapor interface of water. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RI Garrett, Bruce/F-8516-2011; Schenter, Gregory/I-7655-2014 OI Schenter, Gregory/0000-0001-5444-5484 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 427-PHYS BP U394 EP U394 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034001144 ER PT J AU Schreckenbach, G Ruiz-Morales, Y Wolff, SK Khandogin, J Ziegler, T Patchkovskii, S AF Schreckenbach, G Ruiz-Morales, Y Wolff, SK Khandogin, J Ziegler, T Patchkovskii, S TI GIAO-DFT approach to the calculation of NMR and EPR parameters: Quanitative results and qualitative interpretations. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calgary, Calgary, AB T2N 1N4, Canada. RI Ziegler, Tom/D-7863-2012 NR 0 TC 1 Z9 1 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 170-PHYS BP U322 EP U322 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034000897 ER PT J AU Seaman, JC Bertsch, PM AF Seaman, JC Bertsch, PM TI In situ radionuclide stabilization: Scientific basis for minimally invasive treatment techniques. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Aiken, SC 29802 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 101-NUCL BP U1057 EP U1057 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903166 ER PT J AU Seeck, OH Sinha, SK Rafailovich, M Sokolov, J Shin, K Tolan, M AF Seeck, OH Sinha, SK Rafailovich, M Sokolov, J Shin, K Tolan, M TI Surface properties of soft matter thin films studied by X-ray and neutron scattering methods. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Argonne Natl Lab, APS XFD, Argonne, IL 60439 USA. SUNY Stony Brook, Stony Brook, NY USA. Univ Kiel, D-24098 Kiel, Germany. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 168-COLL BP U448 EP U448 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901361 ER PT J AU Selinskaya, YA Akhmetov, MD Khotimsky, VS Volkov, VV Fadeev, AG Meagher, MM Kelley, SS AF Selinskaya, YA Akhmetov, MD Khotimsky, VS Volkov, VV Fadeev, AG Meagher, MM Kelley, SS TI Study on pervaporation and sorption of 1-butanol aqueous solutions and fermentation mixtures using poly(1-trimethylsilyl-1-propyne) membranes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 AV Topchiev Petrochem Synth Inst, Moscow 117912, Russia. AV Topchiev Petrochem Synth Inst, Lincoln, NE 68583 USA. Univ Nebraska, Biol Proc Dev Facil, Lincoln, NE 68583 USA. Ctr Renewable Chem Technol & Mat, Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 14-MACR BP U710 EP U710 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034002148 ER PT J AU Seliskar, CJ Slaterbeck, A Shi, YN Maizels, M Ross, S Stegemiller, M Ridgway, TH Heineman, WR Bryan, SA AF Seliskar, CJ Slaterbeck, A Shi, YN Maizels, M Ross, S Stegemiller, M Ridgway, TH Heineman, WR Bryan, SA TI Novel spectroelectrochemical sensor for ferrocyanide in Hanford waste simulant. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Cincinnati, Dept Chem, Cincinnati, OH 45221 USA. Pacific NW Lab, Radiochem Proc Lab, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 142-NUCL BP U1070 EP U1070 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903207 ER PT J AU Semenov, VV Zelinsky, ND Gakh, AA AF Semenov, VV Zelinsky, ND Gakh, AA TI Symbiotic chemistry of aliphatic and heterocyclic nitrocompounds. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 ND Zelinskii Organ Chem Inst, Moscow 117913, Russia. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 29-ORGN BP U16 EP U16 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034000030 ER PT J AU Sepaniak, M Gibson, T Jeremy, H Christopher, T Panos, D AF Sepaniak, M Gibson, T Jeremy, H Christopher, T Panos, D TI Strategies to immobilize chemically selective reagent phases to enhance microsensor performance. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 143-NUCL BP U1070 EP U1070 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903208 ER PT J AU Shults, WD AF Shults, WD TI Beauty of analytical chemistry. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 102-ANYL BP U157 EP U157 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033900418 ER PT J AU Smith, BB Nozik, AJ AF Smith, BB Nozik, AJ TI Theoretical studies of the semiconductor-liquid interface. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 23-COLL BP U406 EP U406 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901217 ER PT J AU Smith, DM Neu, MP Garcia, E Dole, VR AF Smith, DM Neu, MP Garcia, E Dole, VR TI Plutonium pyrochemical salts oxidation and distillation processing: Residue stabilization and fundamental studies. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Nucl Mat & Technol Div, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 594-INOR BP U891 EP U892 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033902703 ER PT J AU Sowder, AG Clark, SB Fjeld, RA AF Sowder, AG Clark, SB Fjeld, RA TI Impact of mineralogy in the U(VI)-Ca-PO4 system on the environmental availability of uranium: Consequences for radioactive waste management. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Washington State Univ, Dept Chem, Pullman, WA 99164 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Clemson Univ, Dept Environm Engn & Sci, Clemson, SC 29634 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 104-NUCL BP U1058 EP U1058 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903169 ER PT J AU Spath, P Amos, W Chambers, H Madden, DR Smith, D Shelton, W AF Spath, P Amos, W Chambers, H Madden, DR Smith, D Shelton, W TI Technoeconomic analysis of hydrogen production from western coal augmented with CO2 sequestration and coalbed methane recovery. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. EG&G, TSWV, Wellesley, MA 02181 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 94-FUEL BP U631 EP U631 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901908 ER PT J AU Stanka, B Hebenstreit, W Reed, W Diebold, U Chambers, SA AF Stanka, B Hebenstreit, W Reed, W Diebold, U Chambers, SA TI Treatment-dependent surface reconstruction of FE3O4(001). SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. Pacific NW Lab, Richland, WA 99352 USA. RI Diebold, Ulrike/A-3681-2010 OI Diebold, Ulrike/0000-0003-0319-5256 NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 74-COLL BP U420 EP U420 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901268 ER PT J AU Stevens, B Wilson, EL AF Stevens, B Wilson, EL TI Thermal Decomposition of Cellulose. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 13-TECH BP U379 EP U379 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901130 ER PT J AU Stewart, FF Harrup, MK Peterson, ES Stone, ML Orme, CJ Polson, LA AF Stewart, FF Harrup, MK Peterson, ES Stone, ML Orme, CJ Polson, LA TI Chemically tailored phosphazene polymers for water separations applications: Synthesis, characterization, and membrane formation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Lockheed Martin Idaho Technol Co, Idaho Natl Engn Lab, Idaho Falls, ID 83415 USA. RI Peterson, Eric/B-9127-2017 OI Peterson, Eric/0000-0002-2292-4939 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 19-MACR BP U711 EP U711 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034002153 ER PT J AU Stiegel, GJ Maxwell, RC AF Stiegel, GJ Maxwell, RC TI Changing markets and needs refocus and expand the Federal Energy Technology Center's gasification-based technologies program. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US DOE, Fed Energy Technol Ctr, Pittsburgh, PA 15236 USA. Burns & Roe Serv Corp, Pittsburgh, PA 15236 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 37-FUEL BP U613 EP U614 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901853 ER PT J AU Stoyer, MA Hudson, GB Lougheed, RW Sangster, TC AF Stoyer, MA Hudson, GB Lougheed, RW Sangster, TC TI Omega gas-sampling system and radiochemical diagnostics for NIF. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Analyt & Nucl Chem Div, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 141-NUCL BP U1069 EP U1069 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903206 ER PT J AU Struve, WS Savikhin, S Chitnis, PR Xu, W AF Struve, WS Savikhin, S Chitnis, PR Xu, W TI Electronic excitation transport and trapping in wild-pipe and mutant photosystem 1 from synechocystis SPPCC 6803. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Dept Biochem & Biophys, Ames, IA 50011 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 36-PHYS BP U285 EP U285 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034000772 ER PT J AU Swanson, B AF Swanson, B TI Integrated optical biosensor: An ultrasensitive and specific biosensor inspired by nature. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Ctr Biomimet Sensors & Mat, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 311-INOR BP U802 EP U802 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033902429 ER PT J AU Sylwester, AP AF Sylwester, AP TI Sandia's microchemlab program. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Sandia Natl Labs, Catalysis & Chem Technol Dept, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 134-ANYL BP U166 EP U166 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033900446 ER PT J AU Tanner, DD Vigneswaran, M Kandanarchchi, P Das, NC Franz, JA AF Tanner, DD Vigneswaran, M Kandanarchchi, P Das, NC Franz, JA TI Solution-phase chemistry of atomic hydrogen: Reactions with organic substrates. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 53-FUEL BP U619 EP U619 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901869 ER PT J AU Terminello, LJ AF Terminello, LJ TI Actinide Sciences Summer School Program at LLNL. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Inst Transactinium Sci, Analyt & Nucl Chem Div, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 139-NUCL BP U1068 EP U1069 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903204 ER PT J AU Trauth, KM Gruebel, MM AF Trauth, KM Gruebel, MM TI Environmental protection agency regulatory framework as a contributing factor for certification of the waste isolation pilot plant. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 28-NUCL BP U1035 EP U1035 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903093 ER PT J AU Tumas, W AF Tumas, W TI Catalysis in dense-phase fluids for environmentally benign chemical synthesis. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Los Alamos Catalyis Initiat, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 298-INOR BP U799 EP U799 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033902420 ER PT J AU Van den Avyle, JA Molecke, MA Williamson, RL Melgaard, DK Pal, UB Chernicoff, WP MacDonald, CJ Bychkov, SI Podoynitsin, S Kudinov, KG AF Van den Avyle, JA Molecke, MA Williamson, RL Melgaard, DK Pal, UB Chernicoff, WP MacDonald, CJ Bychkov, SI Podoynitsin, S Kudinov, KG TI Electroslag remelting process studies for decontamination of stainless steels: Current results. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Min & Chem Combine, Sci Technol Ctr, Zheleznogorsk, Russia. Boston Univ, Boston, MA 02215 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 68-NUCL BP U1047 EP U1047 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903133 ER PT J AU Vance, AL Baumann, TF Fox, GA AF Vance, AL Baumann, TF Fox, GA TI Hydroxy-salen complexes as sol-gel precursors. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Lawrence Livermore Natl Lab, Div Chem & Chem Engn, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 109-INOR BP U744 EP U744 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033902245 ER PT J AU Vanheusden, K Devine, RAB Fleetwood, DM Warren, WL AF Vanheusden, K Devine, RAB Fleetwood, DM Warren, WL TI Nonvolatile memory application using mobile protons in the gate oxide. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USAF, Res Lab, VSSE, Kirtland AFB, NM 87117 USA. France Telecom, Ctr Natl Etud Telecommun, F-38243 Meylan, France. Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 18-COMP BP U484 EP U484 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901465 ER PT J AU Volkov, VV Gokzhaev, MM Malakhov, AO Samokhvalov, RV Kelley, SS AF Volkov, VV Gokzhaev, MM Malakhov, AO Samokhvalov, RV Kelley, SS TI Microheterogeneity and free volume structure of poly(1-trimethylsilyl-1-propyne). SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 AV Topchiev Petrochem Synth Inst, Moscow 117912, Russia. NREL, Golden, CO 80401 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 7-MACR BP U708 EP U708 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034002141 ER PT J AU Waezsada, SD Dai, S Barnes, CE Xue, ZL AF Waezsada, SD Dai, S Barnes, CE Xue, ZL TI Combined ionic exchange and ligand modification approaches to highly-selective mesoporous silica. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 82-NUCL BP U1052 EP U1052 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903147 ER PT J AU Walters, EA Grover, JR Arnberg, DL Hagenow, G Clay, CTT Cheng, BM Willcox, MVV AF Walters, EA Grover, JR Arnberg, DL Hagenow, G Clay, CTT Cheng, BM Willcox, MVV TI Kinetic energy release distributions in the photoionization-induced dissociative rearrangements of weak complexes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Free Univ Berlin, Inst Phys Chem, D-1000 Berlin, Germany. Synchrotron Radiat Res Ctr, Hsinchu, Taiwan. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 208-PHYS BP U333 EP U333 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034000933 ER PT J AU Wang, HB Yu, LP Wang, HH AF Wang, HB Yu, LP Wang, HH TI Self-assembly study of a series of novel amphiphilic rod-coil diblock copolymers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 426-POLY BP U520 EP U520 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034001567 ER PT J AU Wang, ZM Li, H Li, LY Joly, AG Strachan, DM Qian, MX Davis, LL Darab, JG AF Wang, ZM Li, H Li, LY Joly, AG Strachan, DM Qian, MX Davis, LL Darab, JG TI Fluorescence spectroscopic study of gadolinium in sodium-alumino-borosilicate glass. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Pacific NW Lab, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 166-NUCL BP U1077 EP U1077 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903231 ER PT J AU Ward, TE AF Ward, TE TI Possible role of pep weak interactions in the early history of the earth. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US DOE, Washington, DC 20585 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 119-NUCL BP U1063 EP U1063 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903184 ER PT J AU Watkin, JG Hijar, CA Scott, BL AF Watkin, JG Hijar, CA Scott, BL TI Neutral and anionic transition-metal complexes supported by decafluorodiphenylamido ligands. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 511-INOR BP U866 EP U866 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033902622 ER PT J AU Watkin, JG Carter, CAG Bercaw, JE Labinger, JA Whitwell, GE AF Watkin, JG Carter, CAG Bercaw, JE Labinger, JA Whitwell, GE TI Homogeneous alkane functionalization catalysis. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. CALTECH, Pasadena, CA 91125 USA. Akzo Nobel Chem, Cent Res, Dobbs Ferry, NY 10522 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 7-IEC BP U678 EP U678 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033902041 ER PT J AU Weiss, S Dahan, M Lacoste, T Glass, J Laurence, T Chemla, DS Deniz, A Ting, A Grunwell, J Faulhaber, AE Schultz, PG AF Weiss, S Dahan, M Lacoste, T Glass, J Laurence, T Chemla, DS Deniz, A Ting, A Grunwell, J Faulhaber, AE Schultz, PG TI Observing single biomolecule reactions. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RI Dahan, Maxime /F-1740-2010 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 80-PHYS BP U297 EP U297 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034000812 ER PT J AU White, MG Rao, RM Beuhler, RJ AF White, MG Rao, RM Beuhler, RJ TI Development of a 2-D imaging detector for surface photochemistry applications. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 197-PHYS BP U330 EP U330 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034000922 ER PT J AU Whitten, DG Chen, L Wang, HL Geiger, HC Place, I McBranch, D Penner, TL AF Whitten, DG Chen, L Wang, HL Geiger, HC Place, I McBranch, D Penner, TL TI Supramolecular assemblies based on surfactant polymer interactions. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 15-COLL BP U404 EP U404 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901209 ER PT J AU Wilkerson, CW Hemberger, PH Cisper, ME Allen, TM AF Wilkerson, CW Hemberger, PH Cisper, ME Allen, TM TI Real-time broad spectrum characterization of hazardous waste by membrane introduction mass spectrometry. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 146-NUCL BP U1071 EP U1071 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903211 ER PT J AU Winans, RE Hunt, JE AF Winans, RE Hunt, JE TI Overview of resid characterization by mass spectrometry and small-angle scattering techniques. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 60-FUEL BP U620 EP U621 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901876 ER PT J AU Winans, RE Seifert, S Thiyagarajan, P AF Winans, RE Seifert, S Thiyagarajan, P TI Time-resolved small-angle X-ray scattering reactivity studies on coals, asphaltenes, and polymers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 8-FUEL BP U605 EP U605 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901824 ER PT J AU Wolf, SF Lipschutz, ME AF Wolf, SF Lipschutz, ME TI Heterogeneous accretion of the H chondrite parent body. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 116-NUCL BP U1062 EP U1062 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033903181 ER PT J AU Wouters, ER Ahmed, M Peterka, DS Vasyutinskii, OS Suits, AG AF Wouters, ER Ahmed, M Peterka, DS Vasyutinskii, OS Suits, AG TI Atomic orbital angular momentum alignment and coherence in the photodissociation of nitrous oxide and ozone. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Ernest Orlando Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. Russian Acad Sci, Ioffe Physicotech Inst, St Petersburg 194021, Russia. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 398-PHYS BP U386 EP U386 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034001115 ER PT J AU Wunderlich, B AF Wunderlich, B TI Analysis of the nanophase structure of semicrystalline polymers with atomic force microscopy (AFM), microcalorimetry (MC), and temperature-modulated calorimetry (TMC). SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Knoxville, TN 37996 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 122-PMSE BP U637 EP U637 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034001918 ER PT J AU Xantheas, SS AF Xantheas, SS TI Critical issues in the understanding and modeling of collective effects in water. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RI Xantheas, Sotiris/L-1239-2015 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 62-PHYS BP U292 EP U292 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034000795 ER PT J AU Xu, LQ Carrado, KA AF Xu, LQ Carrado, KA TI In situ hydrothermal synthesis of surface-functionalized hectorite from gels containing organosilanes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 149-COLL BP U442 EP U442 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901342 ER PT J AU Xu, LQ Carrado, KA AF Xu, LQ Carrado, KA TI Synthesis of polymer-clay materials as catalyst precursors using a microwave-heating technique. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 106-INOR BP U743 EP U743 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033902241 ER PT J AU Xu, YW Tait, CD Runde, WH AF Xu, YW Tait, CD Runde, WH TI Formation and stability of uranyl(VI) hydroxo-halido complexes in aqueous systems. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 110-ENVR BP U576 EP U576 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033901749 ER PT J AU Yeung, ES Pang, HM Xue, G Gong, XY AF Yeung, ES Pang, HM Xue, G Gong, XY TI Highly multiplexed capillary electrophoresis: Going beyond DNA analysis. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 135-ANYL BP U166 EP U166 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033900447 ER PT J AU Yeung, ES Xu, XN Shortreed, MR AF Yeung, ES Xu, XN Shortreed, MR TI Combining spectroscopy and chromatography in analytical chemistry. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 118-ANYL BP U161 EP U161 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033900430 ER PT J AU Yoder, LM Barker, JR Lorenz, KT Chandler, DW AF Yoder, LM Barker, JR Lorenz, KT Chandler, DW TI Recoil energy disposal in the vibrational predissociation of some van der Waals dimers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Michigan, Ann Arbor, MI 48109 USA. Sandia Natl Labs, Livermore, CA 94550 USA. RI Barker, John/F-5904-2012 OI Barker, John/0000-0001-9248-2470 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 98-PHYS BP U302 EP U302 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034000828 ER PT J AU Zerkle, DK Paffett, MT AF Zerkle, DK Paffett, MT TI Elucidating the role of homogeneous reactions in methane-conversion chemistry in a short-contact-time reactor. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Calif Los Alamos Natl Lab, CST Div, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 6-IEC BP U677 EP U677 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226QZ UT WOS:000082033902040 ER PT J AU Zlotin, SG Serebryakov, EA Kislitsin, PG Konyushkin, LD Semenov, VV Buchanan, AC Gakh, AA AF Zlotin, SG Serebryakov, EA Kislitsin, PG Konyushkin, LD Semenov, VV Buchanan, AC Gakh, AA TI Nitro-1,2-benzoisothiazoles and isothiazolones from polynitroaromatic compounds and related chemistry. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 ND Zelinskii Organ Chem Inst, Moscow 117913, Russia. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 22 PY 1999 VL 218 MA 48-ORGN BP U22 EP U22 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 226RA UT WOS:000082034000049 ER PT J AU Pomes, R Eisenmesser, E Post, CB Roux, B AF Pomes, R Eisenmesser, E Post, CB Roux, B TI Calculating excess chemical potentials using dynamic simulations in the fourth dimension SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FREE-ENERGY CALCULATIONS; MOLECULAR-DYNAMICS; LAMBDA-DYNAMICS; COMPUTER-SIMULATIONS; BINDING AFFINITIES; LIQUID WATER; THERMODYNAMICS; HYDRATION; SOLUTES; SYSTEM AB A general method for computing excess chemical potentials is presented. The excess chemical potential of a solute or ligand molecule is estimated from the potential of mean-force (PMF) calculated along a nonphysical fourth spatial dimension, w, into which the molecule is gradually inserted or from which it is gradually abstracted. According to this "4D-PMF" (four dimensional) scheme, the free energy difference between two limiting states defines the excess chemical potential: At w = +/-infinity, the molecule is not interacting with the rest of the system, whereas at w=0, it is fully interacting. Use of a fourth dimension avoids the numerical instability in the equations of motion encountered upon growing or shrinking solute atoms in conventional free energy perturbation simulations performed in three dimensions, while benefiting from the efficient sampling of configurational space afforded by PMF calculations. The applicability and usefulness of the method are illustrated with calculations of the hydration free energy of simple Lennard-Jones (LJ) solutes, a water molecule, and camphor, using molecular dynamics simulations and umbrella sampling. Physical insight into the nature of the PMF profiles is gained from a continuum treatment of short- and long-range interactions. The short-range barrier for dissolution of a LJ solute in the added dimension provides an apparent surface tension of the solute. An approximation to the long-range behavior of the PMF profiles is made in terms of a continuum treatment of LJ dispersion and electrostatic interactions. Such an analysis saves the need for configurational sampling in the long-range limit of the fourth dimension. The 4D-PMF method of calculating excess chemical potentials should be useful for neutral solute and ligand molecules with a wide range of sizes, shapes, and polarities. (C) 1999 American Institute of Physics. [S0021-9606(99)51231-2]. C1 Los Alamos Natl Lab, Theoret Biol & Biophys Grp T10, Los Alamos, NM 87545 USA. Purdue Univ, Dept Med Chem, W Lafayette, IN 47901 USA. Univ Montreal, Dept Phys, Montreal, PQ H3C 3J7, Canada. Univ Montreal, Dept Chim, Montreal, PQ H3C 3J7, Canada. RP Los Alamos Natl Lab, Theoret Biol & Biophys Grp T10, Mail Stop K710, Los Alamos, NM 87545 USA. EM regis@lanl.gov; rouxb@plgcn.umontreal.ca NR 31 TC 24 Z9 24 U1 1 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 22 PY 1999 VL 111 IS 8 BP 3387 EP 3395 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 224ZF UT WOS:000081929300008 ER PT J AU Cao, YW Chai, XD Li, TJ Smith, J Li, DQ AF Cao, YW Chai, XD Li, TJ Smith, J Li, DQ TI Self-patterned H-bond supramolecular self-assembly SO CHEMICAL COMMUNICATIONS LA English DT Article ID SOLID-STATE; MOLECULAR RECOGNITION; MONOLAYERS; WATER; SUPERLATTICE; SURFACES; TAPES AB Barbituric acid and melamine derivatives self-assembled into highly ordered structures from the molecular scale (similar to 3 Angstrom) to geometric patterns on a macroscale (similar to 0.5 mm). C1 Jilin Univ, Dept Chem, Changchun 10023, Peoples R China. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div CST4, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RP Li, DQ (reprint author), Jilin Univ, Dept Chem, Changchun 10023, Peoples R China. NR 20 TC 16 Z9 17 U1 1 U2 1 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD AUG 21 PY 1999 IS 16 BP 1605 EP 1606 DI 10.1039/a902674f PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 222BT UT WOS:000081764000078 ER PT J AU Sablik, MJ Jiles, DC AF Sablik, MJ Jiles, DC TI A modified Stoner-Wohlfarth computational model for hysteretic magnetic properties in a ferromagnetic composite rod under torsion SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID TORQUE; STRESS; RING AB In this paper, a Stoner-Wohlfarth approach to magnetic hysteresis is used as a model for a fenomagnetic composite rod consisting of single domain 'grains' with random orientations embedded in a non-magnetic matrix. The rod is considered to be under torsional stress, which means that the rod at each point on its outer surface is experiencing biaxial stress along axes at 45 degrees relative to the rod axis, with one stress equal to sigma and the other equal to -sigma. A magnetic field is considered to act parallel to the rod axis. The modified Stoner-Wohlfarth model of Callegaro and Puppin is adapted to this biaxial stress configuration. Results computed using the adapted model are presented and compared to results computed previously that were obtained by applying the domain wall pinning model to the torsional stress situation. It was found that the adapted model results are not very sensitive to the maximum value of the field, while the opposite is true for results from the domain wall pinning model. Secondly, the coercivity increased with torque, instead of the opposite situation with the domain wall pinning model, where coercivity decreased with torque. Reasons for this behaviour are presented in the paper. Differences related to symmetry properties of the model are also discussed. Finally, the model exhibits the possibility of both first- and second-order transitions in the hysteresis curve for different values of torque. C1 SW Res Inst, San Antonio, TX 78228 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Sablik, MJ (reprint author), SW Res Inst, PO Drawer 28510, San Antonio, TX 78228 USA. RI Jiles, David/H-9548-2012 NR 23 TC 7 Z9 7 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD AUG 21 PY 1999 VL 32 IS 16 BP 1971 EP 1983 DI 10.1088/0022-3727/32/16/304 PG 13 WC Physics, Applied SC Physics GA 231DA UT WOS:000082291800007 ER PT J AU Va'vra, J AF Va'vra, J CA CRID Collaboration TI Long-term operational experience with the barrel CRID at SLD SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Workshop on Ring Imaging Cherenkov Detectors (RICH98) CY NOV 15-20, 1998 CL EN GEDI, ISRAEL SP Israel Sci Fdn, Weizmann Inst Sci ID RING-IMAGING DETECTOR; PHOTOCATHODE; SYSTEMS AB The Barrel GRID detector has been operating successfully at SLD for the past seven years. It is an important tool for SLD physics analyses. The long-term operational experience with this device is described. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Va'vra, J (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, SLAC Bin 62,POB 4349, Stanford, CA 94309 USA. NR 38 TC 18 Z9 18 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 1999 VL 433 IS 1-2 BP 59 EP 70 DI 10.1016/S0168-9002(99)00367-8 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 229MW UT WOS:000082199200007 ER PT J AU Adam, I Aleksan, R Aston, D Bailly, P Beigbeder, C Benayoun, M Benkebil, M Bonneaud, G Breton, D Briand, H Brown, D Bourgeois, P Chauveau, J Cizeron, R Cohen-Tanugi, J Convery, M Dardin, S David, P De Domenico, G de la Vaissiere, C de Lesquen, A Del Buono, L Doser, M Emery, S Fouque, G Gaidot, A Gastaldi, F Genat, JF Geld, T Gosset, L Hale, D de Monchenault, GH Hamon, O Hoecker, A Imbault, D Kadel, RW Kadyk, J Kalelkar, M Karolak, M Kawahara, H Krueger, H Le Diberder, F Lebbolo, H Leruste, PH London, G Long, M Lory, J Lu, A Lutz, AM Lynch, G Mancinelli, G McCulloch, M McShurley, D Malchow, R Matricon, P Mayer, B Meadows, B Micout, P Muller, D Narjoux, JL Noppe, JM Oshatz, D Oxoby, G Plano, R Plaszczynski, S Pripstein, M Rasson, J Ratcliff, B Reif, R Renard, C Roos, L Roussot, E Salnikov, A Sarazin, X Schune, MH Schwiening, J Sen, S Shelkov, V Sokoloff, M Staengle, H Spanier, S Stiles, P Stone, R Thiebaux, C Truong, K Toki, W Valassi, A Vasileiadis, G Vasseur, G Va'vra, J Verderi, M Versille, S Warner, D Weber, T Weber, TF Wenzel, W Wilson, R Wormser, G Yeche, C Yellin, S Zhang, B Zito, M AF Adam, I Aleksan, R Aston, D Bailly, P Beigbeder, C Benayoun, M Benkebil, M Bonneaud, G Breton, D Briand, H Brown, D Bourgeois, P Chauveau, J Cizeron, R Cohen-Tanugi, J Convery, M Dardin, S David, P De Domenico, G de la Vaissiere, C de Lesquen, A Del Buono, L Doser, M Emery, S Fouque, G Gaidot, A Gastaldi, F Genat, JF Geld, T Gosset, L Hale, D de Monchenault, GH Hamon, O Hoecker, A Imbault, D Kadel, RW Kadyk, J Kalelkar, M Karolak, M Kawahara, H Krueger, H Le Diberder, F Lebbolo, H Leruste, PH London, G Long, M Lory, J Lu, A Lutz, AM Lynch, G Mancinelli, G McCulloch, M McShurley, D Malchow, R Matricon, P Mayer, B Meadows, B Micout, P Muller, D Narjoux, JL Noppe, JM Oshatz, D Oxoby, G Plano, R Plaszczynski, S Pripstein, M Rasson, J Ratcliff, B Reif, R Renard, C Roos, L Roussot, E Salnikov, A Sarazin, X Schune, MH Schwiening, J Sen, S Shelkov, V Sokoloff, M Staengle, H Spanier, S Stiles, P Stone, R Thiebaux, C Truong, K Toki, W Valassi, A Vasileiadis, G Vasseur, G Va'vra, J Verderi, M Versille, S Warner, D Weber, T Weber, TF Wenzel, W Wilson, R Wormser, G Yeche, C Yellin, S Zhang, B Zito, M TI The DIRC detector at BaBar SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Workshop on Ring Imaging Cherenkov Detectors (RICH98) CY NOV 15-20, 1998 CL EN GEDI, ISRAEL SP Israel Sci Fdn, Weizmann Inst Sci ID CHERENKOV AB A dedicated particle identification system based on the Detection of Internally Reflected Cherenkov (DIRC) light will be used in the BaBar detector. We provide an overview of the DIRC concept, design, and expected performance of the production device and a status report on its construction and commissioning. The DIRC is expected to be operating in the BaBar detector on beam line at the PEP-II B Factory in late spring 1999. 1999 Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. CEA, DAPNIA, CE Saclay, F-91191 Gif Sur Yvette, France. Univ Paris 06, LPNHE, F-75252 Paris 05, France. Univ Paris 07, LPNHE, F-75252 Paris 05, France. Univ Paris Sud, LAL Orsay, F-91405 Orsay, France. Ecole Polytech, LPNHE, F-91128 Palaiseau, France. Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Rutgers State Univ, Dept Phys, Piscataway, NJ 08855 USA. Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. RP Pripstein, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Valassi, Andrea/K-7506-2012; OI Valassi, Andrea/0000-0001-9322-9565; Wilson, Robert/0000-0002-8184-4103 NR 7 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 1999 VL 433 IS 1-2 BP 121 EP 127 DI 10.1016/S0168-9002(99)00352-6 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 229MW UT WOS:000082199200014 ER PT J AU Korpar, S Arinyo, I Atiya, M Broemmelsiek, D Carvalho, J Dujmic, D Eckmann, R Garrido, L Gorisek, A Ivaniouchenkov, I Ispirian, M Karabekian, S Krizan, P Lau, K Maas, P McGill, J Miquel, R Pestotnik, R Pyrlik, J Ramachadran, D Reeves, K Rosen, J Schwitters, R Staric, M Stanovnik, A Skrk, D AF Korpar, S Arinyo, I Atiya, M Broemmelsiek, D Carvalho, J Dujmic, D Eckmann, R Garrido, L Gorisek, A Ivaniouchenkov, I Ispirian, M Karabekian, S Krizan, P Lau, K Maas, P McGill, J Miquel, R Pestotnik, R Pyrlik, J Ramachadran, D Reeves, K Rosen, J Schwitters, R Staric, M Stanovnik, A Skrk, D TI The HERA-B RICH SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Workshop on Ring Imaging Cherenkov Detectors (RICH98) CY NOV 15-20, 1998 CL EN GEDI, ISRAEL SP Israel Sci Fdn, Weizmann Inst Sci ID DETECTOR AB The essential components of the ring imaging Cherenkov detector for the HERA-B experiment are briefly described. Results of the first test measurements with the HERA proton beam are presented and the capability of the RICH to identify kaons is estimated. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Jozef Stefan Inst, Ljubljana, Slovenia. Univ Ljubljana, Ljubljana, Slovenia. Univ Barcelona, Barcelona, Spain. BNL, Upton, NY USA. Northwestern Univ, Evanston, IL USA. LIP, Coimbra, Portugal. Univ Texas, Austin, TX 78712 USA. DESY, D-2000 Hamburg, Germany. Univ Houston, Houston, TX USA. RP Korpar, S (reprint author), Jozef Stefan Inst, Ljubljana, Slovenia. RI Carvalho, Joao/M-4060-2013; OI Carvalho, Joao/0000-0002-3015-7821; Garrido Beltran, Lluis/0000-0001-8883-6539; Krizan, Peter/0000-0002-4967-7675; Miquel, Ramon/0000-0002-6610-4836 NR 8 TC 18 Z9 18 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 1999 VL 433 IS 1-2 BP 128 EP 135 DI 10.1016/S0168-9002(99)00324-1 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 229MW UT WOS:000082199200015 ER PT J AU Akiba, Y Begay, R Burward-Hoy, J Chappell, R Crook, D Ebisu, K Emery, MS Ferriera, J Frawley, AD Hamagaki, H Hara, H Hayano, RS Hemmick, TK Hibino, M Hutter, R Kennedy, M Kikuchi, J Matsumoto, T Moscone, CG Nagasaka, Y Nishimura, S Oyama, K Sakaguchi, T Salomone, S Shigaki, K Tanaka, Y Walker, JW Wintenberg, AL Young, GR AF Akiba, Y Begay, R Burward-Hoy, J Chappell, R Crook, D Ebisu, K Emery, MS Ferriera, J Frawley, AD Hamagaki, H Hara, H Hayano, RS Hemmick, TK Hibino, M Hutter, R Kennedy, M Kikuchi, J Matsumoto, T Moscone, CG Nagasaka, Y Nishimura, S Oyama, K Sakaguchi, T Salomone, S Shigaki, K Tanaka, Y Walker, JW Wintenberg, AL Young, GR TI Ring imaging Cherenkov detector of PHENIX experiment at RHIC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Workshop on Ring Imaging Cherenkov Detectors (RICH98) CY NOV 15-20, 1998 CL EN GEDI, ISRAEL SP Israel Sci Fdn, Weizmann Inst Sci AB The RICH detector of the PHENIX experiment at RHIC is currently under construction. Its main function is to identity electron tracks in a very high particle density, about 1000 charged particles per unit rapidity, expected in the most violent collisions at RHIC. The design and construction status of the detector and its expected performance are described. (C) 1999 Elsevier Science B.V. All rights reserved. C1 High Energy Accelerator Res Org, Tsukuba, Ibaraki 3050801, Japan. SUNY Stony Brook, Stony Brook, NY 11794 USA. Florida State Univ, Tallahassee, FL 32306 USA. Nagasaki Inst Appl Sci, Nagasaki 8510193, Japan. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tokyo, Ctr Nucl Study, Tokyo 1880002, Japan. Univ Tokyo, Tokyo 1130033, Japan. Waseda Univ, Tokyo 1698555, Japan. RP Akiba, Y (reprint author), High Energy Accelerator Res Org, Tsukuba, Ibaraki 3050801, Japan. RI Hayano, Ryugo/F-7889-2012; HAMAGAKI, HIDEKI/G-4899-2014 OI Hayano, Ryugo/0000-0002-1214-7806; NR 3 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 1999 VL 433 IS 1-2 BP 143 EP 148 DI 10.1016/S0168-9002(99)00319-8 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 229MW UT WOS:000082199200017 ER PT J AU Engelfried, J Filimonov, I Kilmer, J Kozhevnikov, A Kubarovsky, V Molchanov, V Nemitkin, A Ramberg, E Rud, V Stutte, L AF Engelfried, J Filimonov, I Kilmer, J Kozhevnikov, A Kubarovsky, V Molchanov, V Nemitkin, A Ramberg, E Rud, V Stutte, L TI The RICH detector of the SELEX experiment SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Workshop on Ring Imaging Cherenkov Detectors (RICH98) CY NOV 15-20, 1998 CL EN GEDI, ISRAEL SP Israel Sci Fdn, Weizmann Inst Sci DE RICH detector; phototubes AB A RICH detector was used during the 1996/7 fixed target run at Fermilab in experiment E781 - SELEX. The detector utilizes a matrix of 2848 phototubes for the photocathode. The figure of merit, N-o, has been measured to be in excess of 100 cm(-1). The ring radius resolution for multitrack events has been measured to be 1.8 mm, which gives K/pi. separation on a 2 sigma level up to a momentum of 165 GeV/c, and p/pi separation up to 320 GeV/c. We will describe the design of the detector, discuss the stability during operation, and report on achieved results (C) 1999 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL USA. Moscow State Univ, Moscow, Russia. Inst High Energy Phys, Protvino, Russia. RP Engelfried, J (reprint author), Univ Autonoma San Luis Potosi, Manuel Nava 6,Zona Univ, San Luis Potosi 78240, Mexico. NR 9 TC 12 Z9 12 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 1999 VL 433 IS 1-2 BP 149 EP 152 DI 10.1016/S0168-9002(99)00308-3 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 229MW UT WOS:000082199200018 ER PT J AU Muller, D AF Muller, D CA SLD Collaboration TI Physics results from SLD using the GRID SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Workshop on Ring Imaging Cherenkov Detectors (RICH98) CY NOV 15-20, 1998 CL EN GEDI, ISRAEL SP Israel Sci Fdn, Weizmann Inst Sci DE GRID; RICH; SLD ID Z(0); BOSONS; QUARKS AB We review recent Z(0) physics results from SLD that use CRID particle identification. The performance of the detector and likelihood method are described briefly. Several hadronization measurements are presented, including identified hadron production in events of different primary flavors; leading hadron production, and new correlation studies sensitive to details of both leading and nonleading hadron production. Identified K+/- have been used in conjunction with precision vertexing to study charmless and doubly charmed B-hadron decays. This combination has also been used to tag b, (b) over bar, c and (c) over bar jets, yielding precise measurements of B-0-(B) over bar(0) mixing and of the asymmetric couplings A(b) and A(c). Identified K+/- and Lambda(0)/<(Lambda)over bar>(0) have been used to tag s and (s) over bar jets, yielding a measurement of A(s). The clean identified particle samples provided efficiently by the CRID allow the purities of these tags to be measured from the data, an essential ingredient for precision physics. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94305 USA. RP Muller, D (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, POB 4349,Bin 68, Stanford, CA 94305 USA. NR 16 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 1999 VL 433 IS 1-2 BP 314 EP 327 DI 10.1016/S0168-9002(99)00339-3 PG 14 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 229MW UT WOS:000082199200044 ER PT J AU Krizan, P Arinyo, I Atiya, M Broemmelsiek, D Carvalho, J Dujmic, D Eckmann, R Garrido, L Gorisek, A Ispirian, M Ivaniouchenkov, I Karabekyan, S Korpar, S Lau, K Miquel, R Pestotnik, R Pyrlik, J Ramachadran, D Reeves, K Rosen, J Schwitters, R Skrk, D Stanovnik, A Staric, M Zivko, T AF Krizan, P Arinyo, I Atiya, M Broemmelsiek, D Carvalho, J Dujmic, D Eckmann, R Garrido, L Gorisek, A Ispirian, M Ivaniouchenkov, I Karabekyan, S Korpar, S Lau, K Miquel, R Pestotnik, R Pyrlik, J Ramachadran, D Reeves, K Rosen, J Schwitters, R Skrk, D Stanovnik, A Staric, M Zivko, T TI The physics potential of the HERA-B RICH SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Workshop on Ring Imaging Cherenkov Detectors (RICH98) CY NOV 15-20, 1998 CL EN GEDI, ISRAEL SP Israel Sci Fdn, Weizmann Inst Sci DE RICH; HERA-B experiment; high-energy physics ID DETECTOR AB The physics potential of the RICH counter of the HERA-B experiment is illustrated in several MC simulated examples. In particular, we discuss its performance as an auxiliary tracking device. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Ljubljana, Jozef Stefan Inst, Ljubljana 61000, Slovenia. Univ Barcelona, Barcelona, Spain. BNL, Upton, NY USA. Northwestern Univ, Evanston, IL USA. Univ Coimbra, LIP, Coimbra, Portugal. Univ Texas, Austin, TX 78712 USA. DESY, D-2000 Hamburg, Germany. Univ Houston, Houston, TX USA. RP Krizan, P (reprint author), Univ Ljubljana, Jozef Stefan Inst, POB 100,Jadranska 19, Ljubljana 61000, Slovenia. RI Carvalho, Joao/M-4060-2013; OI Carvalho, Joao/0000-0002-3015-7821; Garrido Beltran, Lluis/0000-0001-8883-6539; Krizan, Peter/0000-0002-4967-7675; Miquel, Ramon/0000-0002-6610-4836 NR 5 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 1999 VL 433 IS 1-2 BP 357 EP 365 DI 10.1016/S0168-9002(99)00328-9 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 229MW UT WOS:000082199200050 ER PT J AU Bailly, P Chauveau, J Del Buono, L Genat, JF Lebbolo, H Roos, L Zhang, B Beigbeder, C Bernier, R Breton, D Caceres, T Chase, R Ducorps, A Hrisoho, A Imbert, P Sen, S Tocut, V Truong, K Wormser, G Zomer, F Bonneaud, G Dohou, F Gastaldi, F Matricon, P Renard, C Thiebaux, C Vasileiadis, G Verderi, M Oxoby, G Va'Vra, J Warner, D Wilson, RJ AF Bailly, P Chauveau, J Del Buono, L Genat, JF Lebbolo, H Roos, L Zhang, B Beigbeder, C Bernier, R Breton, D Caceres, T Chase, R Ducorps, A Hrisoho, A Imbert, P Sen, S Tocut, V Truong, K Wormser, G Zomer, F Bonneaud, G Dohou, F Gastaldi, F Matricon, P Renard, C Thiebaux, C Vasileiadis, G Verderi, M Oxoby, G Va'Vra, J Warner, D Wilson, RJ TI The DIRC front-end electronics chain for BaBar SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Workshop on Ring Imaging Cherenkov Detectors (RICH98) CY NOV 15-20, 1998 CL EN GEDI, ISRAEL SP Israel Sci Fdn, Weizmann Inst Sci DE BaBar detector; DIRC; DCC; high-energy particles AB The detector of Internally Reflected Cherenkov light (DIRC) of the BaBar detector (SLAC Stanford, USA) measures better than 1 ns the arrival time of Cherenkov photoelectrons, detected in a 11 000 phototubes array and their amplitude spectra. It mainly comprises of 64-channel DIRC Front-End Boards (DFB) equipped with eight full-custom Analog chips performing zero-cross discrimination with 2 mV threshold and pulse shaping, four full-custom Digital TDC chips for timing measurements with 500 ps binning and a readout logic selecting hits in the trigger window, and DIRC Crate Controller cards (DCC) serializing the data collected from up to 16 DFBs onto a 1.2 Gb/s optical link. Extensive test of the pre-production chips have been performed as well as system tests. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Paris 06, Lab Phys Nucl & Hautes Energies, F-75252 Paris, France. Univ Paris 07, CNRS, IN2P3, F-75252 Paris, France. Univ Paris Sud, Accelerateur Lineaire Lab, CNRS, IN2P3, F-91405 Orsay, France. Ecole Polytech, Lab Phys Nucl & Hautes Energies, CNRS, IN2P3, F-91128 Palaiseau, France. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Colorado State Univ, Ft Collins, CO 80523 USA. RP Genat, JF (reprint author), Univ Paris 06, Lab Phys Nucl & Hautes Energies, T33 RC,4 Pl Jussieu, F-75252 Paris, France. NR 8 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 1999 VL 433 IS 1-2 BP 450 EP 455 DI 10.1016/S0168-9002(99)00461-1 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 229MW UT WOS:000082199200064 ER PT J AU Ratcliff, BN Spanier, S AF Ratcliff, BN Spanier, S TI DIRC dreams: research directions for the next generation of internally reflected imaging counters SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Workshop on Ring Imaging Cherenkov Detectors (RICH98) CY NOV 15-20, 1998 CL EN GEDI, ISRAEL SP Israel Sci Fdn, Weizmann Inst Sci ID PARTICLE IDENTIFICATION; CHERENKOV; PROTOTYPE; DEVICE; LIGHT AB Some conceptual design features of the total internally reflecting, imaging Cherenkov counter (DIRC) are described. Limits of the DIRC approach to particle identification, and a few features of alternative DIRC designs, are briefly explored. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Ratcliff, BN (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 15 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 1999 VL 433 IS 1-2 BP 456 EP 463 DI 10.1016/S0168-9002(99)00355-1 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 229MW UT WOS:000082199200065 ER PT J AU Va'vra, J Manzin, G McCulloch, M Stiles, P Sauli, F AF Va'vra, J Manzin, G McCulloch, M Stiles, P Sauli, F TI Fast drift GRID with GEM SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 3rd International Workshop on Ring Imaging Cherenkov Detectors (RICH98) CY NOV 15-20, 1998 CL EN GEDI, ISRAEL SP Israel Sci Fdn, Weizmann Inst Sci ID ELECTRON MULTIPLIER GEM; PHOTON DETECTORS; AMPLIFICATION AB The only available technique at the present time, to perform particle identification up to 40-50 GeV/c in a 4 pi solenoidal geometry using the Cherenkov ring imaging method is the use of gaseous detectors filled with either TMAE or TEA photocathodes, and a combination of the gaseous, and solid or liquid radiators. If one would consider building such a device, one may want to investigate alternative methods of building a single-electron detector. This paper investigates the feasibility of using the GEM together with a simple MWPC detector employing 33 mu m diameter carbon wires to obtain a second coordinate. The results are compared to the GRID single-electron detector. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. CERN, Geneva, Switzerland. RP Va'vra, J (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, SLAC Bin62,POB 4349, Stanford, CA 94309 USA. NR 13 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 21 PY 1999 VL 433 IS 1-2 BP 527 EP 532 DI 10.1016/S0168-9002(99)00368-X PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 229MW UT WOS:000082199200077 ER PT J AU Alcock, C Allsman, RA Alves, D Axelrod, TS Becker, AC Bennett, DP Cook, KH Drake, AJ Freeman, KC Griest, K Lehner, MJ Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Stubbs, CW Sutherland, W Tomaney, A Vandehei, T Welch, DL AF Alcock, C Allsman, RA Alves, D Axelrod, TS Becker, AC Bennett, DP Cook, KH Drake, AJ Freeman, KC Griest, K Lehner, MJ Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Stubbs, CW Sutherland, W Tomaney, A Vandehei, T Welch, DL CA MACHO Collaboration TI Difference image analysis of galactic microlensing. I. Data analysis SO ASTROPHYSICAL JOURNAL LA English DT Article DE atmospheric effects; Galaxy : stellar content; gravitational lensing; techniques : image processing ID COMPACT HALO OBJECTS; UNRESOLVED STARS; MACHO PROJECT; BULGE; EVENTS; SEARCH; REFRACTION; M-31 AB This is a preliminary report on the application of Difference Image Analysis (DIA) to Galactic bulge images. The aim of this analysis is to increase the sensitivity to the detection of gravitational microlensing. We discuss how the DIA technique simplifies the process of discovering microlensing events by detecting only objects that have variable flux. We illustrate how the DIA technique is not limited to detection of so-called "pixel lensing" events but can also be used to improve photometry for classical microlensing events by removing the effects of blending. We will present a method whereby DIA can be used to reveal the true unblended colors, positions, and light curves of microlensing events. We discuss the need for a technique to obtain the accurate microlensing timescales from blended sources and present a possible solution to this problem using the existing Hubble Space Telescope color-magnitude diagrams of the Galactic bulge and LMC. The use of such a solution with both classical and pixel microlensing searches is discussed. We show that one of the major causes of systematic noise in DIA is differential refraction. A technique for removing this systematic by effectively registering images to a common air mass is presented. Improvements to commonly used image differencing techniques are discussed. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Australian Natl Univ, Supercomp Facil, Canberra, ACT 0200, Australia. Univ Calif Berkeley, Dept Phys, Berkeley, CA 95616 USA. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Weston, ACT 2611, Australia. Univ Washington, Dept Phys & Astron, Seattle, WA 98195 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. Univ Sheffield, Dept Phys, Sheffield S3 7RH, S Yorkshire, England. Pontificia Univ Catolica Chile, Dept Astron, Santiago 22, Chile. MIT, Ctr Space Res, Cambridge, MA 02139 USA. European So Observ, D-85748 Garching, Germany. Univ Oxford, Dept Phys, Oxford OX1 3RH, England. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. RP Alcock, C (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Stubbs, Christopher/C-2829-2012; Quinn, Peter/B-3638-2013; OI Stubbs, Christopher/0000-0003-0347-1724; Lehner, Matthew/0000-0003-4077-0985 NR 34 TC 49 Z9 49 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 1999 VL 521 IS 2 BP 602 EP 612 DI 10.1086/307567 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 226JX UT WOS:000082017800016 ER PT J AU Hoffman, RD Woosley, SE Weaver, TA Rauscher, T Thielemann, FK AF Hoffman, RD Woosley, SE Weaver, TA Rauscher, T Thielemann, FK TI The reaction rate sensitivity of nucleosynthesis in type II supernovae SO ASTROPHYSICAL JOURNAL LA English DT Article DE nuclear reactions, nucleosynthesis, abundances stars : interiors; supernovae : general ID THERMONUCLEAR REACTION-RATES; GIANT-DIPOLE RESONANCE; WEAK-INTERACTION RATES; INTERMEDIATE-MASS NUCLEI; CAPTURE CROSS-SECTIONS; S-PROCESS; RADIATION WIDTHS; NEUTRON-CAPTURE; LESS-THAN; P-PROCESS AB We explore the sensitivity of the nucleosynthesis of intermediate-mass elements (28 less than or equal to A less than or similar to 80) in supernovae derived from massive stars to the nuclear reaction rates employed in the model. Two standard sources of reaction rate data are employed in pairs of calculations that are otherwise identical. Both include as a common backbone the experimental reactions rates of Caughlan & Fowler. Two stellar models are calculated for each of two masses: 15 and 25 M.. Each star is evolved from core hydrogen burning to a presupernova state carrying an appropriately large reaction network and then exploded using a piston near the edge of the iron core as described by Woosley & Weaver. The final stellar yields from the models calculated with the two rate sets are compared and found to differ in most cases by less than a factor of 2 over the entire range of nuclei studied. Reasons for the major discrepancies along with the physics underlying the two reaction rate sets employed are discussed in detail. The nucleosynthesis results are relatively robust and less sensitive than might be expected to uncertainties in nuclear reaction rates, though they are sensitive to the stellar model employed. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Max Planck Inst Astrophys, D-85740 Garching, Germany. Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland. Univ Calif Santa Barbara, Inst Theoret Phys, Santa Barbara, CA 93106 USA. RP Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RI Rauscher, Thomas/D-2086-2009 OI Rauscher, Thomas/0000-0002-1266-0642 NR 97 TC 63 Z9 63 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 1999 VL 521 IS 2 BP 735 EP 752 DI 10.1086/307568 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 226JX UT WOS:000082017800029 ER PT J AU Drake, JJ Swartz, DA Beiersdorfer, P Brown, GV Kahn, SM AF Drake, JJ Swartz, DA Beiersdorfer, P Brown, GV Kahn, SM TI On photospheric fluorescence and the nature of the 17.62 angstrom feature in solar X-ray spectra SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic processes; line : formation; line : identification; Sun : corona; Sun : X-rays, gamma rays ID PHOTOIONIZATION CROSS-SECTIONS; ABUNDANCE; FLARE; IRON; SPECTROMETER; SUN AB The identification of the emission-line feature at 17.62 Angstrom, in solar X-ray spectra is reexamined. Using a Monte Carlo technique, we compute a realistic theoretical upper limit to the observed Fe L alpha photospheric fluorescent line strength caused by irradiation from an overlying corona. These calculations demonstrate that the photospheric Fe L alpha characteristic line is much too weak to account for the observed 17.62 Angstrom, line flux. Instead, we identify this line with the configuration interaction 2s(2)2p(4)3p P-2(3/2)-2s2p(6) S-2(1/2) transition in Fe XVIII seen in Electron Beam Ion Trap spectra and predicted in earlier theoretical work on the Fe XVIII X-ray spectrum. This line should be easily resolved and detected in stellar coronae by the spectrographs on the upcoming Chandra X-ray Observatory, and X-ray Multi-mirror Mission. C1 Harvard Smithsonian Ctr Astrophys, Chandra Xray Ctr, Cambridge, MA 02138 USA. NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Columbia Univ, Dept Phys, New York, NY 10027 USA. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. RP Harvard Smithsonian Ctr Astrophys, Chandra Xray Ctr, MS-3,60 Garden St, Cambridge, MA 02138 USA. EM jdrake@cfa.harvard.edu; swartz@avalon.msfc.nasa.gov; beiersdorfer@llnl.gov; brown86@llnl.gov; skahn@astro.columbia.edu NR 28 TC 19 Z9 21 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 1999 VL 521 IS 2 BP 839 EP 843 DI 10.1086/307593 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 226JX UT WOS:000082017800035 ER PT J AU Frieman, JA Gaztanaga, E AF Frieman, JA Gaztanaga, E TI The projected three-point correlation function: Theory and observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; cosmology : theory; large-scale structure of universe; methods : analytical; methods : numerical ID 3-POINT CORRELATION-FUNCTION; LARGE-SCALE STRUCTURE; APM GALAXY SURVEY; GAUSSIAN INITIAL CONDITIONS; HIGHER-ORDER STATISTICS; SHANE-WIRTANEN CATALOG; QUASI-LINEAR REGIME; POWER SPECTRUM; COSMOLOGICAL PERTURBATIONS; GRAVITATIONAL-INSTABILITY AB We report results for the angular three-point galaxy correlation function in the APM Galaxy Survey and compare them with theoretical expectations. For the first time, these measurements extend to sufficiently large scales to probe the weakly nonlinear regime. On large scales, the results are in good agreement with the predictions of nonlinear cosmological perturbation theory for a model with initially Gaussian fluctuations and linear power spectrum P(k) consistent with that inferred from the APM survey. These results reinforce the conclusion that large-scale structure is driven by nonlinear gravitational instability and that APM galaxies are relatively unbiased tracers of the mass on large scales; they also provide stringent constraints upon models with non-Gaussian initial conditions and strongly exclude the standard cold dark matter model. C1 NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. CSIC, Inst Estudis Espacials Catalunya, IEEC, Barcelona 08034, Spain. RP Frieman, JA (reprint author), NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 38 TC 56 Z9 58 U1 1 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 1999 VL 521 IS 2 BP L83 EP L86 DI 10.1086/312195 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 226KA UT WOS:000082018100002 ER PT J AU Herman, GS Peden, CHF AF Herman, GS Peden, CHF TI Segregation of K at the TiO2(100) surface SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article; Proceedings Paper CT 2nd Conference on Surface Characterization of Adsorption and Interfacial Reactions CY JAN 11-16, 1998 CL KEANHOU KONA, HAWAII SP Engn Fdn, Natl Sci Fdn, Int Assoc Colloid & Interface Scientists, US/Japan Ctr UT DE TiO2; potassium; AES ID ENERGY ELECTRON-DIFFRACTION; ION-SCATTERING SPECTROSCOPY; CATALYTIC PROPERTIES; POTASSIUM; OXYGEN; V2O5/TIO2; TITANIUM AB We have studied the segregation of potassium to the surface of TiO2(100) using Auger electron spectroscopy (AES), low energy electron diffraction (LEED), direct recoil spectroscopy (DRS), and mass-spectroscopy of recoiled ions (MSRI). It is found that the concentration of potassium at the surface is strongly influenced by the sample temperature. MSRI results indicate the presence of potassium starting at annealing temperatures of 675 K and the subsequent disappearance above 875 K. Conversely, AES only indicates the presence of potassium after annealing the sample to 975 K. Together these results indicate that below 875 K, potassium exists in the very topmost surface layer, while above 875 K, potassium is located below this layer. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Herman, GS (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999,MS K8-93, Richland, WA 99352 USA. OI Peden, Charles/0000-0001-6754-9928 NR 18 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD AUG 20 PY 1999 VL 154 IS 1-2 BP 187 EP 192 DI 10.1016/S0927-7757(98)00896-6 PG 6 WC Chemistry, Physical SC Chemistry GA 213LK UT WOS:000081274200019 ER PT J AU Waller, KL Cooke, BM Nunomura, W Mohandas, N Coppel, RL AF Waller, KL Cooke, BM Nunomura, W Mohandas, N Coppel, RL TI Mapping the binding domains involved in the interaction between the Plasmodium falciparum knob-associated histidine-rich protein (KAHRP) and the cytoadherence ligand P-falciparum erythrocyte membrane protein 1 (PfEMP1) SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID RED-CELL MEMBRANE; INFECTED ERYTHROCYTES; SURFACE-ANTIGEN; OPTICAL BIOSENSOR; MALARIAL ANTIGEN; RESONANT MIRROR; GENE; SPECTRIN; SEQUENCE; THROMBOSPONDIN AB Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) clusters at electron-dense knob-like structures on the surface of malaria-infected red blood cells and mediates their adhesion to the vascular endothelium. In parasites lacking knobs, vascular adhesion is less efficient, and infected red cells are not able 60 immobilize successfully under hemodynamic flow conditions even though PfEMP1 is still present on the exterior of the infected red cell. me examined the interaction between the knob-associated histidine-rich protein (KAHRP), the parasite protein upon which knob formation is dependent, and PfEMP1, and we show evidence of a direct interaction between KAHRP and the cytoplasmic region of PfEMP1 (VARC). We have identified three fragments of KAHRP which bind VARC. Two of these KAHRP fragments (K1A and K2A) interact with VARC with binding affinities (K-D(kin)) of 1 x 10(-7) M and 3.3 x 10(-6) M respectively, values comparable to those reported previously for protein-protein interactions in normal and infected red cells. Further experiments localized the high affinity binding regions of KAHRP to the 63-residue histidine-rich and 70-residue 5' repeats. Deletion of these two regions from the KAHRP fragments abolished their ability to bind to VARC. Identification of the critical domains involved in interaction between KAHRP and PfEMP1 may aid development of new therapies to prevent serious complications of P. falciparum malaria. C1 Monash Univ, Dept Microbiol, Clayton, Vic 3168, Australia. Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Coppel, RL (reprint author), Monash Univ, Dept Microbiol, Clayton, Vic 3168, Australia. RI Coppel, Ross/A-6626-2008 OI Coppel, Ross/0000-0002-4476-9124 FU NIDDK NIH HHS [DK-32094] NR 41 TC 104 Z9 106 U1 0 U2 5 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD AUG 20 PY 1999 VL 274 IS 34 BP 23808 EP 23813 DI 10.1074/jbc.274.34.23808 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 227ZV UT WOS:000082110900021 PM 10446142 ER PT J AU Roberts, KP Lin, CH Jankowiak, R Small, GJ AF Roberts, KP Lin, CH Jankowiak, R Small, GJ TI On-line identification of diastereomeric dibenzo[a,l]pyrene diol epoxide-derived deoxyadenosine adducts by capillary electrophoresis-fluorescence line-narrowing and non-line narrowing spectroscopy SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 12th International Symposium on High Performance Capillary Electrophoresis and Related Microscale Techniques CY JAN 23-28, 1999 CL PALM SPRINGS, CALIFORNIA DE detection, electrophoresis; fluorescence detection; fluoresence lime narrowing spectroscopy; fluoresence non-line narrowing spectroscopy; deoxyadenosine; dibenzopyrene diol epoxide; DNA; polynuclear aromatic hydrocarbons ID POLYCYCLIC AROMATIC-HYDROCARBONS; CHROMATOGRAPHY MASS-SPECTROMETRY; SHELLFISH POISONING TOXINS; MOUSE SKIN; ELECTROKINETIC CHROMATOGRAPHY; LIQUID-CHROMATOGRAPHY; DNA-ADDUCTS; 7,12-DIMETHYLBENZANTHRACENE; BENZOPYRENE; CARCINOGENESIS AB A capillary electrophoretic method for the separation and on-line identification of closely related analytes using low-temperature fluorescence spectroscopy is reported for the eight diastereomeric deoxyadenosine (dA) adducts derived from dibenzo[a,l]pyrene diol epoxide (DB[a,l]PDE). Electrophoretic separation of stereoisomers was accomplished by application of a mixed surfactant buffer [dioctyl sulfosuccinate (DOSS)and Brij-S], which was below the critical micelle concentration (CMC) due to the high concentration (similar to 25%) of organic solvent. Addition of multiple surfactant additives to the separation buffer provided electrophoretic resolution, which was unattainable under single surfactant conditions. It is shown that the CE-separated analyte zones could be identified on-line via low-temperature (4.2 K) fluorescence non-line narrowing and fluorescence line-narrowing (FLN) spectroscopy. In addition, it was determined that in CE buffer trans-syn-,cis-syn- and cis-anti-DB[a,l]PDE-14-N(6)dA diastereomeric adducts exist mostly with the -dA and DB[a,l]P moiety in an "open"-type conformation while the trans-anti-DB[a,l]PDE-14-N6dA adducts exist in two different conformations whose relative distribution depends on matrix composition. The above conformations have also been revealed by selective laser excitation. Thus, the low-temperature methodology not only provides fingerprint structure via vibrationally resolved 4.2 K fluorescence spectra for adduct identification, but also provides conformational information on the spatial relationship of the carcinogen and dA moiety. These results, taken together with those for DB[a,I]P-DNA adducts formed in standard glasses and mouse epidermis exposed to DB[a,l]P, support our earlier findings that DB[a,l]P-derived adducts exist in different conformations [Jankowiak et al., Chem. Res. Toxicol. 11 (1998) 674]. Therefore, the combination of the separation power of CE and spectral selectivity of low-temperature fluorescence spectroscopy at NLN and FLN conditions provides a powerful methodology which should prove useful for identification of closely related DNA adducts formed at low levels in biological systems. (C) 1999 Elsevier Science BN. All rights reserved. C1 US Dept Energy, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. RP Jankowiak, R (reprint author), US Dept Energy, Ames Lab, Ames, IA 50011 USA. FU NCI NIH HHS [P0I CA49210-0] NR 47 TC 16 Z9 17 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD AUG 20 PY 1999 VL 853 IS 1-2 BP 159 EP 170 DI 10.1016/S0021-9673(99)00507-5 PG 12 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 229VX UT WOS:000082217400018 PM 10486722 ER PT J AU Lu, SX Yeung, ES AF Lu, SX Yeung, ES TI Side-entry excitation and detection of square capillary array electrophoresis for DNA sequencing SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 12th International Symposium on High Performance Capillary Electrophoresis and Related Microscale Techniques CY JAN 23-28, 1999 CL PALM SPRINGS, CALIFORNIA DE detection; electrophoresis; instrumentation; DNA ID ASSISTED LASER-DESORPTION; IONIZATION MASS-SPECTROMETRY; CROSS-LINKED POLYACRYLAMIDE; HIGH-SPEED; POLY(ETHYLENE OXIDE); FRAGMENTS; SEPARATIONS; OLIGONUCLEOTIDES; HYBRIDIZATION; MOLECULE AB In high throughput DNA sequencing based on capillary electrophoresis, efficient coupling of the laser to each capillary is a challenge. Our group previously reported two multiple point irradiation schemes. The present work describes a more efficient excitation and detection method in which the laser light propagates through the capillary array without undergoing a serious reduction in power. An array of square capillaries (340 mu m O.D.x75 mu m LD.) was sandwiched between two fused-silica plates with an index-matching solution in between. The light was directed into the channel across the capillary array from the side. DNA sequences of PGEM/U from 24 capillaries were obtained even with a relatively low-power laser. The excitation scheme can be scaled up to hundreds of capillaries to achieve high-speed, high-throughput DNA sequencing, genetic typing and drug screening. (C) 1999 Elsevier Science B.V. All rights reserved. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Yeung, ES (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. NR 49 TC 19 Z9 20 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD AUG 20 PY 1999 VL 853 IS 1-2 BP 359 EP 369 DI 10.1016/S0021-9673(99)00676-7 PG 11 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 229VX UT WOS:000082217400039 PM 10486743 ER PT J AU Huang, RL Espenson, JH AF Huang, RL Espenson, JH TI Kinetics and mechanism of the methyltrioxorhenium-catalyzed sulfoxidation of thioketones and sulfines SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID METHYLRHENIUM TRIOXIDE; HYDROGEN-PEROXIDE; OXYGEN-TRANSFER; OXIDATION; OXIDES; EPOXIDATION; DERIVATIVES AB Kinetic studies have been carried out on the oxidation of thiobenzophenones and thiocamphor by hydrogen peroxide and on the second step in the sequence, oxidation of the resulting sulfines (Ar2C=S=O). The first reaction follows the pattern now common to methyltrioxorhenium/H2O2 reactions, in that the rate constant for the reaction between the peroxorhenium intermediate and the thioketone follows a Hammett; correlation such that electron-releasing substrates react more rapidly. The reaction constant is rho = -1.12. However, the plot of log(k(X)/k(H)) for the sulfines against 2 sigma, determined over the range -1.6 < 2 sigma < +1.5, is markedly U-shaped. This suggests a mechanism for the sulfines in which the direction of the electron flow in the transition state changes with the electron demand of the substituents on the sulfines. The product of oxidation of the sulfine is a transient sultine (from epoxidation of the C=S bond). It cannot be detected, however, because it so rapidly yields sulfur monoxide. The SO was oxidized to SO2 under these conditions rather than undergoing disproportionation to SO2 and S. Also, SO was trapped with a 1,3-diene as a thiophene-1-oxide. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. RP Espenson, JH (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 52 TC 23 Z9 24 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD AUG 20 PY 1999 VL 64 IS 17 BP 6374 EP 6379 DI 10.1021/jo990621e PG 6 WC Chemistry, Organic SC Chemistry GA 230GN UT WOS:000082243600034 ER PT J AU Giannetta, RW Tea, NH Chaves, FAB Rao, S Salamon, MB Kini, AM Wang, HH Geiser, U Schlueter, J Trawick, MW Garland, JC AF Giannetta, RW Tea, NH Chaves, FAB Rao, S Salamon, MB Kini, AM Wang, HH Geiser, U Schlueter, J Trawick, MW Garland, JC TI Lockin transition, irreversibility field, and Josephson vortex penetration depth in kappa-(ET)(2)Cu[N(CN)(2)]Br SO PHYSICA C LA English DT Article DE kappa-(ET)(2)Cu[N(CN)(2)]Br; lockin effect; Josephson vortices; irreversibility line; penetration depth; lower critical field ID HIGH-TEMPERATURE SUPERCONDUCTORS; PRESSURE ORGANIC SUPERCONDUCTOR; LAYERED SUPERCONDUCTORS; IN TRANSITION; BEHAVIOR; VORTICES; CUBR; RELAXATION; BARRIERS; LINE AB Penetration depth measurements in K-(ET)(2)Cu[N(CN)(2)]Br are reported for fields H up to 1 T in magnitude and arbitrary orientation. For H nearly parallel to the conducting planes, the vortex penetration depth is nonmonotonic with field, indicating a lockin effect. Qualitatively similar behavior is observed in BSCCO. The data indicate a much stronger interaction between vortex kinks than predicted. In the field range over which vortex kinks are first formed, the response is hysteretic with an irreversibility field equal to the lower critical field. Both fields show positive curvature with temperature, suggesting relaxation over surface barriers. Josephson vortices exhibit single vortex pinning below 300 Oe. Between 300 and 1500 Oe, the Josephson vortex penetration depth changes dramatically, becoming proportional to both H and to the zero field interplane penetration depth, lambda(perpendicular to)(T)- lambda(perpendicular to)(0). (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Illinois, Sci & Technol Ctr Superconduct, Urbana, IL 61801 USA. Argonne Natl Lab, Div Chem & Mat Sci, Argonne, IL 60439 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. RP Giannetta, RW (reprint author), Univ Illinois, Dept Phys, 1110 W Green St, Urbana, IL 61801 USA. RI Kini, Aravinda/F-4467-2012 NR 30 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD AUG 20 PY 1999 VL 321 IS 3-4 BP 207 EP 218 DI 10.1016/S0921-4534(99)00382-2 PG 12 WC Physics, Applied SC Physics GA 243NP UT WOS:000083004400009 ER PT J AU Turner, JA AF Turner, JA TI Biomass in the energy picture - Response SO SCIENCE LA English DT Letter C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Turner, JA (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 1 TC 1 Z9 1 U1 0 U2 3 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 20 PY 1999 VL 285 IS 5431 BP 1209 EP 1210 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 228HC UT WOS:000082130200015 ER PT J AU Vaidya, RU Jin, Z Cady, C Gray, GT Butt, DP AF Vaidya, RU Jin, Z Cady, C Gray, GT Butt, DP TI A comparative study of the strain rate and temperature dependent compression behavior of Ti-46.5Al-3Nb-2Cr-0.2W and Ti-25Al-10Nb-3V-1Mo intermetallic alloys SO SCRIPTA MATERIALIA LA English DT Article DE intermetallics; mechanical properties; strain rate ID DEFORMATION C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Reynolds Met Co, Corp Tech Ctr, Chester, VA 23836 USA. Ceramtec Inc, Salt Lake City, UT 84119 USA. RP Vaidya, RU (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 15 TC 12 Z9 14 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD AUG 20 PY 1999 VL 41 IS 6 BP 569 EP 574 DI 10.1016/S1359-6462(99)00195-5 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 230TE UT WOS:000082265800001 ER PT J AU Keblinski, P Wolf, D Phillpot, SR Gleiter, H AF Keblinski, P Wolf, D Phillpot, SR Gleiter, H TI Structure of grain boundaries in nanocrystalline palladium by molecular dynamics simulation SO SCRIPTA MATERIALIA LA English DT Article DE computer simulation; grain boundaries; diffusion-interface; metals ID X-RAY-DIFFRACTION; PD C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Forschungszentrum Karlsruhe, D-76021 Karlsruhe, Germany. RP Keblinski, P (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Phillpot, Simon/J-9117-2012; OI Phillpot, Simon/0000-0002-7774-6535 NR 16 TC 84 Z9 88 U1 2 U2 30 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD AUG 20 PY 1999 VL 41 IS 6 BP 631 EP 636 DI 10.1016/S1359-6462(99)00142-6 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 230TE UT WOS:000082265800010 ER PT J AU Roberts, JG Hoffer, S Van Hove, MA Somorjai, GA AF Roberts, JG Hoffer, S Van Hove, MA Somorjai, GA TI Tensor low-energy electron diffraction analysis of the surface structure of NaCl(100) thin films grown on Pd(100) and Pt(111) SO SURFACE SCIENCE LA English DT Article DE alkali halides; electron-solid diffraction; evaporation and sublimation; growth; insulating films; low energy electron diffraction (LEED); low index single crystal surfaces; surface relaxation and reconstruction ID LEED; CRYSTALLOGRAPHY; MONOLAYER AB Thin films of NaCl were molecularly deposited and subsequently ordered on Pd(100) and Pt(111), These films exhibited the same adsorbate-substrate interaction on Pd(100) and Pt(111) as evidenced by the lone multilayer desorption peak observed in the temperature programmed desorption spectra of NaCl on these two substrates. The ordered structures of the films were produced by exposing a heated substrate to a flux of NaCl emanating from a Knudsen cell and investigated through the use of low-energy electron diffraction (LEED). On Pd(100), the adsorbed multilayer yielded a (1 x 1) NaCl(100) LEED pattern. The (1 x 1) pattern was seen as the result of the film's thickness being greater than the sampling depth of the elastically scattered electrons used in the LEED experiment, thus removing the contribution of the substrate's lattice to the observed pattern. For the (1 x 1) pattern of NaCl(100) on Pd(100), it was found that the NaCl film grew along the [010]-type surface directions of Pd(100) to take advantage of a near 1:1 lattice match. On Pt(111), the ordered NaCl multilayer gave a (1 x 1) NaCl(100) LEED pattern also, but, unlike Pd(100), one of the overlayer's unit cell vectors lies parallel to that of the substrate's with the other rotated by 90 degrees from the previous one to preserve the geometry of the NaCl(100) lattice. Multiple intensity versus electron energy (IV) data sets were gathered for the NaCl(100) multilayer film on both Pd(100) and Pt(111), An analysis of the I-V curves of the multilayer NaCl(100) pattern on both substrates showed that the multilayer has the same structure on both substrates to a depth sampled by the electrons in the experimental energy range. Data from both systems were used in a fully dynamical LEED calculation. In the final structure, which refined down to a Pendry R-factor (R-P) of 0.16, the largest deviation from the ideally terminated NaCl(100) structure was the movement of the surface Na+ towards the bulk, thereby causing a 0.12+/-0.03 Angstrom corrugation of the surface layer. This shift of the surface cations was not followed by a corresponding displacement of the underlying anions, so the first interlayer spacing, d(Cl-2-Na-1), was reduced to 2.72+/-0.03 Angstrom from its bulk value of 2.82 Angstrom. Deviations from the bulk were smaller in subsequent layers, e.g, the second interlayer spacing, d(Na-3-Cl-2), was 2.77 +/- 0.03 Angstrom, and there was essentially no buckling of the second layer. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Van Hove, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 22 TC 22 Z9 22 U1 1 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 20 PY 1999 VL 437 IS 1-2 BP 75 EP 85 DI 10.1016/S0039-6028(99)00686-X PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 231UH UT WOS:000082328800012 ER PT J AU Li, M Hebenstreit, W Gross, L Diebold, U Henderson, MA Jennison, DR Schultz, PA Sears, MP AF Li, M Hebenstreit, W Gross, L Diebold, U Henderson, MA Jennison, DR Schultz, PA Sears, MP TI Oxygen-induced restructuring of the TiO2(110) surface: a comprehensive study SO SURFACE SCIENCE LA English DT Article DE oxygen; restructuring; TiO2; scanning tunneling microscopy; low energy ion scattering; oxidation; secondary ion mass spectroscopy; density functional calculations ID SCANNING-TUNNELING-MICROSCOPY; SINGLE-CRYSTAL RUTILE; ELECTRONIC-STRUCTURE; THERMAL-STABILITY; INTRINSIC DEFECTS; ADSORPTION; DIFFUSION; FILMS; OXIDE; WATER AB We report a comprehensive experimental and theoretical study of the effect of oxidizing a TiO2(110) surface at moderate temperatures. The surfaces are investigated with scanning tunneling microscopy (STM), low-energy He+ ion scattering (LEIS) and static secondary ion mass spectroscopy (SSIMS). Flat(1 x 1)-terminated TiO2(110) surfaces are obtained by sputtering and annealing in UHV at 880 K. These surfaces are exposed to oxygen gas at elevated temperatures in the range 470-830 K. Formation of irregular networks of pseudo-hexagonal rosettes (6.5 Angstrom x 6 Angstrom) and small (1 (1) over bar 0] oriented (1 x 1) islands along with {001}-oriented strands is induced at temperatures from 470 to 660 K. After annealing above 830 K, only regular (1 x 1) terraces and white strands are observed. The composition of these oxygen-induced phases is quantified using O-18(2) gas in combination with LEIS and SSIMS measurements. The dependence of the restructuring process on annealing time, annealing temperature, and sample history is systematically investigated. Exposure to (H2O)-O-18 and air in the same temperature regime fails to induce the restructuring. UHV annealing of restructured, oxygen-enriched TiO2(110) surface smooths the surfaces and converts the rosette networks into strands and finally into the regular (1 x 1) terraces. This is reported in an accompanying paper [M. Li, W. Hebenstreit, U. Diebold, Phys. Rev. B (1999), submitted]. The rosette model is supported by first-principles density functional calculations which show a stable structure results, accompanied by significant relaxations from bulk-truncated positions. A mechanism for the dynamic processes of the formation of rosettes and (1 x 1) islands is presented and the importance of these results for the surface chemistry of TiO2(110) surfaces is discussed. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. Pacific NW Lab, Richland, WA 99352 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. EM diebold@mailhost.tcs.tulane.edu RI Gross, Leo/E-1789-2011; Diebold, Ulrike/A-3681-2010 OI Gross, Leo/0000-0002-5337-4159; Diebold, Ulrike/0000-0003-0319-5256 NR 71 TC 154 Z9 154 U1 7 U2 60 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 EI 1879-2758 J9 SURF SCI JI Surf. Sci. PD AUG 20 PY 1999 VL 437 IS 1-2 BP 173 EP 190 DI 10.1016/S0039-6028(99)00720-7 PG 18 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 231UH UT WOS:000082328800023 ER PT J AU Herman, GS AF Herman, GS TI Characterization of surface defects on epitaxial CeO2(001) films SO SURFACE SCIENCE LA English DT Article DE ceria; cerium oxide; mass spectroscopy of recoiled ions; surface defects ID CERIA FILMS; OXYGEN; ADSORPTION; CATALYSTS; CEO2(111); HYDROGEN; OXIDE; CO AB The thermal generation of defects on epitaxial CeO2(001) films was studied with mass spectroscopy of recoiled ions (MSRI) and direct recoil spectroscopy (DRS). It was found that cerium and oxygen intensities changed significantly after annealing the surface to temperatures as low as 373 K. Subsequent dosing at 295 K with O-18(2), resulted in an increase in the oxygen MSRI signal, however, the total preanneal signal was not fully recovered. For anneal temperatures above 473 K, and with a subsequent 10 Langmuir (L) O-18(2), dose at 295 K, the O-18 isotopic ratio was found to be between 20 and 23%, These results suggest that a significant number of defect sites were created on the surface even at low temperatures. After annealing the sample to 775 K the concentration of defects at the surface was estimated to be similar to 11-12% by MSRI and DRS. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Herman, GS (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. NR 22 TC 33 Z9 34 U1 4 U2 20 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 20 PY 1999 VL 437 IS 1-2 BP 207 EP 214 DI 10.1016/S0039-6028(99)00723-2 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 231UH UT WOS:000082328800026 ER PT J AU Bogicevic, A Jennison, DR AF Bogicevic, A Jennison, DR TI Role of surface vacancies and water products in metal nucleation: Pt/MgO(100) SO SURFACE SCIENCE LA English DT Letter DE density-functional theory; first-principles; metal nucleation; oxides; surface vacancies; water ID MOLECULAR-DYNAMICS; ATOMS; TRANSITION; ADSORPTION; EXCHANGE; AL(111); DEFECTS; SOLIDS AB Density-functional calculations reveal that isolated F-s and V-s surface vacancies on MgO(100) ionize single Pt atoms, roughly tripling their adsorption energy. This trapping inhibits Pt atoms from binding to other Pt atoms, resulting in a negative addimer binding energy. Hence, isolated surface vacancies demote nucleation, contrary to popular belief. A defect that does promote nucleation is the FsVs divacancy, which increases the addimer binding energy by 20%. Amongst water and its dissociation products, only adsorbed hydroxyls are found to have a similar (but stronger) effect. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Surface & Interface Sci Dept, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, Surface & Interface Sci Dept, POB 5800, Albuquerque, NM 87185 USA. EM abogice@sandia.gov NR 24 TC 86 Z9 86 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 EI 1879-2758 J9 SURF SCI JI Surf. Sci. PD AUG 20 PY 1999 VL 437 IS 1-2 BP L741 EP L747 DI 10.1016/S0039-6028(99)00746-3 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 231UH UT WOS:000082328800001 ER PT J AU Muzzi, CM Medforth, CJ Voss, L Cancilla, M Lebrilla, C Ma, JG Shelnutt, JA Smith, KM AF Muzzi, CM Medforth, CJ Voss, L Cancilla, M Lebrilla, C Ma, JG Shelnutt, JA Smith, KM TI Novel dodecaarylporphyrins: synthesis and dynamic properties SO TETRAHEDRON LETTERS LA English DT Article ID CROSS-COUPLING REACTIONS; SUBSTITUTED PORPHYRINS; NONPLANAR PORPHYRINS; DEPENDENCE AB An investigation of the synthesis of dodecaarylporphyrins using the Suzuki coupling reaction of arylboronic acids with octabromotetraarylporphyrins is reported. Variable temperature H-1 NMR studies of these new porphyrins reveal several dynamic processes including the first examples of beta-aryl rotation. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. Sandia Natl Labs, New Mat Theory & Validat Dept, Albuquerque, NM 87185 USA. RP Medforth, CJ (reprint author), Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. RI Shelnutt, John/A-9987-2009; Medforth, Craig/D-8210-2013; REQUIMTE, FMN/M-5611-2013; REQUIMTE, UCIBIO/N-9846-2013; Smith, Kevin/G-1453-2011 OI Shelnutt, John/0000-0001-7368-582X; Medforth, Craig/0000-0003-3046-4909; Smith, Kevin/0000-0002-6736-4779 NR 16 TC 24 Z9 24 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0040-4039 J9 TETRAHEDRON LETT JI Tetrahedron Lett. PD AUG 20 PY 1999 VL 40 IS 34 BP 6159 EP 6162 DI 10.1016/S0040-4039(99)01105-3 PG 4 WC Chemistry, Organic SC Chemistry GA 225AJ UT WOS:000081932200007 ER PT J AU Ha, T Laurence, TA Chemla, DS Weiss, S AF Ha, T Laurence, TA Chemla, DS Weiss, S TI Polarization spectroscopy of single fluorescent molecules SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SCANNING OPTICAL MICROSCOPY; INDIVIDUAL MOLECULES; ROOM-TEMPERATURE; AQUEOUS-SOLUTION; DYNAMICS; DIFFUSION; LIGHT; FLUCTUATIONS; ORIENTATION; EXCITATION AB Polarization spectroscopy of single fluorescent molecules is used to probe their rotational dynamics. When a molecule is immobilized on a dry surface, its in-plane dipole orientation is precisely determined by utilizing its transition dipole moment. An angular offset between the absorption and the emission dipoles was detected from a single fluorophore revealing its binding geometry to the surface. In an aqueous environment, DNA-tethered fluorophores display dynamics that are well-described by a hindered rotational diffusion model. A detailed description of the model is given, including calculations to estimate depolarization effects resulting from the high numerical aperture objective used to collect fluorescence photons. Protein-conjugated fluorophores display very distinct dynamics with continuous evolution of the rotational profile, possibly reflecting fluctuations in the polypeptide chain, When protein-conjugated fluorophores are allowed to freely diffuse in solution, it is possible to determine the fluorescence polarization anisotropy of each molecule that traverses the laser beam. The anisotropy values could, in principle, be used to identify conformational states of single molecules without the potential artifacts associated with surface immobilization. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM tjha@stanford.edu; sweiss@lbl.gov RI Ha, Taekjip/B-9506-2009; Laurence, Ted/E-4791-2011; weiss, shimon/B-4164-2009 OI Ha, Taekjip/0000-0003-2195-6258; Laurence, Ted/0000-0003-1474-779X; weiss, shimon/0000-0002-0720-5426 NR 50 TC 191 Z9 196 U1 2 U2 33 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD AUG 19 PY 1999 VL 103 IS 33 BP 6839 EP 6850 DI 10.1021/jp990948j PG 12 WC Chemistry, Physical SC Chemistry GA 231XA UT WOS:000082335600002 ER PT J AU Kim, KK Yokota, H Kim, SH AF Kim, KK Yokota, H Kim, SH TI Four-helical-bundle structure of the cytoplasmic domain of a serine chemotaxis receptor SO NATURE LA English DT Article ID DISULFIDE CROSS-LINKING; LIGAND-BINDING DOMAIN; ASPARTATE RECEPTOR; ESCHERICHIA-COLI; BACTERIAL CHEMOTAXIS; ALPHA-HELIX; CHEMORECEPTOR; MODEL; DIMER; MUTAGENESIS AB The bacterial chemotaxis receptors are transmembrane receptors with a simple signalling pathway which has elements relevant to the general understanding of signal recognition and transduction across membranes, how signals are relayed between molecules in a pathway, and how adaptation to a persistent signal is achieved(1). In contrast to many mammalian receptors which signal by oligomerizing upon ligand binding(2), the chemotaxis receptors are dimeric even in the absence of their ligands, and their signalling does not depend on a monomer-dimer equilibrium(3). Bacterial chemotaxis receptors are composed of a ligand-binding domain, a transmembrane domain consisting of two helices TM1 and TM2, and a cytoplasmic domain. All known bacterial chemotaxis receptors have a highly conserved cytoplasmic domain, which unites signals from different ligand domains into a single signalling pathway to flagella motors. Here we report the crystal structure of the cytoplasmic domain of a serine chemotaxis receptor of Escherichia coli, which reveals a 200 Angstrom-long coiled-coil of two antiparallel helices connected by a 'U-turn'. Two of these domains form a long, supercoiled, four-helical bundle in the cytoplasmic portion of the receptor. C1 Univ Calif Berkeley, Melvin Calvin Lab 220, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Phys Biosci Div, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Kim, SH (reprint author), Univ Calif Berkeley, Melvin Calvin Lab 220, Berkeley, CA 94720 USA. NR 30 TC 336 Z9 339 U1 2 U2 5 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 19 PY 1999 VL 400 IS 6746 BP 787 EP 792 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 228HM UT WOS:000082131100056 PM 10466731 ER PT J AU Bhattacharya, T Chandrasekharan, S Gupta, R Lee, W Sharpe, S AF Bhattacharya, T Chandrasekharan, S Gupta, R Lee, W Sharpe, S TI Non-perturbative renormalization constants using Ward identities SO PHYSICS LETTERS B LA English DT Article ID IMPROVED LATTICE QCD; NONPERTURBATIVE O(A) IMPROVEMENT; WILSON FERMIONS; CONTINUUM-LIMIT; CHIRAL-SYMMETRY; OPERATORS AB We extend the application of axial Ward identities to calculate b(A), b(P) and b(T), coefficients that give the mass dependence of the renormalization constants of the corresponding bilinear operators in the quenched theory. The extension relies on using operators with non-degenerate quark masses, It allows a complete determination of the O(a) improvement coefficients for bilinears in the quenched approximation using Ward Identities alone. Only the scale dependent normalization constants Z(P)(0) (or Z(S)(0)) and Z(T) are undetermined. We present results of a pilot numerical study using hadronic correlators. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Duke Univ, Dept Phys, Durham, NC 27705 USA. Univ Washington, Dept Phys, Seattle, WA 98195 USA. Univ Tsukuba, Ctr Computat Phys, Tsukuba, Ibaraki 3058577, Japan. RP Bhattacharya, T (reprint author), Univ Calif Los Alamos Natl Lab, MS B-285, Los Alamos, NM 87545 USA. RI Bhattacharya, Tanmoy/J-8956-2013; OI Bhattacharya, Tanmoy/0000-0002-1060-652X; Lee, Weonjong/0000-0002-9040-4134 NR 18 TC 26 Z9 26 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 19 PY 1999 VL 461 IS 1-2 BP 79 EP 88 DI 10.1016/S0370-2693(99)00796-0 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 233CL UT WOS:000082407900012 ER PT J AU Dobrescu, BA AF Dobrescu, BA TI Electroweak symmetry breaking as a consequence of compact dimensions SO PHYSICS LETTERS B LA English DT Article ID EXTRA DIMENSIONS; STANDARD MODEL; TOP-QUARK; TEV; SUPERSTRINGS; CONDENSATION; MILLIMETER AB It has been shown recently that the Higgs doublet may be composite, with the left-handed top-bottom doublet and a new right-handed anti-quark as constituents bound by some four-quark operators with non-perturbative coefficients. I show that these operators are naturally induced if there are extra spatial dimensions with a compactification scale in the multi-TeV range. The Higgs compositeness is due mainly to the Kaluza-Klein modes of the gluons, while flavor symmetry breaking may be provided by various fields propagating in the compact dimensions. I comment briefly on the embedding of this scenario in string theory. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Dobrescu, BA (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 29 TC 48 Z9 49 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 19 PY 1999 VL 461 IS 1-2 BP 99 EP 104 DI 10.1016/S0370-2693(99)00839-4 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 233CL UT WOS:000082407900015 ER PT J AU Brodsky, SJ Rathsman, J Merino, C AF Brodsky, SJ Rathsman, J Merino, C TI Odderon-Pomeron interference SO PHYSICS LETTERS B LA English DT Article ID DEEP-INELASTIC-SCATTERING; LARGE RAPIDITY GAP; ELASTIC-SCATTERING; DIFFRACTIVE PHOTOPRODUCTION; PERTURBATIVE QCD; MESON PRODUCTION; HERA; SINGULARITY; INTERCEPT; EVENTS AB We show that the asymmetry in the fractional energy of charm versus anticharm jets produced in high energy diffractive photoproduction is sensitive to the interference of the Odderon (C= -) and Pomeron (C= +) exchange amplitudes in QCD. We predict the dynamical shape of the asymmetry in a simple model and estimate its magnitude to be of the order 15% using an Odderon coupling to the proton which saturates constraints from proton-proton vs, proton-antiproton elastic scattering. Measurements of this asymmetry at HERA could provide firm experimental evidence for the presence of Odderon exchange in the high energy limit of strong interactions. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Santiago de Compostela, Dept Fis Particulas, Santiago De Compostela 15706, Spain. RP Brodsky, SJ (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 50 TC 36 Z9 36 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 19 PY 1999 VL 461 IS 1-2 BP 114 EP 122 DI 10.1016/S0370-2693(99)00807-2 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 233CL UT WOS:000082407900018 ER PT J AU Zhan, CG de Souza, ON Rittenhouse, R Ornstein, RL AF Zhan, CG de Souza, ON Rittenhouse, R Ornstein, RL TI Determination of two structural forms of catalytic bridging ligand in zinc-phosphotriesterase by molecular dynamics simulation and quantum chemical calculation SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID REACTION FIELD-THEORY; X-RAY-DIFFRACTION; BACTERIAL PHOSPHOTRIESTERASE; PSEUDOMONAS-DIMINUTA; POLARIZATION; PROTEINS; SYSTEM AB Although a three-dimensional X-ray crystal structure of zinc-substituted phosphotriesterase was recently reported, it is uncertain whether a critical bridging ligand in the active site is a water molecule or a hydroxide ion. The identity of this bridging ligand is theoretically determined by performing both molecular dynamics simulations and quantum mechanical calculations. All of the results obtained indicate that this critical ligand in the active site of the reported X-ray crystal structure is a hydroxide anion rather than a water molecule and allow us to propose a dynamic "ping-pong" model in which both kinds of structures might exist. C1 Battelle NW, Pacific NW Natl Lab, Environm Technol Div, Richland, WA 99352 USA. RP Ornstein, RL (reprint author), Battelle NW, Pacific NW Natl Lab, Environm Technol Div, Mailstop K2-21, Richland, WA 99352 USA. RI Norberto de Souza, Osmar/B-7328-2013 OI Norberto de Souza, Osmar/0000-0002-4602-1208 NR 23 TC 80 Z9 82 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD AUG 18 PY 1999 VL 121 IS 32 BP 7279 EP 7282 DI 10.1021/ja9906397 PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA 230KH UT WOS:000082250000001 ER PT J AU Burkoth, TS Benzinger, TLS Urban, V Lynn, DG Meredith, SC Thiyagarajan, P AF Burkoth, TS Benzinger, TLS Urban, V Lynn, DG Meredith, SC Thiyagarajan, P TI Self-assembly of A beta((10-35))-PEG block copolymer fibrils SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID AMYLOID FIBRIL; BETA-SHEET; FIBRILLOGENESIS; PEPTIDE C1 Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Univ Chicago, Dept Pathol, Chicago, IL 60637 USA. Argonne Natl Lab, Intense Pulse Neutron Source, Argonne, IL 60439 USA. RP Lynn, DG (reprint author), Univ Chicago, Dept Chem, 5735 S Ellis Ave, Chicago, IL 60637 USA. RI Urban, Volker/N-5361-2015 OI Urban, Volker/0000-0002-7962-3408 NR 21 TC 101 Z9 101 U1 1 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD AUG 18 PY 1999 VL 121 IS 32 BP 7429 EP 7430 DI 10.1021/ja991233x PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 230KH UT WOS:000082250000031 ER PT J AU Mao, B Gu, ZT Gorin, A Chen, JX Hingerty, BE Amin, S Broyde, S Geacintov, NE Patel, DJ AF Mao, B Gu, ZT Gorin, A Chen, JX Hingerty, BE Amin, S Broyde, S Geacintov, NE Patel, DJ TI Solution structure of the (+)-cis-anti-benzo[a]pyrene-dA ([BP]dA) adduct opposite dT in a DNA duplex SO BIOCHEMISTRY LA English DT Article ID DEOXYADENOSINE N-6-AMINO GROUP; NUCLEAR-MAGNETIC-RESONANCE; DG MISMATCH OPPOSITE; DIASTEREOMERIC BENZOPYRENE 7,8-DIOL-9,10-EPOXIDES; DOSE-DEPENDENT DIFFERENCES; NMR SOLUTION STRUCTURE; IN-VITRO REPLICATION; HAMSTER V-79 CELLS; N-RAS CODON-61; SOLUTION CONFORMATION AB Minor adducts, derived from the covalent binding of anti-benzo [a]pyrene-7,8 -dihydroxy-9,-10-epoxide to cellular DNA, may play an important role in generating mutations and initiating cancer. We have applied a combined NMR-computational approach including intensity based refinement to determine the solution structure of the minor (+)-cis-anti-[BP]dA adduct positioned opposite dT in the d(C1-T2-C3-T4-C5-[BP]A6-C7-T8-T9-C10-C11).(d(G12-G13-A14-A15-G16-T17-G18A19-G20-A21-G22) 11-mer duplex. The BP ring system is intercalated toward the 5'-side of the [BP]dA6 lesion site without disrupting the flanking Watson-Crick dC5.dG18 and [BP]dA6.dT17 base pairs. This structure of the (+)-cis-anti-[BP]dA.dT 11-mer duplex, containing a bay region benzo[a]pyrenyl [BP]dA adduct, is compared with the corresponding structure of the (+)-trans-anti-[BPh]dA.dT 11-mer duplex (Cosman et al., Biochemistry 32, 12488-12497, 1993), which contains a fjord region benzo[c]phenanthrenyl [BPh]dA adduct with the same R stereochemistry at the linkage site. The carcinogen intercalates toward the 5'-direction of the modified strand in both duplexes (the adduct is embedded within the same sequence context) with the buckling of the Watson-Crick [BP]dA6.dT17 base pair more pronounced in the (+)-cis-anti-[BP]dA.dT 11-mer duplex compared to its Watson-Crick [BPh]dA.dT17 base pair in the (+)-trans-anti- [BPh]dA.dT 11-mer duplex. The available structural studies of covalent polycyclic aromatic hydrocarbon (PAH) carcinogen-DNA adducts point toward the emergence of a general theme where distinct alignments are adopted by PAH adducts covalently linked to the N-6 Of adenine when compared to the N-2 of guanine in DNA duplexes. The [BPh]dA and [BP]dA N-6-adenine adducts intercalate their polycyclic aromatic rings into the helix without disruption of their modified base pairs. This may reflect the potential flexibility associated with the positioning of the covalent tether and the benzylic ring of the carcinogen in the sterically spacious major groove. By contrast, such an intercalation without modified base pair disruption option appears not to be available to [BP]dG N-2-guanine adducts where the covalent tether and the benzylic ring are positioned in the more sterically crowded minor groove. In the case of [BP]dG adducts, the benzopyrenyl ring is either positioned in the minor groove without base pair disruption, or if intercalated into the helix, requires disruption of the modified base pair and displacement of the bases out of the helix. C1 Mem Sloan Kettering Canc Ctr, Cellular Biochem & Biophys Program, New York, NY 10021 USA. NYU, Dept Chem, New York, NY 10003 USA. NYU, Dept Biol, New York, NY 10003 USA. Oak Ridge Natl Lab, Life Sci Res Div, Oak Ridge, TN 37831 USA. Amer Hlth Fdn, Valhalla, NY 10595 USA. RP Patel, DJ (reprint author), Mem Sloan Kettering Canc Ctr, Cellular Biochem & Biophys Program, New York, NY 10021 USA. RI Gorin, Andrey/B-1545-2014 FU NCI NIH HHS [CA-20851, CA-28038, CA-49982] NR 49 TC 33 Z9 33 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD AUG 17 PY 1999 VL 38 IS 33 BP 10831 EP 10842 DI 10.1021/bi991212f PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 231WQ UT WOS:000082334700025 PM 10451380 ER PT J AU Gu, ZT Gorin, A Krishnasamy, R Hingerty, BE Basu, AK Broyde, S Patel, DJ AF Gu, ZT Gorin, A Krishnasamy, R Hingerty, BE Basu, AK Broyde, S Patel, DJ TI Solution structure of the N-(deoxyguanosin-8-yl)-1-aminopyrene ([AP]dG) adduct opposite dA in a DNA duplex SO BIOCHEMISTRY LA English DT Article ID INDUCED FRAMESHIFT MUTAGENESIS; SALMONELLA-TYPHIMURIUM; ENVIRONMENTAL MUTAGEN; REPETITIVE SEQUENCES; NMR-SPECTROSCOPY; ESCHERICHIA-COLI; 1-NITROPYRENE; CARCINOGEN; MUTATIONS; 1-NITROSOPYRENE AB Solution structural studies have been undertaken on the aminopyrene-C-8-dG ([AP]dG) adduct in the d(CS-[AP]GG-C7).d(G16-A17-G18) sequence context in an 11-mer duplex with dA opposite [AP]dG, using proton-proton distance and intensity restraints derived from NMR data in combination with distance-restrained molecular mechanics and intensity-restrained relaxation matrix refinement calculations. The exchangeable and nonexchangeable protons of the aminopyrene and the nucleic acid were assigned following analysis of two-dimensional NMR data sets on the [AP]dG.dA 11-mer duplex in H2O and D2O solution. The broadening of several resonances within the d(G16-A17-G18) segment positioned opposite the [AP]dG6 lesion site resulted in weaker NOEs, involving these protons in the adduct duplex. Both proton and carbon NMR data are consistent with a syn glycosidic torsion angle for the [AP]dG6 residue in the adduct duplex. The aminopyrene ring of [AP]dG6 is intercalated into the DNA helix between intact Watson-Crick dC5.dG18 and dC7.dG16 base pairs and is in contact with dC5, dC7, dG16, dA17, and dG18 residues that form a hydrophobic pocket around it. The intercalated AP ring of [AP]dG6 stacks over the purine ring of dG16 and, to a lesser extent dG18, while the looped out deoxyguanosine ring of [AP]dG6 stacks over dC5 in the solution structure of the adduct duplex. The dA17 base opposite the adduct site is not looped out of the helix but rather participates in an in-plane platform with adjacent dG18 in some of the refined structures of the adduct duplex. The solution structures are quite different for the [AP]dG.dA 11-mer duplex containing the larger aminopyrene ring (reported in this study) relative to the previously published [AF]dG.dA 11-mer duplex containing the smaller aminofluorene ring (Norman et al., Biochemistry 28, 7462-7476, 1989) in the same sequence context. Both the modified syn guanine and the dA positioned opposite it are stacked into the helix with the aminofluorene chromophore displaced into the minor groove in the latter adduct duplex. By contrast, the aminopyrenyl ring participates in an intercalated base-displaced structure in the present study of the [AP]dG.dA 11-mer duplex and in a previously published study of the [AP]dG.dC 11-mer duplex (Mao et al.., Biochemistry 35, 12659-12670, 1996). Such intercalated base-displaced structures without hydrogen bonding between the [AP]dG adduct and dC or mismatched dA residues positioned opposite it, if present at a replication fork, may cause polymerase stalling and formation of a slipped intermediate that could produce frameshift mutations, the most dominant mutagenic consequence of the [AP]dG lesion. C1 Mem Sloan Kettering Canc Ctr, Cellular Biochem & Biophys Program, New York, NY 10021 USA. Univ Connecticut, Dept Chem, Storrs, CT 06269 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. NYU, Dept Biol, New York, NY 10003 USA. RP Patel, DJ (reprint author), Mem Sloan Kettering Canc Ctr, Cellular Biochem & Biophys Program, 1275 York Ave, New York, NY 10021 USA. RI Gorin, Andrey/B-1545-2014 FU NCI NIH HHS [CA-28038, CA-75449, CA-49982]; NIEHS NIH HHS [R01 ES009127] NR 52 TC 22 Z9 22 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD AUG 17 PY 1999 VL 38 IS 33 BP 10843 EP 10854 DI 10.1021/bi9912138 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 231WQ UT WOS:000082334700026 PM 10451381 ER PT J AU Gu, ZT Gorin, A Hingerty, BE Broyde, S Patel, DJ AF Gu, ZT Gorin, A Hingerty, BE Broyde, S Patel, DJ TI Solution structures of aminofluorene [AF]-stacked conformers of the syn [AF]-C-8-dG adduct positioned opposite dC or dA at a template-primer junction SO BIOCHEMISTRY LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; DNA DUPLEX; SOLUTION CONFORMATION; COMPUTATIONAL CHARACTERIZATION; CHEMICAL-STRUCTURE; BASE DISPLACEMENT; NMR-SPECTROSCOPY; ESCHERICHIA-COLI; DG OPPOSITE; MAJOR GROOVE AB A solution structural study has been undertaken on the aminofluorene-C-8-dG ([AF]dG) adduct located at a single-strand-double-strand d(A1-A2-C3-[AF] G4-C5-T6-A7-C8-C9-A10-T11-C12-C13) d(G14-G15-A16-T17-G18-G19-T20-A21-G22-N23) 13/10-mer junction (N = C or A) using proton-proton distance restraints derived from NMR data in combination with intensity-based relaxation matrix refinement computations. This single-strand-double-strand junction models one arm of a replication fork composed of a 13-mer template strand which contains the [AF]dG modification site and a 10-mer primer strand which has been elongated up to the modified guanine with either its complementary dC partner or a dA mismatch. The solution structures establish that the duplex segment retains a minimally perturbed B-DNA conformation with Watson-Crick hydrogen bonding retained up to the dC5.dG22 base pair. The guanine ring of the [AF]dG4 adduct adopts a syn glycosidic torsion angle and is displaced into the major groove when positioned opposite dC or dA residues. This base displacement of the modified guanine is accompanied by stacking of one face of the aminofluorene ring of [AF]dG4 with the dC5.dG22 base pair, while the other face of the aminofluorene ring is stacked with the purine ring of the nonadjacent dA2 residue. By contrast, the dC and dA residues opposite the junctional [AF]dG4 adduct site adopt distinctly different alignments. The dC23 residue positioned opposite the adduct site is looped out into the minor groove by the aminofluorene ring. The syn displaced orientation of the modified dG with stacking of the aminofluorene and the looped out position of the partner dC could be envisioned to cause polymerase stalling associated with subsequent misalignment leading to frameshift mutations in appropriate sequences. The dA23 residue positioned opposite the adduct site is positioned in the major groove with its purine ring aligned face down over the van der Waals surface of the major groove and its amino group directed toward the T6.A21 base pair. The Hoogsteen edge of the modified guanine of [AF]dG4 and the Watson-Crick edge of dA23 positioned opposite it are approximately coplanar and directed toward each other but are separated by twice the hydrogen-bonding distance required for pairing. This structure of [AF]dG opposite dA at a model template-primer junctional site can be compared with a previous structure of [AF]dG opposite dA within a fully paired duplex [Norman, D., Abuaf, P., Hingerty, B. E., Live, D., Grunberger, D., Broyde, S., and Patel, D. J. (1989) Biochemistry 28, 7462-7476]. The alignment of the Hoogsteen edge of [AF]dG (syn) positioned opposite the Watson-Crick edge of dA (anti) has been observed for both systems with the separation greater in the case of the junctional alignment in the model template-primer system. However, the aminofluorene ring is positioned in the minor groove in the fully paired duplex while it stacks over the junctional base pair in the template-primer system. This suggests that the syn [AF]dG opposite dA junctional alignment can be readily incorporated within a duplex by a translation of this entity toward the minor groove. C1 Mem Sloan Kettering Canc Ctr, Cellular Biochem & Biophys Program, New York, NY 10021 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. NYU, Dept Biol, New York, NY 10003 USA. RP Patel, DJ (reprint author), Mem Sloan Kettering Canc Ctr, Cellular Biochem & Biophys Program, 1275 York Ave, New York, NY 10021 USA. RI Gorin, Andrey/B-1545-2014 FU NCI NIH HHS [CA-28038, CA-49982, CA-75449] NR 52 TC 18 Z9 18 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD AUG 17 PY 1999 VL 38 IS 33 BP 10855 EP 10870 DI 10.1021/bi991266p PG 16 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 231WQ UT WOS:000082334700027 PM 10451382 ER PT J AU Geiger, HC Perlstein, J Lachicotte, RJ Wyrozebski, K Whitten, DG AF Geiger, HC Perlstein, J Lachicotte, RJ Wyrozebski, K Whitten, DG TI Self-assembly of aromatic-derivatized amphiphiles: Phenyl, biphenyl, and terphenyl fatty acids and phospholipids SO LANGMUIR LA English DT Article ID LANGMUIR-BLODGETT MULTILAYERS; MICROHETEROGENEOUS MEDIA; TRANS-STILBENE; AZOBENZENE PHOSPHOLIPIDS; BENZENE DIMER; AGGREGATE; VESICLES; PHOTOREACTIVITY; PHOTOCHEMISTRY; PHOTOPHYSICS AB This paper reports the synthesis of a series of amphiphiles (fatty acids and phosphatidylcholine derivatives) containing phenyl, biphenyl, and terphenyl chromophores inserted in the hydrocarbon chain and a study of their self-assembly in Langmuir-Blodgett films and aqueous dispersions. As observed and reported earlier for amphiphiles containing trans-stilbene, styrylthiophene, or azobenzene chromophores, several of the biphenyl and terphenyl derivatives show strong evidence of ground state association to form "H" aggregates characterized by a blue shift in absorption and a structured red-shifted fluorescence. The phenyl amphiphiles show different behavior, suggesting that, even for pure films or bilayers, there is very little or no ground state association. For the biphenyl and terphenyl phospholipids, aqueous suspensions obtained by sonication are closed bilayer vesicles similar in size to those formed from the corresponding saturated phospholipids. The overall results of the present study indicate that biphenyl and terphenyl amphiphiles undergo aggregation processes to form compact arrays formally similar to those observed with stilbene, tolan, azobenzene, and squaraine derivatives but that the aromatic-aromatic interactions are considerably weaker than those for the more extended aromatics and lead to less distortion of the assembly structure. C1 Univ Rochester, Dept Chem, Ctr Photoinduced Charge Transfer, Rochester, NY 14627 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Whitten, DG (reprint author), Univ Rochester, Dept Chem, Ctr Photoinduced Charge Transfer, Rochester, NY 14627 USA. NR 38 TC 20 Z9 20 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD AUG 17 PY 1999 VL 15 IS 17 BP 5606 EP 5616 DI 10.1021/la990124t PG 11 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 228EV UT WOS:000082124900029 ER PT J AU Goncharov, AA Protsenko, IM Yushkov, GY Brown, IG AF Goncharov, AA Protsenko, IM Yushkov, GY Brown, IG TI Focusing of high-current, large-area, heavy-ion beams with an electrostatic plasma lens SO APPLIED PHYSICS LETTERS LA English DT Article AB We report on measurements of the focusing of high-current, large-area beams of heavy metal ions using an electrostatic plasma lens. Tantalum ion beams were formed by a repetitively pulsed vacuum arc ion source, with energy in the 100 keV range, current up to 0.5 A, initial beam diameter 10 cm, and pulse length 250 mu s. The plasma lens was of internal diameter 10 cm and length 20 cm, and had nine electrostatic ring electrodes with potential applied to the central electrode of up to 7 kV, in the presence of a pulsed magnetic field of up to 800 G. The current-density profile of the downstream, focused, ion beam was measured with a radially moveable, magnetically suppressed, Faraday cup. The tantalum ion-beam current density at the focus was compressed by a factor of up to 30. The results are important in that they provide a demonstration of a means of manipulating high-current ion beams without associated space-charge blowup. (C) 1999 American Institute of Physics. [S0003-6951(99)01333-9]. C1 NASU, Inst Phys, UA-252650 Kiev 39, Ukraine. Russian Acad Sci, Inst High Current Elect, Tomsk 634055, Russia. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Goncharov, AA (reprint author), NASU, Inst Phys, 46 Prospect Nauki, UA-252650 Kiev 39, Ukraine. RI Yushkov, Georgy/O-8024-2015 OI Yushkov, Georgy/0000-0002-7615-6058 NR 9 TC 30 Z9 30 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 16 PY 1999 VL 75 IS 7 BP 911 EP 913 DI 10.1063/1.124551 PG 3 WC Physics, Applied SC Physics GA 224YZ UT WOS:000081928700010 ER PT J AU Zhao, YC Aziz, MJ Gossmann, HJ Mitha, S Schiferl, D AF Zhao, YC Aziz, MJ Gossmann, HJ Mitha, S Schiferl, D TI Activation volume for antimony diffusion in silicon and implications for strained films SO APPLIED PHYSICS LETTERS LA English DT Article AB The diffusivity of Sb in Si is retarded by pressure, characterized at 860 degrees C by an activation volume of V*=+0.07 +/- 0.02 times the Si atomic volume. V* is close to values inferred from atomistic calculations for a vacancy mechanism. Our results for hydrostatic pressure are used to predict the effect of biaxial strain on Sb diffusion. The prediction matches measured behavior for Sb diffusion in biaxially strained Si and Si-Ge films. This work lends additional support to the predominance of the vacancy mechanism for Sb diffusion and demonstrates the first steps in the development of a capability for predicting the effect of nonhydrostatic stress on diffusion. (C) 1999 American Institute of Physics. [S0003-6951(99)03233-7]. C1 Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Charles Evans & Associates, Redwood City, CA 94063 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Zhao, YC (reprint author), Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. RI Lujan Center, LANL/G-4896-2012 NR 22 TC 18 Z9 18 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 16 PY 1999 VL 75 IS 7 BP 941 EP 943 DI 10.1063/1.124561 PG 3 WC Physics, Applied SC Physics GA 224YZ UT WOS:000081928700020 ER PT J AU Poles, E Selmarten, DC Micic, OI Nozik, AJ AF Poles, E Selmarten, DC Micic, OI Nozik, AJ TI Anti-Stokes photoluminescence in colloidal semiconductor quantum dots SO APPLIED PHYSICS LETTERS LA English DT Article AB We report anti-Stokes photoluminescence (photon energy up-conversion) from size-quantized CdSe and InP nanocrystalline colloids. The observed up-conversion is highly efficient and occurs at very low excitation intensities. With low temperatures the intensity of the up-converted photoluminescence decreases while that of the usual Stokes photoluminescence increases; the up-converted photoluminescence is also restricted to energies corresponding to the band gaps of the quantum dots that are present in the colloid ensemble. The anti-Stokes photoluminescence is explained by a model that involves surface states. (C) 1999 American Institute of Physics. [S0003-6951(99)03033-8]. C1 Natl Renewable Energy Lab, Ctr Basic Sci, Golden, CO 80401 USA. RP Poles, E (reprint author), Natl Renewable Energy Lab, Ctr Basic Sci, Golden, CO 80401 USA. RI Nozik, Arthur/A-1481-2012; Nozik, Arthur/P-2641-2016 NR 19 TC 81 Z9 81 U1 2 U2 16 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 16 PY 1999 VL 75 IS 7 BP 971 EP 973 DI 10.1063/1.124570 PG 3 WC Physics, Applied SC Physics GA 224YZ UT WOS:000081928700030 ER PT J AU Thiesen, J Iwaniczko, E Jones, KM Mahan, A Crandall, R AF Thiesen, J Iwaniczko, E Jones, KM Mahan, A Crandall, R TI Growth of epitaxial silicon at low temperatures using hot-wire chemical vapor deposition SO APPLIED PHYSICS LETTERS LA English DT Article AB We demonstrate epitaxial silicon growth of 8 A/s at temperatures as low as 195 degrees C, using hot-wire chemical vapor deposition. Characterization by transmission electron microscopy shows epitaxial layers of Si. We briefly discuss various aspects of the process parameter space. Finally, we consider differences in the chemical kinetics of this process when compared to other epitaxial deposition techniques. (C) 1999 American Institute of Physics. [S0003-6951(99)04233-3]. C1 Univ Colorado, Dept Elect Engn, Boulder, CO 80309 USA. Natl Renewable Energy Lab, NREL, Golden, CO USA. RP Thiesen, J (reprint author), Univ Colorado, Dept Elect Engn, Boulder, CO 80309 USA. NR 20 TC 49 Z9 51 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 16 PY 1999 VL 75 IS 7 BP 992 EP 994 DI 10.1063/1.124576 PG 3 WC Physics, Applied SC Physics GA 224YZ UT WOS:000081928700037 ER PT J AU Lippert, T Gerber, T Wokaun, A Funk, DJ Fukumura, H Goto, M AF Lippert, T Gerber, T Wokaun, A Funk, DJ Fukumura, H Goto, M TI Single pulse nm-size grating formation in polymers using laser ablation with an irradiation wavelength of 355 nm SO APPLIED PHYSICS LETTERS LA English DT Article AB Laser ablation at 355 nm of a specially designed polymer was used as a true single step dry-etching process to create a two-beam interference grating. Gratings with groove spacings of 180 and 1090 nm were created with single laser pulses. Moreover, by varying the laser fluence and/or the angle between the two beams, variable modulation frequencies (depth/spacing) could be obtained. Additional pulses deteriorated the grating quality, demonstrating the importance of the single pulse approach. (C) 1999 American Institute of Physics. [S0003-6951(99)00333-2]. C1 Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Japan Atom Energy Res Inst, Adv Sci Res Ctr, Neyagawa, Osaka 572, Japan. Tohoku Univ, Dept Chem, Sendai, Miyagi 9808578, Japan. RP Lippert, T (reprint author), Paul Scherrer Inst, CH-5232 Villigen, Switzerland. EM lippert@psi.ch RI Fukumura, Hiroshi/G-4535-2011; Lippert, Thomas/N-2423-2016; OI Gerber, Thomas/0000-0001-7027-0477 NR 23 TC 35 Z9 35 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 16 PY 1999 VL 75 IS 7 BP 1018 EP 1020 DI 10.1063/1.124584 PG 3 WC Physics, Applied SC Physics GA 224YZ UT WOS:000081928700046 ER PT J AU Artunc, N Elgun, N Vizir, A Brown, I Bo, S Tarhan, E AF Artunc, N Elgun, N Vizir, A Brown, I Bo, S Tarhan, E TI Electrical and structural properties of Cr ion-implanted thin Au films SO MATERIALS CHEMISTRY AND PHYSICS LA English DT Article DE magnetron sputtering; ion implantation; transmission electron microscopy; Cr ion-implanted Au films; structural and electrical properties ID RESISTIVITY; TEMPERATURE; CHROMIUM; STRAIN AB Cr metal ions with doses of 1 x 10(14)-1 x 10(15) ions/cm(2) have been implanted at 125 keV into thin Au films prepared by DC magnetron sputtering. Electron diffraction patterns have revealed that ail the films remain in the f.c.c. structure, indicating the formation of Au-Cr solid solution. The resistivity of the films were studied in the temperature range 100-330 K. The results show increase in the resistivity with respect to the unimplanted him as a result of the implantation. Some samples show two different types of resistivity anomalies, which are attributed to the occurrence of the antiferromagnetically incommensurate spin density wave and commensurate spin density wave structures, (C) 1999 Elsevier Science S.A. All rights reserved. C1 Ege Univ, Fac Sci, Dept Phys, TR-35100 Izmir, Turkey. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Middle E Tech Univ, Dept Met & Mat Engn, TR-06531 Ankara, Turkey. RP Artunc, N (reprint author), Ege Univ, Fac Sci, Dept Phys, TR-35100 Izmir, Turkey. RI Vizir, Alexey/R-2139-2016 OI Vizir, Alexey/0000-0002-9563-8650 NR 18 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0254-0584 J9 MATER CHEM PHYS JI Mater. Chem. Phys. PD AUG 16 PY 1999 VL 60 IS 2 BP 182 EP 187 DI 10.1016/S0254-0584(99)00087-5 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA 219AU UT WOS:000081585900010 ER PT J AU Ronning, F Kim, C Shen, ZX AF Ronning, F Kim, C Shen, ZX TI Angle-resolved photoemission electron spectroscopy reveals a Fermi surface remnant with a d-wave like dispersion in the Mott insulator, Ca2CuO2Cl2 SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 7th NEC Symposium on Fundamental Approaches to New Material Phases - Phase Control in Spin-Charge-Orbital Complex Systems CY OCT 11-15, 1998 CL NASU, JAPAN SP NEC Corp DE Fermi surface; Mott insulator; angle-resolved photoemission spectroscopy ID NORMAL-STATE; BI2SR2CACU2O8+DELTA; MODEL; SUPERCONDUCTORS; MOMENTUM; GAP AB We report angle-resolved photoemission measurements on a Mott insulating CuO2, plane compound Ca2CuO2,Cl-2,. This material is a parent compound to the high-T-c, superconductors. We observe a loss in spectral weight of the lowest energy feature as it crosses the approximate position where band theory predicts the existence of the Fermi surface. Complimented with an analysis from metallic Bi2Sr2CaCu2O8, this suggests that the loss of spectral weight is due to the remnants of the non-interacting Fermi surface that is destroyed in the insulator. Further analysis shows a d-wave like dispersion along this 'Fermi surface' contour. This suggests that the d-wave like dispersion seen in the high-energy pseudogap is a remnant property of the insulator. (C) 1999 Published by Elsevier Science S.A. All rights reserved. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Shen, ZX (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. NR 17 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD AUG 16 PY 1999 VL 63 IS 1-2 BP 17 EP 21 DI 10.1016/S0921-5107(99)00046-X PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 224FX UT WOS:000081887800005 ER PT J AU Keimer, B Casa, D Kiryukhin, V Saleh, OA Hill, JP Tomioka, Y Tokura, Y AF Keimer, B Casa, D Kiryukhin, V Saleh, OA Hill, JP Tomioka, Y Tokura, Y TI X-Ray effects in charge-ordered manganites: a magnetic mechanism of persistent photoconductivity SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 7th NEC Symposium on Fundamental Approaches to New Material Phases - Phase Control in Spin-Charge-Orbital Complex Systems CY OCT 11-15, 1998 CL NASU, JAPAN SP NEC Corp DE colossal magnetoresistance; persistent photoconductivity; hot electrons; X-ray diffraction ID NEUTRON-DIFFRACTION; METAL TRANSITION; INSULATOR; PR0.7CA0.3MNO3; PR1-XCAXMNO3; JUNCTIONS; STATES AB Charge-ordered manganites of composition Pr1-x(Ca1-ySry),MnO3 exhibit persistent photo-conductivity when illuminated by X-rays. We review transport and X-ray diffraction data as functions of X-ray exposure, magnetic field, and temperature which shed light on the origin of this unusual behavior. The experimental evidence suggests that the mechanism primarily involves a ferromagnetic polarization of local spins by hot electrons generated by the X-rays. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. JRCAT, Tsukuba, Ibaraki 305, Japan. Univ Tokyo, Dept Appl Phys, Tokyo 113, Japan. RP Keimer, B (reprint author), Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. RI Saleh, Omar/B-5014-2008; Tokura, Yoshinori/C-7352-2009; Casa, Diego/F-9060-2016 OI Saleh, Omar/0000-0002-9197-4024; NR 23 TC 2 Z9 2 U1 1 U2 6 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD AUG 16 PY 1999 VL 63 IS 1-2 BP 30 EP 35 DI 10.1016/S0921-5107(99)00048-3 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 224FX UT WOS:000081887800007 ER PT J AU Yoshizawa, H Kajimoto, R Kawano, H Fernandez-Baca, JA Tomioka, Y Kuwahara, H Tokura, Y AF Yoshizawa, H Kajimoto, R Kawano, H Fernandez-Baca, JA Tomioka, Y Kuwahara, H Tokura, Y TI Magnetic ordering and spin fluctuations in nearly half-doped manganites SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 7th NEC Symposium on Fundamental Approaches to New Material Phases - Phase Control in Spin-Charge-Orbital Complex Systems CY OCT 11-15, 1998 CL NASU, JAPAN SP NEC Corp DE half-doped manganite; orbital ordering ID METAL-INSULATOR-TRANSITION; NEUTRON-DIFFRACTION; MANGANESE OXIDES; PR0.7CA0.3MNO3; FIELD; PR1-XCAXMNO3; TEMPERATURE; THERMOPOWER; FERROMAGNET; TRANSPORT AB We discuss unusual behavior discovered in spin dynamics in the nearly half-doped manganite systems. Nd0.45Sr0.55MnO3 is a metallic antiferromagnet, and exhibits very anisotropic spin wave dispersion relations. The ferromagnetic (FM) state of Pr1/2Sr1/2MnO3 and Nd1/2Sr1/2MnO3 also exhibit dear anisotropic dispersion relations. Such anisotropy reflects the underlying d(x(2) - y(2))-type Orbital ordering. We also demonstrate that the high temperature paramagnetic state without charge ordering in doped manganites is characterized by the FM spin fluctuations with an anomalously small energy scale for a wide range of doping concentrations. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Univ Tokyo, ISSP, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510918, Japan. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Joint Res Ctr Atom Technol, Tsukuba, Ibaraki 3058562, Japan. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 1138656, Japan. RP Univ Tokyo, ISSP, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. RI Tokura, Yoshinori/C-7352-2009; Fernandez-Baca, Jaime/C-3984-2014; Kawano-Furukawa, Hazuki/M-7695-2016; Kawano-Furukawa, Hazuki/M-7646-2016 OI Fernandez-Baca, Jaime/0000-0001-9080-5096; Kawano-Furukawa, Hazuki/0000-0003-4713-3727; Kawano-Furukawa, Hazuki/0000-0003-4713-3727 NR 35 TC 8 Z9 8 U1 1 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD AUG 16 PY 1999 VL 63 IS 1-2 BP 125 EP 132 DI 10.1016/S0921-5107(99)00062-8 PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 224FX UT WOS:000081887800021 ER PT J AU Berger, A Osgood, RM Jiang, JS Miller, DJ Mitchell, JF Bader, SD AF Berger, A Osgood, RM Jiang, JS Miller, DJ Mitchell, JF Bader, SD TI Role of intergrowths in the properties of the naturally layered manganites SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 7th NEC Symposium on Fundamental Approaches to New Material Phases - Phase Control in Spin-Charge-Orbital Complex Systems CY OCT 11-15, 1998 CL NASU, JAPAN SP NEC Corp DE intergrowth; colossal magnetoresistance; layered materials; manganites; magnetic measurements ID T-C; GIANT MAGNETORESISTANCE; LA1.2SR1.8MN2O7; CRYSTAL; OXIDES; STATE AB The structural and magnetic properties of the two-layered Ruddlesden-Popper phase SrO(La1-xSrxMnO3)(2) with x = 0.3 and x = 0.4 are investigated. These naturally layered manganites exhibit a colossal magnetoresistance, a magnetic anisotropy which is strongly composition-dependent, almost no remanence, and a non-vanishing magnetization in a extended temperature range above the Curie temperature (T-C) The magnetization in this temperature range is not intrinsic to the crystal, but is attributed to intergrowths. These two-dimensional (2D) lattice imperfections consist of additional or missing SrO layers and have been observed in transmission electron micrographs. The magnetic properties of the intergrowths differ from the bulk crystal which results in unusual magnetic behavior. (C) 1999 Published by Elsevier Science S.A. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Bader, SD (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013; Berger, Andreas/D-3706-2015 OI Berger, Andreas/0000-0001-5865-6609 NR 15 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD AUG 16 PY 1999 VL 63 IS 1-2 BP 133 EP 139 DI 10.1016/S0921-5107(99)00063-X PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 224FX UT WOS:000081887800022 ER PT J AU Pinkenburg, C Ajitanand, NN Alexander, JM Anderson, M Best, D Brady, FP Case, T Caskey, W Cebra, D Chance, JL Chung, P Cole, B Crowe, K Das, AC Draper, JE Elmaani, A Gilkes, ML Gushue, S Heffner, M Hirsch, AS Hjort, EL Huo, L Justice, M Kaplan, M Keane, D Kintner, JC Klay, J Krofcheck, D Lacey, RA Lauret, J Law, C Lisa, MA Liu, H Liu, YM McGrath, R Milosevich, Z Odyniec, G Olson, DL Panitkin, SY Porile, NT Rai, G Ritter, HG Romero, JL Scharenberg, R Schroeder, L Srivastava, B Stone, NTB Symons, TJM Whitfield, J Wienold, T Witt, R Wood, L Zhang, WN AF Pinkenburg, C Ajitanand, NN Alexander, JM Anderson, M Best, D Brady, FP Case, T Caskey, W Cebra, D Chance, JL Chung, P Cole, B Crowe, K Das, AC Draper, JE Elmaani, A Gilkes, ML Gushue, S Heffner, M Hirsch, AS Hjort, EL Huo, L Justice, M Kaplan, M Keane, D Kintner, JC Klay, J Krofcheck, D Lacey, RA Lauret, J Law, C Lisa, MA Liu, H Liu, YM McGrath, R Milosevich, Z Odyniec, G Olson, DL Panitkin, SY Porile, NT Rai, G Ritter, HG Romero, JL Scharenberg, R Schroeder, L Srivastava, B Stone, NTB Symons, TJM Whitfield, J Wienold, T Witt, R Wood, L Zhang, WN TI Elliptic flow: Transition from out-of-plane to in-plane emission in Au plus Au collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; RELATIVISTIC NUCLEAR COLLISIONS; COLLECTIVE EXPANSION; AU+AU COLLISIONS; SIGNATURE; EQUATION; MOTION; STATE AB We have measured the proton elliptic flow excitation function for the Au + Au system spanning the beam energy range (2-8)A GeV. The excitation function shows a transition from negative to positive elliptic flow at a beam energy, E-tr similar to 4A GeV. Detailed comparisons with calculations from a relativistic Boltzmann equation are presented. The comparisons suggest a softening of the nuclear equation of state from a stiff form (K similar to 380 MeV) at low beam energies (E-beam less than or equal to 2A GeV) to a softer form (K similar to 210 MeV) at higher energies (E-beam 4A GeV) where the calculated baryon density rho similar to 4 rho(0). C1 SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Phys, Stony Brook, NY 11794 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Ohio State Univ, Columbus, OH 43210 USA. Kent State Univ, Kent, OH 44242 USA. Univ Calif Davis, Davis, CA 95616 USA. Michigan State Univ, E Lansing, MI 48824 USA. Purdue Univ, W Lafayette, IN 47907 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Ecole Mines, SUBATECH, F-44070 Nantes, France. Univ Auckland, Auckland 1, New Zealand. Columbia Univ, New York, NY 10027 USA. St Marys Coll, Moraga, CA 94575 USA. Harbin Inst Technol, Harbin 150001, Peoples R China. RP Pinkenburg, C (reprint author), SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. RI Witt, Richard/H-3560-2012 NR 25 TC 128 Z9 131 U1 0 U2 1 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 AUG 16 PY 1999 VL 83 IS 7 BP 1295 EP 1298 DI 10.1103/PhysRevLett.83.1295 PG 4 WC Physics, Multidisciplinary SC Physics GA 227EY UT WOS:000082066600006 ER PT J AU Sadigh, B Asta, M Ozolins, V Schmid, AK Bartelt, NC Quong, AA Hwang, RQ AF Sadigh, B Asta, M Ozolins, V Schmid, AK Bartelt, NC Quong, AA Hwang, RQ TI Short-range order and phase stability of surface alloys: PdAu on Ru(0001) SO PHYSICAL REVIEW LETTERS LA English DT Article ID SYSTEMS AB Structural and thermodynamic properties of thermally equilibrated Pd-Au/Ru(0001) surface alloys are studied within the framework of lattice models based upon first-principles total energy calculations and scanning-tunneling-microscopy imaging of atomic structure. Pd-rich alloys form pseudomorphic solid-solution phases with pronounced chemical short-range order (SRO), consistent with the prediction of a low-temperature order-disorder transition to a (root 3 x root 3)-R30 degrees ground state structure. Calculated and measured SRO parameters are found to be in excellent agreement and are quantitatively described by a lattice-model Hamiltonian dominated by short-ranged interactions. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Sadigh, B (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Ozolins, Vidvuds/D-4578-2009 NR 23 TC 34 Z9 34 U1 1 U2 7 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 AUG 16 PY 1999 VL 83 IS 7 BP 1379 EP 1382 DI 10.1103/PhysRevLett.83.1379 PG 4 WC Physics, Multidisciplinary SC Physics GA 227EY UT WOS:000082066600027 ER PT J AU Harrison, N AF Harrison, N TI Destabilization of a charge-density wave by an oscillatory chemical potential SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMI-SURFACE TOPOLOGY; LOW-TEMPERATURE STATE; HIGH MAGNETIC-FIELDS; ORGANIC CONDUCTOR; QUANTUM OSCILLATIONS; BEDT-TTF; ALPHA-(BEDT-TTF)(2)KHG(SCN)(4); MAGNETOTRANSPORT; BREAKDOWN; BIS(ETHYLENEDITHIO)TETRATHIAFULVALENE AB The influence of an oscillatory chemical potential <(mu)over tilde> within the gap equation of a commensurate charge-density wave (CDW) is shown to lead to a new type of quantum oscillatory effect in the susceptibility of the nested one-dimensional sheets, with frequency exactly double that of the two-dimensional pocket from which oscillations in <(mu)over tilde> originate. On approaching the Pauli paramagnetic limit, <(mu)over tilde> further leads to a cascade of multiple first-order phase transitions between CDW and normal metallic phases. These ideas are applied to alpha-(BEDT-TTF)(2)MHg(SCN)(4) charge-transfer salts. C1 Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Natl High Magnet Field Lab, MS-E536, Los Alamos, NM 87545 USA. NR 35 TC 38 Z9 38 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 16 PY 1999 VL 83 IS 7 BP 1395 EP 1398 DI 10.1103/PhysRevLett.83.1395 PG 4 WC Physics, Multidisciplinary SC Physics GA 227EY UT WOS:000082066600031 ER PT J AU Bender, CM Cooper, F Meisinger, PN Savage, VM AF Bender, CM Cooper, F Meisinger, PN Savage, VM TI Variational ansatz for PJ-symmetric quantum mechanics SO PHYSICS LETTERS A LA English DT Article AB A variational calculation of the energy levels of the class of PJ-invariant quantum mechanical models described by the non-Hermitian Hamiltonian H = p(2) - (ix)(N) with N positive and x complex is presented. The energy levels are determined by finding the stationary points of the functional [H](a,b,c) = (integral(C)dx psi(x) H psi(x))/(integral(C)dx psi(2)(x)), where psi(x) = (ix)(c)exp(a(ix)(b)) is a three-parameter class of PJ-invariant trial wave functions. The integration contour C used to define [H](a,b,c) lies inside a wedge in the complex-x plane in which the wave function falls off exponentially at infinity. Rather than having a local minimum the functional has a saddle point in the three-parameter (a,b,c)-space. At this saddle point the numerical prediction for the ground-state energy is extremely accurate for a wide range of N. The methods of supersymmetric quantum mechanics are used to determine approximate wave functions and energy eigenvalues of the excited states of this class of non-Hermitian Hamiltonians. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. Boston Coll, Dept Phys, Chestnut Hill, MA 02167 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Bender, CM (reprint author), Washington Univ, Dept Phys, St Louis, MO 63130 USA. NR 7 TC 56 Z9 56 U1 0 U2 4 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 AUG 16 PY 1999 VL 259 IS 3-4 BP 224 EP 231 DI 10.1016/S0375-9601(99)00468-5 PG 8 WC Physics, Multidisciplinary SC Physics GA 229YX UT WOS:000082224700010 ER PT J AU Bhagat, SM Lofland, SE Mitchell, JF AF Bhagat, SM Lofland, SE Mitchell, JF TI Magnetic resonance in the layered manganite La1.2Sr1.8Mn2O7 SO PHYSICS LETTERS A LA English DT Article ID ELECTRON-SPIN-RESONANCE; FERROMAGNETIC-RESONANCE; T-C AB We present electron spin resonance measurements on single crystals of La1.2Sr1.8Mn2O7. A well-resolved multiline spectrum is observed. There is one paramagnetic resonance line for temperatures above the ordering temperatures. The other lines turn out to arise from a small (< 0.1%) volume fraction of intergrowths. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Bhagat, SM (reprint author), Univ Maryland, Dept Phys, College Pk, MD 20742 USA. OI Lofland, Samuel/0000-0002-1024-5103 NR 11 TC 10 Z9 10 U1 1 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 AUG 16 PY 1999 VL 259 IS 3-4 BP 326 EP 328 DI 10.1016/S0375-9601(99)00438-7 PG 3 WC Physics, Multidisciplinary SC Physics GA 229YX UT WOS:000082224700026 ER PT J AU Ibrahim, MA Lee, BG Park, NG Pugh, JR Eberl, DD Frank, AJ AF Ibrahim, MA Lee, BG Park, NG Pugh, JR Eberl, DD Frank, AJ TI Synthesis of new oligothiophene derivatives and their intercalation compounds: orientation effects SO SYNTHETIC METALS LA English DT Article DE thiophene oligomers; intercalation; nanocomposites; orientation effects ID TRANSITION-METAL DICHALCOGENIDES; CONDUCTIVE POLYMER; PHOTOINDUCED ABSORPTION; ELECTROACTIVE POLYMERS; V2O5 XEROGELS; SEXITHIOPHENE; ANILINE; NANOCOMPOSITES; POLYANILINE; MOS2 AB The orientation dependence of intercalated oligothiophene derivatives in vermiculite and metal disulfides MS2 (M = Mo, Ti and Zr) on the pendant group on the thiophene ring and the host material was studied by X-ray diffraction (XRD) and solid state nuclear magnetic resonance spectroscopy. Amino and nitro derivatives of bi-, ter- and quarter-thiophenes were synthesized for the first time. The amino-oligothiophenes were intercalated into vermiculite by an exchange reaction with previously intercalated octadecylammonium vermiculite and into MS2 by the intercalation-exfoliation technique. Analysis of the XRD data indicates that a monolayer of amino-oligothiophene orients perpendicularly to the silicate surface in vermiculite and lies flat in the van der Waals gap of MS2. (C) 1999 Published by Elsevier Science S.A. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Chosun Univ, Dept Chem, Kwangju 501759, South Korea. Harrell Ind, Rock Hill, SC 29715 USA. US Geol Survey, Boulder, CO 80303 USA. RP Frank, AJ (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI Park, Nam-Gyu/F-2477-2014 NR 63 TC 29 Z9 29 U1 1 U2 16 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD AUG 16 PY 1999 VL 105 IS 1 BP 35 EP 42 DI 10.1016/S0379-6779(99)00037-5 PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA 212GL UT WOS:000081208900007 ER PT J AU Geiser, U Mercuri, ML Parakka, JP AF Geiser, U Mercuri, ML Parakka, JP TI Bis[bis(triphenylphosphoranylidene)-ammonium] mu-tetrathiaoxalato-bis[(2-thioxo-1,3-dithiole-4,5-dithiolato)nickelate( II)] SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID DMIT; COMPLEXES AB The binuclear complex anion in [(C6H5)(6)P2N](2)[(C3S5)Ni(C2S4)Ni(C3S5)], conventionally abbreviated (PPN)(2)[(dmit)Ni(tto)Ni(dmit)], where PPN is bis(triphenylphosphoranylidene)ammonium, dmit is 2-thioxo-1,3-dithiole-4,5-dithiolate and tto is tetrathiaoxalate, is centrosymmetric and essentially planar, except for a small twist of 2.7(1)degrees at the Ni centers. The bond lengths [average Ni-S distance 2.166(8) Angstrom] and angles are comparable to those reported elsewhere for other salts of the component ions. The crystal packing and the charge state of the complex anion are not favorable for electrical conduction. The binuclear complex anion was synthesized by a simpler method than that published previously. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Cagliari, Dipartimento Chim & Tecnol Inorgan & Met Organ, I-09124 Cagliari, Italy. RP Geiser, U (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 9 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 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD AUG 15 PY 1999 VL 55 BP 1253 EP 1255 DI 10.1107/S0108270199004692 PN 8 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 229QU UT WOS:000082206700026 ER PT J AU Gordon, PL Thompson, JA Watkin, JG Burns, CJ Sauer, NN Scott, BL AF Gordon, PL Thompson, JA Watkin, JG Burns, CJ Sauer, NN Scott, BL TI Tetrachlorotetrakis(propan-2-ol)uranium(IV) and tetrachlorotetrakis(propan-2-ol)thorium(IV) SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID DISSOLUTION; 2-PROPANOL; IODINE AB The title complexes, [UCl4(C3H8O)(4)] and [ThCl4(C3H8O)(4)], are isomorphous and crystallize in the tetragonal space group I4(1)/a. The molecules have approximate dodecahedral symmetry and occupy sites of 4 symmetry. Principal bond lengths include U-Cl = 2.6478(10), U-O = 2.478(3), Th-Cl = 2.7066(8) and Th-O = 2.515 (2) Angstrom. C1 Callaway Golfball Co, Carlsbad, CA 92008 USA. PolyIonix Separat Technol Inc, Dayton, NJ 08810 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gordon, PL (reprint author), Callaway Golfball Co, 2285 Rutherford Rd, Carlsbad, CA 92008 USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 17 TC 4 Z9 4 U1 1 U2 3 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 AUG 15 PY 1999 VL 55 BP 1275 EP 1278 DI 10.1107/S0108270199004898 PN 8 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 229QU UT WOS:000082206700035 ER PT J AU Buchholz, BA Fultz, E Haack, KW Vogel, JS Gilman, SD Gee, SJ Hammock, BD Hui, XY Wester, RC Maibach, HI AF Buchholz, BA Fultz, E Haack, KW Vogel, JS Gilman, SD Gee, SJ Hammock, BD Hui, XY Wester, RC Maibach, HI TI HPLC-accelerator MS measurement of atrazine metabolites in human urine after dermal exposure SO ANALYTICAL CHEMISTRY LA English DT Article ID ACID AB Metabolites of atrazine were measured in human urine after dermal exposure using HPLC to separate and identify metabolites and accelerator mass spectrometry (AMS) to quantify them, Ring-labeled [C-14]atrazine was applied for 24 h with a dermal patch to human volunteers at low (0.167 mg, 6.45 mu Ci) and high (1.98 mg, 24.7 mu Ci) doses. Urine was collected for 7 days. The mine was centrifuged to remove solids, and the supernatant was measured by liquid scintillation counting prior to injection on the HPLC to ensure that <0.17 Po (4.5 pCi) was injected on the column. A reversed-phase gradient of 0.1% acetic acid in water and 0.1% acetic acid in acetonitrile became less polar with increasing time and separated the parent compound and major atrazine metabolites over 31 min on an octadecylsilane column. Peaks were identified by coelution with known standards. Elution fractions were collected in 1-min increments; half of each fraction was analyzed by AMS to obtain limits of quantitation of 14 amol. Mercapturate metabolites of atrazine and dealkylated atrazine dominated the early metabolic time points, accounting for similar to 90% of the 14C in the urine. No parent compound was detected. The excreted atrazine metabolites became:more polar with increasing time, and an unidentified polar metabolite that was present in all samples became as prevalent as any of the known ring metabolites several days after the dose was delivered. Knowledge of metabolite dynamics is crucial to developing useful assays for monitoring atrazine exposure in agricultural workers. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. Univ Calif Davis, Dept Entomol, Davis, CA 95616 USA. Univ Calif Davis, Dept Environm Toxicol, Davis, CA 95616 USA. Univ Calif San Francisco, Dept Dermatol, San Francisco, CA 94143 USA. RP Buchholz, BA (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. RI Buchholz, Bruce/G-1356-2011; Gilman, Samuel/D-1635-2016 OI Gilman, Samuel/0000-0001-7208-3894 FU NIEHS NIH HHS [R01 ES09690-01, P42 ES04699, R01 ES02710] NR 25 TC 76 Z9 76 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 15 PY 1999 VL 71 IS 16 BP 3519 EP 3525 DI 10.1021/ac990152g PG 7 WC Chemistry, Analytical SC Chemistry GA 227HM UT WOS:000082075100029 PM 10464479 ER PT J AU Thomas, RC Hierlemann, A Staton, AW Hill, M Ricco, AJ AF Thomas, RC Hierlemann, A Staton, AW Hill, M Ricco, AJ TI Reflectance infrared spectroscopy on operating surface acoustic wave chemical sensors during exposure to gas-phase analytes SO ANALYTICAL CHEMISTRY LA English DT Article ID EXTERNAL REFLECTION; MONOLAYER; MODULATION; DEVICES; DESIGN; FILMS AB Instrumentation, software, and a specialized device were developed to combine surface acoustic wave (SAW) sensor measurements with direct, in situ Fourier transform infrared external-reflectance spectroscopy (FT-IR-ERS). Probing surface-confined sensing films with molecularly specific IR spectroscopy during analyte exposure characterizes in unprecedented detail the interactions between sorptive SAW coatings and gaseous analytes. The unique device and measurement system are described. The power of the combined measurements is demonstrated by SAW/FT-IR-ERS responses to several organic analytes interacting with a conventional organic polymer, a transition-metal-coordinating self-assembled alkanethiol monolayer, and a "molecular cage" film based on a cyclodextrin. C1 Sandia Natl Labs, Microsensor Res & Dev Dept, Albuquerque, NM 87185 USA. RP Thomas, RC (reprint author), Eltron Res Inc, 5660 Airport Blvd, Boulder, CO 80301 USA. RI Hierlemann, Andreas/A-7046-2008; Ricco, Antonio/A-5273-2010; OI Hierlemann, Andreas/0000-0002-3838-2468; Ricco, Antonio/0000-0002-2355-4984 NR 33 TC 8 Z9 11 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 15 PY 1999 VL 71 IS 16 BP 3615 EP 3621 DI 10.1021/ac981447h PG 7 WC Chemistry, Analytical SC Chemistry GA 227HM UT WOS:000082075100044 ER PT J AU Matthews, DC Appelbaum, FR Eary, JF Fisher, DR Durack, LD Hui, TE Martin, PJ Mitchell, D Press, OW Storb, R Bernstein, ID AF Matthews, DC Appelbaum, FR Eary, JF Fisher, DR Durack, LD Hui, TE Martin, PJ Mitchell, D Press, OW Storb, R Bernstein, ID TI Phase I study of I-131-anti-CD45 antibody plus cyclophosphamide and total body irradiation for advanced acute leukemia and myelodysplastic syndrome SO BLOOD LA English DT Article ID B-CELL LYMPHOMA; NON-HODGKINS-LYMPHOMA; RADIOLABELED MONOCLONAL-ANTIBODIES; ALLOGENEIC MARROW TRANSPLANTATION; ACUTE LYMPHOBLASTIC-LEUKEMIA; ACUTE MYELOGENOUS LEUKEMIA; DOSE-RATE; ANTI-CD20 ANTIBODY; MYELOID-LEUKEMIA; RANDOMIZED TRIAL AB Delivery of targeted hematopoietic irradiation using radiolabeled monoclonal antibody may improve the outcome of marrow transplantation for advanced acute leukemia by decreasing relapse without increasing toxicity. We conducted a phase 1 study that examined the biodistribution of I-131-labeled anti-CD45 antibody and determined the toxicity of escalating doses of targeted radiation combined with 120 mg/kg cyclophosphamide (CY) and 12 Gy total body irradiation (TBI) followed by HLA-matched related allogeneic or autologous transplant. Forty-four patients with advanced acute leukemia or myelodysplasia received a biodistribution dose of 0.5 mg/kg I-131-BC8 (murine anti-CDQ5) antibody. The mean +/- SEM estimated radiation absorbed dose (centigray per millicurie of I-131) delivered to bone marrow and spleen was 6.5 +/- 0.5 and 13.5 +/- 1.3, respectively, with liver, lung, kidney, and total body receiving lower amounts of 2.8 +/- 0.2, 1.8 +/- 0.1, 0.6 +/- 0.04, and 0.4 +/- 0.02, respectively. Thirty-seven patients (84%) had favorable biodistribution of antibody, with a higher estimated radiation absorbed dose to marrow and spleen than to normal organs. Thirty-four patients received a therapeutic dose of I-131-antibody labeled with 76 to 612 mCi I-131 to deliver estimated radiation absorbed doses to liver (normal organ receiving the highest dose) of 3.5 Gy (level 1) to 12.25 Gy (level 6) in addition to CY and TBI, The maximum tolerated dose was level 5 (delivering 10.5 Gy to liver), with grade III/IV mucositis in 2 of 2 patients treated at level 6. Of 25 treated patients with acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS), 7 survive disease-free 15 to 89 months (median, 65 months) posttransplant. Of 9 treated patients with acute lymphoblastic leukemia (ALL), 3 survive disease-free 19, 54, and 66 months posttransplant. We conclude that I-131-anti-CD45 antibody can safely deliver substantial supplemental doses of radiation to bone marrow (similar to 24 Gy) and spleen (similar to 50 Gy) when combined with conventional CY/TBI. (C) 1999 by The American Society of Hematology. C1 Fred Hutchinson Canc Res Ctr D1 100, Div Clin Res, Seattle, WA 98109 USA. Univ Washington, Dept Pediat, Seattle, WA 98195 USA. Univ Washington, Dept Med, Seattle, WA 98195 USA. Univ Washington, Dept Pediat, Seattle, WA 98195 USA. Pacific NW Natl Lab, Richland, WA USA. RP Matthews, DC (reprint author), Fred Hutchinson Canc Res Ctr D1 100, Div Clin Res, 1100 Fairview Ave N,POB 19024, Seattle, WA 98109 USA. FU NCI NIH HHS [CA44991, CA18029, CA18221] NR 60 TC 192 Z9 203 U1 1 U2 4 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1200 19TH ST, NW, STE 300, WASHINGTON, DC 20036-2422 USA SN 0006-4971 J9 BLOOD JI Blood PD AUG 15 PY 1999 VL 94 IS 4 BP 1237 EP 1247 PG 11 WC Hematology SC Hematology GA 225FE UT WOS:000081947100011 PM 10438711 ER PT J AU Feng, XH Faiia, AM WoldeGabriel, G Aronson, JL Poage, MA Chamberlain, CP AF Feng, XH Faiia, AM WoldeGabriel, G Aronson, JL Poage, MA Chamberlain, CP TI Oxygen isotope studies of illite/smectite and clinoptilolite from Yucca Mountain: implications for paleohydrologic conditions SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE clay minerals; paleohydrology; clinoptilolite; O-18/O-16; Yucca Mountain ID SIERRA-NEVADA; O-ISOTOPE; DIAGENESIS; MINERALOGY; EVOLUTION; SEDIMENTS; ALBERTA; CANADA; BASIN; ROCKS AB Illite/smectite (I/S) and clinoptilolite mineral separates from drill holes in 11 Ma old altered volcanic tuffs of Yucca Mountain, Nevada were analyzed for delta(18)O values. We reconstruct the diagenetic;and paleohydrologic conditions using the isotopic composition of clay minerals combined with other independent geological observations. Our isotopic data show that the delta(18)O values of clay minerals preserve paleohydrologic information from a Middle to Late Miocene episode of hydrothermal alteration at Yucca Mountain. We provide additional evidence for a dual decoupled groundwater circulation system at Yucca Mountain ca. 11 Ma ago. A near-surface system dominated by downward percolation of groundwater is separated from a deeper hydrothermal system by profound thermal and isotopic discontinuities near the R0-R1 I/S transition. Given the set of inferred formation temperatures and the isotopic composition of formation water, we show that the current set of isotopic compositions of clinoptilolite is significantly lower than those at the time of formation, and are not significantly different from the equilibrium values defined by the current groundwater delta(18)O and geothermal gradient. We conclude that, unlike I/S, clinoptilolite has not preserved its original isotopic composition over the past II million years, but we do not know how long is necessary to reset the isotopic signature of clinoptilolite under near-surface conditions. The current groundwater at Yucca Mountain is 4 parts per thousand more enriched in O-18 than the paleogroundwater 10-11 Ma ago as inferred from our reconstruction. This shift may be attributed to a change in the pattern of atmospheric circulation, such as by surficial uplift of the Sierra Nevada, which caused it to become an orographic barrier to moisture penetrating inland from the west. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Dartmouth Coll, Dept Earth Sci, Hanover, NH 03755 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Feng, XH (reprint author), Dartmouth Coll, Dept Earth Sci, Hanover, NH 03755 USA. EM xiahong.feng@dartmouth.edu NR 41 TC 10 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X EI 1385-013X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD AUG 15 PY 1999 VL 171 IS 1 BP 95 EP 106 DI 10.1016/S0012-821X(99)00136-3 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 226FX UT WOS:000082010600008 ER PT J AU Tuang, FN Rademaker, JLW Alocilja, EC Louws, FJ de Bruijn, FJ AF Tuang, FN Rademaker, JLW Alocilja, EC Louws, FJ de Bruijn, FJ TI Identification of bacterial rep-PCR genomic fingerprints using a backpropagation neural network SO FEMS MICROBIOLOGY LETTERS LA English DT Article DE backpropagation neural network; bacterial identification; rep-PCR; genomic fingerprint; Xanthomonas ID XANTHOMONAS; SEQUENCES; CLASSIFICATION; STRAINS AB A backpropagation neural network (BPN) was used to identify bacterial plant pathogens based on their genomic fingerprints. Genomic fingerprint data, comprised of complex DNA band patterns generated using BOX, enterobacterial repetitive intergenic consensus (ERIC) and repetitive extragenic palindromic (REP)-primers (rep-PCR), were used to train three independent BPNs. 10 Strains of the genus Xanthomonas, each with a characteristic host plant range, were identified correctly using the three trained BPNs. When tested with fingerprints of bacterial strains not present in the training sets, the rejection rate was 100%, using the three BPN classifiers combined. Thus, BPN protocols can be employed to generate a powerful computer-based system for the identification of pathogenic bacteria in the genus Xanthomonas. (C) 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved. C1 Michigan State Univ, Dept Agr Engn, E Lansing, MI 48824 USA. Michigan State Univ, MSU DOE Plant Res Lab, E Lansing, MI 48824 USA. Michigan State Univ, NSF Ctr Microbial Ecol, E Lansing, MI 48824 USA. Michigan State Univ, Dept Microbiol, E Lansing, MI 48824 USA. RP Rademaker, JLW (reprint author), Netherlands Culture Collect Bacteria, POB 80056, NL-3508 TB Utrecht, Netherlands. NR 24 TC 9 Z9 9 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1097 J9 FEMS MICROBIOL LETT JI FEMS Microbiol. Lett. PD AUG 15 PY 1999 VL 177 IS 2 BP 249 EP 256 DI 10.1016/S0378-1097(99)00319-5 PG 8 WC Microbiology SC Microbiology GA 225FP UT WOS:000081948000010 ER PT J AU Goldstein, P Dodge, D AF Goldstein, P Dodge, D TI Fast and accurate depth and source mechanism estimation using P-waveform modeling: A tool for special event analysis, event screening, and regional calibration SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOURCE PARAMETERS; EARTHQUAKES AB We have developed, validated, and applied a fast and accurate, interactive, easy to use tool for estimating seismic event depth and mechanism by modeling the initial P-wave bundle. Significant features of this tool include its applicability over a broad band of frequencies (f less than or equal to 2 Hz) and magnitudes (mb greater than or equal to 4.5), its ability to provide accurate high-resolution depth estimates, and its ability to provide constraints on event mechanism including isotropic contributions. It also provides estimates of random and model errors and can be used to lest hypotheses and investigate sensitivity to and trade-offs between model parameters. We Validated this tool and its algorithms by showing that our estimated depths and mechanisms are in excellent agreement with ground-truth depths and mechanisms based on local and regional data. We find that depth can usually be estimated to an accuracy of a few km with a small number of stations. Although complete mechanisms are sometimes poorly resolved, we find that two out of three of the mechanism parameters (strike, dip, rake) are usually well constrained. We illustrate the potential of this technique for regional calibration, special event analysis, and event screening by comparing estimated depths and mechanisms of events in the Middle East and North Africa with those of the National Earthquake Information Center (NEIC) and by comparing our depth and mechanism estimates for the May 11, 1998 India nuclear explosion and a November 8, 1991 earthquake that occurred in the same region. C1 Univ Calif Lawrence Livermore Natl Lab, Geophys & Global Secur Div, Livermore, CA 94550 USA. RP Goldstein, P (reprint author), Univ Calif Lawrence Livermore Natl Lab, Geophys & Global Secur Div, Livermore, CA 94550 USA. NR 13 TC 13 Z9 14 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 1999 VL 26 IS 16 BP 2569 EP 2572 DI 10.1029/1999GL900579 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 226GD UT WOS:000082011200041 ER PT J AU Feldman, WC Skoug, RM Gosling, JT McComas, DJ Tokar, RL Burlaga, LF Ness, NF Smith, CW AF Feldman, WC Skoug, RM Gosling, JT McComas, DJ Tokar, RL Burlaga, LF Ness, NF Smith, CW TI Observations of suprathermal electron conics in an interplanetary coronal mass ejection SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HELIOS PLASMA-EXPERIMENT; SOLAR-WIND ELECTRON; INTER-PLANETARY SHOCK; DISTRIBUTIONS; EVENTS AB Solar wind suprathermal electron velocity distributions measured by the SWEPAM experiment aboard ACE were studied to determine the internal magnetic structure of the coronal mass ejection (CME) that passed 1 AU on 4-5 February, 1998. Pitch-angle distributions range from symmetric counter-streaming to complex distributions that include conics. Identification of suprathermal electron conics in interplanetary CMEs (ICMEs) is reported here for the first time. The origin of these conics is highly uncertain. We suggest, however, that the conics may originate in transient electron heating associated with magnetic reconnection within the magnetic legs of the CMEs. Such reconnection generates large, complex magnetic loops that have enhanced anti-solar electric fields at their solar edge to maintain charge neutrality. This field must be sufficiently strong to bind electrons with high pitch angles to the bottom of the loops as they propagate away from the Sun. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. RP Feldman, WC (reprint author), Univ Calif Los Alamos Natl Lab, MS D466, Los Alamos, NM 87544 USA. NR 16 TC 10 Z9 10 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 1999 VL 26 IS 16 BP 2613 EP 2616 DI 10.1029/1999GL900460 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 226GD UT WOS:000082011200052 ER PT J AU Kwok, DTK Chu, PK Wood, BP Chan, C AF Kwok, DTK Chu, PK Wood, BP Chan, C TI Particle-in-cell and Monte Carlo simulation of the hydrogen plasma immersion ion implantation process SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SILICON-ON-INSULATOR; AUXILIARY ELECTRODE; CYLINDRICAL BORE; BURIED OXIDE; SEPARATION; OXYGEN; FABRICATION; SURFACE AB Hydrogen plasma immersion ion implantation into a 200-mm-diam silicon wafer placed on top of a cylindrical stage has been numerically simulated by the particle-in-cell (PIC) and transport-and-mixing-from-ion-irradiation (TAMIX) methods. The PIC simulation is conducted based on the plasma comprising three hydrogen species H+, H-2(+), and H-3(+) in a ratio determined by secondary ion mass spectrometry. The local sputtering losses and retained doses are calculated by the Monte Carlo code TAMIX. The combined effect of the three species results in a maximum retained dose variation of 11.6% along the radial direction of the wafer, although the implanted dose variation derived by PIC is higher at 21.5%. Our results suggest that the retained dose variations due to off-normal incident ions can partially compensate for variations in incident dose dictated by plasma sheath conditions. The depth profile becomes shallower toward the edge of the wafer. Our results indicate that it is about 34% shallower at the edge, but within a radius of 6.375 cm, the depth of the peak only varies by about 5%. For plasma implantation process design, a combination of PIC and TAMIX is better than the traditional practice of using PIC alone. (C) 1999 American Institute of Physics. [S0021-8979(99)02716-4]. C1 City Univ Hong Kong, Dept Phys & Mat Sci, Kowloon, Peoples R China. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Northeastern Univ, Dept Elect & Comp Engn, Boston, MA 02115 USA. RP Chu, PK (reprint author), City Univ Hong Kong, Dept Phys & Mat Sci, 83 Tat Chee Ave, Kowloon, Peoples R China. EM paul.chu@cityu.edu.hk RI Chu, Paul/B-5923-2013 OI Chu, Paul/0000-0002-5581-4883 NR 29 TC 18 Z9 19 U1 0 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 15 PY 1999 VL 86 IS 4 BP 1817 EP 1821 DI 10.1063/1.370974 PG 5 WC Physics, Applied SC Physics GA 221HD UT WOS:000081720600007 ER PT J AU Hartmann, P Bermuth, J Von Harrach, D Hoffmann, J Kobis, S Reichert, E Aulenbacher, K Schuler, J Steigerwald, M AF Hartmann, P Bermuth, J Von Harrach, D Hoffmann, J Kobis, S Reichert, E Aulenbacher, K Schuler, J Steigerwald, M TI A diffusion model for picosecond electron bunches from negative electron affinity GaAs photocathodes SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID TIME AB Even though theoretical estimates predict response times for the photoemission process of electrons from a negative electron affinity GaAs photoemitter in excess of hundreds of picoseconds, recent measurements found electron bunch durations of 40 ps or less. This work presents precise measurements of picosecond electron bunches from a negative affinity bulk GaAs photocathode and develops a model which explains the measured bunch durations as well as the observed bunch shapes. The bunch shape turns out to be independent from the quantum efficiency of the photoemitter. (C) 1999 American Institute of Physics. [S0021-8979(99)04616-2]. C1 Univ Mainz, Inst Kernphys, D-6500 Mainz, Germany. Univ Mainz, Inst Phys, D-6500 Mainz, Germany. RP Hartmann, P (reprint author), Thomas Jefferson Natl Accelerator Facil, Newport News, VA USA. NR 15 TC 22 Z9 22 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 15 PY 1999 VL 86 IS 4 BP 2245 EP 2249 DI 10.1063/1.371037 PG 5 WC Physics, Applied SC Physics GA 221HD UT WOS:000081720600072 ER PT J AU Shan, W Walukiewicz, W Ager, JW Haller, EE Geisz, JF Friedman, DJ Olson, JM Kurtz, SR AF Shan, W Walukiewicz, W Ager, JW Haller, EE Geisz, JF Friedman, DJ Olson, JM Kurtz, SR TI Effect of nitrogen on the band structure of GaInNAs alloys SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; GAASN; GAP; SEMICONDUCTORS; LUMINESCENCE; GAAS1-XNX AB We show that incorporation of nitrogen in Ga1-xInxAs to form Ga1-xInxNyAs1-y alloys leads to a splitting of the conduction band into two nonparabolic subbands. The splitting can be described in terms of an anticrossing interaction between a narrow band of localized nitrogen states and the extended conduction-band states of the semiconductor matrix. The downward shift of the lower subband edge accounts for the N-induced reduction of the fundamental band-gap energy. An analysis of the relationship between the subband splitting and the band-gap reduction demonstrates that the energetic location of the valence band is nearly independent of the N content in Ga1-xInxNyAs1-y alloys. (C) 1999 American Institute of Physics. [S0021-8979(99)02816-9]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Shan, W (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 25 TC 136 Z9 138 U1 0 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 15 PY 1999 VL 86 IS 4 BP 2349 EP 2351 DI 10.1063/1.371148 PG 3 WC Physics, Applied SC Physics GA 221HD UT WOS:000081720600090 ER PT J AU Rice, MJ Chakraborty, AK Bell, AT AF Rice, MJ Chakraborty, AK Bell, AT TI Al next nearest neighbor, ring occupation, and proximity statistics in ZSM-5 SO JOURNAL OF CATALYSIS LA English DT Article ID BRONSTED ACIDITY; H-ZSM-5; DENSITY; CATIONS AB The distribution of framework Al in ZSM-5 was simulated for various Si/Al ratios and the results used to determine the fraction of Al atoms in next nearest neighbors (NNN)T sites. All the 4-, 5-, and 6-membered rings were identified in the unit cell and the fraction of these rings with 0, 1, 2, and 3 Al was calculated. Lastly, the radial distribution function of A-Al pairs, the number of Al's expected within a sphere of radius, r, centered around an Al (E), and the probability of finding at least one Al within a sphere of radius, r, centered around an Al (P) were calculated for different Si/Al ratios. Based on these results, the probability of locating NNN pairs of Al atoms situated at a distance suitable for the stabilization of M2+ and [M-O-M](2+) cations were carried out and then used to determine maximum values for M2+/Al and [M-O-M](2+)/Al. The value of M2+/Al is 0.12 for Si/Al = 12 and 0.07 for Si/Al = 24, and the value of [M-O-M](2+) is 0.30 for Si/Al = 12 and 0.19 for Si/Al = 24. The values of M2+/Al obtained theoretically are in reasonable agreement with those observed experimentally for Pd-ZSM-5. A significant finding of our simulation is that Lowenstein's rule is the dominant factor governing short-range correlations of framework Al atoms, and hence the distribution of NNN pairs of Al atoms. As a consequence, analytical theories that include consideration of Lowenstein's rule provide rather accurate estimates of the probability of finding Al NNN pairs. (C) 1999 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Div Mat Sci, Berkeley, CA 94720 USA. RP Bell, AT (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem Engn, Berkeley, CA 94720 USA. OI Bell, Alexis/0000-0002-5738-4645 NR 7 TC 74 Z9 74 U1 1 U2 12 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9517 J9 J CATAL JI J. Catal. PD AUG 15 PY 1999 VL 186 IS 1 BP 222 EP 227 DI 10.1006/jcat.1999.2544 PG 6 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA 230KN UT WOS:000082250500023 ER PT J AU Atchity, GJ Ruedenberg, K AF Atchity, GJ Ruedenberg, K TI Orbital transformations and configurational transformations of electronic wavefunctions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SPACE SCF METHOD; NONORTHOGONAL ORBITALS; MOLECULAR-INTERACTIONS; BIORTHOGONAL ORBITALS; WAVE-FUNCTIONS; PERTURBATION; MOMENTS; STATE AB Transformations among molecular orbitals are often expedient or illuminating, and sometimes essential in quantum chemical contexts. In order to express the many-electron wavefunction in terms of the corresponding transformed configurations, full CI calculations used to be repeated in the transformed orbital basis. The configurational transformations can however be obtained directly, as shown by Malmqvist, by a factorization into single orbital transformations. In the present paper, a direct transformation method is presented that is based on the factorization of orbital transformations in terms of Jacobi rotations. Compared to the repetition of a CI calculation, both direct re-expansion methods drastically reduce the computational effort and increase the numerical accuracy. They are, moreover, applicable to wavefunctions whose original construction is not accessible. (C) 1999 American Institute of Physics. [S0021-9606(99)00621-2]. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Atchity, GJ (reprint author), 11705 Mackey St, Overland Pk, KS 66210 USA. NR 41 TC 9 Z9 9 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 15 PY 1999 VL 111 IS 7 BP 2910 EP 2920 DI 10.1063/1.479573 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 222GB UT WOS:000081774700009 ER PT J AU Zanni, MT Greenblatt, BJ Davis, AV Neumark, DM AF Zanni, MT Greenblatt, BJ Davis, AV Neumark, DM TI Photodissociation of gas phase I-3(-) using femtosecond photoelectron spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID STIMULATED RAMAN-SCATTERING; VIBRATIONAL-RELAXATION; SYMMETRY-BREAKING; TRIIODIDE ION; ULTRAFAST PHOTODISSOCIATION; GEMINATE RECOMBINATION; IMPULSIVE EXCITATION; ABSORPTION-SPECTRA; TRANSITION-STATE; TRIHALIDE IONS AB The photodissociation dynamics of gas phase I-3(-) following 390 nm excitation are studied using femtosecond photoelectron spectroscopy. Both I- and I-2(-) photofragments are observed; the I-2(-) exhibits coherent oscillations with a period of 550 fs corresponding to similar to 0.70 eV of vibrational excitation. The oscillations dephase by 4 ps and rephase at 45 and 90.5 ps on the anharmonic I-2(-) potential. The gas phase frequency of ground state I-3(-) is determined from oscillations in the photoelectron spectrum induced by resonance impulsive stimulated Raman scattering. The dynamics of this reaction are modeled using one- and two-dimensional wave packet simulations from which we attribute the formation of I- to three-body dissociation along the symmetric stretching coordinate of the excited anion potential. The photodissociation dynamics of gas phase I-3(-) differ considerably from those observed previously in solution both in terms of the I-2(-) vibrational distribution and the production of I-. (C) 1999 American Institute of Physics. [S0021-9606(99)01930-3]. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Zanni, MT (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Zanni, Martin/K-2707-2013; Neumark, Daniel/B-9551-2009 OI Neumark, Daniel/0000-0002-3762-9473 NR 64 TC 39 Z9 39 U1 0 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 15 PY 1999 VL 111 IS 7 BP 2991 EP 3003 DI 10.1063/1.479660 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 222GB UT WOS:000081774700019 ER PT J AU Skurski, P Gutowski, M AF Skurski, P Gutowski, M TI Ab initio study of the dipole-bound anion (H2O...HCl)(-) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HYDRATED ELECTRON CLUSTERS; FRANCK-CONDON PRINCIPLE; PHOTOELECTRON-SPECTROSCOPY; MOLECULAR-COMPLEXES; GROUND-STATE; VIBRONIC TRANSITIONS; POLYATOMIC-MOLECULES; DYNAMICAL SYMMETRY; WATER DIMER; BASIS-SETS AB The (H2O...HCl)(-) anion has been studied at the coupled cluster level of theory with single, double, and noniterative, triple excitations whereas lowest energy structures have been determined at the second-order Moller-Plesset level. The vertical electron detachment energy and the adiabatic electron affinity were found to be 475 and 447 cm(-1), respectively, and they agree very well with the maximum of the dominant peak in the photoelectron spectrum of (H2O...HCl)(-) at 436 cm(-1), recorded by Bowen and collaborators. Our results indicate that electron correlation contributions to the electron binding energy are important and represent similar to 70% of its total value. Both for the neutral and the anion, the two equivalent C-s symmetry minima are separated by a C-2v transition state and the energy barrier amounts to only 77 cm(-1). Thus the equilibrium structures averaged over vibrations are effectively planar (C-2v). The Franck-Condon (FC) factors, calculated in harmonic approximation, indicate that the neutral complex formed in photoelectron spectroscopy (PES) experiments may be vibrationally excited in both soft intermolecular and stiff intramolecular modes. The theoretical photoelectron spectrum based on the calculated FC factors is compared to the experimental PES spectrum of Bowen (C) 1999 American Institute of Physics. [S0021-9606(99)30331-7]. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA. Univ Gdansk, Dept Chem, PL-80952 Gdansk, Poland. RP Gutowski, M (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 58 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 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 15 PY 1999 VL 111 IS 7 BP 3004 EP 3011 DI 10.1063/1.479614 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 222GB UT WOS:000081774700020 ER PT J AU Jarvis, GK Evans, M Ng, CY Mitsuke, K AF Jarvis, GK Evans, M Ng, CY Mitsuke, K TI Rotational-resolved pulsed field ionization photoelectron study of NO+(X-1 Sigma(+),v(+)=0-32) in the energy range of 9.24-16.80 eV SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SYNCHROTRON-RADIATION; NITRIC-OXIDE; SPECTROSCOPY; THRESHOLD; PHOTOIONIZATION; NO; O-2; TRANSITION; SPECTRUM; STATES AB We have obtained rotationally resolved pulsed filed ionization photoelectron (PFI-PE) spectra of NO in the energy range of 9.2-16.8 eV, covering ionization transitions of NO+(X (1)Sigma(+),v(+)=0-32,J(+))<-- NO(X (2)Pi(3/2,1/2),v"=0,J"). The PFI-PE bands for NO+(X (1)Sigma(+),v(+)=6-32) obtained here represent the first rotationally resolved spectroscopic data for these states. The simulation using the Buckingham-Orr-Sichel model provides accurate molecular constants for NO+(X (1)Sigma(+),v(+)=0-32), including ionization energies, vibrational constants (omega(e)(+)=2 382.997 +/- 0.122 cm(-1), omega(e)(+)chi(e)(+)=17.437 84 +/- 0.000 90 cm(-1), omega(e)(+)y(e)(+)=0.063 209 5 +/- 3.2x10(-6) cm(-1), and omega(e)(+)z(e)(+)=-0.001 400 0 +/- 7.2x10(-8) cm(-1)), and rotational constants (B-e(+)=1.996 608 +/- 0.006 259 cm(-1), alpha(e)(+)=0.020 103 +/- 6.3x10(-5) cm(-1), and gamma(e)(+)=-(7.22 +/- 2.26)x10(-6) cm(-1)). For v(+)=0-15, the rotational branches are Delta J=J(+)-J"=+/- 1/2, +/- 3/2, +/- 5/2, +/- 7/2, and +/- 9/2, which correspond to the formation of photoelectron angular momentum states l=0, 1, 2, and 3. The Delta J=+/- 1/2, +/- 3/2, +/- 5/2, +/- 7/2, +/- 9/2, and +/- 11/2 rotational branches are observed in the spectra for v(+)=16-32, revealing the production of continuum photoelectron states l=0, 1, 2, 3, and 4. The maximum Delta J value and intensities for high Delta J rotational branches are found to generally increase as v(+) is increased in the range of 0-32. This observation is attributed to an increase in inelastic cross sections for collisions between the outgoing photoelectron and the nonspherical molecular ion core as the bond distance for NO+ is increased. Thus, this observation can be taken as strong support for the electron-molecular-ion-core scattering model for angular momentum and energy exchanges in the threshold photoionization of NO. (C) 1999 American Institute of Physics. [S0021-9606(99)00930-7]. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Inst Mol Sci, Okazaki, Aichi 4448585, Japan. RP Jarvis, GK (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. NR 49 TC 45 Z9 45 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 15 PY 1999 VL 111 IS 7 BP 3058 EP 3069 DI 10.1063/1.479586 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 222GB UT WOS:000081774700027 ER PT J AU Sohlberg, K Yarkony, DR AF Sohlberg, K Yarkony, DR TI On the strongly bound B (3)Pi state of the CAr van der Waals complex: Bonding and predissociation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRONICALLY NONADIABATIC INTERACTIONS; LARGE ENERGY SHIFTS; FLUORESCENCE EXCITATION; RADIATIONLESS DECAY; BAR; SPECTROSCOPY; C-2-DELTA; MOLECULES; ASYMPTOTE; NARROW AB For the open shell van der Waals molecule, CAr, the potential energy curves (PECs) for the B (3)Pi and 1 (5)Sigma(-) states, the B (3)Pi-1 (5)Sigma(-) spin-orbit coupling and the B (3)Pi fine structure splitting are determined using multireference configuration interaction wave functions as large as similar to 8 million configuration state functions. The B (3)Pi state is strongly bound, with D-e=5100 cm(-1). R-e(B (3)Pi)=3.7a(0) and is considerably shorter than R-e(X (3)Sigma(-))=6.07 a(0). The PEC for the repulsive 1 (5)Sigma(-) state crosses that of the B (3)Pi state at R-x(1 (5)Sigma(-),B (3)Pi)=3.31a(0) leading to spin-orbit induced predissociation. The B (3)Pi-1 (5)Sigma(-) spin-orbit coupling is the result of valence-Ryberg mixing in the B (3)Pi state and is considerably enhanced by the heavy atom effect. The heavy atom effect is also reflected in a marked decrease in the fine structure splitting of the B (3)Pi state with increasing vibrational level. The implications of these results for using CAr(B (3)Pi) in laser induced fluorescence detection of CAr(X (3)Sigma(-),v) are discussed. (C) 1999 American Institute of Physics. [S0021-9606(99)30530-4]. C1 Johns Hopkins Univ, Dept Chem, Baltimore, MD 21218 USA. RP Sohlberg, K (reprint author), Oak Ridge Natl Lab, 3025N MS6031, Oak Ridge, TN 37831 USA. NR 25 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 15 PY 1999 VL 111 IS 7 BP 3070 EP 3076 DI 10.1063/1.479587 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 222GB UT WOS:000081774700028 ER PT J AU Blank, DA Kaufman, LJ Fleming, GR AF Blank, DA Kaufman, LJ Fleming, GR TI Fifth-order two-dimensional Raman spectra of CS2 are dominated by third-order cascades SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FEMTOSECOND 2-DIMENSIONAL SPECTROSCOPY; 5TH-ORDER NONLINEAR SPECTROSCOPY; TIME-RESOLVED 4-WAVE; LIQUID CS2; VIBRATIONAL SPECTROSCOPY; CONDENSED-PHASE; MODES; SCATTERING; PULSES; MECHANISMS AB We have demonstrated that fifth-order stimulated Raman spectra of the intermolecular modes in CS2 are dominated by cascading third-order processes. Previous studies have successfully discriminated against a sequential cascading process, but did not account for parallel third-order cascades. All of our measured spectra were successfully simulated considering only cascades built directly from our measured third-order spectra. Using an appropriately chosen phase matching geometry we also measured the sequential cascade, which should exist with equal probability to the parallel cascade. When employing a phase matching geometry that provided substantial discrimination against all of the third-order cascades we were not able to measure any signal. We assign an upper limit for the true fifth-order signal of 2% of the cascaded signal. (C) 1999 American Institute of Physics. [S0021-9606(99)00131-2]. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Blank, DA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 50 TC 162 Z9 162 U1 1 U2 17 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 15 PY 1999 VL 111 IS 7 BP 3105 EP 3114 DI 10.1063/1.479591 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 222GB UT WOS:000081774700032 ER PT J AU Halley, JW Duan, Y Curtiss, LA Baboul, AG AF Halley, JW Duan, Y Curtiss, LA Baboul, AG TI Lithium perchlorate ion pairing in a model of amorphous polyethylene oxide SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID X-RAY-ABSORPTION; MOLECULAR-DYNAMICS MODEL; CONDUCTIVITY; COMPLEXES; LIQUID; SALT AB We report a molecular dynamics study of pairing and dynamics of lithium cation and perchlorate anion in a previously reported model of amorphous polyethylene oxide. We are particularly interested in the question of whether these ions pair in the model, as previously reported experimentally. We calculate the potential of mean force between a lithium and perchlorate ion in the system for several temperatures when a pair of ions is at various separation distances in our model. We find evidence for two minima in the potential of mean force, one at lithium-chlorine separations of 3.5 Angstrom and about 6.5 Angstrom. We studied the same system with five ion pairs in the system and again find two minima at the same separation distances but in this case there is evidence of entropic effects in the binding free energy of the pairs at 3.5 Angstrom. A study of radial distribution functions permits us to deduce information concerning the structure of the paired states. (C) 1999 American Institute of Physics. [S0021-9606(99)50929-X]. C1 Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Halley, JW (reprint author), Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. NR 13 TC 27 Z9 27 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 15 PY 1999 VL 111 IS 7 BP 3302 EP 3308 DI 10.1063/1.479609 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 222GB UT WOS:000081774700054 ER PT J AU Kupferman, R Denn, MM AF Kupferman, R Denn, MM TI Simulation of the evolution of concentrated shear layers in a Maxwell fluid with a fast high-resolution finite-difference scheme SO JOURNAL OF NON-NEWTONIAN FLUID MECHANICS LA English DT Article DE Maxwell; resolution; covergence; shear layers; stress ID HYPERBOLIC CONSERVATION-LAWS AB We employ a new second-order extension of the Lax-Friedrichs scheme, with incompressibility imposed by means of a projection algorithm, to follow the evolution of the vorticity and stress fields for a Maxwell fluid in a two-dimensional periodic system initialized with two thin and concentrated shear layers. The scheme is simple, efficient, and robust, and is capable, in particular, of resolving large stress gradients. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Math, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. RP Kupferman, R (reprint author), Hebrew Univ Jerusalem, Inst Math, IL-91904 Jerusalem, Israel. NR 15 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0257 J9 J NON-NEWTON FLUID JI J. Non-Newton. Fluid Mech. PD AUG 15 PY 1999 VL 84 IS 2-3 BP 275 EP 287 DI 10.1016/S0377-0257(98)00157-8 PG 13 WC Mechanics SC Mechanics GA 207WN UT WOS:000080958900010 ER PT J AU Di Lorenzo, ML Zhang, G Pyda, M Lebedev, BV Wunderlich, B AF Di Lorenzo, ML Zhang, G Pyda, M Lebedev, BV Wunderlich, B TI Heat capacity of solid-state biopolymers by thermal analysis SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE heat capacity; solid proteins; vibrational spectrum; addition scheme; poly(amino acid) ID CARBON BACKBONE POLYMERS; LINEAR MACROMOLECULES; THERMODYNAMIC PROPERTIES; POLY(AMINO ACID)S; GLOBULAR-PROTEINS; GLASS-TRANSITION; DENATURATION; COLLAGEN AB Heat capacities in the solid state of four globular proteins (bovine beta-lactoglobulin, chicken lysozyme, ovalbumine, and horse myoglobin) and of the poly(amino acid) poly(L-tryptophan) have been determined using the Advanced THermal Analysis System (ATHAS). The experimental measurements were performed with adiabatic and differential scanning calorimetry over wide temperature ranges. The heat capacities were linked to an approximate vibrational spectrum by making use of known group vibrations and of a set of parameters, Theta(1) and Theta(3), of the Tarasov function for the skeletal vibrations. Good agreement was found between experiments and calculations with root mean square errors mostly within +/-3%. The experimental data were analyzed also with an empirical addition scheme using the known data for poly(amino acid)s measured earlier. Based on this study, vibrational heat capacities can now be predicted for all proteins with an accuracy comparable to common experiments. (C) 1999 John Wiley & Sons, Inc. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Nizhnii Novgorod, Inst Chem, Nizhnii Novgorod 603600, Russia. RP Wunderlich, B (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. RI Di Lorenzo, Maria Laura/N-5692-2015 NR 40 TC 18 Z9 18 U1 0 U2 11 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD AUG 15 PY 1999 VL 37 IS 16 BP 2093 EP 2102 DI 10.1002/(SICI)1099-0488(19990815)37:16<2093::AID-POLB12>3.3.CO;2-U PG 10 WC Polymer Science SC Polymer Science GA 221HM UT WOS:000081721700012 ER PT J AU Nolan, DS Farrell, BF AF Nolan, DS Farrell, BF TI The structure and dynamics of tornado-like vortices SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID 2ND-ORDER PROJECTION METHOD; NUMERICAL-SIMULATION; BOUNDARY-LAYER; VORTEX; STORM AB The structure and dynamics of axisymmetric tornado-like vortices are explored with a numerical model of axisymmetric incompressible flow based on recently developed numerical methods. The model is first shown to compare favorably with previous results and is then used to study the effects of varying the major parameters controlling the vortex: the strength of the convective forcing, the strength of the rotational Forcing, and the magnitude of the model eddy viscosity. Dimensional analysis of the model problem indicates that the results must depend on only two dimensionless parameters. The natural choices for these two parameters are a convective Reynolds number (based on the velocity scale associated with the convective forcing) and a parameter analogous to the swirl ratio in laboratory models. However, by examining sets of simulations with different model parameters it is found that a dimensionless parameter known as the vortex Reynolds number, which is the ratio of the farfield circulation to the eddy viscosity, is more effective than the conventional swirl ratio for predicting the structure of the vortex. As the value of the vortex Reynolds number is increased, it is observed that the tornado-like vortex transitions from a smooth, steady flow to one with quasiperiodic oscillations. These oscillations, when present, are caused by axisymmetric disturbances propagating down toward the surface from the upper part of the domain, Attempts to identify these oscillations with linear waves associated with the shears of the mean azimuthal and vertical winds give mixed results. The parameter space defined by the choices for model parameters is further explored with large sets of numerical simulations. For much of this parameter space it is confirmed that the vortex structure and time-dependent behavior depend strongly on the vortex Reynolds number and only weakly on the convective Reynolds number. The authors also find that for higher convective Reynolds numbers, the maximum possible wind speed increases, and the rotational forcing necessary to achieve that wind speed decreases. Physical reasoning is used to explain this behavior, and implications for tornado dynamics are discussed. C1 Lawrence Berkeley Lab, Dept Math, Berkeley, CA USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. RP Nolan, DS (reprint author), Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. NR 41 TC 39 Z9 39 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD AUG 15 PY 1999 VL 56 IS 16 BP 2908 EP 2936 DI 10.1175/1520-0469(1999)056<2908:TSADOT>2.0.CO;2 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 230DW UT WOS:000082237400010 ER PT J AU Hsueh, CH Fuller, ER Langer, SA Carter, WC AF Hsueh, CH Fuller, ER Langer, SA Carter, WC TI Analytical and numerical analyses for two-dimensional stress transfer SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE stress transfer; interface; composite; analytical modeling; numerical simulations ID FIBER PULL-OUT; CERAMIC COMPOSITES; ELLIPSOIDAL INCLUSIONS; MATRIX COMPOSITES; STRENGTH; FRACTURE AB Both analytical modeling and numerical simulations were performed to analyze the stress transfer in platelet-reinforced composites in a two-dimensional sense. In the two-dimensional model, an embedded elongated plate bonded to a matrix along its long edges was considered. The system was subjected to both tensile loading parallel to the plate's long edges and residual thermal stresses. The ends of the plate can be debonded from or bonded to the matrix during loading, and both cases were considered in the analysis. Good agreement was obtained between the present analytical and numerical solutions. However, better agreement between analytical and numerical models was obtained for the case of bonded ends than for debonded ends. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Hsueh, CH (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Hsueh, Chun-Hway/G-1345-2011; Carter, W/K-2406-2012 NR 24 TC 30 Z9 31 U1 1 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD AUG 15 PY 1999 VL 268 IS 1-2 BP 1 EP 7 DI 10.1016/S0921-5093(99)00129-X PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 211FK UT WOS:000081149700001 ER PT J AU Lee, S Liaw, PK Liu, CT Chou, YT AF Lee, S Liaw, PK Liu, CT Chou, YT TI Cracking in Cr-Cr2Nb eutectic alloys due to thermal stresses SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE thermal stress; eutectic network; Cr-rich matrix; Cr2NB matrix; microcracks ID INTERMETALLIC COMPOUNDS; MICROSTRUCTURE AB The microstructures of the Cr- Cr2Nb two-phase alloy as affected by thermal stresses have been investigated for three different systems: (1) Cr-rich particles surrounded by the eutectic network; (7) Cr2Nb particles embedded in the Cr-rich matrix, and (3) Cr-rich particles inside the Cr2Nb matrix. Micrographs of the as-cast and annealed specimens show that microcracks are primarily located at the interface between the particle and the matrix. These observations are related to the presence of thermal stress held of elastic inclusions with its maximum tensile and shear stresses located st the interface boundary. The theoretical analyses presented support the formation of crack embryos at the interface as the local tensile stress exceeds the critical value for crack nucleation, (C) 1999 Elsevier Science S.A. All rights reserved. C1 Natl Tsing Hua Univ, Dept Mat Sci, Hsinchu, Taiwan. Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Lee, S (reprint author), Natl Tsing Hua Univ, Dept Mat Sci, Hsinchu, Taiwan. EM sblee@mse.ntu.edu.tw OI Liu, Chain Tsuan/0000-0001-7888-9725 NR 23 TC 25 Z9 35 U1 1 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD AUG 15 PY 1999 VL 268 IS 1-2 BP 184 EP 192 DI 10.1016/S0921-5093(99)00068-4 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 211FK UT WOS:000081149700022 ER PT J AU Raymond, TD Alford, WJ Crawford, MH Allerman, AA AF Raymond, TD Alford, WJ Crawford, MH Allerman, AA TI Intracavity frequency doubling of a diode-pumped external-cavity surface-emitting semiconductor laser SO OPTICS LETTERS LA English DT Article ID BLUE-LIGHT GENERATION AB We present a compact, robust, solid-state blue-light (490-nm) source capable of greater than 5 mW of output in a TEM00 mode. This device is an optically pumped, vertical external-cavity surface-emitting laser with an intracavity frequency-doubling crystal. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Raymond, TD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 9 TC 76 Z9 78 U1 0 U2 9 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD AUG 15 PY 1999 VL 24 IS 16 BP 1127 EP 1129 DI 10.1364/OL.24.001127 PG 3 WC Optics SC Optics GA 227JB UT WOS:000082076400015 PM 18073961 ER PT J AU Relle, S Grant, SB Tsouris, C AF Relle, S Grant, SB Tsouris, C TI Diffusional coagulation of superparamagnetic particles in the presence of an external magnetic field SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS LA English DT Article DE diffusion limited coagulation; colloidal magnetic particle coagulation; dynamic scaling; cluster size distributions; superparamagnetic particles; single cluster detection ID COLLOIDAL AGGREGATION; MICROSPHERES; FLOCCULATION; KINETICS AB In this paper, we investigate the diffusional coagulation of colloidal superparamagnetic (SP) latex particles that are under the influence of an external magnetic field. The cluster size distributions (CSDs) that evolve with time were determined using an optical set-up that permits the direct visualization of particle clusters. Following the dynamic scaling analysis of van Dongen and Ernst (Phys. Rev. Lett. 54 (1985) 1396), we find that the CSDs all collapse onto a master curve when properly scaled. The bell-shape of this master curve indicates that lame clusters preferentially scavenge small clusters in our system. From the time evolution of the average cluster size we infer that the reactivity between large clusters diminishes with increasing cluster size. These results are consistent with a simple mathematical formulation of the coagulation rate constant, or kernel, for the Brownian coagulation of magnetic particles. Moreover, our results support a growing body of evidence that the dynamic scaling theory developed by van Dongen and Ernst is a useful framework with which to study the microscale processes governing particle coagulation. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Grant, SB (reprint author), Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA. EM sbgrant@uci.edu RI Tsouris, Costas/C-2544-2016; Grant, Stanley/K-8179-2016 OI Tsouris, Costas/0000-0002-0522-1027; Grant, Stanley/0000-0001-6221-7211 NR 29 TC 8 Z9 8 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD AUG 15 PY 1999 VL 270 IS 3-4 BP 427 EP 443 DI 10.1016/S0378-4371(99)00100-4 PG 17 WC Physics, Multidisciplinary SC Physics GA 232NA UT WOS:000082375800007 ER PT J AU Sigalas, MM Biswas, R Ho, KM Soukoulis, CM Crouch, DD AF Sigalas, MM Biswas, R Ho, KM Soukoulis, CM Crouch, DD TI Waveguides in three-dimensional metallic photonic band-gap materials SO PHYSICAL REVIEW B LA English DT Article ID STOP BANDS; CRYSTALS AB We theoretically investigate waveguide structures in three-dimensional metallic photonic band-gap (MPBG) materials. The MPBG materials used in this study consist of a three-dimensional mesh of metallic wires embedded in a dielectric. An L-shaped waveguide is created by removing part of the metallic wires. Using finite difference time domain simulations, we found that an 85% transmission efficiency can be achieved through the 90 degrees bend with just three unit cell thickness MPBG structures. [S0163-1829(99)13831-1]. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Raytheon Corp, Adv Electromagnet Technol Ctr, Rancho Cucamonga, CA 91729 USA. RP Sigalas, MM (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Soukoulis, Costas/A-5295-2008 NR 18 TC 45 Z9 45 U1 0 U2 2 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 AUG 15 PY 1999 VL 60 IS 7 BP 4426 EP 4429 DI 10.1103/PhysRevB.60.4426 PG 4 WC Physics, Condensed Matter SC Physics GA 230FQ UT WOS:000082241500009 ER PT J AU Jones, ED Modine, NA Allerman, AA Kurtz, SR Wright, AF Tozer, ST Wei, X AF Jones, ED Modine, NA Allerman, AA Kurtz, SR Wright, AF Tozer, ST Wei, X TI Band structure of InxGa1-xAs1-yNy alloys and effects of pressure SO PHYSICAL REVIEW B LA English DT Article ID WAVELENGTH SEMICONDUCTOR-LASERS; TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; MOLECULAR-DYNAMICS; OPTICAL-PROPERTIES; GAASN ALLOYS; GAINNAS; GAP; LUMINESCENCE; PERFORMANCE AB InxGa1-xAs1-yNy is a semiconductor alloy system with the remarkable property that the inclusion of only 2% nitrogen reduces the band gap by more than 30%. In order to help understand the physical origin of this extreme deviation from the typically observed nearly linear dependence of alloy properties on concentration, we have investigated the pressure dependence of the excited state energies using both experimental and theoretical methods. We report measurements of the low-temperature photoluminescence of the material for pressures between ambient and 110 kbar. We also describe a density-functional-theory-based approach to calculating the pressure dependence of low lying excitation energies for low-concentration alloys. The theoretically predicted pressure dependence of the band gap is in excellent agreement with the experimental data. Based on the results of our calculations, we suggest an explanation for the strongly nonlinear pressure dependence of the band gap that, surprisingly, does not involve a nitrogen impurity band. [S0163-1829(99)03731-5]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Natl High Magnet Field Lab, Tallahassee, FL USA. RP Jones, ED (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 31 TC 182 Z9 185 U1 2 U2 13 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 AUG 15 PY 1999 VL 60 IS 7 BP 4430 EP 4433 DI 10.1103/PhysRevB.60.4430 PG 4 WC Physics, Condensed Matter SC Physics GA 230FQ UT WOS:000082241500010 ER PT J AU Zhang, SB AF Zhang, SB TI Defect metastability in surfaces: A study of EL2 defect in GaAs(110) SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; ARSENIC ANTISITE DEFECTS; GAAS; BULK AB Although it has been widely accepted that EL2 in GaAs is an As antisite, the identity of the metastable state of EL2 (=EL2*) has not been confirmed by experiment. Here it is suggested that cross-sectional scanning tunneling microscopy may be used to identify EL2*. My suggestion is based on a comprehensive first-principles total energy study of surface defect metastability. It reveals rich structures of the EL2* near the surface. The energy difference between EL2* and EL2 can be reduced to only a tenth of that bulk due to interaction with relaxed surface atoms. [S0163-1829(99)11127-5]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Zhang, SB (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Krausnick, Jennifer/D-6291-2013; Zhang, Shengbai/D-4885-2013 OI Zhang, Shengbai/0000-0003-0833-5860 NR 15 TC 6 Z9 6 U1 0 U2 2 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 AUG 15 PY 1999 VL 60 IS 7 BP 4462 EP 4465 DI 10.1103/PhysRevB.60.4462 PG 4 WC Physics, Condensed Matter SC Physics GA 230FQ UT WOS:000082241500018 ER PT J AU Zhang, XG Nicholson, DMC AF Zhang, XG Nicholson, DMC TI Generalized local-density approximation for spherical potentials SO PHYSICAL REVIEW B LA English DT Article ID ENERGY AB An alternative density functional for the spherical approximation of cell potentials is formulated. It relies on overlapping atomic spheres for the calculation of the kinetic energy, similar to the atomic sphere approximation (ASA), however, a shape correction is used that has the same form as the interstitial treatment in the nonoverlapping muffin-tin (MT) approach. The intersite Coulomb energy is evaluated using the Madelung energy as computed in the MT approach, while the on-site Coulomb energy is calculated using the ASA. The Kohn-Sham equations for the functional are then solved self-consistently. The ASA is known to give poor elastic constants and good point defect energies. Conversely the MT approach gives good elastic constants and poor point defect energies. The proposed new functional maintains the simplicity of the spherical potentials found in the ASA and MT approaches, but gives good values for both elastic constants and point defects. This solution avoids a problem, absent in the ASA but suffered by the MT approximation, of incorrect distribution of site charges when charge transfer is large. Relaxation of atomic positions is thus facilitated. Calculations confirm that the approach gives similar elastic constants to the MT approximation, and defect formation energies similar to those obtained with ASA. [S0163-1829(99)09631-9]. C1 Oak Ridge Natl Lab, Computat Phys & Engn Div, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Computat Phys & Engn Div, POB 2008, Oak Ridge, TN 37831 USA. NR 14 TC 15 Z9 15 U1 0 U2 1 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 AUG 15 PY 1999 VL 60 IS 7 BP 4551 EP 4557 DI 10.1103/PhysRevB.60.4551 PG 7 WC Physics, Condensed Matter SC Physics GA 230FQ UT WOS:000082241500040 ER PT J AU Tyson, TA Qian, Q Kao, CC Rueff, JP de Groot, FMF Croft, M Cheong, SW Greenblatt, M Subramanian, MA AF Tyson, TA Qian, Q Kao, CC Rueff, JP de Groot, FMF Croft, M Cheong, SW Greenblatt, M Subramanian, MA TI Valence state of Mn in Ca-doped LaMnO3 studied by high-resolution Mn K-beta emission spectroscopy SO PHYSICAL REVIEW B LA English DT Article ID X-RAY-ABSORPTION; GIANT MAGNETORESISTANCE; COLOSSAL MAGNETORESISTANCE; LA1-XCAXMNO3; LA1-XSRXMNO3; TRANSITION; TEMPERATURE; SYSTEM; OXIDE; FILMS AB Mn K-beta x-ray emission spectra provide a direct method to probe the effective spin state and charge density on the Mn atom and is used in an experimental study of a class of Mn oxides. Specifically, the Mn K-beta line positions and detailed spectral shapes depend on the oxidation and the spin state of the Mn sites as well as the degree of d covalency/itinerancy. Theoretical calculations including atomic charge and multiplet effects, as well as crystal-field splittings and covalency effects, are used as a guide to the experimental results. Direct comparison of the ionic system MnF2 and the covalent system MnO reveals significant changes due to the degree of covalency of Mn within atomic-type Mn K-beta simulations. Moreover, comparisons of measurement with calculations support the assumed high spin state of Mn in all of the systems studied. The detailed shape and energy shift of the spectra for the perovskite compounds, LaMnO3 and CaMnO3, are, respectively, found to be very similar to the covalent Mn3+-Mn2O3 and Mn4+-MnO2 compounds thereby supporting the identical Mn-state assignments. Comparison to the theoretical modeling emphasizes the strong covalency in these materials. Detailed Mn K-beta x-ray emission results on the La1-xCaxMnO3 system can be well fit by linear superpositions of the end member spectra, consistent with a mixed-valent character for the intermediate compositions. However, an arrested Mn-valence response to the doping in the x<0.3 range is found. No evidence for Mn2+ is observed at any x values seemingly ruling out proposals regarding Mn3+ disproportionation. [S0163-1829(99)02231-6]. C1 New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Groningen, Ctr Mat Sci, NL-9747 AG Groningen, Netherlands. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Rutgers State Univ, Dept Chem, Piscataway, NJ 08854 USA. DuPont Co Inc, Cent Res & Dev, Wilmington, DE 19880 USA. RP New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. RI de Groot, Frank/A-1918-2009; Rueff, Jean-Pascal/D-8938-2016 OI Rueff, Jean-Pascal/0000-0003-3594-918X NR 46 TC 52 Z9 53 U1 2 U2 8 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 AUG 15 PY 1999 VL 60 IS 7 BP 4665 EP 4674 DI 10.1103/PhysRevB.60.4665 PG 10 WC Physics, Condensed Matter SC Physics GA 230FQ UT WOS:000082241500055 ER PT J AU Kner, P Bar-Ad, S Marquezini, MV Chemla, DS Lovenich, R Schafer, W AF Kner, P Bar-Ad, S Marquezini, MV Chemla, DS Lovenich, R Schafer, W TI Effect of magnetoexciton correlations on the coherent emission of semiconductors SO PHYSICAL REVIEW B LA English DT Article ID GAAS QUANTUM-WELLS; NONLINEAR-OPTICAL-RESPONSE; EXCITON-EXCITON CORRELATIONS; FREE-INDUCTION DECAY; POLARIZATION DEPENDENCE; 4-WAVE-MIXING SIGNALS; MAGNETIC-FIELD; 2-DIMENSIONAL MAGNETOEXCITONS; CONTINUUM STATES; BLOCH EQUATIONS AB Mean-field, Hartree-Fock theory has been successful in explaining many nonlinear optical experiments in semiconductors. But recently experiments have shown important cases where the mean-field theory (the semiconductor Bloch equations) fails. One such case is bulk GaAs in a strong magnetic field. Here the exciton-exciton interaction can be tuned by varying the magnetic field, providing an excellent method for studying the transition from a regime where mean-field theory is valid to a regime where exciton-exciton correlations must be taken into account. We perform ultrafast time-resolved four-wave mixing on bulk GaAs in a magnetic field, and compare our experimental results with theoretical calculations which go beyond Hartree-Fock theory. We find excellent qualitative agreement. Furthermore, because of the strong correlations that are present, GaAs in a magnetic field presents an excellent opportunity to study the exciton-exciton correlations themselves. We investigate the coherence of the exciton-exciton correlations as the temperature and free-carrier density are varied, and find a surprising sensitivity of the exciton-exciton correlation coherence to these parameters. [S0163-1829(99)02331-0]. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Forschungszentrum Julich, John von Neumann Inst Comp, D-52425 Julich, Germany. RP Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 66 TC 39 Z9 39 U1 1 U2 4 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 AUG 15 PY 1999 VL 60 IS 7 BP 4731 EP 4748 DI 10.1103/PhysRevB.60.4731 PG 18 WC Physics, Condensed Matter SC Physics GA 230FQ UT WOS:000082241500064 ER PT J AU Cheong, HM Zhang, Y Norman, AG Perkins, JD Mascarenhas, A Cheng, KY Hsieh, KC AF Cheong, HM Zhang, Y Norman, AG Perkins, JD Mascarenhas, A Cheng, KY Hsieh, KC TI Resonance Raman scattering studies of composition-modulated GaP/InP short-period superlattices SO PHYSICAL REVIEW B LA English DT Article ID LATERAL COMPOSITION MODULATION; LAYER ORDERING PROCESS; ALLOYS AB Resonance Raman scattering and electroreflection measurements on laterally composition modulated GaP/InP short-period superlattices are presented. The electroreflectance spectra give the fundamental band-gap energy of the lateral superlattice at 1.69+/-0.05 eV, which is about 210 meV lower than the band-gap energy of a GaInP random alloy with the same overall composition. In resonance Raman spectra measured with the polarization of both excitation and scattered photons along the composition modulation direction, the GaP-like longitudinal optical phonon redshifts by 4.0+/-0.5 cm(-1) near the resonance with the fundamental energy gap. A comparison of the experimental data with a model calculation gives the average In composition in the In-rich region as 0.70+/-0.02, and the average Ga composition in the Ga-rich region as 0.68+/-0.02. [S0163-1829(99)04531-2]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Illinois, Dept Elect & Comp Engn, Urbana, IL 61801 USA. RP Cheong, HM (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI Norman, Andrew/F-1859-2010; Cheong, Hyeonsik/D-7424-2012 OI Norman, Andrew/0000-0001-6368-521X; Cheong, Hyeonsik/0000-0002-2347-4044 NR 21 TC 6 Z9 6 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 AUG 15 PY 1999 VL 60 IS 7 BP 4883 EP 4888 DI 10.1103/PhysRevB.60.4883 PG 6 WC Physics, Condensed Matter SC Physics GA 230FQ UT WOS:000082241500084 ER PT J AU Feibelman, PJ AF Feibelman, PJ TI Self-diffusion along step bottoms on Pt(111) SO PHYSICAL REVIEW B LA English DT Article ID ABINITIO MOLECULAR-DYNAMICS; TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; ULTRASOFT PSEUDOPOTENTIALS; CRYSTAL-GROWTH; SURFACES; METALS; MORPHOLOGY; TRANSITION; PT/PT(111) AB First-principles total energies of periodic vicinals are used to estimate barriers for Pt-adatom diffusion along straight and kinked steps on Pt(111), and around a corner where straight steps intersect. In all cases studied, hopping diffusion has a lower barrier than concerted substitution. In conflict with simulations of dendritic Pt island formation on Pt(111), hopping from a corner site to a step whose riser is a (111) microfacet is predicted to be more facile than to one whose riser is a (100). [S0163-1829(99)05331-X]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Feibelman, PJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 42 TC 36 Z9 37 U1 0 U2 5 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 AUG 15 PY 1999 VL 60 IS 7 BP 4972 EP 4981 DI 10.1103/PhysRevB.60.4972 PG 10 WC Physics, Condensed Matter SC Physics GA 230FQ UT WOS:000082241500096 ER PT J AU Chao, KJ Zhang, ZY Ebert, P Shih, CK AF Chao, KJ Zhang, ZY Ebert, P Shih, CK TI Substrate effects on the formation of flat Ag films on (110) surfaces of III-V compound semiconductors SO PHYSICAL REVIEW B LA English DT Article ID GAAS(110) AB Ag films grown at 135 K on (110) surfaces of III-V compound semiconductors and annealed at room temperature are investigated by scanning tunneling microscopy and low-energy electron diffraction. Ag films on Ga-V semiconductors are well ordered, atomically hat, and exhibit a specific critical thickness, which is a function of the substrate material. Films grown on In-V semiconductors are still rather flat, but significantly more disordered. The (111) oriented Ag films on III-arsenides and III-phosphides exhibit a clear twofold superstructure. Films on m-antimonides exhibit threefold low-energy electron diffraction images. The morphology of the Ag films can be explained on the basis of the electronic growth mechanism. [S0163-1829(99)10831-2]. C1 Univ Texas, Dept Phys, Austin, TX 78712 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Forschungszentrum Julich, Inst Festkorperforsch, D-52425 Julich, Germany. RP Univ Texas, Dept Phys, Austin, TX 78712 USA. OI Ebert, Ph./0000-0002-2022-2378 NR 13 TC 20 Z9 20 U1 2 U2 3 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 AUG 15 PY 1999 VL 60 IS 7 BP 4988 EP 4991 DI 10.1103/PhysRevB.60.4988 PG 4 WC Physics, Condensed Matter SC Physics GA 230FQ UT WOS:000082241500098 ER PT J AU Mahan, GD Woods, LM AF Mahan, GD Woods, LM TI Phonon-modulated electron-electron interactions SO PHYSICAL REVIEW B LA English DT Article ID TIGHT-BINDING; SUPERCONDUCTIVITY; CONDUCTIVITY; METALS AB The phonon modulation of electron-electron interactions are calculated for solids described by tight-binding models. In some cases the interaction can be larger than the usual electron-phonon effects. [S0163-1829(99)00828-0]. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Mahan, GD (reprint author), Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. NR 9 TC 5 Z9 5 U1 2 U2 3 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 AUG 15 PY 1999 VL 60 IS 8 BP 5276 EP 5281 DI 10.1103/PhysRevB.60.5276 PG 6 WC Physics, Condensed Matter SC Physics GA 234HL UT WOS:000082478600031 ER PT J AU Kang, JS Olson, CG Hedo, M Inada, Y Yamamoto, E Haga, Y Onuki, Y Kwon, SK Min, BI AF Kang, JS Olson, CG Hedo, M Inada, Y Yamamoto, E Haga, Y Onuki, Y Kwon, SK Min, BI TI Photoemission study of an f-electron superconductor: CeRu2 SO PHYSICAL REVIEW B LA English DT Article ID 4F ELECTRONS; SPECTRA; CE; HYBRIDIZATION; TRANSITION; CHARACTER; TRANSPORT; PHASE; PR AB Photoemission study has been performed for a high-quality single crystal of CeRu2, including resonant photoemission near the Ce 4d-->4f absorption edge and high-resolution photoemission at a low-photon energy. Resonant photoemission study provides evidence for the large hybridization between Ce 4f and conduction electrons, indicating mixed-valence in CeRu2. It is found that the line shape of the high-resolution spectrum near the Fermi level depends on the experimental conditions and the sample surface treatment. Comparison of photoemission data to the calculated density of states reveals that band calculations provide a reasonably good description of the electronic structure of CeRu2. [S0163-1829(99)01831-7]. C1 Catholic Univ Korea, Dept Phys, Puchon 422743, South Korea. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Osaka Univ, Grad Sch Sci, Toyonaka, Osaka 560, Japan. Japan Atom Energy Res Inst, Advance Sci Res Ctr, Tokai, Ibaraki 31911, Japan. Pohang Univ Sci & Technol, Dept Phys, Pohang 790784, South Korea. RP Kang, JS (reprint author), Catholic Univ Korea, Dept Phys, Puchon 422743, South Korea. NR 30 TC 18 Z9 18 U1 1 U2 2 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 AUG 15 PY 1999 VL 60 IS 8 BP 5348 EP 5353 DI 10.1103/PhysRevB.60.5348 PG 6 WC Physics, Condensed Matter SC Physics GA 234HL UT WOS:000082478600041 ER PT J AU Wei, SH Zunger, A AF Wei, SH Zunger, A TI Predicted band-gap pressure coefficients of all diamond and zinc-blende semiconductors: Chemical trends SO PHYSICAL REVIEW B LA English DT Article ID ABSOLUTE DEFORMATION POTENTIALS; III-V; ELECTRONIC-PROPERTIES; QUANTUM-WELLS; BULK MODULI; DEPENDENCE; HETEROSTRUCTURES; ALLOYS; GAAS; PHOTOLUMINESCENCE AB We have studied systematically the chemical trends of the band-gap pressure coefficients of all group IV, m-V, and Il-VI semiconductors using first-principles band-structure method. We have also calculated the individual "absolute" deformation potentials of the valence-band maximum (VBM) and conduction-band minimum (CBM). We find that (I) the volume deformation potentials of the Gamma(6c) CBM are usually large and always negative, while (2) the volume deformation potentials of the Gamma(8 nu) VBM state are usually small and negative for compounds containing occupied valence d state but positive for compounds without occupied valence d orbitals. Regarding the chemical trends of the band-gap pressure coefficients, we find that (3) a(p)(Gamma-Gamma) decreases as the ionicity increases (e.g., from Ge --> GaAs --> ZnSe), (4) a(p)(Gamma-Gamma) increases significantly as anion atomic number increases (e.g., from GaN --> GaP --> GaAs --> GaSb), (5) a(p)(Gamma-Gamma) decreases slightly as cation atomic number increases (e.g., from AlAs --> GaAs --> InAs), (6) the variation of a(p)(Gamma-L) are relatively small and follow similar trends as a(p)(Gamma-Gamma), and (7) the magnitude of a(p)(Gamma-chi), small and usually negative, but are sometimes slightly positive for compounds containing first-row elements. Our calculated chemical trends are explained in terms of the energy levels of the atomic valence orbitals and coupling between these orbital. In light of the above, we suggest that "empirical rule" of the pressure coefficients should be modified. [S0163-1829(99)00532-9]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 48 TC 340 Z9 354 U1 5 U2 56 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 AUG 15 PY 1999 VL 60 IS 8 BP 5404 EP 5411 DI 10.1103/PhysRevB.60.5404 PG 8 WC Physics, Condensed Matter SC Physics GA 234HL UT WOS:000082478600048 ER PT J AU Wang, LW Wei, SH Mattila, T Zunger, A Vurgaftman, I Meyer, JR AF Wang, LW Wei, SH Mattila, T Zunger, A Vurgaftman, I Meyer, JR TI Multiband coupling and electronic structure of (InAs)(n)/(GaSb)(n) superlattices SO PHYSICAL REVIEW B LA English DT Article ID DOT-P METHOD; OPTICAL-ABSORPTION; BAND OFFSETS; QUANTUM DOTS; INAS/GASB SUPERLATTICES; SUPER-LATTICES; COMMON-ATOM; HETEROSTRUCTURES; INAS/GA1-XINXSB; ANISOTROPY AB The electronic structure of abrupt (InAs)(n)/(GaSb)(n) superlattices is calculated using a plane wave pseudopotential method and the more approximate eight band k.p method. The k.p parameters are extracted from the pseudopotential band structures of the zinc-blende constituents near the Gamma point. We find, in general, good agreement between pseudopotencial results and k.p results, except as follows. (1) The eight band k.p significantly underestimates the electron confinement energies for n less than or equal to 20. (2) While the pseudopotential calculation exhibits (a) a zone center electron-heavy hole coupling manifested by band anticrossing at n=28, and (b) a light hole-heavy hole coupling and anticrossing around n=13, these features are absent in the kp model. (3) As k.p misses atomistic features, it does not distinguish the C-2v symmetry of a superlattice with no-common-atom such as InAs/GaSb from the D-2d symmetry of a superlattice that has a common atom, e.g., InAs/GaAs. Consequently, kp lacks the strong in-plane polarization anisotropy of the interband transition evident in the pseudopotential calculation. Since the pseudopotential band gap is larger than the k.p values, and most experimental band gaps are even smaller than the k.p band gap, we conclude that to understand the experimental results one must consider physical mechanisms beyond what is included here (e.g., interdiffusing, rough interfaces, and internal electric fields), rather than readjust the kp parameters. [S0163-1829(99)07531-1]. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. USN, Res Lab, Washington, DC 20375 USA. RP Wang, LW (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 43 TC 56 Z9 57 U1 5 U2 17 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 AUG 15 PY 1999 VL 60 IS 8 BP 5590 EP 5596 DI 10.1103/PhysRevB.60.5590 PG 7 WC Physics, Condensed Matter SC Physics GA 234HL UT WOS:000082478600069 ER PT J AU de Abajo, FJG AF de Abajo, FJG TI Multiple scattering of radiation in clusters of dielectrics SO PHYSICAL REVIEW B LA English DT Article ID AUGER-ELECTRON DIFFRACTION; PHOTONIC BAND-STRUCTURE; ENERGY-LOSS; PHOTOELECTRON DIFFRACTION; HETEROGENEOUS SYSTEMS; CHARGED-PARTICLES; QUASI-CRYSTALS; MEDIA; PROPAGATION; SPHERES AB A fast, accurate, and general technique for solving Maxwell's equations in the presence of a finite cluster of arbitrarily disposed dielectric objects is presented. The electromagnetic field is first decomposed into multipoles with respect to centers close to each of the objects of the cluster and multiple scattering is carried out until convergence is achieved. Radiation scattering cross sections are obtained using this method for clusters formed by homogeneous spheres and coated spheres made of different materials (Al, Si, and SiO2), including magnetic ones. Near- and far-field distributions are offered as well. [S0163-1829(99)00531-7]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Fac Informat, Dept CCIA, Donostia Int Phys Ctr, San Sebastian, Spain. UPV, EHU, CSIC, Ctr Mixto, San Sebastian, Spain. RP de Abajo, FJG (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Garcia de Abajo, Javier/A-6095-2009; DONOSTIA INTERNATIONAL PHYSICS CTR., DIPC/C-3171-2014 OI Garcia de Abajo, Javier/0000-0002-4970-4565; NR 56 TC 87 Z9 87 U1 0 U2 8 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 AUG 15 PY 1999 VL 60 IS 8 BP 6086 EP 6102 DI 10.1103/PhysRevB.60.6086 PG 17 WC Physics, Condensed Matter SC Physics GA 234HL UT WOS:000082478600126 ER PT J AU de Abajo, FJG AF de Abajo, FJG TI Relativistic description of valence energy losses in the interaction of fast electrons with clusters of dielectrics: Multiple-scattering approach SO PHYSICAL REVIEW B LA English DT Article ID LOSS SPECTRA; HETEROGENEOUS SYSTEMS; CHARGED-PARTICLES; SURFACE; SPHERES; EXCITATIONS; MICROSCOPY; BEAMS; MEDIA; COMPOSITE AB A fully relativistic description of valence energy losses suffered by fast electrons passing near finite clusters of arbitrarily disposed dielectric objects is presented using an accurate technique suited to solve Maxwell's equations. The method is based upon an expansion of the electromagnetic field in terms of multipoles around each of the objects of the cluster. Multiple elastic scattering of those multipole expansions is then performed until convergence is achieved. The energy loss, obtained from the induced electric field acting back on the electron, is computed in a time proportional to the square of the number of objects in the cluster, N-2. Numerical examples are presented for various clusters formed by N = 1-198 homogeneous spheres made of SiO2 and Al, and also for clusters of Si spheres coated with SiO2. Both relativistic effects and the interaction between the constituents of the cluster are shown to be of primary importance in the understanding of the position and magnitude of the features exhibited by the calculated electron-energy-loss spectra. [S0163-1829(99)00631-1]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Fac Informat, Dept CCIA, Donostia Int Phys Ctr, San Sebastian, Spain. UPV, EHU, CSIC, Ctr Mixto, San Sebastian, Spain. RP de Abajo, FJG (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Garcia de Abajo, Javier/A-6095-2009; DONOSTIA INTERNATIONAL PHYSICS CTR., DIPC/C-3171-2014 OI Garcia de Abajo, Javier/0000-0002-4970-4565; NR 46 TC 7 Z9 7 U1 0 U2 2 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 AUG 15 PY 1999 VL 60 IS 8 BP 6103 EP 6112 DI 10.1103/PhysRevB.60.6103 PG 10 WC Physics, Condensed Matter SC Physics GA 234HL UT WOS:000082478600127 ER PT J AU Chirita, M Sooryakumar, R Xia, H Monteiro, OR Brown, IG AF Chirita, M Sooryakumar, R Xia, H Monteiro, OR Brown, IG TI Observation of guided longitudinal acoustic modes in hard supported layers SO PHYSICAL REVIEW B LA English DT Article ID BRILLOUIN-SCATTERING; FILMS; SILICON AB We report experimental as well as theoretical evidence for the occurrence of a high-frequency acoustic excitation, identified as a longitudinal guided mode, in elastically hard films supported on a soft substrate. While existence criteria related to the transverse and longitudinal sound Velocities in the film and substrate argue for strong decay channels into the substrate, the excitation is evident as a clear peak in the Brillouin light scattering spectra. A Green's function formalism accounts for the existence of this excitation and provides insight into its properties as illustrated for diamond-like-carbon layers deposited on silicon. [S0163-1829(99)50832-1]. C1 Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Xia, H (reprint author), Ohio State Univ, Dept Phys, 174 W 18th Ave, Columbus, OH 43210 USA. NR 20 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 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD AUG 15 PY 1999 VL 60 IS 8 BP R5153 EP R5156 DI 10.1103/PhysRevB.60.R5153 PG 4 WC Physics, Condensed Matter SC Physics GA 234HL UT WOS:000082478600016 ER PT J AU Pizzagalli, L Catellani, A Galli, G Gygi, F Baratoff, A AF Pizzagalli, L Catellani, A Galli, G Gygi, F Baratoff, A TI Theoretical study of the (3x2) reconstruction of beta-SiC(001) SO PHYSICAL REVIEW B LA English DT Article ID SURFACE RECONSTRUCTION; 3C-SIC(001) SURFACES; ATOMIC-STRUCTURE; GROWTH AB By means of ab initio molecular dynamics and band-stricture calculations, as well as using calculated scanning tunneling microscopy (STM) images, we have singled out one structural model for the (3 x 2) reconstruction of the Si-terminated (001) surface of cubic SiC, among several proposed in the literature. This is an alternate dimer-row model, with an excess Si coverage of 1/3, yielding STM images in good accord with recent measurements. [S0163-1829(99)51232-0]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland. CNR, MASPEC, I-43010 Parma, Italy. RP Pizzagalli, L (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. EM pizza@llnl.gov RI Pizzagalli, Laurent/A-1445-2013 NR 32 TC 14 Z9 14 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 AUG 15 PY 1999 VL 60 IS 8 BP R5129 EP R5132 DI 10.1103/PhysRevB.60.R5129 PG 4 WC Physics, Condensed Matter SC Physics GA 234HL UT WOS:000082478600010 ER PT J AU Wright, AF AF Wright, AF TI Influence of crystal structure on the lattice sites and formation energies of hydrogen in wurtzite and zinc-blende GaN SO PHYSICAL REVIEW B LA English DT Article ID N-TYPE; DEFECTS AB Charge-state calculations based on density-functional theory are used to study the formation energy of hydrogen in wurtzite and zinc-blende GaN as a function of Fermi level. Comparison of these results reveals notable differences including a 0.56 eV lower formation energy for H-2 in wurtzite, and different configurations for H-2 and H- in the two crystal structures. Furthermore, H+ is found to be equally stable at bond-centered and antibonding sites in wurtzite, whereas it is unstable at a bond-centered site in zinc blende. N-H+ stretch-mode vibration frequencies, clustering of H+ in p-type material, and diffusion barriers for H- are investigated in wurtzite GaN. A diffusion barrier of 1.6 eV is found for H- in wurtzite GaN, significantly lower than a previous estimate, and a tendency for H+ clustering in p-type material is found. [S0163-1 829(99)50432-3]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 23 TC 23 Z9 23 U1 1 U2 6 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 AUG 15 PY 1999 VL 60 IS 8 BP R5101 EP R5104 DI 10.1103/PhysRevB.60.R5101 PG 4 WC Physics, Condensed Matter SC Physics GA 234HL UT WOS:000082478600003 ER PT J AU Appelquist, T Cohen, AG Schmaltz, M AF Appelquist, T Cohen, AG Schmaltz, M TI A new constraint on strongly coupled field theories SO PHYSICAL REVIEW D LA English DT Article ID CHIRAL PHASE-TRANSITION; ABELIAN GAUGE-THEORIES; C-THEOREM; SUPERSYMMETRIC SP(N-C); 4 DIMENSIONS; DUALITY; CONFINEMENT AB We propose a new constraint on the structure of strongly coupled, asymptotically free field theories. The constraint takes the form of an inequality limiting the number of degrees of freedom in the infrared description of a theory relative to the number of underlying, ultraviolet degrees of freedom. We apply the inequality to a variety of theories (both supersymmetric and nonsupersymmetric), where it agrees with all known results and leads to interesting new constraints on low energy spectra. We discuss the relation of this constraint to renormalization group c theorems. [S0556-2821(99)02416-9]. C1 Yale Univ, Dept Phys, New Haven, CT 06511 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. Stanford Univ, SLAC, Stanford, CA 94309 USA. RP Yale Univ, Dept Phys, New Haven, CT 06511 USA. EM thomas.appelquist@yale.edu; cohen@bu.eru; schmaltz@slac.stanford.edu NR 34 TC 127 Z9 127 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD AUG 15 PY 1999 VL 60 IS 4 AR 045003 DI 10.1103/PhysRevD.60.045003 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 227ZQ UT WOS:000082110400025 ER PT J AU Csaki, C Russo, J Sfetsos, K Terning, J AF Csaki, C Russo, J Sfetsos, K Terning, J TI Supergravity models for (3+1)-dimensional QCD SO PHYSICAL REVIEW D LA English DT Article ID STRING THEORY; GLUEBALLS AB The most general black M5-brane solution of eleven-dimensional supergravity (with a flat R-4 spacetime in the brane and a regular horizon) is characterized by charge, mass and two angular momenta. We use this metric to construct general dual models of large-N QCD (at strong coupling) that depend on two free parameters. The mass spectrum of scalar particles is determined analytically (in the WKB approximation) and numerically in the whole two-dimensional parameter space. We compare the mass spectrum with analogous results from lattice calculations, and find that the supergravity predictions are close to the lattice results everywhere on the two dimensional parameter space except along a special line. We also examine the mass spectrum of the supergravity Kaluza-Klein (KK) modes and find that the KK modes along the compact D-brane coordinate decouple from the spectrum for large angular momenta. There are however KK modes charged under a U(1) X U(1) global symmetry which do not decouple anywhere on the parameter space. General formulas for the string tension and action are also given. [S0556-2821(99)00116-2]. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. Univ Buenos Aires, Dept Fis, RA-1428 Buenos Aires, DF, Argentina. CERN, Div Theory, CH-1211 Geneva 23, Switzerland. RP Csaki, C (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM ccsaki@lbl.gov; russo@df.uba.ar; sfetsos@mail.cern.ch; terning@alvin.lbl.gov NR 24 TC 28 Z9 28 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1550-7998 EI 1550-2368 J9 PHYS REV D JI Phys. Rev. D PD AUG 15 PY 1999 VL 60 IS 4 AR 044001 DI 10.1103/PhysRevD.60.044001 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 227ZQ UT WOS:000082110400009 ER PT J AU Cruz, LR Kazmerski, LL Moutinho, HR Hasoon, F Dhere, RG de Avillez, R AF Cruz, LR Kazmerski, LL Moutinho, HR Hasoon, F Dhere, RG de Avillez, R TI The influence of post-deposition treatment on the physical properties of CdTe films deposited by stacked elemental layer processing SO THIN SOLID FILMS LA English DT Article DE CdTe; solar cells; CdCl2 treatment; characterisation ID SOLAR-CELLS; THIN-FILMS AB Cadmium telluride thin films have been deposited on glass and glass/SnO2/CdS substrates using the stacked elemental layer (SEL) technique. After the films were deposited, they were subjected to the conventional heat treatment in the presence of a CdCl2/methanol solution. The samples were analyzed, before and after treatment, by X-ray diffraction, atomic force microscopy, cathodoluminescence and energy dispersive X-ray spectrometry. The results suggest that the treatment promotes grain growth, decreases defect concentration, and gives rise to the formation of a CdTe1-xSx solid solution, which replaces the CdTe original layer. The existence of this solid solution was evidenced by a reduction in the lattice parameter relative to untreated samples and confirmed by EDS analysis of treated and untreated glass/SnO2/CdS/CdTe structures. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Inst Militar Engn, BR-22290270 Rio De Janeiro, Brazil. Natl Renewable Energy Lab, Golden, CO 80401 USA. Pontificia Univ Catolica Rio de Janeiro, BR-22543900 Rio De Janeiro, Brazil. RP Cruz, LR (reprint author), Inst Militar Engn, Praca Gen Tiburcio 80, BR-22290270 Rio De Janeiro, Brazil. RI de Avillez, Roberto/A-2592-2010 OI de Avillez, Roberto/0000-0002-2192-1082 NR 10 TC 19 Z9 19 U1 1 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD AUG 15 PY 1999 VL 350 IS 1-2 BP 44 EP 48 DI 10.1016/S0040-6090(99)00227-8 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 226MH UT WOS:000082023400008 ER PT J AU Kwok, ESC Buchholz, BA Vogel, JS Turteltaub, KW Eastmond, DA AF Kwok, ESC Buchholz, BA Vogel, JS Turteltaub, KW Eastmond, DA TI Dose-dependent binding of ortho-phenylphenol to protein but not DNA in the urinary bladder of male F344 rats SO TOXICOLOGY AND APPLIED PHARMACOLOGY LA English DT Article DE ortho-phenylphenol (OPP); fungicide; disinfectant; protein adduct; DNA adduct; rat; accelerator mass spectrometry (AMS); pesticide ID SODIUM ORTHO-PHENYLPHENATE; ACCELERATOR MASS-SPECTROMETRY; ACUTE MYELOID-LEUKEMIA; O-PHENYLPHENOL; CARCINOGENESIS; PHENYLHYDROQUINONE; INDUCTION; CYTOTOXICITY; METABOLITES; INHIBITION AB ortho-Phenvlphenol (OPP) is a widely used fungicide and antibacterial agent that is also known to be highly effective in inducing bladder tumors in male F344 rats. At present, neither the role of the urinary bladder in the bioactivation of OPP metabolites nor the nature of the molecular target is understood. To address these issues, we investigated the relationship between OPP dosage and macromolecular adduct formation in the urinary bladder of male F344 rats. Male F344 rats were treated with 0, 15, 50, 125, 250, 500, 1000 mg/kg of OPP and its radiocarbon analogue via oral gavage. The dosed rats were euthanized after 24 h, and the proteins were extracted from the liver, kidney, and bladder. The amount of radioactivity associated with the extracted protein was quantified using highly sensitive accelerator mass spectrometry. Protein binding in liver and kidney exhibited a linear or modest curvilinear relationship over the dose range studied. In the urinary bladder, however, a pronounced non-linear relationship between protein adduct levels and administered dose was observed. The measured protein adduct levels were in agreement with the predicted concentrations of phenylbenzoquinone based on a proposed mechanism involving free phenylhydroquinone autoxidation in the urine. Unlike protein binding, DNA adducts measured from the same bladder samples did not show a significant difference from the control group. These data are consistent with the hypothesis that OPP is an indirect acting carcinogen, and that regenerative hyperplasia due to OPP-metabolite cytotoxicity and/or binding of OPP metabolites to protein targets may play an important role in OPP-induced bladder carcinogenesis. (C) 1999 Academic Press. C1 Univ Calif Riverside, Environm Toxicol Program, Riverside, CA 92521 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. RP Kwok, ESC (reprint author), SSD, CalEPA Air Resources Board, 2020 L St, Sacramento, CA 95812 USA. RI Buchholz, Bruce/G-1356-2011 NR 44 TC 22 Z9 23 U1 0 U2 4 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0041-008X J9 TOXICOL APPL PHARM JI Toxicol. Appl. Pharmacol. PD AUG 15 PY 1999 VL 159 IS 1 BP 18 EP 24 DI 10.1006/taap.1999.8722 PG 7 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA 230RV UT WOS:000082264900003 PM 10448121 ER PT J AU Valdes, H Rayon, VM Sordo, JA AF Valdes, H Rayon, VM Sordo, JA TI On the violation of Legon-Millen's rules for predicting angular geometries of hydrogen-bonded dimers: an ab initio study SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DER-WAALS COMPLEXES; CENTER-DOT-HCL; ROTATIONAL SPECTRUM; CHEMICAL-REACTIONS; ELECTRON-DONOR; GAS-PHASE; CLF; PROGRAM; FURAN; BORON AB The potential energy surfaces of furan ... HCl, furan ... ClF, thiophene ... HCl, and thiophene ... ClF complexes were extensively explored at the MP2/aug-cc-pVDZ level. QCISD(T)/aug-cc-pVDZ//MP2/aug-cc-pVDZ calculations were carried out to improve the energy estimates. Ab initio calculations confirm that, as demonstrated by recent experimental work, there are exceptions to the third Legon-Millen's :rule for predicting angular geometries of hydrogen-bonded dimers. Besides electrostatic considerations, charge transfer contributions may play an important role in determining the experimentally observed geometry of the furan ... ClF complex. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Oviedo, Fac Quim, Dept Quim Fis & Analit, Lab Quim Computac, E-33006 Oviedo, Asturias, Spain. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Sordo, JA (reprint author), Univ Oviedo, Fac Quim, Dept Quim Fis & Analit, Lab Quim Computac, Julian Claveria 8, E-33006 Oviedo, Asturias, Spain. EM jasg@dwarfl.quimica.uniovi.es RI Valdes, Haydee/D-8612-2013 NR 35 TC 12 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 EI 1873-4448 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD AUG 13 PY 1999 VL 309 IS 3-4 BP 265 EP 273 DI 10.1016/S0009-2614(99)00687-9 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 227YH UT WOS:000082107200019 ER PT J AU Stephenson, SA Verity, K Ashworth, LK Clements, JA AF Stephenson, SA Verity, K Ashworth, LK Clements, JA TI Localization of a new prostate-specific antigen-related serine protease gene, KLK4, is evidence for an expanded human kallikrein gene family cluster on chromosome 19q13.3-13.4 SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID SEQUENCE-ANALYSIS; CDNA; EXPRESSION; LOCUS; IDENTIFICATION; EVOLUTION; PROMOTER; BREAST; CANCER AB The human tissue kallikrein (KLK) family of serine proteases, which is important in post-translational processing events, currently consists of just three genes-tissue kallikrein (KLK1), KLK2, and prostate-specific antigen (PSA) (KLK3)-clustered at chromosome 19q13.3-13.4. We identified an expressed sequence tag from an endometrial carcinoma cDNA library with 50% identity to the three known KLK genes. Primers designed to putative exon 2 and exon 3 regions from this novel kallikrein-related sequence were used to polymerase chain reaction-screen five cosmids spanning 130 kb around the KIK locus on chromosome 19. This new gene, which we have named KLK4, is 25 kb downstream of the KLK2 gene and follows a region that includes two other putative KLK-like gene fragments KLK4 spans 5.2 kb, has an identical genomic structure-five exons and four introns-to the other KLK genes and is transcribed on the reverse strand, in the same direction as KLK1 but opposite to that of KLK2 and KLK3. It encodes a 254-amino acid prepro-serine protease that is most similar (78% identical) to pig enamel matrix serine protease but is also 37% identical to PSA. These data suggest that the human kallikrein gene family locus on chromosome 19 is larger than previously thought and also indicate a greater sequence divergence within this family compared with the highly conserved rodent kallikrein genes. C1 Queensland Univ Technol, Sch Life Sci, Ctr Mol Biotechnol, Brisbane, Qld 4001, Australia. Prince Henrys Inst Med Res, Clayton, Vic 3168, Australia. Univ Calif Lawrence Livermore Natl Lab, Ctr Human Genome, Livermore, CA 94551 USA. RP Clements, JA (reprint author), Queensland Univ Technol, Sch Life Sci, Ctr Mol Biotechnol, GPO Box 2434, Brisbane, Qld 4001, Australia. RI Stephenson, Sally-Anne/I-9801-2012; OI Stephenson, Sally-Anne/0000-0003-3227-2476; Clements, Judith/0000-0001-6026-1964 NR 34 TC 83 Z9 86 U1 0 U2 1 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD AUG 13 PY 1999 VL 274 IS 33 BP 23210 EP 23214 DI 10.1074/jbc.274.33.23210 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 226GV UT WOS:000082012800043 PM 10438493 ER PT J AU Laouar, A Glesne, D Huberman, E AF Laouar, A Glesne, D Huberman, E TI Involvement of protein kinase C-beta and ceramide in tumor necrosis factor-alpha-induced but not Fas-induced apoptosis of human myeloid leukemia cells SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID NF-KAPPA-B; INTERLEUKIN-1-BETA CONVERTING-ENZYME; MEDIATED APOPTOSIS; HL-60 CELLS; SIGNAL-TRANSDUCTION; TNF RECEPTOR-1; CD95(FAS/APO-1)-MEDIATED APOPTOSIS; MACROPHAGE DIFFERENTIATION; INDUCED ACTIVATION; DEPENDENT PATHWAY AB The role of protein kinase C-beta (PKC-beta) in apoptosis induced by tumor necrosis factor (TNF)-alpha and anti-Fas monoclonal antibody (mAb) in the human myeloid HL-60 leukemia cell line was studied by using its variant HL-525, which is deficient in PKC-beta. In contrast to the parental HL-60 cells, HL-525 is resistant to TNF-alpha-induced apoptosis but sensitive to anti-Fas mAb-induced apoptosis. Both cell types expressed similar levels of the TNF-receptor I, whereas the Fas receptor was detected only in HL-525 cells. Transfecting the HL-525 cells with an expression vector containing PKC-beta reestablished their susceptibility to TNF-alpha-induced apoptosis. The apoptotic effect of TNF-alpha in HL-60 and the transfectants was abrogated by fumonisin, an inhibitor of ceramide generation, and by the peptide Ac-YVAD-BoMX, an inhibitor of caspase-1 and -4. Supplementing HL-525 cells with exogenous ceramides bypassed the PKC-beta deficiency and induced apoptosis, which was also restrained by the caspase-1 and -4 inhibitor. The apoptotic effect of anti-Fas mAb in HL-525 cells was abrogated by the antioxidants N-acetylcysteine and glutathione and by the peptide z-DEVD-FMK, an inhibitor of caspase-3 and -7. We suggest that TNF-alpha-induced apoptosis involves PKC-beta and then ceramide and, in turn, caspase-1 and/or -4, whereas anti-Fas mAb-induced apoptosis utilizes reactive oxygen intermediates and, in turn, caspase-3 and/or -7. C1 Argonne Natl Lab, Biochip Technol Ctr, Gene Express & Funct Grp, Argonne, IL 60439 USA. RP Huberman, E (reprint author), Argonne Natl Lab, Biochip Technol Ctr, Gene Express & Funct Grp, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 73 TC 43 Z9 44 U1 0 U2 1 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD AUG 13 PY 1999 VL 274 IS 33 BP 23526 EP 23534 DI 10.1074/jbc.274.33.23526 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 226GV UT WOS:000082012800082 PM 10438532 ER PT J AU Guiochon, G AF Guiochon, G TI On the need to retain unregulated choice of high-performance liquid chromatography columns SO JOURNAL OF CHROMATOGRAPHY A LA English DT Letter DE columns C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 18 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD AUG 13 PY 1999 VL 852 IS 2 BP 603 EP 605 DI 10.1016/S0021-9673(99)00656-1 PG 3 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 230EZ UT WOS:000082240000025 PM 10481997 ER PT J AU Eisenberg, D AF Eisenberg, D TI Structural biology - How chaperones protect virgin proteins SO SCIENCE LA English DT Editorial Material C1 Univ Calif Los Angeles, DOE Lab Stuct Biol & Mol Med, Los Angeles, CA 90095 USA. RP Eisenberg, D (reprint author), Univ Calif Los Angeles, DOE Lab Stuct Biol & Mol Med, Los Angeles, CA 90095 USA. NR 10 TC 12 Z9 14 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 13 PY 1999 VL 285 IS 5430 BP 1021 EP 1022 DI 10.1126/science.285.5430.1021 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 226QV UT WOS:000082033100030 PM 10475844 ER PT J AU Horita, J Berndt, ME AF Horita, J Berndt, ME TI Abiogenic methane formation and isotopic fractionation under hydrothermal conditions SO SCIENCE LA English DT Article ID FISCHER-TROPSCH SYNTHESIS; MID-ATLANTIC RIDGE; CARBON-DIOXIDE; ZAMBALES OPHIOLITE; ORGANIC-COMPOUNDS; OCEANIC-CRUST; SERPENTINIZATION; REDUCTION; ORIGIN; GAS AB Recently, methane (CH4) of possible abiogenic origin has been reported from many Localities within Earth's crust, However, little is known about the mechanisms of abiogenic methane formation, or about isotopic fractionation during such processes. Here, a hydrothermally formed nickel-iron alloy was shown to catalyze the otherwise prohibitively slow formation of abiogenic CH4 from dissolved bicarbonate (HCO3-) under hydrothermal conditions. Isotopic fractionation by the catalyst resulted in delta(13)C values of the CH4 formed that are as Low as those typically observed for microbial methane, with similarly high CH4/(C2H6 + C3H8) ratios. These results, combined with the increasing recognition of nickel-iron alloy occurrence in oceanic crusts, suggest that abiogenic methane may be more widespread than previously thought. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Minnesota, Dept Geol & Geophys, Minneapolis, MN 55455 USA. RP Horita, J (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 49 TC 284 Z9 314 U1 10 U2 80 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 13 PY 1999 VL 285 IS 5430 BP 1055 EP 1057 DI 10.1126/science.285.5430.1055 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 226QV UT WOS:000082033100042 ER PT J AU Feller, D Dixon, DA AF Feller, D Dixon, DA TI Theoretical study of the heats of formation of small silicon-containing compounds SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MOLECULAR WAVE-FUNCTIONS; CONFIGURATION-INTERACTION CALCULATIONS; GAUSSIAN-BASIS SETS; BENCHMARK CALCULATIONS; TRIPLE EXCITATIONS; DIATOMIC HYDRIDES; FIRST-ROW; HYDROGEN; ENERGIES; ATOMS AB Heats of formation for nine small silicon-containing molecules were obtained from large basis set ab initio calculations using coupled cluster theory with a perturbative treatment of triple excitations. After adjusting the atomization energies for the finite basis set truncation error, core/valence correlation, scalar relativistic, higher order correlation, and atomic spin-orbit effects, the theoretical and experimental 0 K values of Delta H-f values were in good agreement. Using 106.6 kcal/mol as the heat of formation of silicon, we obtain Delta H-f values of SiH = 87.7 +/- 0.4 vs 89.5 +/- 0.7 (expt); SiH2((1)A(1)) = 64.1 +/- 0.4 vs 65.5 +/- 0.7 (expt); SiH2(B-3(1)) = 85.4 +/- 0.4 vs 86.5 +/- 0.7 (expt); SiH3 = 47.3 +/- 0.5 vs 47.7 +/- 1.2 (expt); SiH3 = 8.7 +/- 0.6 vs 9.5 +/- 0.5 (expt); Si-2 = 138.8 +/- 0.3 vs 139.2 (expt); Si2H6 = 19.7 +/- 0.5 vs 20.9 +/- 0.3 (expt); SiF = -14.8 +/- 0.4 vs -5.2 +/- 3 (expt); SiF2 = -151.7 +/- 0.5 vs -140.3 +/- 3 (expt); and SiF4 = -384.5 +/- 0.9 vs -384.9 +/- 0.2 (expt). Based on the present work, we suggest a number of revisions in the interpretation of the experimental data. Although a revision in Delta H(f)degrees(Si) to 107.4 +/- 0.6 kcal/mol at 0 K leads to improved agreement between theory and experiment for the SixHy compounds, it worsens agreement for SiF4. Given the remaining uncertainties in the theoretical approach, more definitive conclusions do not appear to be warranted. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Feller, D (reprint author), Pacific NW Lab, Environm Mol Sci Lab, MS K1-96,POB 999, Richland, WA 99352 USA. NR 58 TC 114 Z9 114 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD AUG 12 PY 1999 VL 103 IS 32 BP 6413 EP 6419 DI 10.1021/jp990596g PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 228AA UT WOS:000082111400019 ER PT J AU Tse, JS Klug, DD Tulk, CA Swainson, I Svensson, EC Loong, CK Shpakov, V Belosludov, VR Belosludov, RV Kawazoe, Y AF Tse, JS Klug, DD Tulk, CA Swainson, I Svensson, EC Loong, CK Shpakov, V Belosludov, VR Belosludov, RV Kawazoe, Y TI The mechanisms for pressure-induced amorphization of ice I-h SO NATURE LA English DT Article ID DENSITY AMORPHOUS WATER; X-RAY; LIQUID WATER; 1ST-ORDER TRANSITION; ELASTIC-CONSTANTS; DIFFRACTION; INSTABILITY; SCATTERING AB There has been considerable interest in the structure of liquid water at low temperatures and high pressure following the discovery of the high-density amorphous (HDA) phase of ice I-h (ref. 1). HDA ice forms at a pressure close to the extrapolated melting curve of ice, leading to the suggestion that it may have structure similar to that of dense water. On annealing, HDA ice transforms into a low-density amorphous (LDA) phase with a distinct phase boundary(2,3). Extrapolation of thermodynamic data along the HDA-LDA coexistence line into the liquid region has led to the hypothesis that there might exist a second critical point for water and the speculation that liquid water is mixture of two distinct structures with different densities(4,5). Here we critically examine this hypothesis. We use quasi-harmonic lattice-dynamics calculations to show that the amorphization mechanism in ice I-h changes from thermodynamic melting for T > 162 K to mechanical melting at lower temperatures. The vibrational spectra of ice I-h, LDA ice and quenched water also indicate a structure for LDA ice that differs from that of the liquid. These results call into question the validity of there being a thermodynamic connection between the amorphous and liquid phases of water. C1 Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R6, Canada. Argonne Natl Lab, Argonne, IL 60439 USA. Russian Acad Sci, Inst Inorgan Chem, Novosibirsk 630090, Russia. Tohoku Univ, Inst Mat Res, Sendai, Miyagi 9808577, Japan. RP Tse, JS (reprint author), Natl Res Council Canada, Steacie Inst Mol Sci, 100 Sussex Dr, Ottawa, ON K1A 0R6, Canada. EM John.Tse@NRC.CA RI Kawazoe, Yoshiyuki/C-2998-2011; Belosludov, Rodion/A-1748-2013; Tulk, Chris/R-6088-2016 OI Tulk, Chris/0000-0003-3400-3878 NR 24 TC 115 Z9 117 U1 6 U2 20 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 12 PY 1999 VL 400 IS 6745 BP 647 EP 649 DI 10.1038/23216 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 226QU UT WOS:000082032900047 ER PT J AU West, GB Brown, JH Enquist, BJ AF West, GB Brown, JH Enquist, BJ TI A general model for the structure and allometry of plant vascular systems SO NATURE LA English DT Article ID HYDRAULIC ARCHITECTURE; ACER-SACCHARUM; WOODY-PLANTS; RESISTANCE; SAPWOOD; BIOLOGY; TREES; FORM AB Vascular plants vary in size by about twelve orders of magnitude, and a single individual sequoia spans nearly this entire range as it grows from a seedling to a mature tree. Size influences nearly all of the structural, functional and ecological characteristics of organisms(1,2). Here we present an integrated model for the hydrodynamics, biomechanics and branching geometry of plants, based on the application of a general theory of resource distribution through hierarchical branching networks(3) to the case of vascular plants. The model successfully predicts a fractal-like architecture and many known scaling laws, both between and within individual plants, including allometric exponents which are simple multiple of 1/4. We show-that conducting tubes must taper and, consequently, that the resistance and fluid flow per tube are independent of the total path length and plant size. This resolves the problem of resistance increasing with length, thereby allowing plants to evolve vertical architectures and explaining why the maximum height of trees is about 100 m. It also explains why the energy use of plants in ecosystems is size independent. C1 Santa Fe Inst, Santa Fe, NM 87501 USA. Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Enquist, BJ (reprint author), Santa Fe Inst, 1399 Hyde Pk Rd, Santa Fe, NM 87501 USA. OI Enquist, Brian/0000-0002-6124-7096 NR 22 TC 623 Z9 701 U1 17 U2 221 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 12 PY 1999 VL 400 IS 6745 BP 664 EP 667 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 226QU UT WOS:000082032900053 ER PT J AU Baboul, AG Redfern, PC Sutjianto, A Curtiss, LA AF Baboul, AG Redfern, PC Sutjianto, A Curtiss, LA TI Li+-(diglyme)(2) and LiClO4-diglyme complexes: Barriers to lithium ion migration SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID GLYCOL DIMETHYL ETHER; POLYMER ELECTROLYTES; POLY(ETHYLENE OXIDE); MOLECULAR-DYNAMICS; CONFORMATIONAL-CHANGES; PHASE; SIMULATIONS; DIFFUSION; DIGLYME; GAS AB The lithium ion migration mechanism in Li+-(diglyme)(2) and LiClO4-diglyme complexes with coordination of Li+ by 3 to 6 oxygens has been investigated using ab initio molecular orbital theory. Local minima corresponding to different coordination sites of the Li+ cation and transition states between them have been located. The Li+ binding energies of the Li+-(diglyme)2 and LiClO4-diglyme complexes range from 94 to 122 and 167 to 188 kcal/mol, respectively. The binding energies increase with increasing coordination of Lif by oxygen, although the binding per Li-O bond decreases, and structures with higher coordination of Li+ by oxygen exhibit longer Li-O bond lengths than the ones with lower coordination number. The barrier heights for n + 1 --> n coordination of the cation by oxygen decrease with increasing coordination number n, with the smallest Li+ migration barriers (7-11 kcal/mol) occurring for complexes with the highest coordination numbers. The reaction coordinate for lithium ion migration between coordination sites is the torsional motion of the diglyme backbone. The implications of these results for Li+ migration in lithium poly(ethylene oxide) melts are discussed. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Curtiss, LA (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 28 TC 47 Z9 47 U1 1 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD AUG 11 PY 1999 VL 121 IS 31 BP 7220 EP 7227 DI 10.1021/ja990507d PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 227UK UT WOS:000082098200006 ER PT J AU Harlan, CJ Hascall, T Fujita, E Norton, JR AF Harlan, CJ Hascall, T Fujita, E Norton, JR TI The one-electron oxidation of an azazirconacyclobutene in the presence of B(C6F5)(3) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID POLYMERIZATION CATALYSTS; COMPLEXES; SYSTEMS; TRIS(PENTAFLUOROPHENYL)BORANE; HALIDES; HYDRIDE; ADDUCT; LIGAND C1 Columbia Univ, Dept Chem, New York, NY 10027 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Norton, JR (reprint author), Columbia Univ, Dept Chem, New York, NY 10027 USA. RI Fujita, Etsuko/D-8814-2013 NR 28 TC 36 Z9 36 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD AUG 11 PY 1999 VL 121 IS 31 BP 7274 EP 7275 DI 10.1021/ja984290j PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 227UK UT WOS:000082098200017 ER PT J AU Bernard, D Amiranoff, F Leemans, WP Esarey, E Joshi, C AF Bernard, D Amiranoff, F Leemans, WP Esarey, E Joshi, C TI Alternative interpretation of Nucl. Instr. and Meth. A 410 (1998) 357 (H, Dewa et al.) SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE laser wakefield acceleration; terawatt laser; high acceleration gradient; laser propagation measurement; wakefield measurement ID LASER WAKEFIELD ACCELERATION; INJECTED ELECTRONS; PLASMA; PULSES; WAVE; SCATTERING; GASES; RAMAN; AIR AB We consider a recent publication (H. Dewa et al., Nucl. Instr, and Meth. A 410 (1998) 357) of an experiment on ultra-high-energy laser wakefield acceleration of electrons, involving channeling of the laser pulse in the plasma. We find that in these experiments, channeling of the laser pulse may not have occurred and the detected electron signal may be background noise resulting from multiple electron scattering. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Ecole Polytech, LPNHE, CNRS, F-91128 Palaiseau, France. Ecole Polytech, IN2P3, F-91128 Palaiseau, France. Univ Paris 06, Ecole Polytech, CEA, Unite Mixte 7605 CNRS,Lab Utilisat Lasers Intense, F-91128 Palaiseau, France. Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. RP Bernard, D (reprint author), Ecole Polytech, LPNHE, CNRS, F-91128 Palaiseau, France. NR 27 TC 2 Z9 2 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1999 VL 432 IS 2-3 BP 227 EP 231 DI 10.1016/S0168-9002(99)00483-0 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 226RL UT WOS:000082035200004 ER PT J AU Smith, ES Carstens, T Distelbrink, J Eckhause, M Egiyan, H Elouadrhiri, L Ficenec, J Guidal, M Hancock, AD Hersman, FW Holtrop, M Jenkins, DA Kim, W Loukachine, K MacArthur, K Marchand, C Mecking, B Mutchler, G Schutt, D Smith, LC Smith, TP Taylor, S Tung, TY Weisenberger, A Welsh, RE AF Smith, ES Carstens, T Distelbrink, J Eckhause, M Egiyan, H Elouadrhiri, L Ficenec, J Guidal, M Hancock, AD Hersman, FW Holtrop, M Jenkins, DA Kim, W Loukachine, K MacArthur, K Marchand, C Mecking, B Mutchler, G Schutt, D Smith, LC Smith, TP Taylor, S Tung, TY Weisenberger, A Welsh, RE TI The time-of-flight system for CLAS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE CLAS; time of flight; plastic scintillator; particle identification ID SCINTILLATION-COUNTERS; DETECTOR; DELPHI AB The time of flight system for the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility is described. The system, covering an area of 206 m(2), is composed of scintillation counters 5.08 cm thick, 15 and 22 cm wide, and lengths which vary from 32 cm at the most forward angle to 450 cm at larger angles. All of the components of the system have been designed to optimize the time resolution. Event timing, achieved by leading-edge discrimination with time-walk correction, has been measured with cosmic rays, a laser pulser, and known particle interactions. The intrinsic time resolution varies from about 80 ps for the short counters to 160 ps for the longer counters. Reconstruction of interacting particles during the first period of operation yields an average time resolution for electrons of 163 ps. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Univ New Hampshire, Durham, NH 03824 USA. Coll William & Mary, Williamsburg, VA 23185 USA. Christopher Newport Univ, Newport News, VA 23606 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. CEA Saclay, F-91191 Gif Sur Yvette, France. Kyungpook Natl Univ, Taegu 702701, South Korea. Rice Univ, Houston, TX 77251 USA. Univ Virginia, Charlottesville, VA 22901 USA. RP Smith, ES (reprint author), Thomas Jefferson Natl Accelerator Facil, 12000 Jefferson Ave, Newport News, VA 23606 USA. NR 44 TC 78 Z9 78 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD AUG 11 PY 1999 VL 432 IS 2-3 BP 265 EP 298 DI 10.1016/S0168-9002(99)00484-2 PG 34 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 226RL UT WOS:000082035200008 ER PT J AU Cook, RE Goretta, KC Wolfenstine, J Nash, P Routbort, JL AF Cook, RE Goretta, KC Wolfenstine, J Nash, P Routbort, JL TI High-temperature deformation and defect chemistry of (La1-xSrx)(1-y)MnO3+delta SO ACTA MATERIALIA LA English DT Article DE functional ceramics; creep; high temperature; defects; La1-xSrxMnO3 ID OXIDE FUEL-CELLS; OXIDATION-REDUCTION BEHAVIOR; SR-DOPED LAMNO3; DIFFUSIONAL CREEP; OXYGEN PERMEATION; GIANT MAGNETORESISTANCE; MASS-TRANSPORT; PHASE-DIAGRAM; LAMNO3+/-DELTA; MODEL AB The creep behavior of (La1-xSrx)(1-y)MnO3+delta has been studied as a function of oxygen partial pressure (P-O2) and Sr concentration. Polycrystalline samples (x = 0.1, 0.2, 0.3) were deformed at 1523 K in constant-crosshead-speed compression tests in various atmospheres (10(-2) less than or equal to P-O2 less than or equal to 10(5) Pa). The material deformed by grain-boundary sliding accommodated by lattice diffusion with some possible cavitation and/or interface reaction control. The defect-chemistry model which is standard in the literature could not explain the dependence of the stress on P-O2 and the Sr concentration. A modified defect-chemistry model shows that cation vacancies controlled the creep rate at P-O2 less than or equal to 10(5) Pa for x = 0.3 and at low P-O2 for x = 0.1 and 0.2, and that oxygen vacancies were rate-controlling at high P-O2 for x = 0.1 and 0.2. (C) 1999 Acta Metallurgica me. Published by Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. USA, Res Lab, Adelphi, MD 20783 USA. IIT, Dept Mech Mat & Aerosp Engn, Chicago, IL 60616 USA. RP Cook, RE (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 60 TC 29 Z9 30 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD AUG 10 PY 1999 VL 47 IS 10 BP 2969 EP 2980 DI 10.1016/S1359-6454(99)00160-3 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 231DW UT WOS:000082293700011 ER PT J AU Bullard, JW Searcy, AW AF Bullard, JW Searcy, AW TI Equilibria and kinetics of mass transport between crystal facets: A comparison of two models SO ACTA MATERIALIA LA English DT Article DE theory & modeling; surface diffusion; microstructure; sintering ID LITHIUM-FLUORIDE; PARTICLES AB The principle of detailed balance is used to evaluate equilibrium between a crystal facet and a transport medium, and transition state theory is then used to evaluate the kinetics of transport between two facets of a particle of nonequilibrium shape. For each of two lest geometries undergoing volume-conserved shape changes, the transition state model predicts the same trajectories for detachment/attachment-limited transport as does a continuum model based on the crystalline formulation (Carter et al., Acta metall. mater., 1995, 43, 4309). Both models agree that reported rates of decay of {100} steps in LiF surfaces are not limited by diffusion, and transition state theory shows that detachment is rate limiting. The geometry of the LiF study is like that of particle compacts in that facet edges provide sites for nucleation of monolayer ledges at which attachment or detachment can occur; the two models should both be useful in interpreting sintering studies. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Bullard, JW (reprint author), Univ Illinois, Dept Mat Sci & Engn, 1304 W Green St, Urbana, IL 61801 USA. NR 27 TC 5 Z9 5 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD AUG 10 PY 1999 VL 47 IS 10 BP 3057 EP 3061 DI 10.1016/S1359-6454(99)00170-6 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 231DW UT WOS:000082293700019 ER PT J AU Lu, P Loehman, RE Ewsuk, KG Fahrenholtz, WG AF Lu, P Loehman, RE Ewsuk, KG Fahrenholtz, WG TI Transmission electron microscopy study of interfacial microstructure formed by reacting Al-Mg alloy with mullite at high temperature SO ACTA MATERIALIA LA English DT Article DE Al-mullite interaction; transmission electron microscopy (TEM); interface; microstructure; composites ID DIRECTED OXIDATION; METAL PENETRATION; COMPOSITES; ALUMINUM; KINETICS; AL2O3 AB Transmission electron microscopy (TEM) has been used to study the interfacial microstructure formed by reacting Al-Mg alloy with mullite (Al(6)Si(2)O(13)) at high temperature(>900 degrees C). The TEM study was used in order to understand the strong effect of Mg addition on the nature of the reaction between Al and mullite used to form Al/Al(2)O(3) composite. After reaction at 1050 degrees C, the formation of a layered structure between the Al-1% Mg alloy and mullite was observed. An alloy layer with a much higher concentration of Mg than the starting alloy was found present next to the initial mullite surface. Between the alloy layer and mullite, a dense and continuous layer made of small MgAl(2)O(4) (spinel) and Si particles was present. The layer apparently stopped further reaction between Al-Mg alloy and mullite by preventing transport of the metals to the reaction front and the Si reaction product away from the reaction front. The microstructure resulting from the initial reaction indicated the reaction proceeded by replacing Si atoms with Al and Mg atoms on mullite {210} lattice planes and forming MgAl(2)O(4) {311} lattice planes simultaneously. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 New Mexico Inst Min & Technol, Dept Mat Sci & Engn, Socorro, NM 87801 USA. Sandia Natl Labs, Adv Mat Lab, Albuquerque, NM 87185 USA. RP Lu, P (reprint author), New Mexico Inst Min & Technol, Dept Mat Sci & Engn, Socorro, NM 87801 USA. OI Fahrenholtz, William/0000-0002-8497-0092 NR 15 TC 16 Z9 17 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD AUG 10 PY 1999 VL 47 IS 10 BP 3099 EP 3104 DI 10.1016/S1359-6454(99)00176-7 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 231DW UT WOS:000082293700023 ER PT J AU Gilliland, RL Nugent, PE Phillips, MM AF Gilliland, RL Nugent, PE Phillips, MM TI High-redshift supernovae in the Hubble Deep Field SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; methods : numerical; supernovae : general ID STAR-FORMATION HISTORY; LIGHT-CURVE SHAPES; IA SUPERNOVAE; SPACE-TELESCOPE; II SUPERNOVAE; GALAXIES; DISTRIBUTIONS; ULTRAVIOLET; SIGNATURES; PHOTOMETRY AB Two supernovae detected in the Hubble Deep Field (HDF) using the original 1995 December epoch and data from a shorter (63,000 s in F814W) 1997 December visit with HST are discussed. The supernovae (SNe) are both associated with distinct galaxies at redshifts of 0.95 (spectroscopic) from Cohen et al. and 1.32 (photometric) from the work of Fernandez-Solo, Lanzetta, & Yahil. These redshifts are near, in the case of 0.95, and well. beyond, for 1.32, the greatest distance reported previously for SNe. We show that our observations are sensitive to supernovae to z less than or similar to 1.8 in either epoch for an event near peak brightness. Detailed simulations are discussed that quantify the level at which false events from our search phase would start to arise and the completeness-of our search as a function of both SN brightness and host galaxy redshift. The number of Type Ia and Type II SNe expected as a function of redshift in the two HDF epochs are discussed in relation to several published predictions and our own detailed calculations. A mean detection frequency of one SN per epoch for the small HDF area is consistent with expectations from current theory. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Carnegie Inst Washington, Las Campanas Obser, La Serena, Chile. RP Gilliland, RL (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. NR 56 TC 79 Z9 79 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 1999 VL 521 IS 1 BP 30 EP 49 DI 10.1086/307549 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 223YC UT WOS:000081868300003 ER PT J AU Balona, LA Kaye, AB AF Balona, LA Kaye, AB TI Evidence for corotating clouds in the Be star zeta Tauri SO ASTROPHYSICAL JOURNAL LA English DT Article DE line : profiles; stars : early-type; stars : emission-line, Be; stars : individual (zeta Tauri) ID LINE-PROFILE VARIATIONS; MODES AB We reexamine a time series of spectroscopic data of the Be star zeta Tauri obtained by Kaye & Gies. When the difference spectra are folded with the 0.777 day period, a distinctive pattern emerges. This pattern is not the standard "barber pole" diagram expected from nonradial pulsation but is instead a pattern of two sinusoidal variations of enhanced absorption having different amplitudes. We interpret these results as additional evidence for corotating clouds, recently suggested as an explanation of the variations observed in several other Be stars and as indirect evidence for the possible presence of magnetic fields. C1 S African Astron Observ, ZA-7935 W Cape, South Africa. Univ Calif Los Alamos Natl Lab, Div Appl Theoret & Computat Phys, Los Alamos, NM 87545 USA. RP Balona, LA (reprint author), S African Astron Observ, POB 9, ZA-7935 W Cape, South Africa. NR 23 TC 17 Z9 17 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 1999 VL 521 IS 1 BP 407 EP 413 DI 10.1086/307536 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 223YC UT WOS:000081868300038 ER PT J AU Haiman, Z Loeb, A AF Haiman, Z Loeb, A TI X-ray emission from the first quasars SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; cosmology : theory; quasars : general ID HIGH-REDSHIFT GALAXIES; LUMINOSITY FUNCTION; EVOLUTION; UNIVERSE; DENSITY; NUCLEI AB It is currently unknown whether the universe was reionized by quasars or stars at z greater than or similar to 5. We point out that quasars can be best distinguished from stellar systems by their X-ray emission. Based on a simple hierarchical CDM model, we predict the number counts and X-ray fluxes of quasars at high redshifts. The model is consistent with available data on the luminosity function of high-redshift quasars in the optical and soft X-ray bands. The cumulative contribution of faint, undetected quasars in our model is consistent with the unresolved fraction of the X-ray background. We find that the Chandra X-ray Observatory might detect similar to 10(2) quasars from redshifts z greater than or similar to 5 per its 17' x 17' field of view at the flux threshold of similar to 2 x 10(-16) ergs s(-1) cm(-2). The redshifts of these faint point sources could be identified by follow-up infrared observations from the ground or with the Next Generation Space Telescope. C1 NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Haiman, Z (reprint author), NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. NR 29 TC 33 Z9 33 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 10 PY 1999 VL 521 IS 1 BP L9 EP L12 DI 10.1086/312177 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 223YE UT WOS:000081868500003 ER PT J AU Krueger, JK McCrary, BS Wang, AHJ Shriver, JW Trewhella, J Edmondson, SP AF Krueger, JK McCrary, BS Wang, AHJ Shriver, JW Trewhella, J Edmondson, SP TI The solution structure of the Sac7d/DNA complex: A small-angle X-ray scattering study SO BIOCHEMISTRY LA English DT Article ID HYPERTHERMOPHILE SULFOLOBUS-ACIDOCALDARIUS; DNA-BINDING PROTEIN; CRYSTAL-STRUCTURE AB Small-angle X-ray scattering has been used to study the structure of the multimeric complexes that form between double-stranded DNA and the archaeal chromatin protein Sac7d from Sulfolobus acidocaldarius. Scattering data from complexes of Sac7d with a defined 32-mer oligonucleotide, with poly[d(GC)], and with E. coli DNA indicate that the protein binds along the surface of an extended DNA structure. Molecular models of fully saturated Sac7d/DNA complexes were constructed using constraints from crystal structure and solution binding data. Conformational space was searched systematically by varying the parameters of the models within the constrained set to find the best fits between the X-ray scattering data and simulated scattering curves. The best fits were obtained for models composed of repeating segments of B-DNA with sharp kinks at contiguous protein binding sites. The results are consistent with extrapolation of the X-ray crystal structure of a 1:1 Sac7d/octanucleotide complex [Robinson, H., et al, (1998) Nature 392, 202-205] to polymeric DNA. The DNA conformation in our multimeric Sac7d/DNA model has the base pairs tilted by about 35 degrees and displaced 3 Angstrom from the helix axis. There is a large roll between two base pairs at the protein-induced kink site, resulting in an overall bending angle of about 70 degrees for Sac7d binding, Regularly repeating bends in the fully saturated complex result in a zigzag structure with negligible compaction of DNA. The Sac7d molecules in the model form a unique structure with two left-handed helical ribbons winding around the outside of the right-handed duplex DNA. C1 So Illinois Univ, Sch Med, Dept Biochem & Mol Biol, Carbondale, IL 62901 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Univ Illinois, Dept Cell & Struct Biol, Urbana, IL 61801 USA. RP Edmondson, SP (reprint author), So Illinois Univ, Sch Med, Dept Biochem & Mol Biol, Carbondale, IL 62901 USA. RI Krueger, Joanna/A-3110-2011; OI Trewhella, Jill/0000-0002-8555-6766 FU NIGMS NIH HHS [GM 49686] NR 25 TC 24 Z9 27 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD AUG 10 PY 1999 VL 38 IS 32 BP 10247 EP 10255 DI 10.1021/bi990782c PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 226HL UT WOS:000082014500005 PM 10441118 ER PT J AU Huang, K Ghose, R Flanagan, JM Prestegard, JH AF Huang, K Ghose, R Flanagan, JM Prestegard, JH TI Backbone dynamics of the n-terminal domain in E-coli DnaJ determined by N-15- and (CO)-C-13-relaxation measurements SO BIOCHEMISTRY LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; MODEL-FREE APPROACH; SHIFT RELAXATION MECHANISMS; HEAT-SHOCK PROTEINS; MOLECULAR CHAPERONE; ATPASE ACTIVITY; NMR RELAXATION; LONGITUDINAL RELAXATION; CROSS-CORRELATION; STOCHASTIC SIMULATIONS AB The backbone dynamics of the N-terminal domain of the chaperone protein Escherichia coli DnaJ have been investigated using steady-state H-1-N-15 NOEs, N-15 T-1, T-2, and T-1 rho, relaxation times, steady-state C-13(alpha)-(CO)-C-13 NOEs, and (CO)-C-13 T-1 relaxation times. Two recombinant constructs of the N-terminal domain of DnaJ have been studied. One, DnaJ(1-78), contains the most conserved "J-domain" of DnaJ, and the other, DnaJ(1-104), includes a glycine/phenylalanine rich region ("G/F" region) in addition to the "J-domain". DnaJ(1-78) is not capable of stimulating ATP hydrolysis by DnaK, despite the fact that all currently identified sites responsible for DnaJ-DnaK interaction are located in this region. DnaJ(1-104), on the other hand, retains nearly the full ATPase stimulatory activity of full length DnaJ. Recently, a structural analysis of these two molecules was presented in an effort to elucidate the origin of their functional differences [Huang, K,, Flanagan, J. M., and Prestegard, J. H. (1999) Protein Science 8, 203-214]. Herein, an analysis of dynamic properties is presented in a similar effort. A generalized model-free approach with a full treatment of the anisotropic overall rotation of the proteins is used in the analysis of measured relaxation parameters. Our results show that internal motions on pico- to nanosecond time scales in the backbone of DnaJ(1-78) are reduced on the inclusion of the "G/F" region, while conformational exchange on micro- to millisecond time scales increases. We speculate that the enhanced flexibility of residues on the slow time scale upon the inclusion of the "G/F" region could be relevant to the ATPase stimulatory activity of DnaJ if an "induced-fit" mechanism applies to DnaJ-DnaK interactions. C1 Univ Georgia, Complex Carbohydrate Res Ctr, Athens, GA 30602 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Prestegard, JH (reprint author), Univ Georgia, Complex Carbohydrate Res Ctr, 220 Riverbend Rd, Athens, GA 30602 USA. FU NIGMS NIH HHS [R29 GM053181-05, GM 53181] NR 60 TC 24 Z9 26 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD AUG 10 PY 1999 VL 38 IS 32 BP 10567 EP 10577 DI 10.1021/bi990263+ PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 226HL UT WOS:000082014500041 PM 10441154 ER PT J AU Brodsky, SJ Fadin, VS Kim, VT Lipatov, LN Pivovarov, GB AF Brodsky, SJ Fadin, VS Kim, VT Lipatov, LN Pivovarov, GB TI The QCD Pomeron with optimal renormalization SO JETP LETTERS LA English DT Article ID QUANTUM-CHROMODYNAMICS; PERTURBATIVE QCD; COUPLING-CONSTANT; GAUGE-THEORIES; SCHEME; SINGULARITY; MESON AB It is shown that the next-to-leading order (NLO) corrections to the QCD Pomeron intercept obtained from the Balitsky-Fadin-Kuraev-Lipatov (BFKL) equation, when evaluated in non-Abelian physical renormalization schemes with Brodsky-Lepage-Mackenzie (BLM) optimal scale setting, do not exhibit the serious problems encountered in the <(MS)over bar> scheme. A striking feature of the NLO BFKL Pomeron intercept in the BLM approach is that it yields an important approximate conformal invariance. (C) 1999 American Institute of Physics. [S0021-3640(99)00115-2]. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. St Petersburg Nucl Phys Inst, Gatchina 188350, Russia. Int Inst Theoret & Appl Phys, Ames, IA 50011 USA. Russian Acad Sci, Inst Nucl Res, Moscow 117312, Russia. RP Brodsky, SJ (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RI Lipatov, Lev/P-2816-2014; Kim, Victor/L-1648-2013 OI Lipatov, Lev/0000-0001-7786-8818; Kim, Victor/0000-0001-7161-2133 NR 31 TC 181 Z9 181 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-3640 J9 JETP LETT+ JI Jetp Lett. PD AUG 10 PY 1999 VL 70 IS 3 BP 155 EP 160 DI 10.1134/1.568145 PG 6 WC Physics, Multidisciplinary SC Physics GA 234AE UT WOS:000082458700001 ER PT J AU Kerstein, AR AF Kerstein, AR TI One-dimensional turbulence: model formulation and application to homogeneous turbulence, sheer flows, and buoyant stratified flows SO JOURNAL OF FLUID MECHANICS LA English DT Article ID RAYLEIGH-BENARD CONVECTION; 3-DIMENSIONAL VORTICITY EQUATION; DIRECT NUMERICAL-SIMULATION; PLANETARY BOUNDARY-LAYER; NATURAL-CONVECTION; PASSIVE SCALAR; CHANNEL FLOW; TEMPERATURE-FLUCTUATIONS; ISOTROPIC TURBULENCE; THERMAL-CONVECTION C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Kerstein, AR (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. NR 79 TC 123 Z9 130 U1 2 U2 22 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD AUG 10 PY 1999 VL 392 BP 277 EP 334 DI 10.1017/S0022112099005376 PG 58 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 230DF UT WOS:000082236000011 ER PT J AU Lasserre, C Morel, PH Gaudemer, Y Tapponnier, P Ryerson, FJ King, GCP Metivier, F Kasser, M Kashgarian, M Baichi, L Taiya, L Daoyang, Y AF Lasserre, C Morel, PH Gaudemer, Y Tapponnier, P Ryerson, FJ King, GCP Metivier, F Kasser, M Kashgarian, M Baichi, L Taiya, L Daoyang, Y TI Postglacial left slip rate and past occurrence of M >= 8 earthquakes on the western Haiyuan fault, Gansu, China SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SAN-ANDREAS FAULT; QILIAN-SHAN; C-14 DATA; TIBET; TECTONICS; DISPLACEMENT; CALIFORNIA; SUBDUCTION; RECURRENCE; QINGHAI AB High-resolution (HR) air photographs and a 1-m horizontal and 2-m vertical resolution digital elevation model derived from them by stereophotogrammetry provide new constraints on the behavior of the western stretch of the active Haiyuan fault, in Gansu province, China. The photographs cover three swaths along the fault, each about 2-km-long and at least 500-m-wide, near the village of Songshan, at 103.5 degrees E. This high-resolution data set is used to map and measure cumulative horizontal offsets of alluvial terraces and risers that range between 115 and 135 m, and 70 and 90 m, at two sites. Dating these terraces with C-14 yields minimum and maximum ages of 8400 and 7600, and 14,200 years B.P., respectively. This leads to a: postglacial slip rate of 12 +/- 4 mm/yr, with a most likely minimum value of 11.6 +/- 1.1 mm/yr. The smallest stream offsets observed on the HR photographs range between 8 and 16 m and are interpreted as coseismic displacements of the last few earthquakes with M greater than or equal to 8 that ruptured the 220-km-long Tianzhu gap of the fault, west; of the Yellow River. Earthquakes of that size within this gap, which has been quiescent for at least 800 years, would recur at intervals of 1050 +/- 450 years. C1 Inst Phys Globe, CNRS UMR 7578, F-75252 Paris 05, France. Ecole Super Geometres & Topog, F-72000 Le Mans, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. China Seismol Bur, Inst Lanzhou, Seismol Inst, Lanzhou 730000, Peoples R China. RP Lasserre, C (reprint author), Inst Phys Globe, CNRS UMR 7578, 4 Pl Jussieu, F-75252 Paris 05, France. EM lasserre@ipgp.jussieu.fr; gaudemer@ipgp.jussieu.fr; tappon@ipgp.jussieu.fr; ryerson@s91.es.llnl.gov; king@ipgp.jussieu.fr; metivier@ip-gp.jussieu.fr; kasser@esgt.cnam.fr RI Metivier, Francois/B-4202-2011; Kashgarian, Michaele/E-1665-2011; Tapponnier, .Paul/B-7033-2011; Lasserre, Cecile/D-7073-2017; Gaudemer, Yves/K-3921-2012 OI Kashgarian, Michaele/0000-0001-7824-8418; Tapponnier, .Paul/0000-0002-7135-1962; Lasserre, Cecile/0000-0002-0582-0775; NR 37 TC 69 Z9 85 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD AUG 10 PY 1999 VL 104 IS B8 BP 17633 EP 17651 DI 10.1029/1998JB900082 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 224LL UT WOS:000081900500007 ER PT J AU Yu, CH Schafer, L Ramek, M Miller, DM Teppen, BJ AF Yu, CH Schafer, L Ramek, M Miller, DM Teppen, BJ TI Some general aspects of torsional sensitivity and the GG-effect SO JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE GG-effect; torsional sensitivity; conformational geometry functions; structure-conformatic relations; structural gradients ID MOLECULAR CONFORMATIONAL-ANALYSES; GEOMETRY OPTIMIZATION; ABINITIO; ALKANES; ENERGY; AMIDE AB The geometries of 28 compounds of type X-C1-C2-C3-Y, with X, Y = CH(3), F, Cl, OH, NH(2), COH, and COOH, were fully optimized by ab initio HF/4-21G calculations at 30 degrees grid points in their respective phi(X-C1-C2-C3), psi(C1-C2-C3-Y)torsional spaces. The results make it possible to construct parameter surfaces and their gradients in phi, psi-pace. The magnitude of the gradient, \del P\ = [(partial derivative P/partial derivative phi)(2) + (partial derivative P/partial derivative psi)(2)](1/2), of a structural parameter P (a bond length, bond angle, or non-bonded distance) in phi,psi-torsional space is a measure of torsional sensitivity (TS); i.e. a measure of the extent to which bond lengths, bond angles, and non-bonded distances change at a point in phi,psi-space with backbone torsional angles. It is found that TS is not constant throughout the conformational space of a molecule, but varies in a characteristic way. It seems that, regardless of the nature of X or Y, extended forms are typically in regions of low TS; puckered conformations, of high TS. Conformations with two sequential gauche torsional angles (GG sequences) are characterized by high TS of 1,5-non-bonded distances concomitant with relatively low TS of other internal coordinates. This property of GG sequences is the source of a stabilizing and cooperative energy increment that is not afforded by other torsional sequences, such as trans-trans or trans-gauche. A structural data base, consisting of thousands of HF/4-21G structures of X-C-C-Y and X-C-C-C-Y systems has been assembled and is available on a CD. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Arkansas, Dept Chem & Biochem, Fayetteville, AR 72701 USA. Graz Tech Univ, Inst Phys & Theoret Chem, A-8010 Graz, Austria. Univ Arkansas, Dept Agron, Fayetteville, AR 72701 USA. Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Aiken, SC 29802 USA. RP Schafer, L (reprint author), Univ Arkansas, Dept Chem & Biochem, Fayetteville, AR 72701 USA. EM schafer@protein.uark.edu; ramek@ptc.tu-graz.ac.at; dmiller@comp.uark.edu; teppen@srel.edu NR 15 TC 3 Z9 3 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2860 J9 J MOL STRUCT JI J. Mol. Struct. PD AUG 10 PY 1999 VL 485 SI SI BP 373 EP 384 DI 10.1016/S0022-2860(99)00053-8 PG 12 WC Chemistry, Physical SC Chemistry GA 229KE UT WOS:000082193100036 ER PT J AU Melnichenko, YB Kiran, E Wignall, GD Heath, KD Salaniwal, S Cochran, HD Stamm, M AF Melnichenko, YB Kiran, E Wignall, GD Heath, KD Salaniwal, S Cochran, HD Stamm, M TI Pressure- and temperature-induced transitions in solutions of poly(dimethylsiloxane) in supercritical carbon dioxide SO MACROMOLECULES LA English DT Article ID ANGLE NEUTRON-SCATTERING; POLYMER-SOLUTIONS; CONCENTRATION DIAGRAM; POLYSTYRENE; CROSSOVER AB Supercritical fluids (SCFs) have great technological potential for minimizing the organic wastes associated with polymer manufacturing and processing. However, significant challenges remain for developing the same level of understanding of the behavior of polymers in SCFs as has been reached for polymers in traditional organic solvents. Small-angle neutron scattering was used to study the effect of pressure and temperature on the phase behavior of poly(dimethylsiloxane) (PDMS) in supercritical carbon dioxide (SC CO2). It was demonstrated that PDMS-SC CO2 solutions reproduce all main features of the temperature-concentration phase diagram for polymers in organic solvents. Moreover, because of their continuously adjustable solubility, SCFs exhibit novel effects, such as a pressure-induced transition to the Theta point and to the good solvent domain, in addition to a polymer-solvent demixing at a lower critical solution pressure. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Maine, Dept Chem Engn, Orono, ME 04469 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Max Planck Inst Polymerforsch, D-55021 Mainz, Germany. RP Melnichenko, YB (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 21 TC 51 Z9 51 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 10 PY 1999 VL 32 IS 16 BP 5344 EP 5347 DI 10.1021/ma990640q PG 4 WC Polymer Science SC Polymer Science GA 227BL UT WOS:000082058100027 ER PT J AU Vergara, G Herrera-Gomez, A Spicer, WE AF Vergara, G Herrera-Gomez, A Spicer, WE TI Calculated electron energy distribution of negative electron affinity cathodes SO SURFACE SCIENCE LA English DT Article DE affinity; barrier; cesium; distribution; energy; photoemission; potential; surface ID GALLIUM-ARSENIDE; PHOTOCATHODES; LAYER AB In this paper we present a model whose purpose was to study the electron energy distribution curves (EDC) of high efficiency negative electron affinity (NEA) GaAs photocathodes and to explain the features of earlier experimental data. The EDCs were calculated for transmission mode cathodes using the Monte Carlo method. The influence of parameters such as the surface potential barrier shape, p-doping concentration, vacuum level (VL), and temperature on the EDC broadening was studied. Using our model, we found that the experimental electron energy spread could be explained by the extra time the electrons spend inside the semiconductor due to multiple bouncing at the surface before escaping. There is no need to invoke electron interaction with surface trapping states. The difference between the effective electron mass in the semiconductor and the mass in the vacuum causes a refraction effect that narrows the escape angle around the surface normal. In accordance with the dipole model for NEA, the surface barrier was modeled in two sections: a triangular barrier at the surface and a flat plateau outside the semiconductor at the vacuum level. The magnitude of the energy distribution width of the experimental data studied indicates that the electrons spend a long time in the band bending region before escaping, which in turn indicates that the electrons are quantum reflected at the surface barrier a number of times before their final escape. This barrier is very sensitive to surface preparation details. The experimental data indicates that, for the high yield cathode considered, the vacuum level lies similar to 0.1 eV below the bulk conduction band minimum and that the modeled triangular potential at the surface barrier was approximately 1.5 Angstrom thick and 4 eV high. In the case of this barrier, the escape probability for electrons hitting the surface with energy between the vacuum level and 0.2 eV above was smaller than 0.2. (C) 1999 Elsevier Science B.V, All rights reserved. C1 Stanford Elect Labs, Stanford, CA 94305 USA. UAQ, CINVESTAV, Lab Invest Mat, Queretaro 76010, Mexico. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. CIDA, Madrid 28033, Spain. RP Herrera-Gomez, A (reprint author), CMR Press Warehouse, 435 Santa Teresa, Stanford, CA 94305 USA. RI Vergara Ogando, German/B-9706-2015 OI Vergara Ogando, German/0000-0002-9406-1335 NR 14 TC 23 Z9 23 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 10 PY 1999 VL 436 IS 1-3 BP 83 EP 90 DI 10.1016/S0039-6028(99)00612-3 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 233ZC UT WOS:000082456200026 ER PT J AU Hay, PJ Boehm, RC Kress, JD Martin, RL AF Hay, PJ Boehm, RC Kress, JD Martin, RL TI Theoretical studies of H-2 desorption processes in chemical vapor deposition of boron-doped silicon surfaces SO SURFACE SCIENCE LA English DT Article DE ab initio quantum chemical methods and calculations; boron; density functional calculations; hydrogen; models of surface chemical reactions; silicon; surface chemical reaction ID TEMPERATURE-PROGRAMMED DESORPTION; HYDROGEN DESORPTION; MOLECULAR-HYDROGEN; DIHYDRIDE SI(100); ADSORPTION; DYNAMICS; KINETICS; PATHWAY; GROWTH; SI AB The desorption of hydrogen in the chemical vapor deposition (CVD) of boron-doped silicon (100) surfaces is investigated using density functional theory and cluster models. The cluster models examine reactions of hydrogen atoms bound to adjacent B-Si surface sites that would arise during the decomposition of B2H6 and SiH4 on a B-doped polysilicon film that is being formed by CVD. Comparisons are made with the analogous processes involving desorption of H-2 from Si dimers, as well as with previous studies in the literature. Calculations show a barrier of approximately 25 kcal/mol for desorption of H-2 from Si8BH14 ('HB -SiH') and Si8BH15 ('HB-SiH2') clusters. These calculated barriers may be compared to values of(a) 75-85 kcal/mol typically obtained from other cluster calculations for 'prepairing' and 'isomerization pathways' from Si dimers on the surface; (b) 53-58 kcal/mol for desorption from SiH2 'defects'; and (c) 55-60 kcal/mol from two-dimensional periodic slab calculations of hydrogen desorption from Si surfaces. These results indicate that barriers for desorption of H-2 from B-Si-containing surface dimers are lower than desorption of H-2 from Si surface dimers. These lower barriers arise in part because the hydrogen bound to the B surface atom involves four-coordinate B species which have lower bond energies than classical B-H or Si-H bonds. These lower barriers could play a role in explaining the increased growth rate of Si observed when chemical vapor deposition is carried out using both SiH4 (or SiCl2H2) and B2H6 precursors. Finally we examined briefly the role of subsurface B atoms in the desorption of hydrogen from Si surfaces, as occurs in desorption studies on annealed B-doped Si films. Small lowerings in the hydrogen desorption energy (from 54 to 52 kcal/mol) and activation barrier (from 76 to similar to 70 kcal/mol) were found due to the effect of subsurface B atoms in Si clusters. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. New Mexico Highlands Univ, Sch Nat Sci, Las Vegas, NM 87701 USA. RP Hay, PJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, MS B268, Los Alamos, NM 87545 USA. NR 51 TC 12 Z9 13 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 10 PY 1999 VL 436 IS 1-3 BP 175 EP 192 DI 10.1016/S0039-6028(99)00661-5 PG 18 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 233ZC UT WOS:000082456200036 ER PT J AU Jirsak, T Dvorak, J Rodriguez, JA AF Jirsak, T Dvorak, J Rodriguez, JA TI Adsorption of NO2 on Rh(111) and Pd/Rh(111): photoemission studies SO SURFACE SCIENCE LA English DT Article DE bimetallic surfaces; catalysis; chemisorption; low index single crystal surfaces; nitric oxide; nitrogen dioxide; palladium; rhodium; spillover; synchrotron radiation photoelectron spectroscopy ID NITROGEN-DIOXIDE; NITRIC-OXIDE; MOLECULAR ADSORPTION; PD(111) SURFACE; DESORPTION; OXYGEN; PD; DISSOCIATION; KINETICS; XPS AB Synchrotron-based high-resolution photoemission has been used to study the interaction of NO2 with Rh(111) and Pd/Rh(111) surfaces. Clean Rh(111) reacts readily with nitrogen dioxide which decomposes at temperatures less than or equal to 150 K producing adsorbed NO and oxygen adatoms (NO2-->NOa + O-a). The majority of the adsorbed NO further dissociates (NOa-->N-a + O-a) between 300 and 400 K. The bimetallic Pd/Rh(111) system exhibits a significantly lower reactivity towards NO2 in comparison with Pd(111) and Rh(111). On Pd/Rh(111) surfaces (theta(Pd) =0.6-1.2 ML), NO2 dissociates at low temperatures, but essentially no decomposition to atomic nitrogen occurs and all the nitrogen molecular species disappear from the surface by 380 K. The O-Pd bond in a Pd-1.2/Rh(111) system is substantially weaker (adsorption energy lowered by at least 20 kcal mol(-1)) than on the individual metals and most of the oxygen evolves from the surface by 400 K. When the Rh(111) surface is only partially covered with Pd (Pd-0.6/Rh(111)), spillover of adsorbed species from Pd islands to the bare Rh(111) patches is observed when the temperature of the system is increased from 100 to 400 K. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 33 TC 47 Z9 48 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 10 PY 1999 VL 436 IS 1-3 BP L683 EP L690 DI 10.1016/S0039-6028(99)00656-1 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 233ZC UT WOS:000082456200009 ER PT J AU Wang, CZ Pan, BC Xiang, JB Ho, KM AF Wang, CZ Pan, BC Xiang, JB Ho, KM TI Adatom vacancies on the Si(111)-(7 x 7) surface SO SURFACE SCIENCE LA English DT Article DE field evaporation; semi-empirical models and model calculations; silicon; surface defects; surface energy ID ENERGY; RECONSTRUCTION; SYSTEMS AB The structures, energies and electronic properties of the adatom vacancies on the Si(111)-(7 x 7) surface are studied by tight-binding molecular dynamics calculations using the recently developed environment-dependent potential of silicon. Adatom vacancies on the edge of the (7 x 7) unit cell are found to have formation energies lower than those on the corner of the unit cell by about 0.1 eV. Structure relaxation induced by the vacancies is found to be significant. Localized electronic states associated with the vacancies are also observed at energy about 0.5 eV below the Fermi energy level. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. RP Wang, CZ (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 11 TC 8 Z9 9 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 10 PY 1999 VL 436 IS 1-3 BP L697 EP L701 DI 10.1016/S0039-6028(99)00695-0 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 233ZC UT WOS:000082456200011 ER PT J AU Gousev, YP Altukhov, IV Korolev, KA Sinis, VP Kagan, MS Haller, EE Odnoblyudov, MA Yassievich, IN Chao, KA AF Gousev, YP Altukhov, IV Korolev, KA Sinis, VP Kagan, MS Haller, EE Odnoblyudov, MA Yassievich, IN Chao, KA TI Widely tunable continuous-wave THz laser SO APPLIED PHYSICS LETTERS LA English DT Article ID P-GE; RADIATION; SPECTROSCOPY; DETECTOR; PULSES; MIXER AB We present experimental results on continuous-wave generation of THz radiation by strained Ge and a theoretical model for population inversion of carriers giving rise to the stimulated THz emission. Resonant acceptor states induced by strain and resonance hole scattering under applied electric field are necessary for the inversion. (C) 1999 American Institute of Physics. [S0003-6951(99)02132-4]. C1 Royal Inst Technol, Dept Elect, S-16440 Kista, Sweden. Russian Acad Sci, Inst Radioengn & Elect, Moscow 103907, Russia. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Lund, Dept Theoret Phys, S-22362 Lund, Sweden. RP Gousev, YP (reprint author), Royal Inst Technol, Dept Elect, S-16440 Kista, Sweden. NR 21 TC 68 Z9 71 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 9 PY 1999 VL 75 IS 6 BP 757 EP 759 DI 10.1063/1.124503 PG 3 WC Physics, Applied SC Physics GA 222FJ UT WOS:000081772600005 ER PT J AU Baker, KL Porter, JL Ruggles, LE Chandler, GA Deeney, C Vargas, M Moats, A Struve, K Torres, J McGurn, J Simpson, WW Fehl, DL Chrien, RE Matuska, W Idzorek, GC AF Baker, KL Porter, JL Ruggles, LE Chandler, GA Deeney, C Vargas, M Moats, A Struve, K Torres, J McGurn, J Simpson, WW Fehl, DL Chrien, RE Matuska, W Idzorek, GC TI Soft x-ray measurements of z-pinch-driven vacuum hohlraums SO APPLIED PHYSICS LETTERS LA English DT Article ID INERTIAL CONFINEMENT FUSION; HIGH-TEMPERATURES; WIRE; RADIATION; SYMMETRY; POWER AB This letter reports the experimental characterization of a z-pinch-driven vacuum hohlraum. We have measured soft x-ray fluxes of 5x10(12) W/cm(2) radiating from the walls of hohlraums which are 2.4-2.5 cm in diameter by 1 cm tall. The x-ray source used to drive these hohlraums was a z pinch consisting of a 300 wire tungsten array driven by a 20 MA, 100 ns current pulse. In this hohlraum geometry, the z-pinch x-ray source can produce energies in excess of 800 kJ and powers in excess of 100 TW to drive these hohlraums. The x rays released in these hohlraums represent greater than a factor of 25 in energy and more than a factor of 3 in x-ray power over previous laboratory-driven hohlraums. (C) 1999 American Institute of Physics. [S0003-6951(99)02732-1]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Baker, KL (reprint author), Univ Calif Davis, Livermore, CA 94551 USA. NR 14 TC 21 Z9 21 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 9 PY 1999 VL 75 IS 6 BP 775 EP 777 DI 10.1063/1.124509 PG 3 WC Physics, Applied SC Physics GA 222FJ UT WOS:000081772600011 ER PT J AU Campbell, IH Smith, DL Neef, CJ Ferraris, JP AF Campbell, IH Smith, DL Neef, CJ Ferraris, JP TI Charge transport in polymer light-emitting diodes at high current density SO APPLIED PHYSICS LETTERS LA English DT Article ID INJECTION AB We present measured and calculated current-voltage (I-V) characteristics of diodes fabricated using a soluble poly(p-phenylene vinylene) derivative. Steady-state and pulsed electrical excitation were used to acquire the I-V characteristics for current densities from 1x10(-3) to 1.3x10(3) A/cm(2). Hole current is predominant in the diode. The I-V characteristics were fit using a device model that assumes an electric field-dependent hole mobility of the Poole-Frenkel form that is independent of the charge carrier density. The measured and calculated I-V characteristics are in good agreement over the full range of current density. The maximum electric field and carrier density is about 4x10(6) V/cm and 1x10(18) cm(-3), respectively. These results demonstrate that an electric field-dependent mobility, without carrier density dependence, provides an accurate description of hole transport in this polymer over this range of field and carrier density. (C) 1999 American Institute of Physics. [S0003-6951(99)04532-5]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Texas, Richardson, TX 75083 USA. RP Campbell, IH (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 17 TC 39 Z9 39 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 9 PY 1999 VL 75 IS 6 BP 841 EP 843 DI 10.1063/1.124531 PG 3 WC Physics, Applied SC Physics GA 222FJ UT WOS:000081772600033 ER PT J AU Davis, MI Wasinger, EC Westre, TE Zaleski, JM Orville, AM Lipscomb, JD Hedman, B Hodgson, KO Solomon, EI AF Davis, MI Wasinger, EC Westre, TE Zaleski, JM Orville, AM Lipscomb, JD Hedman, B Hodgson, KO Solomon, EI TI Spectroscopic investigation of reduced protocatechuate 3,4-dioxygenase: Charge-induced alterations in the active site iron coordination environment SO INORGANIC CHEMISTRY LA English DT Article ID MAGNETIC CIRCULAR-DICHROISM; X-RAY-ABSORPTION; CRYSTAL-STRUCTURE; BREVIBACTERIUM-FUSCUM; ELECTRONIC-STRUCTURE; SUBSTRATE-BINDING; EXTRADIOL DIOXYGENASES; PSEUDOMONAS-AERUGINOSA; MODEL COMPLEXES; LIGAND-BINDING AB Chemical reduction of the mononuclear ferric active site in the bacterial intradiol cleaving catecholic dioxygenase protocatechuate 3,4-dioxygenase (3,4-PCD, Brevibacterium fuscum) produces a high-spin ferrous center. We have applied circular dichroism (CD), magnetic circular dichroism (MCD), variable-temperature-variable-field (VTVH) MCD, X-ray absorption (XAS) pre-edge, and extended X-ray absorption fine structure (EXAFS) spectroscopies to investigate the geometric and electronic structure of the reduced iron center. Excited-state ligand field CD and MCD data indicate that the site is six-coordinate where the E-5(g) excited-state splitting is 2033 cm(-1), VTVH MCD analysis of the ground state indicates that the site has negative zero-field splitting with a small rhombic splitting of the lowest doublet (delta = 1.6 +/- 0.3 cm(-1)). XAS pre-edge analysis also indicates a six-coordinate site while EXAFS analysis provides accurate bond lengths. Since previous spectroscopic analysis and the crystal structure of oxidized 3,4-PCD indicate a five-coordinate ferric active site, the results presented here show that the coordination number increases upon reduction. This is attributed to the coordination of a second solvent ligand. The coordination number increase relative to the oxidized site also appears to be associated with a large decrease in the ligand donor strength in the reduced enzyme due to protonation of the original hydroxide ligand. C1 Univ Minnesota, Dept Biochem, Minneapolis, MN 55455 USA. Univ Minnesota, Ctr Met Biocatalysis, Minneapolis, MN 55455 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Lipscomb, JD (reprint author), Univ Minnesota, Dept Biochem, Minneapolis, MN 55455 USA. OI Lipscomb, John/0000-0002-8158-5594 FU NIGMS NIH HHS [R01 GM024689, R37 GM024689] NR 55 TC 15 Z9 15 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD AUG 9 PY 1999 VL 38 IS 16 BP 3676 EP 3683 DI 10.1021/ic981464p PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 226JV UT WOS:000082017600015 PM 11671125 ER PT J AU Paine, RT Koestle, W Borek, TT Wood, GL Pruss, EA Duesler, EN Hiskey, MA AF Paine, RT Koestle, W Borek, TT Wood, GL Pruss, EA Duesler, EN Hiskey, MA TI Synthesis, characterization, and explosive properties of the nitrogen-rich borazine [H3N3B3(N-3)(3)] SO INORGANIC CHEMISTRY LA English DT Article ID THERMAL-DECOMPOSITION; CRYSTAL-STRUCTURE; BORON IMIDES; AZIDES; IMINOBORANES AB The azidoborazines [Me3N3B2(Me)(2)B(N-3)] and [H3N3B3(N-3)(3)] were prepared from the combination of Me3SiN3 and the chloroborazines [Me3N3B2(Me)(2)BCl] and (H3N3B3Cl3). The compounds have been characterized by analytical and spectroscopic methods. The molecular structure of [H3N3B3(N-3)(3)] has been confirmed by single-crystal X-ray diffraction techniques: triclinic space group P (1) over bar with a = 8.579(1) Angstrom, b = 9.182(1) Angstrom, c = 12.043(1) Angstrom, alpha = 104.62(1)degrees, beta = 90.26(1)degrees, gamma = 110.74(1)degrees, and Z = 4. The thermal behavior of the azides have been examined by TGA/DTA. The explosion sensitivity of [H3N3B3(N-3)(3)], which contains 82.58% nitrogen by weight, has been accessed by drop weight impact, spark, and friction tests. These measurements indicate that [H3N3B3(N-3)(3)] is a relatively sensitive explosive. The Staudinger reactivity of the azides with Ph3P was examined, and [H3N3B3(N-3)(3)] was found to produce [Ph3P=NH2](N-3). The molecular structure of this compound was determined by single-crystal X-ray diffraction techniques: orthorhombic space group P2(1)2(1)2(1) with a = 10.649(2) Angstrom, b = 11.737(3) Angstrom, c = 13.364(4) Angstrom, alpha = beta = gamma = 90 degrees, Z = 4. C1 Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Univ Calif Los Alamos Natl Lab, Grp DX2, Los Alamos, NM 87545 USA. RP Paine, RT (reprint author), Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. NR 41 TC 27 Z9 29 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD AUG 9 PY 1999 VL 38 IS 16 BP 3738 EP 3743 DI 10.1021/ic990316b PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 226JV UT WOS:000082017600026 ER PT J AU Chiu, SW Cheung, YS Ma, NL Li, WK Ng, CY AF Chiu, SW Cheung, YS Ma, NL Li, WK Ng, CY TI A Gaussian-2 ab initio study of [C2H5S](+) ions: II. fragmentation and CH3SCH2+ and CH2CHSH2+ revisited SO JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM LA English DT Article DE Gaussian-2 theory; [C2H5S](+) ions; unimolecular dissociations; ion-molecule complexes; ion-radical complexes ID DIMER RADICAL CATION; GAS-PHASE; NEUTRAL COMPLEXES; MASS-SPECTROMETRY; UNIMOLECULAR DECOMPOSITIONS; ELECTRON PHOTODETACHMENT; VIBRATIONAL FREQUENCIES; PHOTO-IONIZATION; C2H3S+ IONS; ENERGIES AB Gaussian-2 ab initio method was performed to examine the five modes of unimolecular dissociation of CH3SCH2+ (1(+)) and CH2CHSH2+ (5(+)): 1(+) --> CH3 + H2CS+ (1); 1(+) --> CH + H2CS (2); 1(+) --> CH4 + HCS+ (3); 5(+) --> H2S + [C2H3](+) (4); and 5(+) --> H3S+ + C2H2 (5). Both reactions 1 and 2, with endothermicities 359 and 395 kJ mol(-1) respectively, proceed without a reverse barrier. Loss of CH4 from 1(+) (reaction 3) proceeds via a transition state resembling an ion-radical complex CH3/ H2CS+. The elimination reaction has an energy barrier of 332 kJ mol(-1). Loss of H2S from 5(+) (reaction 4) initially proceeds through either cleavage of the C-S bond or formation of the ion-molecule complex H2S/[C2H3](+) (8(+)/9(+)), followed by dissociation of the complex. The endothermicity of reaction 3 is calculated to be 245-261 kJ mol(-1). Reaction 5, the lowest energy process among the dissociation pathways studied in this work, proceeds via intermediates 9(+) and H3S+/C2H2 (10(+)). Its rate-determining step 5(+) --> 9(+) has an energy barrier of 220 kJ mol(-1). (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Illinois, Natl Ctr Supercomp Applicat, Urbana, IL 61801 USA. Univ Illinois, Dept Mol & Integrat Physiol, Urbana, IL 61801 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Natl Univ Singapore, Dept Chem, Singapore 119260, Singapore. Chinese Univ Hong Kong, Dept Chem, Hong Kong, Peoples R China. RP Chiu, SW (reprint author), Univ Illinois, Natl Ctr Supercomp Applicat, Urbana, IL 61801 USA. NR 64 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 J MOL STRUC-THEOCHEM JI Theochem-J. Mol. Struct. PD AUG 9 PY 1999 VL 468 IS 1-2 BP 21 EP 37 PG 17 WC Chemistry, Physical SC Chemistry GA 226LG UT WOS:000082021000003 ER PT J AU Ding, WJ Fang, DC AF Ding, WJ Fang, DC TI DFT and topological study on the mechanism of ring opening of cyclobutenone, azetinone and oxetone SO JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM LA English DT Article DE ab initio MO and density functional calculations; ring opening reaction mechanism; Bader type topological analysis ID CHARGE-DENSITY; NUCLEOPHILIC-ADDITION; REACTIVITY; ATOMS; BONDS; PREDICTIONS; MOLECULES; LAPLACIAN AB Ab initio MO (HF/6-31G**) and density functional (B3LYP/6-31 + + G**) methods have been used to study the mechanisms of ring opening reactions of cyclobutenone, azetinone and oxetone. Structures of the stationary points on the three reaction potential energy surfaces have been located at both HF/6-31G** and B3LYP/6-31 + +G** levels. In addition,, we have also calculated the topological properties of all stationary points using AIMPC98, a PC version of AIMPAC program, based on B3LYP/6-31++G** wavefunctions. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Beijing Normal Univ, Dept Chem, Beijing 100875, Peoples R China. RP Fang, DC (reprint author), Argonne Natl Lab, CHM 200, Argonne, IL 60439 USA. NR 21 TC 2 Z9 2 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 J MOL STRUC-THEOCHEM JI Theochem-J. Mol. Struct. PD AUG 9 PY 1999 VL 468 IS 1-2 BP 119 EP 125 PG 7 WC Chemistry, Physical SC Chemistry GA 226LG UT WOS:000082021000012 ER PT J AU Chung, SU AF Chung, SU TI New results on exotic mesons from BNL-E852 SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 5th Biennial Conference on Low Energy Antiproton Physics (LEAP98) CY SEP 07-12, 1998 CL VILLASIMIUS, ITALY SP INFN, Univ Cagliari ID 18 GEV/C; SYSTEM AB We have so far found evidence for two exotic mesons with the quantum numbers I-G J(PC) = 1(-)1(-+) at masses 1.4 and 1.6 GeV. They are seen in the decay channels pi eta, pi rho and pi eta' With varying degrees of strengths. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Chung, SU (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 38 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD AUG 9 PY 1999 VL 655 IS 1-2 BP 77C EP 81C DI 10.1016/S0375-9474(99)00183-9 PG 5 WC Physics, Nuclear SC Physics GA 234TR UT WOS:000082500900012 ER PT J AU LeFort, T Kwiatkowski, K Hsi, WC Beaulieu, L Viola, VE Pienkowski, L Korteling, RG Leforest, R Martin, E Ramakrishnan, E Rowland, D Ruangma, A Winchester, E Yennello, SJ Gushue, S Remsberg, LP Back, B Breuer, H AF LeFort, T Kwiatkowski, K Hsi, WC Beaulieu, L Viola, VE Pienkowski, L Korteling, RG Leforest, R Martin, E Ramakrishnan, E Rowland, D Ruangma, A Winchester, E Yennello, SJ Gushue, S Remsberg, LP Back, B Breuer, H TI Heating nuclei with 8 GeV/c antiprotons SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 5th Biennial Conference on Low Energy Antiproton Physics (LEAP98) CY SEP 07-12, 1998 CL VILLASIMIUS, ITALY SP INFN, Univ Cagliari ID AU-197 REACTIONS; HOT NUCLEI; BEAMS; 4-PI AB Studies of the heating effect of 8 GeV/c pi(-) and antiproton beams incident on a Au-197 nucleus have been conducted at Brookhaven AGS accelerator with the Indiana Silicon Sphere 4 pi detector array. Enhanced energy deposition for antiprotons relative to negative pions and protons in this energy regime is observed. The results are consistent with predictions of an intranuclear cascade code. C1 Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. Indiana Univ, IUCF, Bloomington, IN 47405 USA. Warsaw Univ, Dept Chem, Warsaw, Poland. Simon Fraser Univ, Dept Chem, Burnaby, BC V5A 1S6, Canada. Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA. Texas A&M Univ, Cyclotron Lab, College Stn, TX 77843 USA. Brookhaven Natl Lab, Div Phys, Upton, NY 11973 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RP Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. RI Rowland, Douglas/F-3104-2014; Yennello, Sherry/B-5803-2015 OI Rowland, Douglas/0000-0001-8059-6905; Yennello, Sherry/0000-0003-3963-5217 NR 15 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD AUG 9 PY 1999 VL 655 IS 1-2 BP 275C EP 280C DI 10.1016/S0375-9474(99)00213-4 PG 6 WC Physics, Nuclear SC Physics GA 234TR UT WOS:000082500900041 ER PT J AU Holzscheiter, MH AF Holzscheiter, MH CA ATHENA Collaboration TI Formation of low-energy antihydrogen SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 5th Biennial Conference on Low Energy Antiproton Physics (LEAP98) CY SEP 07-12, 1998 CL VILLASIMIUS, ITALY SP INFN, Univ Cagliari ID PENNING TRAPS; TESTING CPT; ANTIPROTONS; COLLISIONS; POSITRONIUM; PLASMAS AB Antihydrogen atoms, produced near rest, trapped in a magnetic well, and cooled to the lowest possible temperature (kinetic energy) could provide an extremely powerful tool for the search of violations of CPT and Lorentz invariant. We describe our plans to trap antiprotons and positrons in a combined Penning trap and to form a significant number of cold antihydrogen atoms for comparative precision spectroscopy of hydrogen and antihydrogen. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Holzscheiter, MH (reprint author), Univ Calif Los Alamos Natl Lab, P-23,MS H803, Los Alamos, NM 87544 USA. NR 42 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD AUG 9 PY 1999 VL 655 IS 1-2 BP 363C EP 368C DI 10.1016/S0375-9474(99)00225-0 PG 6 WC Physics, Nuclear SC Physics GA 234TR UT WOS:000082500900053 ER PT J AU Chalmers, G Schalm, K AF Chalmers, G Schalm, K TI The large N-c limit of four-point functions in N=4 super-Yang-Mills theory from anti-de Sitter supergravity SO NUCLEAR PHYSICS B LA English DT Article DE AdS/QFT correspondence; large-N gauge theories; supergravity ID LOOP FEYNMAN DIAGRAMS; ALGEBRAIC REDUCTION; THEORY CORRELATORS; SCALAR INTEGRALS; FIELD-THEORY; SPACE; AMPLITUDES; STATES AB We compute the imaginary part of scalar four-point functions in the AdS/CFT correspondence relevant to N = 4 super Yang-Mills theory. Unitarity of the AdS supergravity demands that the imaginary parts of the correlation functions factorize into products of lower-point functions, We include the exchange diagrams for scalars as well as gravitons and find explicit expressions for the imaginary parts of these correlators. In momentum space these expressions contain only rational functions and logarithms of the kinematic invariants, in such a manner that the correlator is not a free-field result, The simplicity of these results, however, indicate the possibility of additional symmetry structures in N = 4 super Yang-Mills theory in the large N, limit at strong effective coupling. The complete expressions may be computed from the integral results derived here. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. SUNY Stony Brook, Inst Theoret Phys, Stony Brook, NY 11794 USA. RP Chalmers, G (reprint author), Argonne Natl Lab, Div High Energy Phys, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 49 TC 22 Z9 22 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD AUG 9 PY 1999 VL 554 IS 1-2 BP 215 EP 236 DI 10.1016/S0550-3213(99)00275-8 PG 22 WC Physics, Particles & Fields SC Physics GA 226LR UT WOS:000082021900010 ER PT J AU He, XG Hou, WS Yang, KC AF He, XG Hou, WS Yang, KC TI Indications for factorization and ReVub < 0 from rare B decay data SO PHYSICAL REVIEW LETTERS LA English DT Article AB Surveying known hadronic rare B decays, we find that the factorization approximation can give a coherent account of K pi, pi pi, and rho(0)pi(+) data and give predictions for omega(0)pi(+), rho pi, and K*pi modes, if ReVuh is taken as negative (in standard phase convention) rather than positive. As further confirmation, we expect a lower sin2 beta value at B factories as compared to current fits, and B-s mixing close to LEP bounds at SLD and CDF. C1 Natl Taiwan Univ, Dept Phys, Taipei 10764, Taiwan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Acad Sinica, Inst Phys, Taipei, Taiwan. RP He, XG (reprint author), Natl Taiwan Univ, Dept Phys, Taipei 10764, Taiwan. RI He, Xiao-Gang/C-8894-2013; He, Xiao-Gang/P-2242-2015 NR 21 TC 48 Z9 48 U1 0 U2 1 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 AUG 9 PY 1999 VL 83 IS 6 BP 1100 EP 1103 DI 10.1103/PhysRevLett.83.1100 PG 4 WC Physics, Multidisciplinary SC Physics GA 223ZL UT WOS:000081871400006 ER PT J AU Ninov, V Gregorich, KE Loveland, W Ghiorso, A Hoffman, DC Lee, DM Nitsche, H Swiatecki, WJ Kirbach, UW Laue, CA Adams, JL Patin, JB Shaughnessy, DA Strellis, DA Wilk, PA AF Ninov, V Gregorich, KE Loveland, W Ghiorso, A Hoffman, DC Lee, DM Nitsche, H Swiatecki, WJ Kirbach, UW Laue, CA Adams, JL Patin, JB Shaughnessy, DA Strellis, DA Wilk, PA TI Observation of superheavy nuclei produced in the reaction of Kr-86 with Pb-208 SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELEMENTS; DECAY; RANGE; IONS AB Following a prediction by Smolanczuk [Phys. Rev. C 59, 2634 (1999)], we searched for superheavy element formation in the bombardment of Pb-208 With 449-Mev Kr-86 ions. We have observed three decay chains, each consisting of an implanted heavy atom and six subsequent alpha decays, correlated in time and position. In these decay chains, a rapid (ms) sequence of high energy alpha particles (E-alpha greater than or equal to 10 MeV) indicates the decay of a new high-Z element. The observed chains are consistent with the formation of (293)118 and its decay by sequential alpha-particle emission to (289)116, (285)114, (281)112, (277)110, (273)Hs (Z = 108) and (269)Sg (Z = 106). The production cross section is 2.2(-0.8)(+2.6) pb. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Oregon State Univ, Dept Chem, Corvallis, OR 97331 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Ninov, V (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Wilk, Philip/B-5954-2008 NR 24 TC 173 Z9 176 U1 0 U2 6 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 AUG 9 PY 1999 VL 83 IS 6 BP 1104 EP 1107 DI 10.1103/PhysRevLett.83.1104 PG 4 WC Physics, Multidisciplinary SC Physics GA 223ZL UT WOS:000081871400007 ER PT J AU Cwiok, S Nazarewicz, W Heenen, PH AF Cwiok, S Nazarewicz, W Heenen, PH TI Structure of odd-N superheavy elements SO PHYSICAL REVIEW LETTERS LA English DT Article ID SHELL STRUCTURE; NUCLEI; HEAVY AB Structure of the odd-N superheavy elements with Z less than or similar to 118 and N less than or equal to 175 is investigated using the self-consistent Skyrme-Hartree-Fock-Bogoliubov method with pairing. Microscopic analysis of one-quasiparticle neutron states, alpha-decay energies, and deformations is performed. Good agreement was obtained with the recently reported alpha-decay chains of (289)114 and (293)118. C1 Warsaw Univ Technol, Inst Phys, PL-00662 Warsaw, Poland. Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Warsaw, Inst Theoret Phys, PL-00681 Warsaw, Poland. Free Univ Brussels, Serv Phys Nucl Theor, B-1050 Brussels, Belgium. RP Warsaw Univ Technol, Inst Phys, Ul Koszykowa 75, PL-00662 Warsaw, Poland. NR 31 TC 176 Z9 178 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 9 PY 1999 VL 83 IS 6 BP 1108 EP 1111 DI 10.1103/PhysRevLett.83.1108 PG 4 WC Physics, Multidisciplinary SC Physics GA 223ZL UT WOS:000081871400008 ER PT J AU Sonzogni, AA Davids, CN Woods, PJ Seweryniak, D Carpenter, MP Ressler, JJ Schwartz, J Uusitalo, J Walters, WB AF Sonzogni, AA Davids, CN Woods, PJ Seweryniak, D Carpenter, MP Ressler, JJ Schwartz, J Uusitalo, J Walters, WB TI Fine structure in the decay of the highly deformed proton emitter Eu-131 SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUCLEI; RADIOACTIVITY AB Fine structure in the ground-state proton radioactive decay of highly deformed Eu-131 has been identified. In addition to the previously observed ground-state line, measured here with a proton energy of 932(7) keV, a second proton peak with energy 811(7) keV was observed. We interpret this line as proton decay from the Eu-131 ground state to the first excited 2(+) state of the daughter nucleus Sm-130. Comparing the measured branching ratio with calculations enables the ground-state configuration of Eu-131 to be unambiguously assigned to the 3/2(+)[411] Nilsson configuration. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Edinburgh, Edinburgh EH9 3JZ, Midlothian, Scotland. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Yale Univ, Dept Phys, New Haven, CT 06511 USA. RP Sonzogni, AA (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RI Ressler, Jennifer Jo/F-2279-2010; Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 15 TC 94 Z9 97 U1 2 U2 5 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 AUG 9 PY 1999 VL 83 IS 6 BP 1116 EP 1118 DI 10.1103/PhysRevLett.83.1116 PG 3 WC Physics, Multidisciplinary SC Physics GA 223ZL UT WOS:000081871400010 ER PT J AU Czarnecki, A Melnikov, K Yelkhovsky, P AF Czarnecki, A Melnikov, K Yelkhovsky, P TI alpha(2) corrections to parapositronium decay SO PHYSICAL REVIEW LETTERS LA English DT Article ID PRECISION-MEASUREMENT; VACUUM POLARIZATION; ORTHOPOSITRONIUM; POSITRONIUM; ORDER; WIDTH AB Two-loop QED corrections to the decay rate of parapositronium (p-Ps) into two photons are presented. We find Gamma(p-Ps --> gamma gamma) = 7989.50(2) mu s(-1). The nonlogarithmic O(alpha(2)) corrections turn out to be small, contrary to some earlier estimates. We speculate that the so-called "orthopositronium lifetime puzzle" will not likely be solved by large QED corrections. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Karlsruhe, Inst Theoret Tielchenphys, D-76128 Karlsruhe, Germany. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. RP Czarnecki, A (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 23 TC 37 Z9 37 U1 0 U2 2 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 AUG 9 PY 1999 VL 83 IS 6 BP 1135 EP 1138 DI 10.1103/PhysRevLett.83.1135 PG 4 WC Physics, Multidisciplinary SC Physics GA 223ZL UT WOS:000081871400015 ER PT J AU Liu, BG Wu, J Wang, EG Zhang, ZY AF Liu, BG Wu, J Wang, EG Zhang, ZY TI Two-dimensional pattern formation in surfactant-mediated epitaxial growth SO PHYSICAL REVIEW LETTERS LA English DT Article ID THIN-FILM GROWTH; FRACTAL GROWTH; NUCLEATION; TRANSITION; EXCHANGE; KINETICS; COMPACT; ISLANDS; AG(111); SB AB The effects of a surfactant on two-dimensional pattern formation in epitaxial growth are explored theoretically using a simple model, in which an adatom becomes immobile only after overcoming a large energy barrier as it exchanges positions with a surfactant atom, and subsequent growth from such a seed is further shielded. Within this model, a fractal-to-compact island shape transition can be induced by either decreasing the growth temperature or increasing the deposition flux. This and other intriguing findings are in excellent qualitative agreement with recent experiments. C1 Chinese Acad Sci, Inst Phys, Beijing 100080, Peoples R China. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. RP Liu, BG (reprint author), Chinese Acad Sci, Inst Phys, POB 603, Beijing 100080, Peoples R China. OI Liu, Bang-Gui/0000-0002-6030-6680 NR 27 TC 64 Z9 70 U1 6 U2 12 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 AUG 9 PY 1999 VL 83 IS 6 BP 1195 EP 1198 DI 10.1103/PhysRevLett.83.1195 PG 4 WC Physics, Multidisciplinary SC Physics GA 223ZL UT WOS:000081871400030 ER PT J AU Medarde, M Mitchell, JF Millburn, JE Short, S Jorgensen, JD AF Medarde, M Mitchell, JF Millburn, JE Short, S Jorgensen, JD TI Optimal T-C in layered manganites: Different roles of coherent and incoherent lattice distortions SO PHYSICAL REVIEW LETTERS LA English DT Article ID DOUBLE EXCHANGE; PEROVSKITE; MAGNETORESISTANCE; LA1-XCAXMNO3; TRANSITION AB Neutron powder diffraction experiments on layered manganites La2-2xSr1+2xMn2O7 (0.32 less than or equal to x less than or equal to 0.40) show that coherent lattice anomalies observed at the Curie temperature (lattice parameters, Mn-O bond lengths) reverse sign at x approximate to 0.36, coinciding with the maximum T-C approximate to 131 K. Remarkably, the anomalies are completely suppressed at this crossover composition. Incoherent distortions, as measured by anisotropic Debye-Waller factors, undergo an abrupt decrease below T-C. The magnitude of this anomaly changes very little with x and does not display any sign reversal for x approximate to 0.36. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Medarde, M (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 19 TC 60 Z9 60 U1 2 U2 8 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 AUG 9 PY 1999 VL 83 IS 6 BP 1223 EP 1226 DI 10.1103/PhysRevLett.83.1223 PG 4 WC Physics, Multidisciplinary SC Physics GA 223ZL UT WOS:000081871400037 ER PT J AU Xue, JY Duda, LC Smith, KE Fedorov, AV Johnson, PD Hulbert, SL McCarroll, W Greenblatt, M AF Xue, JY Duda, LC Smith, KE Fedorov, AV Johnson, PD Hulbert, SL McCarroll, W Greenblatt, M TI Electronic structure near the Fermi surface in the quasi-one-dimensional conductor Li0.9Mo6O17 SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHOTOEMISSION; LIQUIDS; K0.3MOO3; BRONZES AB The electronic properties of the quasi-one-dimensional (1D) oxide conductor Li0.9Mo6O17 have been investigated using high-momentum and energy resolution photoelectron spectroscopy at temperatures above and below the metal-semiconductor transition temperature. Considerable spectral intensity at the Fermi energy (E-F) is observed at room temperature, and a sharp feature corresponding to a band crossing E-F is clearly resolved for states along the quasi-1D axis. Below the metal-semiconductor transition at 24 K, a gap is clearly observed to open at E-F. Our data do not support the assertion that the low energy excitations of electrons in Li0.9Mo6O17 should be described in a Luttinger liquid model. C1 Boston Univ, Dept Phys, Boston, MA 02215 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Rutgers State Univ, Dept Chem, New Brunswick, NJ 08903 USA. RP Smith, KE (reprint author), Boston Univ, Dept Phys, Boston, MA 02215 USA. NR 23 TC 41 Z9 41 U1 0 U2 8 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 AUG 9 PY 1999 VL 83 IS 6 BP 1235 EP 1238 DI 10.1103/PhysRevLett.83.1235 PG 4 WC Physics, Multidisciplinary SC Physics GA 223ZL UT WOS:000081871400040 ER PT J AU Franceshetti, A Wang, LW Zunger, A AF Franceshetti, A Wang, LW Zunger, A TI Comment on "Quantum confinement and optical gaps in Si nanocrystals" SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRYSTALLITES C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Franceshetti, A (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 5 TC 34 Z9 34 U1 0 U2 2 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 AUG 9 PY 1999 VL 83 IS 6 BP 1269 EP 1269 DI 10.1103/PhysRevLett.83.1269 PG 1 WC Physics, Multidisciplinary SC Physics GA 223ZL UT WOS:000081871400055 ER PT J AU Ogut, S Chelikowsky, JR Louie, SG AF Ogut, S Chelikowsky, JR Louie, SG TI Comment on "Quantum confinement and optical gaps in Si nanocrystals" - Reply SO PHYSICAL REVIEW LETTERS LA English DT Article ID DOTS C1 Univ Minnesota, Minnesota Supercomp Inst, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Ogut, S (reprint author), Univ Minnesota, Minnesota Supercomp Inst, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA. RI Ogut, Serdar/B-1749-2012 NR 8 TC 7 Z9 7 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 AUG 9 PY 1999 VL 83 IS 6 BP 1270 EP 1270 DI 10.1103/PhysRevLett.83.1270 PG 1 WC Physics, Multidisciplinary SC Physics GA 223ZL UT WOS:000081871400056 ER PT J AU Chandler, DP Schuck, BL Brockman, FJ Bruckner-Lea, CJ AF Chandler, DP Schuck, BL Brockman, FJ Bruckner-Lea, CJ TI Automated nucleic acid isolation and purification from soil extracts using renewable affinity microcolumns in a sequential injection system SO TALANTA LA English DT Article; Proceedings Paper CT 9th International Conference on Flow Infection Analysis (ICFIA 98) CY AUG 23-27, 1998 CL SEATTLE, WASHINGTON DE sequential injection; flow injection analysis; renewable columns; affinity; DNA; soil; sample preparation ID HEPATITIS-A VIRUS; POLYMERASE CHAIN-REACTION; EPSTEIN-BARR-VIRUS; OLIGONUCLEOTIDE ARRAYS; HYBRIDIZATION PROPERTIES; GLASS SUPPORTS; OCEAN WATER; DNA; PCR; BACTERIA AB We have combined affinity purification concepts with novel renewable-surface microcolumns in a sequential injection system for the automated and rapid isolation and purification of nucleic acids directly from crude soil extracts. Geobacter chapellii DNA was spiked at femtomolar concentrations into clean solutions or crude soil extracts containing picomolar concentrations of competitive DNA, humic acids and other soluble soil constituents. The 16S rDNA targets (indigenous and spiked) were purified and eluted in less than 20 min in a form suitable for direct polymerase chain reaction (PCR) amplification and detection. The extraction efficiency of the automated system was equivalent to a 4-h batch reaction using identical reagents. The estimated efficiency of isolation and purification was maximally 30% under the conditions employed here, with levels comparable to those obtained with soils/sediments processed by standard techniques, and a detection limit of 1.7 attamoles (10(6) copies) Geobacter target in a soil extract containing a competitive background of 10(9) genomes. This manuscript represents the first report of automated nucleic acid purification from an environmental sample using sequential injection fluidic systems and renewable microcolumn technology, and provides an excellent platform from which to optimize and accelerate the development of an integrated microbial/nucleic acid detector. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Battelle Pacific NW Natl Lab, Environm Microbiol Grp, Richland, WA 99352 USA. Battelle Pacific NW Natl Lab, Chem Sensors & Microanlayt Syst, Richland, WA 99352 USA. RP Chandler, DP (reprint author), Battelle Pacific NW Natl Lab, Environm Microbiol Grp, 902 Battelle Blvd,POB 999,Mail Stop P7-50, Richland, WA 99352 USA. NR 46 TC 29 Z9 29 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-9140 J9 TALANTA JI Talanta PD AUG 9 PY 1999 VL 49 IS 5 BP 969 EP 983 DI 10.1016/S0039-9140(99)00074-0 PG 15 WC Chemistry, Analytical SC Chemistry GA 230QZ UT WOS:000082263000002 PM 18967673 ER PT J AU Li, X Liu, SS Chen, WW Wang, LS AF Li, X Liu, SS Chen, WW Wang, LS TI The electronic structure of MoC and WC by anion photoelectron spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY CURVES; BINDING-ENERGIES; NEGATIVE-IONS; MONOCARBIDE; CLUSTERS; SPECTRA; STATES; PTC AB Photoelectron spectra of MoC- and WC- are reported at two detachment energies, 532 and 355 nm. The electron affinities of MoC and WC were measured to be 1.358 (0.010) and 1.022 (0.010) eV, respectively. Seven low-lying electronic states were observed for MoC within 2 eV above its ground state whereas six were observed for WC within 2.4 eV above its ground state. The bonding and spectroscopy of MoC and WC were found to be different and were attributed to their different atomic configurations due to the strong relativistic effects in W. The current study reports the first spectroscopic information on WC. (C) 1999 American Institute of Physics. [S0021-9606(99)01330-6]. C1 Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Wang, LS (reprint author), Washington State Univ, Dept Phys, 2710 Univ Dr, Richland, WA 99352 USA. NR 18 TC 25 Z9 25 U1 4 U2 21 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 8 PY 1999 VL 111 IS 6 BP 2464 EP 2469 DI 10.1063/1.479523 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 221EN UT WOS:000081711200013 ER PT J AU Ashurst, WT Holian, BL AF Ashurst, WT Holian, BL TI Droplet size dependence upon volume expansion rate SO JOURNAL OF CHEMICAL PHYSICS LA English DT Letter C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Ashurst, WT (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. NR 2 TC 7 Z9 7 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 8 PY 1999 VL 111 IS 6 BP 2842 EP 2843 DI 10.1063/1.479561 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 221EN UT WOS:000081711200053 ER PT J AU Semak, VV Damkroger, B Kempka, S AF Semak, VV Damkroger, B Kempka, S TI Temporal evolution of the temperature field in the beam interaction zone during laser material processing SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID VAPORIZATION; DYNAMICS AB This paper presents a numerical simulation of the temperature field resulting from the impingement of a laser beam on a metal surface. The calculations were based on a hydrodynamic physical model of laser-material interaction, which includes the effect of evaporation recoil pressure on melt flow and the related convective heat transfer. The computations follow an experimentally verified physical-model of melt hydrodynamics and the model of laser-induced evaporation developed by Anisimov. The simulations indicate that convective heat transfer which is induced by recoil pressure is significant for absorbed laser intensities from 0.5 MW cm(-2) to 10 MW cm(-2). This range corresponds to laser welding, cutting and drilling due to melt ejection (hydrodynamic drilling). The simulations also show that the motion of the melt from the centre of the beam interaction zone towards the periphery results in a secondary maxima in the temperature distribution, which in turn can lead to instability of the melt Row and temperature field fluctuations. The model also predicts that the cooling rate in and around the fusion zone is strongly influenced by the recoil-pressure-induced melt Row. At the centre of the beam interaction zone, the cooling rate is much higher (similar to 10 times), and at the periphery, much slower than predicted by a pure heat conduction model. C1 New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Semak, VV (reprint author), Penn State Univ, Appl Res Lab, State Coll, PA 16804 USA. NR 22 TC 47 Z9 49 U1 1 U2 13 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD AUG 7 PY 1999 VL 32 IS 15 BP 1819 EP 1825 DI 10.1088/0022-3727/32/15/309 PG 7 WC Physics, Applied SC Physics GA 228AZ UT WOS:000082114500014 ER PT J AU Semak, VV Bragg, WD Damkroger, B Kempka, S AF Semak, VV Bragg, WD Damkroger, B Kempka, S TI Transient model for the keyhole during laser welding SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID DYNAMICS AB A novel approach to simulating the dominant dynamic processes present during concentrated energy beam welding of metals is presented. A model for the transient behaviour of the front keyhole wall is developed. It is assumed that keyhole propagation is dominated by evaporation-recoil-driven melt expulsion from the beam interaction zone. Results from the model show keyhole instabilities consistent with experimental observations of metal welding, metal cutting and ice welding. C1 Penn State Univ, Appl Res Lab, State Coll, PA 16804 USA. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Semak, VV (reprint author), Penn State Univ, Appl Res Lab, State Coll, PA 16804 USA. NR 13 TC 48 Z9 49 U1 0 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD AUG 7 PY 1999 VL 32 IS 15 BP L61 EP L64 DI 10.1088/0022-3727/32/15/103 PG 4 WC Physics, Applied SC Physics GA 228AZ UT WOS:000082114500003 ER PT J AU Dimitrijevic, NM Bartels, DM Jonah, CD Takahashi, K AF Dimitrijevic, NM Bartels, DM Jonah, CD Takahashi, K TI Pulse radiolytic studies of supercritical CO2 SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DIFFUSION-CONTROLLED REACTIONS; ELECTRON-TRANSFER REACTION; FLUIDS; CHEMISTRY; MIXTURES; RANGE AB The species produced by ionizing radiation in supercritical CO2 have been measured at a reduced temperature of 1.03 from 78 to 117 bar, It has been shown that C2O4+ is formed. This then reacts with positive ion scavengers. Its rate constant with dimethylaniline is 1.2 x 10(11) l mol(-1) s(-1) at 104 bar. The amount of C2O4+ formed is not proportional to the CO2 density. This is attributed to an increased escape of the geminate ions at lower densities, We have also measured the production of ozone, which implies the production of O atoms and a production of oxygen molecules, Published by Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Hokkaido Univ, Div Quantum Energy Engn, Sapporo, Hokkaido 060, Japan. RP Jonah, CD (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Takahashi, Kenji/C-8846-2011; Takahashi, Kenji/F-4885-2014 NR 25 TC 16 Z9 16 U1 0 U2 4 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 AUG 6 PY 1999 VL 309 IS 1-2 BP 61 EP 68 DI 10.1016/S0009-2614(99)00674-0 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 224XX UT WOS:000081926200009 ER PT J AU Greensite, J Olesen, P AF Greensite, J Olesen, P TI Worldsheet fluctuations and the heavy quark potential in the AdS/CFT approach SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE strong coupling expansion; confinement ID N GAUGE-THEORY; THERMAL FLUCTUATIONS; STRING THEORY; DEPENDENCE; MEMBRANES AB We consider contributions to the heavy quark potential, in the AdS/CFT approach to SU(N) gauge theory, which arise from first order fluctuations of the associated worldsheet in anti-deSitter space. The gaussian fluctuations occur around a classical worldsheet configuration resembling an infinite square well, with the bottom of the well lying at the AdS horizon. The eigenvalues of the corresponding laplacean operators can be shown numerically to be very close to those in at space. We find that two of the transverse world sheet fields become massive, which may have implications for the existence of a Luscher term in the heavy quark potential. It is also suggested that these massive degrees of freedom may relate to extrinsic curvature in an effective D = 4 string theory. C1 San Francisco State Univ, Dept Phys & Astron, San Francisco, CA 94117 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. Niels Bohr Inst, DK-2100 Copenhagen O, Denmark. RP Greensite, J (reprint author), San Francisco State Univ, Dept Phys & Astron, San Francisco, CA 94117 USA. EM greensit@stars.sfsu.edu; polesen@nbi.dk NR 24 TC 49 Z9 49 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD AUG 6 PY 1999 IS 4 AR 001 PG 18 WC Physics, Particles & Fields SC Physics GA 224MH UT WOS:000081902500001 ER PT J AU Van Siclen, CD AF Van Siclen, CD TI Anomalous walker diffusion through composite systems SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID PERCOLATION; CONDUCTIVITY; CLUSTERS AB Diffusion of a non-biased walker through a composite (multi-phase) system is shown to be anomalous for length scales less than the correlation length xi (i.e., when the path length is measured with a ruler of length less than xi) and Gaussian for length scales greater than xi. The values of xi and the fractal dimension d(w) of the walker path in the anomalous regime reflect the phase properties and phase domain morphology of the composite. They are related to the diffusion coefficient D-w for walker diffusion in the Gaussian regime by D-w proportional to xi(2-dw), and to the macroscopic transport coefficient sigma through the relation sigma proportional to D-w. The correlation length xi thus gives the size above which the composite is effectively homogeneous with respect to the transport property of interest. Walker behaviour is compared for disordered (random), particulate-matrix, and labyrinthine two-phase microstructures. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Van Siclen, CD (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 17 TC 3 Z9 3 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD AUG 6 PY 1999 VL 32 IS 31 BP 5763 EP 5771 PG 9 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 225UK UT WOS:000081983000005 ER PT J AU Molina, PE Ahmed, N Ajmal, M Dewey, S Volkow, N Fowler, J Abumrad, N AF Molina, PE Ahmed, N Ajmal, M Dewey, S Volkow, N Fowler, J Abumrad, N TI Co-administration of gamma-vinyl GABA and cocaine: Preclinical assessment of safety SO LIFE SCIENCES LA English DT Article DE cocaine; ALT; toxicity; GVG; cardiac rhythm; MABP; addiction ID VIGABATRIN; ALANINE; ENDURANCE; DOPAMINE; RELEASE; ABUSE; RATS AB Gamma-vinyl GABA (GVG, Vigabatrin), an irreversible inhibitor of GABA transaminase (GABA-T) that inhibits cocaine-induced place preference and self administration has been proposed as a treatment for cocaine addiction. It was therefore important to assess if there was an enhanced toxicity from the combination of GVG with cocaine. No mortality was observed with administration of GVG (60 mg/kg IV) alone (n=8) or in combination (n=6) with cocaine (5 mg/kg IV). Cocaine-induced EKG alterations were not affected by GVG pretreatment. Plasma alanine amino transferase activity was reduced by GVG treatment and this was not further modified by cocaine administration. These results suggest that acute co-administration of GVG and cocaine does not result in immediate cardiovascular or hepatic toxicity of sufficient significance, to preclude further clinical trials. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. N Shore Univ Hosp, Dept Surg, Manhasset, NY 11030 USA. RP Molina, PE (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. FU NIGMS NIH HHS [7RO1 GM50567-05] NR 18 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 0024-3205 J9 LIFE SCI JI Life Sci. PD AUG 6 PY 1999 VL 65 IS 11 BP 1175 EP 1182 DI 10.1016/S0024-3205(99)00351-3 PG 8 WC Medicine, Research & Experimental; Pharmacology & Pharmacy SC Research & Experimental Medicine; Pharmacology & Pharmacy GA 228QU UT WOS:000082147800009 PM 10503933 ER PT J AU Back, CH Allenspach, R Weber, W Parkin, SSP Weller, D Garwin, EL Siegmann, HC AF Back, CH Allenspach, R Weber, W Parkin, SSP Weller, D Garwin, EL Siegmann, HC TI Minimum field strength in precessional magnetization reversal SO SCIENCE LA English DT Article ID THIN-FILMS; PHOTOEMISSION; MAGNETISM; PARTICLES; DYNAMICS; PULSES AB Ultrafast magnetic field pulses as short as 2 picoseconds are able to reverse the magnetization in thin, in-plane, magnetized cobalt films. The field pulses are applied in the plane of the film, and their direction encompasses all angles with the magnetization. At a right angle to the magnetization, maximum torque is exerted on the spins. In this geometry, a precessional magnetization reversal can be triggered by fields as small as 184 kiloamperes per meter. Applications in future ultrafast magnetic recording schemes can be foreseen. C1 ETH Zurich, Festkorperphys Lab, CH-8093 Zurich, Switzerland. IBM Corp, Div Res, Zurich Res Lab, CH-8803 Ruschlikon, Switzerland. IBM Corp, Almaden Res Ctr, Div Res, San Jose, CA 95120 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94305 USA. RP Back, CH (reprint author), ETH Zurich, Festkorperphys Lab, CH-8093 Zurich, Switzerland. RI Back, Christian/A-8969-2012; Parkin, Stuart/D-2521-2012 OI Back, Christian/0000-0003-3840-0993; NR 17 TC 214 Z9 219 U1 3 U2 38 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 6 PY 1999 VL 285 IS 5429 BP 864 EP 867 DI 10.1126/science.285.5429.864 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 223UX UT WOS:000081860900041 ER PT J AU Gutierrez-Mora, F Dominguez-Rodriguez, A Routbort, JL Chaim, R Guiberteau, F AF Gutierrez-Mora, F Dominguez-Rodriguez, A Routbort, JL Chaim, R Guiberteau, F TI Joining of yttria-tetragonal stabilized zirconia polycrystals using nanocrystals SO SCRIPTA MATERIALIA LA English DT Article DE bonding; ceramics; plasticity ID SUPERPLASTIC FLOW C1 Technion Israel Inst Technol, Dept Mat Engn, IL-32000 Haifa, Israel. Univ Extremadura, Dept Fis, Badajoz 61070, Spain. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Gutierrez-Mora, F (reprint author), Technion Israel Inst Technol, Dept Mat Engn, IL-32000 Haifa, Israel. RI Gutierrez-Mora, Felipe/H-4625-2015; OI Gutierrez-Mora, Felipe/0000-0003-3632-7163; Dominguez-Rodriguez, Arturo/0000-0003-1598-5669 NR 11 TC 22 Z9 22 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD AUG 6 PY 1999 VL 41 IS 5 BP 455 EP 460 DI 10.1016/S1359-6462(99)00190-6 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 227EN UT WOS:000082065500001 ER PT J AU Engler, O Kong, XW Lucke, K AF Engler, O Kong, XW Lucke, K TI Development of microstructure and texture during rolling of single-phase and two-phase cube-oriented Al-Cu single crystals SO SCRIPTA MATERIALIA LA English DT Article ID CHANNEL DIE COMPRESSION; ALUMINUM; RECRYSTALLIZATION; NUCLEATION; PARTICLES; ORIENTATION; DEFORMATION; ALLOYS C1 Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. Rhein Westfal TH Aachen, Inst Met Kunde & Met Phys, D-52056 Aachen, Germany. RP Engler, O (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Mail Stop K765, Los Alamos, NM 87545 USA. NR 25 TC 23 Z9 23 U1 0 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD AUG 6 PY 1999 VL 41 IS 5 BP 493 EP 503 DI 10.1016/S1359-6462(99)00180-3 PG 11 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 227EN UT WOS:000082065500007 ER PT J AU Wang, P Woodward, CA Kaufman, EN AF Wang, P Woodward, CA Kaufman, EN TI Poly(ethylene glycol)-modified ligninase enhances pentachlorophenol biodegradation in water-solvent mixtures SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE pentachlorophenol; ligninase; poly(ethylene glycol); organic solvent; nonaqueous enzymatic biocatalysis ID FUNGUS PHANEROCHAETE-CHRYSOSPORIUM; POLYCYCLIC AROMATIC-HYDROCARBONS; MISCIBLE ORGANIC-SOLVENTS; POLYCHLORINATED PHENOLS; OXIDATIVE-DEGRADATION; ENZYMATIC CATALYSIS; DEGRADING ENZYME; PEROXIDASE; SOIL; HYDROPHOBICITY AB Polychlorinated hydrocarbons are prevalent environmental contaminants whose rates of biodegradation are limited by their minimal solubilities in aqueous solutions where the biological reactions take place. In this study, ligninase (LiP) from Phanerochaete chrysosporium was modified by poly(ethylene glycol) to enhance its activity and stability for the biodegradation of pentachlorophenol (PCP) in the presence of acetonitrile (MeCN), a water-miscible solvent. The modified enzyme retained 100% of its activity in aqueous solutions and showed enhanced tolerance against the organic solvent. The activity of the modified enzyme was found to be over twice that of the native enzyme in the presence of 10% (v/v) MeCN. The solubility of PCP was enhanced significantly by the addition of MeCN to aqueous solutions, such that it was over 10-fold more soluble in the presence of 15% (v/v) MeCN than in pure aqueous buffer solution (from 0.06 to 0.65 mM). Capitalizing on the enhanced substrate solubility and the increased activity of the modified enzyme, the catalytic efficiency of the modified LiP in solutions containing 15% MeCN was over 11-fold higher than that of the native enzyme in buffer solutions (pH 4.2) in unoptimized reactor systems (from 44 to 480 mol PCP/mol LiP.h). Continued research both in the use of organic solvents to increase the availability of recalcitrant contaminants and in the modification of enzymes to enhance their activity and stability in such solvents promises to dramatically affect our ability to remediate contaminated sites. Published by John Wiley & Sons. C1 Oak Ridge Natl Lab, Div Chem Technol, Bioproc Res & Dev Ctr, Oak Ridge, TN 37831 USA. RP Kaufman, EN (reprint author), Oak Ridge Natl Lab, Div Chem Technol, Bioproc Res & Dev Ctr, Oak Ridge, TN 37831 USA. NR 39 TC 29 Z9 32 U1 0 U2 3 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD AUG 5 PY 1999 VL 64 IS 3 BP 290 EP 297 DI 10.1002/(SICI)1097-0290(19990805)64:3<290::AID-BIT5>3.0.CO;2-K PG 8 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 208WL UT WOS:000081014800005 ER PT J AU Sherwood, JL Petersen, JN Skeen, RS AF Sherwood, JL Petersen, JN Skeen, RS TI Biotransformation of carbon tetrachloride by various acetate- and nitrate-limited denitrifying consortia SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE carbon tetrachloride; consortia; denitrification ID SP STRAIN-KC; HALOGENATED ORGANIC-COMPOUNDS; DENITRIFICATION CONDITIONS; ELECTRON-DONOR; TRANSFORMATION; BIODEGRADATION; 1,1,1-TRICHLOROETHANE; DECHLORINATION AB Fed-batch experiments were performed to determine the carbon tetrachloride (CT)-degrading ability of three denitrifying consortia cultured from sites not contaminated with CT. A mathematical model was used to quantify the rates of CT transformation by the consortia under both acetate-limiting and nitrate-limiting conditions. A rate constant for CT transformation on a cellular protein basis and the fraction of degraded CT transformed to chloroform (CF) were determined for each consortium by optimizing the model to fit the experimental data. The parameters for these experiments were statistically compared to those obtained for previous experiments with a denitrifying consortium cultured from an aquifer soil sample from the US Department of Energy Hanford site in southeastern Washington state. Results of F-test analysis indicated the rate of CT transformation and the production of CF both were functions of the limiting nutrient. Under nitrate-limited conditions, the rate constant for CT transformation for all four consortia was about 30 L/gmol/min and approximately 50% of the CT transformed was converted to CF. When acetate was the limiting nutrient, the rate constant for CT transformation was approximately 8 L/gmol/min and the CF yield decreased to about 25%. These results imply the ability to degrade CT may be inherent to some denitrifying organisms, regardless of previous exposure to CT. (C) 1999 John Wiley & Sons, Inc. C1 Washington State Univ, Ctr Multiphase Environm Res, Pullman, WA 99164 USA. Pacific NW Natl Lab, Bioproc Grp, Richland, WA 99352 USA. RP Petersen, JN (reprint author), Washington State Univ, Ctr Multiphase Environm Res, POB 642710, Pullman, WA 99164 USA. RI Petersen, James/B-8924-2008 NR 31 TC 2 Z9 2 U1 1 U2 3 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD AUG 5 PY 1999 VL 64 IS 3 BP 342 EP 348 DI 10.1002/(SICI)1097-0290(19990805)64:3<342::AID-BIT10>3.0.CO;2-4 PG 7 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 208WL UT WOS:000081014800010 ER PT J AU Ressler, T Brock, SL Wong, J Suib, SL AF Ressler, T Brock, SL Wong, J Suib, SL TI Multiple-scattering EXAFS analysis of tetraalkylammonium manganese oxide colloids SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID X-RAY-ABSORPTION; BUCKLED CRYSTALLINE-STRUCTURE; DISORDERED MIXED SALTS; NA-RICH BIRNESSITE; FINE-STRUCTURE; HEXAGONAL BIRNESSITE; HYDROUS OXIDES; SPECTROSCOPY; MN; FE AB X-ray absorption spectroscopy at the Mn K edge was employed to elucidate the structure of colloidal tetraalkylammonium (TAA) manganese oxides in sols and gels obtained by different preparation and heat treatment procedures. Two series of colloidal TAA MnO(x) prepared with tetrapropylammonium (TPA) and tetraethylammonium (TEA) cations were studied. Several manganese oxides, birnessite, and feitknechtite were also measured and served as model compounds for structural refinements. Near edge structure (XANES) analysis revealed different average valences of the colloidal systems. As synthesized and heat-treated, TAA colloids exhibited an average valence of 3.6-3.7, whereas gelled TAA colloids showed a lower average valence of similar to 3.5. Extended absorption fine structure (EXAFS) analysis was carried out to distances of -6.0 Angstrom around the central Mn atom using theoretical backscattering phases and amplitudes calculated from the ab initio FEFF code. All multiple-scattering (MS) paths with a weight of 2% and more with respect to the main Fourier transform peak were included in the refinement. It is found that, except for gelled TAA samples, no significant amount of corner-shared MnO(6) units was detected in the colloidal systems. Theoretical EXAFS phases and amplitudes were derived for a monoclinic birnessite MnO(x) layer structure consisting of edge-shared MnO(6) octahedra. EXAFS refinements utilizing these phases and amplitudes resulted in good agreement with experimental data. Differences in the refined scattering shell distances between the TPA and TEA series suggest a structure influencing effect of the two ammonium ions. Bond angles between neighboring MnO(6) octahedra were determined from the amplitude dependence of a collinear Mn-Mn-Mn MS path on deviations from 180 degrees ("focusing effect"). On the basis of the bond angles, and with use of the average valence to define the distribution of tri- and tetravalent manganese in the MnO(x) layers, three distinct 2D structures are proposed: one for birnessite, one for TAA sols, and one for TAA gels. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Connecticut, Dept Chem, Storrs, CT 06269 USA. Univ Connecticut, Dept Chem Engn, Storrs, CT 06269 USA. Univ Connecticut, Inst Sci Mat, Storrs, CT 06269 USA. RP Ressler, T (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. EM ressler@fhi-berlin.mpg.de OI Brock, Stephanie/0000-0002-0439-302X NR 41 TC 99 Z9 99 U1 0 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD AUG 5 PY 1999 VL 103 IS 31 BP 6407 EP 6420 DI 10.1021/jp9835972 PG 14 WC Chemistry, Physical SC Chemistry GA 227UW UT WOS:000082099200004 ER PT J AU Lee, YC Curtiss, LA Ratner, MA Shriver, DF AF Lee, YC Curtiss, LA Ratner, MA Shriver, DF TI Computational studies of polyelectrolytes containing zeolitic fragments SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ELECTRICAL RESPONSE; PROTON AFFINITIES; ABINITIO; ELECTROLYTES; FRAMEWORK; SIZE; BOND AB The structures and sodium affinities of a series of zeolitic fragments [H3Al(OCH3)(x)(OSiH3)(1-x)(-), 2T, H2Al(OCH3)(x)(OSiH3)(2-x)(-), 3T, Al(OCH3)(x)(OSiH3)(4-x)(-), 5T] that mimic the charge sites in polyelectrolytes are calculated by ab initio molecular orbital methods at different levels of theory. At the HF/6-31G* level, the decrease in the sodium affinity due to the substitution of an OCH3 group by an OSiH3 group is about 8 kcal/mol in the 2T and 3T systems. In the 5T systems, the replacement of a sodium-coordinated OCH3 group by an OSiH3 group causes a decrease of 7 kcal/mol in the sodium affinity, while the substitution for a non-sodium-coordinated OCH3 group results in a 2.7 kcal/mol decrease. The lower sodium affinity indicates a weaker Coulombic interaction, suggesting an enhanced ionic conductivity with the substitution of carbon by silicon, consistent with experimental results. Natural bond orbital (NBO) analyses show that silicon-bonded oxygen atoms have smaller lone-pair dipole moments, resulting in a lower sodium affinity. The substitution of aluminum by boron leads to a higher sodium affinity, although the effect of replacing an OCH3 group by an OSiH3 group still reduces the sodium affinity. The effect of the sodium cation on the bond angles in these systems is also investigated. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Northwestern Univ, Ctr Mat Res, Evanston, IL 60208 USA. RP Curtiss, LA (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 38 TC 3 Z9 3 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD AUG 5 PY 1999 VL 103 IS 31 BP 6445 EP 6449 DI 10.1021/jp990649u PG 5 WC Chemistry, Physical SC Chemistry GA 227UW UT WOS:000082099200009 ER PT J AU Brisudova, M Burakovsky, L Goldman, T AF Brisudova, M Burakovsky, L Goldman, T TI Effect of color screening on heavy quarkonia Regge trajectories SO PHYSICS LETTERS B LA English DT Article DE Regge trajectories; spectroscopy; potential models; color screening ID SCALAR MATTER; GAUGE-THEORY; QCD; CONFINEMENT; SCATTERING; FERMIONS; PHYSICS AB Using an unquenched lattice potential to calculate the spectrum of a bottomonium-like system, we demonstrate numerically that the effect of pair creation is to produce termination of the real part of hadronic Regge trajectories, in contrast to the Veneziano model and the vast majority of phenomenological generalizations. Termination of the real part of Regge trajectories may have significant experimental consequences. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Brisudova, M (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, MS B283, Los Alamos, NM 87545 USA. NR 30 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 5 PY 1999 VL 460 IS 1-2 BP 1 EP 7 DI 10.1016/S0370-2693(99)00732-7 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 225NV UT WOS:000081968400001 ER PT J AU Kauer, N Reina, L Repond, J Zeppenfeld, D AF Kauer, N Reina, L Repond, J Zeppenfeld, D TI NLO QCD predictions for internal jet shapes in DIS at HERA SO PHYSICS LETTERS B LA English DT Article ID HIGHER-ORDER CORRECTIONS; TO-LEADING ORDER; HADRON COLLIDERS; P(P)OVER-BAR COLLISIONS; CROSS-SECTIONS; TEV; EP AB The transverse momentum flow inside jets is a sensitive measure of internal jet structure. For the current jets in deep inelastic scattering this jet shape measure is determined at order alpha(s)(2), i.e. with up to three partons inside a single jet. The scale dependence of jet shapes in various jet algorithms is discussed. Results agree well with recent measurements by the ZEUS Collaboration, without introducing the hadronization parameter R-sep. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Kauer, N (reprint author), Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA. NR 26 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD AUG 5 PY 1999 VL 460 IS 1-2 BP 189 EP 196 DI 10.1016/S0370-2693(99)00735-2 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 225NV UT WOS:000081968400028 ER PT J AU Huynh, WU Peng, XG Alivisatos, AP AF Huynh, WU Peng, XG Alivisatos, AP TI CdSe nanocrystal rods/poly(3-hexylthiophene) composite photovoltaic devices SO ADVANCED MATERIALS LA English DT Article ID LIGHT-EMITTING-DIODES; DONOR-ACCEPTOR HETEROJUNCTIONS; SIDE-CHAIN LENGTH; CHARGE SEPARATION; POLYMERS; PHOTODIODES; FILMS; CELLS AB Communication: Photovoltaic devices remain an important aim for thin films of conjugated polymers. Here is reported the construction of devices with improved photovoltaic performance, which is achieved by blending elongated CdSe nanocrystals (see Figure) with regioregular poly(3-hexylthiophene). Improved transport arising from denser aggregation between the elongated particles is a probable source of the enhanced energy conversion. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Alivisatos, AP (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Alivisatos , Paul /N-8863-2015; peng, xiaogang/R-6184-2016 OI Alivisatos , Paul /0000-0001-6895-9048; peng, xiaogang/0000-0002-5606-8472 NR 19 TC 504 Z9 519 U1 5 U2 114 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD AUG 3 PY 1999 VL 11 IS 11 BP 923 EP + DI 10.1002/(SICI)1521-4095(199908)11:11<923::AID-ADMA923>3.0.CO;2-T PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 228YK UT WOS:000082165000012 ER PT J AU Salaniwal, S Cui, ST Cummings, PT Cochran, HD AF Salaniwal, S Cui, ST Cummings, PT Cochran, HD TI Self-assembly of reverse micelles in water/surfactant/carbon dioxide systems by molecular simulation SO LANGMUIR LA English DT Letter ID SUPERCRITICAL CARBON-DIOXIDE; DYNAMICS SIMULATIONS; COMPUTER-SIMULATIONS; WATER; MICROEMULSIONS; FLUIDS; SURFACTANTS; EXTRACTION; CO2 AB One of the primary reasons that supercritical carbon dioxide has thus far failed to achieve its full potential as an environmentally benign alternative to conventional industrial solvents is that few surfactants are known at present for use in CO2. As an initial step toward developing the molecular-level understanding needed to design new surfactants, we report the first molecular simulations of the self-assembly of dichain surfactants in supercritical carbon dioxide into stable, spherical aggregates. These aggregates exhibit the expected characteristics of reverse micelles with aqueous cores, consistent, with earlier experimental findings, demonstrating the potential of molecular simulation for modeling such complex systems. C1 Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Cummings, PT (reprint author), Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 29 TC 79 Z9 80 U1 1 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD AUG 3 PY 1999 VL 15 IS 16 BP 5188 EP 5192 DI 10.1021/la9904556 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 227KJ UT WOS:000082079300002 ER PT J AU Parikh, AN Beers, JD Shreve, AP Swanson, BI AF Parikh, AN Beers, JD Shreve, AP Swanson, BI TI Infrared spectroscopic characterization of lipid-alkylsiloxane hybrid bilayer membranes at oxide substrates SO LANGMUIR LA English DT Review ID SELF-ASSEMBLED MONOLAYERS; SURFACE-PLASMON RESONANCE; SINGLE PHOSPHOLIPID-BILAYERS; LANGMUIR-BLODGETT-FILMS; X-RAY REFLECTIVITY; MOLECULAR-STRUCTURE; VIBRATIONAL-SPECTRA; N-OCTADECYLTRICHLOROSILANE; AIR/WATER INTERFACE; PHYSICAL-PROPERTIES AB Successive depositions of precompressed Langmuir monolayers have been shown to allow reproducible formation of air-stable, lipid-alkylsiloxane hybrid bimolecular architectures at oxidic supports. Specifically, prepolymerized Langmuir-Blodgett films of n-octadecylsiloxane (OTS) monolayers on oxided silicon substrates were used as the hydrophobic templates, upon which compressed monolayers of dipalmitoyl-sn1-glycerophosphatidylcholine (DPPC) and monosialogangliosides (Gm1) were deposited from a low-temperature air-water interface by the horizontal deposition method. Structural features of each leaflet of the resultant bimolecular architectures, namely DPPC/OTS/SiO2/Si and Gm1/OTS/SiO2/Si, were characterized using a combined application of infrared spectroscopy, null-ellipsometry, and surface wetting measurements. In both cases, the outer lipid leaflet (DPPC or Gm1) was found to be structurally decoupled with respect to the inner OTS layer. The inner silane layer was composed of essentially untilted (cant angle, theta = 0 - 10 degrees), all-trans chains at the dense packing of similar to 19 Angstrom(2)/molecule, consistent with the previously reported structure in solution-phase assembled OTS monolayers. The outer DPPC leaflet, however, was found to be composed of collectively tilted (theta = 36 degrees), all-trans acyl chains at the lower chain-packing density (similar to 26-28 Angstrom(2)/chain) whereas the outer Gm1 leaflet was concluded to have essentially untilted chains at similarly lower chain-packing densities (similar to 23-26 Angstrom(2)/chain) but with the carbohydrate head-groups disposed in a topologically staggered conformation. The structural independence of the two leaflets in the two classes of bilayered architectures examined here confirms the possibility of independently manipulating the molecular structure in each leaflet of supported hybrid bilayers. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Adv Instrumentat & Diagnost Grp, Los Alamos, NM 87545 USA. RP Parikh, AN (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Adv Instrumentat & Diagnost Grp, CST 1, Los Alamos, NM 87545 USA. RI PARIKH, ATUL/D-2243-2014 OI PARIKH, ATUL/0000-0002-5927-4968 NR 111 TC 38 Z9 38 U1 5 U2 25 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD AUG 3 PY 1999 VL 15 IS 16 BP 5369 EP 5381 DI 10.1021/la9813679 PG 13 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 227KJ UT WOS:000082079300030 ER PT J AU Emery, VJ Kivelson, SA Tranquada, JM AF Emery, VJ Kivelson, SA Tranquada, JM TI Stripe phases in high-temperature superconductors SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID T-J MODEL; MAGNETIC FLUCTUATIONS; SEPARATION; LIQUID; HOLES; ANTIFERROMAGNETS; LA2-XSRXCUO4; DIFFRACTION; MECHANISM; METALS AB Stripe phases are predicted and observed to occur in a class of strongly correlated materials describable as doped antiferromagnets, of which the copper-oxide superconductors are the most prominent representatives. The existence of stripe correlations necessitates the development of new principles for describing charge transport and especially superconductivity in these materials. C1 Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Kivelson, SA (reprint author), Univ Calif Los Angeles, Dept Phys, 405 Hilgard Ave, Los Angeles, CA 90095 USA. RI Tranquada, John/A-9832-2009 OI Tranquada, John/0000-0003-4984-8857 NR 43 TC 268 Z9 270 U1 3 U2 21 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 AUG 3 PY 1999 VL 96 IS 16 BP 8814 EP 8817 DI 10.1073/pnas.96.16.8814 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 223HL UT WOS:000081835500006 PM 10430848 ER PT J AU Pande, VS Rokhsar, DS AF Pande, VS Rokhsar, DS TI Molecular dynamics simulations of unfolding and refolding of a beta-hairpin fragment of protein G SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID TRANSITION-STATE; ENERGY; WATER; STABILITY; PATHWAYS; BARNASE; MODEL; VIEW AB We have studied the unfolding and refolding pathway of a beta-hairpin fragment of protein G by using molecular dynamics. Although this fragment is small, it possesses several of the qualities ascribed to small proteins: cooperatively formed beta-sheet secondary structure and a hydrophobic "core'' of packed side chains. At high temperatures, we find that the beta-hairpin unfolds through a series of sudden, discrete conformational changes. These changes occur between states that are identified with the folded state, a pair of partially unfolded kinetic intermediates, and the unfolded state. To study refolding at low temperatures, we perform a series of short simulations starting from the transition states of the discrete transitions determined by the unfolding simulations. C1 Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Rokhsar, DS (reprint author), Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. NR 34 TC 284 Z9 287 U1 3 U2 17 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 AUG 3 PY 1999 VL 96 IS 16 BP 9062 EP 9067 DI 10.1073/pnas.96.16.9062 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 223HL UT WOS:000081835500053 PM 10430895 ER PT J AU Gabriel, JM Merchant, M Ohta, T Ji, Y Caldwell, RG Ramsey, MJ Tucker, JD Longnecker, R Nicholls, RD AF Gabriel, JM Merchant, M Ohta, T Ji, Y Caldwell, RG Ramsey, MJ Tucker, JD Longnecker, R Nicholls, RD TI A transgene insertion creating a heritable chromosome deletion mouse model of Prader-Willi and Angelman syndromes SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE imprinting; epigenetic; failure-to-thrive methylation; non-Merdeliar ID ALLELE-SPECIFIC REPLICATION; BETA-3 SUBUNIT; IMPRINTED GENE; CLEFT-PALATE; NECDIN GENE; MICE; MUTATIONS; ABSENCE; REGION AB Prader-Willi syndrome (PWS) and Angelman syndrome (AS) result from the loss of function of imprinted genes in human chromosome 15q11-q13, The central part of mouse chromosome 7 is homologous to human 15q11-q13, with conservation of both gene order and imprinted features. We report here the characterization of a transgene insertion (Epstein-Barr virus Latent Membrane Protein 2A, LMP2A) into mouse chromosome 7C, which has resulted in mouse models for PWS and AS dependent on the sex of the transmitting parent. Epigenotype (allelic expression and DNA methylation) and fluorescence in situ hybridization analyses indicate that the transgene-induced mutation has generated a complete deletion of the PWS/AS-homologous region but has not deleted flanking loci. Because the intact chromosome 7, opposite the deleted homolog, maintains the correct imprint in somatic cells of PWS and AS mice and establishes the correct imprint in male and female germ cells of AS mice, homologous association and replication asynchrony are not part of the imprinting mechanism. This heritable-deletion mouse model will be particularly useful for the identification of the etiological genes and mechanisms, phenotypic basis, and investigation of therapeutic approaches for PWS. C1 Case Western Reserve Univ, Sch Med, Dept Genet, Cleveland, OH 44106 USA. Univ Hosp Cleveland, Ctr Human Genet, Cleveland, OH 44106 USA. Northwestern Univ, Dept Microbiol Immunol, Chicago, IL 60611 USA. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Nicholls, RD (reprint author), Case Western Reserve Univ, Sch Med, Dept Genet, 10900 Euclid Ave, Cleveland, OH 44106 USA. OI Merchant, Mark/0000-0003-0690-8581 FU NCI NIH HHS [T32 CA009560, R01 CA073507, R01 CA062234]; NIAID NIH HHS [T32 AI007476]; NICHD NIH HHS [HD31491, HD36079, R01 HD031491]; NIGMS NIH HHS [GM08613, T32 GM008613] NR 35 TC 83 Z9 83 U1 0 U2 1 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 AUG 3 PY 1999 VL 96 IS 16 BP 9258 EP 9263 DI 10.1073/pnas.96.16.9258 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 223HL UT WOS:000081835500088 PM 10430930 ER PT J AU Schneider, JM Anders, A Brown, IG Hjorvarsson, B Hultman, L AF Schneider, JM Anders, A Brown, IG Hjorvarsson, B Hultman, L TI Temporal development of the plasma composition of a pulsed aluminum plasma stream in the presence of oxygen SO APPLIED PHYSICS LETTERS LA English DT Article ID CHARGE-STATE DISTRIBUTIONS; VACUUM-ARC; GAS AB We describe the temporal development of the plasma composition of pulsed aluminum plasma streams at various oxygen pressures. The plasma was formed with a vacuum arc plasma source and the time resolved plasma composition was measured with time-of-flight charge-to-mass spectrometry. The temporal development of the plasma composition as well as the Al average ion charge state was found to be a strong function of the oxygen pressure. Oxygen and hydrogen concentrations of up to 0.36 and 0.32, respectively, were found in the first 50 mu s of the pulse at oxygen pressures of greater than or equal to 5x10(-5) Torr. The average charge state of aluminum ions was found to vary from +1.2 to +2.5 depending on the oxygen pressure and the time elapsed after ignition of the arc. These results are of fundamental importance for the understanding of the evolution of the composition (through the plasma composition) and microstructure (through the Al ion flux energy) of alumina thin films produced by pulsed, reactive aluminum plasmas. (C) 1999 American Institute of Physics. [S0003-6951(99)01231-0]. C1 Linkoping Univ, Dept Phys, Thin Film Phys Div, S-58183 Linkoping, Sweden. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Royal Inst Technol, Dept Mat Phys, KTH, S-10044 Stockholm, Sweden. RP Schneider, JM (reprint author), Linkoping Univ, Dept Phys, Thin Film Phys Div, S-58183 Linkoping, Sweden. RI Schneider, Jochen/A-4701-2012; Hjorvarsson, Bjorgvin/B-3022-2011; Anders, Andre/B-8580-2009; OI Anders, Andre/0000-0002-5313-6505; Hjorvarsson, Bjorgvin/0000-0003-1803-9467 NR 12 TC 28 Z9 28 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 2 PY 1999 VL 75 IS 5 BP 612 EP 614 DI 10.1063/1.124457 PG 3 WC Physics, Applied SC Physics GA 220BF UT WOS:000081644100006 ER PT J AU Snodgrass, JW Meffe, GK AF Snodgrass, JW Meffe, GK TI Habitat use and temporal dynamics of blackwater stream fishes in and adjacent to beaver ponds SO COPEIA LA English DT Article ID MULTIPLE SPATIAL SCALES; POPULATION-DYNAMICS; LANDSCAPE; ASSEMBLAGE; COMMUNITIES; INTEGRITY; FRAMEWORK; POSITION AB We sampled stream fishes within and at varying distances from beaver ponds for two years in two southeastern blackwater streams. Our objectives were to determine whether species showed ontogenetic or seasonal shifts in habitat use involving impounded and free-flowing stream reaches and whether assemblage structure and dynamics varied between ponds and streams and as a function of upstream distance from ponds. Age-0 and adults of most of the more abundant species (15) were collected in either streams or ponds, suggesting no ontogenetic or seasonal shifts in habitat use for these species; The proportions of age-0 to adult fish of four species were higher in ponds than streams, suggesting movement of adults to ponds to breed. The proportion of age-0 to adult Erimyzon oblongus was higher in streams when compared to ponds, suggesting adults of this species supplement food re sources by feeding in ponds. Assemblage structure was less stable in ponds when compared to streams. In streams, age-0 and adult fish densities and population coefficients of variation (cv) declined with upstream distance from ponds. Because high CVs were typical of species occurring in streams throughout their life, and habitat structure and variability were not related to upstream distance from ponds, interactions between pond boundaries and fish movement are probably responsible for the patterns we observed in streams adjacent to ponds. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Rutgers State Univ, Environm & Occupat Hlth Sci Inst, CRESP, Piscataway, NJ 08855 USA. RP Snodgrass, JW (reprint author), Univ Georgia, Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. RI Snodgrass, Joel/C-5288-2016; OI Snodgrass, Joel/0000-0002-4436-8750 NR 37 TC 11 Z9 11 U1 0 U2 6 PU AMER SOC ICHTHYOLOGISTS HERPETOLOGISTS PI CHARLESTON PA UNIV CHARLESTON, GRICE MARINE LABORATORY, 205 FORT JOHNSON RD, CHARLESTON, SC 29412 USA SN 0045-8511 J9 COPEIA JI Copeia PD AUG 2 PY 1999 IS 3 BP 628 EP 639 DI 10.2307/1447595 PG 12 WC Zoology SC Zoology GA 227HR UT WOS:000082075500007 ER PT J AU Schultz, DL AF Schultz, DL TI Population structure, reproduction, and lipid cycling in the dusky shiner (Notropis cummingsae) in contrasting streams SO COPEIA LA English DT Article ID LIFE-HISTORY TRAITS; GAMBUSIA-HOLBROOKI; PHENOTYPIC PLASTICITY; EASTERN MOSQUITOFISH; FISH; SIZE; AGE; EVOLUTION; SURVIVAL; SALMON AB To document the reproductive aml lipid cycle of the dusky shiner, and to determine how environmental differences can influence patterns of reproduction and lipid storage, I sampled dusky shiners from January 1989 to June 1991 from two streams in west central South Carolina Upper Three Runs and Four Mile Creek. The streams were chosen because of likely differences in primary productivity. Sex, ovary mass, reproductive stage, somatic dry mass, and lipid mass were quantified, as appropriate, for all individuals sampled. There were many differences between the two streams that suggested shiners in Four Mile Creek had greater resource availability during most years, including greater monthly growth, larger ovaries, a longer spawning season, and higher maximum somatic lipid level. In both streams, females accumulated lipid prior to ovarian enlargement and depleted lipid through a spawning season that spanned three or four months. Males accumulated and depleted lipid in a pattern similar to that seen in females but not to the same extent. There was no apparent lipid accumulation or depletion in immature individuals. There was a clear temporal relationship between lipid accumulation and ovarian enlargement. Lipid accumulation appears to be a prerequisite for reproduction. Lipid accumulation in fall appears to be facultative and not a prerequisite for winter survival. Size-specific differences in reproductive performance appear to be the product of size-specific differences in lipid storage. Large adults became rare in late summer when lipid levels were low. The differences between the two populations are consistent with the theoretical expectation that greater resource availability favors earlier maturation and greater allocation to reproduction. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Schultz, DL (reprint author), Nicholls State Univ, Dept Biol Sci, Thibodaux, LA 70310 USA. NR 28 TC 4 Z9 5 U1 0 U2 4 PU AMER SOC ICHTHYOLOGISTS HERPETOLOGISTS PI CHARLESTON PA UNIV CHARLESTON, GRICE MARINE LABORATORY, 205 FORT JOHNSON RD, CHARLESTON, SC 29412 USA SN 0045-8511 J9 COPEIA JI Copeia PD AUG 2 PY 1999 IS 3 BP 669 EP 683 PG 15 WC Zoology SC Zoology GA 227HR UT WOS:000082075500011 ER PT J AU Masiero, A Murayama, H AF Masiero, A Murayama, H TI Can epsilon '/epsilon be supersymmetric? SO PHYSICAL REVIEW LETTERS LA English DT Article ID CHANGING NEUTRAL CURRENTS; STANDARD MODEL; FCNC; QCD AB Supersymmetric contributions to epsilon(I)/epsilon have been generally regarded as small. We point out, however, that this is based on specific assumptions, such as universal scalar mass, and in general need not be true. Based on (1) hierarchical quark Yukawa matrices protected by flavor symmetry, (2) generic dependence of Yukawa matrices on Polonyi/moduli fields as expected in many supergravity/superstring theories, (3) Cabibbo rotation originating from the down-sector, and (4) phases of order unity, we find the typical supersymmetric contribution to epsilon(I)/epsilon to be of order 3 x 10(-3) for m((q) over bar) = 500 GeV, possibly dominating the reported KTeV Collaboration value epsilon(I)/epsilon = (28 +/- 4.1) X 10(-4). If so, the neutron electric dipole moment is likely to be within the reach of the currently planned experiments. C1 SISSA, I-34014 Trieste, Italy. Ist Nazl Fis Nucl, Sez Trieste, Trieste, Italy. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Masiero, A (reprint author), SISSA, Via Beirut 2-4, I-34014 Trieste, Italy. RI Murayama, Hitoshi/A-4286-2011 NR 25 TC 122 Z9 122 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 2 PY 1999 VL 83 IS 5 BP 907 EP 910 DI 10.1103/PhysRevLett.83.907 PG 4 WC Physics, Multidisciplinary SC Physics GA 223BT UT WOS:000081820400005 ER PT J AU Sosa, M Berisso, MC Christian, DC Felix, J Gara, A Gottschalk, E Gutierrez, G Hartouni, EP Knapp, BC Kreisler, MN Lee, S Markianos, K Moreno, G Reyes, MA Wang, M Wehmann, A Wesson, D AF Sosa, M Berisso, MC Christian, DC Felix, J Gara, A Gottschalk, E Gutierrez, G Hartouni, EP Knapp, BC Kreisler, MN Lee, S Markianos, K Moreno, G Reyes, MA Wang, M Wehmann, A Wesson, D TI Spin-parity analysis of the centrally produced (KSK +/-)-K-0 pi(-/+) system at 800 GeV/c SO PHYSICAL REVIEW LETTERS LA English DT Article ID PARTICLE PHYSICS; 85 GEV/C; MESON AB Results are presented from an analysis of a large sample of centrally produced mesons in the reaction pp --> p(slow) (K(s)(0)K(+/-)pi(+/-))p(fast) with 800 GeV/c protons incident on liquid hydrogen. Two resonances dominate the final state, the f(1)(1285), decaying into a(0)pi, and the f(1)(1420), decaying into K*K. Both mesons are produced with equal amounts of /J(z)/(eta) = 1(+/-), and no J(z) = 0. C1 Univ Guanajuato, Leon, Guanajuato, Mexico. Univ Massachusetts, Amherst, MA 01003 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Columbia Univ, Nevis Labs, Irvington, NY 10533 USA. RP Univ Guanajuato, Leon, Guanajuato, Mexico. NR 20 TC 6 Z9 6 U1 3 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 2 PY 1999 VL 83 IS 5 BP 913 EP 916 DI 10.1103/PhysRevLett.83.913 PG 4 WC Physics, Multidisciplinary SC Physics GA 223BT UT WOS:000081820400007 ER PT J AU Alavi-Harati, A Albuquerque, IF Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barker, AR Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, C Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hanagaki, K Hidaka, S Hsiung, YB Jejer, V Jennings, J Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL McManus, AP Mikelsons, P Monnier, E Nakaya, T Nauenberg, U Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Qiao, C Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Slater, W Solomey, N Somalwar, SV Stone, RL Suzuki, I Swallow, EC Swanson, RA Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Wu, JY Yamanaka, T Zimmerman, ED AF Alavi-Harati, A Albuquerque, IF Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barker, AR Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, C Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hanagaki, K Hidaka, S Hsiung, YB Jejer, V Jennings, J Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL McManus, AP Mikelsons, P Monnier, E Nakaya, T Nauenberg, U Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Qiao, C Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Slater, W Solomey, N Somalwar, SV Stone, RL Suzuki, I Swallow, EC Swanson, RA Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Wu, JY Yamanaka, T Zimmerman, ED TI Measurement of the decay K-L -> pi(0)gamma gamma SO PHYSICAL REVIEW LETTERS LA English DT Article ID K(L)->PI(0)GAMMA-GAMMA AB We report on a new measurement of the decay K-L --> pi(0)gamma gamma by the KTeV experiment at Fermilab. We determine the K-L --> pi(0)gamma gamma branching ratio to be (1.68 +/- 0.07 +/- 0.08) x 10(-6). Our data show the first evidence for a low-mass gamma gamma signal as predicted by recent O(p(6)) chiral perturbation calculations which include vector meson exchange contributions. From our data, we extract a value for the effective vector coupling a(V) = -0.72 +/- 0.05 +/- 0.06. C1 Univ Arizona, Tucson, AZ 85721 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Colorado, Boulder, CO 80309 USA. Elmhurst Coll, Elmhurst, IL 60126 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Osaka Univ, Toyonaka, Osaka 560, Japan. Rice Univ, Houston, TX 77005 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA. Univ Virginia, Inst Nucl & Particle Phys, Charlottesville, VA 22901 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Cheu, E (reprint author), Univ Arizona, Tucson, AZ 85721 USA. RI Albuquerque, Ivone/H-4645-2012 OI Albuquerque, Ivone/0000-0001-7328-0136 NR 11 TC 42 Z9 42 U1 0 U2 0 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 AUG 2 PY 1999 VL 83 IS 5 BP 917 EP 921 DI 10.1103/PhysRevLett.83.917 PG 5 WC Physics, Multidisciplinary SC Physics GA 223BT UT WOS:000081820400008 ER PT J AU Alavi-Harati, A Albuquerque, IF Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barker, AR Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, C Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hanagaki, K Hidaka, S Hsiung, YB Jejer, V Jennings, J Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL McManus, AP Mikelsons, P Monnier, E Nakaya, T Nauenberg, U Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Qiao, C Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Slater, W Solomey, N Somalwar, SV Stone, RL Suzuki, I Swallow, EC Swanson, RA Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Wu, JY Yamanaka, T Zimmerman, ED AF Alavi-Harati, A Albuquerque, IF Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barker, AR Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, C Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hanagaki, K Hidaka, S Hsiung, YB Jejer, V Jennings, J Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL McManus, AP Mikelsons, P Monnier, E Nakaya, T Nauenberg, U Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Qiao, C Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Slater, W Solomey, N Somalwar, SV Stone, RL Suzuki, I Swallow, EC Swanson, RA Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Wu, JY Yamanaka, T Zimmerman, ED TI Measurement of the branching ratio of pi(0) -> e(+)e(-) using K-L -> 3 pi(0) decays in flight SO PHYSICAL REVIEW LETTERS LA English DT Article ID RADIATIVE-CORRECTIONS; PI(0)->E(+)E(-); PI-0->E+E AB The branching ratio of the rare decay pi(0) --> e(+)e(-) has been measured in E799-II, a rare kaon decay experiment using the KTeV detector at Fermilab. We observed 275 candidate pi(0) --> e(+)e(-) events, with an expected background of 21.4 +/- 6.2 events which includes the contribution from Dalitz decays. We measured B[pi(0) --> e(+)e(-), (m(e+e-)/m(pi 0))(2) > 0.95] = (6.09 +/- 0.40 +/- 0.24) X 10(-8), where the first error is statistical and the second systematic. This result is the first significant observation of the excess rate for this decay above the unitarity lower bound. C1 Univ Arizona, Tucson, AZ 85721 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Colorado, Boulder, CO 80309 USA. Elmhurst Coll, Elmhurst, IL 60126 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Osaka Univ, Toyonaka, Osaka 560, Japan. Rice Univ, Houston, TX 77005 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA. Univ Virginia, Inst Nucl & Particle Phys, Charlottesville, VA 22901 USA. Univ Wisconsin, Madison, WI 53706 USA. RP Zimmerman, ED (reprint author), Columbia Univ, New York, NY 10027 USA. RI Albuquerque, Ivone/H-4645-2012 OI Albuquerque, Ivone/0000-0001-7328-0136 NR 16 TC 13 Z9 13 U1 0 U2 0 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 AUG 2 PY 1999 VL 83 IS 5 BP 922 EP 925 DI 10.1103/PhysRevLett.83.922 PG 4 WC Physics, Multidisciplinary SC Physics GA 223BT UT WOS:000081820400009 ER PT J AU Aggarwal, MM Agnihotri, A Ahammed, Z Angelis, ALS Antonenko, V Arefiev, V Astakhov, V Avdeitchikov, V Awes, TC Baba, PVKS Badyal, SK Baldine, A Barabach, L Barlag, C Bathe, S Batiounia, B Bernier, T Bhalla, KB Bhatia, VS Blume, C Bock, R Bohne, EM Borocz, ZK Bucher, D Buijs, A Busching, H Carlen, L Chalyshev, V Chattopadhyay, S Cherbatchev, R Chujo, T Claussen, A Das, AC Decowski, MP Delagrange, H Djordjadze, V Donni, P Doubovik, I Dutt, S Majumdar, MRD El Chenawi, K Eliseev, S Enosawa, K Foka, P Fokin, S Frolov, V Ganti, MS Garpman, S Gavrishchuk, O Geurts, FJM Ghosh, TK Glasow, R Gupta, SK Guskov, B Gustafsson, HA Gutbrod, HH Higuchi, R Hrivnacova, I Ippolitov, M Kalechofsky, H Kamermans, R Kampert, KH Karadjev, K Karpio, K Kato, S Kees, S Kim, H Kolb, BW Kosarev, I Koutcheryaev, I Krumpel, T Kugler, A Kulinich, P Kurata, M Kurita, K Kuzmin, N Langbein, I Lebedev, A Lee, YY Lohner, H Luquin, L Mahapatra, DP Manko, V Martin, M Martinez, G Maximov, A Mehdiyev, R Mgebrichvili, G Miake, Y Mikhalev, D Mir, MF Mishra, GC Miyamoto, Y Morrison, D Mukhopadhyay, DS Myalkovski, V Naef, H Nandi, BK Nayak, SK Nayak, TK Neumaier, S Nianine, A Nikitine, V Nikolaev, S Nilsson, P Nishimura, S Nomokonov, P Nystrand, J Obenshain, FE Oskarsson, A Otterlund, I Pachr, M Parfenov, A Pavliouk, S Peitzmann, T Petracek, V Plasil, F Pinganaud, W Purschke, ML Raeven, B Rak, J Raniwala, R Raniwala, S Ramamurthy, VS Rao, NK Retiere, F Reygers, K Roland, G Rosselet, L Roufanov, I Roy, C Rubio, JM Sako, H Sambyal, SS Santo, R Sato, S Schlagheck, H Schmidt, HR Schutz, Y Shabratova, G Shah, TH Sibiriak, I Siemiarczuk, T Silvermyr, D Sinha, BC Slavine, N Soderstrom, I Solomey, N Sorensen, SP Stankus, P Stefanek, G Steinberg, P Stenlund, E Stuken, D Sumbera, M Svensson, T Trivedi, MD Tsvetkov, A Tykarski, L Urbahn, J von der Pijll, EC von Eijndhoven, N von Nieuwenhuizen, GJ Vinogradov, A Viyogi, YP Vodopianov, A Voros, S Wyslouch, B Yagi, K Yokota, Y Young, GR AF Aggarwal, MM Agnihotri, A Ahammed, Z Angelis, ALS Antonenko, V Arefiev, V Astakhov, V Avdeitchikov, V Awes, TC Baba, PVKS Badyal, SK Baldine, A Barabach, L Barlag, C Bathe, S Batiounia, B Bernier, T Bhalla, KB Bhatia, VS Blume, C Bock, R Bohne, EM Borocz, ZK Bucher, D Buijs, A Busching, H Carlen, L Chalyshev, V Chattopadhyay, S Cherbatchev, R Chujo, T Claussen, A Das, AC Decowski, MP Delagrange, H Djordjadze, V Donni, P Doubovik, I Dutt, S Majumdar, MRD El Chenawi, K Eliseev, S Enosawa, K Foka, P Fokin, S Frolov, V Ganti, MS Garpman, S Gavrishchuk, O Geurts, FJM Ghosh, TK Glasow, R Gupta, SK Guskov, B Gustafsson, HA Gutbrod, HH Higuchi, R Hrivnacova, I Ippolitov, M Kalechofsky, H Kamermans, R Kampert, KH Karadjev, K Karpio, K Kato, S Kees, S Kim, H Kolb, BW Kosarev, I Koutcheryaev, I Krumpel, T Kugler, A Kulinich, P Kurata, M Kurita, K Kuzmin, N Langbein, I Lebedev, A Lee, YY Lohner, H Luquin, L Mahapatra, DP Manko, V Martin, M Martinez, G Maximov, A Mehdiyev, R Mgebrichvili, G Miake, Y Mikhalev, D Mir, MF Mishra, GC Miyamoto, Y Morrison, D Mukhopadhyay, DS Myalkovski, V Naef, H Nandi, BK Nayak, SK Nayak, TK Neumaier, S Nianine, A Nikitine, V Nikolaev, S Nilsson, P Nishimura, S Nomokonov, P Nystrand, J Obenshain, FE Oskarsson, A Otterlund, I Pachr, M Parfenov, A Pavliouk, S Peitzmann, T Petracek, V Plasil, F Pinganaud, W Purschke, ML Raeven, B Rak, J Raniwala, R Raniwala, S Ramamurthy, VS Rao, NK Retiere, F Reygers, K Roland, G Rosselet, L Roufanov, I Roy, C Rubio, JM Sako, H Sambyal, SS Santo, R Sato, S Schlagheck, H Schmidt, HR Schutz, Y Shabratova, G Shah, TH Sibiriak, I Siemiarczuk, T Silvermyr, D Sinha, BC Slavine, N Soderstrom, I Solomey, N Sorensen, SP Stankus, P Stefanek, G Steinberg, P Stenlund, E Stuken, D Sumbera, M Svensson, T Trivedi, MD Tsvetkov, A Tykarski, L Urbahn, J von der Pijll, EC von Eijndhoven, N von Nieuwenhuizen, GJ Vinogradov, A Viyogi, YP Vodopianov, A Voros, S Wyslouch, B Yagi, K Yokota, Y Young, GR TI Freeze-out parameters in central 158A (GeVPb)-Pb-208+Pbcollisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; NUCLEAR COLLISIONS; EXPANSION AB Neutral pion production in central 158A GeV Pb-208 + Pb-208 collisions has been studied in the WA98 experiment at the CERN Super Proton Synchrotron. The pi(0) transverse mass spectrum has been analyzed in terms of a thermal model with hydrodynamic expansion. The high accuracy and large kinematic coverage of the measurement allow one to limit previously noted ambiguities in the extracted freeze-out parameters. The results are shown to be sensitive to the shape of the velocity distribution at freeze-out. C1 Panjab Univ, Chandigarh 160014, India. Univ Rajasthan, Jaipur 302004, Rajasthan, India. Bhabha Atom Res Ctr, Ctr Variable Energy Cyclotron, Calcutta 700064, W Bengal, India. Univ Geneva, CH-1211 Geneva 4, Switzerland. RRC Kurchatov Inst, RU-123182 Moscow, Russia. Dubna Joint Nucl Res Inst, RU-141980 Dubna, Russia. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Jammu, Jammu 180001, India. Univ Munster, D-48149 Munster, Germany. Ecole Mines, SUBATECH, Nantes, France. Gesell Schwerionenforsch GmbH, D-64220 Darmstadt, Germany. Univ Utrecht, NIKHEF, NL-3508 TA Utrecht, Netherlands. Univ Lund, SE-22100 Lund, Sweden. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Inst Phys Nucl, CZ-25068 Rez, Czech Republic. Inst Nucl Studies, NL-9747 AA Groningen, Netherlands. Univ Groningen, KVI, NL-9747 AA Groningen, Netherlands. Inst Nucl Studies, PL-00681 Warsaw, Poland. MIT, Cambridge, MA 02139 USA. Inst Phys, Bhubaneswar 751005, Orissa, India. Univ Tennessee, Knoxville, TN 37966 USA. RP Aggarwal, MM (reprint author), Panjab Univ, Chandigarh 160014, India. RI Decowski, Patrick/A-4341-2011; Peitzmann, Thomas/K-2206-2012; Mehdiyev, Rashid/H-6299-2013; Lohner, Herbert/B-2397-2014; Sumbera, Michal/O-7497-2014 OI Peitzmann, Thomas/0000-0002-7116-899X; Lohner, Herbert/0000-0002-7441-739X; Sumbera, Michal/0000-0002-0639-7323 NR 20 TC 23 Z9 23 U1 0 U2 1 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 AUG 2 PY 1999 VL 83 IS 5 BP 926 EP 930 DI 10.1103/PhysRevLett.83.926 PG 5 WC Physics, Multidisciplinary SC Physics GA 223BT UT WOS:000081820400010 ER PT J AU Melechko, AV Braun, J Weitering, HH Plummer, EW AF Melechko, AV Braun, J Weitering, HH Plummer, EW TI Two-dimensional phase transition mediated by extrinsic defects SO PHYSICAL REVIEW LETTERS LA English DT Article ID CHARGE-DENSITY-WAVE; SI(001) SURFACE; SN/GE(111) AB We have investigated the (root 3 x root 3) to (3 x 3) phase transition in the a phase of Sn/Ge(111) with variable temperature STM at temperatures between 30 and 300 K. Point defects in the Sn film stabilize localized regions of the (3 x 3) phase, where the size is characterized by a temperature dependent length (exponential attenuation). The inverse of the attenuation length is a linear function of temperature showing that the phase transition occurs at 70 K. At low temperature a density wave mediated defect-defect interaction realigns the defects to be in registry with the (3 x 3) domains. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Melechko, AV (reprint author), Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RI Melechko, Anatoli/B-8820-2008 NR 20 TC 71 Z9 71 U1 0 U2 11 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 AUG 2 PY 1999 VL 83 IS 5 BP 999 EP 1002 DI 10.1103/PhysRevLett.83.999 PG 4 WC Physics, Multidisciplinary SC Physics GA 223BT UT WOS:000081820400028 ER PT J AU Miyakawa, N Zasadzinski, JF Ozyuzer, L Guptasarma, P Hinks, DG Kendziora, C Gray, KE AF Miyakawa, N Zasadzinski, JF Ozyuzer, L Guptasarma, P Hinks, DG Kendziora, C Gray, KE TI Predominantly superconducting origin of large energy gaps in underdoped Bi2Sr2CaCu2O8+delta from tunneling spectroscopy SO PHYSICAL REVIEW LETTERS LA English DT Article ID OVERDOPED BI2SR2CACU2O8+DELTA; BEHAVIOR; DENSITY; WAVE AB New tunneling data are reported in Bi2Sr2CaCu2O8+delta which show quasiparticle excitation gaps, a, reaching values as high as 60 meV for underdoped crystals with T-c = 70 K. These energy gaps are nearly 3 times larger than those of overdoped crystals with similar T-c. Despite the large differences in gap magnitude, the tunneling spectra display qualitatively similar characteristics over the entire doping range. Detailed examination of the spectra, including the Josephson IcRn product measured in break junctions, indicates that these energy gaps are predominantly of superconducting origin. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Sci Univ Tokyo, Dept Appl Phys, Shinjuku Ku, Tokyo 1628601, Japan. IIT, Chicago, IL 60616 USA. Izmir Inst Technol, Dept Phys, TR-35230 Izmir, Turkey. USN, Res Lab, Washington, DC 20375 USA. RP Miyakawa, N (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Ozyuzer, Lutfi/H-3142-2011 NR 24 TC 185 Z9 187 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 AUG 2 PY 1999 VL 83 IS 5 BP 1018 EP 1021 DI 10.1103/PhysRevLett.83.1018 PG 4 WC Physics, Multidisciplinary SC Physics GA 223BT UT WOS:000081820400033 ER PT J AU de la Figuera, J Pohl, K Schmid, AK Bartelt, NC Hrbek, J Hwang, RQ AF de la Figuera, J Pohl, K Schmid, AK Bartelt, NC Hrbek, J Hwang, RQ TI Multiplication of threading dislocations in strained metal films under sulfur exposure SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 14th International Vacuum Congress/10th International Conference on Solid Surfaces/5th International Conference on Nanometre-Scale Science and Technology/10th International Conference on Quantitative Surface Analysis CY AUG 31-SEP 04, 1998 CL BIRMINGHAM, ENGLAND SP British Vacuum Council, Inst Phys, Int Union Vacuum Sci Tech & Applicat DE copper; dislocation multiplication; ruthenium; scanning tunneling microscopy; strained metal films; sulfur; threading dislocations ID RECONSTRUCTION; INTERFACES; SURFACES; CU(111) AB Strained thin films often contain ordered networks of misfit dislocations which can determine their chemical and mechanical properties. We consider the reaction of sulfur with two-monolayer films of Cu on Ru(0001). These films contain a network of parallel partial dislocations, separating regions of fcc and hcp stacking, with threading edge dislocations where partial dislocations meet. Sulfur reacts with the threading dislocations and dissociates them. The increase in the threading dislocation density is accommodated by modifying the dislocation network. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP de la Figuera, J (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. EM juan@io.ca.sandia.gov RI Hrbek, Jan/I-1020-2013; de la Figuera, Juan/E-7046-2010 OI de la Figuera, Juan/0000-0002-7014-4777 NR 16 TC 9 Z9 9 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 2 PY 1999 VL 433 BP 93 EP 98 DI 10.1016/S0039-6028(99)00060-6 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 230DA UT WOS:000082235500018 ER PT J AU Pohl, K de la Figuera, J Bartelt, MC Bartelt, NC Hrbek, J Hwang, RQ AF Pohl, K de la Figuera, J Bartelt, MC Bartelt, NC Hrbek, J Hwang, RQ TI Thermal vibrations of a two-dimensional vacancy island crystal in a strained metal film SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 14th International Vacuum Congress/10th International Conference on Solid Surfaces/5th International Conference on Nanometre-Scale Science and Technology/10th International Conference on Quantitative Surface Analysis CY AUG 31-SEP 04, 1998 CL BIRMINGHAM, ENGLAND SP British Vacuum Council, Inst Phys, Int Union Vacuum Sci Tech & Applicat DE lattice vibrations; nanostructures; ruthenium; scanning tunneling microscopy; self-organization; silver; sulfur; two-dimensional solids ID SCANNING TUNNELING MICROSCOPE; PERIODIC DOMAIN-STRUCTURES; EPITAXIAL-GROWTH; SURFACES; AU(111); MANIPULATION; RU(0001); AG(111); COBALT; MOTION AB Vacancy islands formed during room-temperature exposure to sulfur of a submonolayer Ag him on Ru(0001) order spontaneously to form a triangular lattice at an island area fraction just above 20%. A normal mode decomposition of the thermal vibrations of this vacancy island crystal, measured with time-resolved scanning tunneling microscopy, obtains Lame coefficients in the range of 10(8) N m(-2). We show that these estimates are consistent with stabilizing forces derived from long-range elastic interactions between the islands. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Pohl, K (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. EM karsten@io.ca.sandia.gov RI Hrbek, Jan/I-1020-2013; de la Figuera, Juan/E-7046-2010 OI de la Figuera, Juan/0000-0002-7014-4777 NR 29 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 2 PY 1999 VL 433 BP 506 EP 511 DI 10.1016/S0039-6028(99)00130-2 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 230DA UT WOS:000082235500100 ER PT J AU Ledieu, J Munz, AW Parker, TM McGrath, R Diehl, RD Delaney, DW Lograsso, TA AF Ledieu, J Munz, AW Parker, TM McGrath, R Diehl, RD Delaney, DW Lograsso, TA TI Structural study of the five-fold surface of the Al70Pd21Mn9 quasicrystal SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 14th International Vacuum Congress/10th International Conference on Solid Surfaces/5th International Conference on Nanometre-Scale Science and Technology/10th International Conference on Quantitative Surface Analysis CY AUG 31-SEP 04, 1998 CL BIRMINGHAM, ENGLAND SP British Vacuum Council, Inst Phys, Int Union Vacuum Sci Tech & Applicat DE alloys; scanning tunneling microscope ID ENERGY-ELECTRON DIFFRACTION; QUASI-CRYSTALLINE COATINGS; AL68PD23MN9; ALPDMN; LEED; STM AB We report an investigation of the five-fold surface of the Al70Pd21Mn9 quasicrystal using STM, LEED and AES. Surfaces sputtered and annealed to 875 K showed excellent five-fold symmetric LEED patterns, and STM revealed cluster-like protrusions. Surfaces sputtered and annealed to 1050 K also showed sharp LEED patterns but here STM showed flat surfaces which could be imaged with atomic resolution. AES indicated these annealed surfaces were Mn deficient. Threshold analysis of images of the flat surfaces shows that the surface call be generated by tiling with pentagons. Large protrusions on the flat surfaces were found where the pentagonal tiling breaks down. Angles between these protrusions were found to match angles present in the stereographic projection of the icosahedral group . (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Liverpool, Surface Sci Res Ctr, Liverpool L69 3BX, Merseyside, England. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP McGrath, R (reprint author), Univ Liverpool, Surface Sci Res Ctr, POB 147, Liverpool L69 3BX, Merseyside, England. EM mcgrath@liv.ac.uk RI McGrath, Ronan/A-1568-2009; Ledieu, Julian/F-1430-2010 OI McGrath, Ronan/0000-0002-9880-5741; NR 17 TC 33 Z9 33 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 2 PY 1999 VL 433 BP 666 EP 671 DI 10.1016/S0039-6028(99)00144-2 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 230DA UT WOS:000082235500132 ER PT J AU Dumas, P Hein, M Otto, A Persson, BNJ Rudolf, P Raval, R Williams, GP AF Dumas, P Hein, M Otto, A Persson, BNJ Rudolf, P Raval, R Williams, GP TI Friction of molecules at metallic surfaces: experimental approach using synchrotron infrared spectroscopy SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 14th International Vacuum Congress/10th International Conference on Solid Surfaces/5th International Conference on Nanometre-Scale Science and Technology/10th International Conference on Quantitative Surface Analysis CY AUG 31-SEP 04, 1998 CL BIRMINGHAM, ENGLAND SP British Vacuum Council, Inst Phys, Int Union Vacuum Sci Tech & Applicat DE alkali metals; carbon monoxide; chemisorption; copper; electrical transport (conductivity, resistivity; mobility, etc.); friction; fullerenes; gold; infrared absorption spectroscopy; low index single crystal surfaces; silver; solid-gas interfaces; vibrations of adsorbed molecules ID CHARGE-TRANSFER; ABSORPTION SPECTROSCOPY; INVERSE-PHOTOEMISSION; ELECTRONIC-STRUCTURE; ADSORBED LAYERS; C-60; RESISTIVITY; ADSORPTION; CU(111); CO AB Adsorbate dynamics has received increasing interest over the last years, as it has been realized that the electron dynamics of the substrate can be profoundly affected by adsorbates due to couplings between vibrational and electronic states. Persson has developed a model where the scattering of the conduction electrons by the adsorbate results in a friction force between the adsorbate and the metallic substrate. The model predicts that the dipole-forbidden low-frequency adsorbate modes exhibit anti-absorption peaks, and that the broadband infrared (IR) reflectance change displays a characteristic frequency dependence in the anomalous skin-effect region, with an asymptotic limit in the mid-IR. The friction coefficient, which can be extracted from the asymptotic change of the reflectance, equals the inverse of the electronic contribution to the lifetime of the frustrated parallel translation. This model has been verified by recording simultaneously the direct-current (DC) resistance change, the broadband IR reflectance change and the IR features for various adsorbates on Cu(111) thin films epitaxially grown on TiO2(110) substrates. The friction coefficients obtained from the DC resistance change and from the IR reflectance change show good agreement. Coadsorption experiments reveal the marked dependence of the friction coefficient on the adsorbate-induced density of states at the Fermi level (E-F). Using the Newns-Anderson model for chemisorption, the IR reflectance change of C-60 adsorbed on the following noble metal surfaces: Ag(111), Au(110) and Cu(100), indicates a high density of induced states at E-F. (C) 1999 Elsevier Science B.V, All rights reserved. C1 Ctr Univ Paris Sud, LURE, F-91405 Orsay, France. Univ Dusseldorf, Lehrstuhl Oberflachenwissensch IPkM, D-40225 Dusseldorf, Germany. Forschungszentrum Julich, Inst Festkorperforsch, D-52425 Julich, Germany. Fac Univ Notre Dame Paix, LISE, B-5000 Namur, Belgium. Univ Liverpool, Dept Chem, Leverhulme Ctr & IRC Surface Sci, Liverpool L69 3BX, Merseyside, England. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Dumas, P (reprint author), Ctr Univ Paris Sud, LURE, F-91405 Orsay, France. EM pdumas@lure.u-psud.fr RI Persson, Bo Nils Johan/I-1548-2013; Rudolf, Petra/E-6434-2014 OI Persson, Bo Nils Johan/0000-0003-1535-738X; Rudolf, Petra/0000-0002-4418-1769 NR 42 TC 15 Z9 15 U1 1 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD AUG 2 PY 1999 VL 433 BP 797 EP 805 DI 10.1016/S0039-6028(99)00166-1 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 230DA UT WOS:000082235500157 ER PT J AU Carter, PH Mitlitsky, F Weisberg, AH Whitehead, JC Humble, RW AF Carter, PH Mitlitsky, F Weisberg, AH Whitehead, JC Humble, RW TI Design trade space for a Mars ascent vehicle for a Mars sample return mission SO ACTA ASTRONAUTICA LA English DT Article AB The design of an ascent vehicle for Mars sample return is one of the most challenging problems to be addressed for this type of mission. This paper identifies the spectrum of performance requirements that could be required of a Mars ascent vehicle for a sample return mission. With this understanding of performance requirements, an investigation of technology requirements is presented. These technology requirements are compared to past and existing technology in order to identify which are the lagging technologies and where development investment should be made. Mars ascent approaches which include storable propellants and in-situ production of propellants are considered. Several technology comparisons are performed to illustrate performance regions that are appropriate for different technologies. Several promising propulsion technologies are identified: miniature constant displacement pumps, bladder lined composite tankage, thin wall metal tankage and advanced propellants. Technologies that have been designed, built, tested and flown are emphasized. (C) 1999 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Carter, PH (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 7 TC 1 Z9 1 U1 5 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD AUG-NOV PY 1999 VL 45 IS 4-9 BP 311 EP 318 DI 10.1016/S0094-5765(99)00148-4 PG 8 WC Engineering, Aerospace SC Engineering GA 263XT UT WOS:000084151100015 ER PT J AU Whitehead, JC Guernsey, CS AF Whitehead, JC Guernsey, CS TI Mars ascent propulsion on a minimum scale SO ACTA ASTRONAUTICA LA English DT Article AB A concept is presented for a single stage vehicle intended to lift a Mars sample to an orbital rendezvous. At 200 kg liftoff mass, it can potentially be delivered by a Mars Pathfinder size aeroshell. Based on launch vehicle design principles, propellants are pumped from thin-walled low pressure tanks into compact high pressure thrusters; Technical risk is reduced by using non-cryogenic propellants,:and by driving piston pumps with heated helium. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Whitehead, JC (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 3 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD AUG-NOV PY 1999 VL 45 IS 4-9 BP 319 EP 327 DI 10.1016/S0094-5765(99)00149-6 PG 9 WC Engineering, Aerospace SC Engineering GA 263XT UT WOS:000084151100016 ER PT J AU Ontko, JS AF Ontko, JS TI Multivariate fractional efficiency SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article AB The fractional efficiency of any particle separator operating on arbitrary particulate distributions is defined in this article. Some consequences of this definition for the interpretation of experimental data are examined using an example. These considerations show that the customary assumptions should not be made,without critically scrutinizing data to which they are supposed to apply. C1 US DOE, Fed Energy Technol Ctr, Morgantown, WV 26505 USA. RP Ontko, JS (reprint author), US DOE, Fed Energy Technol Ctr, 3610 Collins Ferry Rd, Morgantown, WV 26505 USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD AUG-SEP PY 1999 VL 31 IS 2-3 BP 194 EP 197 DI 10.1080/027868299304246 PG 4 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 229GA UT WOS:000082184100006 ER PT J AU Collins, LA Magee, NH Bryant, HC Zeilik, M AF Collins, LA Magee, NH Bryant, HC Zeilik, M TI A conference experience for undergraduates SO AMERICAN JOURNAL OF PHYSICS LA English DT Article AB Programs launched by many universities and the federal government expose many undergraduate students in the physical sciences to research early in their careers. However, in their research experiences, undergraduates are not usually introduced to the modes by which scientific knowledge, which they may have helped gather, is communicated and evaluated by working scientists. Nor is it always made clear where the research frontiers really lie. To this end, we guided a selected group of undergraduates through a national scientific conference, followed by a week of tutorials and discussions to help them better understand what had transpired. The program complemented the basic undergraduate research endeavors by emphasizing the importance of disseminating results both to other scientists and to society in general, Tutors and discussion leaders in the second week were experts in their fields and included some of the invited speakers from the main meeting. A considerable improvement in the understanding of the issues and prospects for a career in physics was discernible among the students after their two-week experience. (C) 1999 American Association of Physics Teachers. C1 Univ Calif Los Alamos Natl Lab, Grp T4, MS B212, Los Alamos, NM 87545 USA. Univ New Mexico, Albuquerque, NM 87131 USA. RP Collins, LA (reprint author), Univ Calif Los Alamos Natl Lab, Grp T4, MS B212, POB 1663, Los Alamos, NM 87545 USA. NR 14 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 USA SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD AUG PY 1999 VL 67 IS 8 BP 685 EP 691 DI 10.1119/1.19353 PG 7 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA 219FP UT WOS:000081597500008 ER PT J AU Akiyama, J Volik, SV Plajzer-Frick, I Prince, A Sago, H Weier, HUG Vanderbilt, JN Hawgood, S Poulain, FR AF Akiyama, J Volik, SV Plajzer-Frick, I Prince, A Sago, H Weier, HUG Vanderbilt, JN Hawgood, S Poulain, FR TI Characterization of the mouse collectin gene locus SO AMERICAN JOURNAL OF RESPIRATORY CELL AND MOLECULAR BIOLOGY LA English DT Article ID MANNOSE-BINDING PROTEIN; EXON STRUCTURE REVEALS; IN-SITU HYBRIDIZATION; PULMONARY SURFACTANT; EVOLUTIONARY RELATIONSHIP; SERINE-PROTEASE; CLASSICAL PATHWAY; INNATE IMMUNITY; MANNAN-BINDING; A GENE AB Three of the four known mouse collectin genes have been mapped to chromosome 14. To further characterize the spatial relationship of these genes, a bacterial artificial chromosome (BAC) library of mouse chromosome 14 was screened using mouse surfactant protein (SP)-A and -D complementary DNAs (cDNAs). One large clone hybridized to both SP-A and SP-D cDNAs and was found by polymerase chain reaction (PCR) to contain sequences from one of the mouse mannose-binding lectin genes (Mb11), We used Southern mapping and subcloning of overlapping restriction fragments to characterize the gene locus. Mapping was confirmed by fluorescent in situ hybridization of fiber-stretched BAC DNA and by Southern hybridization of restriction endonuclease-digested and PCR-amplified genomic DNA. We found that the SP-A, Mb11, and SP-D genes reside contiguously within a 55-kb region. The SP-A and Mb11 genes are in the same 5' to 3' orientation and 16 kb apart. The SP-D gene is in the opposite orientation to the two other collectin genes, 13 kb away from the 3' end of the Mb11 gene The mouse SP-D gene had not previously been characterized. We found its size (13 kb) and organization to be similar to that of human SP-D. Exon I is untranslated. The second exon is a hybrid exon that contains signal for initiation of translation, signal peptide, N-terminal domain, and the first seven collagen triplets of the collagen-like domain of the protein. Four short exons (III through VI) encode the collagen-like domain of the protein, and exons VII and VIII the linking and the carbohydrate-recognition domains, respectively. C1 Univ Calif San Francisco, Cardiovasc Res Inst, San Francisco, CA 94118 USA. Univ Calif San Francisco, Dept Pediat, San Francisco, CA 94118 USA. Lawrence Berkeley Lab, Berkeley, CA USA. RP Poulain, FR (reprint author), Univ Calif San Francisco, Cardiovasc Res Inst, San Francisco, CA 94118 USA. FU NHLBI NIH HHS [HL-58047, HL-02834, HL-24075] NR 40 TC 16 Z9 16 U1 0 U2 1 PU AMER LUNG ASSOC PI NEW YORK PA 1740 BROADWAY, NEW YORK, NY 10019 USA SN 1044-1549 J9 AM J RESP CELL MOL JI Am. J. Respir. Cell Mol. Biol. PD AUG PY 1999 VL 21 IS 2 BP 193 EP 199 PG 7 WC Biochemistry & Molecular Biology; Cell Biology; Respiratory System SC Biochemistry & Molecular Biology; Cell Biology; Respiratory System GA 227JF UT WOS:000082076800009 PM 10423401 ER PT J AU Grate, JW Egorov, OB Fiskum, SK AF Grate, JW Egorov, OB Fiskum, SK TI Automated extraction chromatographic separations of actinides using separation-optimized sequential injection techniques SO ANALYST LA English DT Article ID INDUCTIVELY-COUPLED PLASMA; FLOW-INJECTION; NUCLEAR WASTE; MASS-SPECTROMETRY; PRECONCENTRATION; AMERICIUM; SAMPLES; COLUMN; TC-99 AB A sequential injection (SI) separation system has been developed for automated analytical separations of actinides using an actinide specific extraction chromatographic material (TRU-resin, Eichrom Industries, Inc., USA). On-line liquid scintillation counting was used to observe eluting species during method development, and fraction collection and alpha energy analysis were used for quantification. Several procedures for individual and group actinide elution are demonstrated and discussed, including elution of actinides as a single group; elution as groups based on valence state; selective separation of Pu using on-column redox chemistry; selective separation of Th; and various sequential actinide elution schemes. Eluent solution compositions and reagent chemistries were investigated with regard to elution peak shapes, selectivity, recoveries, carryover, and suitability for rapid automated procedures. The SI separation methods described serve as the basis for an automated actinide separation work station. An automated actinide separation procedure has been applied towards the analysis of Am, Cm, and Pu isotopes in three types of aged nuclear waste samples. Results from automated analytical separations followed by quantification by alpha spectroscopy were in good agreement with results obtained using manual separation techniques. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Pacific NW Natl Lab, Radiochem Proc Lab, Richland, WA 99352 USA. RP Grate, JW (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. NR 34 TC 34 Z9 36 U1 1 U2 9 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0003-2654 J9 ANALYST JI Analyst PD AUG PY 1999 VL 124 IS 8 BP 1143 EP 1150 DI 10.1039/a902579k PG 8 WC Chemistry, Analytical SC Chemistry GA 225UX UT WOS:000081984500003 ER PT J AU Yeung, ES AF Yeung, ES TI Following single cell fluorescence SO ANALYTICAL CHEMISTRY LA English DT Article ID INDUCED NATIVE FLUORESCENCE; ADRENAL-MEDULLARY CELLS; IDENTIFIED LEECH NEURONS; BOVINE CHROMAFFIN CELLS; CAPILLARY ELECTROPHORESIS; IMAGING MICROSCOPY; TRANSMITTER RELEASE; MASS-SPECTROMETRY; EXOCYTOSIS; SECRETION C1 Iowa State Univ, Ames, IA 50011 USA. US DOE, Washington, DC 20585 USA. RP Yeung, ES (reprint author), Iowa State Univ, Ames, IA 50011 USA. NR 50 TC 22 Z9 22 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 1999 VL 71 IS 15 BP 522A EP 529A PG 8 WC Chemistry, Analytical SC Chemistry GA 224BW UT WOS:000081877100008 PM 10450144 ER PT J AU Shaffer, SA Tolmachev, A Prior, DC Anderson, GA Udseth, HR Smith, RD AF Shaffer, SA Tolmachev, A Prior, DC Anderson, GA Udseth, HR Smith, RD TI Characterization of an improved electrodynamic ion funnel interface for electrospray ionization mass spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID PRINCIPLES AB An improved electrodynamic ion funnel for ion focusing at high pressure (>1 Torr) has been developed for a triple quadrupole mass spectrometer and its performance compared with that of an earlier prototype previously reported. The ion funnel consists of a series of ring electrodes of progressively smaller interval diameters to which rf and de electric potentials are co-applied, The new design utilizes ring electrodes possessing larger internal diameters that taper down to a relatively larger exit aperture. in the 1-10 Torr pressure range, the new design provides significant improvement in low m/z ion transmission. Additionally, the overall ion transmission range is improved by linked scanning of the ion funnel's rf voltage concomitantly with the scanning of the quadrupole mass analyzer. Transmission of a noncovalent complex through the interface demonstrated that excessive ion heating was not problematic. Computer simulations of ion transport support the ion funnel design and help explain the relative performance of both designs. Both ion simulations and experimental results are in accord and indicate close to 100% ion transmission efficiency for electrosprayed biopolymer ions through the interface and into the mass analyzer. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. EM rd-smith@pnl.gov RI Shaffer, Scott/F-8650-2010; Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 17 TC 106 Z9 109 U1 6 U2 47 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 AUG 1 PY 1999 VL 71 IS 15 BP 2957 EP 2964 DI 10.1021/ac990346w PG 8 WC Chemistry, Analytical SC Chemistry GA 224BW UT WOS:000081877100016 PM 10450147 ER PT J AU Hierlemann, A Ricco, AJ Bodenhofer, K Gopel, W AF Hierlemann, A Ricco, AJ Bodenhofer, K Gopel, W TI Effective use of molecular recognition in gas sensing: Results from acoustic wave and in situ FT-IR measurements SO ANALYTICAL CHEMISTRY LA English DT Article ID THICKNESS-SHEAR MODE; VOLATILE ORGANIC-COMPOUNDS; CHEMICAL SENSOR ARRAYS; PATTERN-RECOGNITION; SUPRAMOLECULAR CHEMISTRY; CHIRAL DISCRIMINATION; EXTERNAL REFLECTION; SOLVENT VAPORS; SURFACE; DEVICES AB To probe directly the analyte/film interactions that characterize molecular recognition in gas sensors, we recorded changes to the in situ surface vibrational spectra of specifically functionalized surface acoustic wave (SAW) devices concurrently with analyte exposure and SAW measurement of the extent of sorption. Fourier transform infrared external-reflectance spectra (FT-IR-ERS) were collected from operating 97-MHz SAW delay lines during exposure to a range of analytes as they interacted with thin-film coatings previously shown to be selective: cyclodextrins for chiral recognition, nickel camphorates for Lewis bases such as pyridine or organophosphonates, and phthalocyanines far aromatic compounds. In most cases where specific chemical interactions-metal coordination, "cage" compound inclusion, or pi-stacking-were expected, analyte dosing caused distinctive changes in the IR spectra, together with anomalously large SAW sensor responses. In contrast, control experiments involving the physisorption of the same analytes by conventional organic polymers did not cause similar changes in the IR spectra, and the SAW responses were smaller. For a given conventional polymer, the partition coefficients (or SAW sensor signals) roughly followed the analyte fraction of saturation vapor pressure. These SAW/FT-IR results support earlier conclusions derived from thickness-shear mode resonator data. C1 Sandia Natl Labs, Microsensor Res & Dev Dept, Albuquerque, NM 87185 USA. Univ Tubingen, Inst Theoret & Phys Chem, D-72076 Tubingen, Germany. RP Hierlemann, A (reprint author), ETH Honggerberg, IQE, Phys Elect Lab, HPT-H4-2, CH-8093 Zurich, Switzerland. RI Hierlemann, Andreas/A-7046-2008; Ricco, Antonio/A-5273-2010 OI Ricco, Antonio/0000-0002-2355-4984; Hierlemann, Andreas/0000-0002-3838-2468; NR 56 TC 56 Z9 61 U1 3 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 1999 VL 71 IS 15 BP 3022 EP 3035 DI 10.1021/ac981311j PG 14 WC Chemistry, Analytical SC Chemistry GA 224BW UT WOS:000081877100025 PM 10450152 ER PT J AU Chen, X Fei, ZD Smith, LM Bradbury, EM Majidi, V AF Chen, X Fei, ZD Smith, LM Bradbury, EM Majidi, V TI Stable-isotope-assisted MALDI-TOF mass spectrometry for accurate determination of nucleotide compositions of PCR products SO ANALYTICAL CHEMISTRY LA English DT Article ID POLYMERASE CHAIN-REACTION; NUCLEIC-ACIDS; HUMAN DNA; BASE COMPOSITION; HUMAN-GENOME; POLYMORPHISMS; SEQUENCE; DIAGNOSIS; STRAND; GENE AB In parallel with a large-scale sequencing effort, the human genome project will need next-generation tools for accurate and efficient analyses of the enormous pool of DNA sequences. Such analyses are required for (a) validation of DNA sequences, (b) comparison of a parent (known) sequence with a related (unknown) sequence, and (c) characterization of sequence polymorphisms in various genes, especially those associated with genetically inherited human diseases. Here, we report a novel method that combines stable isotope C-13/N-15 labeling of PCR products of the target sequences with analysis of the mass shifts by mass spectrometry (MS). The mass shift due to the labeling of a single type of nucleotide (i.e., A, T, G, or C) reveals the number of that type of nucleotide in a given DNA fragment. Using this technique, we have accurately determined nucleotide compositions of DNA fragments. The method has also been applied to score a known single-nucleotide polymorphism (SNP), The comparisons of nucleotide compositions determined by our method among homologous sequences are useful in sequence validation, sequence comparison, and characterizations of sequence polymorphisms. C1 Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. Univ Wisconsin, Dept Chem, Madison, WI 53706 USA. Univ Calif Los Alamos Natl Lab, LSDO, Los Alamos, NM 87545 USA. Univ Calif Davis, Sch Med, Dept Biol Chem, Davis, CA 95616 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Chen, X (reprint author), Univ Calif Los Alamos Natl Lab, Div Life Sci, LS-8, Los Alamos, NM 87545 USA. NR 31 TC 27 Z9 28 U1 2 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 1999 VL 71 IS 15 BP 3118 EP 3125 DI 10.1021/ac9812680 PG 8 WC Chemistry, Analytical SC Chemistry GA 224BW UT WOS:000081877100037 PM 10450157 ER PT J AU Hang, W Yan, XM Wayne, DM Olivares, JA Harrison, WW Majidi, V AF Hang, W Yan, XM Wayne, DM Olivares, JA Harrison, WW Majidi, V TI Glow discharge source interfacing to mass analyzers: Theoretical and practical considerations SO ANALYTICAL CHEMISTRY LA English DT Article ID ELEMENTAL ANALYSIS; SPECTROMETRY; DYNAMICS; DENSITY; GAS AB The fundamental requirements for the optimum mechanical interface between a glow discharge ion source and a mass spectrometer are described in this paper. Specifically, the properties of a typical glow discharge ion source are compared and contrasted to those of a typical inductively coupled plasma ion source. The critical parameters and theoretical considerations of glow discharge and inductively coupled plasma ion source interfaces are reviewed, and the results of experiments using both quadrupole and time-of-flight mass spectrometers with a glow discharge source are presented. The experimental results clarify several important problems in the glow discharge ion sampling process. Our findings indicate that a shock wave structure does not occur in the supersonic expansion of the glow discharge ion source. Ions of different masses have similar initial kinetic energies in the glow discharge; thus, the angle of the skimmer cone is not a critical parameter for efficient ion beam extraction. Another consquence is that space charge effects in glow discharge ion sources repel heavy ions farther off axis than light ions. Thus, there are distinct and fundamental differences between glow discharge and inductively coupled plasma ion sources which are relevant to both ion sampling and ion ex-traction processes. C1 Univ Calif Los Alamos Natl Lab, Nucl Mat & Technol Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Univ Florida, Dept Chem, Gainesville, FL 32611 USA. RP Wayne, DM (reprint author), Univ Calif Los Alamos Natl Lab, Nucl Mat & Technol Div, NMT-1,MS G740, Los Alamos, NM 87545 USA. NR 37 TC 20 Z9 24 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 1999 VL 71 IS 15 BP 3231 EP 3237 DI 10.1021/ac9810922 PG 7 WC Chemistry, Analytical SC Chemistry GA 224BW UT WOS:000081877100053 PM 21662912 ER PT J AU Jacobson, SC Ermakov, SV Ramsey, JM AF Jacobson, SC Ermakov, SV Ramsey, JM TI Minimizing the number of voltage sources and fluid reservoirs for electrokinetic valving in microfluidic devices SO ANALYTICAL CHEMISTRY LA English DT Article ID MICROCHIP CAPILLARY ELECTROPHORESIS; OPEN-CHANNEL ELECTROCHROMATOGRAPHY; SEPARATIONS; SYSTEMS; CHROMATOGRAPHY; CHIPS AB A microchip gated valve is demonstrated that uses a single voltage source and three fluid reservoirs. The fluidic valve is a cross intersection, and the channels are dimensioned to perform the appropriate voltage division, simplifying the voltage control hardware. A single voltage source is applied directly to the sample reservoir and through a high-voltage relay to the buffer reservoir, and the waste reservoir is grounded. The volume of sample dispensed is determined by the duration that the high-voltage relay is open. Volumetric reproducibility is demonstrated to be <0.5% relative standard deviation for volumes of greater than or equal to 20 pL. The valve is tested for the minimum applied voltage necessary for leakage-free operation, i.e., sample diffusing from the cross intersection into the analysis channel. Moreover, appropriate channel dimensions are used to minimize the number of fluid reservoirs allowing effluent from the analysis and waste channels to be combined into a single reservoir. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Jacobson, SC (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Kipke, Daryl/A-2167-2009 NR 25 TC 82 Z9 84 U1 1 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 1999 VL 71 IS 15 BP 3273 EP 3276 DI 10.1021/ac990059s PG 4 WC Chemistry, Analytical SC Chemistry GA 224BW UT WOS:000081877100059 PM 21662916 ER PT J AU Macnaughton, SJ Stephen, JR Venosa, AD Davis, GA Chang, YJ White, DC AF Macnaughton, SJ Stephen, JR Venosa, AD Davis, GA Chang, YJ White, DC TI Microbial population changes during bioremediation of an experimental oil spill SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID GEL-ELECTROPHORESIS ANALYSIS; 16S RIBOSOMAL-RNA; COMMUNITY STRUCTURE; FATTY-ACIDS; ECOLOGY; SUBSURFACE; DIVERSITY; BIOMARKER; TOXICITY; BIOMASS AB Three crude oil bioremediation techniques were applied in a randomized block field experiment simulating a coastal oil spill. Four treatments (no oil control, oil alone, oil plus nutrients, and oil plus nutrients plus an indigenous inoculum) were applied. In situ microbial community structures were monitored by phospholipid fatty acid (PLFA) analysis and 16S rDNA PCR-denaturing gradient gel electrophoresis (DGGE) to (i) identify the bacterial community members responsible for the decontamination of the site and (ii) define an end point for the removal of the hydrocarbon substrate. The results of PLFA analysis demonstrated a community shift in all plots from primarily eukaryotic biomass to gram-negative bacterial biomass with time. PLFA profiles from the oiled plots suggested increased gram-negative biomass and adaptation to metabolic stress compared to unoiled controls. DGGE analysis of untreated control plots revealed a simple, dynamic dominant population structure throughout the experiment. This banding pattern disappeared in all oiled plots, indicating that the structure and diversity of the dominant bacterial community changed substantially. No consistent differences were detected between nutrient-amended and indigenous inoculum-treated plots, but both differed from the oil-only plots. Prominent bands were excised for sequence analysis and indicated that oil treatment encouraged the growth of gram-negative microorganisms within the alpha-proteobacteria and Flexibacter-Cytophaga-Bacteroides phylum. alpha-Proteobacteria were never detected in unoiled controls. PLFA analysis indicated that by week 14 the microbial community structures of the oiled plots were becoming similar to those of the unoiled controls from the same time point, but DGGE analysis suggested that major differences in the bacterial communities remained. C1 US EPA, Cincinnati, OH 45268 USA. Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37932 USA. Microbial Insights Inc, Rockford, TN 37853 USA. Oak Ridge Natl Lab, Div Biol Sci, Oak Ridge, TN 37831 USA. RP Venosa, AD (reprint author), US EPA, 26 W Martin Luther King Dr, Cincinnati, OH 45268 USA. RI reddy, indra/C-5363-2011 NR 38 TC 370 Z9 395 U1 10 U2 281 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD AUG PY 1999 VL 65 IS 8 BP 3566 EP 3574 PG 9 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 223WR UT WOS:000081865000046 PM 10427050 ER PT J AU Jellison, GE AF Jellison, GE TI Windows in ellipsometry measurements SO APPLIED OPTICS LA English DT Article ID 2-MODULATOR GENERALIZED ELLIPSOMETRY; MUELLER MATRIX; OPTICAL FUNCTIONS; FOURIER-ANALYSIS; CALIBRATION AB The effect of windows or lenses placed between the polarization-state generator and the polarization-state detector in a general ellipsometry measurement is examined. It is found that three parameters are required for describing the effects of the window retardation on the? ellipsometry measurements. Two of these window parameters can be measured at the same time as the sample parameters if the sample is isotropic, but the third window parameter cannot be determined independently and must be measured separately. If the sample is anisotropic, then none of the windows parameters can be measured independently at the same time as the sample parameters. An example is given in which the strain-induced retardation in fused-silica focusing lenses is measured with a two-modulator generalized ellipsometer and the results are used to correct the sample data. (C) 1999 Optical Society of America. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Jellison, GE (reprint author), Oak Ridge Natl Lab, Div Solid State, Bldg 3025 MS 6030,POB 2008, Oak Ridge, TN 37831 USA. EM jellisongejr@ornl.gov NR 20 TC 15 Z9 15 U1 1 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD AUG 1 PY 1999 VL 38 IS 22 BP 4784 EP 4789 DI 10.1364/AO.38.004784 PG 6 WC Optics SC Optics GA 224MC UT WOS:000081902000007 PM 18323967 ER PT J AU Buscher, CT Donohoe, RJ Mecklenburg, SL Berg, JM Tait, CD Huchton, KM Morris, DE AF Buscher, CT Donohoe, RJ Mecklenburg, SL Berg, JM Tait, CD Huchton, KM Morris, DE TI Raman spectroscopic study of the aging and nitration of actinide processing anion-exchange resins in concentrated nitric SO APPLIED SPECTROSCOPY LA English DT Article DE Raman spectroscopy; ion-exchange resins; actinide processing; plutonium nitrate ID LIQUID AB Degradation of two types of anion exchange resins, Dowex 11 and Reillex HPQ, from the action of concentrated nitric acid (4 to 12 M) and radiolysis [from depleted uranium as UO22+ nitrate species and Pu-239 as Pu(IV) nitrate species] was followed as a function of time with Raman vibrational spectroscopy. Elevated temperatures (similar to 50 degrees C) were used in the absence of actinide metal loading to simulate longer exposures of the resin to a HNO3 process stream and waste storage conditions. In the absence of actinide loading, only minor changes in the Dowex resin at acid concentrations less than or equal to 10 M were observed, while at 12 M acid concentration, the emergence of a Raman peak at 1345 cm(-1) indicates the addition of nitro functional groups to the resin, Similar studies with the Reillex resin show it to be more resistant to nitric acid attack at all acid concentrations. Incorporation of weakly radioactive depleted uranium as the UO22+ nitrate species to the ion-exchange sites of Dowex 11 under differing nitric acid concentrations (6 to 12 M) at room temperature showed no Raman evidence of resin degradation or nitration, even after several hundred days of contact. In contrast, Raman spectra for Dowex 11 in the presence of Pu-239 as Pu(IV) nitrate species reveal numerous changes indicating resin alterations, including a new mode at 1345 cm(-1) consistent with a Pu(IV)-nitrate catalyzed addition of nitro groups to the resin backbone. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Glen T Seaborg Inst Transactinium Sci, Los Alamos, NM 87545 USA. RP Morris, DE (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. RI Mecklenburg, Sandra/F-4571-2010; Morris, David/A-8577-2012 NR 44 TC 4 Z9 4 U1 1 U2 13 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD AUG PY 1999 VL 53 IS 8 BP 943 EP 953 DI 10.1366/0003702991947838 PG 11 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA 229KL UT WOS:000082193700009 ER PT J AU Kim, KH Kang, JS Choi, CK Lee, JY Olson, CG AF Kim, KH Kang, JS Choi, CK Lee, JY Olson, CG TI The electronic structures of epitaxial CrSi2 film prepared on Si(111) substrate SO APPLIED SURFACE SCIENCE LA English DT Article DE CrSi2; valence band; synchrotron radiation ID THIN-FILMS; SI-CR; SILICIDES; GROWTH; DISILICIDES; GAP AB The valence band (VB) electronic structures of CrSi2 were studied by synchrotron radiation photoemission. Overall features of the VB photoemission spectra measured at room temperature (RT) and 20 K by using synchrotron radiation. (photon energy, h nu = 20-130 eV) were similar. Two characteristic emissions were observed corresponding to the bonding and the nonbonding Cr-d partial density of states (PDOS) in the CrSi2. The onset of the VB photoemission measured at 20 K was located at about 0.32 eV below Fermi level, due to the energy band gap of CrSi2 more than 0.32 eV, (C) 1999 Elsevier Science B.V, All rights reserved. C1 Gyeongsang Natl Univ, Dept Phys, Chinju 660701, South Korea. Catholic Univ Korea, Dept Phys, Pucheon 422743, South Korea. Cheju Natl Univ, Dept Phys, Cheju 690702, South Korea. Korea Adv Inst Sci & Technol, Dept Elect Mat Sci, Daejeon 305701, South Korea. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Kim, KH (reprint author), Gyeongsang Natl Univ, Dept Phys, Chinju 660701, South Korea. RI Lee, Jeong Yong/C-8864-2011 NR 23 TC 4 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 150 IS 1-4 BP 8 EP 12 DI 10.1016/S0169-4332(99)00251-2 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 234FE UT WOS:000082473200002 ER PT J AU Manner, WL Lloyd, JA Hanrahan, RJ Paffett, MT AF Manner, WL Lloyd, JA Hanrahan, RJ Paffett, MT TI An examination of the initial oxidation of a uranium-base alloy (U-14.1 at.% Nb) by O-2 and D2O using surface-sensitive techniques SO APPLIED SURFACE SCIENCE LA English DT Article DE corrosion resistance; uranium; niobium ID X-RAY PHOTOELECTRON; AUGER-ELECTRON SPECTROSCOPY; WATER-VAPOR; DIOXIDE; NIOBIUM; XPS; AES AB The corrosion resistance of uranium is greatly enhanced by alloying with niobium. In this study the initial stages of corrosion of a specific uranium-base alloy (U-14.1 at.% Nb) by O-2 or D2O have been examined using the surface specific techniques of X-ray photoelectron spectroscopy (XPS), thermal programmed desorption (TPD), static secondary-ion mass spectroscopy (SSIMS), and sputtered neutrals mass spectroscopy (SNMS). XPS studies of the U -14.1 at.% Nb surface following oxidation using O-2 at 300 K indicate production of a thin oxide overlayer of stoichiometric UO2.0 intermixed with Nb2O5. The same stoichiometry is exhibited for uranium when the oxide is prepared at 500 K with O-2; although, niobium is much less oxidized exhibiting a mixture of NbO and Nb. Contrary to previous XPS literature, SNMS depth profiling studies reveal that oxidation by O-2 is much greater las judged by oxide layer thickness) than that exhibited by D2O. An oxide layer thickness of less than 20 Angstrom was created using D2O as an oxidant at 300 K with exposures > 3500 L (oxide layers created from O-2 are significantly greater at much smaller exposures). Formation of a critical density of Nb2O5 is suggested to be responsible for the enhanced corrosion resistance by preventing diffusion of O- (O2-) or OD-/OH- into the oxide/metal interface region. The domains of stability of hydroxyl formation have also been followed using TPD, SSIMS and XPS. Maximal surface hydroxyl concentrations (Theta(rel) = 0.30) are obtained at a surface temperature of 175 K for these experimental conditions. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Paffett, MT (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 47 TC 10 Z9 13 U1 2 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 150 IS 1-4 BP 73 EP 88 DI 10.1016/S0169-4332(99)00225-1 PG 16 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 234FE UT WOS:000082473200011 ER PT J AU Stoeffl, W Asoka-Kumar, P Howell, R AF Stoeffl, W Asoka-Kumar, P Howell, R TI The positron microprobe at LLNL SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 8th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces (SLOPOS-8) CY SEP 06-12, 1998 CL CAPE TOWN, SOUTH AFRICA DE positron microprobe; Lawrence Livermore National Laboratory; BaF2; crystals AB The electron linac-based positron source at Lawrence Livermore National Laboratory (LLNL) provides the world's highest current beam of keV positrons. We are building a positron microprobe that will produce a pulsed, focused positron beam for 3-dimensional scans of defect size and concentration with sub-micron resolution. The widely spaced and intense positron packets from the tungsten moderator at the end of the 100 MeV LLNL linac are captured and trapped in a magnetic bottle. The positrons are then released in 1 ns bunches at a 20 MHz repetition rate. With a three-stage re-moderation we will compress the cm-sized original beam to a 1 mu m diameter final spot on the target. The buncher will compress the arrival time of positrons on the target to less than 100 ps. A detector array with up to 60 BaF2 crystals in paired coincidence will measure the annihilation radiation with high efficiency and low background. The energy of the positrons can be varied from less than 1 keV up to 50 keV. The target can be instrumented to allow in situ annealing, cooling and stress. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Stoeffl, W (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 3 TC 21 Z9 21 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 149 IS 1-4 BP 1 EP 6 DI 10.1016/S0169-4332(99)00162-2 PG 6 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 233UH UT WOS:000082445300002 ER PT J AU White, MM Lessner, ES AF White, MM Lessner, ES TI A low-neutron background slow-positron source SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 8th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces (SLOPOS-8) CY SEP 06-12, 1998 CL CAPE TOWN, SOUTH AFRICA DE low-neutron background; slow-positron source; free-electron laser; advanced photon source AB The addition of a thermionic RF gun and a photocathode RF gun will allow the advanced photon source (APS) linear accelerator (linac) to become a free-electron laser (FEL) driver, As the FEL project progresses, the existing high-charge DC thermionic gun will no longer be critical to APS operation and could be used to generate high-energy or low-energy electrons to drive a slow-positron source. We investigated possibilities to create a useful low-energy source that could operate semi-independently and would have a low-neutron background. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP White, MM (reprint author), Argonne Natl Lab, ASD 401-B2178, Argonne, IL 60439 USA. EM mwhite@aps.anl.gov NR 11 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 149 IS 1-4 BP 20 EP 23 DI 10.1016/S0169-4332(99)00165-8 PG 4 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 233UH UT WOS:000082445300006 ER PT J AU Howell, RH Sterne, PA Hartley, J Cowan, TE AF Howell, RH Sterne, PA Hartley, J Cowan, TE TI High energy beam lifetime analysis SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 8th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces (SLOPOS-8) CY SEP 06-12, 1998 CL CAPE TOWN, SOUTH AFRICA DE electrostatic accelerator; high energy beam lifetime spectrometer; implantation time; annihilation time AB We have developed a positron lifetime defect analysis capability based on a 3 MeV electrostatic accelerator. The high energy beam lifetime spectrometer is operational with a 100 mCi Na-22 source providing a current of 5.5 x 10(5) positrons per second. Lifetime data are derived from a thin plastic transmission detector providing an implantation time and a BaF2 detector to determine the annihilation time. Positron lifetime analysis is performed with a 3 MeV positron beam on thick sample specimens at counting rates in excess of 2000 per second. The instrument is being used for bulk sample analysis and analysis of samples encapsulated in controlled environments for in situ measurements. (C) 1999 Elsevier Science B.V. All lights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Howell, RH (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Cowan, Thomas/A-8713-2011 OI Cowan, Thomas/0000-0002-5845-000X NR 1 TC 14 Z9 14 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 149 IS 1-4 BP 103 EP 105 DI 10.1016/S0169-4332(99)00181-6 PG 3 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 233UH UT WOS:000082445300021 ER PT J AU Cao, H Yuan, JP Zhang, R Sundar, CS Jean, YC Suzuki, R Ohdaira, T Nielsen, B AF Cao, H Yuan, JP Zhang, R Sundar, CS Jean, YC Suzuki, R Ohdaira, T Nielsen, B TI Free volumes and holes near the polymer surface studied by positron annihilation SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 8th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces (SLOPOS-8) CY SEP 06-12, 1998 CL CAPE TOWN, SOUTH AFRICA DE free volume; hole distribution; surface; polymer; polystyrene ID NEAR-THE-SURFACE; LIFETIME MEASUREMENTS; AMORPHOUS POLYMERS; GLASS-TRANSITION; SPECTROSCOPY; POLYSTYRENE; FILMS; DISTRIBUTIONS; COPOLYESTERS AB Positron annihilation lifetime and Doppler broadening of annihilation radiation experiments have been performed in a polystyrene film using the mono-energetic slow positron probe as a function of implantation energy. Significant variations of positron annihilation signals are observed at a short distance from the surface(less than or equal to 200 Angstrom). The ortho-positronium lifetime in the polymer increases near the surface, while its intensity decreases. The intensity results are interpreted in terms of a free-volume hole model for positronium formation. The lifetime results are interpreted as an expansion of local hole volume near the polymer surface. The free-volume and hole distribution near the surface is found to be broader than in the bulk. Applications of slow positrons to industrial problems, such as degradation of polymer coatings and membrane separations, are promising. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Missouri, Dept Chem, Kansas City, MO 64110 USA. Electrotech Lab, Tsukuba, Ibaraki 305, Japan. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11972 USA. RP Jean, YC (reprint author), Univ Missouri, Dept Chem, Kansas City, MO 64110 USA. RI Nielsen, Bent/B-7353-2009 OI Nielsen, Bent/0000-0001-7016-0040 NR 33 TC 30 Z9 32 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 149 IS 1-4 BP 116 EP 124 DI 10.1016/S0169-4332(99)00185-3 PG 9 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 233UH UT WOS:000082445300024 ER PT J AU Xu, J Mills, AP Suzuki, R Roth, EG Holland, RW AF Xu, J Mills, AP Suzuki, R Roth, EG Holland, RW TI Impurity-vacancy defects in implanted float-zone and Czochralski-Si SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 8th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces (SLOPOS-8) CY SEP 06-12, 1998 CL CAPE TOWN, SOUTH AFRICA DE defect engineering; impurity; implantation ID TRANSIENT ENHANCED DIFFUSION; POINT-DEFECTS; SILICON; TEMPERATURE; DEPENDENCE; POSITRONS; BORON AB The dual implantation method developed for defect engineering [O.W. Holland, L. Xie, B. Nelson, D.S. Zhou, J. Electron. Mater. 35 (199G) 99] uses an amorphizing implant in conjunction with high energy Si+-ion implantation to inject vacancies. Following annealing of the implanted samples for 20 min at 600 degrees C and at 800 degrees C, the amorphous layer recrystallizes by solid-phase epitaxial growth (SPEG), and the unwanted interstitials are consumed by recombination with vacancies. Doppler broadening of annihilation radiation and beam positron Lifetime measurements reveal that there are residual divacancy-impurity complexes formed in the SPEG layer. Since the effect is nearly identical in both float-zone and Czochralski-Si, the source of the impurities is not likely to be residual oxygen in the unimplanted crystals. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Electrotech Lab, Tsukuba, Ibaraki 305, Japan. RP Xu, J (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 17 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 149 IS 1-4 BP 193 EP 197 DI 10.1016/S0169-4332(99)00199-3 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 233UH UT WOS:000082445300038 ER PT J AU Hartley, JH Howell, RH Asoka-Kumar, P Sterne, PA Akers, D Denison, A AF Hartley, JH Howell, RH Asoka-Kumar, P Sterne, PA Akers, D Denison, A TI Positron annihilation studies of fatigue in 304 stainless steel SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 8th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces (SLOPOS-8) CY SEP 06-12, 1998 CL CAPE TOWN, SOUTH AFRICA DE stainless steel; fatigue; positron annihilation lifetime measurement AB Positron annihilation lifetime measurements were made on well calibrated fatigue samples of SS-304. Measurements were made on a high and low carbon alloy. Two separate lifetimes, indicating two defect site types were resolved in each sample. Significant Lifetime changes are observed to occur early in the fatigue cycles. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Lockheed Martin Idaho Technol, Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Denison, A (reprint author), Lockheed Martin Idaho Technol, Idaho Natl Engn & Environm Lab, MS-2214,POB 1625, Idaho Falls, ID 83415 USA. NR 6 TC 16 Z9 16 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 149 IS 1-4 BP 204 EP 206 DI 10.1016/S0169-4332(99)00201-9 PG 3 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 233UH UT WOS:000082445300040 ER PT J AU Ghosh, VJ Nielsen, B Kruseman, AC Mijnarends, PR van Veen, A Lynn, KG AF Ghosh, VJ Nielsen, B Kruseman, AC Mijnarends, PR van Veen, A Lynn, KG TI The effect of the detector resolution on the Doppler broadening measurements of both valence and core electron-positron annihilation SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 8th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces (SLOPOS-8) CY SEP 06-12, 1998 CL CAPE TOWN, SOUTH AFRICA DE Doppler broadening; momentum distribution; ratio curves; positron annihilation; coincidence measurement; two-detector; method ID ELEMENTAL SPECIFICITY AB The measured value of the Doppler profile of the electron-positron annihilation radiation depends on the resolution function of the detectors used in the experiment. This is illustrated by the results of calculations of the profile convoluted with resolution functions of different FWHM. These results are compared with Doppler broadening measurements for Al. The calculated results agree qualitatively with the experimental data. The positions of the peaks in the curves which give the ratio of a Doppler profile to a reference profile are found to shift towards higher momenta when the width of the resolution for the reference material was increased. Since the peaks in the ratio curves are used for identifying the chemical species, it is important that the peak positions be unambiguously characterized. Hence, the detector resolution should be carefully measured and quoted when reporting and comparing results of Doppler profiles. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. Delft Univ Technol, Inst Interfac Reactor, NL-2629 JB Delft, Netherlands. Washington State Univ, Ctr Mat Res, Pullman, WA 99163 USA. RP Ghosh, VJ (reprint author), Brookhaven Natl Lab, Div Mat Sci, Bldg 480, Upton, NY 11973 USA. RI Nielsen, Bent/B-7353-2009 OI Nielsen, Bent/0000-0001-7016-0040 NR 10 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 149 IS 1-4 BP 234 EP 237 DI 10.1016/S0169-4332(99)00207-X PG 4 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 233UH UT WOS:000082445300046 ER PT J AU Sterne, PA Pask, JE Klein, BM AF Sterne, PA Pask, JE Klein, BM TI Calculation of positron observables using a finite element-based approach SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 8th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces (SLOPOS-8) CY SEP 06-12, 1998 CL CAPE TOWN, SOUTH AFRICA DE finite element method; positron lifetimes; local density approximation; monovacancies; C-60; fuIlerenes ID ELECTRONIC-STRUCTURE CALCULATIONS; ANNIHILATION; SOLIDS; STATES AB We report the development of a new method for calculating positron observables using a finite-element approach for the solution of the Schrodinger equation. This method combines the advantages of both basis-set and real-space-grid approaches. The strict locality in real space of the finite element basis functions results in a method that is well suited for calculating large systems of a thousand or more atoms, as required for calculations of extended defects such as dislocations. In addition, the method is variational in nature and its convergence can be controlled systematically. The calculation of positron observables is very straightforward due to the real-space nature of this method. We illustrate the power of this method with positron lifetime calculations on defects and defect-fret materials, using overlapping atomic charge densities. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Sterne, PA (reprint author), Lawrence Livermore Natl Lab, POB 808,L-415, Livermore, CA 94550 USA. NR 19 TC 22 Z9 23 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 149 IS 1-4 BP 238 EP 243 DI 10.1016/S0169-4332(99)00208-1 PG 6 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 233UH UT WOS:000082445300047 ER PT J AU Moxom, J Schrader, DM Laricchia, G Hulett, LD Xu, J AF Moxom, J Schrader, DM Laricchia, G Hulett, LD Xu, J TI Fragmentation and ionization of CH(3)Cl by positron impact SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 8th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces (SLOPOS-8) CY SEP 06-12, 1998 CL CAPE TOWN, SOUTH AFRICA DE positron; molecule; fragmentation; methyl chloride ID ANNIHILATION; MOLECULES; ENERGY; H-2; HE AB The yields of positive ionic fragments produced by positron impact from CH(3)Cl have been studied in the energy range from threshold to 50 eV. The interactions take place whilst the positrons are stored in a Penning trap and the ions are detected using a rime of flight mass spectrometer. The cross-sections for production of the parent molecular ion and the fragment CH(3)(+) are presented. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37830 USA. Marquette Univ, Dept Chem, Milwaukee, WI 53201 USA. UCL, Dept Phys & Astron, London WC1E 6BT, England. RP Moxom, J (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Bldg 4500 S,MS 6142, Oak Ridge, TN 37830 USA. EM iyi@ornl.gov NR 19 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 149 IS 1-4 BP 244 EP 247 DI 10.1016/S0169-4332(99)00209-3 PG 4 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 233UH UT WOS:000082445300048 ER PT J AU Weber, MH Lynn, KG Denison, A AF Weber, MH Lynn, KG Denison, A TI Positron probing of quantum dots SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 8th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces (SLOPOS-8) CY SEP 06-12, 1998 CL CAPE TOWN, SOUTH AFRICA DE quantum dots; positron; broadening technique ID ANNIHILATION AB CdSe quantum dots (QDs) of different sizes were deposited as thin layers on glass slides and examined by positrons with the two detector coincident Doppler broadening technique (coPAS). Dots of 2.5 and 3.6 nm size were compared to the larger 4.4 nm size. It appears that the data on the smaller size (2.5 nm) display a shape consistent with positrons annihilating with electrons confined in the quantum dots. The next larger size is on the limit of QD behavior. The observed broadening in the annihilation line for the smallest size sample is consistent with annihilation with quantum-dot confined electrons. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Idaho Natl Lab, Lockheed Martin Idaho Technol, Idaho Falls, ID 83415 USA. Washington State Univ, Pullman, WA 99164 USA. RP Idaho Natl Lab, Lockheed Martin Idaho Technol, MS-2214,POB 1625, Idaho Falls, ID 83415 USA. EM and@inel.gov NR 8 TC 1 Z9 1 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 EI 1873-5584 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 149 IS 1-4 BP 264 EP 268 DI 10.1016/S0169-4332(99)00213-5 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 233UH UT WOS:000082445300052 ER PT J AU Hunt, AW Weber, MH Golovchenko, JA Lynn, KG AF Hunt, AW Weber, MH Golovchenko, JA Lynn, KG TI In flight positron annihilation in thin targets SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 8th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces (SLOPOS-8) CY SEP 06-12, 1998 CL CAPE TOWN, SOUTH AFRICA DE two quantum annihilation in flight; in flight positron annihilation; positron annihilation ID IN-FLIGHT; ELECTRON; SEARCH; RESONANCES AB We report on the first direct energy resolved measurements of two quantum annihilation in flight (TQAF) using monoenergetic positrons below 100 keV. A monoenergetic positron beam at Washington State University with variable kinetic energy up to 70 keV was guided onto thin aluminum targets. To clearly identify in flight positron annihilation a two dimensional Doppler broadening technique was employed utilizing two HPGe detectors. The method uniquely identifies TQAF by providing the total energy of the annihilating electron-positron pair. A basic understanding of the fundamental TQAF process has been obtained using this high resolution technique. With this fundamental understanding we believe several new avenues of experimental exploration are possible. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Harvard Univ, Dept Phys, Cambridge, MA 02138 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Washington State Univ, Dept Phys, Pullman, WA 99164 USA. Rowland Inst Sci Inc, Cambridge, MA 02142 USA. RP Hunt, AW (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 E Ave,L-280, Livermore, CA 94550 USA. NR 17 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD AUG PY 1999 VL 149 IS 1-4 BP 282 EP 286 DI 10.1016/S0169-4332(99)00216-0 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 233UH UT WOS:000082445300055 ER PT J AU Grossan, B Spillar, E Tripp, R Pirzkal, N Sutin, BM Johnson, P Barnaby, D AF Grossan, B Spillar, E Tripp, R Pirzkal, N Sutin, BM Johnson, P Barnaby, D TI An infrared search for extinguished supernovae in starburst galaxies SO ASTRONOMICAL JOURNAL LA English DT Article DE dust, extinction; galaxies : nuclei; galaxies : starburst; infrared radiation; instrumentation : miscellaneous; supernovae : general ID RADIO OBSERVATIONS; M82; DISCOVERY; NUCLEUS; RATES; NGC-6946; REMNANTS; EMISSION; DISTANCE; PROJECT AB IR and radio-band observations of heavily extinguished regions in starburst galaxies suggest a high supernova (SN) rate associated with such regions. Optically measured SN rates may therefore underestimate the total SN rate by factors of up to 10, as a result of the very high extinction (A(B) similar to 10-20 mag) to core-collapse SNe in starburst regions. The IR/radio SN rates come from a variety of indirect means, however, which suffer from model dependence and other problems. We describe a direct measurement of the SN rate from a regular patrol of starburst galaxies done with K'-band imaging to minimize the effects of extinction. A collection of K'-band measurements of core-collapse SNe near maximum light is presented. Such measurements (excluding 1987A) are not well reported in the literature. Results of a preliminary K'-band search, using the MIRC camera at the Wyoming Infrared Observatory and an improved search strategy using the new ORCA optics, are described. A monthly patrol of a sample of IRAS bright (mostly starburst) galaxies within 25 Mpc should yield 1-6 SNe yr,corresponding to the range of estimated SN rates. Our initial MIRC search with low resolution (2." 2 pixels) failed to find extinguished SNe in the IRAS galaxies, limiting the SN rate outside the nucleus (at greater than 15 " radius) to less than 3.8 far-IR SN rate units (SNe per century per 10(10) L-circle dot measured at 60 and 100 mu m, or FIRSRU) at 90% confidence. The MIRC camera had insufficient resolution to search nuclear starburst regions, where starburst and SN activity is concentrated; therefore, we were unable to rigorously test the hypothesis of high SN rates in heavily obscured star-forming regions. We conclude that high-resolution nuclear SN searches in starburst galaxies with small fields are more productive than low-resolution, large-held searches, even for our sample of large (often several arcminutes) galaxies. With our ORCA high-resolution optics, we could limit the total SN rate to less than 1.3 FIRSRU at 90% confidence in 3 years of observations, lower than most estimates. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Inst Nucl & Particle Phys, Berkeley, CA 94720 USA. Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. European So Observ, D-85748 Garching, Germany. Univ Calif Observ Lick Observ, Santa Cruz, CA 95064 USA. Univ Chicago, Yerkes Observ, Williams Bay, WI 53191 USA. RP Grossan, B (reprint author), Univ Calif Berkeley, Space Sci Lab, 1 Cyclotron Rd,Mail Stop 50-232, Berkeley, CA 94720 USA. NR 38 TC 18 Z9 18 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD AUG PY 1999 VL 118 IS 2 BP 705 EP 718 DI 10.1086/300962 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 232JZ UT WOS:000082368700010 ER PT J AU De Propris, R Stanford, SA Eisenhardt, PR Dickinson, M Elston, R AF De Propris, R Stanford, SA Eisenhardt, PR Dickinson, M Elston, R TI The K-band luminosity function in galaxy clusters to z similar to 1 SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : dusters : general; galaxies : evolution; galaxies : formation; galaxies : luminosity function, mass function ID PREDICTED STAR COUNTS; REDSHIFT SURVEY; FIELD GALAXIES; ELLIPTIC GALAXIES; DISTANT CLUSTERS; EVOLUTION; POPULATIONS; SPECTROSCOPY; MAGNITUDE; UNIVERSE AB present K-band luminosity functions for galaxies in a heterogeneous sample of 38 clusters at 0.1 < z < 1. Using infrared-selected galaxy samples, which generally reach 2 mag fainter than the characteristic galaxy luminosity LY*, we fitted Schechter functions to background-corrected cluster galaxy counts to determine K* as a function of redshift. Because of the magnitude limit of our data, the faint-end slope a is fixed at -0.9 in the fitting process. We find that K*(z) departs from no-evolution predictions at z > 0.4 and is consistent with the behavior of a simple, passive luminosity evolution model in which galaxies form all their stars in a single burst at z(f) = 2(3) in an H(0) = 65 km s(-1) Mpc(-1), Omega(M) = 0.3, Omega(A), = 0.7(0) universe. This differs from the flat or negative infrared luminosity evolution, which has been reported for high-redshift field galaxy samples. We find that the observed evolution appears to be insensitive to cluster X-ray luminosity or optical richness, implying little variation in the evolutionary history of galaxies over the range of environmental densities spanned by our cluster sample. These results support and extend previous analyses based on the color evolution of high-redshift cluster E/SO galaxies, indicating not only that their stellar populations formed at high-redshift, but that the assembly of the galaxies themselves was largely complete by z approximate to 1 and that subsequent evolution down to the present epoch was primarily passive. C1 Univ New S Wales, Sch Phys, Dept Astron & Opt, Sydney, NSW 2052, Australia. Univ Calif Davis, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. RP De Propris, R (reprint author), Univ New S Wales, Sch Phys, Dept Astron & Opt, Sydney, NSW 2052, Australia. EM propris@edwin.phys.unsw.edu.au; adam@igpp.llnl.gov; prme@kromos.jpl.nasa.gov; med@stsci.edu; elston@astro.ufl.edu NR 71 TC 111 Z9 111 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 AUG PY 1999 VL 118 IS 2 BP 719 EP 729 DI 10.1086/300978 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 232JZ UT WOS:000082368700011 ER PT J AU Siebert, J Leighly, KM Laurent-Muehleisen, SA Brinkmann, W Boller, T Matsuoka, M AF Siebert, J Leighly, KM Laurent-Muehleisen, SA Brinkmann, W Boller, T Matsuoka, M TI An ASCA observation of the radio-loud narrow-line Seyfert 1 galaxy RGB J0044+193 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : abundances; galaxies : individual :; RGB J0044+193; radio lines : general; X-rays : general ID ALL-SKY SURVEY; ACTIVE GALACTIC NUCLEI; FE-II; ACCRETION DISKS; QUASARS; IDENTIFICATIONS; EMISSION; SPECTRA AB Narrow-line Seyfert 1 galaxies are generally found to be radio-quiet and there was only one radio-loud object known so far (PKS 0558-504). Here we present the results of a 50 ksec ASCA observation of the recently discovered second radio-loud NLS1 galaxy RGB J0044+193. The X-ray data are complemented by radio observations and a new optical spectrum for this source. We find evidence for variable radio emission and an inverted radio spectrum of RGB J0044+193. The optical continuum turned out to be extremely blue. This may either indicate additional line emission, for example from Fe I, or scattering of a blue intrinsic continuum. The X-ray spectrum shows a clear break around 1.8 keV. Above this energy the spectrum is characterized by a power law with a photon index of Gamma approximate to 2.1. For energies below 2 keV the spectrum is much softer and it can either be modeled with a steeper power law (Gamma approximate to 2.7) or a blackbody component with a temperature around 0.2 keV. The X-ray count rate of the source decreased by a factor of two within one day and there is evidence for low amplitude variability on much shorter time scales. Given its average 2-10 keV X-ray luminosity of (1.35 +/- 0.05) x 10(44) erg s(-1), RGB J0044+193 is significantly more variable than a typical broad line Seyfert 1 galaxy of comparable X-ray luminosity, but consistent with the bulk of NLS1 galaxies. The spectral as well as the variability properties of RGB J0044+193 are indistinguishable from those of radio-quiet NLS1s. In particular, we find no evidence for a flat X-ray component due to inverse Compton emission related to the putative non-thermal radio emission from RGB J0044+193. We argue, however, that this does nut rule out a pole-on orientation for RGB J0044+193. C1 Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. RIKEN, Inst Phys & Chem Res, Wako, Saitama 35101, Japan. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. RP Siebert, J (reprint author), Max Planck Inst Extraterr Phys, Giessenbachstr, D-85740 Garching, Germany. EM jos@mpe.mpg.de NR 36 TC 33 Z9 33 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 AUG PY 1999 VL 348 IS 3 BP 678 EP 684 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 235ZV UT WOS:000082574500005 ER PT J AU Phillips, KJH Mewe, R Harra-Murnion, LK Kaastra, JS Beiersdorfer, P Brown, GV Liedahl, DA AF Phillips, KJH Mewe, R Harra-Murnion, LK Kaastra, JS Beiersdorfer, P Brown, GV Liedahl, DA TI Benchmarking the MEKAL spectral code with solar X-ray spectra SO ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES LA English DT Article DE atomic data; line : identification; sun : X-rays, gamma-rays; X-rays : general ID STELLAR CORONAE; SPECTROMETER; FLARE; LINES AB With the likelihood that high-resolution soft X-ray spectra of non-solar astronomical sources will soon become available, it is desirable to examine the accuracy of spectral synthesis codes. In this paper, a benchmark study of the MEKAL code, extensively used in the past for spectra from EUVE, ASCA, SAX, and other spacecraft, is presented using high-resolution solar flare X-ray spectra obtained with the Bragg Flat Crystal Spectrometer (FCS) on SMM. Lines in the range 5-20 Angstrom are used to adjust the wavelengths in the MEKAL code. Many of the lines are duc to Fe ions, and arise from 3-2 transitions for spectra obtained during the decay phase of one of the flares, while others arise from higher-excitation (4-2, 5-2 etc.) transitions for spectra obtained near the peak of a second flare. Laboratory measurements of the wavelengths of these lines were also used to confirm the SMM values as well as published identifications from the HULLAC atomic code. The adjustments needed were up to 35 m Angstrom for line wavelengths above 13 Angstrom but much less at shorter wavelengths. Some of these adjustments will be perceptible for spectra from the forthcoming SMM and Chandra spacecraft. C1 Rutherford Appleton Lab, Dept Space Sci, Didcot OX11 0QX, Oxon, England. SRON, Space Res Lab, NL-3584 CA Utrecht, Netherlands. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Lawrence Livermore Natl Lab, Dept Phys & Space Technol, Livermore, CA 94551 USA. RP Phillips, KJH (reprint author), Rutherford Appleton Lab, Dept Space Sci, Didcot OX11 0QX, Oxon, England. EM K.J.H.Phillips@rl.ac.uk OI Harra, Louise/0000-0001-9457-6200 NR 30 TC 56 Z9 57 U1 1 U2 1 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 0365-0138 J9 ASTRON ASTROPHYS SUP JI Astron. Astrophys. Suppl. Ser. PD AUG PY 1999 VL 138 IS 2 BP 381 EP 393 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 225XV UT WOS:000081992000014 ER PT J AU Mauche, CW AF Mauche, CW TI ORFEUS II and IUE spectroscopy of EX Hydrae SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; stars : individual (EX Hydrae); stars : magnetic fields; ultraviolet : stars; white dwarfs ID EMISSION-LINE RATIOS; WHITE-DWARF; CATACLYSMIC VARIABLES; AM-HERCULIS; NOVAE; STARS; HYA AB Using five high-resolution (lambda/Delta lambda approximate to 3000) FUV (910-1210 Angstrom) spectra acquired in 1996 December during the flight of the ORFEUS-SPAS II mission, 47 archival IUE short-wavelength UV (1150-1950 Angstrom) spectra, and archival EUVE deep survey photometry (70-200 Angstrom), we present a detailed picture of the behavior of the magnetic cataclysmic variable EX Hydrae in he vacuum ultraviolet. Like Hopkins Ultraviolet Telescope spectra of this source, these far-ultraviolet (FUV) and UV spectra reveal broad emission lines of He II, C II-CIV, N III and N V, O VI, Si III-S IV, and Al III superposed on a continuum that is blue in the UV and nearly flat in the FUV. Like ORFEUS spectra of AM Her, the O VI lambda lambda 1032, 1038 doublet is resolved into broad (FWHM approximate to 2000 km s(-1)) and narrow (FWHM approximate to 200 km s(-1)) emission components. Consistent with its behavior in the optical, and hence consistent with the accretion curtain model of this source, the FUV and UV continuum flux densities, the FUV and UV broad emission-line fluxes, and the radial velocity of the O VI broad emission component all vary on the spin phase of the white dwarf, with the maximum of the FUV and UV continuum and broad emission line flux light curves coincident with maximum blueshift of the broad O VI emission component. On the binary phase, the strong eclipse of the EW flux by the bulge on the edge of the accretion disk is accompanied by narrow and relatively weak absorption components of the FUV emission lines and 30%-40% eclipses of all the UV emission lines except He II lambda 1640, while the UV continuum is largely unaffected. Furthermore, both the flux and radial velocities of the O VI narrow emission component vary with binary phase. The relative phasing of the FUV and UV continuum light curves and the FUV emission-line radial velocities implicate the accretion funnel as the source of the FUV and UV continuum and the O vr broad emission component and implicate the white dwarf as the source of the O VI narrow emission component. Various lines of evidence imply that the density of both the broad- and narrow-line regions is n greater than or similar to 10(11) cm(-3), but the O VI line ratios imply that the narrow-line region is optically thick, while the broad-line region is more likely optically thin. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Mauche, CW (reprint author), Lawrence Livermore Natl Lab, L-43,7000 E Ave, Livermore, CA 94550 USA. EM mauche@cygnus.llnl.gov NR 32 TC 24 Z9 24 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 AUG 1 PY 1999 VL 520 IS 2 BP 822 EP 832 DI 10.1086/307498 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218EQ UT WOS:000081540600042 ER PT J AU Gibson, SE Biesecker, D Guhathakurta, M Hoeksema, JT Lazarus, AJ Linker, J Mikic, Z Pisanko, Y Riley, P Steinberg, J Strachan, L Szabo, A Thompson, BJ Zhao, XP AF Gibson, SE Biesecker, D Guhathakurta, M Hoeksema, JT Lazarus, AJ Linker, J Mikic, Z Pisanko, Y Riley, P Steinberg, J Strachan, L Szabo, A Thompson, BJ Zhao, XP TI The three-dimensional coronal magnetic field during Whole Sun Month SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; solar wind; Sun : corona; Sun : magnetic fields ID FARADAY-ROTATION MEASUREMENTS; SOLAR-WIND; SHEET CURRENTS; MODEL; MINIMUM; TEMPERATURE; EVOLUTION; STREAMER; PLASMA; VOLUME AB Combining models and observations, we study the three-dimensional coronal magnetic field during a period of extensive coordinated solar observations and analysis known as the Whole Sun Month (WSM) campaign (1996 August 10-September 8). The two main goals of the WSM campaign are addressed in this paper, namely, (1) to use the field configuration to link coronal features observed by coronagraphs and imaging telescopes to solar wind speed variations observed in situ and (2) to study the role of the three-dimensional coronal magnetic field in coronal force balance. Specifically, we consider how the magnetic field connects the two fastest wind streams to the two regions that have been the main foci of the WSM analysis: the equatorial extension of the north coronal hole (known as the Elephant's Trunk) and the axisymmetric streamer belt region on the opposite side of the Sun. We then quantitatively compare the different model predictions of coronal plasma and solar wind properties with observations and consider the implications for coronal force balance and solar wind acceleration. C1 Catholic Univ Amer, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Stanford Univ, Stanford, CA 94305 USA. MIT, Cambridge, MA 02139 USA. Inst Appl Geophys, Moscow, Russia. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Gibson, SE (reprint author), Univ Cambridge, Dept Appl Math & Theoret Phys, Silver St, Cambridge CB3 9EW, England. RI Gibson, Sarah/A-9189-2011; Thompson, Barbara/C-9429-2012 NR 63 TC 31 Z9 32 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1999 VL 520 IS 2 BP 871 EP 879 DI 10.1086/307496 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218EQ UT WOS:000081540600048 ER PT J AU Brotherton, MS van Breugel, W Stanford, SA Smith, RJ Boyle, BJ Miller, L Shanks, T Croom, SM Filippenko, AV AF Brotherton, MS van Breugel, W Stanford, SA Smith, RJ Boyle, BJ Miller, L Shanks, T Croom, SM Filippenko, AV TI A spectacular poststarburst quasar SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : interactions; galaxies : starburst; quasars : emission lines; quasars : general ID GALAXIES; EMISSION; QSOS; SKY AB We report the discovery of a spectacular "poststarburst quasar" UN J1025-0040 (B = 19; z = 0.634). The optical spectrum is a chimera, displaying the broad Mg II lambda 2800 emission line and strong blue continuum characteristic of quasars, but is dominated in the red by a large Balmer jump and prominent high-order Balmer absorption lines indicative of a substantial young stellar population at similar redshift. Stellar synthesis population models show that the stellar component is consistent with a 400 Myr old instantaneous starburst with a mass of less than or similar to 10(11) M.. A deep, K-s-band image taken in similar to 0." 5 seeing shows a point source surrounded by asymmetric extended fuzz, Approximately 70% of the light is unresolved, the majority of which is expected to be emitted by the starburst. While starbursts and galaxy interactions have been previously associated with quasars, no quasar ever before has been seen with such an extremely luminous young stellar population. C1 Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. Anglo Australian Observ, Epping, NSW 2121, Australia. Univ Oxford, Dept Phys, Oxford OX1 3RH, England. Univ Durham, Dept Phys, Durham DH1 3LE, England. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. RP Brotherton, MS (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, 7000 East Ave,POB 808,L-413, Livermore, CA 94550 USA. NR 31 TC 51 Z9 52 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1999 VL 520 IS 2 BP L87 EP L90 DI 10.1086/312152 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 218ER UT WOS:000081540700003 ER PT J AU Newberg, HJ Richards, GT Richmond, M Fan, XH AF Newberg, HJ Richards, GT Richmond, M Fan, XH TI Catalog of four-color photometry of stars, galaxies, and QSOs using SDSS filters SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE catalogs; galaxies : photometry; quasars : general; stars : fundamental parameters; techniques : photometric ID F-STARS; SYSTEM; POLE AB We present a catalog containing the measurements of 2262 sources, including 334 extended sources, 1915 point sources, and 13 known QSOs, in five SDSS passbands. Of these objects, over 1600 are measured in 15 fields covering 0.5 deg(2), with a limiting magnitude of r* < 19.5, similar to the photometric limit of the SDSS spectroscopic survey. Color plots of the data show that stars, galaxies, and quasars are fairly well separated by color alone. The stellar locus populates a ribbon-like subset of color-color-color space. It is shown that stars, galaxies, and QSOs tend toward the same fundamental plane in three-dimensional color space. The stars are compared with synthetic photometry from Kurucz models; the agreement is consistent with the errors in the data. The stellar locus moves in color space by about a tenth of a magnitude from r* = 14 to r* = 19.5. The shift is consistent with a shift in the metallicity from about [Me/H] = -1 to [Me/H] = -2. We compare this with previously measured metallicity gradients as a function of distance from the galactic plane. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. Princeton Univ, Princeton, NJ 08544 USA. RP Newberg, HJ (reprint author), Fermi Natl Accelerator Lab, Kirk Rd & Pine St, Batavia, IL 60510 USA. NR 18 TC 19 Z9 19 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD AUG PY 1999 VL 123 IS 2 BP 377 EP 435 DI 10.1086/313241 PG 59 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 236PA UT WOS:000082606700002 ER PT J AU Savin, DW Kahn, SM Linkemann, J Saghiri, AA Schmitt, M Grieser, M Repnow, R Schwalm, D Wolf, A Bartsch, T Brandau, C Hoffknecht, A Muller, A Schippers, S Chen, MH Badnell, NR AF Savin, DW Kahn, SM Linkemann, J Saghiri, AA Schmitt, M Grieser, M Repnow, R Schwalm, D Wolf, A Bartsch, T Brandau, C Hoffknecht, A Muller, A Schippers, S Chen, MH Badnell, NR TI Dielectronic recombination in photoionized gas. II. Laboratory measurements for Fe XVIII and Fe XIX SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE atomic data; atomic processes; galaxies : active; instabilities; X-rays : general ID ELECTRON-ION RECOMBINATION; HIGH-RESOLUTION MEASUREMENT; STORAGE-RING TSR; RATE COEFFICIENTS; LINE EMISSION; IONIZATION EQUILIBRIUM; ISOELECTRONIC SEQUENCE; FLUORINELIKE IONS; LOW ENERGIES; IRON AB In photoionized gases with cosmic abundances, dielectronic recombination (DR) proceeds primarily via nlj --> nl'j' core excitations (delta n = 0 DR). We have measured the resonance strengths and energies for Fe XVIII to Fe XVII and Fe XIX to Fe XVIII delta n = 0 DR. Using our measurements, we have calculated the Fe XVIII and Fe XIX An = 0 DR rate coefficients. Significant discrepancies exist between our inferred rates and those of published calculations. These calculations overestimate the DR rates by factors of similar to 2 or underestimate it by factors of similar to 2 to orders of magnitude, but none are in good agreement with our results. Almost all published DR rates for modeling cosmic plasmas are computed using the same theoretical techniques as the above-mentioned calculations. Hence, our measurements call into question all theoretical delta n = 0 DR rates used for ionization balance calculations of cosmic plasmas. At temperatures where the Fe XVIII and Fe XIX fractional abundances are predicted to peak in photoionized gases of cosmic abundances, the theoretical rates underestimate the Fe XVIII DR rate by a factor of similar to 2 and overestimate the Fe rat DR rate by a factor of similar to 1.6. We have carried out new multiconfiguration DiracFock and multiconfiguration Breit-Pauli calculations which agree with our measured resonance strengths and rate coefficients to within typically better than less than or similar to 30%. We provide a fit to our inferred rate coefficients for use in plasma modeling. Using our DR measurements, we infer a factor of similar to 2 error in the Fe XX through Fe XXIV delta n = 0 DR rates. We investigate the effects of this estimated error for the well-known thermal instability of photoionized gas. We find that errors in these rates cannot remove the instability, but they do dramatically affect the range in parameter space over which it forms. C1 Columbia Univ, Dept Phys, New York, NY 10027 USA. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. Univ Heidelberg, Inst Phys, D-69120 Heidelberg, Germany. Univ Giessen, Strahlenzentrum, Inst Kernphys, D-35392 Giessen, Germany. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Strathclyde, Dept Phys & Appl Phys, Glasgow G4 0NG, Lanark, Scotland. RP Savin, DW (reprint author), Columbia Univ, Dept Phys, 538 W 120th St, New York, NY 10027 USA. RI Schippers, Stefan/A-7786-2008; Muller, Alfred/A-3548-2009; Savin, Daniel/B-9576-2012 OI Schippers, Stefan/0000-0002-6166-7138; Muller, Alfred/0000-0002-0030-6929; Savin, Daniel/0000-0002-1111-6610 NR 51 TC 70 Z9 70 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD AUG PY 1999 VL 123 IS 2 BP 687 EP 702 DI 10.1086/313247 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 236PA UT WOS:000082606700011 ER PT J AU Grant, KE Chuang, CC Grossman, AS Penner, JE AF Grant, KE Chuang, CC Grossman, AS Penner, JE TI Modeling the spectral optical properties of ammonium sulfate and biomass burning aerosols: parameterization of relative humidity effects and model results SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT 6th International Conference on Carbonaceous Particles in the Atmosphere CY SEP 22-24, 1997 CL VIENNA, AUSTRIA DE aerosol carbonaceous; hygroscopic aerosols; aerosol radiative properties; radiative transfer; radiative forcing ID ANTHROPOGENIC SULFATE; CLIMATE; DISTRIBUTIONS AB The importance of including the global and regional radiative effects of aerosols in climate models has increasingly been realized. Accurate modeling of solar radiative forcing due to aerosols from anthropogenic sulfate and biomass burning emissions requires adequate spectral resolution and treatment of spatial and temporal variability. The variation of aerosol spectral optical properties with local relative humidity and dry aerosol composition must be considered. Because the cost of directly including Mie calculations within a climate model is prohibitive, parameterizations from off-line calculations must be used. Starting from a log-normal size distribution of dry ammonium sulfate, we developed optical properties for tropospheric sulfate aerosol at 15 relative humidities up to 99%. The resulting aerosol size distributions were then used to calculate bulk optical properties at wavelengths between 0.175 and 4 mu m. Finally, functional fits of optical properties were made for each of 12 wavelength bands as a function of relative humidity. Significant variations in optical properties occurred across the total solar spectrum. Relative increases in specific extinction and asymmetry factor with increasing relative humidity became larger at longer wavelengths. Significant variation in single-scattering albedo was found only in the longest near-IR band. This is also the band with the lowest single scattering albedo. A similar treatment was done for aerosols from biomass burning. In this case, two size distributions were considered. One was based on a distribution measured for Northern Hemisphere temperate forest fires while the second was based on a measured size distribution for tropical fires. Equilibrium size distributions and compositions were calculated for 15 relative humidities and five black carbon fractions. Mie calculations and band averages of optical properties were done for each of the resulting 75 cases. Finally, fits were made for each of 12 spectral bands as functions of relative humidity and black carbon fraction. These optical properties result in global average forcing from anthropogenic sulfate aerosols of - 0.81 Wm(-2). The global average forcing for biomass aerosols ranged from - 0.23 to - 0.16 Wm-2 depending on the assumed size distribution, while fossil fuel organic and black carbon are estimated to heat the atmosphere by about 0.16 Wm(-2). Published by Elsevier Science Ltd. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Michigan, Dept Atmospher Ocean & Space Studies, Ann Arbor, MI 48109 USA. RP Grant, KE (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Penner, Joyce/J-1719-2012; chuang, cathy/H-4814-2012 NR 29 TC 49 Z9 52 U1 3 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD AUG PY 1999 VL 33 IS 17 BP 2603 EP 2620 DI 10.1016/S1352-2310(99)00077-1 PG 18 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 208DU UT WOS:000080975600002 ER PT J AU Corrigan, CE Novakov, T AF Corrigan, CE Novakov, T TI Cloud condensation nucleus activity of organic compounds: a laboratory study SO ATMOSPHERIC ENVIRONMENT LA English DT Article; Proceedings Paper CT 6th International Conference on Carbonaceous Particles in the Atmosphere CY SEP 22-24, 1997 CL VIENNA, AUSTRIA DE organic aerosols; cloud condensation nuclei ID ANTHROPOGENIC SULFATE AEROSOLS; ATMOSPHERIC PARTICLES; SIZE DISTRIBUTIONS; SMOKE PARTICLES; NUCLEATION; DERIVATION; BEHAVIOR; CARBON AB Critical or activation diameters of laboratory generated organic aerosols composed of succinic acid, adipic acid and glucose were determined. Measurements of sodium chloride and ammonium sulfate aerosols were performed for comparison. Our experimental approach involved producing single component aerosol particles of a known size, and measuring the fraction of aerosol number concentrations (CN) that act as CCN at several supersaturations. The particle diameter (D-50) at which the CCN/CN ratio of 0.50 is reached is defined as the critical, or activation, diameter. These experimentally derived diameters are compared with the theoretical critical diameter(D-C). The results indicate that highly water-soluble organic compounds exhibit critical diameters that approach that of ammonium sulfate. Published by Elsevier Science Ltd. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Corrigan, CE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, MS-73, Berkeley, CA 94720 USA. NR 31 TC 118 Z9 121 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD AUG PY 1999 VL 33 IS 17 BP 2661 EP 2668 DI 10.1016/S1352-2310(98)00310-0 PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 208DU UT WOS:000080975600006 ER PT J AU Berry, EA Zhang, Z Huang, LS Kim, SH AF Berry, EA Zhang, Z Huang, LS Kim, SH TI Structures of quinone-binding sites in be complexes: functional implications SO BIOCHEMICAL SOCIETY TRANSACTIONS LA English DT Article; Proceedings Paper CT Colloquium on Quinone-Binding Sites in Membrane Proteins - Structure, Function and Applied Aspects CY APR 07-09, 1999 CL UNIV GLASGOW, GLASGOW, SCOTLAND SP AgrEvo UK Ltd, BASF HO UNIV GLASGOW ID CYTOCHROME BC(1) COMPLEX; IRON-SULFUR PROTEIN; INHIBITOR BINDING; RESPIRATORY-CHAIN; C REDUCTASE; BC1 COMPLEX; OXIDATION; MECHANISM; OXIDOREDUCTASE; TITRATION C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Grad Grp Biophys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Berry, EA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 25 TC 15 Z9 17 U1 0 U2 2 PU PORTLAND PRESS PI LONDON PA 59 PORTLAND PLACE, LONDON W1N 3AJ, ENGLAND SN 0300-5127 J9 BIOCHEM SOC T JI Biochem. Soc. Trans. PD AUG PY 1999 VL 27 IS 4 BP 565 EP 572 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 230RF UT WOS:000082263600042 PM 10917643 ER PT J AU Ashbaugh, HS Garde, S Hummer, G Kaler, EW Paulaitis, ME AF Ashbaugh, HS Garde, S Hummer, G Kaler, EW Paulaitis, ME TI Conformational equilibria of alkanes in aqueous solution: Relationship to water structure near hydrophobic solutes SO BIOPHYSICAL JOURNAL LA English DT Article ID STATISTICAL MECHANICAL FORMULATION; MONTE-CARLO SIMULATION; MEAN-FORCE EXPANSION; CAVITY SURFACE-AREA; FREE-ENERGY; MOLECULAR-DYNAMICS; COMPUTER-SIMULATION; BIOLOGICAL MACROMOLECULES; CONFINED FLUID; NORMAL-BUTANE AB Conformational free energies of butane, pentane, and hexane in water are calculated from molecular simulations with explicit waters and from a simple molecular theory in which the local hydration structure is estimated based on a proximity approximation. This proximity approximation uses only the two nearest carbon atoms on the alkane to predict the local water density at a given point in space. Conformational free energies of hydration are subsequently calculated using a free energy perturbation method. Quantitative agreement is found between the free energies obtained from simulations and theory. Moreover, free energy calculations using this proximity approximation are approximately four orders of magnitude faster than those based on explicit water simulations. Our results demonstrate the accuracy and utility of the proximity approximation for predicting water structure as the basis for a quantitative description of n-alkane conformational equilibria in water. In addition, the proximity approximation provides a molecular foundation for extending predictions of water structure and hydration thermodynamic properties of simple hydrophobic solutes to larger clusters or assemblies of hydrophobic solutes. C1 Johns Hopkins Univ, Dept Chem Engn, Baltimore, MD 21218 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Delaware, Dept Chem Engn, Newark, DE 19716 USA. Univ Delaware, Ctr Mol & Engn Thermodynam, Newark, DE 19716 USA. RP Paulaitis, ME (reprint author), Johns Hopkins Univ, Dept Chem Engn, Maryland Hall 221,3400 N Charles St, Baltimore, MD 21218 USA. RI Garde, Shekhar/C-3060-2008; Ashbaugh, Henry/C-9767-2011; Hummer, Gerhard/A-2546-2013 OI Hummer, Gerhard/0000-0001-7768-746X NR 77 TC 36 Z9 36 U1 3 U2 13 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD AUG PY 1999 VL 77 IS 2 BP 645 EP 654 PG 10 WC Biophysics SC Biophysics GA 224VK UT WOS:000081920500001 PM 10423414 ER PT J AU Gallas, JM Littrell, KC Seifert, S Zajac, GW Thiyagarajan, P AF Gallas, JM Littrell, KC Seifert, S Zajac, GW Thiyagarajan, P TI Solution structure of copper ion-induced molecular aggregates of tyrosine melanin SO BIOPHYSICAL JOURNAL LA English DT Article ID SYNTHETIC MELANIN; SCATTERING AB Melanin, the ubiquitous biological pigment, provides photoprotection by efficient filtration of light and also by its antioxidant behavior. In solutions of synthetic melanin, both optical and antioxidant behavior are affected by the aggregation states of melanin. We have utilized small-angle x-ray and neutron scattering to determine the molecular dimensions of synthetic tyrosine melanin in its unaggregated state in D2O and H2O to study the structure of melanin aggregates formed in the presence of copper ions at various copper-to-melanin molar ratios. In the absence of copper ions, or at low copper ion concentrations, tyrosine melanin is present in solution as a sheet-like particle with a mean thickness of 12.5 Angstrom and a lateral extent of similar to 54 Angstrom. At a copper-to-melanin molar ratio of 0.6, melanin aggregates to form long, rod-like structures with a radius of 32 Angstrom. At a higher copper ion concentration, with a copper-to-melanin ratio of 1.0, these rod-like structures further aggregate, forming sheet-like structures with a mean thickness of 51 Angstrom. A change in the charge of the ionizable groups induced by the addition of copper ions is proposed to account for part of the aggregation. The data also support a model for the copper-induced aggregation of melanin driven by rr stacking assisted by peripheral Cu2+ complexation. The relationship between our results and a previous hypothesis for reduced cellular damage from bound-to-melanin redox metal ions is also discussed. C1 Univ Texas, Div Phys & Earth Sci, San Antonio, TX 78249 USA. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Amoco Res Ctr, Naperville, IL 60566 USA. RP Gallas, JM (reprint author), Univ Texas, Div Phys & Earth Sci, 6900 N Loop 1604 W, San Antonio, TX 78249 USA. RI Littrell, Kenneth/D-2106-2013 OI Littrell, Kenneth/0000-0003-2308-8618 NR 20 TC 64 Z9 65 U1 2 U2 12 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD AUG PY 1999 VL 77 IS 2 BP 1135 EP 1142 PG 8 WC Biophysics SC Biophysics GA 224VK UT WOS:000081920500045 PM 10423458 ER PT J AU Finch, RJ Cooper, MA Hawthorne, FC Ewing, RC AF Finch, RJ Cooper, MA Hawthorne, FC Ewing, RC TI Refinement of the crystal structure of rutherfordine SO CANADIAN MINERALOGIST LA English DT Article DE rutherfordine; crystal structure; uranyl carbonate; uranium mineral ID SPENT NUCLEAR-FUEL; OXIDIZING CONDITIONS; URANIUM; CORROSION; MINERALS; PHASES; 90-DEGREES-C; DISSOLUTION; MECHANISMS; SPECIATION AB Rutherfordine, UO2CO3, is orthorhombic, a 4.840(1), b 9.273(2), c 4.298(1) Angstrom, V 192.90(7) Angstrom(3), space group Imm2, Z = 2. The structure was refined to an R index of 2.2% on the basis of 306 unique data [\F-o\/sigma(\F-o\) > 5] measured with MoK alpha X-radiation on a single-crystal diffractometer. The structure consists of neutral sheets of edge- and corner-sharing (UO8) hexagonal bipyramids and (CO3) triangles, as originally proposed by Christ et al. (1955); our refinement, however, shows that (CO3) groups in alternate layers have the same orientation, not opposite orientations as originally reported. The refined value of the U-O(uranyl) distance is strongly affected by the details of the absorption correction, ranging from 1.71 to 1.80 a as a function of the plate-glancing angle used in an empirical psi-scan absorption correction and as a function of the type of weighting scheme used in the refinement. The Gaussian-quadrature method of integration also shows similar problems, but they are less extreme. The preferred value for the U-O(uranyl) distance in rutherfordine is similar to 1.745 Angstrom; as rutherfordine contains no H atoms, the O(uranyl) atom is [1]coordinated, and should have the shortest U-O(uranyl) distance stereochemically possible. The current work suggests that U-O(uranyl) values less than 1.745 Angstrom reported in other studies are adversely affected by less-than-optimum absorption corrections. C1 Univ Manitoba, Dept Geol Sci, Winnipeg, MB R3T 2N2, Canada. Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. RP Finch, RJ (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Hawthorne, Frank/F-6864-2011; Finch, Robert/D-9553-2013 OI Hawthorne, Frank/0000-0001-6405-9931; Finch, Robert/0000-0001-9342-5574 NR 40 TC 43 Z9 43 U1 1 U2 8 PU MINERALOGICAL ASSOC CANADA PI NEPEAN PA CITYVIEW 78087, NEPEAN, ONTARIO K2G 5W2, CANADA SN 0008-4476 J9 CAN MINERAL JI Can. Mineral. PD AUG PY 1999 VL 37 BP 929 EP 938 PN 4 PG 10 WC Mineralogy SC Mineralogy GA 253CQ UT WOS:000083539400007 ER PT J AU Araki, R Fukumura, R Fujimori, A Taya, Y Shiloh, Y Kurimasa, A Burma, S Li, GC Chen, DJ Sato, K Hoki, Y Tatsumi, K Abe, M AF Araki, R Fukumura, R Fujimori, A Taya, Y Shiloh, Y Kurimasa, A Burma, S Li, GC Chen, DJ Sato, K Hoki, Y Tatsumi, K Abe, M TI Enhanced phosphorylation of p53 serine 18 following DNA damage in DNA-dependent protein kinase catalytic subunit-deficient cells SO CANCER RESEARCH LA English DT Article ID V(D)J RECOMBINATION; IONIZING-RADIATION; MOUSE; MUTATION; MICE; RADIOSENSITIVITY; MUTANTS; PKCS; GENE AB DNA-dependent protein kinase (DNA-PK) controls signal transduction following DNA damage. However, the molecular mechanism of the signal transduction has been elusive. A number of candidates for substrates of DNA-PK have been reported on the basis of the in vitro assay system. In particular, the Ser-15 amino acid residue in p53 was one of the first such in vitro substrates to be described, and it has drawn considerable attention due to its biological significance. Moreover, p53 Ser-15 is a site that has been shown to be phosphorylated in response to DNA damage. In addition, crucial evidence indicating that DNA-PK controls the transactivation of p53 following DNA damage was reported quite recently. To clarify these important issues, we conducted the experiments with dna-pkcs null mutant cells, including gene knockout cells. As a result, we detected enhanced phosphorylation of p53 Ser-18, which corresponds to Ser-15 of human p53, and significant expression of p21 and mdm2 following ionizing radiation. Furthermore, we identified a missense point mutation in the p53 DNA-binding motif region in SCGR11 cells, which were established from severe combined immunodeficient (SCID) mice and used for previous study on the role of DNA-PK in p53 transactivation. Our observation clearly indicates that DNA-PK catalytic subunit does not phosphorylate p53 Ser-18 in vivo or control the transactivation of p53 in response to DNA damage, and these results further emphasize the different pathways in which ataxia telangiectasia-mutated (ATM);and DNA-PK operate following radiation damage. C1 Natl Inst Radiol Sci, Dept Biol & Oncol, Inage Ku, Chiba 2638555, Japan. Chiba Univ, Chiba 263, Japan. Natl Canc Ctr, Res Inst, Tokyo 104, Japan. Tel Aviv Univ, Sackler Sch Med, IL-69978 Ramat Aviv, Israel. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Mem Sloan Kettering Canc Ctr, New York, NY 10021 USA. Kinki Univ, Wakayama 64964, Japan. RP Abe, M (reprint author), Natl Inst Radiol Sci, Dept Biol & Oncol, Inage Ku, Anagawa 4-9-1, Chiba 2638555, Japan. NR 21 TC 41 Z9 42 U1 0 U2 1 PU AMER ASSOC CANCER RESEARCH PI BIRMINGHAM PA PO BOX 11806, BIRMINGHAM, AL 35202 USA SN 0008-5472 J9 CANCER RES JI Cancer Res. PD AUG 1 PY 1999 VL 59 IS 15 BP 3543 EP 3546 PG 4 WC Oncology SC Oncology GA 224GT UT WOS:000081890200003 PM 10446957 ER PT J AU Anderson, LE Boorman, GA Morris, JE Sasser, LB Mann, PC Grumbein, SL Hailey, JR McNally, A Sills, RC Haseman, JK AF Anderson, LE Boorman, GA Morris, JE Sasser, LB Mann, PC Grumbein, SL Hailey, JR McNally, A Sills, RC Haseman, JK TI Effect of 13 week magnetic field exposures on DMBA-initiated mammary gland carcinomas in female Sprague-Dawley rats SO CARCINOGENESIS LA English DT Article ID MALE BREAST-CANCER; ELECTROMAGNETIC-FIELDS; CARCINOGENICITY; 50-HZ; RISK; MORTALITY; WORKERS; WOMEN AB Several studies suggest that exposure to 50 Hz magnetic fields may promote chemically induced breast cancer in rats. Groups of 100 female Sprague-Dawley rats were initiated with four weekly 5 mg gavage doses of 7,12-dimethylbenz[a]anthracene (DMBA) starting at 50 days of age. After the first weekly DMBA administration, exposure to ambient fields (sham exposed), 50 Hz magnetic fields at either 1 or 5 G field intensity or 60 Hz fields at 1 G for 18.5 h/day, 7 days/week was initiated. Exposure continued for 13 weeks. A vehicle control group without DMBA was included. In a second study, using lower doses of DMBA, groups of 100 female Sprague-Dawley rats were initiated with four weekly doses of 2 mg of DMBA starting at 50 days of age followed, after the first weekly DMBA administration, by exposure to ambient fields (sham exposed) or 50 Hz magnetic fields at either 1 or 5 G field intensity for 18.5 h/day, 7 days/week for 13 weeks. Rats were weighed and palpated meekly for the presence of tumors. There was no effect of magnetic field exposure on body weight gains or on the time of appearance of mammary tumors in either study. At the end of 13 weeks, the animals were killed and the mammary tumors counted and measured, Mammary gland masses found grossly were examined histologically. In the first 13 week study, the mammary gland carcinoma incidences were 92, 86, 96 and 96% for the DMBA controls, 1 G, 50 Hz, 5 G, 50 Hz and 1 G, 60 Hz groups, respectively. The total numbers of carcinomas were 691, 528 (P < 0.05, decrease), 561 and 692 for the DMBA controls, 1 G, 50 Hz, 5 G, 50 Hz and 1 G, 60 Hz groups, respectively. In study 2, the mammary gland carcinoma incidences mere 43, 48 and 38% for the DMBA controls, 1 G, 50 Hz and 5 G, 50 Hz groups, respectively. The total numbers of carcinomas were 102, 90 and 79 for the DMBA controls, 1 G, 50 Hz and 5 G, 50 Hz groups, respectively. There was no effect of magnetic field exposure on tumor size either by in-life palpation or by measurement at necropsy in either study. There was no evidence that 50 or 60 Hz magnetic fields promoted breast cancer in these studies in female rats. These studies do not support the hypothesis that magnetic field exposure promotes breast cancer in this DMBA rat model. C1 Pacific NW Lab, Richland, WA 99352 USA. NIEHS, Res Triangle Pk, NC 27709 USA. Expt Pathol Lab Inc, Res Triangle Pk, NC 27709 USA. RP Boorman, GA (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 28 TC 27 Z9 29 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0143-3334 J9 CARCINOGENESIS JI Carcinogenesis PD AUG PY 1999 VL 20 IS 8 BP 1615 EP 1620 DI 10.1093/carcin/20.8.1615 PG 6 WC Oncology SC Oncology GA 226DB UT WOS:000082004100034 PM 10426815 ER PT J AU Hartmann, T Paviet-Hartmann, P Rubin, JB Sickafus, KE AF Hartmann, T Paviet-Hartmann, P Rubin, JB Sickafus, KE TI Supercritical CO2 carbonation of cemented radioactive waste-forms - Influence on leachability and structure SO CEMENT AND CONCRETE RESEARCH LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Hartmann, T (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, MST-8,MS K762, Los Alamos, NM 87545 USA. NR 5 TC 4 Z9 4 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD AUG PY 1999 VL 29 IS 8 BP 1359 EP 1359 DI 10.1016/S0008-8846(99)00057-5 PG 1 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 238XD UT WOS:000082739300027 ER PT J AU Dahan, M Deniz, AA Ha, TJ Chemla, DS Schultz, PG Weiss, S AF Dahan, M Deniz, AA Ha, TJ Chemla, DS Schultz, PG Weiss, S TI Ratiometric measurement and identification of single diffusing molecules SO CHEMICAL PHYSICS LA English DT Article ID FLUORESCENCE CORRELATION SPECTROSCOPY; RESONANCE ENERGY-TRANSFER; CROSS-CORRELATION SPECTROSCOPY; ROOM-TEMPERATURE; CONFORMATIONAL FLUCTUATIONS; AQUEOUS-SOLUTION; DNA; DYNAMICS; EXCITATION; MICROSCOPY AB The concept of ratiometric identification and separation of sub-populations of single biomolecules which are labeled with individual fluorophores and are freely diffusing (or flowing) through the laser excitation volume is introduced. The efficacy of the scheme versus the signal and noise level is considered and a general theoretical framework and data analysis schemes are introduced. Experimental results that demonstrate distributions of single molecule fluorescence polarization anisotropy (smFPA) and single pair fluorescence resonance energy transfer (spFRET) in solution are presented. Ultimate resolution for identifying molecular observables such as conformational states, degree of freedom of motion and spectral distribution are discussed. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Howard Hughes Med Inst, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Weiss, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Ha, Taekjip/B-9506-2009; Dahan, Maxime /F-1740-2010; weiss, shimon/B-4164-2009 OI Ha, Taekjip/0000-0003-2195-6258; weiss, shimon/0000-0002-0720-5426 NR 56 TC 111 Z9 111 U1 0 U2 22 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD AUG 1 PY 1999 VL 247 IS 1 BP 85 EP 106 DI 10.1016/S0301-0104(99)00132-9 PG 22 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 231HT UT WOS:000082303000010 ER PT J AU Ha, TJ Ting, AY Liang, J Deniz, AA Chemla, DS Schultz, PG Weiss, S AF Ha, TJ Ting, AY Liang, J Deniz, AA Chemla, DS Schultz, PG Weiss, S TI Temporal fluctuations of fluorescence resonance energy transfer between two dyes conjugated to a single protein SO CHEMICAL PHYSICS LA English DT Article ID QUANTUM JUMPS; ROOM-TEMPERATURE; MOLECULES; POLARIZATION; SPECTROSCOPY; DYNAMICS; BLINKING AB Biological molecules together with available labeling chemistries provide an ideal setting to investigate the interaction between two closely spaced dye molecules. The photo-excitation of a donor molecule can be non-radiatively transferred to a near-by acceptor molecule via the induced-dipole-induced-dipole interaction in a distance-dependent manner. In this work, we further elaborate on single-molecule fluorescence resonance energy transfer measurements between two dye molecules attached to a single protein - staphylococcal nuclease molecules [T. Ha, A.Y. Ting, J. Liang, W.B. Caldwell, A.A. Deniz, D.S. Chemla, P.G. Schultz, S. Weiss, Proc. Natl. Acad. Sci. USA 96 (1999) 893-898]. Temporal fluctuations in the energy transfer signal include: (1) reversible transitions to dark states; (2) irreversible photodestruction; (3) intersystem crossing to and from the triplet state; (4) spectral fluctuations; (5) rotational dynamics of the dyes; and (6) distance changes between the two dyes. To extract biologically relevant information from such measurements, an experimental strategy and data analysis schemes are developed. First, abrupt photophysical events, such as (1)-(3) are identified and removed from the data. The remaining slow, gradual fluctuations in the energy transfer signal are due to spectral shifts, rotational dynamics and distance changes of the dyes. Direct measurements of each dye's spectral fluctuation and rotational dynamics indicate that these, by themselves, cannot fully account for the observed energy transfer fluctuations. It is therefore concluded that inter-dye distance changes must be present as well. The distance and orientational dynamics are shown to be dependent on the binding of the active-site inhibitor (deoxythymidine diphosphate) to the protein. The inhibitor most probably affects the protein's stability and the dye-protein interaction, possibly by amplifying the motion of the linker arm between the fluorophore and the protein. (C) 1999 Elsevier Science B.V, All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Howard Hughes Med Inst, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Weiss, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Ha, Taekjip/B-9506-2009; weiss, shimon/B-4164-2009 OI Ha, Taekjip/0000-0003-2195-6258; weiss, shimon/0000-0002-0720-5426 NR 26 TC 76 Z9 79 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD AUG 1 PY 1999 VL 247 IS 1 BP 107 EP 118 DI 10.1016/S0301-0104(99)00149-4 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 231HT UT WOS:000082303000011 ER PT J AU Weston, RE AF Weston, RE TI Anomalous or mass-independent isotope effects SO CHEMICAL REVIEWS LA English DT Review ID ISOTOPICALLY HEAVY OZONE; DIATOM DIATOM REACTIONS; CARBON-DIOXIDE; SYMMETRY RESTRICTIONS; THEORETICAL-ANALYSIS; TROPOSPHERIC OZONE; STRATOSPHERIC CO2; MOLECULAR-OXYGEN; NITROUS-OXIDE; MULTI-ISOTOPE C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Weston, RE (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 93 TC 75 Z9 76 U1 1 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2665 J9 CHEM REV JI Chem. Rev. PD AUG PY 1999 VL 99 IS 8 BP 2115 EP 2136 DI 10.1021/cr9800154 PG 22 WC Chemistry, Multidisciplinary SC Chemistry GA 227YP UT WOS:000082107800004 ER PT J AU Johal, MS Cao, YW Chai, XD Smilowitz, LB Robinson, JM Li, TJ McBranch, D Li, DQ AF Johal, MS Cao, YW Chai, XD Smilowitz, LB Robinson, JM Li, TJ McBranch, D Li, DQ TI Spontaneously self-assembled polar asymmetric multilayers formed by complementary H-bonds SO CHEMISTRY OF MATERIALS LA English DT Article ID SUM-FREQUENCY SPECTROSCOPY; BARBITURIC-ACID; INTERFACE; MONOLAYER; GENERATION; SURFACE AB Driven by weak intermolecular interactions between the complementary H-bonds, melamine derivatives and barbituric acids spontaneously self-assemble into the supramolecular ribbon shown. Surprisingly, the supramolecular ribbons stack into a polar, asymmetric (head-to-tail) multilayer structure during film formation. The structure-property relationship of these thick films was investigated using X-ray diffraction and several optical techniques. Spontaneously Self-Assembled Polar Asymmetric Multilayers Formed by Complementary H-Bonds [GRAPHICS] C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Jilin Univ, Dept Chem, Changchun 130023, Peoples R China. RP Li, DQ (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. NR 27 TC 23 Z9 24 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD AUG PY 1999 VL 11 IS 8 BP 1962 EP + DI 10.1021/cm990158m PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 227YZ UT WOS:000082108800005 ER PT J AU Fryxell, GE Liu, J Hauser, TA Nie, ZM Ferris, KF Mattigod, S Gong, ML Hallen, RT AF Fryxell, GE Liu, J Hauser, TA Nie, ZM Ferris, KF Mattigod, S Gong, ML Hallen, RT TI Design and synthesis of selective mesoporous anion traps SO CHEMISTRY OF MATERIALS LA English DT Article ID MOLECULAR-SIEVES; FUNCTIONALIZED MONOLAYERS; SILICA; TEMPLATES; MCM-41; FILMS AB Arsenic contamination of groundwater has recently commanded widespread public attention. Under many conditions, arsenic, and certain other environmentally relevant toxic metals such as chromium, exist in nature as oxyanions. Selective binding of anions is one of the most challenging problems in chemistry, biology, and materials and environmental science. In this paper we report the synthesis and use of metal-chelated ligands immobilized on mesoporous silica as novel anion binding materials. Nearly complete removal of arsenate and chromate has been achieved in the presence of competing anions for solutions containing more than 100 mg/L (ppm) toxic metal anions under a variety of conditions. Anion loading of more than 120 mg (anion)/g of adsorption materials is observed. A binding mechanism is also proposed on the basis of computer modeling. First, Cu(II) ions are bonded to ethylenediamine (EDA) Ligands to form octahedral complexes on the surface of the mesoporous silica. This gives rise to positively charged hosts with 3-fold symmetry that match the geometry of tetrahedral anions. The anion binding involves initial electrosteric coordination, followed by displacement of one ligand and direct binding with the Cu(II) center. C1 Pacific NW Lab, Richland, WA 99353 USA. RP Liu, J (reprint author), Pacific NW Lab, Richland, WA 99353 USA. NR 41 TC 197 Z9 201 U1 4 U2 42 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD AUG PY 1999 VL 11 IS 8 BP 2148 EP 2154 DI 10.1021/cm990104c PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 227YZ UT WOS:000082108800031 ER PT J AU Williams, DJ Kruger, JS McLeroy, AF Wilkinson, AP Hanson, JC AF Williams, DJ Kruger, JS McLeroy, AF Wilkinson, AP Hanson, JC TI Iridium(III) amine complexes as high-stability structure-directing agents for the synthesis of metal phosphates SO CHEMISTRY OF MATERIALS LA English DT Article ID ONE-DIMENSIONAL ALUMINOPHOSPHATE; CRYSTAL-STRUCTURE; ALUMINUM PHOSPHATE; HYDROTHERMAL SYNTHESIS; CHIRAL LAYERS; PLATE DATA; ZEOLITE; DIFFRACTION; CHAIN; MICROCRYSTAL AB The metal complexes Ir(en)(3)(3+) and M((+/-)chxn)(3)(3+) (en = 1,2-diaminoethane, chxn = trans-1,2-diaminocyclohexane, M = Kr or Co) have been used to synthesize the layered compound Delta,Lambda-Ir(en)(3)[Al(3)P(4)O(16)]. xH(2)O (x approximate to 3.45) and the chain compounds M(chxn)(3)[Al(2)P(3)O(12)]. xH(2)O (x approximate to 4). The chain compounds contain two of the eight possible isomeric forms of the cation, Lambda(lel(2)ob)-[M(S,S-chxn)(2)(R,R-chxn)](3+) and its mirror image Delta(lel(2)ob)-[M(R,R-chxn)(2)(S,S-chxn)](3+). Microcrystals of the Ir(en)(3)(3+) and Ir(chxn)(3)(3+) containing AlPOs were structurally characterized using synchrotron radiation. Delta,Lambda-Ir(en)(3)[Al(3)P(4)O(16)]. xH(2)O is isomorphous with the previously reported material Delta,Lambda-Co(en)(3)[Al(3)P(4)O(16)]. xH(2)O. The materials prepared using Co((+/-)chxn)(3)(3+) and Ir((+/-)chxn)(3)(3+) are also isostructural with one another and contain a new type of aluminophosphate chain. The use of Ir(III) in the structure-directing metal complex enabled the use of much harsher hydrothermal conditions for the metal phosphate synthesis than could be employed with the corresponding Co(III) complexes. Ir(C(2)N(2)H(8))(3)[Al(3)P(4)O(16)]. 3.45H(2)O: M(r) = 895.5, orthorhombic, Pnna, a = 8.548(5), b = 21.983(14), c = 13.970(9) Angstrom, V = 2625(3) Angstrom(3), Z = 4, rho(calc) = 2.266 g cm(-3), lambda = 1.1167 Angstrom, mu = 14.03 mm(-1), F(000) = 1762, T = 293 K, R(F) = 0.128 for 954 reflections I > 2 sigma(I). Ir(C(6)N(2)H(14))(3)Al(2)P(3)O(12). 4H(2)O: M(r) = 945.7, triclinic, P (1) over bar, a = 9.649(5), b = 12.365(9), c = 16.083(8) Angstrom, alpha = 100.02(6), beta = 101.64(5), gamma = 104.75(6)degrees, V = 1765(2) Angstrom(3), Z = 2, rho(calc) = 1.779 g cm(-3), lambda = 1.1167 Angstrom, mu = 9.747 mm(-1), F(000) = 952, T = 293 K, R(F) = 0.128 for 966 reflections I > 2 sigma(I). C1 Georgia Inst Technol, Sch Chem & Biochem, Atlanta, GA 30332 USA. Kennesaw State Univ, Dept Chem, Marietta, GA 30061 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Wilkinson, AP (reprint author), Georgia Inst Technol, Sch Chem & Biochem, Atlanta, GA 30332 USA. RI Wilkinson, Angus/C-3408-2008; Hanson, jonathan/E-3517-2010 OI Wilkinson, Angus/0000-0003-2904-400X; NR 68 TC 47 Z9 47 U1 2 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD AUG PY 1999 VL 11 IS 8 BP 2241 EP 2249 DI 10.1021/cm9901921 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 227YZ UT WOS:000082108800044 ER PT J AU Thompson, HA Parks, GA Brown, GE AF Thompson, HA Parks, GA Brown, GE TI Ambient-temperature synthesis, evolution, and characterization of cobalt-aluminum hydrotalcite-like solids SO CLAYS AND CLAY MINERALS LA English DT Article DE anionic clay; cation ordering; coprecipitation; EXAFS; hydrotalcite; IGP-MS; solubility product; TEM; metal contamination; solid solution; interstratification ID LAYERED DOUBLE HYDROXIDES; SURFACE PRECIPITATION; AQUEOUS-SOLUTION; ANION-EXCHANGE; SORPTION; CHEMISTRY; MINERALS; OXIDES; IONS; ADSORPTION AB Double hydroxide solids precipitated homogeneously from three laboratory-synthesized aqueous solutions that simulated mildly contaminated surface or groundwater. Over a limited pH range, precipitates formed rapidly from dissolved ions, and more slowly by incorporating ions dissolving from other solids, including highly soluble aluminous solids. The precipitates were characterized by size and shape via transmission electron microscopy (TEM), by composition via inductively coupled plasma-mass spectrometry (ICP-MS) of mother solutions and analytical electron microscopy (AEM) of precipitates, and by structure via powder X-ray diffraction (XRD), TEM, and extended X-ray absorption fine structure (EXAFS) spectroscopy. They were identified as nanocrystalline cobalt hydrotalcite (CoHT) of the form [Co(II)(1-x)Al(III)(x)(OH)(2)](x+)(A(x/n)(n-)). mH(2)O, with x = 0.17-0.25, A = CO32-, NO3-, or H3SiO4-, n = anion charge and m undetermined. Complete solid solution may exist at the macroscopic level for the range of stoichiometries reported, but clustering of Co atoms within hydroxide layers indicates a degree of immiscibility at the molecular scale. Composition evolved toward the Go-rich endmember with time for at least one precipitate. The small layer charge in the x = 0.17 precipitate caused anionic interlayers to be incomplete, producing interstratification of hydrotalcite and brucite-like layers. Solubility products estimated from solution measurements for the observed final CoHT stoichiometries suggest that CoHT is less soluble than the inactive forms of Co(OH)(2) and CoCO3 near neutral pH. Low solubility and rapid formation suggest that CoHT solids may be important sinks for Co in contact with near neutral pH waters. Because hydrotalcite can incorporate a range of transition metals, precipitation of hydrotalcite may be similarly effective for removing other trace metals from natural waters. C1 Stanford Univ, Dept Geog & Environm Sci, Stanford, CA 94305 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Thompson, HA (reprint author), Univ Calif Los Alamos Natl Lab, MS D469, Los Alamos, NM 87545 USA. NR 50 TC 47 Z9 48 U1 4 U2 15 PU CLAY MINERALS SOCIETY PI BOULDER PA PO BOX 4416, BOULDER, CO 80306 USA SN 0009-8604 J9 CLAY CLAY MINER JI Clay Clay Min. PD AUG PY 1999 VL 47 IS 4 BP 425 EP 438 DI 10.1346/CCMN.1999.0470405 PG 14 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy; Soil Science SC Chemistry; Geology; Mineralogy; Agriculture GA 231TM UT WOS:000082326300005 ER PT J AU Hudson, EA Terminello, LJ Viani, BE Denecke, M Reich, T Allen, PG Bucher, JJ Shuh, DK Edelstein, NM AF Hudson, EA Terminello, LJ Viani, BE Denecke, M Reich, T Allen, PG Bucher, JJ Shuh, DK Edelstein, NM TI The structure of U6+ sorption complexes on vermiculite and hydrobiotite SO CLAYS AND CLAY MINERALS LA English DT Article DE cation exchange; EXAFS; sorption; surface complex; uranium; uranyl; vermiculite; XANES; XRD ID NEAR-EDGE STRUCTURE; URANYL-ION; URANIUM STRUCTURES; EXAFS; MONTMORILLONITE; SPECIATION; SCATTERING; SILICATE; CLAY AB The sorption of the uranyl oxo-cation (UO22+)at different types of binding sites on layer silicate mineral surfaces was investigated. Well-characterized samples of vermiculite and hydrobiotite were exposed to aqueous uranyl under conditions designed to promote surface sorption either at fixed charge ion-exchange sites or at amphoteric surface hydroxyl sites. The local structure of uranium in the sorption samples was directly measured using uranium L-3-edge extended X-ray absorption fine structure (EXAFS). Polarized L-1- and L-3-edge X-ray absorption near-edge structure (XANES) measurements were used to characterize the orientation of uranyl groups in layered samples. X-ray diffraction (XRD) measurements of interlayer spacings were used to assess the effects of ion-exchange and dehydration upon the mineral structure. The most significant findings are: (1) Under conditions which greatly favor ion-exchange sorption mechanisms, uranyl retains a symmetric local structure suggestive of an outer-sphere complex, with a preferred orientation of the uranyl axis parallel to the mineral layers; (2) Upon dehydration, the ion-exchange complexes adopt a less symmetric structure, consistent with an inner-sphere complex, with less pronounced orientation of the uranyl axis; and (3) For conditions which favor sorption at surface hydroxyl sites, uranyl has a highly distorted equatorial shell, indicative of stronger equatorial ligation, and the detection of a neighboring U atom suggests the formation of surface precipitates and/or oligomeric complexes. C1 Lawrence Livermore Natl Lab, Glenn T Seaborg Inst Transactinium Sci, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, Earth & Environm Sci Directorate, Livermore, CA 94551 USA. Rossendorf Inc, Forschungszentrum Rossendorf EV, Inst Radiochem, D-01314 Dresden, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Hudson, EA (reprint author), Lam Res Corp, CA-3,4650 Cushing Pkwy, Fremont, CA 94538 USA. RI The Rossendorf Beamline at ESRF, ROBL/A-2586-2011; Reich, Tobias/C-7064-2016 OI Reich, Tobias/0000-0002-5600-3951 NR 29 TC 47 Z9 48 U1 1 U2 15 PU CLAY MINERALS SOC PI CHANTILLY PA 3635 CONCORDE PKWY, STE 500, CHANTILLY, VA 20151-1125 USA SN 0009-8604 EI 1552-8367 J9 CLAY CLAY MINER JI Clay Clay Min. PD AUG PY 1999 VL 47 IS 4 BP 439 EP 457 DI 10.1346/CCMN.1999.0470406 PG 19 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy; Soil Science SC Chemistry; Geology; Mineralogy; Agriculture GA 231TM UT WOS:000082326300006 ER PT J AU Rosenberg, NJ Epstein, DJ Wang, D Vail, L Srinivasan, R Arnold, JG AF Rosenberg, NJ Epstein, DJ Wang, D Vail, L Srinivasan, R Arnold, JG TI Possible impacts of global warming on the hydrology of the Ogallala aquifer region SO CLIMATIC CHANGE LA English DT Article ID ATMOSPHERIC CARBON-DIOXIDE; YIELD; CLIMATE; SENSITIVITY; SIMULATION; GROWTH; MODEL; CROPS; USA AB The Ogallala or High Plains aquifer provides water for about 20% of the irrigated land in the United States. About 20 km(3) (16.6 million acre-feet) of water are withdrawn annually from this aquifer. In general, recharge has not compensated for withdrawals since major irrigation development began in this region in the 1940s. The mining of the Ogallala has been pictured as an analogue to climate change in that many GCMs predict a warmer and drier future for this region. In this paper we attempt to anticipate the possible impacts of climate change on the sustainability of the aquifer as a source of water for irrigation and other purposes in the region. We have applied HUMUS, the Hydrologic Unit Model of the U.S. to the Missouri and Arkansas-White-Red water resource regions that overlie the Ogallala. We have imposed three general circulation model (GISS, UKTR and BMRC) projections of future climate change on this region and simulated the changes that may be induced in water yields (runoff plus lateral flow) and ground water recharge. Each GCM was applied to HUMUS at three levels of global mean temperature (GMT) to represent increasing severity of climate change (a surrogate for time). HUMUS was also run at three levels of atmospheric CO2 concentration (hereafter denoted by [CO2]) in order to estimate the impacts of direct CO2 effects on photosynthesis and evapotranspiration. Since the UKTR and GISS GCMs project increased precipitation in the Missouri basin, water yields increase there. The BMRC GCM predicts sharply decreased precipitation and, hence, reduced water yields. Precipitation reductions are even greater in the Arkansas basin under BMRC as are the consequent water yield losses. GISS and UKTR climates lead to only moderate yield losses in the Arkansas. CO2-fertilization reverses these losses and yields increase slightly. CO2 fertilization increases recharge in the base (no climate change) case in both basins. Recharge is reduced under all three GCMs and severities of climate change. C1 Pacific NW Lab, Washington, DC USA. Pacific NW Lab, Richland, WA 99352 USA. Texas A&M Univ, Blackland Res Ctr, Temple, TX USA. ARS, USDA, Temple, TX USA. RP Rosenberg, NJ (reprint author), Pacific NW Lab, Washington, DC USA. RI Srinivasan, R/D-3937-2009 NR 34 TC 88 Z9 91 U1 5 U2 75 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD AUG PY 1999 VL 42 IS 4 BP 677 EP 692 DI 10.1023/A:1005424003553 PG 16 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 218VU UT WOS:000081574400004 ER PT J AU Wang, SQ Miller, DL Cernansky, NP Curran, HJ Pitz, WJ Westbrook, CK AF Wang, SQ Miller, DL Cernansky, NP Curran, HJ Pitz, WJ Westbrook, CK TI A flow reactor study of neopentane oxidation at 8 atmospheres: Experiments and modeling SO COMBUSTION AND FLAME LA English DT Article ID GAS-PHASE OXIDATION; RADICALS; ALKYL; AUTOIGNITION; COMBUSTION; CHEMISTRY; PRESSURES; ATM AB An existing detailed chemical kinetic reaction mechanism for neopentane oxidation [1] is applied to new experimental measurements taken in a flow reactor [2] operating at a pressure of 8 atm. The reactor temperature ranged from 620 K to 810 K and flow rates of the reactant gases neopentane, oxygen, and nitrogen were 0.285, 7.6, and 137.1 standard liter per minute (SLM), respectively, producing an equivalence ratio of 0.3. Initial simulations identified some deficiencies in the existing model and the paper presents modifications which included upgrading the thermodynamic parameters of alkyl radical and alkylperoxy radical species, adding an alternative isomerization reaction of hydroperoxy-neopentyl-peroxy, and a multistep reaction sequence for 2-methylpropan-2-yl radical with molecular oxygen. These changes improved the calculation for the overall reactivity and the concentration profiles of the following primary products: formaldehyde, acetone, isobutene; 3,3-dimethyloxetane, methacrolein, carbon monoxide, carbon dioxide, and water. Experiments indicate that neopentane shows negative temperature coefficient behavior similar to other alkanes, though it is not as pronounced as that shown by n-pentane for example. Modeling results indicate that this behavior is caused by the beta-scission of the neopentyl radical and the chain propagation reactions of the hydroperoxyl-neopentyl radical. (C) 1999 by The Combustion Institute. C1 Drexel Univ, Dept Mech Engn & Mech, Philadelphia, PA 19104 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Curran, HJ (reprint author), Drexel Univ, Dept Mech Engn & Mech, Philadelphia, PA 19104 USA. OI Curran, Henry/0000-0002-5124-8562 NR 44 TC 54 Z9 54 U1 1 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD AUG PY 1999 VL 118 IS 3 BP 415 EP 430 DI 10.1016/S0010-2180(99)00014-0 PG 16 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 206AV UT WOS:000080854600008 ER PT J AU Himmel, ME Ruth, MF Wyman, CE AF Himmel, ME Ruth, MF Wyman, CE TI Cellulase for commodity products from cellulosic biomass SO CURRENT OPINION IN BIOTECHNOLOGY LA English DT Review ID TRICHODERMA-REESEI; MICROCRYSTALLINE CELLULOSE; DIRECTED EVOLUTION; FUEL ETHANOL; HYDROLYSIS; MODEL; ENZYME; CELLOBIOHYDROLASES; PERSPECTIVE AB A vital objective for second millennium biotechnology will be the enzymatic conversion of renewable cellulosic biomass to inexpensive fermentable sugars; new and more efficient fermentation processes will convert this biological 'currency' to a variety of commodity products. Although early strides will be made using process development and engineering disciplines, mid-term and longer advances must rely heavily on insight gained through protein and metabolic engineering technologies. These challenging goats can be met most effectively by the full integration of academic, federal, and industrial efforts in teams that develop and apply new fundamental knowledge to key cost drivers. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Dartmouth Coll, Thayer Sch Engn, Hanover, NH 03755 USA. RP Himmel, ME (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM Michael_Himmel@nrel.gov; Mark_Ruth@nrel.gov; Charles.E.Wyman@Dartmouth.edu NR 45 TC 183 Z9 195 U1 2 U2 30 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0958-1669 J9 CURR OPIN BIOTECH JI Curr. Opin. Biotechnol. PD AUG PY 1999 VL 10 IS 4 BP 358 EP 364 DI 10.1016/S0958-1669(99)80065-2 PG 7 WC Biochemical Research Methods; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA 223EZ UT WOS:000081829100009 ER PT J AU Colvin, ME Sasaki, JC Tran, NL AF Colvin, ME Sasaki, JC Tran, NL TI Chemical factors in the action of phosphoramidic mustard alkylating anticancer drugs: Roles for computational chemistry SO CURRENT PHARMACEUTICAL DESIGN LA English DT Review ID INTERSTRAND CROSS-LINK; SEQUENCE SELECTIVE ALKYLATION; NITROGEN MUSTARDS; MOLECULAR-DYNAMICS; DUPLEX DNA; ISOPHOSPHORAMIDE MUSTARD; DEOXYGUANOSINE RESIDUES; AQUEOUS-SOLUTION; STRUCTURAL BASIS; CYCLOPHOSPHAMIDE AB The nitrogen mustard based DNA alkylating agents were the first effective anticancer agents and remain important drugs against many forms of cancer. More than fifty years of research on the nitrogen mustards has yielded a broad range of therapeutically useful compounds and a detailed knowledge of the biochemical mechanism of these drugs. Nevertheless, there is much ongoing research on the phosphosphoramidic and other nitrogen mustards to increase their potency and reduce their toxic and mutagenic side effects. To understand the existing nitrogen mustards, and to design the next generation of these drugs, more knowledge is needed about the effects of chemical modifications on their activation and selectivity. Because of the existing knowledge of these drugs, atomic-level chemical modeling can play an important role in the understanding of the phosphoramidic mustard compounds; however, it has not proved straight forward to directly relate the activity of these mustards with simple chemical properties such as bond lengths or atomic charges. Instead, quantum chemical simulations will be required to simulate the activation and alkylation reactions of these compounds, which will require the newest generation of quantum chemical and solvent modeling methods. Additionally, molecular dynamics simulations of the adducted DNA can provide data on the factors favoring crosslinking and its structural consequences. This review summarizes the extensive literature on the metabolism, activation, and action of the phosphoramidic mustards, with an emphasis on the roles that chemical modeling has and will play in the development of this important class of drugs. C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Div Mol & Struct Biol, Livermore, CA 94550 USA. RP Colvin, ME (reprint author), Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Div Mol & Struct Biol, Mailstop L-452, Livermore, CA 94550 USA. FU NCI NIH HHS [CA55861] NR 93 TC 10 Z9 10 U1 0 U2 3 PU BENTHAM SCIENCE PUBL BV PI HILVERSUM PA PO BOX 1673, 1200 BR HILVERSUM, NETHERLANDS SN 1381-6128 J9 CURR PHARM DESIGN JI Curr. Pharm. Design PD AUG PY 1999 VL 5 IS 8 BP 645 EP 663 PG 19 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA 241GQ UT WOS:000082874600007 PM 10469896 ER PT J AU Kim, YS Jett, JH Larson, EJ Penttila, JR Marrone, BL Keller, RA AF Kim, YS Jett, JH Larson, EJ Penttila, JR Marrone, BL Keller, RA TI Bacterial fingerprinting by flow cytometry: Bacterial species discrimination SO CYTOMETRY LA English DT Article DE bacteria fingerprinting; flow cytometry; DNA sizing ID FIELD GEL-ELECTROPHORESIS; FLUORESCENCE DETECTION; MASS-SPECTROMETRY; DNA; FRAGMENTS AB Background: A now cytometric measurement (FCM) technique has been developed to size DNA fragments. Individual fragments of a restriction digest of genomic DNA, stained with an intercalating dye, are passed through an ultrasensitive cytometer. The measured fluorescence intensity from each fragment is proportional to the fragment length. Methods: The isolation of bacterial genomic DNA and digestion by restriction enzymes were performed inside an agarose plug. Rare cutting enzymes were employed to produce a manageable number of DNA fragments. Electroelution was used to move the DNA fragments from the agarose plug into a solution containing polyamines to protect the DNA from shear-induced breakage. The DNA was stained with the bisintercalating dye thiazole orange homodimer and introduced into our ultrasensitive flow cytometer. A histogram of the fluorescence intensities (fingerprint) was constructed. Results: Gram-positive Bacillus globigii and Gramnegative bacteria Escherichia coli and Erwinia herbicola were distinguished by the fingerprint pattern of restriction fragments of their genomic DNA. DNA sizes determined by FCM are in good agreement with pulsed-field gel electrophoresis (PFGE) analysis. Flow cytometry requires only picogram quantities of purified DNA and takes less than 10 min for data collection and analysis. When the total sample preparation time is included, the analysis times for PFGE and ECM are similar (approximate to 3 days). Conclusions: FCM is an attractive technique for the identification of bacterial species. It is more sensitive and potentially much faster than PFGE. (C) 1999 Wiley-Liss, Inc. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. RP Keller, RA (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, MS M888, Los Alamos, NM 87545 USA. FU NCRR NIH HHS [RR-01315] NR 25 TC 21 Z9 23 U1 1 U2 9 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0196-4763 J9 CYTOMETRY JI Cytometry PD AUG 1 PY 1999 VL 36 IS 4 BP 324 EP 332 DI 10.1002/(SICI)1097-0320(19990801)36:4<324::AID-CYTO7>3.0.CO;2-K PG 9 WC Biochemical Research Methods; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 218XP UT WOS:000081578600007 PM 10404148 ER PT J AU Gorbarenko, SA Southon, JR AF Gorbarenko, SA Southon, JR TI Detailed dated paleoenvironmental changes of the Japan Sea during last glaciation-Holocene SO DOKLADY AKADEMII NAUK LA Russian DT Article ID OXYGEN ISOTOPES; LEVEL C1 Russian Acad Sci, Far E Div, Pacific Oceanol Inst, Vladivostok 690022, Russia. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Gorbarenko, SA (reprint author), Russian Acad Sci, Far E Div, Pacific Oceanol Inst, Vladivostok 690022, Russia. NR 14 TC 0 Z9 0 U1 0 U2 0 PU MEZHDUNARODNAYA KNIGA PI MOSCOW PA 39 DIMITROVA UL., 113095 MOSCOW, RUSSIA SN 0869-5652 J9 DOKL AKAD NAUK+ JI Dokl. Akad. Nauk PD AUG PY 1999 VL 367 IS 4 BP 541 EP 543 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 271DV UT WOS:000084579700028 ER PT J AU Kerstein, AR AF Kerstein, AR TI One-dimensional turbulence Part 2. Staircases in double-diffusive convection SO DYNAMICS OF ATMOSPHERES AND OCEANS LA English DT Article DE one-dimensional turbulence; unsteady simulation; interface formation ID STABLE SALINITY GRADIENT; INTERFACE; TRANSPORT; NUMBER; HEAT AB One-Dimensional Turbulence (ODT), a turbulence model implemented as an unsteady simulation, is applied to the diffusive regime of double-diffusive convection. For this application, no parameter adjustment or other empiricism is required, Computed component fluxes across heat-salt and sail-sugar interfaces are consistent with the Linden-Shirtcliffe picture, applicable at intermediate density ratios, and Newell's model of interface evolution at high density ratios. The experimentally observed onset of a variable regime at density ratios below 2 is reproduced, Simulations of interface formation in a bottom-heated salt-stabilized medium indicate that Fernando's scaling for interface stabilization height may also apply to the height of initial interface formation. The simulations generate staircases resembling those seen in laboratory experiments, and suggest a refinement of a scaling inferred from experiments. Computed results for a thermally forced configuration and an unforced, vertically homogeneous configuration are compared. (C) 1999 Published by Elsevier Science B.V. C1 Sandia Natl Labs, Combust Res Facil, Dept 8351, Livermore, CA 94551 USA. RP Kerstein, AR (reprint author), Sandia Natl Labs, Combust Res Facil, Dept 8351, MS 9051,7011 East Ave, Livermore, CA 94551 USA. NR 24 TC 20 Z9 21 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0265 J9 DYNAM ATMOS OCEANS JI Dyn. Atmos. Oceans PD AUG PY 1999 VL 30 IS 1 BP 25 EP 46 DI 10.1016/S0377-0265(99)00017-2 PG 22 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography GA 234QF UT WOS:000082495300002 ER PT J AU Scurlock, JMO Cramer, W Olson, RJ Parton, WJ Prince, SD AF Scurlock, JMO Cramer, W Olson, RJ Parton, WJ Prince, SD TI Terrestrial NPP: Toward a consistent data set for global model evaluation SO ECOLOGICAL APPLICATIONS LA English DT Article DE carbon cycle, global; modeling the global carbon cycle; net primary productivity; NPP data use for model validation; NPP field data, need for consistency ID CLIMATE-CHANGE; PRIMARY PRODUCTIVITY; SOIL CARBON; ATMOSPHERE; WORLDWIDE; DYNAMICS; IMPACT AB Progress in modeling the global carbon cycle is inhibited by the lack of a high-quality data set based upon field observations of net primary productivity (NPP) with which to calibrate, parameterize, and evaluate terrestrial biosphere models. Under the auspices of the Global Primary Production Data Initiative (GPPDI), an activity endorsed by the International Geosphere-Biosphere Program's Data and Information System, a small international workshop was held in Cincinnati, Ohio, USA, in December 1996 to address the problem of extrapolating sparse field observations of NPP to produce a consistent database representative of major biomes. We report the conclusions of this workshop and the goals of GPPDI-to further expand the existing data compilation, to agree upon consistent standards for cross-site comparisons and allometric relationships for various biome types, and to document methodologies for spatial extrapolation from point measurements to grid cells. The resulting NPP database will also have intrinsic value: global data are important for many ecological problems, and NPP is a kind of "pathfinder" for other ecological data sets. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Potsdam Inst Climate Impact Res, D-14412 Potsdam, Germany. Colorado State Univ, Nat Resource Ecol Lab, Ft Collins, CO 80523 USA. Univ Maryland, Dept Geog, College Pk, MD 20742 USA. RP Scurlock, JMO (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Cramer, Wolfgang/B-8221-2008 OI Cramer, Wolfgang/0000-0002-9205-5812 NR 37 TC 77 Z9 104 U1 5 U2 19 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1707 H ST NW, STE 400, WASHINGTON, DC 20006-3915 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD AUG PY 1999 VL 9 IS 3 BP 913 EP 919 DI 10.2307/2641338 PG 7 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 225QQ UT WOS:000081972600013 ER PT J AU Peters, EL Schultz, IR Newman, MC AF Peters, EL Schultz, IR Newman, MC TI Rubidium and cesium kinetics and tissue distributions in channel catfish (Ictalurus punctatus) SO ECOTOXICOLOGY LA English DT Article DE rubidium; cesium; kinetics; clearance-volume model; fish ID TROUT SALMO-GAIRDNERI; FRESH-WATER FISH; BROWN TROUT; RADIOCESIUM; ELIMINATION; METABOLISM; TURNOVER; PHARMACOKINETICS; RADIONUCLIDES; RESERVOIR AB We used a two-compartment, clearance volume-based model to examine rubidium and cesium pharmacokinetics in channel catfish (Ictalurus punctatus) after intravascular administration. We compared the apparent volumes of distribution in the central and peripheral compartments and the intercompartmental and whole-body clearances of both metals at 20.0 degrees C and 27.5 degrees C. Biological half-times of Rb were 15 to 16 d at both temperatures, but Cs biological half-times averaged 101 d and 85 d at 20.0 degrees C and 27.5 degrees C, respectively (5 to 7 times longer than those of Rb in the same individual). Both the intercompartmental and total body clearances of Rb were also 6 to 7 times greater than those of Cs. The apparent volumes of distribution for Rb in the central compartments were twice those of Cs and remained constant with temperature. The apparent volumes of distribution of both elements in peripheral compartments were large compared with their corresponding central compartments, and decreased by a similar extent with increased temperature. Cesium tissue to blood ratios were greatest for white muscle, with more than 85% of the Cs present in this tissue. Partitioning of Cs in peripheral tissues apparently decreased with increased temperature conditions. Our results indicate that application of pharmacokinetic modeling techniques can enhance studies of radionuclide kinetics by helping to identify rate-limiting processes within individuals that may control uptake and elimination. C1 Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Peters, EL (reprint author), Chicago State Univ, Dept Biol Sci, 9501 S King Dr, Chicago, IL 60628 USA. NR 43 TC 14 Z9 15 U1 0 U2 9 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0963-9292 J9 ECOTOXICOLOGY JI Ecotoxicology PD AUG PY 1999 VL 8 IS 4 BP 287 EP 300 DI 10.1023/A:1008981216690 PG 14 WC Ecology; Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 254DN UT WOS:000083596800005 ER PT J AU Baker, RJ Dewoody, JA Wright, AJ Chesser, RK AF Baker, RJ Dewoody, JA Wright, AJ Chesser, RK TI On the utility of heteroplasmy in genotoxicity studies: An example from Chornobyl SO ECOTOXICOLOGY LA English DT Article DE heteroplasmy; Chornobyl; ionizing radiation; mitochondrial DNA; Clethrionomys glareolus ID MITOCHONDRIAL-DNA; SEQUENCE HETEROPLASMY; GENE; CHERNOBYL; SEGREGATION; MUTATIONS; EVOLUTION; DYNAMICS; GENOTYPE; MAMMALS AB We examine the utility of mtDNA heteroplasmy in assessing genetic damage due to environmental insult. Site heteroplasmy was quantified in a 400 bp portion of the cytochrome b gene in voles from a contaminated area near Chornobyl, Ukraine and from a relative control site by examining pregnant females and their embryos. A four hundred base pair segment was sequenced from approximately ten clones from each mother and embryo. Taq and/or cloning mutations were evaluated to estimate technical error. Although the rates of substitutions in clonal variants for experimentals, biological controls and technical controls were 1 in 1,840 bp, 1 in 2,280 bp, and 1 in 3,333 bp, respectively, we could not reject the null hypothesis that the variants were the result of a single, combined, mutation rate. However, multiple substitutions and transversions were restricted to clones from the Chornobyl samples. Bootstrap analyses indicate that these aspects of variation were significantly different from the controls. Examination of the mitochondrial genome by cloning individual molecules for site heteroplasmy to estimate effects of pollution on mutation rate in free-living organisms appears to warrant additional study. C1 Texas Tech Univ, Dept Biol Sci, Lubbock, TX 79409 USA. Univ Georgia, Savannah River Ecol Lab, Athens, GA 30602 USA. Univ Georgia, Dept Genet, Athens, GA 30602 USA. RP Baker, RJ (reprint author), Texas Tech Univ, Dept Biol Sci, Lubbock, TX 79409 USA. RI DeWoody, James/C-4909-2008 OI DeWoody, James/0000-0002-7315-5631 NR 35 TC 17 Z9 18 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0963-9292 J9 ECOTOXICOLOGY JI Ecotoxicology PD AUG PY 1999 VL 8 IS 4 BP 301 EP 309 DI 10.1023/A:1008985300760 PG 9 WC Ecology; Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 254DN UT WOS:000083596800006 ER PT J AU Cornejo, JJ Munoz, FG Ma, CY Stewart, AJ AF Cornejo, JJ Munoz, FG Ma, CY Stewart, AJ TI Studies on the decontamination of air by plants SO ECOTOXICOLOGY LA English DT Article DE phytoremediation; VOCs; volatile organic pollutants; air cleansing by plants ID LEAVES; TRICHLOROETHYLENE; PHYTOREMEDIATION; FORMALDEHYDE AB We conducted laboratory tests with six species of plants to determine their ability to remove benzene, trichloroethylene (TCE) and toluene from air. The objective of this proof-of-principal study was to evaluate the idea that phytoremediation techniques might be used to lower the concentrations of indoor air pollutants, such as volatile or semi-volatile organic compounds. Plants were exposed to the pollutants singly or in mixtures in an airtight chamber, and concentrations of the pollutants in the chamber were monitored through time to assess plant effects on the pollutants. In several experiments, we measured air temperature and CO2, as well. Lower surfaces of leaves of several of the species we tested were also examined by scanning electron microscopy to determine stomate abundance and size, and to provide information about leaf-surface elemental composition (by X-ray emission spectroscopy). Several of the species demonstrated an extensive ability to remove benzene from air. Gas chromatography methods allowed a reasonably direct, continuous monitoring of the kinetics and overall efficiency of the pollutant-removal process. We found that pollutant removal efficiency varied in response to plant species and the pollutant. Of the pollutants tested, benzene was most efficiently removed from air by Pelargonium domesticum, Ficus elastica and Chlorophytum comosum. Kalanchoe blossfeldiana, a common ornamental plant, appeared to take up benzene selectively over toluene, and TCE was removed efficiently from the air by C. comosum. Pentane, sometimes used as an internal standard in GC/MS, was removed from air by at least four of the species. For C. comosum, TCE appeared to lower the removal rates of benzene and pentane. Low-vacuum scanning electron microscopy provided information on stomate size and density and permitted rapid initial elemental analysis of the plant-leaf surface by X-ray emission spectroscopy. Our results indicate that simple tests for pollutant uptake, morphological and chemical features of plants, and plant detoxification enzyme activity might be used in multivariate fashion to identify plant species capable of removing volatile or semi-volatile pollutants from air. C1 Univ Santiago Chile, Dept Quim Mat, Santiago, Chile. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Cornejo, JJ (reprint author), Univ Santiago Chile, Dept Quim Mat, Alameda 3363,Casilla 40,Correo 33, Santiago, Chile. OI stewart, arthur/0000-0003-1968-5997 NR 31 TC 27 Z9 39 U1 3 U2 33 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0963-9292 J9 ECOTOXICOLOGY JI Ecotoxicology PD AUG PY 1999 VL 8 IS 4 BP 311 EP 320 DI 10.1023/A:1008937417598 PG 10 WC Ecology; Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 254DN UT WOS:000083596800007 ER PT J AU Deng, HT Van Berkel, GJ AF Deng, HT Van Berkel, GJ TI A thin-layer electrochemical flow cell coupled on-line with electrospray-mass spectrometry for the study of biological redox reactions SO ELECTROANALYSIS LA English DT Article DE electrochemistry; mass spectrometry; electrospray; on-line; dopamine; tandem mass spectrometry; oxidation products; nucleophilic addition ID LIQUID-CHROMATOGRAPHY; GAS-PHASE; ONLINE; OXIDATION; CATECHOLAMINES; INTERFACE; PRODUCTS; DOPAMINE; BRAIN; IONS AB A three electrode thin-layer, flow-by electrode cell was coupled on-line with electrospray-mass spectrometry (i.e., EC/ES-MS) for the study of biological redox reactions. The cell made use of a commercially available 6.0 mm diameter, offset glassy carbon disk working electrode, a Ag/AgCl reference electrode, and a working/counter electrode spacing gasket (16 mu m), along with a home-built PEEK counter electrode block with a Pt foil (7.0mm wide) counter electrode (cell volume ca. 1.1 mu L). Off-line hydrodynamic voltammetry experiments and electrolytic conversion efficiency measurements using chronocoulometry were used to characterize the performance of the cell. On-line EC/ES-MS conversion efficiency was found consistent with the off-line results and the EC/ES-MS response time was measured as 5.1 s at a flow rate of 30 mu L/min and 2.4 s at 62 mu L/min. The use of this hybrid system for the study of the products of biologically relevant redox reactions was demonstrated using the oxidation of dopamine in aqueous CH3OH (pH 4.0) as a test case. Tandem mass spectrometry experiments provided evidence to conclude that the structure of the two major dopamine oxidation products observed in the ES mass spectra were 5,6-dihydroxyindoline and 5,6-hydroxyindole. Reaction of oxidized dopamine with the surrogate biogenic nucleophile benzene thiol resulted in the formation of mono-, di-, and tri-benzene thiol addition products. These spectra also indicated that the reaction of oxidized dopamine with benzene thiol was significantly faster than the intermolecular cyclization reaction of this intermediate, which normally produces 5,6-dihydroxyindoline. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Van Berkel, GJ (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 37 TC 89 Z9 89 U1 7 U2 30 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 1040-0397 J9 ELECTROANAL JI Electroanalysis PD AUG PY 1999 VL 11 IS 12 BP 857 EP 865 DI 10.1002/(SICI)1521-4109(199908)11:12<857::AID-ELAN857>3.0.CO;2-1 PG 9 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA 228TZ UT WOS:000082152900004 ER PT J AU Mukundan, R Brosha, EL Brown, DR Garzon, FH AF Mukundan, R Brosha, EL Brown, DR Garzon, FH TI Ceria-electrolyte-based mixed potential sensors for the detection of hydrocarbons and carbon monoxide SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID ZIRCONIA OXYGEN SENSOR; STABILIZED ZIRCONIA; OXIDE ELECTRODE AB Mixed potential sensors based on zirconia electrolytes have been extensively investigated for the detection of CO and hydrocarbons in oxygen-containing streams. In this paper, the response of a Pt/Ce0.8Gd0.2O1.9/Au sensor operating at 600 degrees C is reported for the first time and is compared to that of a Pt/stabilized zirconia (yttria-stabilized, YSZ)/Au sensor. The response of the ceria-electrolyte sensor was more stable and reproducible than that of the zirconia-electrolyte sensor. This difference in response has been attributed to an improvement in the oxygen reduction kinetics of the gold electrode on the ceria electrolyte. (C) 1999 The Electrochemical Society. S1099-0062(99)02-069-6. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Elect & Electrochem Mat & Devices Grp, Los Alamos, NM 87545 USA. RP Mukundan, R (reprint author), Univ Calif Los Alamos Natl Lab, Elect & Electrochem Mat & Devices Grp, POB 1663, Los Alamos, NM 87545 USA. NR 13 TC 65 Z9 66 U1 4 U2 18 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD AUG PY 1999 VL 2 IS 8 BP 412 EP 414 DI 10.1149/1.1390855 PG 3 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 203VG UT WOS:000080728300019 ER PT J AU Blackshear, P Brown, H Diver, R Epstein, M Harvey, B Hiroki, T Kappauf, T Karni, J Macdonald, F Murray, J Noring, J Palumbo, R Scherrer, H Scholl, K Sparrow, E Steinfeld, A Tamaura, Y Yogev, A Lior, N AF Blackshear, P Brown, H Diver, R Epstein, M Harvey, B Hiroki, T Kappauf, T Karni, J Macdonald, F Murray, J Noring, J Palumbo, R Scherrer, H Scholl, K Sparrow, E Steinfeld, A Tamaura, Y Yogev, A Lior, N TI A tribute to Dr. Edward A. Fletcher SO ENERGY LA English DT Biographical-Item C1 Univ Massachusetts, Amherst, MA 01003 USA. Univ Minnesota, Minneapolis, MN 55455 USA. Purdue Univ, W Lafayette, IN 47907 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Weizmann Inst Sci, IL-76100 Rehovot, Israel. Power Engineers Inc, Hailey, ID 83333 USA. Ford Motor Co, Dearborn, MI 48121 USA. Owens Corning R&D, Toledo, OH 43659 USA. Colorado Sch Mines, Golden, CO 80401 USA. Paul Scherrer Inst, Villigen, Switzerland. Valparaiso Univ, Valparaiso, IN USA. Univ Colorado, Boulder, CO 80309 USA. Tokyo Inst Technol, Tokyo, Japan. Univ Penn, Philadelphia, PA 19104 USA. RP Blackshear, P (reprint author), Univ Massachusetts, Amherst, MA 01003 USA. OI Steinfeld, Aldo/0000-0001-7797-686X NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-5442 J9 ENERGY JI Energy PD AUG PY 1999 VL 24 IS 8 BP 655 EP 656 PG 2 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA 231FJ UT WOS:000082297200001 ER PT J AU Greening, LA Ting, M Davis, WB AF Greening, LA Ting, M Davis, WB TI Decomposition of aggregate carbon intensity for freight: trends from 10 OECD countries for the period 1971-1993 SO ENERGY ECONOMICS LA English DT Article DE transportation; energy use; carbon dioxide emissions ID UNITED-STATES; TRANSPORTATION; EMISSIONS; ENERGY AB Historical patterns of aggregate carbon intensity from freight are different than those from other sectors. While aggregate carbon intensity declined for all other sectors, aggregate carbon intensity for freight increased. The Adaptive Weighted Divisia rolling base year index specification is applied to carbon emissions from the freight sector of 10 OECD countries for the period 1970-1993. Increases in aggregate carbon intensity for nine of the countries range from less than 20% to over 150% and may be primarily attributed to shifts in modal structure toward more carbon-intensive modes. These increases in aggregate carbon intensity are driven primarily by an increase in activity, which parallels the growth in GDP. Furthermore, changes in fuel price and vehicle purchase taxes do not appear to be effective instruments for reducing energy consumption for this end use. Alternative policy options, including less-carbon intensive fuels and technologies, and reduced congestion, appear to be better choices. (C) 1999 Elsevier Science B.V. All rights reserved. JEL classification: Q41. C1 Int Resources Grp, Washington, DC USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Energy & Environm, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Econ, Berkeley, CA 94720 USA. RP Greening, LA (reprint author), Int Resources Grp, Washington, DC USA. NR 28 TC 40 Z9 48 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0140-9883 J9 ENERG ECON JI Energy Econ. PD AUG PY 1999 VL 21 IS 4 BP 331 EP 361 DI 10.1016/S0140-9883(99)00010-9 PG 31 WC Economics SC Business & Economics GA 213PW UT WOS:000081283300004 ER PT J AU Gold, LS Manley, NB Slone, TH Rohrbach, L AF Gold, LS Manley, NB Slone, TH Rohrbach, L TI Supplement to the Carcinogenic Potency Database (CPDB): Results of animal bioassays published in the general literature in 1993 to 1994 and by the National Toxicology Program in 1995 to 1996 SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Review DE animal cancer test; carcinogenic potency; database; human carcinogen; monkey neoplasm; TD50 ID SPRAGUE-DAWLEY RATS; BUTYL ETHER MTBE; MALE F344 RATS; HEPATOCELLULAR-CARCINOMA; B6C3F1 MICE; CHRONIC TOXICITY; PEROXISOME PROLIFERATOR; CELL-PROLIFERATION; FISCHER-344 RATS; INDUCED HEPATOCARCINOGENESIS AB The Carcinogenic Potency Database (CPDB) is a systematic and unifying analysis of results of chronic, long-term cancer tests. This paper presents a supplemental plot of the CPDB, including 513 experiments on 157 test compounds published in the general literature in 1993 and 1994 and in Technical Reports of the National Toxicology Program in 1995 and 1996. The plot standardizes the experimental results (whether positive or negative for carcinogenicity), including qualitative data on strain, sex, route of compound administration, target organ, histopathology, and author's opinion and reference to the published paper, as well as quantitative data on carcinogenic potency, statistical significance, tumor incidence, dose-response curve shape, length of experiment, duration of dosing, and dose rate. A numerical description of carcinogenic potency, the TD50 is estimated for each set of tumor incidence data reported. When added to the data published earlier, the CPDB now includes results of 5,620 experiments on 1,372 chemicals that have been reported in 1,250 published papers and 414 National Cancer Institute/National Toxicology Program Technical Reports. The plot presented here includes detailed analyses of 25 chemicals tested in monkeys for up to 32 years by the National Cancer Institute. Half the rodent carcinogens that were tested in monkeys were not carcinogenic, despite usually strong evidence of carcinogenicity in rodents and/or humans. Our analysis of possible explanatory factors indicates that this result is due in pari to the fact that the monkey studies lacked power to detect an effect compared to standard rodent bioassays. Factors that contributed to the lack of power are the small number of animals on test; a stop-exposure protocol for model rodent carcinogens; in a few cases, toxic doses that resulted in stoppage of dosing or termination of the experiment; and in a few cases, low doses administered to monkeys or early termination of the experiment even though the doses were not toxic. Among chemicals carcinogenic in both monkeys and rodents, there is some support for target site concordance, but it is primarily restricted to liver tumors. Potency values are highly correlated between rodents and monkeys. The plot in this paper can be used in conjunction with the earlier results published in the CRC Handbook of Carcinogenic Potency and Genotoxicity Databases [Gold LS, Zeiger E, eds. Boca Raton FL:CRC Press, 1997] and with our web site (http;//potency.Berkeley edu), which includes a guide to the plot of the database, a complete description of the numerical index of carcinogenic potency (TD50), and a discussion of the sources of data, the rationale for the inclusion of particular experiments and particular target sites, and the conventions adopted in summarizing the literature Two summary tables permit easy access to the literature of animal cancer tests by target organ and by chemical. For readers using the CPDB extensively, a combined plot on diskette or other format is available from the first author. It includes all results published earlier and in this paper, ordered alphabetically by chemical. A SAS database is also available. C1 Univ Calif Berkeley, NIEHS Ctr, Div Biochem & Mol Biol, Berkeley, CA 94720 USA. EO Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA USA. RP Gold, LS (reprint author), Univ Calif Berkeley, NIEHS Ctr, Div Biochem & Mol Biol, 401 Barker Hall, Berkeley, CA 94720 USA. FU NIEHS NIH HHS [ESO1896] NR 181 TC 36 Z9 36 U1 1 U2 3 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD AUG PY 1999 VL 107 SU 4 BP 527 EP + PG 73 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 227RU UT WOS:000082094400001 PM 10421768 ER PT J AU Johnson, KP Stout, J Brisbin, IL Zink, RM Burger, J AF Johnson, KP Stout, J Brisbin, IL Zink, RM Burger, J TI Lack of demonstratable effects of pollutants on cyt b sequences in wood ducks from a contaminated nuclear reactor cooling pond SO ENVIRONMENTAL RESEARCH LA English DT Article ID EVOLUTION; EGGS; CHERNOBYL; MUTATIONS; PATTERNS; DYNAMICS AB The effects of low levels of radiation on DNA mutation rates are largely unknown for free-living vertebrates. In this study we investigated the effects of contamination from cooling ponds at a nuclear production facility in South Carolina on the mutation rates in mitochondrial DNA in wood ducks (Aix sponsa), Specifically, we sequenced a 433-bp portion of the cytochrome b gene from 18 female-offspring pairs of wood ducks from contaminated ponds and 2 female-offspring pairs from control ponds,Very low haplotype diversity was observed overall, and no case of mutation between female and offspring could be satisfactorily documented. This suggests that the levels of radioactive contamination in these cooling ponds have little effect on the mutation rate of mitochondrial DNA in these waterfowl and that mitochondrial DNA may not be as sensitive an indicator as previously anticipated. (C) 1999 Academic Press. C1 Univ Minnesota, Dept Ecol Evolut & Behav, St Paul, MN 55108 USA. Univ Minnesota, Bell Museum Nat Hist, St Paul, MN 55108 USA. Rutgers State Univ, Nelson Biol Labs, Piscataway, NJ USA. Environm & Occupat Hlth Sci Inst, Piscataway, NJ USA. Savannah River Ecol Lab, Aiken, SC USA. RP Johnson, KP (reprint author), Univ Minnesota, Dept Ecol Evolut & Behav, St Paul, MN 55108 USA. FU NIEHS NIH HHS [ESO 5022] NR 24 TC 3 Z9 3 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0013-9351 J9 ENVIRON RES JI Environ. Res. PD AUG PY 1999 VL 81 IS 2 BP 146 EP 150 DI 10.1006/enrs.1999.3969 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health GA 221QQ UT WOS:000081738100008 PM 10433846 ER PT J AU Moran, JE Oktay, S Santschi, PH Schink, DR AF Moran, JE Oktay, S Santschi, PH Schink, DR TI Atmospheric dispersal of (129)iodine from nuclear fuel reprocessing facilities SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID I-129 CONCENTRATIONS; HANFORD SITE; ENVIRONMENT; IODINE; PLANT; SAMPLES; CL-36 AB (191)\/(171)\ ratios measured in meteoric water and epiphytes from the continental United States are higher than those measured in coastal seawater or surface freshwater and suggest long-range atmospheric transport of (129)\ from the main source for the earth's surface inventory, viz., nuclear fuel reprocessing facilities. The median ratio for 14 meteoric water samples is 2100 x 10(-12), corresponding to a (129)\ concentration of 2.5 x 10(7) atoms/L, whereas 9 epiphyte samples have a median ratio of 1800 x 10(-12) Calculated deposition rates of (129)\ in the continental United States reveal that a small but significant fraction of the atmospheric releases from the nuclear fuel reprocessing facilities at Sellafield, England, and Cap de La Hague, France, is deposited after distribution by long-range transport. The inferred dominant mode of transport is easterly, within the troposphere, mainly in the form of the organic gas methyl iodide. C1 Texas A&M Univ, Dept Oceanog, College Stn, TX 77845 USA. Texas A&M Univ, Dept Oceanog, Galveston, TX 77551 USA. RP Moran, JE (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-231, Livermore, CA 94550 USA. RI Santschi, Peter/D-5712-2012 NR 42 TC 114 Z9 115 U1 1 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD AUG 1 PY 1999 VL 33 IS 15 BP 2536 EP 2542 DI 10.1021/es9900050 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 222XT UT WOS:000081811200026 ER PT J AU Johnson, SK Houk, LL Feng, JR Houk, RS Johnson, DC AF Johnson, SK Houk, LL Feng, JR Houk, RS Johnson, DC TI Electrochemical incineration of 4-chlorophenol and the identification of products and intermediates by mass spectrometry SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID WASTE-WATER TREATMENT; TITANIUM-DIOXIDE; SNO2 ANODES; OXIDATION; DEGRADATION; BENZOQUINONE; PHENOL; OXYGEN AB This report summarizes results obtained as part of a larger effort to demonstrate the applicability of electrolytic procedures for the direct anodic (oxidative) degradation of toxic organic wastes. We refer to this process as "electrochemical incineration" (ECI) because the ultimate degradation products, e.g., carbon dioxide, are equivalent to those achieved by thermal incineration processes. In this work, the ECI of 4-chlorophenol is achieved in an aqueous medium using a platinum anode coated with a quaternary metal oxide film containing Ti, Ru, Sn, and Sb oxides. The electrode is stable and active when used with a solid Nafion membrane without the addition of soluble supporting electrolyte. Liquid chromatography (LC), including reverse phase and ion exchange chromatography, is coupled with electrospray mass spectrometry (ES-MS) and used, along with gas chromatography-mass spectrometry (GCMS) and measurements of pH, chemical oxygen demand (COD), and total organic carbon (TOC), to study the reaction and identify the intermediate products from the ECI of Q-chlorophenol. Twenty-six intermediate products are identified and reported. The most abundant of these products are benzoquinone, 4-chlorocatechol, maleic acid, succinic acid, malonic acid, and the inorganic anions chloride, chlorate, and perchlorate. After 24 h of ECI, a solution that initially contained 108 ppm 4-chlorophenol yields only 1 ppm TOC with 98% of the original chlorine remaining in the specified inorganic forms. LC-ES-MS and direct infusion ES-MS detection limits are between 80 ppb and 4 ppm for these intermediate products. Elemental analysis of the electrolyzed solutions by inductively coupled plasma mass spectrometry ICP-MS showed that only trace amounts (<25 ppb) of the metallic elements comprising the metal oxide film were present in the solution. C1 Iowa State Univ, US DOE, Microanalyt Instrumentat Ctr, Dept Chem,Ames Lab, Ames, IA 50011 USA. RP Johnson, DC (reprint author), Iowa State Univ, US DOE, Microanalyt Instrumentat Ctr, Dept Chem,Ames Lab, Ames, IA 50011 USA. NR 28 TC 115 Z9 126 U1 1 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD AUG 1 PY 1999 VL 33 IS 15 BP 2638 EP 2644 DI 10.1021/es981045r PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 222XT UT WOS:000081811200041 ER PT J AU Conry, MJ MacNaeidhe, F AF Conry, MJ MacNaeidhe, F TI Comparative nutrient status of a peaty gleyed podzol and its plaggen counterpart on the Dingle peninsula in the south-west of Ireland SO EUROPEAN JOURNAL OF AGRONOMY LA English DT Article DE major elements; nutrient status; plaggen soil; trace elements AB A comparison of the nutrient status, in terms of both major nutrients and trace elements, of a sanded plaggen soil (Mollic Eutroplaggent) on the Dingle peninsula and its adjacent identical non-sanded peaty podzolised grey (Entic Haplaquod) was carried out. The results showed that the concentration of the major elements, phosphorus and potassium, and the secondary elements, calcium, magnesium and sodium, were substantially higher in the plaggen soil than its non-sanded counterpart. The concentrations of copper, zinc, boron and cobalt were also substantially greater in the plaggen soil, but the higher concentrations of copper, zinc and boron were attributed to agricultural practices rather than the sanding process. Manganese deficiency occurs regularly in manganese-sensitive crops grown on these alkaline plaggen soils. (C) 1999 Elsevier Science B.V. All rights reserved. C1 TEAGASC, Crops Res Ctr, Carlow, Ireland. TEAGASC, Johnstown Castle Res Ctr, Wexford, Ireland. RP Conry, MJ (reprint author), TEAGASC, Crops Res Ctr, Oak Pk, Carlow, Ireland. NR 18 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1161-0301 J9 EUR J AGRON JI Eur. J. Agron. PD AUG PY 1999 VL 11 IS 2 BP 85 EP 90 DI 10.1016/S1161-0301(99)00021-0 PG 6 WC Agronomy SC Agriculture GA 243FN UT WOS:000082986500001 ER PT J AU Wheldon, C Walker, PM D'Alarcao, R Chowdhury, P Pearson, CJ Seabury, EH Ahmad, I Carpenter, MP Cullen, DM Hackman, G Janssens, RVF Khoo, TL Nisius, D Reiter, P AF Wheldon, C Walker, PM D'Alarcao, R Chowdhury, P Pearson, CJ Seabury, EH Ahmad, I Carpenter, MP Cullen, DM Hackman, G Janssens, RVF Khoo, TL Nisius, D Reiter, P TI Identification of a high-K isomer in neutron-rich Ta-185 SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article AB A t(1/2)>1 ms, high-K isomeric state feeding a strongly coupled rotational band has been identified following the deep inelastic reaction U-283(92) + W-186(74) at 1600 MeV. Examination of gamma-ray and X-ray data combined with a g-factor analysis derived from in-band branching ratios suggests the assignment of the new states to the neutron-rich nucleus Ta-185(73). C1 Univ Surrey, Dept Phys, Guildford GU2 5XH, Surrey, England. Univ Massachusetts, Lowell, MA 01854 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Liverpool, Oliver Lodge Lab, Dept Phys, Liverpool L69 7ZE, Merseyside, England. RP Wheldon, C (reprint author), Univ Surrey, Dept Phys, Guildford GU2 5XH, Surrey, England. RI Wheldon, Carl/F-9203-2013; Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 8 TC 16 Z9 16 U1 1 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD AUG PY 1999 VL 5 IS 4 BP 353 EP 355 DI 10.1007/s100500050296 PG 3 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 233PA UT WOS:000082434200004 ER PT J AU Kruken, R Wang, Z Asztalos, SJ Becker, JA Bernstein, LA Clark, RM Deleplanque, MA Diamond, RM Fallon, P Fotiades, N Hauschild, K Lee, IY Macchiavelli, AO Schmid, GJ Stephens, FS Vetter, K AF Kruken, R Wang, Z Asztalos, SJ Becker, JA Bernstein, LA Clark, RM Deleplanque, MA Diamond, RM Fallon, P Fotiades, N Hauschild, K Lee, IY Macchiavelli, AO Schmid, GJ Stephens, FS Vetter, K TI Quadrupole moments of superdeformed bands in Tl-193 SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article ID NORMAL DEFORMED STATES; LIFETIME MEASUREMENTS; EXCITATION-ENERGIES; HG-194; YRAST; PB-194; PARITY; DECAY; SPINS AB Lifetimes of states in the two strongest superdeformed (SD) bands in Tl-193 were measured using the Doppler-shift attenuation method. The reaction Yb-176(Na-23,6n)Tl-193 at a beam energy of 129 MeV was used and gamma-rays were detected by the Gammasphere array. Quadrupole moments of 18.3(10) eb and 17.4(10) eb were extracted for SD bands 1 and 2, respectively, using the fractional Doppler-shifts of the SD transitions. The previously reported linking transitions of these SD bands to normal deformed near yrast levels could not be confirmed. No other candidates for linking transitions could be established. C1 Yale Univ, AW Wright Nucl Struct Lab, New Haven, CT 06520 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Rutgers State Univ, Dept Phys & Astron, New Brunswick, NJ 08903 USA. RP Kruken, R (reprint author), Yale Univ, AW Wright Nucl Struct Lab, New Haven, CT 06520 USA. RI Hauschild, Karl/A-6726-2009; Kruecken, Reiner/A-1640-2013 OI Kruecken, Reiner/0000-0002-2755-8042 NR 25 TC 7 Z9 7 U1 1 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD AUG PY 1999 VL 5 IS 4 BP 367 EP 370 DI 10.1007/s100500050298 PG 4 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 233PA UT WOS:000082434200006 ER PT J AU Kastner, J Petry, W Shapiro, SM Zheludev, A Neuhaus, J Roessel, T Wassermann, EF Bach, H AF Kastner, J Petry, W Shapiro, SM Zheludev, A Neuhaus, J Roessel, T Wassermann, EF Bach, H TI Influence of atomic order on TA(1)[110] phonon softening and displacive phase transition in Fe72Pt28 Invar alloys SO EUROPEAN PHYSICAL JOURNAL B LA English DT Article ID FE-PT ALLOYS; LATTICE-DYNAMICS; TEMPERATURE-DEPENDENCE; PRECURSOR PHENOMENA; PD ALLOY; TRANSFORMATION; FE3PT; NI AB The acoustic phonon dispersions of two Invar crystals Fe72Pt28, one ordered with the L1(2) (Cu3Au) structure, the other disordered fee, have been investigated between 3.4 K and 470 K by inelastic and elastic neutron scattering. For the ordered crystal, pronounced softening of the whole TA(1)[xi xi 0] phonon branch is observed on cooling below the Curie temperature. Particularly strong phonon softening at the M-point zone boundary of the L1(2) structure leads to a displacive, antiferrodistortive phase transi tion at low temperatures. For the disordered crystal, much weaker softening of the TA(1)[xi xi 0] phonons is observed and restricted to the region near title Brillouin zone center, where increasing elastic scattering with decreasing temperature indicates the growth of local tetragonal strain. This strain is considered as a typical precursor of the transformation to bet martensite. Specific heat measurements, performed at low temperatures on both crystals confirm the neutron scattering results and reveal considerable enhancement of the low energy phonon density of states in the ordered crystal. C1 Univ Duisburg Gesamthsch, Lab Tieftemp Phys, D-47048 Duisburg, Germany. Tech Univ Munich, Phys Dept E13, D-85747 Garching, Germany. Brookhaven Natl Lab, Upton, NY 11973 USA. Ruhr Univ Bochum, Inst Expt Phys 4, D-44780 Bochum, Germany. RP Kastner, J (reprint author), Univ Duisburg Gesamthsch, Lab Tieftemp Phys, D-47048 Duisburg, Germany. RI Petry, Winfried/K-4998-2016 OI Petry, Winfried/0000-0001-5208-7070 NR 35 TC 16 Z9 16 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6028 J9 EUR PHYS J B JI Eur. Phys. J. B PD AUG PY 1999 VL 10 IS 4 BP 641 EP 648 DI 10.1007/s100510050896 PG 8 WC Physics, Condensed Matter SC Physics GA 236BX UT WOS:000082579300006 ER PT J AU Detlefs, C Abernathy, DL Grubel, G Canfield, PC AF Detlefs, C Abernathy, DL Grubel, G Canfield, PC TI The magnetic structure of orthorhombic ErNi2B2C SO EUROPHYSICS LETTERS LA English DT Article ID X-RAY-SCATTERING; METAMAGNETIC TRANSITIONS; SUPERCONDUCTING LUNI2B2C; ANGULAR-DEPENDENCE; CRYSTAL-STRUCTURE; BORIDE CARBIDE; HONI2B2C; STATE; ORDER; POLARIZATION AB In a recent X-ray scattering experiment it was demonstrated that the magnetic ordering transition of ErNi2B2C at 6.0 K is accompanied by a structural distortion, which lowers the crystal symmetry from tetragonal to orthorhombic. In previous neutron magnetic scattering experiments, this lowering of the crystal lattice symmetry was not resolved. Since the magnetic modulations along the a and b crystallographic directions are equivalent in tetragonal, but not in orthorhombic systems, the magnetic structure determinations based on neutron data remained incomplete. We have performed a high-resolution non-resonant magnetic X-ray scattering experiment on a single crystal of ErNi2B2C to determine the magnetic structure. The magnetic modulation wave vector is (0.5537, 0, 0) and lies along the long side of the orthorhombic basal plane. C1 European Synchrotron Radiat Facil, F-38043 Grenoble, France. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. RP Detlefs, C (reprint author), European Synchrotron Radiat Facil, Boite Postale 220, F-38043 Grenoble, France. RI Detlefs, Carsten/B-6244-2008; Abernathy, Douglas/A-3038-2012; Canfield, Paul/H-2698-2014 OI Detlefs, Carsten/0000-0003-2573-2286; Abernathy, Douglas/0000-0002-3533-003X; NR 33 TC 19 Z9 19 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD AUG 1 PY 1999 VL 47 IS 3 BP 352 EP 357 DI 10.1209/epl/i1999-00396-3 PG 6 WC Physics, Multidisciplinary SC Physics GA 225FW UT WOS:000081948600012 ER PT J AU Rasmussen, KO Cai, D Bishop, AR Gronbech-Jensen, N AF Rasmussen, KO Cai, D Bishop, AR Gronbech-Jensen, N TI Localization in a nonlinear disordered system SO EUROPHYSICS LETTERS LA English DT Article ID WEAKLY COUPLED OSCILLATORS; SCHRODINGER-EQUATION; HAMILTONIAN NETWORKS; DISCRETE LATTICES; BREATHERS; STABILITY; EXISTENCE; EXCITATIONS; PROPAGATION; MEDIA AB The interplay between nonlinearity and disorder is studied in a discrete one-dimensional Schrodinger system. Using a two-point correlation function we demonstrate that the preferred state of the system comprises narrow intrinsic localized states corresponding to the intrinsic localized states of the ordered system. The essence of the interplay between disorder and nonlinearity is found to reside in the nucleation process of the localized states. We emphasize the role of different classes (focusing and defocusing) of nonlinearity in enhancing or suppressing localization induced by disorder. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NYU, Courant Inst Math Sci, New York, NY 10012 USA. RP Rasmussen, KO (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Rasmussen, Kim/B-5464-2009 OI Rasmussen, Kim/0000-0002-4029-4723 NR 27 TC 24 Z9 24 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD AUG PY 1999 VL 47 IS 4 BP 421 EP 427 DI 10.1209/epl/i1999-00405-1 PG 7 WC Physics, Multidisciplinary SC Physics GA 229WX UT WOS:000082219700003 ER PT J AU Kim, SS Choi, IG Kim, SH Yu, YG AF Kim, SS Choi, IG Kim, SH Yu, YG TI Molecular cloning, expression, and characterization of a thermostable glutamate racemase from a hyperthermophilic bacterium, Aquifex pyrophilus SO EXTREMOPHILES LA English DT Article DE Aquifex pyrophilus; molecular cloning; glutamate racemase; overexpression; thermostability ID COMPLETE GENOME SEQUENCE; ASPARTATE RACEMASE; ESCHERICHIA-COLI; CRYSTAL-STRUCTURE; GENE; LACTOBACILLUS; DEHYDROGENASE; PURIFICATION; RESOLUTION; ARCHAEON AB A gene encoding glutamate racemase has been cloned from Aquifex: pyrophilus, a hyperthermophilic bacterium, and expressed in Escherichia coli. The A. pyrophilus glutamate racemase is composed of 254 amino acids and shows high homology with glutamate racemase from Escherichia coli, Bacillus subtilis, or Lactobacillus brevis, This racemase converts L- or D-glutamate to D- or L-glutamate, respectively, but not other amino acids such as alanine, aspartate, and glutamine. The cloned gene was expressed and the protein was purified to homogeneity. The A. pyrophilus racemase is present as a dimer but it oligomerizes as the concentration of salt is increased. The K-m and k(cat) values of the overexpressed A. pyrophilus glutamate racemase for the racemization of L-glutamate to the D-form and the conversion of D-glutamate to the L-form were measured as 1.8 +/- 0.4 mM and 0.79 +/- 0.06 s(-1) or 0.50 +/- 0.07 mM and 0.25 +/- 0.01 s(-1), respectively. Complete inactivation of the racemase activity by treatment with cysteine-modifying reagents suggests that cysteine residues may be important for activity. The protein shows strong thermostability in the presence of phosphate ion, and it retains more than 50% of its activity after incubation at 85 degrees C for 90 min. C1 Korea Inst Sci & Technol, Struct Biol Ctr, Seoul, South Korea. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Yu, YG (reprint author), Korea Inst Sci & Technol, Struct Biol Ctr, POB 131, Seoul, South Korea. RI Choi, In-Geol/F-3152-2013 NR 28 TC 13 Z9 14 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1431-0651 J9 EXTREMOPHILES JI Extremophiles PD AUG PY 1999 VL 3 IS 3 BP 175 EP 183 DI 10.1007/s007920050114 PG 9 WC Biochemistry & Molecular Biology; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA 227YF UT WOS:000082107000002 PM 10484173 ER PT J AU Schoof, RA Yost, LJ Eickhoff, J Crecelius, EA Cragin, DW Meacher, DM Menzel, DB AF Schoof, RA Yost, LJ Eickhoff, J Crecelius, EA Cragin, DW Meacher, DM Menzel, DB TI A market basket survey of inorganic arsenic in food SO FOOD AND CHEMICAL TOXICOLOGY LA English DT Article DE inorganic arsenic; dietary exposures; arsenic in food ID JAPANESE ADULTS; TOTAL DIET; ELEMENTS; EXPOSURE AB Dietary arsenic intake estimates based on surveys of total arsenic concentrations appear to be dominated by intake of the relatively non-toxic, organic arsenic forms found in seafood. Concentrations of inorganic arsenic in food have not been not well characterized. Accurate dietary intake estimates for inorganic arsenic are needed to support studies of arsenic's status as an essential nutrient, and to establish background levels of exposure to inorganic arsenic. In the market basket survey reported here, 40 commodities anticipated to provide at least 90% of dietary inorganic arsenic intake were identified. Four samples of each commodity were collected. Total arsenic was analysed using an NaOH digestion and inductively coupled plasma-mass spectrometry. Separate aliquots were analysed for arsenic species using an HCl digestion and hydride atomic absorption spectroscopy. Consistent with earlier studies, total arsenic concentrations (all concentrations reported as elemental arsenic per tissue wet weight) were highest in the seafoods sampled (ranging from 160 ng/g in freshwater fish to 2360 ng/g in saltwater fish). In contrast, average inorganic arsenic in seafood ranged from less than 1 ng/g to 2 ng/g. The highest inorganic arsenic values were found in raw rice (74 ng/g), followed by flour (11 ng/g), grape juice (9 ng/g) and cooked spinach (6 ng/g). Thus, grains and produce are expected to be significant contributors to dietary inorganic arsenic intake. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Exponent, Bellevue, WA USA. ENVIRON, Arlington, VA USA. Battelle Marine Sci, Sequim, WA USA. Elf Atochem N Amer Inc, Philadelphia, PA USA. Univ Calif Irvine, Irvine, CA 92717 USA. RP Schoof, RA (reprint author), Exponent, Bellevue, WA USA. NR 24 TC 294 Z9 315 U1 8 U2 58 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0278-6915 J9 FOOD CHEM TOXICOL JI Food Chem. Toxicol. PD AUG PY 1999 VL 37 IS 8 BP 839 EP 846 DI 10.1016/S0278-6915(99)00073-3 PG 8 WC Food Science & Technology; Toxicology SC Food Science & Technology; Toxicology GA 239JW UT WOS:000082765800004 PM 10506007 ER PT J AU Shaing, KC Aydemir, AY Cheng, ET Peng, M AF Shaing, KC Aydemir, AY Cheng, ET Peng, M TI Self-sustained steady state tokamak plasmas SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT International Workshop on Spherical Torus (ST) Volumetric Neutron Source (VNS) and Applications, in Conjunction with the 1997 US/Russian Federation Exchange IL 3D on the Volumetric Neutron Source Design Study and Review CY OCT 13-15, 1997 CL DEL MAR, CALIFORNIA DE tokamak; steady-state plasma; plasma pressure ID BOOTSTRAP-CURRENT; EQUILIBRIA AB Self-sustained steady-state tokamak equilibria for National Spherical Torus Experiment (NSTX) and Spherical Torus-Volume Neutron Source (ST-VNS) are presented. It is demonstrated that the amount of the pressure gradient driven current which includes the bootstrap current and the diamagnetic current is comparable to the designed current specification in these devices. A possible startup sequence by increasing plasma pressure is also illustrated. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Univ Texas, Inst Fus Studies, Austin, TX 78712 USA. TSI Res Inc, Solana Beach, CA 92075 USA. Princeton Univ, Plasma Phys Lab, Princeton, NJ 08544 USA. RP Shaing, KC (reprint author), Univ Texas, Inst Fus Studies, Austin, TX 78712 USA. NR 10 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD AUG PY 1999 VL 45 IS 3 BP 259 EP 264 DI 10.1016/S0920-3796(99)00009-5 PG 6 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 235VR UT WOS:000082563700002 ER PT J AU Sviatoslavsky, IN Cheng, ET Cerbone, RJ Peng, YKM Galambos, JD Strickler, DJ Wang, XR AF Sviatoslavsky, IN Cheng, ET Cerbone, RJ Peng, YKM Galambos, JD Strickler, DJ Wang, XR TI Mechanical design considerations of the centerpost for a spherical torus volumetric neutron source SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT International Workshop on Spherical Torus (ST) Volumetric Neutron Source (VNS) and Applications, in Conjunction with the 1997 US/Russian Federation Exchange IL 3D on the Volumetric Neutron Source Design Study and Review CY OCT 13-15, 1997 CL DEL MAR, CALIFORNIA DE center post; neutral beams; spherical torus; volumetric neutron source AB The mechanical and thermal design issues of the centerpost (CP) for a spherical torus based volumetric neutron source (ST-VNS) is described. It is intended to provide a test bed for developing nuclear technologies as well as for qualifying blanket designs for use in fusion devices. As scoped out, the VNS is capable of staged operation from a neutron wall loading of 0.5-5.0 MW/m(2) as the physics and engineering design assumptions are raised from modest to aggressive levels. Design margins are ensured since operation will be adequate at a wall loading of 2 MW/m(2). The device has a major radius of 1.07 m, a minor radius of 0.77 m for an aspect ratio of 1.4, an elongation of 3, triangularity of 0.6 and has a naturally diverted plasma. It can be driven with neutral beams (NB) or ICRF. In the NE driven case, the plasma current is 11.1 MA, and in the ICRF case it is 13.2 MA. The magnetic field at the plasma major radius is 2.13 T and 2.55 T for the NE and the ICRF cases, respectively. This ST-VNS utilizes a single turn unshielded normal conducting CP fabricated from dispersion strengthened Cu, is 15.5 m long, has a diameter of 0.55 m at the midplane, a diameter of 1.2 m at the extremities and, in the ICRF driven case, carries a current of 13.6 MA. For the same case, the ohmic heating at the start of operation is 153 MW, increasing to 178 MW after 3 full power years. Thermal hydraulics, stress analysis and effects of transmutation on the CP have been determined, and a procedure for replacing the CP with minimal down time is described. (C) 1999 Published by Elsevier Science S.A. All rights reserved. C1 Univ Wisconsin, Madison, WI 53706 USA. TSI Res Inc, Solana Beach, CA 92075 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. RP Sviatoslavsky, IN (reprint author), Univ Wisconsin, 1500 Engn Dr, Madison, WI 53706 USA. NR 5 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD AUG PY 1999 VL 45 IS 3 BP 281 EP 293 DI 10.1016/S0920-3796(99)00011-3 PG 13 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 235VR UT WOS:000082563700004 ER PT J AU Galambos, JD Strickler, DJ Peng, YKM AF Galambos, JD Strickler, DJ Peng, YKM TI Systems cost and performance analysis for a spherical torus-based volume neutron source SO FUSION ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT International Workshop on Spherical Torus (ST) Volumetric Neutron Source (VNS) and Applications, in Conjunction with the 1997 US/Russian Federation Exchange IL 3D on the Volumetric Neutron Source Design Study and Review CY OCT 13-15, 1997 CL DEL MAR, CALIFORNIA DE neutron source; spherical torus; systems analysis ID TOKAMAK AB A cost and performance analysis of a spherical torus-based volume neutron source (ST-VNS) is performed using the SUPERCODE systems code. An ST-VNS, proposed as a reduced-cost option for testing the nuclear technologies necessary for tokamak power reactors, will cost about 25% of the construction cost of the International Thermonuclear Experimental Reactor Engineering Design Activities (ITER-EDA) when it is operating in an initial test phase with 0.5 MW m(-2) wall load. Advanced operation at 5 MW m(-2) wall load is possible with surface elongation kappa = 3, safety factor q(95) = 10, confinement enhancement factor H = 2.3, and Troyon beta limit beta(N) = 5%, at a direct cost of about 30% that of the ITER-EDA. There is a narrow region beta(N) and H space which is useful for attaining high neutron wall loads. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. RP Galambos, JD (reprint author), Oak Ridge Natl Lab, POB 2008,MS 6218, Oak Ridge, TN 37830 USA. NR 13 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD AUG PY 1999 VL 45 IS 3 BP 333 EP 341 DI 10.1016/S0920-3796(99)00015-0 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 235VR UT WOS:000082563700008 ER PT J AU Alagramam, KN Kwon, HY Cacheiro, NLA Stubbs, L Wright, CG Erway, LC Woychik, RP AF Alagramam, KN Kwon, HY Cacheiro, NLA Stubbs, L Wright, CG Erway, LC Woychik, RP TI A new mouse insertional mutation that causes sensorineural deafness and vestibular defects SO GENETICS LA English DT Article ID MYOSIN-VIIA GENE; UNCONVENTIONAL MYOSIN; RECESSIVE DEAFNESS; HEARING-LOSS; MICE; MUTAGENESIS AB This article describes a new recessive insertional mutation in the transgenic line TgN2742Rpw that causes deafness and circling behavior in mice. Histologic analysis revealed virtually complete loss of the cochlear neuroepithelium (the organ of Corti) in adult mutant mice. In association with the neuroepithelial changes, there is a dramatic reduction of the cochlear nerve supply. Adult mutants also show morphological defects of the vestibular apparatus, including degeneration of the saccular neuroepithelium and occasional malformation of utricular otoconia. Audiometric evaluations demonstrated that the mice displaying the circling phenotype are completely deaf. Molecular analysis of this mutant line revealed that the transgenic insertion occurred without creating a large deletion of the host DNA sequences. The mutant locus was mapped to a region on mouse chromosome 10, where other spontaneous, recessive mutations causing deafness in mice have been mapped. C1 Case Western Reserve Univ, Rainbow Babies & Childrens Hosp, Dept Pediat, Cleveland, OH 44106 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Human Genome, Livermore, CA 94550 USA. Univ Texas, SW Med Ctr, Dept Otorhinolaryngol, Dallas, TX 75235 USA. Univ Cincinnati, Dept Biol Sci, Cincinnati, OH 45221 USA. RP Woychik, RP (reprint author), Parke Davis Lab Mol Genet, 1501 Harbor Bay Pkwy, Alameda, CA 94502 USA. OI Stubbs, Lisa/0000-0002-9556-1972 FU NIDCD NIH HHS [1RO1-DC03420] NR 36 TC 24 Z9 24 U1 0 U2 2 PU GENETICS PI BALTIMORE PA 428 EAST PRESTON ST, BALTIMORE, MD 21202 USA SN 0016-6731 J9 GENETICS JI Genetics PD AUG PY 1999 VL 152 IS 4 BP 1691 EP 1699 PG 9 WC Genetics & Heredity SC Genetics & Heredity GA 224GL UT WOS:000081889600040 PM 10430593 ER PT J AU Cao, YC Kang, HL Xu, XQ Wang, M Dho, SH Huh, JR Lee, BJ Kalush, F Bocskai, D Ding, Y Tesmer, JG Lee, J Moon, E Jurecic, V Baldini, A Weier, HU Doggett, NA Simon, MI Adams, MD Kim, UJ AF Cao, YC Kang, HL Xu, XQ Wang, M Dho, SH Huh, JR Lee, BJ Kalush, F Bocskai, D Ding, Y Tesmer, JG Lee, J Moon, E Jurecic, V Baldini, A Weier, HU Doggett, NA Simon, MI Adams, MD Kim, UJ TI A 12-Mb complete coverage BAC contig map in human chromosome 16p13.1-p11.2 SO GENOME RESEARCH LA English DT Article ID FACTOR-BASED VECTOR; PHYSICAL MAP; HUMAN DNA; GENOME; CONSTRUCTION; STRATEGY; LIBRARY; YEAST AB We have constructed a complete coverage BAC contig map that spans a 12-Mb genomic segment in the human chromosome 16p13.1-p11.2 region. The map consists of 68 previously mapped STSs and 289 BAC clones, 51 of which-corresponding to a total of 7.721 Mb of genomic DNA-have been sequenced, and provides a high resolution physical map of the region. Contigs were initially built based mainly on the analysis of STS contents and restriction fingerprint patterns of the clones. To dose the gaps, probes derived from BAC clone ends were used to screen deeper BAC libraries. Clone end sequence data obtained from chromosome 16-specific BACs, as well as from public databases, were used for the identification of BACs that overlap with fully sequenced BACs by means of sequence match. This approach allowed precise alignment of clone overlaps in addition to restriction fingerprint comparison. A freehand contig drawing software tool was developed and used to manage the map data graphically and generate a real scale physical map. The map we present here is similar to 3.5 x deep and provides a minimal tiling path that covers the region in an array of contigous, overlapping BACs. C1 CALTECH, Div Biol, Pasadena, CA 91125 USA. Seoul Natl Univ, Inst Mol Biol & Genet, Seoul, South Korea. Inst Genom Res, Rockville, MD 20850 USA. Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Human Genome Studies, Los Alamos, NM 87545 USA. Ajou Univ, Dept Sci Biol, Suwon 441749, South Korea. Baylor Coll Med, Inst Mol Genet, Houston, TX 77030 USA. Univ Calif Berkeley, Div Life Sci, OE Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Kim, UJ (reprint author), CALTECH, Div Biol, Pasadena, CA 91125 USA. RI genes, anthony/F-2541-2012 FU NHGRI NIH HHS [HG01464-01] NR 22 TC 18 Z9 18 U1 0 U2 1 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 USA SN 1088-9051 J9 GENOME RES JI Genome Res. PD AUG PY 1999 VL 9 IS 8 BP 763 EP 774 PG 12 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA 227DL UT WOS:000082063000010 PM 10447511 ER PT J AU Nagy, KL Cygan, RT Hanchar, JM Sturchio, NC AF Nagy, KL Cygan, RT Hanchar, JM Sturchio, NC TI Gibbsite growth kinetics on gibbsite, kaolinite, and muscovite substrates: Atomic force microscopy evidence for epitaxy and an assessment of reactive surface area SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID SOLUTION SATURATION STATE; PRECIPITATION KINETICS; DIAGENETIC MODIFICATION; DISSOLUTION KINETICS; WEATHERING REACTIONS; ALUMINUM SPECIATION; CRYSTAL-CHEMISTRY; AQUEOUS-SOLUTION; CALCITE GROWTH; ABERT LAKE AB New experimental data for gibbsite growth on powdered kaolinite and single crystal muscovite and published data for gibbsite growth on gibbsite powders at 80 degrees C in pH3 solutions show that all growth rates obey the same linear function of saturation slate provided that reactive surface area is evaluated for each mineral substrate. Growth rate (mol m(-2) s(-1)) is expressed by Rate(ppt) = (1.9 +/- 0.2) X 10(-10)\Delta G(r)\/ RT(0.90+/-0.01), which applies to the range of saturation states from Delta G(r) = 0 to 8.8 kJ mol(-1), where Delta G(r) = RT[ln(Q/K)] for the reaction Al3+ + 3H(2)O = Al(OH)(3) + 3H(+), and equilibrium defined as Delta G(r) = 0 was previously determined. Identification of the growth phase as gibbsite was confirmed by rotating anode powder x-ray diffraction. Rates an kaolinite were determined using steady-state measured changes between inlet and outlet solutions in single-pass stirred-flow experiments. Rates on muscovite were determined by measuring the volume of precipitated crystals in images obtained by Tapping Mode(TM) atomic force microscopy (TMAFM). In deriving the single growth rate law, reactive surface area was evaluated for each substrate mineral. Total BET surface area was used for normalizing rates of gibbsite growth onto powdered gibbsite. Eight percent of the BET surface area, representing the approximate amount occupied by the aluminum octahedral sheet exposed at crystal edges, was used for powdered kaolinite. The x - y area of the TMAFM images of the basal surface was used for single crystal muscovite. Linearity of growth rates with saturation state suggests that the dominant nucleation and growth mechanisms are two dimensional. Such mechanisms are supported by observations of the morphologies of gibbsite crystals grown on muscovite at Delta G(r) = 8.8 kJ mol(-1). The morphologies include (1) apparent epitaxial films as determined by hexagonal outlines of edges and thicknesses of 30 to 40 Angstrom, (2) elongate crystals 30 to 40 Angstrom thick aligned with the structure of the distorted Si-tetrahedral sheet of the 2M, muscovite, and (3) micrometer-scale three-dimensional clumps of intergrown crystals. Reactive surface area as defined now for heterogeneous crystal growth in reactive-transport models must be modified to include substrates other than that of the growing mineral and to account for the role of structural and chemical controls on epitaxial nucleation and growth. Copyright (C) 1999 Elsevier Science Ltd. C1 Sandia Natl Labs, Dept Geochem, Albuquerque, NM 87185 USA. Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Nagy, KL (reprint author), Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA. EM kathryn.nagy@colorado.edu NR 71 TC 37 Z9 37 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 1999 VL 63 IS 16 BP 2337 EP 2351 DI 10.1016/S0016-7037(99)00118-0 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 239KR UT WOS:000082767700002 ER PT J AU Blencoe, JG Seitz, JC Anovitz, LM AF Blencoe, JG Seitz, JC Anovitz, LM TI The CO2-H2O system. II. Calculated thermodynamic mixing properties for 400 degrees C, 0-400 MPa SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID REDLICH-KWONG EQUATION; H2O-CO2 MIXTURES; CARBON-DIOXIDE; HIGH-PRESSURE; FUNDAMENTAL EQUATION; CH4-CO2-H2O SYSTEM; RATIONAL FUNCTIONS; HIGH-TEMPERATURES; FLUID MIXTURES; 500 BARS AB An excess molar volume (V-ex)-explicit virial equation, and two empirical V-ex expressions developed from experimentally determined densities, were used to calculate excess Gibbs free energies (G(ex)) and activity-composition (a-X) relations for CO2-H2O fluids at 400 degrees C, 0-400 MPa. Excess Gibbs free energies are continuously positive and asymmetric toward H2O at all pressures up to 400 MPa, rising to peak values of approximately 1300, 1800, 2000 and 2100 J mol(-1) at 50, 100, 200 and 400 MPa, respectively. Calculated activities for H2O and CO2 vary correspondingly, increasing substantially from 0 to 100 MPa, moderately from 100 to 200 MPa, and slightly from 200 to 400 MPa. In addition, because G(ex) is asymmetric toward H2O, a-X relations for H2O are distinctly different from those for CO2. These results indicate that CO2-H2O fluids are strongly nonideal at 400 degrees C and all pressures above similar to 30 MPa, despite the fact that peak values for V-ex decrease from similar to 50 cm(3).mol(-1) at 30 MPa to similar to 1 cm(3).mol(-1) at 200 MPa, and remain small to pressures at least as high as 500 MPa. Excess Gibbs free energies and a-X relations for CO2-H2O fluids at 400 degrees C and pressures to 400 MPa calculated from modified Redlich-Kwong and Lee-Kesler equations of state generally suggest significantly smaller positive deviations from ideality. Copyright (C) 1999 Elsevier Science Ltd. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Blencoe, JG (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008,Bldg 4500-S, Oak Ridge, TN 37831 USA. RI Anovitz, Lawrence/P-3144-2016 OI Anovitz, Lawrence/0000-0002-2609-8750 NR 63 TC 12 Z9 14 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG PY 1999 VL 63 IS 16 BP 2393 EP 2408 DI 10.1016/S0016-7037(98)00296-8 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 239KR UT WOS:000082767700006 ER PT J AU Niitsuma, H Fehler, M Jones, R Wilson, S Albright, J Green, A Baria, R Hayashi, K Kaieda, H Tezuka, K Jupe, A Wallroth, T Cornet, F Asanuma, H Moriya, H Nagano, K Phillips, WS Rutledge, J House, L Beauce, A Alde, D Aster, R AF Niitsuma, H Fehler, M Jones, R Wilson, S Albright, J Green, A Baria, R Hayashi, K Kaieda, H Tezuka, K Jupe, A Wallroth, T Cornet, F Asanuma, H Moriya, H Nagano, K Phillips, WS Rutledge, J House, L Beauce, A Alde, D Aster, R TI Current status of seismic and borehole measurements for HDR/HWR development SO GEOTHERMICS LA English DT Article DE seismology; microearthquakes; logging; hot dry rock; HDR/HWR; induced seismicity ID TRIAXIAL HODOGRAM; GEOTHERMAL RESERVOIR; ACOUSTIC-EMISSION; WAVE VELOCITIES; SOURCE LOCATION; FENTON HILL; NEW-MEXICO; EARTHQUAKES; EVENTS; STRESS AB Seismic and borehole measurements provide significant information about HDR/HWR reservoirs that is useful for reservoir development, reservoir characterization, and performance evaluation. Both techniques have been widely used during all HDR/HWR development projects. Seismic measurements have advanced from making passive surface measurements during hydraulic fracturing to making passive observation from multiple boreholes during all phases of HDR/HWR development, as well as active seismic measurements to probe regions of the reservoir deemed to be of interest. Seismic data provide information about reservoir extent, locations and orientations of significant fractures, and areas of thermal drawdown. Recent advances include the ability to examine structures within the seismically active zone using statistics-based techniques and methods such as seismic tomography. Seismic method is the only means to obtain direct information about reservoir characteristics away from boreholes. Borehole measurements provide high-resolution information about reservoir characteristics in the vicinity of the borehole. The ability to make borehole measurements has grown during the course of HDR/HWR development as high temperature tools have been developed. Temperature logging, televiewer logs, and electrical property measurements have been made and shown to provide useful information about locations of fractures intersecting wellbores, and regions where water leaves and enters injection and production wellbores, respectively. (C) 1993 CNR Published by Elsevier Science Ltd. All rights reserved. C1 Tohoku Univ, Sendai, Miyagi 9808579, Japan. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Camborne Sch Mines Assoc Ltd, Herniss TR10 9DU, Penryn, England. Socomine, F-67250 Soultz Sous Forets, France. Cent Res Inst Elect Power Ind, Abiko, Chiba 2701166, Japan. Japan Petr Explorat Co Ltd, JAPEX Res Ctr, Chiba 2610025, Japan. Chalmers Univ Technol, S-41296 Gothenburg, Sweden. Inst Phys Globe, F-75252 Paris 05, France. Muroran Inst Technol, Muroran, Hokkaido 0508585, Japan. Bur Rech Geol & Minieres, F-45060 Orleans 2, France. Nambe Geophys Inc, Santa Fe, NM 87501 USA. New Mexico Tech, Socorro, NM 87801 USA. RP Niitsuma, H (reprint author), Tohoku Univ, Sendai, Miyagi 9808579, Japan. RI Aster, Richard/E-5067-2013 OI Aster, Richard/0000-0002-0821-4906 NR 79 TC 5 Z9 5 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0375-6505 J9 GEOTHERMICS JI Geothermics PD AUG-OCT PY 1999 VL 28 IS 4-5 BP 475 EP 490 DI 10.1016/S0375-6505(99)00024-3 PG 16 WC Energy & Fuels; Geosciences, Multidisciplinary SC Energy & Fuels; Geology GA 235VE UT WOS:000082562600003 ER PT J AU Murphy, H Brown, D Jung, R Matsunaga, I Parker, R AF Murphy, H Brown, D Jung, R Matsunaga, I Parker, R TI Hydraulics and well testing of engineered geothermal reservoirs SO GEOTHERMICS LA English DT Article DE hot dry rocks; hot wet rocks; HDR; reservoir ID TRACER TESTS; ROCK; ROSEMANOWES; FLOW AB In most engineered reservoirs the water to extract the geothermal energy must be supplied, i.e., forced into the reservoir, rather than merely extracted as is common for conventional geothermal reservoirs. One operational hydraulic parameter of great interest is the impedance, which measures how much pressure is required to force water at unit flow rate through the reservoir. For practical purposes, the impedance should be less than 1 MPa s/l, and economic competitiveness with conventional reservoirs requires values one tenth as large. Most engineered reservoirs operated to date have met the upper requirement, and some are approaching the lower. Another parameter of great practical interest is the water loss rate, i.e. the difference between the rates of water injected and produced. Water losses and impedance are very pressure-dependent, but impedance is inversely so-high pressure increases water loss, but decreases the impedance. Hence operators may select strategies to meet their requirements. In some tight rock formations such as those at the Fenton Hill, USA, reservoir, the water loss rate may be so small that the pressure may be maximized to reduce impedance and increase energy production. In more permeable rock formations, the water losses may be quite high, so pressure and energy production may have to be limited. But in some cases, e.g. the reservoir at Soultz, France, there may be enough native permeability and water in place that more water actually maybe extracted with downhole pumps from the reservoir than is injected. (C) 1999 CNR. Published by Elsevier Science Ltd. AU rights reserved. C1 Colorado Sch Mines, Golden, CO 80401 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Bundesanstalt Geowissensch & Rohstoffe, D-3000 Hannover, Germany. Natl Inst Resources & Environm, Tsukuba, Ibaraki, Japan. CSM Associates, Cornwall, England. RP Murphy, H (reprint author), Colorado Sch Mines, Golden, CO 80401 USA. NR 36 TC 17 Z9 19 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0375-6505 J9 GEOTHERMICS JI Geothermics PD AUG-OCT PY 1999 VL 28 IS 4-5 BP 491 EP 506 DI 10.1016/S0375-6505(99)00025-5 PG 16 WC Energy & Fuels; Geosciences, Multidisciplinary SC Energy & Fuels; Geology GA 235VE UT WOS:000082562600004 ER PT J AU Brown, D DuTeaux, R Kruger, P Swenson, D Yamaguchi, T AF Brown, D DuTeaux, R Kruger, P Swenson, D Yamaguchi, T TI Fluid circulation and heat extraction front engineered geothermal reservoirs SO GEOTHERMICS LA English DT Article DE hot dry rock; HDR; HWR; reservoir ID ROCK; EARTHQUAKES; FLOW AB A large amount of fluid circulation and heat extraction (i.e., thermal power production) research and testing has been conducted on engineered geothermal reservoirs in the past 15 years. In confined reservoirs, which best represent the original Hot Dry Rock concept, the flow distribution at any given time is primarily determined by three parameters: (1) the nature of the interconnected network of pressure-stimulated joints and open fractures within the flow-accessible reservoir region, (2) the mean pressure in the reservoir, and (3) the cumulative amount of fluid circulation-and therefore reservoir cooling-that has occurred. For an initial reservoir rock temperature distribution and mean fluid outlet temperature, the rate of heat extraction (i.e., thermal power) is at first only a function of the production flow rate, since the production temperature can be expected to remain essentially constant for some time (months, or even years). However, as reservoir circulation proceeds, the production temperature will eventually start to decline, as determined by the mean effective joint spacing and the total flow-accessible (i.e., heat-transfer) volume of the reservoir. The rate of heat extraction, which depends on the production flow rate, can also vary with time as a result of continuing changes in the flow distribution arising from reservoir cooling. The thermal power of engineered reservoirs can most readily be increased by increasing the production flow rate, as long as this does not lead to premature cooldown, the development of short-circuit flow paths, or excessive water losses. Generally, an increase in now rate can be accomplished by increasing the injection pressure within limits. This strategy increases the driving pressure drop across the reservoir and the mean reservoir pressure, which in turn reduces the reservoir flow impedance by increasing the amount of joint dilation. However, the usefulness of this strategy is limited to reservoir operating pressures below the fracture extension pressure, and may lead to excessive water losses, particularly in less-confined reservoirs. Under such conditions, a downhole production-well pump may be employed to increase productivity by recovering more of the injected fluid at lower mean reservoir operating pressures. (C) 1999 Published by Elsevier Science Ltd on behalf of CNR. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Stanford Univ, Stanford, CA 94305 USA. Kansas State Univ, Manhattan, KS 66506 USA. RP Brown, D (reprint author), Univ Calif Los Alamos Natl Lab, MSD 443, Los Alamos, NM 87545 USA. NR 36 TC 25 Z9 28 U1 2 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0375-6505 J9 GEOTHERMICS JI Geothermics PD AUG-OCT PY 1999 VL 28 IS 4-5 BP 553 EP 572 DI 10.1016/S0375-6505(99)00028-0 PG 20 WC Energy & Fuels; Geosciences, Multidisciplinary SC Energy & Fuels; Geology GA 235VE UT WOS:000082562600008 ER PT J AU Abe, H Duchane, DV Parker, RH Kuriyagawa, M AF Abe, H Duchane, DV Parker, RH Kuriyagawa, M TI Present status and remaining problems of HDR/HWR system design SO GEOTHERMICS LA English DT Article DE hot dry rock; HDR; HWR; reservoir; design AB HDR/HWR can be one of the major sources of energy for the world in the 21st century because of the size of HDR/HWR resources and the environmental benefits offered by clean HDR/HWR energy. Over the last 25 years, significant advances have been made in the creation and operation of stimulated reservoirs, but little is yet known about the details of joint structure within the body of the reservoir. Continued developments and improvements to the technologies that support HDR/HWR development are essential to increase our understanding of these reservoirs. (C) 1999 CNR. Published by Elsevier Science Ltd. All rights reserved. C1 Natl Inst Resources & Environm, Tsukuba, Ibaraki 3058569, Japan. Tohoku Univ, Aoba Ku, Sendai, Miyagi 9800845, Japan. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CSMA, Cornwall TR10 9DU, England. RP Kuriyagawa, M (reprint author), Natl Inst Resources & Environm, Tsukuba, Ibaraki 3058569, Japan. NR 13 TC 7 Z9 8 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0375-6505 J9 GEOTHERMICS JI Geothermics PD AUG-OCT PY 1999 VL 28 IS 4-5 BP 573 EP 590 DI 10.1016/S0375-6505(99)00029-2 PG 18 WC Energy & Fuels; Geosciences, Multidisciplinary SC Energy & Fuels; Geology GA 235VE UT WOS:000082562600009 ER PT J AU Brown, DW Duchane, DV AF Brown, DW Duchane, DV TI Scientific progress on the Fenton Hill HDR project since 1983 SO GEOTHERMICS LA English DT Article DE hot dry rock; HDR; fracturing; reservoir; Fenton Hill; USA AB The modern HDR concept originated at the Los Alamos National Laboratory and was first demonstrated at Fenton Hill, New Mexico (USA). Experience gained during the development of the deeper HDR reservoir at Fenton Hill clearly showed that HDR reservoirs are formed by opening pre-existing, but sealed, multiply-connected joint sets. Subsequent flow testing indicated that sustained operation of HDR systems under steady-state conditions is feasible. The most significant remaining HDR issues are related to economics and locational flexibility. Additional field test sites are needed to advance the understanding of HDR technology so that the vast potential of this resource can be economically realized around the world. (C) 1999 Published by Elsevier Science Ltd on behalf of CNR. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Brown, DW (reprint author), Univ Calif Los Alamos Natl Lab, MS D443, Los Alamos, NM 87544 USA. NR 9 TC 11 Z9 16 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0375-6505 J9 GEOTHERMICS JI Geothermics PD AUG-OCT PY 1999 VL 28 IS 4-5 BP 591 EP 601 DI 10.1016/S0375-6505(99)00030-9 PG 11 WC Energy & Fuels; Geosciences, Multidisciplinary SC Energy & Fuels; Geology GA 235VE UT WOS:000082562600010 ER PT J AU Stow, SH AF Stow, SH TI Ethics: Creating guidelines for the geosciences SO GEOTIMES LA English DT Editorial Material C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Stow, SH (reprint author), Oak Ridge Natl Lab, 1055 Commerce Pk Dr,Suite 100, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 USA SN 0016-8556 J9 GEOTIMES JI Geotimes PD AUG PY 1999 VL 44 IS 8 BP 5 EP 5 PG 1 WC Geosciences, Multidisciplinary SC Geology GA 221XQ UT WOS:000081753200004 ER PT J AU Jordan, DN Zitzer, SF Hendrey, GR Lewin, KF Nagy, J Nowak, RS Smith, SD Coleman, JS Seeman, JR AF Jordan, DN Zitzer, SF Hendrey, GR Lewin, KF Nagy, J Nowak, RS Smith, SD Coleman, JS Seeman, JR TI Biotic, abiotic and performance aspects of the Nevada Desert Free-Air CO2 Enrichment (FACE) Facility SO GLOBAL CHANGE BIOLOGY LA English DT Article DE Ambrosia dumosa; CO2; FACE; Larrea tridentata; Lycium sp.; Mojave Desert ID WINTER ANNUALS; DIOXIDE; FIELD AB Arid and semiarid climates comprise roughly 40% of the earth's terrestrial surface. Deserts are predicted to be extremely responsive to global change because they are stressful environments where small absolute changes in water availability or use represent large proportional changes. Water and carbon dioxide fluxes are inherently coupled in plant growth. No documented global change has been more substantial or more rapid than the increase in atmospheric CO2. Free Air CO2 Enrichment (FACE) technology permits manipulation of CO2 in intact communities without altering factors such as light intensity or quality, humidity or wind. The Nevada Desert FACE Facility (NDFF) consists of three 491 m(2) plots in the Mojave Desert receiving 550 mu L L-1 CO2, and six ambient plots to assess both CO2 and fan effects. The shrub community was characterized as a Larrea-Ambrosia-Lycium species complex. Data are reported through 12 months of operation. C1 Univ Nevada, Dept Biol Sci, Las Vegas, NV 89154 USA. Desert Res Inst, Las Vegas, NV 89119 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Nevada, Reno, NV 89557 USA. Univ Nevada, Desert Res Inst, Reno, NV 89506 USA. RP Jordan, DN (reprint author), Univ Nevada, Dept Biol Sci, Mail Stop 4004, Las Vegas, NV 89154 USA. NR 22 TC 86 Z9 89 U1 3 U2 12 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1354-1013 J9 GLOB CHANGE BIOL JI Glob. Change Biol. PD AUG PY 1999 VL 5 IS 6 BP 659 EP 668 DI 10.1046/j.1365-2486.1999.00255.x PG 10 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 220FY UT WOS:000081655000004 ER PT J AU Garbesi, K Robinson, AL Sextro, RG Nazaroff, WW AF Garbesi, K Robinson, AL Sextro, RG Nazaroff, WW TI Radon entry into houses: The importance of scale-dependent permeability SO HEALTH PHYSICS LA English DT Article DE soil; Rn-222, indoor; modeling, dose assessment; sampling ID SOIL-GAS; TRANSPORT; BASEMENTS; PRESSURE; AIR AB Soil permeability to air can increase substantially with measurement length scale. We tested the hypothesis that the scale effect could resolve large model underpredictions of radon and soil-gas entry into two experimental basement structures located in natural sandy-loam soil at a field site in Pen Lomond, CA. Previously, the model input for permeability at the site had been assessed based on 0.5-m scale measurements. After determining the soil-structure interaction scale (system scale) to be similar to 3 m, the model input was changed to reflect 3-m scale permeability measurements. This adjustment reduced unacceptably large model underpredictions, of a factor of 3 to 5, to a range near that of acceptable experimental error, 20 to 40%, The permeability scale effect may explain large and persistent model underestimates of radon entry into real houses, The results argue strongly for determining permeability at a length scale consistent with that of the system under study. C1 San Jose State Univ, Dept Environm Studies, San Jose, CA 95192 USA. Carnegie Mellon Univ, Dept Engn & Publ Policy, Pittsburgh, PA 15213 USA. Carnegie Mellon Univ, Dept Mech Engn, Pittsburgh, PA 15213 USA. Lawrence Berkeley Natl Lab, Indoor Environm Dept, Environm & Energy Technol Div, Berkeley, CA USA. Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. RI Nazaroff, William/C-4106-2008; Robinson, Allen/I-5713-2012; Robinson, Allen/M-3046-2014 OI Nazaroff, William/0000-0001-5645-3357; Robinson, Allen/0000-0003-1053-7090; Robinson, Allen/0000-0002-1819-083X NR 33 TC 12 Z9 12 U1 0 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD AUG PY 1999 VL 77 IS 2 BP 183 EP 191 DI 10.1097/00004032-199908000-00008 PG 9 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 256MJ UT WOS:000083728800008 PM 12877340 ER PT J AU Chen, SY Ranek, N Kamboj, S Hensley, J Wallo, A AF Chen, SY Ranek, N Kamboj, S Hensley, J Wallo, A TI Authorized release of DOE's non-real property: Process and approach SO HEALTH PHYSICS LA English DT Article DE decontamination; recycling; operational topic; safety standards AB The U.S. Department of Energy's (DOE's) environmental cleanup activities will generate large amounts of non-real (personal) property over the next few decades. Although much of this material does not contain above-background concentrations of residual radioactive material, some does not contain above-background concentrations. In many cases, property containing or potentially containing above-background concentrations of residual radioactive material has been disposed of by burial. However, some of the property may be expensive equipment or devices that are still useful, and the incentive to recover them for reuse is high. Other property may be valuable metals, such as nickel, copper, or high-quality stainless steel, which can easily be recycled. Yet another category of property that will be involved is bulky material, such as concrete and carbon steel, which will require considerable space for burial. Although the values of these latter materials may riot be significant, recycling presents an attractive option for alleviating limited burial capacity and ever-increasing disposal costs at licensed or authorized disposal facilities. Authorized release provisions far non-real property are contained in Order DOE 5400.5, which DOE has proposed to be codified in Title 10, Part 834 of the Code of Federal Regulations (10 CFR 834) and in related guidance. The Department has also issued (for use and comment) the Draft Handbook for Controlling Release for Reuse or Recycle of Property Containing Residual Radioactive Material. As described in the handbook, authorized release can be accomplished using a step-by-step process. The process emphasizes application of the as-low-as-reasonably-achievable (ALARA) concept to derive release limits. This process involves identifying viable alternatives, followed by dose calculations and an optimization (cost/benefit) analysis to arrive at a preferred release alternative. Demonstration that a release alternative is ALARA noes Rot have to be elaborate if the individual and collective doses are small (on the order of a few mrem and person-rem per year). The approach outlined in the handbook also Regulatory stakeholder participation and the need to coordinate with the U.S. Nuclear Regulatory Commission or the responsible Agreement State to ensure that DOE-approved releases will trot result in an unlimited release of properly that is subject to NRC licensing requirements. C1 Argonne Natl Lab, Environm Assessment Div, Argonne, IL 60439 USA. US Dept Energy, Washington, DC USA. EM sychen@anl.gov NR 24 TC 3 Z9 3 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD AUG PY 1999 VL 77 IS 2 SU S BP S40 EP S48 DI 10.1097/00004032-199908001-00007 PG 9 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 260BK UT WOS:000083928300007 ER PT J AU Koelker, DL Johnson, WH Metcalf, JH AF Koelker, DL Johnson, WH Metcalf, JH TI Tritium source identification following the mood of a weapons-effects tunnel SO HEALTH PHYSICS LA English DT Article DE tritium; weapons; contamination; air sampling AB During a routine quarterly monitoring of a mothballed weapons-effects testing tunnel, a volume of 150 m(3) of contaminated water was found to be impounded by a concrete dam near the tunnel entrance. After the apparent source of the flooding was located and abated, water levels behind the darn quickly returned to normal. Subsequent monitoring showed that the level of tritium in the flood water was not consistent with We flood source. A simplistic equilibrium experiment was conducted and tracked for 4 mo in an attempt to locate other possible sources of tritium. Bottles of uncontaminated water were exposed to the tunnel atmosphere hr order to identify locations of elevated airborne tritium. The experiment identified areas containing contaminated purge water from previous water sampling operations arm a drain line sump as the likely sources of the elevated tritium content of the flood water A review of tunnel design and operational procedures supported this conclusion. C1 Nevada Operat Off, Def Special Weapons Agency, Mercury, NV 89023 USA. Univ Nevada, Dept Hlth Phys, Las Vegas, NV 89154 USA. Sandia Natl Labs, Mercury, NV 89023 USA. EM dskaway@yahoo.com NR 5 TC 2 Z9 2 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD AUG PY 1999 VL 77 IS 2 SU S BP S18 EP S23 DI 10.1097/00004032-199908001-00004 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 260BK UT WOS:000083928300004 ER PT J AU Romero, LL Hoffman, JM Foltyn, EM Buhl, TE AF Romero, LL Hoffman, JM Foltyn, EM Buhl, TE TI Operational comparison of bubble dosimetry with albedo thermoluminescent dosimetry for a selected group of Pu-238 workers SO HEALTH PHYSICS LA English DT Article DE Pu-238; dosimetry; thermoluminescent dosimetry; safety standards ID DETECTORS AB Personnel neutron dosimetry continues to be a difficult science due to the lack of availability of robust passive dosimeters that exhibit tissue equivalent, or near tissue equivalent response. The dosimeter most used for neutron dosimetry in the United States remains the albedo thermoluminescent dosimeter (TLD). Track-etch and bubble dosimeters generally have a more favorable energy response than albedo dosimeters but are more difficult and expensive to use. This paper is an operational study that compares the use of albedo TLDs with bubble dosimeters to determine whether bubble dosimeters do provide a useful daily tool to achieve as low as reasonably achievable (ALARA) goals that can yield measurements close to the dose-of-record from TLD. A group of workers working on the radioisotope thermoelectric generators (RTGs) for the National Aeronautics Space Administration (NASA) Cassini space mission wore both bubble dosimeters and albedo dosimeters over a period from 1993 through 1996. The bubble dosimeters were issued and read on a daily basis and the data were used as an ALARA tool. The personnel albedo dosimeter was processed on a monthly basis and used as the dose-of-record. The results of this study indicated that cumulative bubble dosimetry results agreed with whole-body albedo dosimetry results within about 37%. However, it was observed that there is a significant variability of the results on an individual basis both month-to-month and from one individual to another. C1 Univ Calif Los Alamos Natl Lab, Hlth Phys Measurement Grp ESH4, Los Alamos, NM 87545 USA. EM leonardr@lanl.gov NR 6 TC 2 Z9 2 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD AUG PY 1999 VL 77 IS 2 SU S BP S9 EP S17 DI 10.1097/00004032-199908001-00003 PG 9 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 260BK UT WOS:000083928300003 ER PT J AU Vargo, GJ Dasgupta, A Lentz, RC Neal, JK AF Vargo, GJ Dasgupta, A Lentz, RC Neal, JK TI STREAM and WPS-tools for improving worker safety at Chornobyl SO HEALTH PHYSICS LA English DT Article DE decontamination; Chornobyl; safety standards; computers AB On 26 April 1986, Chornobyl's Unit 4 reactor exploded during a test of the plant's turbine-generator system. The reactor core was destroyed. The explosion and subsequent fires dispersed large amounts of radioactive material in the form of gases and dust particles. In an effort to localize radioactivity and temporarily preserve the Unit 4, "Shelter" was constructed over the remains of the reactor. However, the destroyed unit, which contains about 190 tons of irradiated nuclear fuel, is undergoing degradation due to exposure to the environment. This has resulted in the generation of radioactive dust. Ukraine, and the G-7 countries, the G-7 countries include United states, Great Britain, Canada, France, Germany, Japan and Italy, have agreed on a plan to stabilize the shelter by building a new protective structure and by removing portions of the existing Shelter to ensure its long-term stability. The United States has committed to improve worker safety at the Shelter by reducing radiation doses to workers. As part of the continuing efforts to achieve dose reduction for site personnel at the Shelter, Delphinus Engineering, under contract from Pacific Northwest National Laboratory (PNNL) operated by Batelle, installed and implemented STREAM or System for Tracking Radiation, Engineering, Activities and Materials. STREAM is both a multimedia database system and a decision support system that was developed as a "tool" for management and staff to enhance and/or facilitate productivity, safety, improve communications and training. The STREAM data-base is utilized to store and manage information relevant for decontamination and decommissioning (D&D) activities. STREAM's decision support system, referred to as the Work Planning System (WPS) allows planning of manned entries into the facility. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Delphinus Engn, Eddystone, PA 19022 USA. EM vargo@pnl.gov NR 1 TC 2 Z9 2 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD AUG PY 1999 VL 77 IS 2 SU S BP S24 EP S31 DI 10.1097/00004032-199908001-00005 PG 8 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 260BK UT WOS:000083928300005 ER PT J AU Vickers, LD Eifert, EJ AF Vickers, LD Eifert, EJ TI The staging program for plutonium pits at the USDOE Pantex Plant SO HEALTH PHYSICS LA English DT Article DE plutonium; ALARA; radiation risk; radiation safety AB The United States Department of Energy (U.S. DOE) Pantex Plant serves as the staward of the nation's stockpile of plutonium pits. A plutonium pit is the main nuclear charge in a nuclear weapon (warhead or bomb). A plutonium pit is a hollow sphere of plutonium metal that is hermetically sealed by a cladding of stainless steel. Pantex Plant secures the common defense and national security of the United States by safely staging plutonium pits in a manner which protects the health and safety of employees, public, and the environment. C1 US DOE, Pantex Plant, Risk Management Dept, Amarillo, TX 79120 USA. EM lvickers@pantex.com NR 5 TC 1 Z9 1 U1 0 U2 3 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD AUG PY 1999 VL 77 IS 2 SU S BP S49 EP S54 DI 10.1097/00004032-199908001-00008 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 260BK UT WOS:000083928300008 ER PT J AU Efroymson, RA Suter, GW AF Efroymson, RA Suter, GW TI Finding a niche for soil microbial toxicity tests in ecological risk assessment SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Article DE assessment endpoint; microorganism; soil; soil contamination ID FATTY-ACID PROFILES; HEAVY-METALS; TRICHLOROETHYLENE; MICROORGANISMS; COMMUNITIES; TOLUENE AB Soil microbial toxicity tests are seldom used in ecological risk assessments or in the development of regulatory criteria in the U.S. The primary reason is the lack of an explicit connection between these tests and assessment endpoints. Soil microorganisms have three potential roles with respect to ecological assessment endpoints: properties of microbial communities may be endpoints; microbial responses may be used to estimate effects on plant production; and microbial responses may be used as surrogates for responses of higher organisms. Rates of microbial processes are important to ecosystem function, and thus should be valued by regulatory agencies. However, the definition of the microbial assessment endpoint is often an impediment to its use in risk assessment. Decreases in rates are not always undesirable. Processes in a nutrient cycle are particularly difficult to define as endpoints, because what constitutes an adverse effect on a process is dependent on the rates of others. Microbial tests may be used as evidence in an assessment of plant production, but the dependence of plants on microbial processes is rarely considered. As assessment endpoints are better defined in the future, microbial ecologists and toxicologists should be provided with more direction for developing appropriate microbial tests. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. US EPA, Natl Ctr Environm Assessment, Cincinnati, OH 45268 USA. RP Efroymson, RA (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. OI Efroymson, Rebecca/0000-0002-3190-880X NR 33 TC 11 Z9 11 U1 0 U2 4 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 USA SN 1080-7039 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD AUG PY 1999 VL 5 IS 4 BP 715 EP 727 PG 13 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 233BD UT WOS:000082404900010 ER PT J AU Grazier, KR Newman, WI Kaula, WM Hyman, JM AF Grazier, KR Newman, WI Kaula, WM Hyman, JM TI Dynamical evolution of planetesimals in the outer solar system - I. The Jupiter/Saturn zone SO ICARUS LA English DT Article ID SHORT-PERIOD COMETS; ORIGINAL DISTRIBUTION; STABLE ORBITS; ASTEROIDS; SATURN AB We report on numerical simulations designed to understand the distribution of small bodies in the Solar System and the winnowing of planetesimals accreted from the early solar nebula. The primordial planetesimal swarm evolved in a phase space divided into regimes by separatrices which define their trajectories and fate. This sorting process is driven by the energy and angular momentum and continues to the present day. We reconsider the existence and importance of stable niches in the Jupiter/Saturn zone using highly accurate numerical techniques based on high-order optimized multistep integration schemes coupled to roundoff error minimizing methods. We repeat the investigations of W.M. Weibel et al. (Icarus 83, 382-390, 1990) with one hundred thousand massless particles-nearly 10(3) time more particles than our 1990 investigation. Previous studies of the Jupiter/Saturn zone have employed only hundreds of particles, usually starting on circular and zero inclination orbits. By employing 10(5) particles on both inclinded and eccentric orbits, we can perform a near-exhaustive search for test particle stability as a function of initial orbital elements. The increase in the numbers of test particles also facilitates robust statistical inference and comparison with analytic results. In our simulations, we observed three stages in the planetesimal dynamics. At the start of the simulation many planetesimals are quickly eliminated by close approaches to Jupiter or Saturn. Next there is a gravitational relaxation phase where the surviving particles are exponentially eliminated by random gravitational encounters with Jupiter or Saturn. Finally, the only long-lived particles in the simulation were initially located either at a Lagrange point or in an orbit nearly commensurable with Jupiter or Saturn. We conclude that although niches for planetesimal material are rare, extremely high-accuracy long-duration simulations employing many particles will be able to capture even the qualitative nature of early Solar System planetesimal evolution. (C) 1999 Academic Press. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Math, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Grazier, KR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Newman, William/E-5918-2011 OI Newman, William/0000-0002-9835-1428 NR 47 TC 25 Z9 25 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD AUG PY 1999 VL 140 IS 2 BP 341 EP 352 DI 10.1006/icar.1999.6146 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 239EB UT WOS:000082754900007 ER PT J AU Grazier, KR Newman, WI Varadi, F Kaula, WM Hyman, JM AF Grazier, KR Newman, WI Varadi, F Kaula, WM Hyman, JM TI Dynamical evolution of planetesimals in the outer solar system - II. The Saturn/Uranus and Uranus/Neptune zones SO ICARUS LA English DT Article ID SECULAR RESONANCES; ORBITS; STABILITY; PLANETS; NEPTUNE; REGION; URANUS; BELT AB We report on numerical simulations exploring the dynamical stability of planetesimals in the gaps between the outer Solar System planets. We search for stable niches in the Saturn/Uranus and Uranus/Neptune zones by employing 10,000 massless particles-many more than previous studies in these two zones-using high-order optimized multistep integration schemes coupled with roundoff error minimizing methods. An additional feature of this study differing from its predecessors, is the fact that our initial distributions contain particles on orbits which are both inclined and noncircular. These initial distributions were also Gaussian distributed such that the Gaussian peaks were at the midpoint between the neighboring perturbers, The simulations showed an initial transient phase where the bulk of the primordial planetesimal swarm was removed from the Solar System within 10(5) years. This is about 10 times longer than we observed in our previous Jupiter/Saturn studies. Next, there was a gravitational relaxation phase where the particles underwent a random walk in momentum space and were exponentially eliminated by random encounters with the planets. Unlike our previous Jupiter/Saturn simulation, the particles did not fully relax into a third Lagrangian niche phase where long-lived particles are at Lagrange points or stable niches. This is either because the Lagrangian niche phase never occurs or because these simulations did not have enough particles for this third phase to manifest. In these simulations, there was a general trend for the particles to migrate outward and eventually to be cleared out by the outermost planet in the zone. We confirmed that particles with higher eccentricities had shorter lifetimes and that the resonances between the jovian planets "pumped up" the eccentricities of the planetesimals with low-inclination orbits more than those with higher inclinations. We estimated the expected lifetime of particles using kinetic theory and even though the time scale of the Uranus/Neptune simulation was 380 times longer than our previous Jupiter/Saturn simulation, the planetesimals in the Uranus/Neptune zone were cleared out more quickly than those in the Saturn/Uranus zone because of the positions of resonances with the jovian planets. These resonances had an even greater effect than random gravitational stirring in the winnowing process and confirm that all the jovian planets are necessary in long simulations. Even though we observed several long-lived zones near 12.5, 14.4, 16, 24.5, and 26 AU, only two particles remained at the end of the 10(9)-year integration: one near the 2:3 Saturn resonance, and the other near the Neptune 1:1 resonance. This suggests that niches for planetesimal material in the jovian planets are rare and may exist either only in extremely narrow bands or in the neighborhoods of the triangular Lagrange points of the outer planets. (C) 1999 Academic Press. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Math, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Grazier, KR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Newman, William/E-5918-2011 OI Newman, William/0000-0002-9835-1428 NR 34 TC 25 Z9 25 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD AUG PY 1999 VL 140 IS 2 BP 353 EP 368 DI 10.1006/icar.1999.6147 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 239EB UT WOS:000082754900008 ER PT J AU Park, SG Weiner, AM Melloch, MR Siders, CW Siders, JLW Taylor, AJ AF Park, SG Weiner, AM Melloch, MR Siders, CW Siders, JLW Taylor, AJ TI High-power narrow-band terahertz generation using large-aperture photoconductors SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE large-aperture; low-temperature-grown GaAs; photoconductor; saturation; terahertz ID MOLECULAR-BEAM EPITAXY; FIELD-DYNAMICS; ELECTROMAGNETIC PULSES; CARRIER LIFETIME; ANTENNAS; RADIATION; GAAS; SYSTEMS AB Large-aperture biased photoconductive emitters which can generate high-power narrow-band terahertz (THz) radiation are developed. These emitters avoid saturation at high fluence excitation and achieve enhanced peak power spectral density by employing a thick lager of short-lifetime low-temperature-grown GaAs (LT-GaAs) photoconductor and multiple-pulse excitation. THz waveforms are calculated from the saturation theory of large-aperture photoconductors, and a comparison is made between theory and measurement. A direct comparison of the multiple-pulse saturation properties of THz emission from semi-insulating GaAs and LT-GaAs emitters reveals a strong dependence on the carrier lifetime. In particular, the data demonstrate that saturation is avoided only when the interpulse spacing is longer than the carrier lifetime. C1 Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Park, SG (reprint author), AT&T Bell Labs, Res Labs, Red Bank, NJ 07701 USA. OI Park, Sang-Gyu/0000-0002-6051-0163 NR 27 TC 57 Z9 60 U1 2 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD AUG PY 1999 VL 35 IS 8 BP 1257 EP 1268 DI 10.1109/3.777228 PG 12 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 220WR UT WOS:000081691600020 ER PT J AU Tan, Q Schaible, B Bond, LJ Lee, YC AF Tan, Q Schaible, B Bond, LJ Lee, YC TI Thermosonic flip-chip bonding system with a self-planarization feature using polymer SO IEEE TRANSACTIONS ON ADVANCED PACKAGING LA English DT Article DE thermosonic; flip chip; ultrasonic; microelectronic packaging; wire bonding; finite element method AB Thermosonic flip-chip bonding is a wire bonding technology modified for flip-chip assembly. Compared with the soldering technology, it is simpler, faster and more cost-effective. Unfortunately, the yield of thermosonic bonding is low and unreliable because it is difficult to control the ultrasonic energy transmission. A small planarity angle between the bonding tool and stage can result in a nonuniform ultrasonic energy distribution. A self-planarization concept was proposed to solve this problem. A layer of polymer was placed between the bonding tool and the chip to smooth the nonplanar contact. Experimental measure-ments and finite element modeling were used to study the effect of the polymer layer. Results showed that the polymer layer could assure a uniform ultrasonic energy distribution; however, it also reduced the energy transmission efficiency. A case study for optimization was conducted based on finite element modeling. For a 1000-I/O hip chip assembly with a 250 mu m pitch using a bonder with a 0.010 planarity angle, polymer thickness of 350 mu m and a Young's modulus of 2 Gpa were selected. C1 Motorola Inc, Semicond Prod Sector, Austin, TX 78721 USA. Univ Colorado, Boulder, CO 80309 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Tan, Q (reprint author), Motorola Inc, Semicond Prod Sector, Austin, TX 78721 USA. NR 16 TC 18 Z9 22 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1521-3323 J9 IEEE TRANS ADV PACK JI IEEE Trans. Adv. Packag. PD AUG PY 1999 VL 22 IS 3 BP 468 EP 475 DI 10.1109/6040.784501 PG 8 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 230ZZ UT WOS:000082282700032 ER PT J AU Cuneo, ME AF Cuneo, ME TI The effect of electrode contamination, cleaning and conditioning on high-energy pulsed-power device performance SO IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION LA English DT Review ID FIELD ION DIODE; GLOW-DISCHARGE; ANODE PLASMA; SURFACE FLASHOVER; STAINLESS-STEEL; MICROWAVE GENERATION; RELTRON TUBES; BEAM DIODE; VACUUM; EMISSION AB High-energy pulsed-power devices routinely use field strengths above those at which broad-area, cathode-initiated, HV vacuum-breakdown occur (>10(7) to 3x10(7) V/m). Examples include magnetically-insulated transmission-lines and current convolutes, high-current-density electron and ion diodes, high-power microwave devices, and cavities and other structures far electrostatic and RF accelerators. Energy deposited in anode surfaces may exceed anode plasma thermal-desorption creation thresholds on the time scale of the pulse. Stimulated desorption by electron or photon bombardment also can lead to plasma formation on electrode or insulator surfaces. Device performance is limited above these thresholds, particularly in pulse length and energy, by the formation and expansion of neutral and plasma layers formed primarily from electrode contaminants. In-situ conditioning techniques to modify and eliminate the contaminants through multiple HV pulses, low base pressures, RF discharge cleaning, heating, surface coatings, and ion- and electron-beam surface treatment allow access to new regimes of performance through control of plasma formation and modification of the plasma properties. Experimental and theoretical progress from a variety of devices and small scale experiments with a variety of treatment methods will be reviewed and recommendations given for future work. C1 Sandia Natl Labs, Pulsed Power Sci Ctr, Albuquerque, NM 87185 USA. RP Cuneo, ME (reprint author), Sandia Natl Labs, Pulsed Power Sci Ctr, POB 5800, Albuquerque, NM 87185 USA. NR 145 TC 57 Z9 58 U1 0 U2 14 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1070-9878 EI 1558-4135 J9 IEEE T DIELECT EL IN JI IEEE Trns. Dielectr. Electr. Insul. PD AUG PY 1999 VL 6 IS 4 BP 469 EP 485 DI 10.1109/94.788747 PG 17 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 235LK UT WOS:000082543000017 ER PT J AU Dow, SF Karcher, A Levi, ME Momayezi, M von der Lippe, H Ando, D AF Dow, SF Karcher, A Levi, ME Momayezi, M von der Lippe, H Ando, D TI Design and performance of the Elefant Digitizer IC for the BaBar drift chamber SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB A 250,000 transistor full custom integrated circuit for the readout of drift chamber signals has been developed, produced and characterized. The "Elefant" (ELEctronics For Amplitude 'N Timing) Digitizer IC is designed to measure both the charge and the single electron time of arrival of sense wire signals from the BaBar drift chamber. By combining a FADC (Flash Analog-to-Digital Converter) and a TDC (Time-to-Digital Converter) for each channel, the digitizer IC can be optimized and simplified, to achieve the physics goals required of the drift chamber while reducing the per channel costs of the electronics. The Elefant IC also implements portions of the BaBar Trigger protocols to simplify the connection of the chip to the rest of the BaBar detector. Each IC contains eight complete independent channels. The circuit has been implemented in a 0.8 mu m triple metal CMOS process and fabricated in production quantity to fully instrument the BaBar Drift Chamber and are now in operation. Performance results of the IC will be presented. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Dow, SF (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 6 TC 11 Z9 11 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1999 VL 46 IS 4 BP 785 EP 791 DI 10.1109/23.790679 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 235WH UT WOS:000082565200001 ER PT J AU Einsweiler, K Joshi, A Marchesini, R Pengg, F Zizka, G AF Einsweiler, K Joshi, A Marchesini, R Pengg, F Zizka, G TI On the performance and limitations of a dual threshold discriminator pixel readout circuit for LHC SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB The analog front-end of pixel readout electronics with dual threshold discriminator scheme has been measured extensively to determine the optimum performance and performance Limitations of the circuit. The preamplifier shows a peaking time of 20ns without capacitive load, which degrades to only 30ns with a load of 350fF. The LEVEL-discriminator has an adjustable threshold in the range of 2000 to 6000e(-) with a variable separation to the TIME-discriminator threshold of 800 to 1600e(-), The circuit allows the full suppression of out-of-time signals under the conditions of 350fF capacitive load and a total power consumption of 40 mu W per cell. The untuned threshold dispersion is measured to be 320e(-) r.m.s., which reduces to 70e(-) r.m.s. after threshold adjust. The overall noise of the circuit reaches a value of about 200e(-) r.m.s. with 350fF capacitive load and 20nA of parallel current at the preamplifier input. Further measurements characterize the time-over-threshold (TOT) behaviour and the double-pulse resolution of the circuit. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Einsweiler, K (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 9 TC 4 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1999 VL 46 IS 4 BP 792 EP 799 DI 10.1109/23.790680 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 235WH UT WOS:000082565200002 ER PT J AU Pietraski, PJ Zojceski, Z Siddons, DP Smith, GC Yu, B AF Pietraski, PJ Zojceski, Z Siddons, DP Smith, GC Yu, B TI Digital centroid-finding electronics for high-rate detectors SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB Fast centroid-finding electronics are being developed for a range of position-sensitive gas proportional detectors. Each cathode strip feeds a preamplifier, shaper and a free-running ADC, Increased total count rate is achieved by dividing the detector into several segments with parallel processing that introduces no common dead time,Each segment has central-channel finding logic and event listing realized in a FPGA, followed by a DSP that performs the centroid calculation and histogramming. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Pietraski, PJ (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 11 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1999 VL 46 IS 4 BP 810 EP 816 DI 10.1109/23.790683 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 235WH UT WOS:000082565200005 ER PT J AU Borchi, E Bruzzi, M Dezillie, B Lazanu, S Li, Z Pirollo, S AF Borchi, E Bruzzi, M Dezillie, B Lazanu, S Li, Z Pirollo, S TI Hall effect analysis in irradiated silicon samples with different resistivities SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID DETECTORS; RADIATION; DEFECT AB The changes induced by neutron irradiation in n- and p-type silicon samples with starting resistivities from 10 Omega-cm up to 30 K Omega-cm, grown, using different techniques, as Float-Zone (FZ), Czochralski (CZ) and epitaxial, have been analyzed by Van der Pauw and Hall effect measurements. Increasing the fluence, each set of samples evolves toward a quasi-intrinsic p-type material. This behavior has been explained in the frame of a two-level model, that considers the introduction during irradiation of mainly two defects. A deep acceptor and a deep donor,probably related to the divacancy and to the CiOi complex, are placed in the upper and lower half of the forbidden gap, respectively. This simple model explains quantitatively the data on resistivity and Hall coefficient of each set of samples up to the fluence of approximate to 10(14) n/cm(2). C1 Ist Nazl Fis Nucl, I-50139 Florence, Italy. Dipartimento Energet Firenze, I-50139 Florence, Italy. Brookhaven Natl Lab, Upton, NY 11973 USA. Natl Inst Mat Phys, Bucharest 76900, Romania. RP Borchi, E (reprint author), Ist Nazl Fis Nucl, Via S Marta 3, I-50139 Florence, Italy. RI Lazanu, Sorina/B-7819-2012; Bruzzi, Mara/K-1326-2015 OI Lazanu, Sorina/0000-0003-0390-0779; Bruzzi, Mara/0000-0001-7344-8365 NR 12 TC 10 Z9 10 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1999 VL 46 IS 4 BP 834 EP 838 DI 10.1109/23.790687 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 235WH UT WOS:000082565200009 ER PT J AU Abramov, V Babintsev, V Baldin, B Butler, J Beutel, D Bezzubov, V Bojko, N Burtovoi, V Chekulaev, S Chi, E Denisov, D Denisov, S Diehl, T Dyshkant, A Eroshin, O Evdokimov, V Galyaev, A Goncharov, P Green, D Gurzhiev, S Haggerty, H Hanlet, P Hansen, S Hedin, D Ito, A Johns, K Kostritskiy, A Kozelov, A Kozlovski, E Leitner, R Lokajicek, M Los, S Mayorov, A Medovikov, V Mokhov, N Pospisil, S Raskowski, J Simak, V Smith, G Stefanik, A Stoianova, D Suk, M Vaniov, V Volkov, A Vorobiev, A Vrba, V Williams, R Wood, D Yoffe, F Zimin, S AF Abramov, V Babintsev, V Baldin, B Butler, J Beutel, D Bezzubov, V Bojko, N Burtovoi, V Chekulaev, S Chi, E Denisov, D Denisov, S Diehl, T Dyshkant, A Eroshin, O Evdokimov, V Galyaev, A Goncharov, P Green, D Gurzhiev, S Haggerty, H Hanlet, P Hansen, S Hedin, D Ito, A Johns, K Kostritskiy, A Kozelov, A Kozlovski, E Leitner, R Lokajicek, M Los, S Mayorov, A Medovikov, V Mokhov, N Pospisil, S Raskowski, J Simak, V Smith, G Stefanik, A Stoianova, D Suk, M Vaniov, V Volkov, A Vorobiev, A Vrba, V Williams, R Wood, D Yoffe, F Zimin, S TI Fast scintillation counters for the DO muon system upgrade SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB The design and main parameters of the completly redesigned DO Forward Angle MUon System (FAMUS: 1.0 < \eta\ < 2.0) for the next high luminosity Tevatron Collider run are reported. Results of the studies of trigger scintillation counters based on fast scintillator Bicron 404A and WLS bars SOFZ-105 are presented. We report about results of test beam studies of prototype counters including minimum ionizing particles detection efficiency, time resolution and amplitude response. Radiation ageing of scintillating materials for the doses up to 1 Mrad, phototubes magnetic shielding in the fields of up to 700 G and ageing of phototubes are presented. All tests show robustness of scintillation counters as triggering detector of the new muon system for a long period. C1 Inst High Energy Phys, Protvino, Russia. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Boston Univ, Boston, MA 02215 USA. No Illinois Univ, De Kalb, IL 60115 USA. Northeastern Univ, Boston, MA 02115 USA. Univ Arizona, Tucson, AZ USA. Charles Univ, Fac Math & Phys, Prague, Czech Republic. Acad Sci Czech Republ, Inst Phys, Prague, Czech Republic. Czech Tech Univ, Fac Nucl Sci & Phys Engn, CR-11519 Prague, Czech Republic. RP Abramov, V (reprint author), Inst High Energy Phys, Protvino, Russia. RI Kozelov, Alexander/J-3812-2014; Chekulaev, Sergey/O-1145-2015 NR 10 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1999 VL 46 IS 4 BP 865 EP 868 DI 10.1109/23.790693 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 235WH UT WOS:000082565200015 ER PT J AU Browne, MC Bowles, TJ Brice, SJ Doe, PJ Duba, CA Elliott, SR Esch, EI Fowler, MM Germani, JV Goldschmidt, A Heeger, KM Hime, A Lesko, KT Miller, CG Ollerhead, RW Poon, AWP Robertson, RGH Smith, MWE Steiger, TD Stokstad, RG Thornewell, PM Wilhelmy, JB Wilkerson, JF Wouters, JM AF Browne, MC Bowles, TJ Brice, SJ Doe, PJ Duba, CA Elliott, SR Esch, EI Fowler, MM Germani, JV Goldschmidt, A Heeger, KM Hime, A Lesko, KT Miller, CG Ollerhead, RW Poon, AWP Robertson, RGH Smith, MWE Steiger, TD Stokstad, RG Thornewell, PM Wilhelmy, JB Wilkerson, JF Wouters, JM TI Low-background He-3 proportional counters for use in the Sudbury Neutrino Observatory SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB Current solar neutrino detectors measure a considerably lower flux of electron-flavor neutrinos than predicted by solar models. This could be an indication of neutrino oscillations, which would provide direct evidence that neutrinos have mass. The Sudbury Neutrino Observatory (SNO) was designed to detect all flavors of neutrinos, and will provide a rigorous test of this theory. The SNO detector's heavy water target gives it the unique ability to detect all non-sterile neutrino flavors via the neutral-current (NC) break-up of the deuteron. This NC interaction liberates a neutron which may be detected with an array of discrete He-3 proportional counters. The strict radioactivity requirements imposed by the need for low backgrounds dictate the use of ultra-pure materials and processes in building these counters. Additionally, they must survive in the heavy water environment for several years. The design, construction, and testing of these unique counters are described. C1 Univ Washington, Nucl Phys Lab, Seattle, WA 98195 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. RP Browne, MC (reprint author), Univ Washington, Nucl Phys Lab, Seattle, WA 98195 USA. OI Wilkerson, John/0000-0002-0342-0217 NR 10 TC 11 Z9 11 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1999 VL 46 IS 4 BP 873 EP 876 DI 10.1109/23.790695 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 235WH UT WOS:000082565200017 ER PT J AU Ludewigt, BA Krieger, B Lindstrom, D Maier, MR Rutgersson, M Tull, CR Yaver, H AF Ludewigt, BA Krieger, B Lindstrom, D Maier, MR Rutgersson, M Tull, CR Yaver, H TI Silicon array detector system for high-rate, low-noise X-ray spectroscopy SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE ID PREAMPLIFIER-SHAPER AB A silicon array detector system is being developed for x-ray fluorescence applications at synchrotron light sources. The detector is wire-bonded to integrated circuits, which feature 32 channels of charge-sensitive preamplifiers followed by variable-gain pulse shaping amplifiers. The ICs directly drive CAMAC-based AID boards designed for this application. The data are transferred from the custom designed 16-channel ADC modules via FERABUS readout to commercially available histogramming modules and memory lookup units. The system features fully parallel signal processing to maintain high count-rate capability and to preserve the position information. Special LabVIEW-based software has been developed for data acquisition and analysis. The system, currently being assembled for 64 channels, can easily be expanded by increasing the number of detection channels and hardware modules. C1 Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Chalmers Univ Technol, S-41296 Gothenburg, Sweden. RP Ludewigt, BA (reprint author), Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 8 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1999 VL 46 IS 4 BP 886 EP 889 DI 10.1109/23.790698 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 235WH UT WOS:000082565200020 ER PT J AU Yaver, H Maier, MR Lindstrom, D Ludewigt, BA AF Yaver, H Maier, MR Lindstrom, D Ludewigt, BA TI Adaptive readout technique for a sixteen channel peak sensing ADC in the FERA format SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB An adaptive variable block size readout technique for use with multiple sixteen channel CAMAC ADCs with a FERA-bus readout has been developed and designed. It can be used to read data from experiments with or without coincidence, i.e. singles, without having to change the readout protocol. Details of the implementation are discussed and initial results are presented. Further applications of the adaptive readout are also discussed. C1 EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Chalmers Univ Technol, S-41296 Gothenburg, Sweden. RP Yaver, H (reprint author), EO Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1999 VL 46 IS 4 BP 924 EP 927 DI 10.1109/23.790705 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 235WH UT WOS:000082565200027 ER PT J AU Berenyi, A Chen, HK Dao, K Dow, SF Gehrig, SK Gill, MS Grace, C Jared, RC Johnson, JK Karcher, A Kasen, D Kirsten, FA Kral, JF LeClerc, CM Levi, ME von der Lippe, H Liu, TH Marks, KM Meyer, AB Minor, R Montgomery, AH Romosan, A AF Berenyi, A Chen, HK Dao, K Dow, SF Gehrig, SK Gill, MS Grace, C Jared, RC Johnson, JK Karcher, A Kasen, D Kirsten, FA Kral, JF LeClerc, CM Levi, ME von der Lippe, H Liu, TH Marks, KM Meyer, AB Minor, R Montgomery, AH Romosan, A TI A binary link tracker for the BaBar Level 1 trigger system SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB The BABAR detector at PEP-II will operate in a high-luminosity e(+)e(-) collider environment near the Y(4S) resonance with the primary goal of studying CP violation in the B meson system. In this environment, typical physics events of interest involve multiple charged particles. These events are identified by counting these tracks in a fast first level (Level 1) trigger system, by reconstructing the tracks in "real time." For this purpose, a Binary Link Tracker Module (BLTM) was designed and fabricated for the BABAR Level 1 Drift Chamber trigger system. The BLTM is responsible for linking track segments, constructed by the Track Segment Finder Modules (TSFM), into complete tracks. A single BLTM module processes a 360 MBytes/s: stream of segment hit data, corresponding to information from the entire Drift chamber, and implements a fast and robust algorithm that tolerates high hit occupancies as well as local inefficiencies of the Drift Chamber. The algorithms and the necessary control logic of the BLTM were implemented in Field Programmable Gate Arrays (FPGAs), using the VHDL hardware description language. The finished 9U x 400 nun Euro-format board contains roughly 75,000 gates of programmable logic or about 10,000 lines of VHDL code synthesized into five FPGAs. C1 EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Berenyi, A (reprint author), EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Montgomery, Alexander/B-4969-2009 OI Montgomery, Alexander/0000-0003-4166-0534 NR 6 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1999 VL 46 IS 4 BP 928 EP 932 DI 10.1109/23.790706 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 235WH UT WOS:000082565200028 ER PT J AU Ciobanu, C Gerstenslager, J Hoftiezer, J Hughes, R Johnson, M Koehn, P Neu, C Sanchez, C Winer, BL Freeman, J Holm, S Lewis, JD Shaw, T Wesson, T Bloom, K Gerdes, D Dawson, JW Haberichter, WN AF Ciobanu, C Gerstenslager, J Hoftiezer, J Hughes, R Johnson, M Koehn, P Neu, C Sanchez, C Winer, BL Freeman, J Holm, S Lewis, JD Shaw, T Wesson, T Bloom, K Gerdes, D Dawson, JW Haberichter, WN TI Online track processor for the CDF upgrade SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB A trigger track processor is being designed for the CDF upgrade. This processor identifies high momentum (P-T > 1.5 GeV/c) charged tracks in the new central outer tracking chamber for CDF II. The track processor is called the eXtremely Fast Tracker (XFT). The XFT design is highly parallel to handle the input rate of 183 Gbits/sec and output rate of 44 Gbits/sec. The processor is pipelined and reports the results for a new event every 132 ns. The processor uses three stages, hit classification, segment finding, and segment linking. The pattern recognition algorithms for the three stages are implemented in programmable logic devices (PLDs) which allow for in-situ modification of the algorithm at any time. The PLDs reside on three different types of modules. Prototypes of each of these modules have been designed and built, and are presently undergoing testing. An overview of the track processor and results of testing are presented. C1 Ohio State Univ, Columbus, OH 43210 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Ciobanu, C (reprint author), Ohio State Univ, Columbus, OH 43210 USA. NR 3 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1999 VL 46 IS 4 BP 933 EP 939 DI 10.1109/23.790707 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 235WH UT WOS:000082565200029 ER PT J AU Holslin, D Foster, L Verbinski, V AF Holslin, D Foster, L Verbinski, V TI A moisture probe using neutron moderation for PuO2 canister inspection SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Nuclear Science Symposium (NSS) CY NOV 08-14, 1998 CL TORONTO, CANADA SP IEEE AB We have been developing a sensor to quickly and nondestructively measure the moisture content of canisters containing PuO2. These canisters will be retained in longterm storage facilities and, for stability reasons, must have moisture contents <0.5 wt%. The technique relies on the moderation of neutrons emitted by a radioisotopic source (Cf-252) to determine the hydrogen content of the material. Modeling was used to help optimize the sensor design and to predict the sensitivity to moisture content. A benchmodel was first constructed and tested at SAIC with simulated PuO2 using Fe3O4 and B4C; moisture was simulated with nylon rods. The benchmodel was also tested at Los Alamos National Laboratory (LANL) using actual PuO2-filled canisters modified to accept polyethylene rods to simulate moisture. The results indicated that the detection limit tone statistical standard deviation) for a 10 minute inspection was less than 1.2 g of water, or 0.04wt%, in 3 kg of PuO2. A prototype system was recently constructed for testing a variety of PuO2 samples with various material matrices. Here we present the calculations, sensor designs, tests, test results, and discuss future plans. C1 Sci Applicat Int Corp, San Diego, CA 92127 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Holslin, D (reprint author), Sci Applicat Int Corp, 16701 W Bernardo Dr, San Diego, CA 92127 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 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1999 VL 46 IS 4 BP 953 EP 956 DI 10.1109/23.790710 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 235WH UT WOS:000082565200032 ER PT J AU Gleason, SS Sari-Sarraf, H Paulus, MJ Johnson, DK Norton, SJ Abidi, MA AF Gleason, SS Sari-Sarraf, H Paulus, MJ Johnson, DK Norton, SJ Abidi, MA TI Reconstruction of multi-energy x-ray computed tomography images of laboratory mice SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1998 Medical Imaging Conference CY NOV 12-14, 1998 CL TORONTO, CANADA AB A new x-ray computed tomography (CT) system is being developed at Oak Ridge National Laboratory to image laboratory mice for the purpose of rapid phenotype screening and identification. One implementation of this CT system allows simultaneous capture of several sets of sinogram data, each having a unique x-ray energy distribution. The goals of this paper are to (1) identify issues associated with the reconstruction of this energy-dependent data and (2) suggest preliminary approaches to address these issues. Due to varying numbers of photon counts within each set, both traditional (filtered backprojection, or FBP) and statistical (maximum likelihood, or ML) tomographic image reconstruction techniques have been applied to the energy-dependent sinogram data. Results of reconstructed images using both algorithms on sinogram data (high- and low-count) are presented. Also, tissue contrast within the energy-dependent images is compared to known x-ray attenuation coefficients of soft tissue (e.g. muscle, bone, and fat). C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Elect Engn, Knoxville, TN 37996 USA. RP Gleason, SS (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 12 TC 31 Z9 31 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD AUG PY 1999 VL 46 IS 4 BP 1081 EP 1086 DI 10.1109/23.790832 PN 2 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 235WN UT WOS:000082566000018 ER PT J AU Beilis, II Keidar, M Boxman, RL Goldsmith, S AF Beilis, II Keidar, M Boxman, RL Goldsmith, S TI Plasma expansion and current flow in a vacuum arc with a small anode SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article; Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL DE anode sheath; anode voltage; arc current compression; free boundary; plasma expansion; plasma flow compression; small anode; vacuum arc plasma jet ID MAGNETIC-FIELD; PARAMETERS; DISCHARGE; JET AB act--A low-density plasma dow in a vacuum are with a small anode, which intercepts only part of the cathodic plasma jet, was studied theoretically using a two-dimensional approximation. The plasma expansion was modeled using the sourceless steady-state hydrodynamic equations, where the free boundary of the plasma was determined by a self-consistent solution of the gasdynamic and electrical current equations. Magnetic forces from the azimuthal self-magnetic field were taken into account. The influence of the ratio of the anode radius to initial plasma jet radius on the plasma density, velocity, current distribution, and anode sheath potential drop is analyzed. It is shown that the mass and current flow in a 500 A are are compressed near the axis. This leads to an increase in the plasma density by a factor of two and in the axial current density by a factor of 1.5. C1 Tel Aviv Univ, Elect Discharge & Plasma Lab, IL-69978 Tel Aviv, Israel. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Beilis, II (reprint author), Tel Aviv Univ, Elect Discharge & Plasma Lab, IL-69978 Tel Aviv, Israel. NR 11 TC 7 Z9 7 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD AUG PY 1999 VL 27 IS 4 BP 872 EP 876 DI 10.1109/27.782252 PG 5 WC Physics, Fluids & Plasmas SC Physics GA 227DX UT WOS:000082064000010 ER PT J AU Schulke, T Anders, A AF Schulke, T Anders, A TI Ion charge state distributions of alloy-cathode vacuum arc plasmas SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article; Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL AB Ion charge state distributions (CSD's) of alloy-cathode vacuum are plasmas have been calculated under the assumption that thermodynamic equilibrium is valid in the vicinity of the cathode spot, and equilibrium CSD's "freeze" when the plasma is rapidly expanding. In this way, experimental data of titanium-hafnium alloy-cathode plasmas have been simulated using a system of Saha equations generalized for multiple elements. It was found that the CSD's of titanium and hafnium freeze approximately at the same plasma temperature and density, The freezing parameters depend slightly on the plasma composition. For the example considered, freezing occurs at temperature of T = 3.0-3.8 eV and a total heavy particle density of order 10(25) m(-3). C1 Fraunhofer Resource Ctr Michigan, Ann Arbor, MI 48105 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Fraunhofer Resource Ctr Michigan, Ann Arbor, MI 48105 USA. EM aanders@lbl.gov RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 13 TC 12 Z9 13 U1 1 U2 2 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 AUG PY 1999 VL 27 IS 4 BP 911 EP 914 DI 10.1109/27.782259 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 227DX UT WOS:000082064000017 ER PT J AU Monteiro, OR Anders, A AF Monteiro, OR Anders, A TI Vacuum-arc-generated macroparticles in the nanometer range SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article; Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL ID DEPOSITION; TRANSPORT AB Micron and submicron "macroparticles" are produced along with the plasma at vacuum are cathode spots. Published data refer to the sim range 0.2-100 mu m The lower limit is determined by the resolution of the equipment used (usually scanning electron microscopes). In the present study we focus on the detection and characterization of nanosize macroparticles ("nanoparticles") using atomic force microscopy and field-emission scanning electron microscopy, New information is gathered on material-dependent size distribution functions as well as on the effectiveness of magnetic filtering for nanoparticles. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Monteiro, OR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 14 TC 13 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 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD AUG PY 1999 VL 27 IS 4 BP 1030 EP 1033 DI 10.1109/27.782276 PG 4 WC Physics, Fluids & Plasmas SC Physics GA 227DX UT WOS:000082064000034 ER PT J AU Anders, A AF Anders, A TI Plasma fluctuations, local partial Saha equilibrium, and the broadening of vacuum-arc ion charge state distributions SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article; Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL ID MAGNETIC-FIELD; ALLOY CATHODES; PULSE; BEAMS AB Charge state distributions (CSD's) of Fe, Co, Zr, Nh, Hf, Ag, Pt, Au ions produced at vacuum are cathode spots are investigated without often-used averaging procedures. Statistical results are used to evaluate the contribution of fluctuations to the broadening of averaged CSD's, Calculations of Saha equations in the Debye-Huckel approximation are often successful in replicating experimental CSD's even when using the simple model of "instantaneous freezing." This allows us to use charge state spectrometry as a plasma diagnostic tool for the dense plasma near tbe cathode spot. Typically, total heavy particle (atoms and ions) densities and electron temperatures of 10(24)-10(25) m(-3) and 3-4 eV have been measured this way at the transition zone from equilibrium to nonequilibrium, the "event horizon." It was also found that CSD's for some elements such as Co, Ag, and Hf could not be accurately simulated with the assumption of instantaneous freezing. Here, a more gradual transition to nonequilibrium occurs. This transition can be described by the model of partial local Saha equilibrium. Finally, an axial magnetic field was found to soften the transition to nonequilibrium thus causing broadening of experimental CSD's. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM aanders@lbl.gov RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 33 TC 24 Z9 24 U1 0 U2 1 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 AUG PY 1999 VL 27 IS 4 BP 1060 EP 1067 DI 10.1109/27.782282 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 227DX UT WOS:000082064000040 ER PT J AU Goncharov, AA Gubarev, SM Dobrovolskii, AN Protsenko, IM Litovko, IV Brown, IG AF Goncharov, AA Gubarev, SM Dobrovolskii, AN Protsenko, IM Litovko, IV Brown, IG TI Moderate energy metal ion beam focusing by a high-current plasma lens SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article; Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL DE high current; ion beams; ion focusing; ion optics; plasma lens AB Some features of the electrostatic plasma lens as applied to the focusing of moderate-energy, high-current, wide-aperture metal ion beams have been investigated and are described here. Static characteristics within the plasma lens volume have been explored, It is shown that when the potentials applied to the lens electrodes are held constant, the electric field increase with increasing ion beam current is limited by the increase of the potential in the paraxial region of the beam. Some estimates are made of the limiting static electric fields that can be obtained in the plasma lens, based on a quasi-neutral, two-component plasma model with anomalous electron mobility, where it is assumed that the anomalous mobility is caused by the absence of electron correlations when vortex-like structures appear in the hydrodynamically unstable plasma. The results of a theoretical analysis are compared with experimental data. Some results of experiments on the focusing of high-current, large-area, heavy metal ion beams are also presented. C1 NASU, Inst Phys, UA-252650 Kiev, Ukraine. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Goncharov, AA (reprint author), NASU, Inst Phys, UA-252650 Kiev, Ukraine. RI Dobrovol`s`kii, Andrii/C-7626-2015 OI Dobrovol`s`kii, Andrii/0000-0001-9917-522X NR 6 TC 6 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 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD AUG PY 1999 VL 27 IS 4 BP 1068 EP 1072 DI 10.1109/27.782283 PG 5 WC Physics, Fluids & Plasmas SC Physics GA 227DX UT WOS:000082064000041 ER PT J AU Verhoeven, TGA Bongers, WA Bratman, VL Caplan, M Denisov, GG van der Geer, CAJ Manintveld, P Poelman, AJ Plomp, J Savilov, AV Smeets, PHM Sterk, AB Urbanus, WH AF Verhoeven, TGA Bongers, WA Bratman, VL Caplan, M Denisov, GG van der Geer, CAJ Manintveld, P Poelman, AJ Plomp, J Savilov, AV Smeets, PHM Sterk, AB Urbanus, WH TI First mm-wave generation in the FOM free electron maser SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article; Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL DE free electron lasers; masers; microwave generation; microwave power transmission; microwave tubes; millimeter wave generation; millimeter wave tubes ID FEM OSCILLATOR; SIMULATIONS; FUSION; PERFORMANCE; GHZ AB A free electron maser (FEM) has been built as a pilot mm-wave source for applications on future fusion research devices such as international tokamak experimental reactor (ITER), A unique feature of the Dutch FEM is the possibility to tune the frequency over the entire range from 130 to 260 GHz at an output power exceeding one MW, In the first phase of the project, the so-called inverse setup is used, where the electron gun is mounted inside the high-voltage terminal. The entire beam line was tested successfully with an extremely low loss current, lower than 0.05 %, First generation of mm waves was achieved in October 1997, Up to now a peak power exceeding 730 kW was measured at 200 GHz and 350 kW at 167 GNz, Output power, start-up time and frequency correspond well with simulation results, Parameter scans for the longitudinal undulator gap, accelerator voltage, and reflection coefficient have given a wide range of interesting data of which a few highlights are given. C1 EURATOM, FOM, Inst Plasmafys Rijnhuizen, NL-3430 BE Nieuwegein, Netherlands. Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603600, Russia. Lawrence Livermore Natl Labs, Livermore, CA 94551 USA. RP Verhoeven, TGA (reprint author), EURATOM, FOM, Inst Plasmafys Rijnhuizen, NL-3430 BE Nieuwegein, Netherlands. NR 13 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 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD AUG PY 1999 VL 27 IS 4 BP 1084 EP 1091 DI 10.1109/27.782286 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 227DX UT WOS:000082064000044 ER PT J AU Bradley, JT Gahl, JM Rockett, PD AF Bradley, JT Gahl, JM Rockett, PD TI Diagnostics and analysis of incident and vapor shield plasmas in PLADIS I, a coaxial deflagration gun for tokamak disruption simulation SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article; Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL DE ablation; cooperative tokamak disruption simulation experiments; dense vapor shield; disruption-like heat flux; energy fluxes; graphite erosion; graphites; heat load material; impurity content; ITER program; PLADIS plasma gun simulator; plasma diagnostics; plasma facing components; plasma facing component materials; plasma flow; plasma stream impact; plasma wall interactions; tokamak disruption; tokamak disruption simulation experiments; tokamak disruption simulations; transmission grating; vacuum ultraviolet spectrographs ID HEAT LOAD MATERIAL AB Tokamak disruption simulation experiments have been conducted at the University of New Mexico using the PLADIS I plasma gun system. Earlier work had characterized the plasma-surface interaction in terms of parameters such as incident energy from bucket calorimeter measurements and rough measurements of beam area from flat damage targets. A variety of new plasma diagnostics have been used to further investigate the characteristics of the incident plasma beam and vapor shield plasma in a simulated tokamak disruption. These diagnostics have included laser interferometry, two-color pyrometry, emission spectroscopy, and other methods to quantify the characteristics of the incident and vapor shield plasmas of a simulated tokamak disruption. The synthesis of different beam area measurement techniques is used to determine the radial structure of the plasma beam. Vacuum ultra violet spectroscopy is used to determine the thickness and internal structure of the vapor shield plasma. Results from two-color optical pyrometry and surface pressure measurements are used to determine the dynamics of vapor shield formation. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ New Mexico, Dept Elect & Comp Engn, Albuquerque, NM 87131 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Bradley, JT (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 25 TC 6 Z9 6 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD AUG PY 1999 VL 27 IS 4 BP 1105 EP 1114 DI 10.1109/27.782290 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 227DX UT WOS:000082064000048 ER PT J AU Bilek, MMM Anders, A Brown, IG AF Bilek, MMM Anders, A Brown, IG TI Characterization of a linear venetian-blind macroparticle filter for cathodic vacuum arcs SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article; Proceedings Paper CT XVIIIth International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) CY AUG 17-21, 1998 CL EINDHOVEN UNIV TECHNOL, EINDHOVEN, NETHERLANDS SP ABB Calor Emag Schaltanlagen AG, Eindhoven Univ Technol, HOLEC Middenspanning BV, IEEE Dielectr & Elect Insulat Soc, KEMA T&D Power, Netherlands Vacuum Soc, PHILIPS Analyt X Ray, Sandia Natl Lab, SIEMENS Energieubertrag & Energieverteil AG, TOSHIBA HO EINDHOVEN UNIV TECHNOL DE coatings; plasma arc devices; plasmas; vacuum arcs ID DEPOSITION; TRANSPORT; PLASMAS; ION AB The cathodic vacuum are is a simple means of creating a highly ionized metal or carbon plasma, which can be used to produce a wide variety of metal and metal compound thin films. In order to produce smooth, defect-free films suitable for optical and electronic applications, the plasma needs to be filtered of micrometer-sized molten and solid cathode debris known as macroparticles, To date, most of the research effort on plasma filtering has been focused on development and optimization of magnetic filter designs based on curved solenoids, Ryabchikov et al, proposed and employed novel filter designs for a combined plasma and ion beam source. The new designs are based on a nested set of conical plates in one version and a set of angled plates ("venetian blind") in another. In the present work, we report on a detailed characterization of the operation of a filter employing a linear venetian blind geometry. The effects of parameters such as plate and are currents, as well as plate bias on the throughput and deposition profile are reported. C1 Univ Cambridge, Dept Engn, Cambridge CB2 1PZ, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Bilek, MMM (reprint author), Univ Cambridge, Dept Engn, Cambridge CB2 1PZ, England. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 12 TC 17 Z9 17 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-3813 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD AUG PY 1999 VL 27 IS 4 BP 1197 EP 1202 DI 10.1109/27.782300 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 227DX UT WOS:000082064000058 ER PT J AU Hauer, JF AF Hauer, JF TI Model validation for the August 10, 1996 WSCC system outage - Discussion SO IEEE TRANSACTIONS ON POWER SYSTEMS LA English DT Editorial Material C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Hauer, JF (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 4 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 USA SN 0885-8950 J9 IEEE T POWER SYST JI IEEE Trans. Power Syst. PD AUG PY 1999 VL 14 IS 3 BP 976 EP 977 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA 221FF UT WOS:000081712900045 ER PT J AU Hauer, JF Trudnowski, DJ AF Hauer, JF Trudnowski, DJ TI Performance comparison of three identification methods for the analysis of electromechanical oscillations - Discussion SO IEEE TRANSACTIONS ON POWER SYSTEMS LA English DT Editorial Material ID MODELS; ORDER C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Montana Tech, Butte, MT 59701 USA. RP Hauer, JF (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 12 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 USA SN 0885-8950 J9 IEEE T POWER SYST JI IEEE Trans. Power Syst. PD AUG PY 1999 VL 14 IS 3 BP 1002 EP 1002 PG 1 WC Engineering, Electrical & Electronic SC Engineering GA 221FF UT WOS:000081712900055 ER PT J AU Grigg, C Wong, P Albrecht, P Allan, R Bhavaraju, M Billinton, R Chen, Q Fong, C Haddad, S Kuruganty, S Li, W Mukerji, R Patton, D Rau, N Reppen, D Schneider, A Shahidehpour, M Singh, C AF Grigg, C Wong, P Albrecht, P Allan, R Bhavaraju, M Billinton, R Chen, Q Fong, C Haddad, S Kuruganty, S Li, W Mukerji, R Patton, D Rau, N Reppen, D Schneider, A Shahidehpour, M Singh, C CA Reliability Test System Task Force TI The IEEE reliability test system - 1996 SO IEEE TRANSACTIONS ON POWER SYSTEMS LA English DT Article; Proceedings Paper CT 1996 IEEE / PES Winter Meeting CY JAN 21-25, 1996 CL BALTIMORE, MARYLAND SP IEEE, PES AB This report describes an enhanced test system (RTS-96) for use in bulk power system reliability evaluation studies. The value of the test system Is that ie will permit comparative and benchmark studies to be performed on new and existing reliability evaluation techniques. The test system was developed by modifying and updating the original IEEE RTS (referred to as RTS-79 hereafter) to reflect changes in evaluation methodologies and to overcame perceived deficiencies. C1 Rose Hulman Inst Technol, Terre Haute, IN 47803 USA. NEPEX, Operat Planning & Procedures, Holyoke, MA USA. GE, Schenectady, NY 12301 USA. UMIST, Manchester M60 1QD, Lancs, England. Publ Serv Elect & Gas Co, Long Range Resource Planning, Newark, NJ 07101 USA. Univ Saskatchewan, Saskatoon, SK, Canada. NEPLAN, Power Supply Planning, Holyoke, MA USA. Ontario Hydro, Operat, Toronto, ON, Canada. Sargent & Lundy, Elect Anal Div, Chicago, IL USA. Univ N Dakota, Grand Forks, ND 58201 USA. BC Hydro, Analyt Studies, Vancouver, BC, Canada. Texas A&M Univ, Dept Elect Engn, College Stn, TX 77843 USA. NREL, Golden, CO USA. Power Technol Inc, Reliabil & Secur, Schenectady, NY 12301 USA. MAIN Coordinat Ctr, Lombard, IL USA. IIT, Chicago, IL 60616 USA. RP Grigg, C (reprint author), Rose Hulman Inst Technol, Terre Haute, IN 47803 USA. NR 5 TC 772 Z9 842 U1 6 U2 35 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-8950 J9 IEEE T POWER SYST JI IEEE Trans. Power Syst. PD AUG PY 1999 VL 14 IS 3 BP 1010 EP 1018 DI 10.1109/59.780914 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA 221FF UT WOS:000081712900058 ER PT J AU Li, SG Jin, WQ Huang, P Xu, NP Shi, J Lin, YS Hu, MZC Payzant, EA AF Li, SG Jin, WQ Huang, P Xu, NP Shi, J Lin, YS Hu, MZC Payzant, EA TI Comparison of oxygen permeability and stability of perovskite type La(0.2)A(0.8)Co(0.2)Fe(0.8)O(3-delta) (A = Sr, Ba, Ca) membranes SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID PARTIAL OXIDATION; CERAMIC MEMBRANES; DENSE PEROVSKITE; PERMEATION FLUX; METHANE; REACTORS; SYNGAS; TRANSPORT; OXIDES AB The oxygen permeation and stability of La(0.2)A(0.8)Co(0.2)Fe(0.8)O(3-delta) (A = Sr, Ba, Ca) perovskite-type membranes were studied at high temperatures and low oxygen partial pressures. The oxygen vacancy diffusivity and concentration gradient calculated from the unsteady-state and steady-state oxygen data for the three membranes decrease in the order of Sr > Ba > Ca. The activation energies for oxygen permeation increase in the order of Sr < Ba < Ca. The oxygen permeation data of the three membranes can be explained by the average bond energy, free volume, and critical radius of the materials. After exposure to air at 1173 K for 10 h, part of La0.2Sr0.8Co0.2Fe0.8O3-delta transforms to La2O3, SrO, CoO, and Fe and the crystallite size of the perovskite phase decreases. These changes were not observed for La0.2Ba0.8Co0.2Fe0.8O3-delta under the same conditions, indicating that La0.2Ba0.8Co0.2Fe0.8O3-delta membrane is much more stable than La0.2Sr0.8Co0.2Fe0.8O3-delta at high temperatures and low oxygen partial pressures. C1 Nanjing Inst Chem Technol, Membrane Sci & Technol Res Ctr, Nanjing 210009, Peoples R China. Univ Cincinnati, Dept Chem Engn, Cincinnati, OH 45221 USA. Oak Ridge Natl Lab, Div Met & Ceram, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Xu, NP (reprint author), Nanjing Inst Chem Technol, Membrane Sci & Technol Res Ctr, Nanjing 210009, Peoples R China. RI Payzant, Edward/B-5449-2009; Lin, Jerry/F-1235-2010; Jin, Wanqin/L-6011-2013 OI Payzant, Edward/0000-0002-3447-2060; Lin, Jerry/0000-0001-5905-8336; NR 41 TC 61 Z9 62 U1 0 U2 26 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD AUG PY 1999 VL 38 IS 8 BP 2963 EP 2972 DI 10.1021/ie9900014 PG 10 WC Engineering, Chemical SC Engineering GA 224CF UT WOS:000081878400013 ER PT J AU Neal, TJ Cheng, BS Ma, JG Shelnutt, JA Schulz, CE Scheidt, WR AF Neal, TJ Cheng, BS Ma, JG Shelnutt, JA Schulz, CE Scheidt, WR TI Conformational diversity in (octaethylporphinato)(trichloroacetato)iron(III) derivatives SO INORGANICA CHIMICA ACTA LA English DT Article DE crystal structures; iron complexes; porphyrin complexes ID NONPLANAR HEME DISTORTIONS; CRYSTAL-STRUCTURE; SPIN-STATE; MOLECULAR STEREOCHEMISTRY; PORPHYRINS; MACROCYCLE; HEMOPROTEINS; PERCHLORATE; COMPLEXES; PROTEIN AB Treatment of [Fe(OEP)](2)O with trichloroacetic acid (2.5-fold excess) results in the formation of (octaethylporphinato)(trichloroacetato)iron(III). Various crystalline solvates can be isolated, depending on the crystallization solvent. Initial crystallization with CHCl3/hexanes resulted in the isolation of a monoclinic (P2(1)/n, Z = 4) unsolvated form, [Fe(OEP)(O2C2Cl3)]. This form contains two distinct porphyrin core conformations at the same lattice site; one is domed and the other is ruffled. Subsequent crystallizations with CHCl3/hexanes resulted in a new triclinic (P (1) over bar, Z=2) crystalline form, [Fe(OEP)(O2C2CL2)]. CHCl3; the porphyrin core is slightly ruffled. Crystallization with CH,Cl,/hexanes resulted in the isolation of yet another form (triclinic, P (1) over bar, Z = 4), [Fe(OEP)(O2C2Cl3)]. HO2C2Cl3, which contains two independent molecules in the unit cell; molecule A is modestly ruffled and molecule B is slightly saddled. All conformations form pi--pi: dimers in the solid state. Temperature-dependent magnetic susceptibility measurements showed that [Fe(OEP)(O2C2Cl3)]. CHCl3 contains a high-spin iron(III) center; the data for [Fe(OEP)(O2C2Cl3)]. HO2C2Cl3 are understood in terms of an admired intermediate-spin state (S = 3/2, 5/2) and are readily fit to a Maltempo model with a ground state multiplet containing about 78% S = 5/2 character and 22% S = 3/2 character. The structural data for [Fe(OEP)(O2C2Cl3)]. CHCl3 are consistent with the observed high-spin state, while data for [Fe(OEP)(O2C2Cl3)]. HO2C2Cl3 are consistent with the admired-spin iron(III) character. The observed core conformations have been described by a normal-coordinate structural decomposition method. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Univ Notre Dame, Dept Chem & Biochem, Notre Dame, IN 46556 USA. Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. Sandia Natl Labs, Mat Theory & Computat Dept, Albuquerque, NM 87185 USA. Knox Coll, Dept Phys, Galesburg, IL 61401 USA. RP Scheidt, WR (reprint author), Univ Notre Dame, Dept Chem & Biochem, 251 Nieuwland Sci Hall, Notre Dame, IN 46556 USA. RI Shelnutt, John/A-9987-2009 OI Shelnutt, John/0000-0001-7368-582X NR 38 TC 9 Z9 9 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD AUG PY 1999 VL 291 IS 1-2 BP 49 EP 59 DI 10.1016/S0020-1693(99)00025-0 PG 11 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 227XG UT WOS:000082104800005 ER PT J AU Yang, ZJ Hull, JR AF Yang, ZJ Hull, JR TI Magnetic fields of cylindrical coils SO INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS LA English DT Article DE magnetic field; magnetic force; magnetic bearing AB Using mathematical transforms, we present an improved method to compute magnetic fields from current coils with cylindrical symmetry. For some typical model systems, the closed-forms are given for the convenience of use in engineering design. The method we present can generally be used to calculate magnetic field distributions for practical engineering designs with greater efficiency than conventional methods. This method can potentially be applied to other physical problems, such as deriving gravitational potential. C1 Argonne Natl Lab, Argonne, IL 60439 USA. NR 8 TC 5 Z9 6 U1 0 U2 1 PU IOS PRESS PI AMSTERDAM PA VAN DIEMENSTRAAT 94, 1013 CN AMSTERDAM, NETHERLANDS SN 1383-5416 J9 INT J APPL ELECTROM JI Int. J. Appl. Electromagn. Mech. PD AUG PY 1999 VL 10 IS 4 BP 351 EP 367 PG 17 WC Engineering, Electrical & Electronic; Mechanics; Physics, Applied SC Engineering; Mechanics; Physics GA 220WY UT WOS:000081692300006 ER PT J AU Chang, SJ AF Chang, SJ TI Near threshold fatigue curve based on the dislocation free zone model of fracture SO INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE LA English DT Article DE near threshold fatigue curve; dislocation free zone; fracture ID SCREW DISLOCATIONS; INCLINED PILEUP; CRACK TIP AB Dislocation pileup along an inclined direction from a crack tip has been observed in metals during tensile deformation in an electron microscope. Dislocations are emitted from the crack tip, move through a dislocation free zone, and pile up in the plastic zone. The problem of inclined pileup of screw dislocations at a crack tip with a dislocation free zone has been solved by applying the Wiener-Hopf method. The result can be used to calculate the crack tip blunting and the local stress intensity K for the applied stress intensity K-3. According to the fatigue theory of Laird or Neumann, the crack propagation per cycle has the order of magnitude of the blunting. The blunting versus K-3 is then plotted. It has the shape of the near threshold fatigue curve. To plot this curve, the local stress intensity K has been assumed to be the critical value K-g for the dislocation emission at the crack tip. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Res Reactors Div, Oak Ridge, TN 37831 USA. RP Chang, SJ (reprint author), Oak Ridge Natl Lab, Res Reactors Div, Oak Ridge, TN 37831 USA. NR 22 TC 2 Z9 3 U1 2 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7225 J9 INT J ENG SCI JI Int. J. Eng. Sci. PD AUG PY 1999 VL 37 IS 10 BP 1289 EP 1298 DI 10.1016/S0020-7225(98)00124-4 PG 10 WC Engineering, Multidisciplinary SC Engineering GA 205DF UT WOS:000080805500004 ER PT J AU Steinberg, M AF Steinberg, M TI Fossil fuel decarbonization technology for mitigating global warming SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article AB It has been understood that production of hydrogen from fossil and carbonaceous fuels with reduced CO2 emission to the atmosphere is key to the production of hydrogen-rich fuels for mitigating the CO2 greenhouse gas climate change problem. The conventional methods of hydrogen production from fossil fuels (coal, oil, gas and biomass) include steam reforming and water gas shift mainly of natural gas (SRM). In order to suppress CO2 emission from the steam reforming process, CO2 must be concentrated and sequestered either in or under the ocean or in or underground tin aquifers, or depleted oil or gas wells). Up to about 40% of the energy is lost in this process. An alternative process is the pyrolysis or the thermal decomposition of methane, natural gas (TDM) to hydrogen and carbon. The carbon can either be sequestered or sold on the market as a materials commodity or used as a fuel at a later date under less severe CO2 restraints. The energy sequestered in the carbon amounts to about 42% of the energy in the natural gas resource which is stored and not destroyed. A comparison is made between the well developed conventional SRM and the less developed TDM process including technological status, efficiency, carbon management and cost. The TDM process appears to have advantages over the well developed SRM process. It is much easier to sequester carbon as a stable solid than CO2 as a reactive gas or low temperature liquid. It is also possible to reduce cost by marketing the carbon as a filler or construction material, The potential benefits of the TDM process justifies its further efficient development. The hydrogen can be used as a transportation fuel or converted to methanol by reaction with CO2 from fossil fuel fired power plant stack gases, thus allowing reuse of the carbon in conventional IC automobile engines or in advanced fuel cell vehicles. (C) 1999 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Steinberg, M (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 15 TC 152 Z9 155 U1 5 U2 31 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3199 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD AUG PY 1999 VL 24 IS 8 BP 771 EP 777 DI 10.1016/S0360-3199(98)00128-1 PG 7 WC Chemistry, Physical; Electrochemistry; Energy & Fuels SC Chemistry; Electrochemistry; Energy & Fuels GA 224CM UT WOS:000081879200009 ER PT J AU Malov, DE Umar, AS Ernst, DJ Dean, DJ AF Malov, DE Umar, AS Ernst, DJ Dean, DJ TI Particle identification in the dynamical string-parton model of relativistic heavy-ion collisions SO INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS LA English DT Article ID LUND MONTE-CARLO; FLUX-TUBE; NUCLEAR COLLISIONS; JET FRAGMENTATION; PHYSICS; QUARK AB The dynamical string-parton model for relativistic heavy-ion collisions is generalized to include particle identification of the final-state hadrons by phenomenologically quantizing the masses of the classical strings which result from string breaking. General features of the Nambu-Goto strings are used to motivate a model that identifies a mass window near the physical mass of a meson, and does not allow the string to decay further if its mass falls within the window. Data from e(+)e(-) collisions in the region root s = 10 to 30 GeV are well reproduced by this model. C1 Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. RI Umar, Ahmet/J-4125-2013; OI Umar, Ahmet/0000-0002-9267-5253; Dean, David/0000-0002-5688-703X NR 30 TC 2 Z9 2 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-3013 EI 1793-6608 J9 INT J MOD PHYS E JI Int. J. Mod. Phys. E-Nucl. Phys. PD AUG PY 1999 VL 8 IS 4 BP 299 EP 309 DI 10.1142/S0218301399000215 PG 11 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 244ZN UT WOS:000083080800001 ER PT J AU Borcea, L Berryman, JG Papanicolaou, GC AF Borcea, L Berryman, JG Papanicolaou, GC TI Matching pursuit for imaging high-contrast conductivity SO INVERSE PROBLEMS LA English DT Article ID ELECTRICAL-IMPEDANCE TOMOGRAPHY; VARIATIONAL CONSTRAINTS; INVERSE PROBLEMS; NUMERICAL-METHOD; POSED PROBLEMS; L-CURVE; UNIQUENESS; STABILITY AB We show that imaging an isotropic, high contrast, conductive medium is asymptotically equivalent to the identification of a unique resistor network, given measurements of currents and voltages at the boundary. We show that a matching pursuit approach can be used effectively towards the numerical solution of the high-contrast imaging problem, if the library of functions is constructed carefully and in accordance with the asymptotic theory. We also show how other libraries of functions that at first glance seem reasonable, in fact, do not work well. When the contrast in the conductivity is not so high, we show that wavelets can be used, especially nonorthogonal wavelet libraries. However, the library of functions that is based on the high-contrast asymptotic theory is more robust, even for intermediate contrasts, and especially so in the presence of noise. C1 Rice Univ, Houston, TX 77005 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Stanford Univ, Dept Math, Stanford, CA 94305 USA. RP Borcea, L (reprint author), Rice Univ, MS 134,6100 Main St, Houston, TX 77005 USA. EM borcea@caam.rice.edu; berryman@s123.es.llnl.gov; papanicolaou@stanford.edu RI Berryman, James/A-9712-2008 NR 42 TC 23 Z9 24 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0266-5611 EI 1361-6420 J9 INVERSE PROBL JI Inverse Probl. PD AUG PY 1999 VL 15 IS 4 BP 811 EP 849 DI 10.1088/0266-5611/15/4/301 PG 39 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 240AF UT WOS:000082802900001 ER PT J AU Eiden, GC Barinaga, CJ Koppenaal, DW AF Eiden, GC Barinaga, CJ Koppenaal, DW TI Analytical performance of the plasma source RF quadrupole ion trap in elemental and isotopic MS SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article ID MASS-SPECTROMETRY; RESONANCE EJECTION; RESOLUTION; REMOVAL; FIELD AB Recent progress in the development of ion trap ICP-MS instrumentation is presented in terms of performance figures of merit for trace elemental and isotopic analysis. Conventional polyatomic ion interferences are avoided altogether using collisional dissociation techniques inherent to ion trap operation. The current detection limits are in the low pg mL(-1) range, as obtained over extended mass scans using multi-element solutions. The dynamic range linearity is nearly six orders of magnitude using variable injection times to control ion density in the trap. The abundance sensitivity is 10(5) to 10(6) using selective ion monitoring. Other performance figures approach or exceed those of conventional linear quadrupole based ICP-MS instrumentation. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Koppenaal, DW (reprint author), Pacific NW Natl Lab, POB 999,MS P7-07, Richland, WA 99352 USA. NR 22 TC 31 Z9 32 U1 1 U2 4 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD AUG PY 1999 VL 14 IS 8 BP 1129 EP 1132 DI 10.1039/a806433d PG 4 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA 229LP UT WOS:000082196300004 ER PT J AU You, H AF You, H TI Angle calculations for a '4S+2D' six-circle diffractometer SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID X-RAY DIFFRACTOMETER; SURFACE; DIFFRACTION AB Angle calculations are derived for the operation of a '4S+2D' six-circle X-ray or neutron diffractometer. The six degrees of freedom [four sample-orienting ('4S') and two detector-orienting ('2D')] of the diffractometer are used to control the scattering vector and a reference vector in the laboratory frame of reference. Several modes of operation unavailable in other types of diffractometer are presented. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP You, H (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI You, Hoydoo/A-6201-2011 OI You, Hoydoo/0000-0003-2996-9483 NR 10 TC 41 Z9 41 U1 0 U2 11 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD AUG 1 PY 1999 VL 32 BP 614 EP 623 DI 10.1107/S0021889899001223 PN 4 PG 10 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 225LW UT WOS:000081963900004 ER PT J AU Wark, JS Lee, RW AF Wark, JS Lee, RW TI Simulations of femtosecond X-ray diffraction from unperturbed and rapidly heated single crystals SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article AB Simulations are presented of the dynamical diffraction of femtosecond pulses of X-rays from crystals whose structures are modified on similar time scales. Such simulations are of relevance to experiments in which short pulses of X-rays from synchrotron or laser sources are diffracted from rapidly laser-heated crystals. C1 Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Wark, JS (reprint author), Univ Oxford, Dept Phys, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. NR 19 TC 27 Z9 28 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD AUG 1 PY 1999 VL 32 BP 692 EP 703 DI 10.1107/S0021889899002861 PN 4 PG 12 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 225LW UT WOS:000081963900012 ER PT J AU Dinnebier, RE Von Dreele, R Stephens, PW Jelonek, S Sieler, J AF Dinnebier, RE Von Dreele, R Stephens, PW Jelonek, S Sieler, J TI Structure of sodium para-hydroxybenzoate, NaO2C-C6H4OH by powder diffraction: application of a phenomenological model of anisotropic peak width SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID CRYSTAL-STRUCTURE; BENZENE-DERIVATIVES; RIETVELD REFINEMENT; MOLECULAR-STRUCTURE; ACID; STRAIN; SIZE AB The ab initio structure solution of sodium parahydroxybenzoate from high-resolution X-ray powder diffraction data is reported. The compound is of interest with respect to understanding the mechanism of Kolbe-Schmitt type reactions. It crystallizes in space group P2(1), Z = 2, with unit-cell parameters a = 16.0608(3), b = 5.38291 (9), c = 3.63834(6) Angstrom, beta = 92.8692(5)degrees and V = 314.153 Angstrom(3). The compound consists of layers of distorted NaO6 prisms perpendicular to the a axis and phenol rings perpendicular to these layers pointing up and down. The molecular structure is held together by van der Waals forces between the phenyl groups of different layers and additional hydrogen-bridge bonding between the phenolate oxygen atoms. The sample showed powder peak widths which are not a smooth function of diffraction angle; a recently implemented phenomenological model was able to describe this effect sufficiently well to obtain excellent Rietveld fits to the data. The accuracy of modeling the data makes this one of the rare cases where the position of a hydrogen atom could be unambiguously determined by powder techniques. C1 Univ Bayreuth, Crystallog Lab, D-95440 Bayreuth, Germany. Univ Calif Los Alamos Natl Lab, LANSCE, Los Alamos, NM 87545 USA. SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Univ Leipzig, Inst Inorgan Chem, D-04103 Leipzig, Germany. RP Dinnebier, RE (reprint author), Univ Bayreuth, Crystallog Lab, D-95440 Bayreuth, Germany. RI Dinnebier, Robert/B-5642-2015 OI Dinnebier, Robert/0000-0003-2778-2113 NR 38 TC 27 Z9 27 U1 2 U2 4 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD AUG 1 PY 1999 VL 32 BP 761 EP 769 DI 10.1107/S0021889899005233 PN 4 PG 9 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 225LW UT WOS:000081963900019 ER PT J AU Hanson, BL Martin, A Harp, JM Parrish, DA Bunick, CG Kirschbaum, K Pinkerton, AA Bunick, GJ AF Hanson, BL Martin, A Harp, JM Parrish, DA Bunick, CG Kirschbaum, K Pinkerton, AA Bunick, GJ TI Use of an open-flow helium cryostat for macromolecular cryocrystallography SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID CARBONMONOXY-MYOGLOBIN; CRYSTAL-STRUCTURE; PROTEIN AB A helium cryostat developed at the University of Toledo has recently been described by Hardie, Kirschbaum, Martin & Pinkerton [J. Appl. Cryst. (1998), 31, 815-817]. This helium cooling system has now been tested on macromolecules, using crystals of chicken egg lysozyme and sperm whale myoglobin. Phase changes in terbium vanadate crystals indicate that temperatures delivered by the cryostat were less than 33 K. Unit-cell contraction in the protein crystals is consistent with the previously reported He data. Large crystals approaching suitability for neutron diffraction studies were successfully flash-cooled and a large crystal of lysozyme was rescued for data collection after undergoing a cycle of macromolecular crystal annealing (MCA) following poor hash-cooling. Comparison of diffraction data from sperm whale myoglobin crystals collected in both He and N-2 showed a 23% lower overall B factor for the He data. The results of these studies show that this device might be an especially useful adjunct both for neutron diffraction studies and at high-intensity synchrotron X-ray sources, in addition to its use in the standard macromolecular crystallography laboratory. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Univ Toledo, Dept Chem, Toledo, OH 43606 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. Univ Toledo, Dept Chem, Toledo, OH 43606 USA. RP Hanson, BL (reprint author), Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RI Hanson, Bryant Leif/F-8007-2010; OI Hanson, Bryant Leif/0000-0003-0345-3702; pinkerton, alan/0000-0002-2239-1992 NR 16 TC 16 Z9 16 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD AUG 1 PY 1999 VL 32 BP 814 EP 820 DI 10.1107/S0021889899005026 PN 4 PG 7 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 225LW UT WOS:000081963900025 ER PT J AU Whiteman, CD Zhong, SY Bian, XD AF Whiteman, CD Zhong, SY Bian, XD TI Wintertime boundary layer structure in the Grand Canyon SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID AIR-QUALITY; VALLEY; SOUTHWEST; FLOWS; WINDS; BASIN AB Wintertime temperature profiles in the Grand Canyon exhibit a neutral to isothermal stratification during both daytime and nighttime, with only rare instances of actual temperature inversions. The canyon warms during daytime and cools during nighttime more or less uniformly through the canyon's entire depth. This weak stability and temperature structure evolution differ from other Rocky Mountain valleys, which develop strong nocturnal inversions and exhibit convective and stable boundary layers that grow upward from the valley Boor. Mechanisms that may be responsible for the different behavior of the Grand Canyon are discussed, including the possibility that the canyon atmosphere is frequently mixed to near-neutral stratification when cold air drains into the top of the canyon from the nearby snow-covered Kaibab Plateau. Another feature of canyon temperature profiles is the sharp inversions that often form near the canyon rims. These are generally produced when warm air is advected over the canyon in advance of passing synoptic-scale ridges. Wintertime winds in the main canyon are not classical diurnal along-valley wind systems. Rather, they are driven along the canyon axis by the horizontal synoptic-scale pressure gradient that is superimposed along the canyon's axis by passing synoptic-scale weather disturbances. They may thus bring winds into the canyon from either end at any time of day. The implications of the observed canyon boundary layer structure for air pollution dispersion are discussed. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Pacific NW Lab, K9-30,POB 999, Richland, WA 99352 USA. EM Dave.Whiteman@pnl.gov NR 45 TC 22 Z9 22 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 1999 VL 38 IS 8 BP 1084 EP 1102 DI 10.1175/1520-0450(1999)038<1084:WBLSIT>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 233BR UT WOS:000082406100005 ER PT J AU Whiteman, CD Bian, XD Zhong, SY AF Whiteman, CD Bian, XD Zhong, SY TI Wintertime evolution of the temperature inversion in the Colorado Plateau basin SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID LOS-ANGELES BASIN; BOUNDARY-LAYER EVOLUTION; 3-DIMENSIONAL SIMULATIONS; POLLUTANT TRANSPORT; CANYONLAND BASIN; STABLE LAYERS; MODEL; CIRCULATIONS; TERRAIN; BUDGETS AB The Colorado Plateau, surrounded by a ring of mountains, has the meteorological characteristics of a basin. Deep, persistent potential temperature inversions form in this basin in winter. The formation, maintenance, and dissipation of these inversions are investigated using two to four times daily radiosonde data from the winter and early spring of 1989-90. In winter, inversion evolution is forced primarily by synoptic-scale events. The buildup takes place over one or more days as warm air advection occurs above the basin with the approach of high pressure ridges. The breakup, which occurs with cold air advection above the basin as troughs approach, can occur over periods less than 12 h. Many approaching troughs modulate inversion strength and depth but are too weak to destroy the persistent inversion. Later in the winter and spring, the radiation-induced nocturnal inversion is destroyed nearly every day by the daytime growth of convective boundary layers from the basin floor and sidewalls. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Whiteman, CD (reprint author), Pacific NW Lab, K9-30,POB 999, Richland, WA 99352 USA. NR 45 TC 67 Z9 67 U1 2 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 1999 VL 38 IS 8 BP 1103 EP 1117 DI 10.1175/1520-0450(1999)038<1103:WEOTTI>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 233BR UT WOS:000082406100006 ER PT J AU Whiteman, CD Bian, XD Sutherland, JL AF Whiteman, CD Bian, XD Sutherland, JL TI Wintertime surface wind patterns in the Colorado River valley SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID DRAINAGE WINDS; ENERGY BUDGET AB The diurnal variation of regional wind patterns in the complex terrain of the Grand Canyon area was investigated for wintertime fair weather days using a network of wind sensors on 10-m towers. Thermally driven along-slope and along-valley circulations were present at all sites within the region, but wind characteristics varied from site to site depending on nearby topography and exposure. Along the Colorado River upstream from the Grand Canyon, a series of subbasins produce a regional circulation system characterized by convergence of low-level air into the subbasins at night and divergence of air from the subbasins during the day. Contrary to valley wind theory expectations. locations down valley from the subbasin centers experience up-valley winds during nighttime: and down-valley winds during daytime. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Whiteman, CD (reprint author), Pacific NW Lab, K9-20,POB 999, Richland, WA 99352 USA. NR 21 TC 21 Z9 23 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 1999 VL 38 IS 8 BP 1118 EP 1130 DI 10.1175/1520-0450(1999)038<1118:WSWPIT>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 233BR UT WOS:000082406100007 ER PT J AU Kaufmann, P Whiteman, CD AF Kaufmann, P Whiteman, CD TI Cluster-analysis classification of wintertime wind patterns in the Grand Canyon region SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID CLIMATOLOGY; FIELDS AB Twelve typical wintertime wind patterns for the Grand Canyon region were derived from a two-stage cluster analysis wind-field classification scheme. The wind measurements were collected by a surface network of 15 stations deployed for a period of approximately three months. The wind patterns are strongly influenced by the complex terrain of the region. The analyses relate the wind patterns to meteorological conditions, providing insight into the physical processes generating the wind fields. Most patterns have a distinct diurnal cycle, caused by thermally induced winds near the ground. They provide evidence that thermally forced flows are important in winter and are not easily overridden by ambient flows. Some patterns differ primarily in the ratio of high- and low-elevation site wind speeds, indicating the importance of decoupling of the low-elevation winds in this basin area from the stronger ambient winds. C1 Univ Colorado, NOAA, Environm Technol Lab, CIRES, Boulder, CO 80309 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Kaufmann, P (reprint author), Swiss Meteorol Inst, POB 514, CH-8044 Zurich, Switzerland. RI Kaufmann, Pirmin/C-4713-2012 OI Kaufmann, Pirmin/0000-0002-0873-598X NR 13 TC 34 Z9 35 U1 1 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD AUG PY 1999 VL 38 IS 8 BP 1131 EP 1147 DI 10.1175/1520-0450(1999)038<1131:CACOWW>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 233BR UT WOS:000082406100008 ER PT J AU Keim, P Klevytska, AM Price, LB Schupp, JM Zinser, G Smith, KL Hugh-Jones, ME Okinaka, R Hill, KK Jackson, PJ AF Keim, P Klevytska, AM Price, LB Schupp, JM Zinser, G Smith, KL Hugh-Jones, ME Okinaka, R Hill, KK Jackson, PJ TI Molecular diversity in Bacillus anthracis SO JOURNAL OF APPLIED MICROBIOLOGY LA English DT Article; Proceedings Paper CT 3rd International Conference on Anthrax CY SEP 07-10, 1998 CL UNIV PLYMOUTH, PLYMOUTH, ENGLAND SP Soc Appl Microbiol, DERA, Chem & Biol Defence Sector, Ctr Appl Microbiol & Res, Federat European Microbiol Soc, Soc Gen Microbiol, US DOE, US Army Med Res & Mat Command HO UNIV PLYMOUTH ID GENETIC-VARIABILITY; REPEATS AB Molecular typing of Bacillus anthracis is has been extremely difficult due to the lack of polymorphic DNA markers. We have identified nine novel variable number tandemly repeated loci from previously known amplified fragment length polymorphism markers or from the DNA sequence. In combination with the previously known vrrA locus, these markers provide discrimination power to genetically characterize B. anthracis isolates. The variable number tandem repeat (VNTR) loci are found in both gene coding (genic) and non-coding (non-genic) regions, The genic differences are 'in frame' and result in additions or deletion of amino acids to the predicted proteins. Due the rarity of molecular differences, the VNTR changes represent a significant portion of the genetic variation found within B. anthracis. This variation could represent an important adaptive mechanism. Marker similarity and differences among diverse isolates have identified seven major diversity groups that may represent the only world-wide B. anthracis clones. The lineages reconstructed using these data may reflect the dispersal and evolution of this pathogen. C1 No Arizona Univ, Dept Biol Sci, Flagstaff, AZ 86011 USA. Louisiana State Univ, Sch Vet Med, Dept Epidemiol & Community Hlth, Baton Rouge, LA 70803 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Keim, P (reprint author), No Arizona Univ, Dept Biol Sci, Box 5640, Flagstaff, AZ 86011 USA. RI Keim, Paul/A-2269-2010 NR 6 TC 56 Z9 62 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1364-5072 J9 J APPL MICROBIOL JI J. Appl. Microbiol. PD AUG PY 1999 VL 87 IS 2 BP 215 EP 217 DI 10.1046/j.1365-2672.1999.00873.x PG 3 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 237MJ UT WOS:000082659900009 PM 10475952 ER PT J AU Okinaka, R Cloud, K Hampton, O Hoffmaster, A Hill, K Keim, P Koehler, T Lamke, G Kumano, S Manter, D Martinez, Y Ricke, D Svensson, R Jackson, P AF Okinaka, R Cloud, K Hampton, O Hoffmaster, A Hill, K Keim, P Koehler, T Lamke, G Kumano, S Manter, D Martinez, Y Ricke, D Svensson, R Jackson, P TI Sequence, assembly and analysis of pX01 and pX02 SO JOURNAL OF APPLIED MICROBIOLOGY LA English DT Article; Proceedings Paper CT 3rd International Conference on Anthrax CY SEP 07-10, 1998 CL UNIV PLYMOUTH, PLYMOUTH, ENGLAND SP Soc Appl Microbiol, DERA, Chem & Biol Defence Sector, Ctr Appl Microbiol & Res, Federat European Microbiol Soc, Soc Gen Microbiol, US DOE, US Army Med Res & Mat Command HO UNIV PLYMOUTH AB Bacillus anthracis plasmids pX01 and pX02, harboured by the Sterne and Pasteur strains, respectively, have been sequenced by random 'shotgun' cloning and high throughout sequence analysis. These sequences have been assembled (Sequencher) to generate a circulate pX01 plasmid containing 181 656 bp and a single linear (gapped) pX02, contig containing at least 93.479 bp, Initial annotation suggests that the two plasmids combined contain at least 200 potential open reading frames (ORFs) with < 40% having significant similarity to sequences registered in open databases. Collectively, only; 118 566 bp of the pX01 DNA (65%) represent predicted coding regions. This value is similar to published gene densities for other plasmids and is indicative of the larger intergenic spaces in plasmids vs those found in the chromosomes of the parental microbes (85-93% gene density). A 70 kbp region including the toxin genes (cya, lef and pag) is distinct from the remainder of the pX01 sequence: (1) it has a lower gene density (58 as 70%) than the remaining ill kbp; (2) it contains all but one of the co-regulated transcriptional fusions identified by transposon mutagenesis (Hoffmaster and Koehler 1997) and (3) it contains a significantly higher proportion of positive BLAST scores (62 vs 20%) for putative ORFs, These data suggest different origins for the two regions of pX01. C1 Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. No Arizona Univ, Dept Biol, Flagstaff, AZ 86011 USA. Univ Texas, Sch Med, Dept Microbiol & Mol Genet, Houston, TX USA. RP Okinaka, R (reprint author), Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. RI Keim, Paul/A-2269-2010 NR 4 TC 102 Z9 169 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1364-5072 J9 J APPL MICROBIOL JI J. Appl. Microbiol. PD AUG PY 1999 VL 87 IS 2 BP 261 EP 262 DI 10.1046/j.1365-2672.1999.00883.x PG 2 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 237MJ UT WOS:000082659900019 PM 10475962 ER PT J AU Jackson, PJ Hill, KK Laker, MT Ticknor, LO Keim, P AF Jackson, PJ Hill, KK Laker, MT Ticknor, LO Keim, P TI Genetic comparison of Bacillus anthracis and its close relatives using amplified fragment length polymorphism and polymerase chain reaction analysis SO JOURNAL OF APPLIED MICROBIOLOGY LA English DT Article; Proceedings Paper CT 3rd International Conference on Anthrax CY SEP 07-10, 1998 CL UNIV PLYMOUTH, PLYMOUTH, ENGLAND SP Soc Appl Microbiol, DERA, Chem & Biol Defence Sector, Ctr Appl Microbiol & Res, Federat European Microbiol Soc, Soc Gen Microbiol, US DOE, US Army Med Res & Mat Command HO UNIV PLYMOUTH AB Amplified fragment length polymorphism (AFLP) analysis allows a rapid, relatively simple analysis of a large portion of a microbial genome, providing information about the species and its phylogenetic relationship to other microbes (Vos et nl. 1995). The method simply surveys the genome for length and sequence polymorphisms. The AFLP pattern identified can be used for comparison to the genomes of other species. Unlike other methods, it does not rely on analysis of a single genetic locus that ma) bias the interpretation of results and does not require any prior knowledge of the targeted organism. Moreover, a standard set of reagents can be applied to any species without using species-specific information or molecular probes. We are using AFLP analysis to rapidly identify different bacterial species. A comparison of AFLP profiles generated from a large battery of Bacillus anthracis strains shows very little variability among different isolates (Keim et al. 1997). By contrast, there is a significant difference between AFLP profiles generated for any B. anthracis strain and even the most closely related Bacillus species. Sufficient variability is apparent among all known microbial species to allow phylogenetic anal! sis based on large numbers of genetically unlinked loci. These striking differences among AFLP profiles allow unambiguous identification of previously identified species and phylogenetic placement of newly characterized isolates relative to known species based on a large number of independent genetic loci. Data generated thus fat show that the method provides phylogenetic analyses that are consistent with other widely accepted phylogenetic methods. However, AFLP analysis provides a more detailed analysis of the targets and samples a much larger portion of the genome. Consequently, it provides an inexpensive, rapid means of characterizing microbial isolates to further differentiate among strains and closely related microbial species. Such information cannot be rapidly generated by other means. AFLP sample analysis quickly generates a very large amount of molecular information about microbial genomes. However, this information cannot be analysed rapidly using manual methods. We are developing a large archive of electronic AFLP signatures that is being used to identify isolates collected from medical, veterinary, forensic and environmental samples. We are also developing the computational packages necessary to rapidly and unambiguously analyse the AFLP profiles and conduct a phylogenetic comparison of these data relative to information already in our database. We will use this archive and the associated algorithms to determine the species identity of previously uncharacterized isolates and place them phylogenetically relative to other microbes based on their AFLP signatures. This study provides significant new information about microbes with environmental, veterinary and medical significance. This information can be used in further studies to understand the relationships among these species and the factors that distinguish them from one another. It should also allow the identification of unique factors that contribute to important microbial traits, including pathogenicity and virulence. We are also using AFLP data to identify, isolate and sequence DNA fragments that are unique to particular microbial species and strains. The fragment patterns and sequence information provide insights into the complexity and organization of bacterial genomes relative to one another. They also provide the information necessary for the development of species-specific polymerase chain reaction primers that can be used to interrogate complex samples for the presence of B. anthracis, other microbial pathogens or their remnants. C1 Univ Calif Los Alamos Natl Lab, Environm Mol Biol Grp, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Stat Sci Grp, Los Alamos, NM 87545 USA. No Arizona Univ, Dept Biol Sci, Flagstaff, AZ 86011 USA. RP Jackson, PJ (reprint author), Univ Calif Los Alamos Natl Lab, Environm Mol Biol Grp, POB 1663, Los Alamos, NM 87545 USA. RI Keim, Paul/A-2269-2010 NR 6 TC 47 Z9 50 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 1364-5072 J9 J APPL MICROBIOL JI J. Appl. Microbiol. PD AUG PY 1999 VL 87 IS 2 BP 263 EP 269 DI 10.1046/j.1365-2672.1999.00884.x PG 7 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 237MJ UT WOS:000082659900020 PM 10475963 ER PT J AU Findikoglu, AT Reagor, DW Rasmussen, KO Bishop, AR Gronbech-Jensen, N Jia, QX Fan, Y Kwon, C Ostrovsky, LA AF Findikoglu, AT Reagor, DW Rasmussen, KO Bishop, AR Gronbech-Jensen, N Jia, QX Fan, Y Kwon, C Ostrovsky, LA TI Electrodynamic properties of coplanar waveguides made from high-temperature superconducting YBa2Cu3O7-delta electrodes on nonlinear dielectric SrTiO3 substrates SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THIN-FILMS; TRANSMISSION-LINES; MICROWAVE DEVICES; DISPERSION CHARACTERISTICS; FERROELECTRICS; LAALO3 AB We present a comprehensive study of broadband (0-2 GHz) electrodynamic properties of coplanar waveguides made from high-temperature superconducting thin-film YBa2Cu3O7-delta electrodes on nonlinear dielectric single-crystal SrTiO3 substrates. The waveguides exhibit strong dielectric nonlinearities, in addition to temperature-, dc-bias-, and frequency-dependent dissipation and refractive index. By using parameters determined from small-signal (linear) transmission characteristics of the waveguides as a function of dc bias, we develop a model equation that successfully predicts and describes large-signal (nonlinear) behavior. (C) 1999 American Institute of Physics. [S0021-8979(99)03615-4]. C1 Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, Elect & Electrochem Mat & Devices Grp, Los Alamos, NM 87544 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Condensed Matter & Stat Phys Grp, Los Alamos, NM 87544 USA. Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, Supercond Technol Ctr, Los Alamos, NM 87544 USA. Univ Calif Los Alamos Natl Lab, Inst Geophys & Planetary Phys, Los Alamos, NM 87545 USA. Univ Colorado, Environm Technol Lab, Boulder, CO 80303 USA. RP Findikoglu, AT (reprint author), Univ Calif Los Alamos Natl Lab, Mat Sci & Technol Div, Elect & Electrochem Mat & Devices Grp, POB 1663, Los Alamos, NM 87544 USA. RI Rasmussen, Kim/B-5464-2009; Jia, Q. X./C-5194-2008 OI Rasmussen, Kim/0000-0002-4029-4723; NR 47 TC 11 Z9 11 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1999 VL 86 IS 3 BP 1558 EP 1568 DI 10.1063/1.370967 PG 11 WC Physics, Applied SC Physics GA 216TD UT WOS:000081458800066 ER PT J AU Gopalan, V Gerstl, SSA Itagi, A Mitchell, TE Jia, QX Schlesinger, TE Stancil, DD AF Gopalan, V Gerstl, SSA Itagi, A Mitchell, TE Jia, QX Schlesinger, TE Stancil, DD TI Mobility of 180 degrees domain walls in congruent LiTaO3 measured using real-time electro-optic imaging microscopy SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LINBO3 CRYSTALS; INTERNAL FIELD; ORIGIN AB We report the electric-field dependence of 180 degrees domain-wall mobility in congruent LiTaO3 measured at room temperature using in situ electro-optic imaging microscopy. The measured sideways domain-wall velocity of serrated domain fronts formed upon merger of domains was an order of magnitude larger than that for independently growing domains. The wall velocities also show a strong dependence on the nature of the applied electric field, being an order of magnitude larger for steady-state voltages as compared to pulsed voltage measurements. This is shown to be due to wall stabilization between applied voltage pulses resulting in an inertial delay in moving a domain wall which has been at rest for many seconds. (C) 1999 American Institute of Physics. [S0021-8979(99)03215-6]. C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. Carnegie Mellon Univ, Dept Engn & Publ Policy, Pittsburgh, PA 15213 USA. Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. Carnegie Mellon Univ, Dept Elect & Comp Engn, Pittsburgh, PA 15213 USA. RP Gopalan, V (reprint author), Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RI Stancil, Daniel/D-1339-2013; Jia, Q. X./C-5194-2008; OI Stancil, Daniel/0000-0002-2010-1381; , Daniel/0000-0001-7741-1893 NR 16 TC 21 Z9 21 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1999 VL 86 IS 3 BP 1638 EP 1646 DI 10.1063/1.370940 PG 9 WC Physics, Applied SC Physics GA 216TD UT WOS:000081458800078 ER PT J AU Fitz-Gerald, JM Rack, PD Trottier, TA Ollinger, M Pennycook, SJ Gao, H Singh, RK AF Fitz-Gerald, JM Rack, PD Trottier, TA Ollinger, M Pennycook, SJ Gao, H Singh, RK TI Synthesis of spherical luminescent particulate coatings SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LASER-ABLATION AB In this communication, we show the feasibility of the pulsed laser ablation technique to make very thin, uniform luminescent coatings on particulate systems. To deposit continuous particulate coatings, the laser-induced plume from the target comes in contact with an agitated bed of core particles (size 1 mu m). The pressure and nature of the background gas (inert or active! controls the cluster size of the particles in the laser plume. Experiments were conducted for laser deposition of phosphor nanoparticles on SiO2 core particles by pulsed excimer laser wavelength=248 nm and pulse duration=25 ns) irradiation of a yttria: Eu (Y2O3:Eu3+) sputtering target. (C) 1999 American Institute of Physics. [S0021-8979(99)04815-X]. C1 USN, Res Lab, Washington, DC 20375 USA. Rochester Inst Technol, Dept Microelect Engn, Rochester, NY 14623 USA. Motorola Inc, Flat Panel Display Div, Tempe, AZ 85284 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Fitz-Gerald, JM (reprint author), USN, Res Lab, Code 6372,Bldg 74, Washington, DC 20375 USA. NR 12 TC 11 Z9 11 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD AUG 1 PY 1999 VL 86 IS 3 BP 1759 EP 1761 DI 10.1063/1.370959 PG 3 WC Physics, Applied SC Physics GA 216TD UT WOS:000081458800097 ER PT J AU Gunneweg, J Michel, HV AF Gunneweg, J Michel, HV TI Does the different layout of the Late Bronze Age tombs at Laish/Dan and Akko in Northern Canaan reflect different trade relations? An instrumental neutron activation study on Mycenaean pottery SO JOURNAL OF ARCHAEOLOGICAL SCIENCE LA English DT Article; Proceedings Paper CT International Symposium on Archaeometry CY MAY 20-24, 1996 CL NIV ILLINOIS URBANA CHAMPAIGN, URBANA, ILLINOIS HO NIV ILLINOIS URBANA CHAMPAIGN DE provenance; neutron activation analysis; Late Bronze Age; Mycenaean; pottery C1 Hebrew Univ Jerusalem, Archaeol Inst, IL-91905 Jerusalem, Israel. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Gunneweg, J (reprint author), Hebrew Univ Jerusalem, Archaeol Inst, IL-91905 Jerusalem, Israel. NR 22 TC 6 Z9 6 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0305-4403 J9 J ARCHAEOL SCI JI J. Archaeol. Sci. PD AUG PY 1999 VL 26 IS 8 BP 989 EP 995 DI 10.1006/jasc.1999.0420 PG 7 WC Anthropology; Archaeology; Geosciences, Multidisciplinary SC Anthropology; Archaeology; Geology GA 234ED UT WOS:000082470800014 ER PT J AU Turner, DD Goldsmith, JEM AF Turner, DD Goldsmith, JEM TI Twenty-four-hour Raman lidar water vapor measurements during the Atmospheric radiation Measurement program's 1996 and 1997 water vapor intensive observation periods SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID AEROSOLS; SYSTEM; SENSITIVITY AB Prior to the Atmospheric Radiation Measurement program's first water vapor intensive observation period (WVIOP) at the Cloud and Radiation Testbed site near Lament, Oklahoma, an automated 24-h Raman lidar was delivered to the site. This instrument, which makes high-resolution measurements of water vapor both spatially and temporally, is capable of making these measurements with no operator interaction (other than initial startup) for days at a time. Water vapor measurements collected during the 1996 and 1997 WVIOPs are discussed here, illustrating both the nighttime and daytime capabilities of this system. System characteristics, calibration issues, and techniques are presented. Finally, detailed intercomparisons of the lidar's data with those from a microwave radiometer, radiosondes, an instrumented tower, a chilled mirror flown on both a tethersonde and kite, and measurements from aircraft are shown and discussed, highlighting the accuracy and stability of this system for both nighttime and daytime measurements. C1 Pacific NW Lab, Richland, WA 99352 USA. Sandia Natl Labs, Livermore, CA USA. RP Turner, DD (reprint author), Pacific NW Lab, POB 999,MS K7-28, Richland, WA 99352 USA. NR 23 TC 77 Z9 77 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD AUG PY 1999 VL 16 IS 8 BP 1062 EP 1076 DI 10.1175/1520-0426(1999)016<1062:TFHRLW>2.0.CO;2 PG 15 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 231EJ UT WOS:000082294900006 ER PT J AU Haynes, JA Rigney, ED Janowski, GM AF Haynes, JA Rigney, ED Janowski, GM TI Effects of cyclic bending and physiological solution on plasma-sprayed hydroxylapatite coatings of varying crystallinity SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE plasma-sprayed coatings; hydroxylapatite; calcium phosphate; dental implants; biomaterials ID CALCIUM-PHOSPHATE; HYDROXYAPATITE COATINGS; TITANIUM; DISSOLUTION; IMPLANTS AB This study investigated the effects of cyclic bending stress levels and testing in simulated physiological solutions or air on the integrity of plasma-sprayed hydroxylapatite (HA) coatings of two different crystallinities. Hydroxylapatite-coated commercially pure (CP) Ti rods were evaluated by immersion testing in Hank's Balanced Salt Solution (HBSS) and by rotating bending in air and HBSS, Static immersion testing of nonstressed specimens resulted in significant microcracking of coating surfaces after 42 days. Specimens cyclically tested at bending stresses above the yield strength of Ti experienced low cycle fatigue failure of the Ti substrates prior to spallation of the HA coatings. Coatings tested at 1 x 10(6) cycles with interface bending stresses of 180 MPa displayed increased surface microcracking, but no bulk coating spallation, Coatings cycled in HBSS displayed greater amounts of microcracking and surface alteration than samples cycled in air. There was no apparent relation between HA crystallinity and mechanical integrity under cyclic bending stresses. (C) 1999 John Wiley & Sons, Inc. C1 Univ Alabama, Dept Mech & Mat Engn, Birmingham, AL 35294 USA. RP Haynes, JA (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Janowski, Gregg/A-6354-2011 OI Janowski, Gregg/0000-0001-8384-4820 NR 24 TC 7 Z9 7 U1 1 U2 7 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD AUG PY 1999 VL 48 IS 4 BP 403 EP 410 DI 10.1002/(SICI)1097-4636(1999)48:4<403::AID-JBM2>3.0.CO;2-F PG 8 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 216KG UT WOS:000081440800002 PM 10421680 ER PT J AU Wang, RR Welsch, GE Monteiro, O AF Wang, RR Welsch, GE Monteiro, O TI Silicon nitride coating on titanium to enable titanium-ceramic bonding SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE silicon nitride coating; titanium-ceramic interface; oxidation ID RESTORATIONS; ALLOY AB Failures that occur in titanium-ceramic restorations are of concern to clinicians. The formation of poorly adhering oxide on titanium at dental porcelain sintering temperatures causes adherence problems between titanium and porcelain, which is the main limiting factor in the fabrication of titanium-ceramic restorations. To overcome this problem a 1-mu m thick Si3N4 coating was applied to a titanium surface using a plasma-immersion implantation and deposition method. Such a coating serves as an oxygen diffusion barrier on titanium during the porcelain firings. The protective coating Mras characterized in the as-deposited condition and after thermal cycling. Cross sections of Ti/Si3N4-porcelain interface regions were examined by various electron microscopy methods and by energy dispersive analysis of X-rays to study the Si3N4 film's effectiveness in preventing titanium oxidation and in forming a bond with porcelain. The experiments have shown that this Si3N4 coating enables significant improvement in Ti-ceramic bonding. (C) 1999 John Wiley & Sons, Inc. C1 Case Western Reserve Univ, Sch Dent, Dept Restorat Dent, Cleveland, OH 44106 USA. Case Western Reserve Univ, Sch Engn, Dept Mat Sci & Engn, Cleveland, OH 44106 USA. Lawrence Berkeley Lab, Plasma Applicat Grp, Berkeley, CA 94720 USA. RP Wang, RR (reprint author), Case Western Reserve Univ, Sch Dent, Dept Restorat Dent, 10900 Euclid Ave, Cleveland, OH 44106 USA. FU NIDCR NIH HHS [DE11032] NR 21 TC 77 Z9 84 U1 1 U2 12 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD AUG PY 1999 VL 46 IS 2 BP 262 EP 270 DI 10.1002/(SICI)1097-4636(199908)46:2<262::AID-JBM16>3.0.CO;2-1 PG 9 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 200QM UT WOS:000080551600016 PM 10380005 ER PT J AU Jacobs, DM Lipton, AS Isern, NG Daughdrill, GW Lowry, DF Gomes, X Wold, MS AF Jacobs, DM Lipton, AS Isern, NG Daughdrill, GW Lowry, DF Gomes, X Wold, MS TI Human replication protein A: Global fold of the N-terminal RPA-70 domain reveals a basic cleft and flexible C-terminal linker SO JOURNAL OF BIOMOLECULAR NMR LA English DT Article DE backbone assignments; DNA recombination; DNA repair; DNA replication; RPA; RPA70; secondary structure ID TRIPLE-RESONANCE NMR; SV40 DNA-REPLICATION; SACCHAROMYCES-CEREVISIAE; N-15-LABELED PROTEINS; IMPROVED SENSITIVITY; FUNCTIONAL DOMAINS; BACKBONE DYNAMICS; FACTOR-A; SPECTROSCOPY; RECOMBINATION AB Human Replication Protein A (hsRPA) is required for multiple cellular processes in DNA metabolism including DNA repair, replication and recombination. It binds single-stranded DNA with high affinity and interacts specifically with multiple proteins. hsRPA forms a heterotrimeric complex composed of 70-, 32- and 14-kDa subunits (henceforth RPA70, RPA32, and RPA14). The N-terminal 168 residues of RPA70 form a structurally distinct domain that stimulates DNA polymerase alpha activity, interacts with several transcriptional activators including tumor suppressor p53, and during the cell cycle it signals escape from the DNA damage induced G2/M checkpoint. We have solved the global fold of the fragment corresponding to this domain (RPA70 Delta 169) and we find residues 8-108 of the N-terminal domain are structured. The remaining C-terminal residues are unstructured and may form a flexible linker to the DNA-binding domain of RPA70. The globular region forms a five-stranded anti-parallel beta-barrel. The ends of the barrel are capped by short helices. Two loops on one side of the barrel form a large basic cleft which is a likely site for binding the acidic motifs of transcriptional activators. Many lethal or conditional lethal yeast point mutants map to this cleft, whereas no mutations with severe phenotype have been found in the linker region. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Iowa, Coll Med, Dept Biochem, Iowa City, IA 52240 USA. RP Lowry, DF (reprint author), Pacific NW Lab, Environm Mol Sci Lab, 902 Battelle Blvd, Richland, WA 99352 USA. RI Wold, Marc/F-5806-2010; Isern, Nancy/J-8016-2013; OI Isern, Nancy/0000-0001-9571-8864 NR 44 TC 72 Z9 73 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0925-2738 J9 J BIOMOL NMR JI J. Biomol. NMR PD AUG PY 1999 VL 14 IS 4 BP 321 EP 331 DI 10.1023/A:1008373009786 PG 11 WC Biochemistry & Molecular Biology; Spectroscopy SC Biochemistry & Molecular Biology; Spectroscopy GA 234VK UT WOS:000082504900003 PM 10526407 ER PT J AU Click, DR Scott, BL Watkin, JG AF Click, DR Scott, BL Watkin, JG TI Formation of a samarium alkoxide-aryloxide complex containing a novel butterfly framework: X-ray crystal structures of Sm-4(mu(3)-O-i-Pr)(3)(mu(2)-O-i-Pr)(4)(O-i-Pr)(2) (O-2,6-i-Pr2C6H3)(3)(THF) and [Ti(O-i-Pr)(2)(O-2,6-i-Pr2C6H3) (mu-O-i-Pr)](2) SO JOURNAL OF CHEMICAL CRYSTALLOGRAPHY LA English DT Article DE samarium; titanium; alkoxide; alcoholysis; butterfly ID MICROWAVE DIELECTRIC-PROPERTIES; MOLECULAR-STRUCTURE; THIN-FILMS; YTTRIUM; SM; REACTIVITY; OXIDE; TITANIUM(IV); DERIVATIVES; DIFFRACTION AB Reaction of a 1:1 mixture of Sm[N(SiMe3)(2)](3) and Ti(O-i-Pr)(4) with three equivalents of 2,6-di-iso-propylphenol, followed by crystallization from hexane/THF, leads to isolation of the tetranuclear samarium alkoxide Sm-4(mu(3)-O-i-Pr)(3)(mu(2)-O-i-Pr)(4)(O-i-Pr)(2)(O-2,6-i-Pr2C6H3)(3) (THF) (1), in addition to the dimeric titanium alkoxide [Ti(O-i-Pr)(2)(O-2,6-i-Pr2C6H3)(mu-O-i-Pr)](2) (2). 1 crystallizes in the space group P (1) over bar while 2 crystallizes in space group P2(1)/c Cell parameters for 1: a = 15.928(6) b = 17.677(7), c = 18.99(1) Angstrom, alpha = 113.24(3), beta = 94.99(4), gamma = 109.59(2)degrees, V = 4477(4) Angstrom(3), D-calc = 1.350 Mg/m(3), and Z = 2. Cell parameters for 2: a = 25.336(2), b = 12.082(1), c = 15.570(2) Angstrom, beta = 96.510(8)degrees, V = 4735.4(8) Angstrom 3, D-calc = 1.129 mg/m(3), and Z = 4. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87544 USA. RP Watkin, JG (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Mail Stop J514, Los Alamos, NM 87544 USA. RI G, Neela/H-3016-2014; Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 38 TC 5 Z9 5 U1 0 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1074-1542 J9 J CHEM CRYSTALLOGR JI J. Chem. Crystallogr. PD AUG PY 1999 VL 29 IS 8 BP 921 EP 929 DI 10.1023/A:1009530112983 PG 9 WC Crystallography; Spectroscopy SC Crystallography; Spectroscopy GA 304AE UT WOS:000086459700009 ER PT J AU Song, Y Evans, M Ng, CY Hsu, CW Jarvis, GK AF Song, Y Evans, M Ng, CY Hsu, CW Jarvis, GK TI Rotationally resolved pulsed field ionization photoelectron bands of O-2(+)(X (2)Pi(1/2,3/2g), v(+)=0-38) in the energy range of 12.05-18.15 eV SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HIGH-RESOLUTION THRESHOLD; SYNCHROTRON-RADIATION; COHERENT XUV; PHOTOIONIZATION; SPECTROSCOPY; O-2; OXYGEN; MOLECULES; SPECTRUM; DYNAMICS AB We have obtained rotationally resolved pulsed field ionization photoelectron (PFI-PE) spectra for O-2 in the energy range of 12.05-18.15 eV, covering ionization transitions O-2(+)(X (2)Pi(1/2,3/2g), v(+)=0-38,J(+))<-- O-2(X (3)Sigma(g)(-), v(+)=0,N"). While the PFI-PE bands for O-2(+)(X (2)Pi(1/2,3/2g), v(+)=3-5, 9, 11, 12, 22, and 25-38) reported here are the first rotational-resolved photoelectron measurements, the PFI-PE bands for O-2(+)(X (2)Pi(1/2,3/2g), v(+)=25-38) represent the first rotationally resolved spectroscopic data for these states. The simulation of spectra obtained at rotational temperatures of approximate to 20 and 220 K allows the unambiguous identification of O-2(+)(X (2)Pi(1/2,3/2g), v(+)greater than or equal to 21) PFI-PE bands, the majority of which overlap with prominent PFI-PE bands for O-2(+)(A (2)Pi(u), v(+)=0-12) and O-2(+)(a (4)Pi(u), v(+)=0-18). Combined with spectroscopic data obtained in the previous emission study and the present PFI-PE experiment, we have obtained accurate Dunham-type expansion coefficients for ionization energies, vibrational constants, rotational constants, and spin-orbit splitting constants covering the O-2(+)(X (2)Pi(1/2,3/2g), v(+)=0-38) states. Significant local intensity enhancements due to near-resonant autoionization were observed in PFI-PE bands for O-2(+)(X (2)Pi(1/2,3/2g), v(+)=0-14). The energy region of these states is known to manifest a high density of very strong autoionizing low-n-Rydberg states. The observation of a long PFI-PE vibrational progression with a relatively smooth band intensity profile is also in accord with the direct excitation model for the production of highly vibrationally excited O-2(+)(X (2)Pi(1/2,3/2g)) states in the Franck-Condon gap region. Since this experiment was carried out under relatively high rotational temperatures for O-2, the PFI-PE data reveal higher rotational transitions and numerous local intensity enhancements, which were not observed in previous vacuum ultraviolet laser studies using a cold O-2 molecular beam. The rotational branches found here indicate that photoelectrons are formed predominantly in continuum states with orbital angular momenta l=1,3, and 5. (C) 1999 American Institute of Physics. [S0021-9606(99)00929-0]. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Ng, CY (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. NR 39 TC 43 Z9 44 U1 0 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1999 VL 111 IS 5 BP 1905 EP 1916 DI 10.1063/1.479459 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 220ZA UT WOS:000081698700014 ER PT J AU Jarvis, GK Song, Y Ng, CY AF Jarvis, GK Song, Y Ng, CY TI Rotational-resolved pulsed field ionization photoelectron study of NO+(a(3)Sigma(+),v(+)=0-16) in the energy range of 15.6-18.2 eV SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SYNCHROTRON-RADIATION; SPECTROSCOPY; THRESHOLD; PHOTOIONIZATION; NO+; BANDS; IONS AB We have obtained rotationally resolved pulsed field ionization photoelectron (PFI-PE) spectra of NO in the energy range of 15.6-18.2 eV, covering ionization transitions of NO+(a (3)Sigma(+),v(+)=0-16,J(+))<-- NO(X (2)Pi(3/2,1/2),v"=0,J"). The PFI-PE bands for NO+(a (3)Sigma(+),v(+)=1-5,7-10,12-14,16) obtained in this experiment represent the first rotationally resolved spectroscopic data for these states. The simulation of these PFI-PE bands provides accurate molecular constants for NO+(a (3)Sigma(+),v(+)=0-5,7-10,12-14,16), including ionization energies, vibrational constants (omega(e)(+)=1295.2 +/- 0.1 cm(-1), omega(e)(+)chi(e)(+)=15.198 +/- 0.002 cm(-1)), and rotational constants (B-e(+)=1.3501 +/- 0.0070 cm(-1), alpha(e)(+)=0.0206 +/- 0.0001 cm(-1)). As observed in the PFI-PE study of NO+(X (1)Sigma(+)), this experiment reveals a generally increasing trend for the maximum Delta J value and intensities of higher Delta J branches as v(+) (or bond distance) for NO+(a (3)Sigma(+)) is increased. This observation can be taken as strong support of the electron-molecular-ion-core scattering model for angular momentum and energy exchanges in the threshold photoionization of NO. (C) 1999 American Institute of Physics. [S0021-9606(99)01027-2]. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Ng, CY (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. NR 28 TC 15 Z9 15 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1999 VL 111 IS 5 BP 1937 EP 1946 DI 10.1063/1.479462 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 220ZA UT WOS:000081698700017 ER PT J AU Laaksonen, A McGraw, R Vehkamaki, H AF Laaksonen, A McGraw, R Vehkamaki, H TI Liquid-drop formalism and free-energy surfaces in binary homogeneous nucleation theory SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MULTICOMPONENT SYSTEMS; REVERSIBLE WORK; WATER; VAPOR; ETHANOL; CLUSTER; NUCLEUS; PHASE AB Three different derivations of the classical binary nucleation theory are considered in detail. It is shown that the derivation originally presented by Wilemski [J. Chem. Phys. 80, 1370 (1984)] is consistent with more extensive derivations [Oxtoby and Kashchiev, J. Chem. Phys. 100, 7665 (1994)]; Debenedetti, Metastable Liquids: Concepts and Principles (Princeton University Press, Princeton, 1996) if and only if the assumption is made that the surface of tension of the binary nucleus coincides with the dividing surface specified by the surface condition Sigma n(si)v(li)=0, where the n(si) denote surface excess numbers of molecules of species i, and the v's are partial molecular volumes. From this condition, it follows that (1) the surface tension is curvature independent and (2) that the nucleus volume is V=Sigma n(li)v(li)=Sigma g(i)v(li), where the n(li) are the numbers of molecules in the uniform liquid phase of the droplet model encompassed by the surface of tension, and the g(i) are the total molecular occupation numbers contained by the nucleus. We show, furthermore, that the above surface condition leads to explicit formulas for the surface excess numbers n(si) in the nucleus. Computations for the ethanol-water system show that the surface number for water molecules (n(s,H2O)) causes the negative occupation numbers (g(H2O)) obtained earlier using the classical nucleation theory. The unphysical behavior produced by the classical theory for surface active systems is thus a direct consequence of the assumption of curvature independence of surface tension. Based on the explicit formulas for n(si), we calculate the full free-energy surfaces for binary nucleation in the revised classical theory and compare these with the free-energy surfaces in the Doyle (unrevised classical) theory. Significant differences in nucleus size and composition are found between these models and they are related to surface excess density. It is shown that only for the revised classical theory is the nucleus composition consistent with the Gibbs dividing surface model. (C) 1999 American Institute of Physics. [S0021-9606(99)51029-5]. C1 Univ Kuopio, Dept Appl Phys, FIN-70211 Kuopio, Finland. Univ Helsinki, Dept Phys, Helsinki 00014, Finland. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. UCL, Dept Phys & Astron, London WC1E 6BT, England. RP Laaksonen, A (reprint author), Univ Kuopio, Dept Appl Phys, POB 1627, FIN-70211 Kuopio, Finland. RI Laaksonen, Ari/B-5094-2011; Vehkamaki, Hanna/A-8262-2008 OI Laaksonen, Ari/0000-0002-1657-2383; Vehkamaki, Hanna/0000-0002-5018-1255 NR 18 TC 66 Z9 67 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1999 VL 111 IS 5 BP 2019 EP 2027 DI 10.1063/1.479470 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 220ZA UT WOS:000081698700027 ER PT J AU Tsekouras, AA Iedema, MJ Cowin, JP AF Tsekouras, AA Iedema, MJ Cowin, JP TI Soft-landed ion diffusion studies on vapor-deposited hydrocarbon films SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ALKANES; BEAM; ICE AB Cesium and hydronium ions were deposited with a "soft-landing" ion beam (1 eV) on n-hexane and 3-methyl-pentane vapor-deposited thin films on a Pt (111) surface at 27 K. Dielectric properties and ion migration were studied during the ion deposition and during a temperature ramp up to the desorption temperature of the molecular films. The ions were found to migrate through amorphous versions of these films as expected by simple viscosity models near 90 K with ion mobilities of about 10(-18) m(2) V-1 s(-1). No, or very limited, diffusion was observed through crystalline films. The n-hexane films crystallize during the ion motion. Analysis of this permits the estimation that average diffusional motion for a neutral hexane during crystallization is about 1 molecular diameter. (C) 1999 American Institute of Physics. [S0021-9606(99)72127-6]. C1 Univ Athens, Phys Chem Lab, GR-15771 Athens, Greece. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Tsekouras, AA (reprint author), Univ Athens, Phys Chem Lab, GR-15771 Athens, Greece. OI Tsekouras, Athanassios/0000-0002-4757-324X NR 22 TC 21 Z9 21 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 1 PY 1999 VL 111 IS 5 BP 2222 EP 2234 DI 10.1063/1.479494 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 220ZA UT WOS:000081698700051 ER PT J AU Langry, K Rambabu, B AF Langry, K Rambabu, B TI Ionic optodes: role in fiber optic chemical sensor technology SO JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY LA English DT Review DE fiber optic chemical sensors; optodes; aqueous ion sensing ID RESPONSIVE FLUORESCENT COMPOUNDS; SUPPORTED LIQUID MEMBRANES; SELECTIVE BULK OPTODES; LIPOPHILIC ANIONIC DYE; PHOTOPHYSICAL PROPERTIES; IMMOBILIZED MORIN; NEUTRAL IONOPHORE; ENERGY-TRANSFER; CATION BINDING; CROWN ETHERS AB Fiber optic chemical sensors and solid state devices are two versatile sensing technologies for detecting analytes in a host of media. Obvious differences distinguish these technologies: however, they share significant features and issues related to analyte identification and selectivity. This report reviews transduction schemes used in fiber optic sensors for monitoring aqueous ionic species and examines some critical concerns that may hinder commercial acceptance. (C) 1999 Society of Chemical Industry. C1 Southern Univ, Dept Phys, Surface Sci Spect & Solid State Ion Lab, Baton Rouge, LA 70813 USA. Univ Calif Lawrence Livermore Natl Lab, Chem & Biol Detect Grp, Livermore, CA 94550 USA. RP Rambabu, B (reprint author), Southern Univ, Dept Phys, Surface Sci Spect & Solid State Ion Lab, Baton Rouge, LA 70813 USA. NR 87 TC 2 Z9 2 U1 0 U2 3 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0268-2575 J9 J CHEM TECHNOL BIOT JI J. Chem. Technol. Biotechnol. PD AUG PY 1999 VL 74 IS 8 BP 717 EP 732 DI 10.1002/(SICI)1097-4660(199908)74:8<717::AID-JCTB105>3.0.CO;2-W PG 16 WC Biotechnology & Applied Microbiology; Chemistry, Multidisciplinary; Engineering, Environmental; Engineering, Chemical SC Biotechnology & Applied Microbiology; Chemistry; Engineering GA 226GL UT WOS:000082011900001 ER PT J AU Xiao, CB Simonson, JM Tremaine, PR AF Xiao, CB Simonson, JM Tremaine, PR TI Densities and apparent molar volumes of Gd(CF3SO3)(3)(aq) at T = (373, 423, and 472) K and p = (7 and 26) MPa SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE Gd(CF3SO3)(3)(aq); density; molar volume; high temperature ID THERMODYNAMIC PROPERTIES; HEAT-CAPACITIES; HIGH-PRESSURES; 283 K; TEMPERATURES; TRIFLUOROMETHANESULFONATE; ELECTROLYTES; NACL(AQ); EQUATION; CHLORIDE AB Densities of Gd(CF3SO3)(3)(aq) solutions with molalities between (0.058 and 0.72) mol kg(-1) were measured with a vibrating-tube densimeter at the temperatures (373, 423, and 473) K and pressures (7 and 26) MPa. Apparent molar volumes calculated from measured densities in this work and those at ambient conditions reported previously by us were represented with the Pitzer ion-interaction treatment. The temperature and pressure dependence of the standard partial molar volume and the virial coefficients in the Pitzer equation were expressed by empirical functions in which the compressibility of water was used as an independent variable. The conventional standard partial molar volume V-m(O)(Gd3+, aq) from T = 278 K to T = 473 K was calculated from V-2,m(O){Gd(CF3SO3)(3), aq} and V-m(O)(CF3SO3-, aq). (C) 1999 Academic Press. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Simonson, JM (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Tremaine, Peter/F-9814-2015 NR 26 TC 6 Z9 6 U1 0 U2 3 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD AUG PY 1999 VL 31 IS 8 BP 1055 EP 1065 DI 10.1006/jcht.1999.0509 PG 11 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 225UE UT WOS:000081982300007 ER PT J AU Fowler, JS Volkow, ND Ding, YS Wang, GJ Dewey, S Fischman, MW Foltin, R Hitzemann, R AF Fowler, JS Volkow, ND Ding, YS Wang, GJ Dewey, S Fischman, MW Foltin, R Hitzemann, R TI Positron emission tomography studies of dopamine-enhancing drugs SO JOURNAL OF CLINICAL PHARMACOLOGY LA English DT Article; Proceedings Paper CT Symposium on the Use of Imaging in Drug Research and Development CY SEP 11-13, 1998 CL NIH, BETHESDA, MARYLAND SP Soc Nucl Imaging Drug Dev HO NIH ID MONOAMINE-OXIDASE-B; BRAIN MAO-B; COCAINE; INHIBITION; METHYLPHENIDATE; TRANSPORTERS; RECEPTORS; SMOKERS C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. Columbia Univ, Dept Psychiat, New York, NY USA. RP Fowler, JS (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 19 TC 9 Z9 9 U1 2 U2 2 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0091-2700 J9 J CLIN PHARMACOL JI J. Clin. Pharmacol. PD AUG PY 1999 VL 39 SU S BP 13S EP 16S PG 4 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA 222RQ UT WOS:000081798900004 ER PT J AU de Vries, SA Goedtkindt, P Huisman, WJ Zwanenburg, MJ Feidenhans'l, R Bennett, SL Smilgies, DM Stierle, A De Yoreo, JJ van Enckevort, WJP Bennema, P Vlieg, E AF de Vries, SA Goedtkindt, P Huisman, WJ Zwanenburg, MJ Feidenhans'l, R Bennett, SL Smilgies, DM Stierle, A De Yoreo, JJ van Enckevort, WJP Bennema, P Vlieg, E TI X-ray diffraction studies of potassium dihydrogen phosphate (KDP) crystal surfaces SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE surface structure; X-ray diffraction; KDP; impurities; crystal growth ID HARTMAN-PERDOK THEORY; DISLOCATION CORES; GROWTH-MORPHOLOGY; PREDICTION; PERFORMANCE; VICINALITY; KH2PO4; DESIGN AB We have studied the surface atomic structure of KDP crystals using X-ray scattering. These crystals were grown from an aqueous solution and we have done measurements both ex situ and in situ, The ex situ measurements were performed in vacuum or in air. In order to be able to do in situ measurements, we designed and built a crystal growth chamber which is compatible with X-ray diffraction experiments. The atomic arrangement of the two naturally existing faces of KDP has been determined. Preliminary results are presented of measurements performed during growth, Furthermore, the influence of metal impurities on the atomic structure of the growing interface is examined, (C) 1999 Elsevier Science B.V. All rights reserved. C1 FOM, Inst Atom & Mol Phys, NL-1098 SJ Amsterdam, Netherlands. European Synchrotron Radiat Facil, F-38043 Grenoble, France. Riso Natl Lab, Dept Solid State Phys, DK-4000 Roskilde, Denmark. CCLRC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Nijmegen, RIM, Dept Solid State Chem, NL-6525 ED Nijmegen, Netherlands. RP Vlieg, E (reprint author), FOM, Inst Atom & Mol Phys, Kruislaan 407, NL-1098 SJ Amsterdam, Netherlands. RI van Enckevort, Willem/D-5226-2012; Vlieg, Elias/G-3386-2012; Goedtkindt, Peter/K-4458-2012; OI Goedtkindt, Peter/0000-0001-8572-6000; Smilgies, Detlef/0000-0001-9351-581X NR 32 TC 60 Z9 62 U1 1 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD AUG PY 1999 VL 205 IS 1-2 BP 202 EP 214 DI 10.1016/S0022-0248(99)00249-3 PG 13 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 225LA UT WOS:000081962000024 ER PT J AU Zaitseva, N Carman, L Smolsky, I Torres, R Yan, M AF Zaitseva, N Carman, L Smolsky, I Torres, R Yan, M TI The effect of impurities and supersaturation on the rapid growth of KDP crystals SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE rapid crystal growth; solution stability; impurity; dead zone; UV absorption ID NUCLEATION; KH2PO4; PHOSPHATE; KINETICS; IONS; ADP AB Potassium orthophosphate (KDP) crystals were grown at the growth rates from 0.5 to 25 mm/day. The distribution of impurities connected with the vicinal and sectoral structure of the rapidly grown crystals is described. It has been shown that to decrease the effect of impurities and to obtain crystals of high homogeneity, rapid growth should be performed at high supersaturations outside the dead zone and the region of the sharp increase of the growth rate with supersaturation. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Zaitseva, N (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 E Ave,POB 808, Livermore, CA 94550 USA. NR 24 TC 74 Z9 84 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD AUG 1 PY 1999 VL 204 IS 4 BP 512 EP 524 DI 10.1016/S0022-0248(99)00194-3 PG 13 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 220TH UT WOS:000081683200012 ER PT J AU Gunney, BTN Li, YA Olver, PJ AF Gunney, BTN Li, YA Olver, PJ TI Solitary waves in the critical surface-tension model SO JOURNAL OF ENGINEERING MATHEMATICS LA English DT Article DE solitary wave; surface tension; water wave; Korteweg-de Vries equation; Boussinesq expansion ID KORTEWEG-DEVRIES EQUATION; HOMOCLINIC ORBITS; WATER-WAVES; EXISTENCE; SOLITONS; 5TH-ORDER; SYSTEMS AB This paper studies the properties of solitary-wave solutions of a particular fifth-order evolution equation that models water waves with surface tension. Existence and nonexistence results are surveyed and strengthened. An accurate numerical code is devised and used to show the small dispersive effects of solitary-wave collisions. C1 Medtron Inc, Minneapolis, MN 55432 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Minnesota, Sch Math, Minneapolis, MN 55455 USA. RP Gunney, BTN (reprint author), Medtron Inc, 7000 Cent Ave NE, Minneapolis, MN 55432 USA. NR 38 TC 2 Z9 2 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-0833 J9 J ENG MATH JI J. Eng. Math. PD AUG PY 1999 VL 36 IS 1-2 BP 99 EP 112 DI 10.1023/A:1004593923334 PG 14 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 209GU UT WOS:000081040500007 ER PT J AU Maksimov, AA Pronin, DA Zaitsev, SV Tartakovskii, II Klein, MV Veal, BW AF Maksimov, AA Pronin, DA Zaitsev, SV Tartakovskii, II Klein, MV Veal, BW TI Effect of ordering of mobile oxygen on spectra of two-magnon and electronic Raman scattering of light in YBa2Cu3O6+x crystals with different doping levels SO JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; OFF-STOICHIOMETRIC YBA2CU3OZ; CU-O CHAINS; SINGLE-CRYSTALS; CHARGE-TRANSFER; DEPENDENCE; TRANSITION; MODEL; TC AB The effect of ordering of mobile chain-site oxygen in YBa2Cu3O6+x crystals at different doping levels x on the kinetics of the intensity change of the two-magnon line and the extended structureless electronic continuum in optical Raman spectra and on the superconducting transition temperature T-c, has been studied in detail. An increase in the chain-site oxygen content x leads to a higher contribution of free carriers to the electronic continuum in Raman spectra. The kinetics of the electronic continuum becomes slower with x, whereas the relaxation rate of the two-magnon scattering is a nonmonotonic function of the stoichiometric index. Computer simulations of the relaxation of nonequilibrium states using the Monte Carlo technique qualitatively describe the kinetics observed in experiments. Our results lead us to a conclusion about local inhomogeneities in the electronic and spin systems in CuO2 planes with scales of several lattice constants. (C) 1999 American Institute of Physics. [S1063-7761(99)02408-7]. C1 Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow Region, Russia. Univ Illinois, Sci & Technol Ctr Superconduct, Urbana, IL 61801 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Maksimov, AA (reprint author), Russian Acad Sci, Inst Solid State Phys, Chernogolovka 142432, Moscow Region, Russia. RI Maksimov, Andrei/C-5828-2017 NR 28 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 USA SN 1063-7761 J9 J EXP THEOR PHYS+ JI J. Exp. Theor. Phys. PD AUG PY 1999 VL 89 IS 2 BP 366 EP 376 DI 10.1134/1.558993 PG 11 WC Physics, Multidisciplinary SC Physics GA 235MY UT WOS:000082546500024 ER PT J AU Grappin, R Mangeney, A Schwartz, SJ Feldman, WC AF Grappin, R Mangeney, A Schwartz, SJ Feldman, WC TI Contribution of intermittent temperature peaks to the generation of the solar wind flow SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SONIC POINT; CONSTRAINTS; CORONA AB Observations of frequent, intermittent, density, velocity, and temperature variations, called jets, in the solar corona have led some authors to propose these jets as possible acceleration mechanisms for the fast solar wind seen at large distances. In the search of possible dynamical effects, we look here at the implications of intermittent temperature fluctuations at the coronal level on the subsonic and supersonic solar wind properties, in a spherically symmetric (single fluid) wind with polytropic index close to unity and no magnetic field. Sudden temperature pulses are applied periodically at the coronal level, with no pressure variation, the velocity being free. One finds that (1) the advected perturbations take the form of a mixture of upward propagating shock waves and advected pressure equilibrium structures and (2) the mean temperature increases due to the larger expansion rate of the fluid with peak temperature. As a result, a main part of the wind flow at large distance appears to be generated by intermittent coronal events with peak temperature. We propose thus to reduce the discrepancy between the fast wind speed observed at 1 AU and the observed coronal temperature by taking into account not the average temperature, but the peak coronal temperature, still to be determined. C1 Observ Paris, F-92195 Meudon, France. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse, France. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Queen Mary Univ London, Astron Unit, London E1 4NS, England. RP Grappin, R (reprint author), Observ Paris, F-92195 Meudon, France. EM grap-pin@melami.obspm.fr; mangeney@obspm.fr; S.J.Schwartz@wmw.ac.uk NR 17 TC 2 Z9 2 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD AUG 1 PY 1999 VL 104 IS A8 BP 17033 EP 17043 DI 10.1029/1999JA900181 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 222NB UT WOS:000081790700005 ER PT J AU Ezato, K Shehata, AM Kunugi, T McEligot, DM AF Ezato, K Shehata, AM Kunugi, T McEligot, DM TI Numerical prediction of transitional features of turbulent forced gas flows in circular tubes with strong heating SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT ASME Fluids Engineering Conference CY JUN, 1997 CL VANCOUVER, CANADA DE flow transition; forced convection; turbulence ID K-EPSILON MODEL; LAMINARIZATION; LAYER AB In order to treat strongly heated, forced gas flows at low Reynolds numbers in vertical circular tubes, the k-epsilon turbulence model of Abe, Kondoh, and Nagano (1994), developed for forced turbulent flow between parallel plates with the constant property idealization, has been successfully applied For thermal energy transport, the turbulent Prandtl number model of Kays and Crawford (1993) was adopted The capability to handle these flows was assessed via calculations at the conditions Of experiments by Shehata (1984), ranging from essentially turbulent to laminarizing due to the heating. Predictions forecast the development of turbulent transport quantities, Reynolds stress, and turbulent heat flux, as well as turbulent viscosity and turbulent kinetic energy. Overall agreement between the calculations and the measured velocity and temperature distributions is good, establishing confidence in the values of the forecast turbulence quantities-and the model which produced them. Most importantly, the model yields predictions which compare well with the measured wall hear transfer parameters and the pressure drop. C1 Kyushu Univ, Fukuoka 812, Japan. Japan Atom Energy Res Inst, Ibaraki, Osaka, Japan. Xerox Corp, Webster, NY 14580 USA. Kyoto Univ, Kyoto 606, Japan. Univ Arizona, Tucson, AZ USA. LMITCo, Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. RP Ezato, K (reprint author), Kyushu Univ, Fukuoka 812, Japan. NR 62 TC 19 Z9 19 U1 1 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD AUG PY 1999 VL 121 IS 3 BP 546 EP 555 DI 10.1115/1.2826015 PG 10 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 234YR UT WOS:000082512400004 ER PT J AU Wan, YP Prasad, V Wang, GX Sampath, S Fincke, JR AF Wan, YP Prasad, V Wang, GX Sampath, S Fincke, JR TI Model and powder particle heating, melting, resolidification, and evaporation in plasma spraying processes SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT IMECE 98 Meeting CY 1998 CL ANAHEIM, CALIFORNIA ID BINARY-ALLOYS; COMBUSTION; DYNAMICS; FLAME AB A comprehensive model is developed to study the heating, melting, evaporation, and resolidification of powder particles in plasma flames. The well-established LAVA code for plasma flame simulation is used to predict the plasma gas field under given power conditions, and provide inputs to the particle model. The particle is assumed to be a spherical and one-dimensional heat conduction equation with phase change within the particle is solved numerically using an appropriate coordinate transformation and finite difference method. Melting, vaporization, and resolidification interfaces are tracked and the particle vaporization is accounted for by the mass diffusion of vapor through the boundary layer around the particle. he effect of mass transfer on convective hear transfer is also included Calculations have been carried out for a single particle injected into an Ar-H, plasma jet, Zirconia and nickel are selected as solid particles because of their widespread industrial applications as well as significant differences in their thermal properties. Numerical results show strong nonisothermal effect of heating, especially for materials with low thermal conductivity, such as zirconia. The model also predicts strong evaporation of the material at high temperatures. C1 SUNY Stony Brook, Ctr Thermal Spray Res, Stony Brook, NY 11794 USA. SUNY Stony Brook, Proc Modeling Lab, Stony Brook, NY 11794 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Wan, YP (reprint author), SUNY Stony Brook, Ctr Thermal Spray Res, Stony Brook, NY 11794 USA. RI Wang, Guo-Xiang/E-6919-2014 NR 34 TC 68 Z9 69 U1 2 U2 25 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD AUG PY 1999 VL 121 IS 3 BP 691 EP 699 DI 10.1115/1.2826034 PG 9 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 234YR UT WOS:000082512400023 ER PT J AU Wang, ZL White, PS Petrovic, M Tatum, OL Newman, LS Maier, LA Marrone, BL AF Wang, ZL White, PS Petrovic, M Tatum, OL Newman, LS Maier, LA Marrone, BL TI Differential susceptibilities to chronic beryllium disease contributed by different Glu(69) HLA-DPB1 and-DPA1 alleles SO JOURNAL OF IMMUNOLOGY LA English DT Article ID LINKAGE DISEQUILIBRIUM; CAUCASOID POPULATION; NUCLEOTIDE-SEQUENCE; HLA; POLYMORPHISM; FREQUENCY; LOCI; DNA; IMMUNOGENETICS; AMPLIFICATION AB Chronic beryllium disease (CBD) is associated with the allelic substitution of a Glu(69) in the HLA-DPB1 gene, Although up to 97% of CBD patients may have the Glu(69) marker, about 30-45% of beryllium-exposed, unaffected individuals carry the same marker. Because CBD occurs in only 1-6% of exposed workers, the presence of Glu(69) does not appear to be the sole genetic factor underlying the disease development. Using two rounds of direct automated DNA sequencing to precisely assign HLA-DPB1 haplotypes, we have discovered highly significant Glu(69)-containing allele frequency differences between the CBD patients and a beryllium-exposed, nondiseased control group. Individuals with DPB1 Glu(69) in both alleles were almost exclusively found in the CBD group (6/20) vs the control group (1/75), Whereas most Glu(69) carriers from the control group had a DPB1 allele *0201 (68%), most Glu(69) carriers from the CBD group had a non-*0201 DPB1 Glu(69)-carrying allele (84%), The DPB1 allele *0201 was almost exclusively (29/30) associated with DPA1 *01 alleles, while the non-*0201 Glu(69)-containing DPB1 alleles were closely associated with DPA1 *02 alleles (26/29), Relatively rare Glu(69)-containing alleles *1701, *0901, and *1001 had extremely high frequencies in the CBD group (50%), as compared,vith the control group (6.7%). Therefore, the most common Glu(69)-containing DPB1 allele, *0201, does not seem to be a major disease allele, The results suggest that it is not the mere presence of Glu(69), per se, but specific Glu(69)-containing alleles and their copy number (homozygous or;heterozygous) that confer the greatest susceptibility to CBD in exposed individuals. C1 Univ Calif Los Alamos Natl Lab, Div Life Sci, Los Alamos, NM 87545 USA. Natl Jewish Med & Res Ctr, Denver, CO USA. Univ Colorado, Hlth Sci Ctr, Denver, CO USA. RP Marrone, BL (reprint author), Univ Calif Los Alamos Natl Lab, Div Life Sci, LS-5,M888, Los Alamos, NM 87545 USA. NR 31 TC 95 Z9 97 U1 2 U2 4 PU AMER ASSOC IMMUNOLOGISTS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0022-1767 J9 J IMMUNOL JI J. Immunol. PD AUG 1 PY 1999 VL 163 IS 3 BP 1647 EP 1653 PG 7 WC Immunology SC Immunology GA 219ZX UT WOS:000081640000070 PM 10415070 ER PT J AU Fu, H Trouw, F Sokol, PE AF Fu, H Trouw, F Sokol, PE TI A quasi-elastic and inelastic neutron scattering study of H-2 in zeolite SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article ID POROUS VYCOR GLASS; MOLECULAR-HYDROGEN; LIQUID-HYDROGEN; GEOMETRIES AB The diffusion of molecular hydrogen adsorbed in zeolite 13X at high coverage's has been studied by quasi-elastic neutron scattering Sor temperatures ranging from 0 to 60 K, No diffusive morion was observed, within instrumental resolution, at temperatures below 20 K, well above the bulk melting point of H-2, in contrast to recent NMR studies. The diffusive motion of the adsorbed H-2 could be described by a liquid like jump diffusion model above 35 K. The diffusion coefficient demonstrates an Arrhenius behavior. D = D-0 exp(E/kT), with D-0 = 1.2 x 10(-8) m(2)/s and an activation energy of E = 62 K. The inelastic scattering spectrum has also been studied. The scattering consisted of several peaks superimposed on a broad background extending from 1 meV to above 100 meV mid is consistent with rotational transitions for a hindered rotor in a strong orientational potential with a broad distribution of barrier heights. C1 Penn State Univ, Dept Phys, University Pk, PA 16801 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Keele, Dept Phys, Keele ST5 5BG, Staffs, England. RP Fu, H (reprint author), Penn State Univ, Dept Phys, University Pk, PA 16801 USA. NR 29 TC 19 Z9 19 U1 0 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD AUG PY 1999 VL 116 IS 3-4 BP 149 EP 165 DI 10.1023/A:1021881516198 PG 17 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 230DG UT WOS:000082236100001 ER PT J AU Batlle, X Echer, C Krishnan, KM Hattink, BJ Labarta, A AF Batlle, X Echer, C Krishnan, KM Hattink, BJ Labarta, A TI Structural and magnetic properties of iron particles in a copper matrix SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Conference on Magnetism of Nanostructured Phases (NMNP) CY SEP 04-06, 1998 CL SAN SEBASTIAN, SPAIN SP European Phys Soc, Dept Fisica Aplicada, Escuela Univ Ingenieria Tecbica Ind, Avda Felipe, Dept Educ, Univ Invest Gobierno Vaso, Dept Fisica Mat Fac Quimica, P Manuel Lardizabal, Minist Educ Cultura, Vicerrectorado Campus Guipuzcoa UPV, EHU, Excma Diputacion Foral Guipuzcoa, Excma Ayuntamiento San Sebastian, Grupo Magnetismo Campus Guipuzoca UPV,EHU, 17 Summer Courses DE phase segregation; antiferromagnetic correlations; spin glass-like behavior ID GIANT MAGNETORESISTANCE AB The structural and magnetic properties of Fe particles grown in a Cu matrix by annealing a precursor alloy of composition Cu97Fe3 are discussed. Structural characterization suggests that all segregated Fe particles are BCC-type. However, AC susceptibility and hysteresis loops display short-range antiferromagnetic correlations and a spin glass-like behavior. The former is analyzed in terms of the effects occurring at the particle surface, while the latter is associated with the Fe spins diluted in the Cu matrix. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Lab, NCEM, Berkeley, CA 94720 USA. Univ Barcelona, Fac Fis, Dept Fis Fonamental, Barcelona 08028, Catalonia, Spain. RP Batlle, X (reprint author), Lawrence Berkeley Lab, NCEM, Berkeley, CA 94720 USA. RI Labarta, Amilcar/B-4539-2012; Batlle, Xavier/H-5795-2012 OI Labarta, Amilcar/0000-0003-0904-4678; NR 5 TC 1 Z9 1 U1 1 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 AUG PY 1999 VL 203 SI SI BP 120 EP 122 DI 10.1016/S0304-8853(99)00208-5 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 221EB UT WOS:000081710100036 ER PT J AU Prokes, K Svoboda, P Kolomiets, A Sechovsky, V Nakotte, H de Boer, FR Winand, JM Rebizant, J Spirlet, JC AF Prokes, K Svoboda, P Kolomiets, A Sechovsky, V Nakotte, H de Boer, FR Winand, JM Rebizant, J Spirlet, JC TI Magnetic structure of U2Pt2Sn SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE magnetic structure; actinides; antiferromagnetism; hybridization ID U(2)T(2)X COMPOUNDS; ELECTRONIC-PROPERTIES; CRYSTAL-STRUCTURE; RH AB U2Pt2Sn forms in a ternary derivative version (space group P4(2)/mnm) of the tetragonal U3Si2-type of structure. Clear anomalies in the magnetic susceptibility, specific heat and electrical resistivity around 15 K and their changes in magnetic fields indicate antiferromagnetic ordering below this temperature. The antiferromagnetic ground state of U2Pt2Sn is corroborated by the metamagnetic transition observed in the magnetization around 22 T measured at 4.2 K and by magnetic reflections in the neutron-powder diffraction pattern at low temperatures. The U moments of 1.16 +/- 0.07 mu(B)/U form a complex incommensurate non-collinear magnetic structure. The moments are confined to (1 1 0)-type of planes and tilted from the c-axis by 60 degrees. Moreover they are sine-wave modulated along the tetragonal axis with a propagation vector q = (0, 0, 0.1823). (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 Hiroshima Univ, ADSM, Dept Quantum Matter, Higashihiroshima 7398526, Japan. Charles Univ, Dept Elect Struct, Prague 12116 2, Czech Republic. New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA. Univ Amsterdam, Van der Waals Zeeman Inst, NL-1018 XE Amsterdam, Netherlands. Commiss European Communities, Joint Res Ctr, Inst Transuranium Elements, D-76125 Karlsruhe, Germany. Univ Calif Los Alamos Natl Lab, LANSCE, MLNSC, Los Alamos, NM 87545 USA. RP Prokes, K (reprint author), Hahn Meitner Inst Kernforsch Berlin GmbH, BENSC, Abt NE, Glienicker Str 100, D-14195 Berlin, Germany. RI Sechovsky, Vladimir/A-5256-2008 OI Sechovsky, Vladimir/0000-0003-1298-2120 NR 21 TC 6 Z9 6 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD AUG PY 1999 VL 202 IS 2-3 BP 451 EP 457 DI 10.1016/S0304-8853(99)00370-4 PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 220TK UT WOS:000081683400023 ER PT J AU Boone, JL Smith, MH Laerm, J AF Boone, JL Smith, MH Laerm, J TI Allozyme variation in the cotton mouse (Peromyscus gossypinus) SO JOURNAL OF MAMMALOGY LA English DT Article DE Peromyscus gossypinus; cotton mice; genetics; allozyme variation AB We examined allozyme variation at 40 presumptive gene loci in 1,904 cotton mice (Peromyscus gossypinus) from 62 locations throughout the range of the species. This species was highly variable: 92.7 percent of loci were polymorphic, observed heterozygosity per population ranged from 0.023 to 0.123 and averaged 0.088, and number of alleles per polymorphic locus averaged 5.6. The least variable populations were from the western part of the range, and the most variable were from the southeastern part. Virtually every population contained unique or rare alleles. Distribution of allozyme variation generally reflected geographic proximity rather than existing subspecies boundaries, with major differences between western, northeastern, southeastern, and insular populations. The most divergent populations were from Georgia and Florida sea islands, but drift alone could not explain this observation, because the largest number of unique alleles per population also occurred in these populations. C1 Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ Georgia, Inst Ecol, Athens, GA 30602 USA. Univ Georgia, Museum Hist Nat, Athens, GA 30602 USA. Univ Georgia, Dept Zool, Athens, GA 30602 USA. Univ Georgia, Dept Ecol, Athens, GA 30602 USA. Univ Georgia, Dept Genet, Athens, GA 30602 USA. Univ Georgia, Sch Forest Resources, Athens, GA 30602 USA. RP Boone, JL (reprint author), Sci Applicat Int Corp, 1261 Town Ctr Dr, Las Vegas, NV 89134 USA. NR 29 TC 1 Z9 1 U1 0 U2 1 PU AMER SOC MAMMALOGISTS PI PROVO PA BRIGHAM YOUNG UNIV, DEPT OF ZOOLOGY, PROVO, UT 84602 USA SN 0022-2372 J9 J MAMMAL JI J. Mammal. PD AUG PY 1999 VL 80 IS 3 BP 833 EP 844 DI 10.2307/1383252 PG 12 WC Zoology SC Zoology GA 233UC UT WOS:000082444800013 ER PT J AU Melkote, SN Sutherland, JW King, C AF Melkote, SN Sutherland, JW King, C TI The effect of tool flexibility on back-cutting in end milled surfaces SO JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID FORCE; GENERATION AB End milled surface texture is inhomogeneous and often exhibits complex lay patterns. An important contributing factor to these surface characteristics is the back-cutting effect. This effect causes cutter tooth mark patterns on the surface in the forward and reverse tool feed directions. In this paper, the dependence of back-cutting on end mill flexibility and its influence on the slot floor surface texture are modeled and experimentally verified. It is shown that the extent to which tool flexibility affects back-cutting is determined by the resultant cutting force system and not the feed force alone. The variation in the amount of back-cutting typically observed across the width of a milled slot is also explained by this model. The model, although simple in form, yields reasonably good agreement with the measured surface profiles. C1 Georgia Inst Technol, George W Woodruff Sch Mech Engn, Atlanta, GA 30332 USA. Michigan Technol Univ, Dept Mech Engn & Engn Mech, Houghton, MI 49931 USA. Sandia Natl Labs, Informat Syst Engn Ctr, Albuquerque, NM 87185 USA. RP Melkote, SN (reprint author), Georgia Inst Technol, George W Woodruff Sch Mech Engn, Atlanta, GA 30332 USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1087-1357 J9 J MANUF SCI E-T ASME JI J. Manuf. Sci. Eng.-Trans. ASME PD AUG PY 1999 VL 121 IS 3 BP 532 EP 537 DI 10.1115/1.2832713 PG 6 WC Engineering, Manufacturing; Engineering, Mechanical SC Engineering GA 230EG UT WOS:000082238400030 ER PT J AU Pinhero, PJ Anderegg, JW Sordelet, DJ Lograsso, TA Delaney, DW Thiel, PA AF Pinhero, PJ Anderegg, JW Sordelet, DJ Lograsso, TA Delaney, DW Thiel, PA TI Surface oxidation of a quasicrystalline Al-Cu-Fe alloy: No effect of surface orientation and grain boundaries on the final state SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID QUASI-CRYSTALLINE COATINGS; HYDROGEN STORAGE; PHASE; ADSORPTION; AES AB We have used x-ray photoelectron spectroscopy and Auger electron spectroscopy to examine the characteristics of oxides on two types of quasicrystalline Al-Cu-Fe samples. One type was formed by consolidation of powders, resulting in multiple grains with random surface orientations. The other was a single grain, oriented to expose a fivefold surface. Both were oxidized to saturation in a variety of environments at room temperature. We measured the elemental constituents that oxidized, the extent of oxygen-induced Al segregation, and the depth of the oxide. Under the conditions of our experiments, there was little, if any, significant difference between the two types of samples. Hence, surface orientation and bulk microstructure played little or no role on the final state of the oxide under these conditions. C1 Iowa State Univ Sci & Technol, Ames Lab, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Mech Engn, Ames, IA 50011 USA. RP Thiel, PA (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Dept Mat Sci & Engn, Ames, IA 50011 USA. NR 42 TC 16 Z9 17 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD AUG PY 1999 VL 14 IS 8 BP 3185 EP 3188 DI 10.1557/JMR.1999.0427 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 235PG UT WOS:000082550800002 ER PT J AU Fitz-Gerald, JM Singh, RK Gao, H Wright, D Ollinger, M Marcinka, JW Pennycook, SJ AF Fitz-Gerald, JM Singh, RK Gao, H Wright, D Ollinger, M Marcinka, JW Pennycook, SJ TI Novel method for the synthesis of thin film coatings on particulate materials SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID LASER ABLATION; YBA2CU3O7-X; GROWTH AB In this paper, we show the feasibility of the pulsed-laser ablation technique to grow 20-30-nm-thick, discrete and continuous coatings on particulate material systems so that the properties of the core particles can be suitably modified. Experiments were conducted with a pulsed excimer laser (lambda = 248 nm, pulse duration = 25 ns) to deposit nanoparticle coatings on Al2O3 and SiO2 core particles by irradiation of Ag and Y2O3-Eu3+ sputtering targets. Structural characterization was performed with scanning electron microscopy, wavelength dispersive x-ray mapping, transmission electron microscopy, and scanning transmission electron microscopy with z-contrast. C1 USN, Res Lab, Washington, DC 20375 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Florida Atlantic Univ, Dept Elect Engn, Boca Raton, FL 33431 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP USN, Res Lab, Code 6372, Washington, DC 20375 USA. NR 32 TC 9 Z9 9 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD AUG PY 1999 VL 14 IS 8 BP 3281 EP 3291 DI 10.1557/JMR.1999.0444 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA 235PG UT WOS:000082550800019 ER PT J AU Chien, AT Sachleben, J Kim, JH Speck, JS Lange, FF AF Chien, AT Sachleben, J Kim, JH Speck, JS Lange, FF TI Synthesis and characterization of PbTiO3 powders and heteroepitaxial thin films by hydrothermal synthesis SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID LEAD-ZIRCONATE-TITANATE; EPITAXIAL-GROWTH; CRYSTAL-GROWTH; SURFACE; BATIO3; DISSOLUTION; CERAMICS; QUARTZ AB PbTiO3 powders and heteroepitaxial thin films were produced by the hydrothermal method at 110-200 degrees C using different bases (Na-, K-, Rb-, Cs-, TMA-, and TEA-OH). Microstructural characterization showed that the tetragonal perovskite films were epitaxial on the SrTiO3 substrates, with a c-axis out-of-plane orientation. Sequential growth experiments showed that the growth initiates by the formation of 100 nm {100} faceted PbTiO3 islands followed by coalescence. Small cation bases (Na-, K-, Rb-OH) produced 1.5-mu m {100} faceted blocky powders, whereas larger cation bases (Cs-, TMA-., and TEA-OH) formed fewer 500-nm interpenetrating platelets. Nuclear magnetic resonance results showed cation incorporation in the perovskite structure with local disorder on the Pb sites increasing cation size. C1 Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Mat Res Lab, Santa Barbara, CA 93106 USA. RP Chien, AT (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-370, Livermore, CA 94551 USA. RI Speck, James/H-5646-2011 NR 36 TC 42 Z9 42 U1 1 U2 9 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD AUG PY 1999 VL 14 IS 8 BP 3303 EP 3311 DI 10.1557/JMR.1999.0447 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 235PG UT WOS:000082550800022 ER PT J AU Chien, AT Xu, X Kim, JH Sachleben, J Speck, JS Lange, FF AF Chien, AT Xu, X Kim, JH Sachleben, J Speck, JS Lange, FF TI Electrical characterization of BaTiO3 heteroepitaxial thin films by hydrothermal synthesis SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID BARIUM-TITANATE; GROWTH; POWDERS; SRTIO3 AB The electrical properties of hydrothermally grown epitaxial pseudocubic BaTiO3 thin films formed on epitaxial electrode layers of SrRuO3 on SrTiO3 single crystal substrates have been evaluated by variable frequency dielectric testing. The initial as-synthesized BaTiO3 film displayed a dielectric constant of 450 with very high losses (tan delta similar to 100%) at 10 kHz due to OH- and H2O, incorporated during growth, contributing to migration losses within the film. Improvements were seen with increasing postprocessing heat-treatment time and temperature with improved properties seen after a heat treatment at 300 degrees C for 24 h (epsilon similar to 200, tan delta similar to 8%). Relationships were established for dielectric constant and loss tangent with structural changes observed by Fourier transform infrared spectroscopy, thermal gravimetric analysis, nuclear magnetic resonance spectroscopy, and x-ray diffraction. C1 Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Mat Res Lab, Santa Barbara, CA 93106 USA. RP Chien, AT (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-370, Livermore, CA 94551 USA. RI Speck, James/H-5646-2011 NR 31 TC 78 Z9 78 U1 1 U2 14 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD AUG PY 1999 VL 14 IS 8 BP 3330 EP 3339 DI 10.1557/JMR.1999.0451 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 235PG UT WOS:000082550800026 ER PT J AU Ma, XD Unertl, WN Erdemir, A AF Ma, XD Unertl, WN Erdemir, A TI The boron oxide-boric acid system: Nanoscale mechanical and wear properties SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID TRIBOLOGICAL PROPERTIES; FORCE MICROSCOPE; FORMING SURFACES; SELF-LUBRICATION; ELASTIC-MODULUS; FILMS; INDENTATION; FRICTION; BEHAVIOR; DENSITY AB The film that forms spontaneously when boron oxide (B(2)O(3)) is exposed to humid air is a solid lubricant. This film is usually assumed to be boric acid (H(3)BO(3)), the stable bulk phase. We describe the nanometer-scale surface morphology, mechanical properties, and tribological properties of these films and compare them with crystals precipitated from saturated solutions of boric acid. Scanning force microscopy (SFM) and low-load indentation were the primary experimental tools. Mechanical properties and their Variation with depth are reported. In all cases, the surfaces were covered with a layer that has different mechanical properties than the underlying bulk. The films formed on boron oxide showed no evidence of crystalline structure. A thin surface layer was rapidly removed, followed by slower wear of the underlying film. The thickness of this initial layer was sensitive to sample preparation conditions, including humidity. Friction on the worn surface was lower than on the as-formed surface in all cases. In contrast, the SFM tip was unable to cause any wear to the surface film on the precipitated crystals. Indentation pop-in features were common for precipitated crystals but did not occur on the films formed on boron oxide. The surface structures were more complex than assumed in models put forth previously to explain the mechanism of lubricity in the boron oxide-boric acid-water system. C1 Univ Maine, Surface Sci & Technol Lab, Orono, ME 04469 USA. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. China Univ Mining & Technol, Beijing 100083, Peoples R China. RP Unertl, WN (reprint author), Univ Maine, Surface Sci & Technol Lab, Orono, ME 04469 USA. EM unertl@maine.edu NR 30 TC 20 Z9 20 U1 3 U2 11 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD AUG PY 1999 VL 14 IS 8 BP 3455 EP 3466 DI 10.1557/JMR.1999.0467 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA 235PG UT WOS:000082550800042 ER PT J AU Dong, HL Onstott, TC DeFlaun, MF Fuller, ME Gillespie, KM Fredrickson, JK AF Dong, HL Onstott, TC DeFlaun, MF Fuller, ME Gillespie, KM Fredrickson, JK TI Development of radiographic and microscopic techniques for the characterization of bacterial transport in intact sediment cores from Oyster, Virginia SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE bacterial retention; breakthrough; filtration; microscopic; phosphor imaging ID REDUCTION AB The objective of this study was to ascertain the physical and mineralogical properties responsible for the retention of bacteria in subsurface sediments. The sediment core chosen for this study was a fine-grained, quartz-rich sand with minor amounts of Fe and Al hydroxides, A bacterial transport experiment was performed using an intact core collected from a recent excavation of the Butler's Bluff member of the Nassawadox formation in the borrow pit at Oyster, VA. and a C-14-labeled bacterial strain OYS2-A was selected for its relatively low adhesion. After the bacterial breakthrough was observed in the effluent, the intact core was dissected to determine the internal distribution of the injected bacteria retained in the sediment. The sediment was dried, epoxy fixed, and thin sectioned. The distribution of C-14 activity in the thin sections was mapped using a phosphor screen and X-ray film. The remainder of the core was subsampled and the C-14 activity of the subsamples was determined by Liquid scintillation counting. The phosphor imaging technique was capable of directly imaging the distribution of radiolabeled bacteria in thin sections, because of its high sensitivity and linear response over a large activity range. The phosphor imaging signal intensity was utilized as a measure of bacterial concentration. The distribution of bacteria at the millimeter scale in the thin sections was compared to the grain size, porosity, and mineralogy as measured by scanning electron microscopy (SEM) and energy dispersive spectrum (EDS) analyses. No apparent correlation was observed between the retention or collision efficiency of bacteria in the sediment and the amount of Fe and Al hydroxides. This apparent lack of correlation can be qualitatively explained by combination of several factors including a nearly neutral surface charge of the bacterial strain, and texture of the Fe and Al hydroxides in the sediment. The combination of phosphor imaging with SEM-EDS proved to be a robust method for relating the physical and mineralogical microscopic properties of poorly indurated sediment to the distribution of adsorbed bacteria, allowing bacterial retention mechanisms to be unambiguously unraveled. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. Envirogen Inc, Princeton Res Ctr, Lawrenceville, NJ 08648 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Dong, HL (reprint author), Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. NR 14 TC 10 Z9 10 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-7012 J9 J MICROBIOL METH JI J. Microbiol. Methods PD AUG PY 1999 VL 37 IS 2 BP 139 EP 154 DI 10.1016/S0167-7012(99)00056-1 PG 16 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA 220VB UT WOS:000081687200004 PM 10445313 ER PT J AU Walensky, LD Blackshaw, S Liao, DZ Watkins, CC Weier, HUG Parra, M Huganir, RL Conboy, JG Mohandas, N Snyder, SH AF Walensky, LD Blackshaw, S Liao, DZ Watkins, CC Weier, HUG Parra, M Huganir, RL Conboy, JG Mohandas, N Snyder, SH TI A novel neuron-enriched homolog of the erythrocyte membrane cytoskeletal protein 4.1 SO JOURNAL OF NEUROSCIENCE LA English DT Article DE protein 4.1; neuron; red blood cell; cytoskeleton; synapse; ankyrin ID GLYCOPHORIN-C; ANKYRIN GENE; HIPPOCAMPAL-NEURONS; SKELETAL PROTEINS; BINDING-PROTEIN; BETA-SPECTRIN; MICE LACKING; CELLS; ISOFORMS; EXPRESSION AB We report the molecular cloning and characterization of 4.1N, a novel neuronal homolog of the erythrocyte membrane cytoskeletal protein 4.1 (4.1R). The 879 amino acid protein shares 70, 36, and 46% identity with 4.1R in the defined membrane-binding, spectrin-actin-binding, and C-terminal domains, respectively. 4.1N is expressed in almost all central and peripheral neurons of the body and is detected in embryonic neurons at the earliest stage of postmitotic differentiation. Like 4.1R, 4.1N has multiple splice forms as evidenced by PCR and Western analysis. Whereas the predominant 4.1N isoform identified in brain is similar to 135 kDa, a smaller 100 kDa isoform is enriched in peripheral tissues. Immunohistochemical studies using a polyclonal 4.1N antibody revealed several patterns of neuronal staining, with localizations in the neuronal cell body, dendrites, and axons. In certain neuronal locations, including the granule cell layers of the cerebellum and dentate gyrus, a distinct punctate-staining pattern was observed consistent with a synaptic localization. In primary hippocampal cultures, mouse 4.1N is enriched at the discrete sites of synaptic contact, colocalizing with the postsynaptic density protein of 95 kDa (a postsynaptic marker) and glutamate receptor type 1 (an excitatory postsynaptic marker). By analogy with the roles of 4.1R in red blood cells, 4.1N may function to confer stability and plasticity to the neuronal membrane via interactions with multiple binding partners, including the spectrin-actin-based cytoskeleton, integral membrane channels and receptors, and membrane-associated guanylate kinases. C1 Johns Hopkins Univ, Sch Med, Dept Neurosci, Baltimore, MD 21205 USA. Johns Hopkins Univ, Sch Med, Dept Pharmacol & Mol Sci, Baltimore, MD 21205 USA. Johns Hopkins Univ, Sch Med, Dept Psychiat, Baltimore, MD 21205 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Snyder, SH (reprint author), Johns Hopkins Univ, Sch Med, Dept Neurosci, 813 Wood Basic Sci Bldg,725 N Wolfe St, Baltimore, MD 21205 USA. FU NIDA NIH HHS [DA-00074]; NIGMS NIH HHS [GM-07309]; NIMH NIH HHS [F30 MH012545, MH-18501] NR 56 TC 108 Z9 110 U1 0 U2 1 PU SOC NEUROSCIENCE PI WASHINGTON PA 11 DUPONT CIRCLE, NW, STE 500, WASHINGTON, DC 20036 USA SN 0270-6474 J9 J NEUROSCI JI J. Neurosci. PD AUG 1 PY 1999 VL 19 IS 15 BP 6457 EP 6467 PG 11 WC Neurosciences SC Neurosciences & Neurology GA 220DC UT WOS:000081648400024 PM 10414974 ER PT J AU Murtagh, MT Sigel, GH Fajardo, JC Edwards, BC Epstein, RI AF Murtagh, MT Sigel, GH Fajardo, JC Edwards, BC Epstein, RI TI Laser-induced fluorescent cooling of rare-earth-doped fluoride glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 18th International Congress of Glass CY JUL 05-10, 1998 CL SAN FRANCISCO, CALIFORNIA ID ABLATION AB Continual cooling of a material by anti-Stokes luminescence has been experimentally observed in a solid material. Net cooling was achieved by pumping to the lower levels of the F-2(5/2) manifold of Yb3+ followed by population redistribution across this manifold via thermalization and fluorescence to the ground state, Fluoride glass hosts in the ZBLAN and BaF2-InF3-GaF3 (BIG) families have been used in these experiments. Temperature decreases of 0.33 K in a bulk glass sample and 16 K in a fiber sample were obtained in ZBLANPb:Yb3+. Net cooling was achieved when an electrochemical purification stage was incorporated into the glass fabrication process to decrease the extrinsic absorptive component of the host glass in the 1.0 mu m region. Resonant laser ablation experiments showed the positive and negative effects of electrochemical processing on fluoride glasses in reducing transition metal content which is detrimental to successful fluorescent cooling. Reduction in copper, iron, and chromium content of 18, 4.2, and 5.5 were determined for the ZBLANPb sample via RLA. However, reductions in transition metal content were only 1.9 for copper and a negligible amount for iron and chromium in the BIG glasses, (C) 1999 Elsevier Science B.V. All rights reserved. C1 Rutgers State Univ, Fiber Opt Mat Res Program, Piscataway, NJ 08854 USA. Corning Inc, Sci & Technol, Corning, NY 14831 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Murtagh, MT (reprint author), Rutgers State Univ, Fiber Opt Mat Res Program, 607 Taylor Rd, Piscataway, NJ 08854 USA. NR 26 TC 14 Z9 15 U1 0 U2 4 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 AUG PY 1999 VL 253 BP 50 EP 57 DI 10.1016/S0022-3093(99)00405-6 PG 8 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 231EH UT WOS:000082294800006 ER PT J AU Holland, D Mekki, A Gee, IA McConville, CF Johnson, JA Johnson, CE Appleyard, P Thomas, M AF Holland, D Mekki, A Gee, IA McConville, CF Johnson, JA Johnson, CE Appleyard, P Thomas, M TI The structure of sodium iron silicate glass - a multi-technique approach SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 18th International Congress of Glass CY JUL 05-10, 1998 CL SAN FRANCISCO, CALIFORNIA ID FE-57 MOSSBAUER-SPECTROSCOPY AB Sodium iron silicate glasses of formula 0.3Na(2)O . xFe(2)O(3).(0.7-x)SiO2 (0.0 less than or equal to x less than or equal to 0.20) have been prepared by melt-quenching and their structures have been studied using X-ray photoelectron spectroscopy (XPS), neutron diffraction and Mossbauer spectroscopy. XPS of surfaces fractured in ultra-high vacuum showed the presence of both Fe2+ and Fe3+ in the glasses but the proportion of the smaller oxidation state is <20% for larger x. The O 1s spectrum can be fitted by bridging and non-bridging oxygen contributions but properties show that this description is inadequate and there are contributions from bridging oxygens, Si-O-Si, from non-bridging oxygens, Si-O Na+ and also directionally bonded Si-O-Fe. The neutron diffraction and Mossbauer data indicate that iron, irrespective of oxidation state, is 4-coordinated by oxygen. The Fe-O bond length decreases and the O-O bond length increases with increasing Fe2O3 content. Mossbauer spectroscopy confirms the predominance of the Fe3+ state in these glasses and indicates smaller Fe2+ concentrations than does XPS. possibly due to restructuring at the glass fracture surfaces examined in XPS, The effective Debye temperatures for Fe2+ and Fe3+ are 258 and 312 K, respectively, a consequence of the different M-O bond strengths of the two oxidation states. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Argonne Natl Lab, Argonne, IL 60439 USA. Liverpool John Moores Univ, Dept Built Environm, Liverpool L3 5UX, Merseyside, England. Univ Liverpool, Dept Phys, Liverpool L69 3BX, Merseyside, England. RP Holland, D (reprint author), Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. RI Johnson, Jacqueliine/G-7365-2011; Johnson, Jacqueline/P-4844-2014 OI Johnson, Jacqueline/0000-0003-0830-9275 NR 20 TC 42 Z9 42 U1 2 U2 20 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 AUG PY 1999 VL 253 BP 192 EP 202 DI 10.1016/S0022-3093(99)00353-1 PG 11 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 231EH UT WOS:000082294800020 ER PT J AU Pilgrim, WC Hosokawa, S Saggau, H Ross, M Yang, LH AF Pilgrim, WC Hosokawa, S Saggau, H Ross, M Yang, LH TI Molecular aggregation in expanded liquid rubidium SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 10th International Conference on Liquid and Amorphous Metal (LAM-10) CY AUG 30-SEP 04, 1998 CL UNIV DORTMUND, DORTMUND, GERMANY HO UNIV DORTMUND ID DYNAMIC STRUCTURE FACTOR; MAGNETIC-SUSCEPTIBILITY; TRANSITION; METALS; CESIUM; VAPOR AB An investigation on the density dependence of the dynamic structure factor, S(Q,omega), for liquid rubidium was performed by inelastic neutron scattering experiments for a variety of conditions along the vapor pressure curve. Down to densities of about three times the critical density we found that the dynamics are still controlled by the metallic properties of the system. At higher temperatures and pressures and corresponding lower densities a deviation from these properties is found: at about twice the critical density S(Q,omega) is affected by molecular excitations. The effects of the excitations continue to even higher temperatures and lower densities. The interpretation of molecular excitations is qualitatively in accord with a simple model in which the total energy of Rb-lattices at 0 K is calculated from first principles. The agreement between theoretical and experimental results provides evidence for the appearance of molecules or clusters in expanded liquid alkali metals. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Marburg, Inst Phys Chem Nucl Chem & Macromol Chem, D-35032 Marburg, Germany. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Pilgrim, WC (reprint author), Univ Marburg, Inst Phys Chem Nucl Chem & Macromol Chem, D-35032 Marburg, Germany. NR 21 TC 7 Z9 7 U1 0 U2 1 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 AUG PY 1999 VL 250 BP 154 EP 158 DI 10.1016/S0022-3093(99)00113-1 PN 1 PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 231ED UT WOS:000082294400031 ER PT J AU Tostmann, H DiMasi, E Ocko, BM Deutsch, M Pershan, PS AF Tostmann, H DiMasi, E Ocko, BM Deutsch, M Pershan, PS TI X-ray studies of liquid metal surfaces SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 10th International Conference on Liquid and Amorphous Metal (LAM-10) CY AUG 30-SEP 04, 1998 CL UNIV DORTMUND, DORTMUND, GERMANY HO UNIV DORTMUND ID REFLECTIVITY; GALLIUM; ALLOYS; FILMS AB X-ray reflectivity and diffuse scattering measurements of the surface of liquid Hg, Ga and In are reviewed. For each metal surface induced layering is found. The surface structure of these metals is compared and differences are discussed in relation to bulk structural features such as the degree of covalency. Studies of modified liquid metal surfaces are also presented. The surface oxidation of liquid Ga, In and Hg is compared. Experimental results on surface segregation in Ga-In and Ga-Bi alloys and details of the surface wetting transition in Ga-Bi are also discussed. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Bar Ilan Univ, Dept Phys, IL-52900 Ramat Gan, Israel. RP Pershan, PS (reprint author), Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. NR 33 TC 15 Z9 15 U1 0 U2 8 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 AUG PY 1999 VL 250 BP 182 EP 190 DI 10.1016/S0022-3093(99)00226-4 PN 1 PG 9 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 231ED UT WOS:000082294400037 ER PT J AU Krishnan, S Ansell, S Price, DL AF Krishnan, S Ansell, S Price, DL TI X-ray diffraction on levitated liquids: application to liquid 80%Co-20%Pd alloy SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 10th International Conference on Liquid and Amorphous Metal (LAM-10) CY AUG 30-SEP 04, 1998 CL UNIV DORTMUND, DORTMUND, GERMANY HO UNIV DORTMUND ID SYNCHROTRON-RADIATION; HIGH-TEMPERATURE; MELTS; OXIDE; METAL AB We describe the use of a novel levitation apparatus for structural studies on liquid materials using synchrotron X-ray scattering. The apparatus has been employed in investigations of the structural properties of a range of liquid ceramic, metallic, and semiconducting materials in the temperature range of 1000-3500 K. The apparatus uses conical nozzle levitation to stably position solid and liquid specimens at temperatures >1000 K. Specimens are heated with a 270 W, CO2 laser to melt, overheat and supercool the specimens in the desired temperature range. We report the first measurements of the total structure factor, S(Q), and pair distributions function, G(r), of liquid 80%Co-20%Pd in both the normal and supercooled states. This alloy has been previously reported to exhibit magnetic order in the supercooled Liquid state. No abrupt structural change was observed as the alloy was supercooled, although it was not possible to cool the liquid to temperatures at which magnetic ordering has been reported. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Containerless Res Inc, Evanston, IL 60201 USA. Argonne Natl Lab, Argonne, IL 60349 USA. RP Krishnan, S (reprint author), Containerless Res Inc, 906 Univ Pl, Evanston, IL 60201 USA. RI Price, David Long/A-8468-2013 NR 17 TC 11 Z9 11 U1 0 U2 4 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 AUG PY 1999 VL 250 BP 286 EP 292 DI 10.1016/S0022-3093(99)00251-3 PN 1 PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 231ED UT WOS:000082294400056 ER PT J AU Barnes, AC Hamilton, MA Buchanan, P Saboungi, ML AF Barnes, AC Hamilton, MA Buchanan, P Saboungi, ML TI Combined X-ray and neutron diffraction from binary liquids and amorphous semiconductors SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 10th International Conference on Liquid and Amorphous Metal (LAM-10) CY AUG 30-SEP 04, 1998 CL UNIV DORTMUND, DORTMUND, GERMANY HO UNIV DORTMUND ID SUBSTITUTION; SCATTERING; CHLORIDE AB Neutron scattering and isotopic substitution has been established as a method of unambiguously determining the partial structure factors of binary liquid and amorphous materials. In this paper we present results of an extension of this method to include X-ray diffraction as a method of enhancing the structural information obtained. We have applied a combination of two neutron diffraction experiments using isotopic substitution and one X-ray diffraction experiment to obtain the partial structure factors and pair distribution functions of liquid TlSe. We have applied the anomalous X-ray diffraction technique to glassy PSe using the Se K-edge. The results show that the first sharp diffraction peak observed in this glass arises almost entirely from the P-P correlations. We have applied the combined X-ray anomalous scattering and neutron diffraction technique to obtain the partial structure factors of glassy GeO(2). The results from two independent data sets have been compared and are in good agreement. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Barnes, AC (reprint author), Univ Bristol, HH Wills Phys Lab, Tyndall Ave,Royal Fort, Bristol BS8 1TL, Avon, England. EM a.c.barnes@bristol.ac.uk RI Saboungi, Marie-Louise/C-5920-2013 OI Saboungi, Marie-Louise/0000-0002-0607-4815 NR 28 TC 24 Z9 25 U1 0 U2 4 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 AUG PY 1999 VL 250 BP 393 EP 404 DI 10.1016/S0022-3093(99)00308-7 PN 2 PG 12 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 231EF UT WOS:000082294600001 ER PT J AU Sickafus, KE Matzke, H Hartmann, T Yasuda, K Valdez, JA Chodak, P Nastasi, M Verrall, RA AF Sickafus, KE Matzke, H Hartmann, T Yasuda, K Valdez, JA Chodak, P Nastasi, M Verrall, RA TI Radiation damage effects in zirconia SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 4th Workshop on Inert Matrix Fuel CY OCT 19-20, 1998 CL VILLIGEN, SWITZERLAND ID YTTRIA-STABILIZED ZIRCONIA; ION-IMPLANTATION; FUEL MATERIAL; IRRADIATION; SPINEL; POLYGONIZATION; BEAM; UO2 AB The evolution of radiation-induced damage in fully-stabilized, cubic zirconia (FSZ) (Y, Ca and Er dopants acting as stabilizers) and in pure, unstabilized, monoclinic zirconia, was investigated using Rutherford backscattering spectrometry and ion channeling (RBS/C), along with X-ray diffraction and transmission electron microscopy (TEM). FSZ crystals were irradiated with 340-400 keV Xe++ ions and at temperatures ranging from 170 to 300 K, or with I-127(+) ions (72 MeV) at temperatures ranging from 300 to 1170 K. No amorphization of zirconia was found under any irradiation condition, though in the case of 72 MeV I+ ion irradiations, the irradiation-induced defect microstructure was observed to produce dechanneling effects in RBS/C measurements that reach the 'random' level. Damage accumulation in Xe-ion irradiation experiments on FSZ crystals was found to progress in three stages: (1) formation of isolated defect clusters; (2) a transition stage in which damage increases rapidly over a small range of ion dose, due to the linking of dislocations and defect clusters: and (3) a 'saturation' stage in which damage accumulation is retarded or increases only slowly with ion dose. The FSZ crystal composition does not seem to alter significantly the dose-dependence of these damage stages. Unstabilized, monoclinic ZrO2 was observed to transform to a higher symmetry, tetragonal or cubic phase, upon 340 keV Xe++ ion irradiation to Xe fluences in excess of 5 x 10(18) m(-2) (dose equivalent, similar to 2 displacements per atom or dpa) at 120 K. This transformation was accompanied by a densification of the ZrO2 phase by similar to 5%. No amorphization of the pure ZrO2 was observed to a Xe++ ion fluence equivalent to a peak displacement damage level of about 680 dpa. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Commiss European Communities, Joint Res Ctr, Inst Transuranium Elements, D-7500 Karlsruhe, Germany. Kyushu Univ, Dept Nucl Engn, Fukuoka 812, Japan. Los Alamos Natl Lab, Technol & Safety Assessment Div, Los Alamos, NM USA. AECL Res, Chalk River Labs, CANDU Technol Dev, Fuel & Fuel Cycle Div, Chalk River, ON K0J 1J0, Canada. RP Sickafus, KE (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. EM kurt@lanl.gov NR 56 TC 240 Z9 243 U1 3 U2 62 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD AUG PY 1999 VL 274 IS 1-2 BP 66 EP 77 DI 10.1016/S0022-3115(99)00041-0 PG 12 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 233XX UT WOS:000082453400012 ER PT J AU Hassanein, A Konkashbaev, I AF Hassanein, A Konkashbaev, I TI Comprehensive physical models and simulation package for plasma/material interactions during plasma instabilities SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT 13th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices CY MAY 18-22, 1998 CL SAN DIEGO, CALIFORNIA SP Gen Atomics Co, US DOE ID DISRUPTION; EROSION AB Damage to plasma-facing components (PFCs) from plasma instabilities remains a major obstacle to a successful tokamak concept. The extent of the damage depends on the detailed physics of the disrupting plasma, as well as on the physics of plasma-material interactions. A comprehensive computer package called High Energy Interaction with General Heterogeneous Target Systems (HEIGHTS) has been developed and consists of several integrated computer models that follow the beginning of a plasma disruption at the scrape-off layer (SOL) through the transport of the eroded debris and splashed target materials to nearby locations as a result of the deposited energy. The package can study, for the first time, plasma-turbulent behavior in the SOL and predict the plasma parameters and conditions at the divertor plate. Full two-dimensional (2-D) comprehensive radiation magnetohydrodynamic (MHD) models are coupled with target thermodynamics and liquid hydrodynamics to evaluate the integrated response of plasma-facing materials. Factors that influence the lifetime of plasma-facing and nearby components, such as loss of vapor cloud confinement and vapor removal due to MHD effects, damage to nearby components due to intense vapor radiation, melt splashing, and brittle destruction of target materials, are also modeled and discussed. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Troitsk Inst Innovat & Fus Res, Troitsk, Russia. RP Hassanein, A (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 19 TC 43 Z9 43 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD AUG 1 PY 1999 VL 273 IS 3 BP 326 EP 333 DI 10.1016/S0022-3115(99)00052-5 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 219LT UT WOS:000081609300013 ER PT J AU Xu, HF Wang, YF Barton, LL AF Xu, HF Wang, YF Barton, LL TI Application of a linear free energy relationship to crystalline solids of MO2 and M(OH)(4) SO JOURNAL OF NUCLEAR MATERIALS LA English DT Letter ID ZIRCONIA AB In this letter, a linear free energy relationship developed by Sverjensky and Moiling is used to predict the Gibbs free energies of formation of crystalline phases of M4+O2 and M4+(OH)(4) from the known thermodynamic properties of aqueous tetravalent cations (M4+). The modified Sverjensky and Moiling equation for tetravalent cations is expressed as Delta(Gg,Mv,X)(0) = a(MvX)Delta G(n,M4+)(0) + b(MvX) + beta(MvX)gamma(M4+), where the coefficients a(Mv)X, b(MvX) and beta(MvX) characterize a particular structural family of MvX, r(M4+) is the ionic radius of M4+ cation, Delta G(f,MvX)(0) is the standard Gibbs free energy of formation of MvX, and Delta G(n,M4+)(0) is the standard non-solvation energy of cation M4+. By fitting the equation to the existing thermodynamic data, the coefficients in the equation for the MO2 family minerals are estimated to be: a(Mv)X = 0.670, beta(MvX) = 32 (kcal/mol Angstrom), and b = -430.02 (kcal/mol). The constrained relationship can be used to predict the standard Gibbs free energies of formation of crystalline phases and fictive phases (i.e., phases which are thermodynamically unstable and do not occur at standard conditions) within the isostructural families of M4+O2 and M4+(OH)(4) if the standard Gibbs free energies of formation of the tetravalent cations are known. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. Sandia Natl Labs, Carlsbad, NM 88220 USA. Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA. RP Xu, HF (reprint author), Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. NR 16 TC 14 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD AUG 1 PY 1999 VL 273 IS 3 BP 343 EP 346 DI 10.1016/S0022-3115(99)00092-6 PG 4 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 219LT UT WOS:000081609300016 ER PT J AU Wang, GJ Volkow, ND Fowler, JS Logan, J Pappas, NR Wong, CT Hitzemann, RJ Netusil, N AF Wang, GJ Volkow, ND Fowler, JS Logan, J Pappas, NR Wong, CT Hitzemann, RJ Netusil, N TI Reproducibility of repeated measures of endogenous dopamine competition with [C-11]raclopride in the human brain in response to methylphenidate SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE [C-11]raclopride; methylphenidate; pharmacologic challenge; PET; reproducibility ID POSITRON EMISSION TOMOGRAPHY; EARLY PARKINSONS-DISEASE; NAIVE SCHIZOPHRENIC-PATIENTS; D2 RECEPTOR STATUS; C-11 RACLOPRIDE; D-2 RECEPTORS; DEPENDENT SUBJECTS; STRIATAL D-2; PET; AGE AB The measure of changes in synaptic dopamine (DA) concentration in response to the psychostimulant drug methylphenidate (MP) has been used as an indicator of responsiveness of the DA system. The purpose of this study was to assess the reproducibility of these measures. Methods: Seven healthy subjects were scanned with PET and [C-11]raclopride twice in the same day: 7 min after placebo or methylphenidate (0.5 mg/kg) administration. In parallel we also measured the physiologic and behavioral responses to placebo and to methylphenidate. The same procedures were repeated 1-2 wk later to assess test-retest reproducibility. Results: Measures of plasma to brain transfer constant (K1), striatal distribution volume (DVstr) and DA D-2 receptor availability (Bmax/Kd), for the placebo condition were similar for the first (El) and second (E2) evaluations (Bmax/Kd, E1: 2.77 +/- 0.44; E2: 2.97 +/- 0.44). MP administration did not change K1, but it significantly decreased DVstr (E1: -25.9% +/- 8.7%, P less than or equal to 0.0002; E2: -20.7% +/- 11.7%, P less than or equal to 0.007) and Bmax/Kd (E1: -18.4% +/- 8.7%, P less than or equal to 0.002; E2: -13.4% +/- 9.2%, P less than or equal to 0.008), and the magnitude of these changes, though lower for E2, did not differ significantly MP increased pulse rate (E1: +64% +/- 43%, P less than or equal to 0.002; E2: +69% +/- 33%, P less than or equal to 0.001), systolic pressure (E1: +37% +/- 19%, P less than or equal to 0.0006; E2: +29% =/- 15%, P less than or equal to 0.0009), self reports for drug effects (0: nothing to 10: extreme) of "rush" (E1: +8 +/- 3, P less than or equal to 0.0004; E2: +6 +/- 4, P less than or equal to 0.01) and "high" (E1: +8 +/- 3, P less than or equal to 0.0001, E2: +8 +/- 3, P less than or equal to 0.0003), anxiety (El: +5 +/- 4, P less than or equal to 0.02; E2: +4 +/- 4, P = 0.1) and restlessness (E1: +4 +/- 4, P less than or equal to 0.04; E2: +4 +/- 5, P = 0.1). The magnitude of the cardiovascular and behavioral effects did not differ between El and E2. Conclusion: MP-induced changes in striatal DV and in Bmax/Kd, as well as the behavioral and cardiovascular effects, were reproducible with repeated administration. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. SUNY Stony Brook, Dept Radiol, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. Vet Affairs Med Ctr, Psychiat Serv, Northport, NY USA. RP Wang, GJ (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. FU NIAAA NIH HHS [AA 09481-04]; NIDA NIH HHS [DA 06891-02] NR 41 TC 37 Z9 38 U1 0 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD AUG PY 1999 VL 40 IS 8 BP 1285 EP 1291 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 224MF UT WOS:000081902300010 PM 10450679 ER PT J AU Autrey, T Foster, N Klepzig, K AF Autrey, T Foster, N Klepzig, K TI Nanojoules, nanoliters and nanosecond calorimetry SO JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY LA English DT Article DE photoacoustic; time-resolved; nanoscale; capillary ID RESOLVED PHOTOACOUSTIC CALORIMETRY; HIGH-PRESSURE; ELECTRON-TRANSFER; BOND STRENGTHS; N-HEPTANE; SPECTROSCOPY; ENERGY; PHOTOLYSIS; ENERGETICS; MOLECULES AB A nano-scale time-resolved calorimetric experimental approach is described using a photoacoustic cell made from narrow-bore flexible fused-silica capillary tubing. The fused silica capillary permits the transmission of an excitation source from the deep UV to the near infrared. Methods to couple the excitation energy into the sample and the acoustic energy away from the sample to the detector are discussed. To demonstrate the unique capabilities of the fused silica capillary cell, the excited triplet state energy (E-t) and lifetime (tau) of benzophenone (Bp) in the presence and absence of a quencher was measured. Irradiation of an air-saturated acetonitrile solution of Bp in the nano-scale photoacoustic cell, (i.e., absorption of ca. 100 nJ in a sample volume of 30 nl), yielded E-t = 69.5 +/- 1.4 kcal/mol and a tau of a few hundred nanoseconds. In the presence of potassium iodide (KI), a Bp*(3) quencher, the lifetime was significantly reduced. The rate of tripler quenching by KI (k(q) = 3.9 +/- 0.2 x 10(9) M-1 s(-1)) was determined from the slope of the Stern-Volmer plot of 1/tau observed versus quencher concentration. (C) 1999 Elsevier Science S.A. All rights reserved. C1 Pacific NW Natl Lab, Dept Chem Sci, Environm & Hlth Sci Div, Richland, WA 99352 USA. RP Autrey, T (reprint author), Pacific NW Natl Lab, Dept Chem Sci, Environm & Hlth Sci Div, POB 999, Richland, WA 99352 USA. NR 28 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 1010-6030 J9 J PHOTOCH PHOTOBIO A JI J. Photochem. Photobiol. A-Chem. PD AUG PY 1999 VL 125 IS 1-3 BP 13 EP 19 DI 10.1016/S1010-6030(99)00054-4 PG 7 WC Chemistry, Physical SC Chemistry GA 227VA UT WOS:000082099600002 ER PT J AU Dukowicz, JK Greatbatch, RJ AF Dukowicz, JK Greatbatch, RJ TI Evolution of mean-flow Fofonoff gyres in barotropic quasigeostrophic turbulence SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID EQUILIBRIUM STATISTICAL-MECHANICS; SCALE OCEAN MODEL; POTENTIAL VORTICITY; GEOSTROPHIC TURBULENCE; TOPOGRAPHIC STRESS; NORTH-ATLANTIC; CIRCULATION; DRIVEN; PARAMETERIZATION AB Numerical experiments are performed over a wide range of parameters to show that mean flows in the form of Fofonoff gyres, characterized by a linear relationship between streamfunction and potential vorticity, are universally produced in the statistically steady state of inviscid unforced barotropic quasigeostrophic turbulence, provided that the initial state is sufficiently well resolved. Further, as the resolution is increased, the mean-how energy approaches the total energy, and the mean-flow potential enstrophy reaches a minimum value, which is lower than the value with no how. This is in agreement with the predictions of the theory of equilibrium statistical mechanics. The timescale for the appearance of these flows is on the order of 5-10 tau(e), where tau(e) is a mean eddy turnover time. When viscosity is turned on. the mean-flow Fofonoff gyres become internally homogenized and eventually disappear entirely as the flow decays to zero. This evolution of the gyres can be universally scaled with a timescale tau(nu) = delta(2)/nu, where delta is the Rhines scale and nu is the viscosity coefficient. There is an initial period of very rapid adjustment on a timescale of similar to 0.005 tau(nu) at the enstrophy accumulated at very high wave-numbers is dissipated, followed by an intermediate period with a timescale of similar to 0.04 tau(nu) during which the gyres are homogenized, and finally a period of gyre decay on a timescale of similar to 0.3 tau(nu). In general, there is a competition between the statistical tendency to organize the mean flow into Fofonoff gyres and the tendency for homogenization, with the tendency to form Fofonoff gyres being always overwhelmed given a sufficiently long time. Thus, the issue of whether statistical mean flows, such as Fofonoff gyres, emerge and play a role depends on the relative magnitude of the two timescales, tau(e) and tau(nu). C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Dalhousie Univ, Dept Oceanog, Halifax, NS, Canada. RP Dukowicz, JK (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, T-3 Mail Stop B216, Los Alamos, NM 87545 USA. NR 25 TC 11 Z9 11 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD AUG PY 1999 VL 29 IS 8 BP 1832 EP 1852 DI 10.1175/1520-0485(1999)029<1832:EOMFFG>2.0.CO;2 PN 1 PG 21 WC Oceanography SC Oceanography GA 236PG UT WOS:000082607300013 ER PT J AU Smith, RD AF Smith, RD TI The primitive equations in the stochastic theory of adiabatic stratified turbulence SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID OCEAN CIRCULATION MODELS; POTENTIAL VORTICITY; EDDY TRANSFER; GENERAL-CIRCULATION; TRACER TRANSPORTS; MOMENTUM; FLUXES; PARAMETERIZATION; SENSITIVITY; SURFACES AB The stochastic theory of compressible turbulent fluid transport recently developed by Dukowicz and Smith is applied to the ensemble-mean primitive equations (PEs) for adiabatic stratified flow. The theory predicts a generalized Gent-McWilliams form for the bolus velocity and a single symmetric positive-definite diffusivity tensor for along-isopycnal Fickian diffusion of layer thickness and tracer distributions. When the theory is applied to the active tracer potential vorticity it provides constraints on the form of the Reynolds correlation in the momentum equation, and the turbulence closure problem is reduced to the determination of one 2 x 2 symmetric diffusivity tensor and one scalar field related to the eddy kinetic energy. The role of the rotational eddy fluxes of thickness, tracers, and potential vorticity is investigated, and a key feature of the closure is that the mean PEs ilo not depend on the gauge field associated with the rotational component of thickness flux, thereby eliminating the need to parameterize it. The relationship between this closure and closure schemes proposed by others in the quasigeostrophic regime is discussed. II is shown that the eddy-induced transport velocity can be parameterized as diffusion of either thickness or potential vorticity, and the resulting closure schemes are equivalent in the quasigeostrophic regime. The implications of the theory for energy and enstrophy balances are also discussed. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Smith, RD (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, T-3,Mail Stop B216, Los Alamos, NM 87545 USA. NR 38 TC 18 Z9 18 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD AUG PY 1999 VL 29 IS 8 BP 1865 EP 1880 DI 10.1175/1520-0485(1999)029<1865:TPEITS>2.0.CO;2 PN 1 PG 16 WC Oceanography SC Oceanography GA 236PG UT WOS:000082607300015 ER PT J AU Tranquada, JM Ichikawa, N Kakurai, K Uchida, S AF Tranquada, JM Ichikawa, N Kakurai, K Uchida, S TI Charge segregation and antiferromagnetism in high-T-c superconductors SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE superconductors; neutron scattering; charge-density waves; spin-density waves ID COPPER-OXIDE SUPERCONDUCTORS; MUON SPIN RELAXATION; STRIPE-PHASE ORDER; MAGNETIC FLUCTUATIONS; LA2-XSRXCUO4; DEPENDENCE; PSEUDOGAP; LA1.6-XND0.4SRXCUO4; BI2SR2CACU2O8+DELTA; YBA2CU3O6.6 AB Local antiferromagnetism coexists with superconductivity in the cuprates. Charge segregation provides a way to reconcile these properties. Direct evidence for modulated spin and charge densities has been found in neutron and X-ray scattering studies of Nd-doped La2-xSrxCuO4. Here we discuss the nature of the modulation, and present some new results for a Zn-doped sample. Some of the open questions concerning the connections between segregation and superconductivity are described. (C) 1999 Elsevier Science Ltd, All rights reserved. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 113, Japan. Univ Tokyo, Inst Solid State Phys, Minato Ku, Tokyo 1068666, Japan. RP Tranquada, JM (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Tranquada, John/A-9832-2009 OI Tranquada, John/0000-0003-4984-8857 NR 33 TC 17 Z9 17 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1019 EP 1023 DI 10.1016/S0022-3697(99)00041-4 PG 5 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000005 ER PT J AU Yamada, K Kurahashi, K Endoh, Y Birgeneau, RJ Shirane, G AF Yamada, K Kurahashi, K Endoh, Y Birgeneau, RJ Shirane, G TI Neutron scattering study on electron-hole doping symmetry of high-T-c superconductivity SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE magnetic materials; superconductors; neutron scattering; superconductivity; spin-density waves ID SPIN CORRELATIONS; ORDER; LA2-XSRXCUO4 AB We review recent results of neutron scattering experiment on spin correlations for both hole-doped La2-xSr2CuO4+y and electron-doped Nd1.85Ce0.15CuO4+y superconductors, For the former, hole-doping induces an incommensurate spin density modulation along the Cu-O bonds. For the latter, we observed well-defined spin fluctuations in the superconducting phase (T-c approximate to 18 K) for the first time. In contrast to the hole-doping, the electron-doping induces no well-defined incommensurate spin modulation; the magnetic signal appears at ( pi, pi) with a q-width broader than in the as-grown antiferromagnetic phase. For both systems a static magnetic order was observed in the superconducting state. (C) 1999 Published by Elsevier Science Ltd. All rights reserved. C1 Kyoto Univ, Inst Chem Res, Uji 6110011, Japan. Tohoku Univ, Dept Phys, Sendai, Miyagi 98077, Japan. MIT, Dept Phys, Cambridge, MA 02139 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Yamada, K (reprint author), Kyoto Univ, Inst Chem Res, Uji 6110011, Japan. RI Yamada, Kazuyoshi/C-2728-2009 NR 16 TC 33 Z9 34 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1025 EP 1030 DI 10.1016/S0022-3697(99)00042-6 PG 6 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000006 ER PT J AU Shirane, G AF Shirane, G TI Magnetism of doped CuGeO3 SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE magnetic materials; oxides; neutron scattering; phase transitions ID SPIN-PEIERLS SYSTEMS; LONG-RANGE ORDER; ANTIFERROMAGNETIC PHASES; CU1-XZNXGEO3; EXCITATIONS; TRANSITION AB A review of the recent neutron scattering experiments on doped Cu(Zn,Mg)Ge(Si)O-3 is presented. A unique antiferromagnetic (AF) ordering co-exists with the spin-Peierls ordering (SP) and their spin wave profiles were characterized by inelastic neutron scattering. Very recently a novel phase diagram was proposed by Masuda et al. for Cu1-xMgxGeO3. At the critical concentration of 2.3% Mg, the SP phase suddenly disappears and only the AF phase remains at a higher x. The neutron scattering work by Nakao et al. further characterizes this interesting phase diagram. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Shirane, G (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 12 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1031 EP 1037 DI 10.1016/S0022-3697(99)00043-8 PG 7 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000007 ER PT J AU Kawano, H Takeya, H Yoshizawa, H Kadowaki, K AF Kawano, H Takeya, H Yoshizawa, H Kadowaki, K TI Weak ferromagnetic ordering in the superconducting state of (ErNi2B2C)-B-11 SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE superconductors; magnetic materials; neutron scattering; electrical conductivity; magnetic properties ID SINGLE-CRYSTAL GROWTH; FLUX-LINE-LATTICE; ANTIFERROMAGNETIC ORDER; MAGNETIC-STRUCTURE; VORTEX PHASE; ERNI2B2C; COEXISTENCE; TRANSITION; YNI2B2C; COMPETITION AB Recently a possible coexistence of weak ferromagnetism and superconductivity was proposed for ErNi2B2C. We have performed unpolarized neutron diffraction experiments on a large single crystal, and demonstrate that such an exotic phase is realized in this system below T-WF = 2.5 K, However, the virgin magnetization curve shows diamagnetic behavior even below T-WF, indicating that there is no spontaneous vortex phase in a ZFC process. In addition, we also discuss future prospects of our project based on the results presented in this paper. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Natl Res Inst Met, Tsukuba, Ibaraki 3050047, Japan. Univ Tokyo, Neutron Scattering Lab, ISSP, Tokai, Ibaraki 3191106, Japan. Univ Tsukuba, Inst Mat Sci, Tsukuba, Ibaraki 3050006, Japan. RP Kawano, H (reprint author), RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. RI Kawano-Furukawa, Hazuki/M-7695-2016; Kawano-Furukawa, Hazuki/M-7646-2016 OI Kawano-Furukawa, Hazuki/0000-0003-4713-3727; Kawano-Furukawa, Hazuki/0000-0003-4713-3727 NR 30 TC 35 Z9 35 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1053 EP 1057 DI 10.1016/S0022-3697(99)00046-3 PG 5 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000010 ER PT J AU Yethiraj, M Kawano, H Paul, DM Tomy, CV Takeya, H Yoshizawa, H AF Yethiraj, M Kawano, H Paul, DM Tomy, CV Takeya, H Yoshizawa, H TI Nonlocal effects in the superconductor (YNi2B2C)-B-11 SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE superconductivity; non-local effects; rare-earth nickel borocarbide ID YNI2B2C AB Flux lines repel each other, thus a hexagonal lattice which maximizes the distance between them is generally the lowest energy configuration. In the rare-earth nickel borocarbide superconductor YNi2B2C, square lattices of flux lines have been observed when the field is parallel to the c-axis, Using the c-axis penetration depth as a gauge, we find that the cross-section of an individual flux line has a four-fold symmetry, which makes square lattices energetically favored over the more prosaic hexagonal ordering. The dependence of the penetration depth within the basal plane is discussed. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Natl Res Inst Met, Tsukuba, Ibaraki 305, Japan. Univ Tokyo, ISSP, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. RP Yethiraj, M (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Kawano-Furukawa, Hazuki/M-7695-2016; Kawano-Furukawa, Hazuki/M-7646-2016 OI Kawano-Furukawa, Hazuki/0000-0003-4713-3727; Kawano-Furukawa, Hazuki/0000-0003-4713-3727 NR 8 TC 0 Z9 0 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1059 EP 1062 DI 10.1016/S0022-3697(99)00047-5 PG 4 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000011 ER PT J AU Kimura, H Matsushita, H Hirota, K Endoh, Y Yamada, K Lee, YS Kastner, MA Birgeneau, RJ AF Kimura, H Matsushita, H Hirota, K Endoh, Y Yamada, K Lee, YS Kastner, MA Birgeneau, RJ TI Neutron scattering study of incommensurate elastic magnetic peaks in La1.88Sr0.12CuO4 SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE superconductors; neutron scattering; magnetic properties; superconductivity ID SPIN CORRELATIONS; LA2-XSRXCUO4; ORDER; LA2CUO4; LA2-XBAXCUO4; EXCITATIONS; PURE AB Elastic magnetic peaks around (pi, pi) have been studied in La2-xSrxCuO4 (LSCO) by neutron scattering. Recently in super-conducting LSCO of x = 0.12, we found that the incommensurate elastic peak (IC peak) appears around 31 K which is very close to T-c. The line width reaches almost resolution limit, which indicates that the static magnetic correlation length exceeds 200 Angstrom(-1) isotropically in the CuO2 planes. Furthermore recently in the course of studying the IC peak, we found the new experimental condition where the signals can be observed more clearly. The signal-to-noise ratio (S/N) is much more improved (similar to 1.4) than that at the previous experiment (similar to 0.6). (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan. Kyoto Univ, Inst Chem Res, Uji, Kyoto 6100011, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. RP Kimura, H (reprint author), Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan. RI Yamada, Kazuyoshi/C-2728-2009 NR 12 TC 5 Z9 5 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1067 EP 1070 DI 10.1016/S0022-3697(99)00049-9 PG 4 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000013 ER PT J AU Wakimoto, S Yamada, K Ueki, S Shirane, G Lee, YS Kastner, MA Hirota, K Gehring, PM Endoh, Y Birgeneau, RJ AF Wakimoto, S Yamada, K Ueki, S Shirane, G Lee, YS Kastner, MA Hirota, K Gehring, PM Endoh, Y Birgeneau, RJ TI Neutron scattering study of elastic magnetic signals in superconducting La1.94Sr0.06CuO4 SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE superconductors; crystal growth; neutron scattering; magnetic properties; superconductivity ID LA2-XSRXCUO4 AB Recent neutron-scattering experiments on La2-xSrxCuO4 single crystals by Wakimoto et al. (unpublished) have revealed that elastic magnetic peaks appear at low temperatures in both insulating (x = 0.02-0.05) and superconducting (x = 0.06) samples. We have carried out further investigations particularly on the elastic incommensurate peaks for x = 0.06, and found that the integrated intensity drastically changes across the low temperature insulator-superconductor boundary; the intensity of x = 0.06 is four times smaller than that of x = 0.05, whereas the intensity in the insulating region stays constant. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, College Pk, MD 20742 USA. RP Hirota, K (reprint author), Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan. RI Yamada, Kazuyoshi/C-2728-2009; OI Gehring, Peter/0000-0002-9236-2046 NR 7 TC 5 Z9 5 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1079 EP 1081 DI 10.1016/S0022-3697(99)00052-9 PG 3 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000016 ER PT J AU Nishi, M Kakurai, K Fujii, Y Katano, S Akimitsu, J Yethiraj, M Fernandez-baca, JA AF Nishi, M Kakurai, K Fujii, Y Katano, S Akimitsu, J Yethiraj, M Fernandez-baca, JA TI New aspects of the b*-LA phonon of CuGeO3 SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE oxides; neutron scattering; phonons; lattice dynamics; phase transitions ID SPIN-PEIERLS TRANSITION; LATTICE-DYNAMICS; COMPOUND CUGEO3; SCATTERING AB We performed high resolution measurements of the b*-LA phonon branch of CuGeO3 by inelastic neutron scattering. From the results it was clarified that the b*-LA broad branch reported earlier is composed of two phonon branches with excitation energies very nearby. The second branch close to this b*-LA mode cannot be assigned in the space group Pbmm and it may indicate that a twisting motion of GeO4 tetrahedra couples to the b*-LA mode, This coupling may be an indispensable ingredient for the spin-Peierls transition in CuGeO3. (C) 1999 Elsevier Science Ltd, All rights reserved. C1 Univ Tokyo, ISSP, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. JAERI, ASRC, Tokai, Ibaraki 3191196, Japan. Aoyama Gakuin Univ, Dept Phys, Setagaya Ku, Tokyo 1578572, Japan. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Nishi, M (reprint author), Univ Tokyo, ISSP, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. RI Fernandez-Baca, Jaime/C-3984-2014 OI Fernandez-Baca, Jaime/0000-0001-9080-5096 NR 12 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1109 EP 1111 DI 10.1016/S0022-3697(99)00062-1 PG 3 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000024 ER PT J AU Nakao, H Nishi, M Fujii, Y Masuda, T Tsukada, I Uchinokura, K Hirota, K Shirane, G AF Nakao, H Nishi, M Fujii, Y Masuda, T Tsukada, I Uchinokura, K Hirota, K Shirane, G TI Neutron scattering study of doped spin-Peierls compound (Cu1-xMgx)GeO3 SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE magnetic material; neutron scattering; phase transitions; magnetic properties ID ANTIFERROMAGNETIC PHASES; TRANSITION; CUGEO3 AB Comprehensive neutron scattering experiments were carried out on a series of wide concentration range x = 0.017-0.082 in (Cu1-xMgx)GeO3. The obtained temperature-concentration T-x phase diagram is consistent with the previous magnetic susceptibility data except for the spin-Peierls (SP) phase in a region at x > x(c), where the existence of short-range ordered SP state was observed for the first time even below T-SP (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Tokyo, Inst Solid State Phys, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 1138656, Japan. Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Nakao, H (reprint author), Univ Tokyo, Inst Solid State Phys, Neutron Scattering Lab, 106-1 Shirakata, Tokai, Ibaraki 3191106, Japan. NR 4 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1117 EP 1119 DI 10.1016/S0022-3697(99)00069-4 PG 3 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000026 ER PT J AU Matsuda, M Katsumata, K Zheludev, A Shapiro, SM Shirane, G AF Matsuda, M Katsumata, K Zheludev, A Shapiro, SM Shirane, G TI Neutron scattering study in BaNiO2 SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE oxides; crystal growth; neutron scattering; magnetic properties ID STATE AB Inelastic neutron scattering measurements have been performed on a single crystal of BaNiO2. A paramagnetic scattering originating from dilute moments was observed, suggesting that BaNiO2, is non-magnetic. The possible origin of the nonmagnetic ground state is discussed. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Matsuda, M (reprint author), RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. RI Matsuda, Masaaki/A-6902-2016 OI Matsuda, Masaaki/0000-0003-2209-9526 NR 13 TC 2 Z9 2 U1 0 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1121 EP 1123 DI 10.1016/S0022-3697(99)00070-0 PG 3 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000027 ER PT J AU Kajimoto, R Yoshizawa, H Kawano, H Kuwahara, H Tokura, Y AF Kajimoto, R Yoshizawa, H Kawano, H Kuwahara, H Tokura, Y TI Quasi-elastic ferromagnetic excitations in Nd1/2Sr1/2MnO3 SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE oxides; crystal growth; neutron scattering; magnetic properties ID SPIN DYNAMICS; TRANSITION; FIELD AB We have investigated the ferromagnetic spin fluctuations in Nd1/2Sr1/2MnO3, which shows relatively weak colossal magnetoresistance (CMR) behavior at Tc. An intense quasielastic fluctuation, a so-called central peak, develops at around the ferromagnetic transition temperature. By comparing the results with those observed in other CMR manganites, we examine which feature of the central component is essential to the CMR phenomenon. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Tokyo, ISSP, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. JRCAT, Tsukuba, Ibaraki 3058562, Japan. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 1138656, Japan. RP Kajimoto, R (reprint author), Univ Tokyo, ISSP, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. RI Tokura, Yoshinori/C-7352-2009; Kawano-Furukawa, Hazuki/M-7695-2016; Kawano-Furukawa, Hazuki/M-7646-2016 OI Kawano-Furukawa, Hazuki/0000-0003-4713-3727; Kawano-Furukawa, Hazuki/0000-0003-4713-3727 NR 15 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1177 EP 1180 DI 10.1016/S0022-3697(99)00077-3 PG 4 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000041 ER PT J AU Kosugi, T Amezawa, K Yamamoto, N Kawano, S Fernandez-Baca, JA AF Kosugi, T Amezawa, K Yamamoto, N Kawano, S Fernandez-Baca, JA TI Neutron diffraction studies of the magnetic structures of Tb0.76Y0.24 Single crystal under high pressure SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE magnetic materials; high pressure; neutron scattering; magnetic structure ID SCATTERING; HOLMIUM; ERBIUM AB The effects of high pressure on the magnetic structure of Tb0.76Y0.24 have been investigated by neutron diffraction using a clamp type high pressure cell, Pressure was applied up to about 2.4 GPa and temperature, down to about 10 K, The magnetic structure of Tb0.76Y0.24 exhibits a helical phase both under high pressure and at ambient pressure, The helical pitch shows a lock-in feature below about 100 K, With increasing pressure, the helical pitch is enhanced, and a lock-in feature at low temperature still remains, (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Kyoto Univ, Grad Sch Human & Environm Studies, Kyoto 6068501, Japan. Kyoto Univ, Inst Res Reactor, Osaka 5900494, Japan. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Kyoto Univ, Grad Sch Human & Environm Studies, Kyoto 6068501, Japan. RI Fernandez-Baca, Jaime/C-3984-2014 OI Fernandez-Baca, Jaime/0000-0001-9080-5096 NR 10 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 EI 1879-2553 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1225 EP 1228 DI 10.1016/S0022-3697(99)00090-6 PG 4 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000054 ER PT J AU Loong, CK AF Loong, CK TI Neutron scattering studies of industry-relevant materials: connecting microscopic behavior to applied properties SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE ceramics; nanostructures; neutron scattering; microstructure; phonons ID DENSITY-OF-STATES; LEAD-INDIUM PHOSPHATE; EARTH ENERGY-LEVELS; MAGNETIC-PROPERTIES; TEMPERATURE-DEPENDENCE; LATTICE-PARAMETERS; MODIFIED ZIRCONIA; PHONON DENSITIES; NITRIDE; ALUMINA AB Certain systems of oxides, nitrides and carbides have been recognized as the basic components of advanced materials for applications such as engineering and electronic ceramics, catalysts, sensors, etc. under extreme environments. An understanding of the basic atomic and electronic properties of these systems will benefit enormously the industrial development of new materials featuring tailored properties. We present an overview of neutron scattering studies of the crystal phases, microstructure, phonon and magnetic excitations of key materials including rare-earth phosphates, phosphate glasses, nanostructured metal oxides, as well as silicon nitride and silicon carbide ceramics. A close collaboration among neutron scattering experimentation, molecular-dynamics simulation and material synthesis is emphasized. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Loong, CK (reprint author), Argonne Natl Lab, Div Intense Pulsed Neutron Source, Bldg 360, Argonne, IL 60439 USA. NR 37 TC 1 Z9 1 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1397 EP 1401 DI 10.1016/S0022-3697(99)00127-4 PG 5 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000091 ER PT J AU Suzuya, K Price, DL Loong, CK Kohara, S AF Suzuya, K Price, DL Loong, CK Kohara, S TI The structure of magnesium phosphate glasses SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE glasses; neutron scattering ID X-RAY-DIFFRACTION AB The structures of (MgO)(x)(P2O5)(100-x) glasses, with x = 40, 50, 60, have been studied by neutron diffraction. For all glasses the Mg-O coordination number NMg-O is around 6, Although no abrupt change in NMg-O around the metaphosphate composition (x = 50) was observed, the mean value and distribution of Mg-O distances changed with increases in the MgO content from 50 to 60 mol% and 40 to 50 mol%, respectively. The quasi-periodicity of the intermediate-range order contracts with an increase in MgO content from 50 to 60 mol%, These changes may represent the structural origin of the phosphate glass anomaly, (C) 1999 Elsevier Science Ltd, All rights reserved. C1 Japan Atom Energy Res Inst, SPring 8, Sayo, Hyogo 6795143, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. Japan Synchtrotron Radiat Res Inst, Sayo, Hyogo 6795198, Japan. RP Suzuya, K (reprint author), Japan Atom Energy Res Inst, SPring 8, Sayo, Hyogo 6795143, Japan. EM suzuya@spring8.or.jp RI Price, David Long/A-8468-2013 NR 16 TC 19 Z9 20 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 EI 1879-2553 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1457 EP 1460 DI 10.1016/S0022-3697(99)00140-7 PG 4 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000105 ER PT J AU Lee, CH Yu, KL Huang, JCA Felcher, G AF Lee, CH Yu, KL Huang, JCA Felcher, G TI Study of the interface roughness using polarized neutron and X-ray reflectivity on MBE permalloy thin films SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 7th Institute-for-Solid-State-Physics Symposium on Frontiers in Neutron Scattering Research (ISSP7) CY NOV 24-27, 1998 CL TOKYO, JAPAN SP Inst Solid State Phys DE thin films; X-ray diffraction; neutron scattering; magnetic structure ID GIANT MAGNETORESISTANCE AB Polarized neutron and X-ray reflectivity methods have been used to study the permalloy epitaxial thin films on sapphire with Cr as a buffer layer. The reflectivity result indicates that the magnetic interface is smoother than the chemical interface. It is possible that the magnetic moment of the intrusive Ni or Fe atoms across the interface can be assimilated by the near-by Cr atoms or the other way around. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Natl Tsing Hua Univ, Dept Engn & Syst Sci, Hsinchu 30043, Taiwan. Natl Tsing Hua Univ, Nucl Reactor Div, Hsinchu 30043, Taiwan. Natl Cheng Kung Univ, Dept Phys, Tainan 701, Taiwan. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Lee, CH (reprint author), Natl Tsing Hua Univ, Dept Engn & Syst Sci, Hsinchu 30043, Taiwan. NR 9 TC 2 Z9 2 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD AUG-SEP PY 1999 VL 60 IS 8-9 BP 1491 EP 1494 DI 10.1016/S0022-3697(99)00151-1 PG 4 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 226AK UT WOS:000081998000112 ER PT J AU Bass, BR McAfee, WJ Bryson, JW Pennell, WE AF Bass, BR McAfee, WJ Bryson, JW Pennell, WE TI An investigation of cladding effects on shallow-flaw fracture toughness of reactor pressure vessel steel under prototypic biaxial loading SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB Potential structural-integrity benefits or liabilities of the stainless steel cladding on the inner surface of a reactor pressure vessel (RPV) are important considerations in the effort to refine or improve safety assessment procedures applied to RPVs, Clad-beam tests were carried out to investigate and quantify effects of the clad structure on fracture initiation toughness of through-clad shallow surface flaws in RPV material. A cruciform beam specimen Was developed at ORNL to introduce a prototypic, far-field, out-of-plane biaxial stress component that provides a linear approximation of the nonlinear stress distribution generated by thermo-mechanical loading transients in an RPV. The cruciform specimens (102-mm-thick test section) were fabricated from RPV shelf segments available from a canceled pressurized-water reactor plant, The specimens were tested under biaxial load ratios ranging from 0.0 (uniaxial) to 1.0 (full biaxial), the ratio being defined as the total load applied to the transverse beam arms divided by that applied to the longitudinal arms, The rest results imply that biaxial loading is effective in reducing the shallow-flaw-fracture toughness of the clad/heat-affected zone/structural-weld region of the RPV shell below that determined from uniaxial loading conditions. The lowest toughness value from the clad cruciform specimens tested under biaxial loading is only slightly above the ASME Section XI K-Ic curve. For all biaxiality ratios, the test results imply that shallow-flaw fracture toughness data from the RPV structural weld material are significantly lower than that obtained from a high-yield strength plate material. C1 Oak Ridge Natl Lab, Heavy Sect Steel Technol Program, Oak Ridge, TN 37831 USA. RP Bass, BR (reprint author), Oak Ridge Natl Lab, Heavy Sect Steel Technol Program, POB 2009, Oak Ridge, TN 37831 USA. NR 21 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 USA SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD AUG PY 1999 VL 121 IS 3 BP 257 EP 268 DI 10.1115/1.2883701 PG 12 WC Engineering, Mechanical SC Engineering GA 227VP UT WOS:000082100900004 ER PT J AU Siewert, CE Wright, SJ AF Siewert, CE Wright, SJ TI Efficient eigenvalue calculations in radiative transfer SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article AB An efficient method is used to compute the eigenvalues required in a discrete-ordinates solution to a special class of radiative-transfer problems. The basis for this computation is an algorithm for finding eigenvalues of a matrix that consists of the sum of a diagonal matrix and a rank-one matrix, a form that can arise in a discrete-ordinates solution of some basic transport problems. To illustrate the efficiency of the approach, a radiative-transfer problem relevant to a non-gray model with scattering that allows complete frequency redistribution is discussed. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 N Carolina State Univ, Dept Math, Raleigh, NC 27695 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Siewert, CE (reprint author), N Carolina State Univ, Dept Math, Box 8205, Raleigh, NC 27695 USA. NR 7 TC 15 Z9 15 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD AUG PY 1999 VL 62 IS 6 BP 685 EP 688 DI 10.1016/S0022-4073(98)00099-5 PG 4 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 196CT UT WOS:000080292000005 ER PT J AU Mong, GM Campbell, JA AF Mong, GM Campbell, JA TI Analysis of phosphate-related components in Hanford tank wastes SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article AB Several organophosphorus compounds including tributyl phosphate (TBP), bis-(2-ethylhexyl) phosphate (D2EHP), and dibutyl butyl phosphonate (DBBP) were used as extractants at the Hanford site. The mass spectral fragmentation patterns of various organosphosphorus compounds have been interpreted and used to predict the identity of phosphate-related components and their degradation products in tank waste. C1 Pacific NW Lab, Adv Organ Analyt Methods Grp, Richland, WA 99352 USA. RP Mong, GM (reprint author), Pacific NW Lab, Adv Organ Analyt Methods Grp, POB 999, Richland, WA 99352 USA. NR 14 TC 6 Z9 6 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD AUG PY 1999 VL 241 IS 2 BP 297 EP 306 DI 10.1007/BF02347465 PG 10 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 225XN UT WOS:000081991400007 ER PT J AU Banaszak, JE Rittmann, BE Reed, DT AF Banaszak, JE Rittmann, BE Reed, DT TI Subsurface interactions of actinide species and microorganisms: Implications for the bioremediation of actinide-organic mixtures SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Review ID NUCLEAR WASTE-DISPOSAL; SOLUBLE MICROBIAL PRODUCTS; METAL-NITRILOTRIACETATE COMPLEXES; CHELATOBACTER-HEINTZII; CITRATE COMPLEXES; NATURAL-WATERS; TOXIC METALS; REDUCTIVE DEHALOGENATION; PSEUDOMONAS-FLUORESCENS; METHANOGENIC CONDITIONS AB By reviewing how microorganisms interact with actinides in subsurface environments, we assess how bioremediation controls the fate of actinides. Actinides often ate co-contaminants with strong organic chelators, chlorinated solvents, and fuel hydrocarbons. Bioremediation can immobilize the actinides, biodegrade the co-contaminants, or both. Actinides at the IV oxidation state are the least soluble, and microorganisms accelerate precipitation by altering the actinide's oxidation state or its speciation. We describe how microorganisms directly oxidize or reduce actinides and how microbiological reactions that biodegrade strong organic chelators, alter the pH, and consume or produce precipitating anions strongly affect actinide speciation and, therefore, mobility. We explain why inhibition caused by chemical or radiolytic toxicities uniquely affects microbial reactions. Due to the complex interactions of the microbiological and chemical phenomena, mathematical modeling is an essential tool for research on and application of bioremedation involving co-contamination with actinides, We describe the development of mathematical models that link microbiological and geochemical reactions. Throughout, we identify the key research needs. C1 Northwestern Univ, Dept Civil Engn, Evanston, IL 60208 USA. Argonne Natl Lab, Div Chem Technol, Actinide Speciat & Chem Grp, Argonne, IL 60439 USA. RP Banaszak, JE (reprint author), Northwestern Univ, Dept Civil Engn, 2145 Sheridan Rd, Evanston, IL 60208 USA. NR 291 TC 47 Z9 49 U1 0 U2 15 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD AUG PY 1999 VL 241 IS 2 BP 385 EP 435 DI 10.1007/BF02347481 PG 51 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 225XN UT WOS:000081991400023 ER PT J AU Chamberlin, RM Abney, KD AF Chamberlin, RM Abney, KD TI Strontium and cesium extraction into hydrocarbons using alkyl cobalt dicarbollide and polyethylene glycols (vol 240, pg 547, 1999) SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Correction C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Chamberlin, RM (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, CST-11,MS J514, Los Alamos, NM 87545 USA. RI Chamberlin, Rebecca/A-1335-2011 OI Chamberlin, Rebecca/0000-0001-6468-7778 NR 1 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD AUG PY 1999 VL 241 IS 2 BP 437 EP 438 DI 10.1007/BF02347483 PG 2 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 225XN UT WOS:000081991400025 ER PT J AU Woodward, NB AF Woodward, NB TI Competitive macroscopic deformation processes SO JOURNAL OF STRUCTURAL GEOLOGY LA English DT Article ID FAULT-PROPAGATION FOLDS; BRITTLE-DUCTILE TRANSITION; SINGLE-LAYER FOLDS; LOST RIVER RANGE; THRUST BELT; SEDIMENTARY-ROCKS; SOUTHWEST VIRGINIA; TRANSECTED FOLDS; DETACHMENT FOLDS; RIDGE PROVINCE AB Macroscopic deformation mechanisms such as folding, fracturing-faulting and formation of rock fabrics compete with one another in a fashion similar to the competition among crystalline deformation mechanisms such as cataclasis, grain boundary sliding, dislocation creep and diffusive mass transfer. Many authors seek to develop a unique structural chronology for a given field area based on what are considered exclusive overprinting relationships between structures. In contrast the approach taken here suggests that relative changes in external or internal variables within a rock mass can cause significantly different 'dominant' types of macroscopic deformation to be developed in hand specimen and/or outcrop at the same time. Rather than representing distinct structural 'facies', observed dominant macroscopic features are waypoints in continuum processes. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 US DOE, Geosci Res Program, Germantown, MD 20874 USA. RP Woodward, NB (reprint author), US DOE, Geosci Res Program, SC-15,19901 Germantown Rd, Germantown, MD 20874 USA. NR 92 TC 6 Z9 6 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0191-8141 J9 J STRUCT GEOL JI J. Struct. Geol. PD AUG-SEP PY 1999 VL 21 IS 8-9 BP 1209 EP 1218 DI 10.1016/S0191-8141(99)00076-0 PG 10 WC Geosciences, Multidisciplinary SC Geology GA 229KK UT WOS:000082193600037 ER PT J AU Rose, JH Bilgen, M Roux, P Fink, M AF Rose, JH Bilgen, M Roux, P Fink, M TI Time-reversal mirrors and rough surfaces: Theory SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID ACOUSTICS AB A systematic study is presented of the sensitivity of acoustic time-reversal mirrors (TRMs) to errors. One result is a novel acoustic method for determining the root-mean-square, rms, height and the surface-height autocorrelation function of rough surfaces. In particular, the effects of misregistering a TRM are studied with respect to a rough surface-the reflected wavefield is recorded in one place, time reversed, and then rebroadcast in a second place. This displacement causes the signal to depend importantly on the surface's rms height and autocorrelation function. Simple closed-form formulas are presented for determining, the rms height and the normalized surface-height autocorrelation function for both deterministic and randomly rough surfaces. Also presented is a numerical study that illustrates the statistical uncertainty in and the spatial resolution of the proposed method. An accompanying experimental article tests the proposed method with measurements made on a number of different rough surfaces. (C) 1999 Acoustical Society of America. [S001-4966(99)02107-4]. C1 Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Univ Kansas, Med Ctr, Dept Radiol, Kansas City, KS 66160 USA. Univ Paris 07, ESPCI, Lab Ondes & Acoust, F-75005 Paris, France. RP Rose, JH (reprint author), Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RI roux, philippe/B-8538-2014; fink, mathias/M-9437-2016; OI Fink, Mathias/0000-0002-8494-7562 NR 12 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD AUG PY 1999 VL 106 IS 2 BP 716 EP 723 DI 10.1121/1.427089 PG 8 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 225YN UT WOS:000081993700020 ER EF