FN Thomson Reuters Web of Science™ VR 1.0 PT J AU NEWMAN, P STOLARSKI, R SCHOEBERL, M MCPETERS, R KRUEGER, A AF NEWMAN, P STOLARSKI, R SCHOEBERL, M MCPETERS, R KRUEGER, A TI THE 1990 ANTARCTIC OZONE HOLE AS OBSERVED BY TOMS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DEPLETION AB The 1990 Antarctic ozone hole matched the record 1987 ozone hole in depth, duration, and area. During the formation phase of the hole (August), total ozone values were the lowest yet recorded. The decline rate approximately matched the record 1987 decline, and reached a minimum of 125 Dobson Units on October 4, 1990. October total ozone averages were marginally higher than 1987. As during 1987, the 1990 total ozone values within the hole slowly and steadily increased during the mid-October through November period. The ozone hole breakup was the latest yet recorded (early December), with low ozone values persisting over the pole through December, setting a record low for December average polar ozone. Temperatures were near average during the early spring, but were below normal for the late-spring. Temperatures in the early spring of 1990 were substantially warmer than those observed in the early spring of 1987. RP NEWMAN, P (reprint author), NOAA,GODDARD SPACE FLIGHT CTR,CODE 916,ROCKVILLE,MD 20852, USA. RI Newman, Paul/D-6208-2012; Stolarski, Richard/B-8499-2013; McPeters, Richard/G-4955-2013 OI Newman, Paul/0000-0003-1139-2508; Stolarski, Richard/0000-0001-8722-4012; McPeters, Richard/0000-0002-8926-8462 NR 18 TC 19 Z9 19 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR PY 1991 VL 18 IS 4 BP 661 EP 664 DI 10.1029/91GL00546 PG 4 WC Geosciences, Multidisciplinary SC Geology GA FG828 UT WOS:A1991FG82800022 ER PT J AU KNIPP, DJ RICHMOND, AD EMERY, B CROOKER, NU DELABEAUJARDIERE, O EVANS, D KROEHL, H AF KNIPP, DJ RICHMOND, AD EMERY, B CROOKER, NU DELABEAUJARDIERE, O EVANS, D KROEHL, H TI IONOSPHERIC CONVECTION RESPONSE TO CHANGING IMF DIRECTION SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; MAPPING ELECTRODYNAMIC FEATURES; HIGH-LATITUDE IONOSPHERE; ELECTRIC-FIELD; LOCALIZED OBSERVATIONS; PATTERNS AB By combining ground-based and satellite-based measurements of ionospheric electric fields, conductivities and magnetic perturbations, we are able to examine the characteristics of instantaneous, ionospheric convection patterns associated with changing directions of the Interplanetary Magnetic Field (IMF). In response to a rapid southward-to-northward turning of the IMF on 23 July 1983, the ionospheric convection reconfigured over a period of 40 minutes. The configuration changed from a conventional two-cell pattern to a contracted four-cell pattern, with reversed convection cells in the high-latitude dayside, associated with a strong potential drop of about 75 kV. Later, in response to a gradual rotation of the IMF from the +Z through the -Y toward the -Z direction, the nightside cells disappeared and the dawn cell in the reversed pair wrapped around and displaced the dusk cell until a conventional two-cell pattern was reestablished, largely in accord with the qualitative model of Crooker [1988]. Our results suggest that multiple cells can arise as a result of strong southward to northward transitions in the IMF. They appear to persist for sometime thereafter. C1 NATL CTR ATMOSPHER RES,HIGH ALTITUDE OBSERV,BOULDER,CO 80307. GEOPHYS LAB,DIV SPACE PHYS,WASHINGTON,DC. SRI INT,MENLO PK,CA 94025. NASA,DIV SPACE PHYS,WASHINGTON,DC 20546. NOAA,NATL GEOPHYS DATA CTR,BOULDER,CO 80303. RP KNIPP, DJ (reprint author), USAF ACAD,DEPT PHYS,COLORADO SPRINGS,CO 80840, USA. NR 20 TC 56 Z9 56 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR PY 1991 VL 18 IS 4 BP 721 EP 724 DI 10.1029/90GL02592 PG 4 WC Geosciences, Multidisciplinary SC Geology GA FG828 UT WOS:A1991FG82800037 ER PT J AU CLARKE, WB DOWNING, RG AF CLARKE, WB DOWNING, RG TI DETERMINATION OF LITHIUM IN 13 GEOCHEMICAL REFERENCE MATERIALS BY THERMAL-NEUTRON CAPTURE AND HE-3 MASS-SPECTROMETRY SO GEOSTANDARDS NEWSLETTER LA English DT Article ID HE-3; ACTIVATION; BERYLLIUM; BORON; ROCKS AB Thirteen geochemical reference standards have been analysed for lithium by a technique originally developed for assay of lithium in biological materials. The technique consists of thermal neutron irradiation, then measurement of He-3 from decay of H-3 produced via the reaction Li-6(n,alpha)H-3. The results are compared with literature values. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP CLARKE, WB (reprint author), MCMASTER UNIV,DEPT PHYS,HAMILTON L8S 4K1,ONTARIO,CANADA. NR 17 TC 2 Z9 2 U1 1 U2 1 PU GEOSTANDARDS PI VANDOEUVRE NANCY PA 15 RUE NOTRE-DAME-DES-PAUVRES BP 20, 54501 VANDOEUVRE NANCY, FRANCE SN 0150-5505 J9 GEOSTANDARD NEWSLETT JI Geostand. Newsl. PD APR PY 1991 VL 15 IS 1 BP 121 EP 124 DI 10.1111/j.1751-908X.1991.tb00102.x PG 4 WC Geosciences, Multidisciplinary SC Geology GA FJ243 UT WOS:A1991FJ24300014 ER PT J AU PHILLIPS, WD LETT, PD ROLSTON, SL TANNER, CE WATTS, RN WESTBROOK, CI SALOMON, C DALIBARD, J CLAIRON, A GUELLATI, S AF PHILLIPS, WD LETT, PD ROLSTON, SL TANNER, CE WATTS, RN WESTBROOK, CI SALOMON, C DALIBARD, J CLAIRON, A GUELLATI, S TI OPTICAL MOLASSES - COLD ATOMS FOR PRECISION-MEASUREMENTS SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID MULTILEVEL ATOMS; DOPPLER LIMIT; LASER; SPECTROSCOPY; COLLISIONS; RADIATION AB Reduction of atomic kinetic motion by laser cooling has important applications to atomic frequency standards and other precision measurements. The optical molasses technique, used for cooling neutral atoms, has produced temperatures below 3-mu-K for cesium atoms, corresponding to an rms velocity of about 13 mm/s. This is considerably lower than the lower limit originally thought to apply to laser cooling and is apparently the lowest kinetic temperature ever measured for three-dimensional cooling. New laser cooling mechanism have been identified to explain the low temperatures. C1 LAB PRIMAIRE TEMPS & FREQUENCES,F-75014 PARIS,FRANCE. LAB AIMEE COTTON,F-91405 ORSAY,FRANCE. ECOLE NORM SUPER,SPECTROSCOPIE HERTZIENNE LAB,F-75231 PARIS 05,FRANCE. RP PHILLIPS, WD (reprint author), NATL INST STAND & TECHNOL,CTR ATOM MOLEC & OPT PHYS,PHY B160,GAITHERSBURG,MD 20899, USA. RI Westbrook, Christoph/B-6092-2009; rolston, steven/L-5175-2013; Dalibard, Jean/M-5648-2015 OI Westbrook, Christoph/0000-0002-6490-0468; rolston, steven/0000-0003-1671-4190; Dalibard, Jean/0000-0001-8469-3913 NR 31 TC 2 Z9 2 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 78 EP 80 DI 10.1109/TIM.1990.1032887 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400003 ER PT J AU TAYLOR, BN AF TAYLOR, BN TI THE POSSIBLE ROLE OF THE FUNDAMENTAL CONSTANTS IN REPLACING THE KILOGRAM SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID GYROMAGNETIC RATIO; STANDARDS; QUANTUM; PROTON; FIELD; VOLT AB This paper summarizes how appropriate combinations of the values of readily measured and defined fundamental physical constants may eventually lead to the replacement of the international prototype of the kilogram as the unit of mass in the International System of Units or SI. These constants include the Rydberg, fine-structure, Josephson, von Klitzing, Avogadro, and Planck constants. RP TAYLOR, BN (reprint author), NATL INST STAND & TECHNOL,BLDG 221,RM B160,GAITHERSBURG,MD 20899, USA. NR 28 TC 70 Z9 72 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 86 EP 91 DI 10.1109/TIM.1990.1032889 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400005 ER PT J AU DESLATTES, RD KESSLER, EG AF DESLATTES, RD KESSLER, EG TI STATUS OF A SILICON LATTICE MEASUREMENT AND DISSEMINATION EXERCISE SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID PRECISION-MEASUREMENTS; AVOGADRO CONSTANT; INTERFEROMETRY; PARAMETERS; COMPARATOR; LENGTH AB Although no longer explicitly directed toward measurement of the Avogadro constant, we continue significant effort on lattice period measurement in monocrystalline silicon. There are currently operating an upgraded x-ray/optical interferometer and a recently established lattice comparator. We report the status of measurements with these two instruments. RP DESLATTES, RD (reprint author), NATL INST STANDARDS & TECHNOL,PHYS A141,GAITHERSBURG,MD 20899, USA. NR 21 TC 21 Z9 21 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 92 EP 97 DI 10.1109/TIM.1990.1032890 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400006 ER PT J AU BOLLINGER, JJ HEINZEN, DJ ITANO, WM GILBERT, SL WINELAND, DJ AF BOLLINGER, JJ HEINZEN, DJ ITANO, WM GILBERT, SL WINELAND, DJ TI A 303-MHZ FREQUENCY STANDARD BASED ON TRAPPED BE+ IONS SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID GROUND-STATE; PLASMA AB A 303-MHz hyperfine transition in the ground state of Be-9+ was used as a basis of a frequency standard. The ions were stored in a Penning ion trap. Linewidths as narrow as 900-mu-Hz were obtained. The frequency stability was measured to be better than 3 x 10(-12)tau-1/2. The inaccuracy in the second-order Doppler shift was reduced to 5 parts in 10(15) by laser cooling. An apparent pressure shift with an unexpectedly large value was discovered which limits the accuracy of the current experiment to approximately 1 part in 10(13). RP BOLLINGER, JJ (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 17 TC 128 Z9 128 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 126 EP 128 DI 10.1109/TIM.1990.1032897 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400013 ER PT J AU DRULLINGER, RE GLAZE, DJ LOWE, JL SHIRLEY, JH AF DRULLINGER, RE GLAZE, DJ LOWE, JL SHIRLEY, JH TI THE NIST OPTICALLY PUMPED CESIUM FREQUENCY STANDARD SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID BEAM AB The National Institute of Standards and Technology is developing an optically pumped, cesium-beam primary frequency standard. The design follows from an analysis of systematic errors found in cesium beam standards. The details of the design, performance of major subsystems, and preliminary tests of the standard are presented. RP DRULLINGER, RE (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. NR 15 TC 14 Z9 14 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 162 EP 164 DI 10.1109/TIM.1990.1032906 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400022 ER PT J AU HAMILTON, CA KAUTZ, RL STIEG, M CHIEH, K AVRIN, WF SIMMONDS, MB AF HAMILTON, CA KAUTZ, RL STIEG, M CHIEH, K AVRIN, WF SIMMONDS, MB TI A 24-GHZ JOSEPHSON ARRAY VOLTAGE STANDARD SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB A Josephson array voltage standard that operates at 24 GHz has been designed and fabricated. Optimum selection of junction parameters makes possible step stability times of 20 min, which are more than adequate for calibrations at 1 V. Designs using both probe and finline microwave couplers were tested. The probe coupler was about 3 dB more efficient and allowed a smaller chip and a less expensive mount. The reduced operating frequency allows substantial advantages in cost and reliability over more conventional devices that operate at 70-100 GHz. C1 QUANTUM DESIGN INC,SAN DIEGO,CA 92121. RP HAMILTON, CA (reprint author), NATL INST STAND TECHNOL,BOULDER,CO 80303, USA. NR 6 TC 16 Z9 16 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 301 EP 304 DI 10.1109/TIM.1990.1032944 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400060 ER PT J AU STEINER, RL ASTALOS, RJ AF STEINER, RL ASTALOS, RJ TI IMPROVEMENTS FOR AUTOMATING VOLTAGE CALIBRATIONS USING A 10-V JOSEPHSON ARRAY SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID SERIES-ARRAY; STANDARDS AB A voltage standard system based on a 10-V Josephson array been completely automated with three novel developments. First, a unique way of connecting Zener voltage standards, a digital voltmeter (DVM), and the array to a commercial standard cell scanner has provided necessary switching flexibility. Second, using a programmable millimeter wave attenuator has greatly simplified the selection of voltage steps. Third and last, programmed error checking, which verifies array steps by comparing measurement scatter to previously characterized system noise levels, has proven more reliable than visual observation. The operation of this new system is simplified enough for an inexpert user while the calibration uncertainty (1-sigma) is still a few parts in 10(8). RP STEINER, RL (reprint author), NATL INST STANDARDS & TECHNOL,DIV ELECT,GAITHERSBURG,MD 20899, USA. NR 7 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 321 EP 325 DI 10.1109/TIM.1990.1032949 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400065 ER PT J AU KINARD, JR LIPE, TE CHILDERS, CB AF KINARD, JR LIPE, TE CHILDERS, CB TI AC-DC DIFFERENCE RELATIONSHIPS FOR CURRENT SHUNT AND THERMAL CONVERTER COMBINATIONS SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB This paper describes the relationship between the overall ac-dc difference of a current-shunt/thermal-converter combination and the individual characteristics of the current shunt and thermal converter (TC) considered separately. Equations governing these characteristics are derived for the general case where the characteristics include mutual inductance between the shunt and the TC circuits, and for the simplified case such as the replacement of just a thermoelement (TE) within the TC, where the change in mutual inductance is negligible. Predicted and measured results are given for shunts used with different TC's. RP KINARD, JR (reprint author), NATL INST STAND & TECHNOL,DIV ELECT,GAITHERSBURG,MD 20899, USA. NR 2 TC 18 Z9 18 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 352 EP 355 DI 10.1109/TIM.1990.1032958 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400074 ER PT J AU HUANG, DX KINARD, JR REBULDELA, G AF HUANG, DX KINARD, JR REBULDELA, G TI RF-DC DIFFERENCES OF THERMAL VOLTAGE CONVERTERS ARISING FROM INPUT CONNECTORS SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB The RF-dc differences of thermal voltage converters (TVC's) caused by skin effect and transmission-line effects of different length input structures have been studied. Some discrepancies do exist between simple mathematical models and measured results for commonly used input connectors. This paper reports a study of these discrepancies and some worst-case results of changes in RF-dc difference due to connection and disconnection of TVC's. C1 NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303. RP HUANG, DX (reprint author), NATL INST STAND & TECHNOL,DIV ELECT,GAITHERSBURG,MD 20899, 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 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 360 EP 365 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400076 ER PT J AU OLDHAM, NM HENDERSON, RM AF OLDHAM, NM HENDERSON, RM TI NEW LOW-VOLTAGE STANDARDS IN THE DC TO 1-MHZ FREQUENCY-RANGE SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID AC AB Two new instruments for generating and measuring 1-200-mV signals have been developed and used to test a number of different low-voltage measurement techniques. Differences between the various measurement methods at 100 mV are typically within +/- 20 ppm in the 1-20 kHz range and within +/- 300 ppm out to 1 MHz. C1 JOHN FLUKE MFG CO,EVERETT,WA 98206. RP OLDHAM, NM (reprint author), NATL INST STAND TECHNOL,DIV ELECT,GAITHERSBURG,MD 20899, USA. NR 9 TC 10 Z9 10 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 368 EP 372 DI 10.1109/TIM.1990.1032962 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400078 ER PT J AU WALTRIP, BC OLDHAM, NM AF WALTRIP, BC OLDHAM, NM TI PERFORMANCE EVALUATION OF A NEW AUDIO-FREQUENCY POWER BRIDGE SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID CALIBRATION; WATTMETER; SYSTEM AB Several techniques for measuring active and reactive power in the 50 Hz to 20 kHz frequency range are described. The approaches include: 1) the development of a high-precision sampling wattmeter using a resistive attenuator, a shunt, and two commercially available sampling voltmeters configured as a dual-channel equivalent-time sampler; 2) the development of another high-precision sampling wattmeter using the same shunt and attenuator, a high-impedance, wideband differential amplifier, and a commercially available, dual-channel, direct-sampling waveform analyzer; 3) for zero power factor measurements, the use of a digital generator to produce precise phase shifts from +pi/2 to -pi/2; and 4) the use of simultaneous thermal voltage and current measurements for unity power factor measurements. These approaches were developed to evaluate a new high-accuracy, audio-frequency power bridge that is based on ac voltage and impedance measurements. RP WALTRIP, BC (reprint author), NATL INST STAND & TECHNOL, DIV ELECT, GAITHERSBURG, MD 20899 USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9456 EI 1557-9662 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 380 EP 383 DI 10.1109/TIM.1990.1032965 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400081 ER PT J AU FILIPSKI, PS SO, E MOORE, WJM KNIGHT, RBD MARTIN, P OLDHAM, NM WALTRIP, BC AF FILIPSKI, PS SO, E MOORE, WJM KNIGHT, RBD MARTIN, P OLDHAM, NM WALTRIP, BC TI AN INTERNATIONAL COMPARISON OF LOW AUDIO FREQUENCY POWER-METER CALIBRATIONS CONDUCTED IN 1989 SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID COMPARATOR AB The results of an intercomparison of low audio-frequency power meter calibrations conducted in 1989 among the National Research Council, Canada; the National Physical Laboratory, United Kingdom; and the National Institute of Standards and Technology, USA, are described. A time-division wattmeter, developed at the National Research Council, was used as the transfer standard. The measurements were made at 120 V, 5 A, power factors of 1, 0 lead, and 0 lag and at frequencies up to 5 kHz. Agreement between the NPL and NRC laboratories was better than 96 ppm in the 60-1600 Hz range, and better than 74 ppm between NIST and NRC in the 50-4800 Hz range. C1 NATL PHYS LAB,TEDDINGTON TW11 0LW,MIDDX,ENGLAND. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP FILIPSKI, PS (reprint author), NATL RES COUNCIL CANADA,DEPT ELECT ENGN,OTTAWA K1A 0R8,ONTARIO,CANADA. NR 6 TC 6 Z9 6 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 399 EP 402 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400086 ER PT J AU RAMBOZ, JD WEST, JL AF RAMBOZ, JD WEST, JL TI WATT TRANSFER STANDARD SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID POWER AB The use of a time-division multiplier power meter as a watt transfer standard between the National Institute of Standards and Technology (NIST) and an industry standards laboratory is described. Measurements of power at 120 and 240 V, 5 A, 50 and 62 Hz, and at power factors of unity and zero lagging are described. After the unit of power was transferred to the industrial laboratory, a comparison of the laboratory and NIST calibrations indicated an agreement to within 14 parts per million (ppm). Measurements at NIST to assess long-term stability (one year) indicated differences between two power meters of the type being discussed was not in excess of 11 ppm. C1 ROTEK INSTRUMENT CORP,WALTHAM,MA 02154. RP RAMBOZ, JD (reprint author), NATL INST STAND & TECHNOL,DIV ELECT,GAITHERSBURG,MD 20899, USA. NR 4 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 403 EP 405 DI 10.1109/TIM.1990.1032971 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400087 ER PT J AU RAMBOZ, JD FENIMORE, CP SCHILLER, SB AF RAMBOZ, JD FENIMORE, CP SCHILLER, SB TI PRECISION QUALIFICATION OF WATTHOUR METERS SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB One of the NIST Measurement Assurance Programs [1] transfers the unit of the watthour using transport meters. For this application the response of these meters to variations in environmental conditions must be well-characterized. A statistically planned experiment is employed to determine corrections for the response of each meter to varying conditions of voltage, current, temperature, and power factor. This qualification procedure is designed to be efficient with the number of test points and to yield estimates of the model parameters describing the corrections. RP RAMBOZ, JD (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 406 EP 409 DI 10.1109/TIM.1990.1032972 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400088 ER PT J AU WAIT, D ENGEN, GF AF WAIT, D ENGEN, GF TI APPLICATION OF RADIOMETRY TO THE ACCURATE MEASUREMENT OF AMPLIFIER NOISE SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID MICROWAVE AB In response to the requirements of the microwave community which we serve, a calibration service for amplifier noise is under development at the National Institute of Standards and Technology (NIST). This paper includes a review and makes certain extensions to the associated theory from the scattering matrix context. The application of the (highly developed) NIST radiometers to the measurement problem is then outlined, and a preliminary assessment of the probable accuracy is given. RP WAIT, D (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 27 TC 26 Z9 26 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 433 EP 437 DI 10.1109/TIM.1990.1032979 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400095 ER PT J AU WAIT, DF COUNAS, GJ KESSEL, W BUCHHOLZ, FI AF WAIT, DF COUNAS, GJ KESSEL, W BUCHHOLZ, FI TI PTB-NIST BILATERAL COMPARISON OF MICROWAVE NOISE POWER IN COAXIAL TRANSMISSION-LINE SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID STANDARD; RANGE AB The Physikalisch-Technische Bundesanstalt (PTB) and the National Institute of Standards and Technology (NIST) have compared microwave noise power in coaxial transmission lines. This intercomparison is of particular metrological interest as both laboratories have independently developed coaxial primary thermal noise standards using different technologies: a hot standard at PTB and cold standards at NIST. Different types of comparison radiometers are operating at each laboratory: a total power radiometer at NIST and an RF-switched radiometer with IF-attenuator at PTB. Each laboratory measured two solid state noise sources at 2.0, 4.0, and 8.0 GHz relative to their primary thermal noise standards. The agreement between both laboratories is better than 0.05 dB. C1 PHYS TECH BUNDESANSTALT,W-3300 BRAUNSCHWEIG,GERMANY. RP WAIT, DF (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET FIELDS,BOULDER,CO 80303, USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 449 EP 454 DI 10.1109/TIM.1990.1032983 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400099 ER PT J AU WEISS, MA WEISSERT, TP AF WEISS, MA WEISSERT, TP TI TA2, A TIME SCALE ALGORITHM FOR POST-PROCESSING - AT1 PLUS FREQUENCY VARIANCE SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article AB In time-scale applications which do not require a real-time output, one can use a post-processing algorithm to take advantage of improved characterization of clocks in the scale and the capability for frequency-step detection to improve the long-term performance of the scale. We describe a post-processing time-scale algorithm which is under study at the National Institute of Standards and Technology. We report preliminary results from analysis of both simulated and real clocks. The post-processing algorithm improves the estimate of time and frequency offsets of simulated clocks from the ensemble and, when applied to real clocks, it improves the long-term stability of the time scale over that generated by the single-pass frequency-step detecting algorithm, AT2. RP WEISS, MA (reprint author), NATL INST STAN & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD APR PY 1991 VL 40 IS 2 BP 496 EP 501 DI 10.1109/TIM.1990.1032995 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA FN074 UT WOS:A1991FN07400111 ER PT J AU Hefner, AR AF Hefner, Allen R., Jr. TI An Investigation of the Drive Circuit Requirements for the Power Insulated Gate Bipolar Transistor (IGBT) SO IEEE TRANSACTIONS ON POWER ELECTRONICS LA English DT Article AB The drive circuit requirements of the IGBT are explained with the aid of an analytical model. It is shown that non-quasi-static effects limit the influence of the drive circuit on the time rate-of-change of anode voltage. Model results are compared with measured turn-on and turn-off waveforms for different drive, load, and feedback circuits and for different IGBT base lifetimes. C1 [Hefner, Allen R., Jr.] NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. RP Hefner, AR (reprint author), NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. NR 14 TC 62 Z9 67 U1 0 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0885-8993 EI 1941-0107 J9 IEEE T POWER ELECTR JI IEEE Trans. Power Electron. PD APR PY 1991 VL 6 IS 2 BP 208 EP 219 DI 10.1109/63.76807 PG 12 WC Engineering, Electrical & Electronic SC Engineering GA V43AD UT WOS:000209653400006 ER PT J AU READ, DT PFUFF, M AF READ, DT PFUFF, M TI POTENTIAL DROP IN THE CENTER-CRACKED PANEL WITH ASYMMETRIC CRACK EXTENSION SO INTERNATIONAL JOURNAL OF FRACTURE LA English DT Article AB The well-known Johnson formula relates the electrical potential drop across a symmetric center crack in a current-carrying tensile panel to the crack length. To allow individual measurement of the crack growth at both ends of such a crack, the potential measured between contact points located on opposite sides and equidistant from the panel center line has been studied. Because this potential must ideally be identically zero for symmetric crack growth, it is termed the asymmetric potential. Its sign and magnitude are related to the direction and extent of asymmetric crack growth. It was found that contact points directly above the ends of the initial symmetric crack provide a signal which is well-suited to the determination of the asymmetry of the crack extension. This information is complementary to the total crack length information obtained using the Johnson formula. Experimental measurements and theoretical results were used to produce calibration formulae relating the asymmetric potential to the asymmetry of the crack dimensions in center-cracked panels. C1 NBS,DIV FRACTURE & DEFORMAT,BOULDER,CO 80303. RP READ, DT (reprint author), GKSS FORSCHUNGSZENTRUM GEESTHACHT GMBH,W-2054 GEESTHACHT,GERMANY. NR 4 TC 5 Z9 5 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0376-9429 J9 INT J FRACTURE JI Int. J. Fract. PD APR 1 PY 1991 VL 48 IS 3 BP 219 EP 229 DI 10.1007/BF00036633 PG 11 WC Materials Science, Multidisciplinary; Mechanics SC Materials Science; Mechanics GA FK780 UT WOS:A1991FK78000005 ER PT J AU FRASER, GT AF FRASER, GT TI (H2O)2 - SPECTROSCOPY, STRUCTURE AND DYNAMICS SO INTERNATIONAL REVIEWS IN PHYSICAL CHEMISTRY LA English DT Article ID INFRARED PREDISSOCIATION SPECTRA; ROTATION-TUNNELING SPECTRUM; HYDROGEN-FLUORIDE DIMER; WATER DIMER; MOLECULAR-BEAM; VIBRATIONAL PREDISSOCIATION; LASER SPECTROSCOPY; AMMONIA DIMER; ENERGY-LEVELS; HCL DIMER AB Tunnelling in water dimer allows each of the hydrogen atoms to participate in the hydrogen bonding, giving rise to a complicated energy-level scheme and rotational spectrum. As a result of new theoretical and experimental developments, great progress has been made in the analysis and interpretation of this spectrum, yielding detailed information about this hydrogen-bonded interaction. This paper reviews the spectroscopy of this highly non-rigid dimer, which is becoming a prototype systems for the study of multidimensional tunnelling problems in weakly bound complexes. RP FRASER, GT (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 57 TC 127 Z9 127 U1 3 U2 14 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0144-235X J9 INT REV PHYS CHEM JI Int. Rev. Phys. Chem. PD APR-JUN PY 1991 VL 10 IS 2 BP 189 EP 206 DI 10.1080/01442359109353257 PG 18 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA EW877 UT WOS:A1991EW87700002 ER PT J AU SMITH, JA KRAJEWSKI, WF AF SMITH, JA KRAJEWSKI, WF TI ESTIMATION OF THE MEAN FIELD BIAS OF RADAR RAINFALL ESTIMATES SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID SURFACE RAINFALL AB In this paper procedures are developed for estimating the mean field bias of radar rainfall estimates. Mean field bias is modeled as a random process that varies not only from storm to storm but also over the course of a storm. State estimates of mean field bias are based on hourly raingage data and hourly accumulations of radar rainfall estimates. The procedures are developed for the precipitation processing systems used with products of the Next Generation Weather Radar (NEXRAD) system. To implement the state estimation procedures, parameters of the bias model must be specified. Likelihood-based procedures are developed for estimating these parameters. A simulation experiment is carried out to assess performance of the parameter estimation procedure. Convergence of parameter estimators is rapid for the cases studied, with data from approximately 25 storms providing parameter estimates of acceptable accuracy. The state estimation procedures are applied to radar and raingage data from the 27 May 1987 storm, which was centered near the NSSL radar in Norman, Oklahoma. The results highlight dependence of the state estimation problem on the parameter estimation problem. C1 NOAA,NATL WEATHER SERV,HYDROL RES LAB,SILVER SPRING,MD 20910. UNIV IOWA,DEPT CIVIL & ENVIRONM ENGN,IOWA INST HYDRAUL RES,IOWA CITY,IA 52242. RP SMITH, JA (reprint author), PRINCETON UNIV,SCH ENGN APPL SCI,DEPT CIVIL ENGN & OPERAT RES,PRINCETON,NJ 08544, USA. NR 38 TC 132 Z9 134 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD APR PY 1991 VL 30 IS 4 BP 397 EP 412 DI 10.1175/1520-0450(1991)030<0397:EOTMFB>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FL199 UT WOS:A1991FL19900001 ER PT J AU WITT, A NELSON, SP AF WITT, A NELSON, SP TI THE USE OF SINGLE-DOPPLER RADAR FOR ESTIMATING MAXIMUM HAILSTONE SIZE SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID HAIL GROWTH; STORM; MODEL; FLOW AB The relationship between a storm's divergent outflow magnitude at upper levels and maximum hailstone size was investigated by analyzing single-Doppler radar data for 49 severe hailstorms. Two different techniques were developed for use with single-Doppler radar data to estimate the magnitude of divergent outflows. The developed techniques show considerable skill at estimating the maximum hailstone size produced by a thunderstorm, with the correlation coeffients between the parameters used and maximum hailstone size being as high as 0.89. The data also show that estimates of maximum hailstone size have an 80% chance of being accurate to within +/- 1.4 cm. The developed techniques are computationally simple and should be useful for real-time estimation of the maximum hailstone size likely to be produced by a thunderstorm. C1 NATL SCI FDN,WASHINGTON,DC 20550. RP WITT, A (reprint author), NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 40 TC 14 Z9 15 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD APR PY 1991 VL 30 IS 4 BP 425 EP 431 DI 10.1175/1520-0450(1991)030<0425:TUOSDR>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FL199 UT WOS:A1991FL19900003 ER PT J AU MCMILLIN, LM AF MCMILLIN, LM TI EVALUATION OF A CLASSIFICATION METHOD FOR RETRIEVING ATMOSPHERIC TEMPERATURES FROM SATELLITE MEASUREMENTS SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article AB The retrieval of vertical temperature profiles from radiances measured from a satellite is a difficult inversion problem that has been solved to varying degrees of accuracy by several approaches. A method that uses a classification approach is for the initial estimate is described. The initial estimate is modified by the application of a single set of regression coefficients that is valid for all latitudes and seasons. Retrievals from this method are compared to the operational retrievals obtained by the National Environmental Satellite, Data, and Information Service (NESDIS). The comparison is based on the carefully matched radiosonde-retrieval pairs that are used in the operational system to update retrieval coefficients. About 10% of the data covering the period July 1987-July 1988 was used to generate the coefficients for both the classification and the retrieval that are used in the classification method. The classification method was then used to process data covering the period July 1987-July 1989. Results from about 100 000 soundings covering the two-year period show the classification method to be consistently (0.2-0.3 K rms) better than the operational method in the lower atmosphere, the region for which the classification was optimized, and slightly was near 100 hPa. A significant feature of the evaluation is that all the coefficients used in the classification method were constant for the two years. Most retrieval systems are periodically tuned to agree with radiosondes. Examination of the mean from the classification retrievals produced with fixed coefficients show a slight drift over the two years in the lower atmosphere, a sudden change in the upper atmosphere, (probably due to a change in one or more channels), and seasonal changes in bias at some levels. These effects are diminished in the operational results because the operational coefficients are adjusted to agree with radiosonde reports once a week. The increase in accuracy of the classification retrievals over the operational ones could be enhanced by updating the class means using a procedure similar to the one currently employed by the operational system. The evaluation period happened to include the time when a major change was made to the operational method and shows a slight improvement in the operational results after the change. RP MCMILLIN, LM (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,SATELLITE RES LAB,WORLD WEATHER BLDG,WASHINGTON,DC 20233, USA. NR 22 TC 10 Z9 10 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD APR PY 1991 VL 30 IS 4 BP 432 EP 446 DI 10.1175/1520-0450(1991)030<0432:EOACMF>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FL199 UT WOS:A1991FL19900004 ER PT J AU EBLE, MC GONZALEZ, FI AF EBLE, MC GONZALEZ, FI TI DEEP-OCEAN BOTTOM PRESSURE MEASUREMENTS IN THE NORTHEAST PACIFIC SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB Pressure transducers with quartz-crystal resonators are being used to measure deep-ocean bottom pressure in the northeast Pacific as part of a long-term monitoring program. In principal, instrument sensitivity is less than 1 mm for sea-level oscillations of periods greater than a few minutes; in practice, however, system resolution is limited by long-term sensor drift and background noise. Data are digitally recorded at a rate of 64 samples per hour but selectable intervals ranging from 4 to 128 samples per hour are possible. The field program has focused on the maintenance of five permanent stations in the northeast Pacific since 1986. During this time, phenomena over a wide range of time scales have been recorded, including tides and the seismic surface waves and tsunamis generated by three earthquakes in the Alaskan Bight. RP EBLE, MC (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,BLDG 3,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 0 TC 32 Z9 33 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD APR PY 1991 VL 8 IS 2 BP 221 EP 233 DI 10.1175/1520-0426(1991)008<0221:DOBPMI>2.0.CO;2 PG 13 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA FL197 UT WOS:A1991FL19700002 ER PT J AU HONG, YC WANG, JT HONG, CY BROWN, WE CHOW, LC AF HONG, YC WANG, JT HONG, CY BROWN, WE CHOW, LC TI THE PERIAPICAL TISSUE-REACTIONS TO A CALCIUM-PHOSPHATE CEMENT IN THE TEETH OF MONKEYS SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article ID ROOT-CANAL SEALER; SETTING CEMENT AB A calcium phosphate cement, Grossman sealer, and Sargenti N2 were compared under conditions where root canals of monkey incisors were deliberately overfilled and the apical tissue responses were evaluated histologically. The periapical tissues exposed to Sargenti N2 revealed severe irritation at all times through the 6-month experimental period. The reactions to Grossman sealer were milder but persisted throughout the observation period. The calcium-phosphate-cement treated animals showed mild tissue irritation after 1 month, but thereafter the adverse tissue reactions were minimal. New bone formation adjacent to the cement was also observed. These results point to the possibility that calcium phosphate cement might be used in simplified endodontic procedures. The compatibility of calcium phosphate cement with the periapical tissue suggests that the cement may have other applications in dentistry and medicine. C1 NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899. RP HONG, YC (reprint author), NATL TAIWAN UNIV,COLL MED,SCH DENT,TAIPEI,TAIWAN. NR 18 TC 72 Z9 77 U1 1 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD APR PY 1991 VL 25 IS 4 BP 485 EP 498 DI 10.1002/jbm.820250406 PG 14 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA FB981 UT WOS:A1991FB98100005 PM 2050712 ER PT J AU MURRAY, BT CORIELL, SR MCFADDEN, GB AF MURRAY, BT CORIELL, SR MCFADDEN, GB TI THE EFFECT OF GRAVITY MODULATION ON SOLUTAL CONVECTION DURING DIRECTIONAL SOLIDIFICATION SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID BINARY ALLOY; STABILITY; FLOWS; CYLINDER; MELT AB During directional solidification of a binary alloy at constant velocity, thermosolutal convection may occur due to the temperature and solute gradients associated with the solidification process. For vertical growth in an ideal furnace (lacking horizontal gradients) a quiescent state is possible. For a range of processing conditions, the thermal Rayleigh number is sufficiently small that the stabilizing role of the thermal field during growth vertically upwards may be neglected, and only solutal convection need be considered. The effect of a time-periodic vertical gravitational acceleration (or equivalently vibration) on the onset of solutal convection is calculated based on linear stability using Floquet theory. We find that a stable base state can be destabilized due to modulation, while an unstable state can be stabilized. The flow and solute disturbance fields show both synchronous and subharmonic temporal response to the driving sinusoidal modulation. RP MURRAY, BT (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 24 TC 31 Z9 31 U1 0 U2 0 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 APR PY 1991 VL 110 IS 4 BP 713 EP 723 DI 10.1016/0022-0248(91)90628-I PG 11 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA FL021 UT WOS:A1991FL02100009 ER PT J AU CHANCE, KV JENNINGS, DA EVENSON, KM VANEK, MD NOLT, IG RADOSTITZ, JV PARK, K AF CHANCE, KV JENNINGS, DA EVENSON, KM VANEK, MD NOLT, IG RADOSTITZ, JV PARK, K TI PRESSURE BROADENING OF THE 118.455 CM-1 ROTATIONAL LINES OF OH BY H-2, HE, N2, AND O2 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID BEAM ELECTRIC RESONANCE; HYDROXYL; SPECTRUM; SPECTROSCOPY; TRANSITIONS; OD; CO C1 NATL INST STAND & TECHNOL,WASHINGTON,DC. NASA,LANGLEY RES CTR,HAMPTON,VA 23665. UNIV OREGON,DEPT PHYS,EUGENE,OR 97403. RP CHANCE, KV (reprint author), HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138, USA. OI Chance, Kelly/0000-0002-7339-7577 NR 20 TC 40 Z9 40 U1 1 U2 4 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD APR PY 1991 VL 146 IS 2 BP 375 EP 380 DI 10.1016/0022-2852(91)90012-Y PG 6 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FD466 UT WOS:A1991FD46600012 ER PT J AU GILLIES, JZ GILLIES, CW SUENRAM, RD LOVAS, FJ SCHMIDT, T CREMER, D AF GILLIES, JZ GILLIES, CW SUENRAM, RD LOVAS, FJ SCHMIDT, T CREMER, D TI A MICROWAVE SPECTRAL AND ABINITIO INVESTIGATION OF O3-H2O SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID ELECTRIC-RESONANCE SPECTROSCOPY; PERTURBATION-THEORY; VANDERWAALS MOLECULE; CORRELATION-ENERGY; WATER DIMER; FORCE-FIELD; GAS-PHASE; OZONE; COMPLEXES; STATES C1 RENSSELAER POLYTECH INST, DEPT CHEM, TROY, NY 12180 USA. NATL INST STAND & TECHNOL, DIV MOLEC PHYS, GAITHERSBURG, MD 20899 USA. UNIV COLOGNE, INST ORGAN CHEM, W-5000 COLOGNE 41, GERMANY. GOTHENBURG UNIV, S-41296 GOTHENBURG, SWEDEN. RP GILLIES, JZ (reprint author), SIENA COLL, DEPT CHEM, LOUDONVILLE, NY 12211 USA. NR 42 TC 47 Z9 47 U1 1 U2 8 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD APR PY 1991 VL 146 IS 2 BP 493 EP 512 DI 10.1016/0022-2852(91)90020-B PG 20 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA FD466 UT WOS:A1991FD46600020 ER PT J AU KACKER, RN LAGERGREN, ES FILLIBEN, JJ AF KACKER, RN LAGERGREN, ES FILLIBEN, JJ TI TAGUCHI FIXED-ELEMENT ARRAYS ARE FRACTIONAL FACTORIALS SO JOURNAL OF QUALITY TECHNOLOGY LA English DT Article DE DESIGN OF EXPERIMENTS; FRACTIONAL FACTORIAL PLANS; ORTHOGONAL ARRAYS; TAGUCHI METHODS ID MAIN-EFFECT PLANS; ASYMMETRICAL FACTORIALS AB Taguchi developed his catalog of orthogonal arrays from mathematical procedures published in well-known English language journals. These arrays evolved as extensions of factorial plans and latin squares. This paper illustrates the fractional factorial nature of Taguchi's two-, three-, four-, and five-element orthogonal arrays. Similarly Taguchi's mixed-element orthogonal arrays define fractionated multi-level factorial plans. Thus Taguchi's orthogonal arrays are an element in the cantinuum of the development and use of statistically planned experiments. RP KACKER, RN (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 24 TC 27 Z9 28 U1 0 U2 0 PU AMER SOC QUALITY CONTROL-ASQC PI MILWAUKEE PA ASQC MEMBERSHIP MANAGER 611 E. WISCONSIN AVENUE, MILWAUKEE, WI 53202 SN 0022-4065 J9 J QUAL TECHNOL JI J. Qual. Technol. PD APR PY 1991 VL 23 IS 2 BP 107 EP 116 PG 10 WC Engineering, Industrial; Operations Research & Management Science; Statistics & Probability SC Engineering; Operations Research & Management Science; Mathematics GA FD768 UT WOS:A1991FD76800005 ER PT J AU HUMMER, DG AF HUMMER, DG TI ASYMPTOTIC EXPANSIONS OF THE KERNEL FUNCTIONS FOR LINE FORMATION WITH CONTINUOUS ABSORPTION SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article AB Asymptotic expressions are obtained for the kernel functions M approximately2(tau, a, beta) and K approximately2(tau, a, beta) appearing in the theory of line formation with complete redistribution over a Voigt profile with damping parameter a, in the presence of a source of continuous opacity parameterized by beta. For a > 0, each coefficient in the asymptotic series is expressed as the product of analytic functions of a and eta = beta-tau-separately. For Doppler broadening, only the leading term can be evaluated analytically. C1 NATL INST STAND & TECHNOL,DIV QUANTUM PHYS,BOULDER,CO 80309. RP HUMMER, DG (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD APR PY 1991 VL 45 IS 4 BP 211 EP 216 DI 10.1016/0022-4073(91)90055-U PG 6 WC Optics; Spectroscopy SC Optics; Spectroscopy GA FA957 UT WOS:A1991FA95700003 ER PT J AU WU, YC KOCH, WF AF WU, YC KOCH, WF TI ABSOLUTE DETERMINATION OF ELECTROLYTIC CONDUCTIVITY FOR PRIMARY STANDARD KCL SOLUTIONS FROM 0-DEGREES-C TO 50-DEGREES-C SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE CELL CONSTANT; CONDUCTANCE; DEMAL; ELECTROLYTIC CONDUCTIVITY; POTASSIUM CHLORIDE; PRIMARY STANDARDS; RESISTANCE; SPECIFIC CONDUCTANCE ID CONDUCTANCE AB An absolute determination of aqueous electrolytic conductivity has been made for primary standards 0.01D and 0.1D (demal) potassium chloride solutions over the temperature range of 0 to 50-degrees-C in 5 degree intervals. A cell with a removable center section of accurately known length and area was used for the measurements. Values were adjusted to be in conformity with the ITS-90 temperature scale. The overall uncertainty over the entire temperature range is estimated to be 0.03%. Values at 25-degrees-C for 0.01D and 0.1D KCl solutions are 0.0014086 and 0.012852 S-cm-1, respectively. C1 NATL INST STANDARDS & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. NR 7 TC 60 Z9 62 U1 1 U2 15 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD APR PY 1991 VL 20 IS 4 BP 391 EP 401 DI 10.1007/BF00650765 PG 11 WC Chemistry, Physical SC Chemistry GA FE956 UT WOS:A1991FE95600003 ER PT J AU RAO, ST KU, JY RAO, KS AF RAO, ST KU, JY RAO, KS TI ANALYSIS OF TOXIC AIR CONTAMINANT DATA CONTAINING CONCENTRATIONS BELOW THE LIMIT OF DETECTION SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article ID PARAMETERS AB Air quality data often contain several observations reported only as below the analytical limit of detection (LOD), resulting in "censored" data sets. Such censored and/or truncated data sets tend to complicate statistical analysis. This paper discusses various procedures for estimating mean concentration and its 95 percent confidence bounds from air contaminant data sets which contain values that are reported as below the LOD. A quantitative approach for assessing the uncertainty inherent in the estimated mean concentration due to (a) presence of values below the LOD in the data set, and (b) natural variability of atmospheric concentration data, is described. The utility of this approach in the analysis and interpretation of ambient pollutant concentration data is demonstrated for both hypothetical and observed singly-censored data sets, and for a multiply-censored, multi-pollutant observed concentration data set. The methodologies discussed here should be particularly useful in verifying compliance with environmental regulations, and in estimating the risks associated with long-term exposure of populations to toxic air contaminants and assessing the uncertainty associated with these estimates. C1 NOAA,AIR RESOURCES LAB,DIV ATMOSPHER TURBULENCE & DIFFUS,OAK RIDGE,TN. RP RAO, ST (reprint author), NEW YORK STATE DEPT ENVIRONM CONSERVAT,DIV AIR RESOURCES,50 WOLF RD,ALBANY,NY 12201, USA. NR 22 TC 14 Z9 14 U1 1 U2 1 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA PO BOX 2861, PITTSBURGH, PA 15230 SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD APR PY 1991 VL 41 IS 4 BP 442 EP 448 PG 7 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA FH760 UT WOS:A1991FH76000009 ER PT J AU JOHNSTON, AD BOWEN, RL AF JOHNSTON, AD BOWEN, RL TI PROTECTIVE COATINGS FOR TOOTH CROWNS SO JOURNAL OF THE AMERICAN DENTAL ASSOCIATION LA English DT Article ID BOND STRENGTH; ENAMEL; DENTIN AB Transfer of technology to the dental office could provide thin polymeric coatings over tooth crowns and accessible root surfaces. These coatings can be prepared from relatively inexpensive, commercially available materials in one-step reactions. When the monomer technique becomes available, it will provide caries protection for all of your patients. RP JOHNSTON, AD (reprint author), NIST,PAFFENBARGER RES CTR,AMER DENT ASSOC,HLTH FDN,POLYMERS PROGRAM,GAITHERSBURG,MD 20899, USA. NR 18 TC 5 Z9 5 U1 0 U2 0 PU AMER DENTAL ASSN PI CHICAGO PA 211 E CHICAGO AVE, CHICAGO, IL 60611 SN 0002-8177 J9 J AM DENT ASSOC JI J. Am. Dent. Assoc. PD APR PY 1991 VL 122 IS 4 BP 49 EP 51 PG 3 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA FF824 UT WOS:A1991FF82400024 PM 2022787 ER PT J AU JAHANMIR, S KENNEDY, FE AF JAHANMIR, S KENNEDY, FE TI TRIBOLOGY EDUCATION - PRESENT STATUS AND FUTURE CHALLENGES - EDITORIAL SO JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME LA English DT Editorial Material C1 DARTMOUTH COLL,HANOVER,NH 03755. RP JAHANMIR, S (reprint author), NAT INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4787 J9 J TRIBOL-T ASME JI J. Tribol.-Trans. ASME PD APR PY 1991 VL 113 IS 2 BP 229 EP 231 DI 10.1115/1.2920610 PG 3 WC Engineering, Mechanical SC Engineering GA FJ111 UT WOS:A1991FJ11100001 ER PT J AU LEDBETTER, H DATTA, S AF LEDBETTER, H DATTA, S TI ELASTIC-CONSTANTS OF A TUNGSTEN-PARTICLE COPPER-MATRIX COMPOSITE SO JSME INTERNATIONAL JOURNAL SERIES I-SOLID MECHANICS STRENGTH OF MATERIALS LA English DT Article DE ELASTIC CONSTANTS; PARTICLE-REINFORCED COMPOSITE; SCATTERED-PLANE-WAVE MODEL; SOUND VELOCITIES; TUNGSTEN-COPPER COMPOSITE AB Using a megahertz-frequency ultrasonic method, we measured the elastic constants of a composite consisting of seventy-volume-percent tungsten particles in a copper matrix. We report the Young, shear, and bulk moduli, and the Poisson ratio. Tungsten is much stiffer than copper: the Young-modulus ratio equals 410/129 = 3.2. Thus, from a linear rule-of-mixture, we expected large departures, which we found. (The Poisson ratio comes close to a linear rule-of-mixture.) Unexpectedly, we found a substantial elastic anisotropy: eighteen percent in the shear modulus. To model the system, we used a scattered-plane-wave ensemble-average approach. For the four elastic constants listed above, we found reasonable model-measurement agreement, one-to-seven percent for the averaged-over-direction measurements. Assuming oblatespheroidal (c/a = 0.5) particles improves the agreement: two percent or less for the four cases. C1 UNIV COLORADO,DEPT MECH ENGN,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP LEDBETTER, H (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,BOULDER,CO 80303, USA. NR 4 TC 2 Z9 2 U1 1 U2 2 PU JAPAN SOC MECHANICAL ENGINEERS SANSHIN HOKUSEI BLDG PI TOKYO PA 4-9 YOYOGI 2-CHOME SHIBUYA-KU, TOKYO 151, JAPAN SN 0914-8809 J9 JSME INT J I-SOLID M PD APR PY 1991 VL 34 IS 2 BP 194 EP 197 PG 4 WC Engineering, Mechanical SC Engineering GA FP412 UT WOS:A1991FP41200012 ER PT J AU RUSSELL, TP ANASTASIADIS, SH MENELLE, A FELCHER, GP SATIJA, SK AF RUSSELL, TP ANASTASIADIS, SH MENELLE, A FELCHER, GP SATIJA, SK TI SEGMENT DENSITY DISTRIBUTION OF SYMMETRICAL DIBLOCK COPOLYMERS AT THE INTERFACE BETWEEN 2 HOMOPOLYMERS AS REVEALED BY NEUTRON REFLECTIVITY SO MACROMOLECULES LA English DT Article ID MULTICOMPONENT POLYMER SYSTEMS; BLOCK COPOLYMERS; MOLECULAR DESIGN; BLENDS; FILMS AB The segment density distribution of symmetric, diblock copolymers of poly(styrene), PS, and poly(methyl methacrylate), PMMA, denoted P(S-b-MMA), were investigated by neutron reflectivity. Selective labeling of either block of the P(S-b-MMA) or of the PS or PMMA with deuterium provided the contrast necessary to isolate the distribution of the segments of the components at the interface. Results from a series of experiments were used to solve a simultaneous set of linear equations that yielded the segment density profiles of the PS and PMMA segments of the homopolymers and copolymers at the interface. It was found that the interface formed between the PS and PMMA segments could be described by a hyperbolic tangent function with an effective width of 75 angstrom. This width is 50% broader than that found between the PS and PMMA homopolymers in the absence of the diblock copolymer and between the PS and PMMA lamellar microdomains of the pure P(S-b-MMA) in the bulk. A significant penetration of the PS and PMMA homopolymers into the interfacial region was also found. The area occupied by the copolymer at the interface between the homopolymers is 30% larger than that of the copolymers in the bulk, lamellar microstructure. C1 ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. NATL INST STAND & TECHNOL, DIV REACTOR RADIAT, GAITHERSBURG, MD 20899 USA. RP RUSSELL, TP (reprint author), IBM CORP, DIV RES, ALMADEN RES CTR, 650 HARRY RD, SAN JOSE, CA 95120 USA. RI Anastasiadis, Spiros/D-2778-2009 OI Anastasiadis, Spiros/0000-0003-0936-1614 NR 31 TC 87 Z9 87 U1 1 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD APR 1 PY 1991 VL 24 IS 7 BP 1575 EP 1582 DI 10.1021/ma00007a020 PG 8 WC Polymer Science SC Polymer Science GA FE892 UT WOS:A1991FE89200020 ER PT J AU DIMARZIO, EA AF DIMARZIO, EA TI STATISTICS OF A POLYMER MOLECULE IN THE PRESENCE OF ASYMMETRIC OBSTACLES SO MACROMOLECULES LA English DT Article ID SELF-AVOIDING-WALKS; CUBIC ANISOTROPIC CRYSTALS; SYSTEMATIC CORRECTIONS; COOPERATIVE PHENOMENA; COHERENT ANOMALIES; DILUTED LATTICES; POROUS-MEDIA; CHAINS; TRANSITION; DYNAMICS AB The number of configurations W(N,z;r,v(r),alpha-i;M,beta-i,x(i)) of a polymer in a field of fixed obstacles is obtained. The cubic lattice of N sites has a coordination number z and is of d = z/2 dimensions. The obstacles are modeled as rigid rods or rigid but bent polymers of length r and of volume fraction upsilon-r. A fraction alpha-i of the obstacle bonds are oriented in orientation i. The flexible polymer which we place into the field of rigid obstacles is of length M, has beta-i of its bonds lying in orientation i, and has an end-to-end-length given by x(i). The formula for W results in expectation values only a few percent different from the exact expressions for the known special cases. The beta-i are not fixed numbers but rather occur with a probability given by W. With the maximum term method the dimensions of the polymer are calculated. The polymer is elongated in the direction of alignment of the obstacles. The volume of the polymer is found to increase with volume fraction of obstacles for isotropically ordered obstacles, but it decreases for high concentrations of obstacles if the obstacles are strongly aligned. The scaling law exponent upsilon describing molecular weight dependence of linear polymer dimension is 0.6 for each of the three dimensions but deviates from this value for large elongation. Seven possible applications of the formula are discussed. RP DIMARZIO, EA (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 48 TC 5 Z9 5 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD APR 1 PY 1991 VL 24 IS 7 BP 1595 EP 1604 DI 10.1021/ma00007a023 PG 10 WC Polymer Science SC Polymer Science GA FE892 UT WOS:A1991FE89200023 ER PT J AU PAULSON, AJ CURL, HC COKELET, ED AF PAULSON, AJ CURL, HC COKELET, ED TI REMOBILIZATION OF CU FROM MARINE PARTICULATE ORGANIC-MATTER AND FROM SEWAGE SO MARINE CHEMISTRY LA English DT Article ID TRACE-METAL BUDGETS; NORTH PACIFIC; PUGET-SOUND; COPPER; ESTUARY; DISTRIBUTIONS; WASTEWATER; TRANSPORT; DISCHARGE; SEDIMENTS AB The possible causes of enrichments of dissolved Cu in the bottom waters of Puget Sound were examined in a series of experiments designed to measure the release of Cu from surface marine organic suspended matter and from sewage-derived particles under ambient conditions. Decomposition of organic matter and ion-exchange controlled the release of about one-third of the Cu bound to large particles (> 53-mu-m). In contrast, no Cu was released from smaller particles (< 53-mu-m) suspended in natural seawater and only 5% of the Cu on small particles was released into artificial seawater with a low dissolved Cu concentration. Within 15 min of mixing primary effluent with natural seawater, 40% of the dissolved Cu was lost from solution by flocculation. Between 15 min and 4 days, 25% of the total effluent Cu was released back into solution. This release could have originated either from particulate Cu on the original sewage particles or from the flocculated Cu that was formed from dissolved Cu within the first 15 min. The release of Cu into the bottom waters of Puget Sound from settling marine organic matter was calculated to have been between 1 and 8-mu-g Cu m-2 day-1, which is comparable with the diffusion of Cu from sediments. In contrast, the release of sewage-derived Cu could have been as high as 725-mu-g Cu m-2 day-1 within 10 km of outfall. RP PAULSON, AJ (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 29 TC 18 Z9 18 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD APR PY 1991 VL 33 IS 1-2 BP 41 EP 60 DI 10.1016/0304-4203(91)90056-3 PG 20 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA FF451 UT WOS:A1991FF45100004 ER PT J AU BRODEUR, RD BAILEY, KM KIM, S AF BRODEUR, RD BAILEY, KM KIM, S TI CANNIBALISM ON EGGS BY WALLEYE POLLOCK THERAGRA-CHALCOGRAMMA IN SHELIKOF STRAIT, GULF OF ALASKA SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article ID EASTERN BERING SEA; DAILY RATION; FISH; CONSUMPTION; PREDATION; ANCHOVY; PALLAS; RATES AB A strong density-dependent relationship has been observed for the walleye pollock Theragra chalcogramma population in the Western Gulf of Alaska. It has been suggested that this relationship may be attributed in part to egg cannibalism by the adult spawning stock. This hypothesis was examined by collecting stomach samples of walleye pollock from the main spawning area over 5 yr. Eggs were prevalent in many stomachs, especially in those from the older age classes. The mean number of eggs in the stomachs was not related to the overall amount of food in the stomach but was linearly related to the density of eggs in the water column. Total egg consumption was estimated for 3 years (1986, 1988, and 1989) and was found to be only a small (<1) percentage of the total egg production. Even during a year (1981) of peak adult abundance, the total calculated egg consumption was less than 3% of the total egg production. A passive filtration model provided estimates similar to those observed in the field. We conclude that egg cannibalism alone would not account for the high egg mortalities observed. C1 NATL MARINE FISHERIES SERV, ALASKA FISHERIES SCI CTR, SEATTLE, WA 98115 USA. NR 32 TC 11 Z9 11 U1 0 U2 2 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 EI 1616-1599 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PD APR PY 1991 VL 71 IS 3 BP 207 EP 218 DI 10.3354/meps071207 PG 12 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA FK526 UT WOS:A1991FK52600001 ER PT J AU SIEWERT, TA AF SIEWERT, TA TI REPORT ON 1990 ACTIONS BY INTERNATIONAL-INSTITUTE-OF-WELDING SO MATERIALS EVALUATION LA English DT Editorial Material RP SIEWERT, TA (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD APR PY 1991 VL 49 IS 4 BP 470 EP 472 PG 3 WC Materials Science, Characterization & Testing SC Materials Science GA FF853 UT WOS:A1991FF85300003 ER PT J AU BENJAMIN, SG BREWSTER, KA BRUMMER, R JEWETT, BF SCHLATTER, TW SMITH, TL STAMUS, PA AF BENJAMIN, SG BREWSTER, KA BRUMMER, R JEWETT, BF SCHLATTER, TW SMITH, TL STAMUS, PA TI AN ISENTROPIC 3-HOURLY DATA ASSIMILATION SYSTEM USING ACARS AIRCRAFT OBSERVATIONS SO MONTHLY WEATHER REVIEW LA English DT Article ID PREDICTION; SURFACE; MODELS AB A 3-h intermittent data assimilation system (Mesoscale Analysis and Prediction System-MAPS) configured in isentropic coordinates was developed and implemented in real-time operation. The major components of the system are data ingest, objective quality control of the observations, objective analysis, and a primitive equation forecast model, all using isentropic coordinates to take advantage of the improved resolution near frontal zones and greater spatial coherence of data that this coordinate system provides. Each 3-h forecast becomes the background for the subsequent analysis; in this manner, a four-dimensional set of observations can be assimilated. The primary asynoptic data source used in current real-time operation of this system is aircraft data, most of it automated. Data from wind profilers, surface observations, and radiosondes are also included in MAPS. Statistics were collected over the last half of 1989 and into 1990 to study the performance of MAPS and compare it with that of the Regional Analysis and Forecast System (RAFS), which is run operationally at the National Meteorological Center (NMC). Analyses generally fit mandatory-level observations more closely in MAPS than in RAFS. Three-hour forecasts from MAPS, incorporating asynoptic aircraft reports, improve on 12-h MAPS forecasts valid at the same time for all levels and variables, and also improve on 12-h RAFS forecasts of upper-level winds. This result is due to the quality and volume of the aircraft data as well as the effectiveness of the isentropic data assimilation used. Forecast fields at other levels are slightly poorer than those from RAFS. This may be largely due to the lack of diabatic and boundary-layer physics for the MAPS model used in this test period. C1 NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. COLORADO STATE UNIV, COOPERAT INST RES ATMOSPHERE, FT COLLINS, CO 80523 USA. RP NOAA, ENVIRONM RES LABS, FORECAST SYST LAB, REFSI, 325 BROADWAY, BOULDER, CO 80303 USA. RI Smith, Tracy/C-7619-2015; Schlatter, Thomas /E-7480-2015; Benjamin, Stan/C-5818-2015 OI Smith, Tracy/0000-0002-7189-4027; Benjamin, Stan/0000-0002-5751-8236 NR 32 TC 84 Z9 85 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD APR PY 1991 VL 119 IS 4 BP 888 EP 906 DI 10.1175/1520-0493(1991)119<0888:AITHDA>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FK704 UT WOS:A1991FK70400002 ER PT J AU MCLAUGHLIN, WL YUNDONG, C SOARES, CG MILLER, A VANDYK, G LEWIS, DF AF MCLAUGHLIN, WL YUNDONG, C SOARES, CG MILLER, A VANDYK, G LEWIS, DF TI SENSITOMETRY OF THE RESPONSE OF A NEW RADIOCHROMIC FILM DOSIMETER TO GAMMA-RADIATION AND ELECTRON-BEAMS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID COLLISION STOPPING POWER; POSITRONS; ELEMENTS AB A new radiation-sensitive imaging material, called GafChromic(TM) Dosimetry Media, offers advances in high-dose radiation dosimetry and high-resolution radiography for gamma radiation and electrons. The potential uses in radiation processing, radiation sterilization of medical devices, population control of insects by irradiation, food irradiation, blood irradiation for organ-transplant immuno-suppression, clinical radiography, and industrial radiography have led to the present sensitometric study over the breadth of the wide dynamic range of this new routine detector and imaging material, namely, absorbed doses from 10 Gy to 5 x 10(4) Gy. The thin-coated film is colorless before irradiation, and registers a deep-blue image upon irradiation, with two absorption bands at about 650 nm (major band) and 600 nm (minor band). The response to electrons, in terms of increase in absorbance per unit absorbed dose, is the same as that to gamma radiation within the estimated uncertainty of the measurements (+/- 5%, 95% confidence level). The spatial resolving power is > 1200 lines/mm. After the first 24 hours, the image is stable over many months (within +/- 5% in absorbance), however, the system should be irradiated and analyzed at approximately the temperatures used during calibration, because of temperature dependence during irradiation and readout, and temperatures greater than 55-degrees-C should be avoided. C1 RISO NATL LAB,DK-4000 ROSKILDE,DENMARK. NORDION INT INC,KANATA K2K 1X8,ONTARIO,CANADA. GAF CHEM CORP,ELECTRON IMAGING PROD,WAYNE,NJ 07470. RP MCLAUGHLIN, WL (reprint author), NATL INST STAND & TECHNOL,CTR RADIAT RES,GAITHERSBURG,MD 20899, USA. NR 16 TC 227 Z9 233 U1 0 U2 9 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 APR 1 PY 1991 VL 302 IS 1 BP 165 EP 176 DI 10.1016/0168-9002(91)90506-L PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FK889 UT WOS:A1991FK88900022 ER PT J AU PERERA, RCC COWAN, PL LINDLE, DW LAVILLA, RE JACH, T DESLATTES, RD AF PERERA, RCC COWAN, PL LINDLE, DW LAVILLA, RE JACH, T DESLATTES, RD TI MOLECULAR-ORBITAL STUDIES VIA SATELLITE-FREE X-RAY-FLUORESCENCE - CL K-ABSORPTION AND K-VALENCE-LEVEL EMISSION-SPECTRA OF CHLOROFLUOROMETHANES SO PHYSICAL REVIEW A LA English DT Article ID SYNCHROTRON RADIATION BEAMLINE; HIGH-ENERGY-RESOLUTION; PHOTOELECTRON-SPECTRA; SPECTROSCOPY; PERFORMANCE; REGION; CF2CL2; CH3CL AB X-ray absorption and emission measurements in the vicinity of the chlorine K edge of the three chlorofluoromethanes have been made using monochromatic synchrotron radiation as the source of excitation. By selectively tuning the incident radiation to just above the Cl 1s single-electron ionization threshold for each molecule, less complex x-ray-emission spectra are obtained. This reduction in complexity is attributed to the elimination of multielectron transitions in the Cl K shell, which commonly produce satellite features in x-ray emission. The resulting "satellite-free" x-ray-emission spectra exhibit peaks due only to electrons in valence molecular orbitals filling a single Cl 1s vacancy. These simplified emission spectra and the associated x-ray absorption spectra are modeled using straightforward procedures and compared with semiempirical ground-state molecular-orbital calculations. Good agreement is observed between the present experimental and theoretical results for valence-orbital energies and those obtained from ultraviolet photoemission, and between relative radiative yields determined both experimentally and theoretically in this work. C1 NATL INST STAND & TECHNOL,DIV QUANTUM METROL,GAITHERSBURG,MD 20899. RP PERERA, RCC (reprint author), UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 25 TC 26 Z9 26 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR 1 PY 1991 VL 43 IS 7 BP 3609 EP 3618 DI 10.1103/PhysRevA.43.3609 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FG216 UT WOS:A1991FG21600047 ER PT J AU THEODOSIOU, CE AF THEODOSIOU, CE TI PREDICTION OF NOVEL MINIMA IN THE DIFFERENTIAL CROSS-SECTIONS OF H- COLLISIONS WITH ATOMS SO PHYSICAL REVIEW A LA English DT Note ID EXCITATION; IMPACT; IONS AB I predict that the differential cross sections for elastic and inelastic scattering of H- with atoms will exhibit sharp minima. These minima result from the cancellation between the contributions to the cross section by the positively charged nucleus and the two negatively charged electrons of H-. The location for such minima is predicted based on a simple first Born approximation, but should be correct at least for intermediate to high impact energies. C1 UNIV TOLEDO,DEPT PHYS & ASTRON,TOLEDO,OH 43606. NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP THEODOSIOU, CE (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD APR 1 PY 1991 VL 43 IS 7 BP 4032 EP 4035 DI 10.1103/PhysRevA.43.4032 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FG216 UT WOS:A1991FG21600089 ER PT J AU GOLDMAN, AI STASSIS, C BELLISSENT, R MOUDDEN, H PYKA, N GAYLE, FW AF GOLDMAN, AI STASSIS, C BELLISSENT, R MOUDDEN, H PYKA, N GAYLE, FW TI INELASTIC-NEUTRON-SCATTERING MEASUREMENTS OF PHONONS IN ICOSAHEDRAL AL-LI-CU SO PHYSICAL REVIEW B LA English DT Note ID QUASICRYSTAL AB Inelastic-neutron-scattering measurements on a single grain of icosahedral Al-Li-Cu are presented. Within experimental error the acoustic-phonon dispersion at small, but finite, q is independent of direction, confirming the isotropic elasticity expected for icosahedral crystals. By following the longitudinal-phonon dispersion curve along a fivefold axis we can identify the location of a "quasi-Brillouin-zone boundary." The measurements also suggest the presence of an optical or localized mode along the twofold axis at approximately 10-11 meV. We compare these results to theoretical calculations for one- and two-dimensional quasiperiodic systems. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. CENS,LAB LEON BRILLOUIN,F-91191 GIF SUR YVETTE,FRANCE. NIST,DIV MET,GAITHERSBURG,MD 20899. RP GOLDMAN, AI (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 12 TC 35 Z9 35 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD APR 1 PY 1991 VL 43 IS 10 BP 8763 EP 8766 DI 10.1103/PhysRevB.43.8763 PN B PG 4 WC Physics, Condensed Matter SC Physics GA FE551 UT WOS:A1991FE55100108 ER PT J AU CRISSMAN, JM AF CRISSMAN, JM TI ON THE LONG-TIME CREEP AND LIFETIME BEHAVIOR IN UNIAXIAL EXTENSION OF A LINEAR LOW-DENSITY POLYETHYLENE SO POLYMER ENGINEERING AND SCIENCE LA English DT Article ID SHEAR MODIFICATION; BLOWN FILMS; POLYMERS AB This paper describes uniaxial creep measurements done on a linear low density polyethylene over a wide range of temperatures and applied stresses. It is found that the creep behavior overall is quite complex and that the one quantity which can best be used to predict useful lifetime of this material is the time at which necking is observed. The time to neck data has been used to generate a composite curve which can serve as an upper bound to lifetime prediction. RP CRISSMAN, JM (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 17 TC 5 Z9 5 U1 1 U2 2 PU SOC PLASTICS ENG INC PI BROOKFIELD CENTER PA 14 FAIRFIELD DR, BROOKFIELD CENTER, CT 06804-0403 SN 0032-3888 J9 POLYM ENG SCI JI Polym. Eng. Sci. PD APR PY 1991 VL 31 IS 8 BP 541 EP 547 DI 10.1002/pen.760310802 PG 7 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA FK162 UT WOS:A1991FK16200001 ER PT J AU KIM, KH BELL, MI DOZIER, CM FREITAG, RK BOULDIN, CE AF KIM, KH BELL, MI DOZIER, CM FREITAG, RK BOULDIN, CE TI CORRECTING FOR X-RAY-ENERGY CALIBRATION ERROR CAUSED BY MISALIGNMENT OF A RIGHT-ANGLE LINKAGE MONOCHROMATOR SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID SYNCHROTRON RADIATION AB Small alignment errors of right-angle linkage monochromators typical to many x-ray absorption fine structure beamlines can cause significant errors in the energy calibrations. A 1-degrees misalignment produces errors greater than 1 keV over the hard x-ray operating range of a typical monochromator. The energy error caused by such misalignments is analyzed and its mathematical form given. The error can be corrected by inverting the expression and the amount of misalignment determined by accurate energy measurements at a few points. The accuracy of the corrections is tested. The effects of this error on x-ray absorption fine structure data and their interpretation are also discussed. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP KIM, KH (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD APR PY 1991 VL 62 IS 4 BP 982 EP 985 DI 10.1063/1.1141988 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FF017 UT WOS:A1991FF01700018 ER PT J AU YEH, T WU, ST AF YEH, T WU, ST TI MODEL-CALCULATIONS OF THE RISING MOTION OF A PROMINENCE LOOP SO SOLAR PHYSICS LA English DT Article ID FLARES AB Model calculations are presented for the rising motion of the top section of a prominence loop, which is represented by a straight flux rope immersed in a coronal medium permeated with a bipolar magnetic field. Initially the prominence is at rest, in equilibrium with the surrounding coronal medium. When the magnetic monopoles that account for the source current for the bipolar field strengthen, the upward hydromagnetic buoyancy force overcomes the downward gravitational force so that the prominence is initiated into rising motion. The illustrative examples show that prominences can move away from the solar surface by the action of the hydromagnetic buoyancy force, which is preponderant with the diamagnetic force due to the current carried by the prominence interacting with the coronal magnetic field produced by the photospheric currents, if the changes in the photospheric magnetic field are sufficiently large. C1 UNIV ALABAMA,CTR SPACE PLASMA & AERON RES,HUNTSVILLE,AL 35899. RP YEH, T (reprint author), NOAA,ENVIRONM RES LABS,SPACE ENVIRONM LAB,BOULDER,CO 80303, USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD APR PY 1991 VL 132 IS 2 BP 335 EP 351 DI 10.1007/BF00152292 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FH729 UT WOS:A1991FH72900011 ER PT J AU DRYER, M SMITH, ZK COATES, AJ JOHNSTONE, AD AF DRYER, M SMITH, ZK COATES, AJ JOHNSTONE, AD TI THE FEBRUARY 1986 SOLAR-ACTIVITY - A COMPARISON OF GIOTTO, VEGA-1, AND IMP-8 SOLAR-WIND MEASUREMENTS WITH MHD SIMULATIONS SO SOLAR PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; INTERPLANETARY SHOCK-WAVES; MAJOR MAGNETIC STORMS; INTERACTION REGIONS; EVENTS; FLARES; DISTURBANCES; PIONEER-10; DISTANCES; ORIGIN AB Large disturbances in the interplanetary medium were observed by several spacecraft during a period of enhanced solar activity in early February 1986. The locations of six solar flares and the spacecraft considered here encompassed more than 100-degrees of heliolongitude. These flares during the minimum of cycle 21 set the stage for an extensive multi-spacecraft comparison performed with a two-dimensional, magnetohydrodynamic (MHD) numerical experiment. The plasma instruments on the European Space Agency (ESA)'s GIOTTO spacecraft, on its way to encounter Comet Halley in March 1986, made measurements of the solar wind for up to 8 hours per day during February. We compare solar wind measurements from the Johnstone Plasma Analyzer (JPA) experiment on GIOTTO with the MHD simulation of the interplanetary medium throughout these events. Using plasma data obtained by the IMP-8 satellite in addition, it appears that an extended period of high solar wind speed is required as well as the simulated flares to represent the interplanetary medium in this case. We also compare the plasma and magnetometer data from VEGA-1 with the MHD simulation. This comparison tends to support an interpretation that the major solar wind changes at both GIOTTO and VEGA-1 on 8 February, 1986 were due to a shock from a W05-degrees solar flare on 6 February, 1986 (06:25 UT). The numerical experiment is considered, qualitatively, to resemble the observations at the former spacecraft, but it has less success at the latter one. C1 MULLARD SPACE SCI LAB,HOLMBURY ST MARY RH5 6NT,SURREY,ENGLAND. RP DRYER, M (reprint author), NOAA,SPACE ENVIRONM LAB,R-E-SE3,BOULDER,CO 80303, USA. RI Coates, Andrew/C-2396-2008; xue, yansheng/A-9712-2012 OI Coates, Andrew/0000-0002-6185-3125; NR 39 TC 12 Z9 12 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD APR PY 1991 VL 132 IS 2 BP 353 EP 371 DI 10.1007/BF00152293 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FH729 UT WOS:A1991FH72900012 ER PT J AU WEI, FS DRYER, M AF WEI, FS DRYER, M TI PROPAGATION OF SOLAR FLARE-ASSOCIATED INTERPLANETARY SHOCK-WAVES IN THE HELIOSPHERIC MERIDIONAL PLANE SO SOLAR PHYSICS LA English DT Article ID IPS OBSERVATIONS; AUGUST 1972; WIND SPEED; DISTURBANCES; SCINTILLATION AB We have analyzed 149 flare-associated shock wave events based on interplanetary scintillation (IPS) observational data. All of the flare-associated shock waves tend to propagate toward the low latitude region near the solar equator for flares that are located in both the solar northern and southern hemispheres. Also, the fastest propagation directions tend toward the heliospheric current sheet near 1 AU. We suggest that this tendency is caused by the dynamic action of near-Sun magnetic forces on the ejected coronal plasma that traverses the helmet-like magnetic topologies near the Sun outward to the classical topology that is essentially parallel to the heliospheric current sheet. C1 NOAA,ENVIRONM RES LABS,SPACE ENVIRONM LAB,BOULDER,CO 80303. RP WEI, FS (reprint author), CTR SPACE SCI & APPL RES,BEIJING 100080,PEOPLES R CHINA. NR 43 TC 41 Z9 56 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD APR PY 1991 VL 132 IS 2 BP 373 EP 394 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA FH729 UT WOS:A1991FH72900013 ER PT J AU MELMED, AJ CAMUS, PP ERNST, N SCHMIDT, WA BOZDECH, G NASCHITZKI, M AF MELMED, AJ CAMUS, PP ERNST, N SCHMIDT, WA BOZDECH, G NASCHITZKI, M TI A DIFFUSION PHENOMENON IN Y-BA-CU-O SUPERCONDUCTORS SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 37TH INTERNATIONAL SYMP ON FIELD EMISSION CY JUL 29-AUG 03, 1990 CL ALBUQUERQUE, NM SP INT FIELD EMISS SOC ID FIELD ELECTRON-EMISSION; ATOM-PROBE AB The influence of a negative electric field on the near-surface composition of Y-Ba-Cu-O superconductors, which have initially lost oxygen due to exposure to vacuum and FIM imaging, is investigated using a wide-angle atom probe. Field electron emission of about 10(-8) A for about 10 min, at 85 K, causes significant changes in composition which are interpreted to mean primarily that oxygen has diffused to the surface and desorbed, resulting in a more metallic surface. These changes are correlated with recently observed shifts in field ion- and field-electron energy spectra. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. MAX PLANCK GESELL,FRITZ HABER INST,W-1000 BERLIN 33,GERMANY. RP MELMED, AJ (reprint author), CUSTOM PROBES UNLTD,POB 3938,GAITHERSBURG,MD 20878, USA. NR 9 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD APR PY 1991 VL 246 IS 1-3 BP 173 EP 176 DI 10.1016/0039-6028(91)90410-T PG 4 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA FM118 UT WOS:A1991FM11800028 ER PT J AU CAMUS, PP MELMED, AJ AF CAMUS, PP MELMED, AJ TI PERFORMANCE OF A REFLECTRON ENERGY COMPENSATING MIRROR SO SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 37TH INTERNATIONAL SYMP ON FIELD EMISSION CY JUL 29-AUG 03, 1990 CL ALBUQUERQUE, NM SP INT FIELD EMISS SOC ID FLIGHT MASS-SPECTROMETER AB This paper describes the performance characteristics of a first order reflection energy compensating mirror system on a voltage-pulsed atom probe. The performance of the instrument using the electrostatic mirror is compared to that obtained using the same electronics and a linear flight path, and the effect of an einzel lens on the performance is presented. C1 NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899. CUSTOM PROBES UNLTD,GAITHERSBURG,MD 20878. RP CAMUS, PP (reprint author), NATL INST STAND & TECHNOL,DIV SURFACE SCI,GAITHERSBURG,MD 20899, USA. NR 10 TC 4 Z9 4 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 APR PY 1991 VL 246 IS 1-3 BP 415 EP 419 DI 10.1016/0039-6028(91)90445-X PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA FM118 UT WOS:A1991FM11800063 ER PT J AU ELLIOTT, WP ANGELL, JK THONING, KW AF ELLIOTT, WP ANGELL, JK THONING, KW TI RELATION OF ATMOSPHERIC CO2 TO TROPICAL SEA AND AIR TEMPERATURES AND PRECIPITATION SO TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY LA English DT Article; Proceedings Paper CT 3RD INTERNATIONAL CONF ON ANALYSIS AND EVALUATION OF ATMOSPHERIC CO2 DATA, PRESENT AND PAST CY OCT 16-20, 1989 CL HINTERZARTEN, FED REP GER SP WORLD METEOROL ORG, US DOE, DIV CO2 RES, MINIST RES & TECHNOL FED REP GER, MINIST SCI & ARTS FED REP GER, FED ENVIRONM AGCY FED REP GER, HEIDELBERGER KRAFTANLAGEN, INT GEOSPHERE BIOSPHERE PROGRAM AB Associations between the season-to-season changes in CO2 concentration and the sea-surface temperature in the eastern equatorial Pacific, the tropospheric air temperature, and the precipitation in the tropics are explored. The CO2 records at Mauna Loa and the South Pole from the Scripps Institution of Oceanography and the GMCC/NOAA program, as well as the GMCC records at Barrow, Alaska and American Samoa were used after the annual cycle and the growth due to fossil fuel emission has been removed. We find that the correlation between CO2 changes and each of the other variables changes with time. In particular, the period from about 1968 to about 1978 was the period of highest correlation, which was also the period when the climate variables were best correlated with each other. The air temperature and the precipitation were as well correlated with CO2 changes as was SST. Also, there are individual seasons when the CO2 changes are much better correlated with the climate variables than at other seasons. Furthermore, El Nino events, while the source of the largest signal in the CO2 record, are by no means the same from one event to the next. We take these results as further confirmation that the apparent effect of SST on the CO2 record comes less from changes in the equatorial eastern Pacific Ocean than from climate changes throughout the globe. Climate effects on the terrestrial biosphere seem a likely source of much of the interannual variation in atmospheric CO2. RP ELLIOTT, WP (reprint author), NOAA,AIR RESOURCES LAB,SILVER SPRING,MD 20910, USA. NR 0 TC 20 Z9 20 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6509 J9 TELLUS B JI Tellus Ser. B-Chem. Phys. Meteorol. PD APR PY 1991 VL 43 IS 2 BP 144 EP 155 DI 10.1034/j.1600-0889.1991.00009.x PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FG714 UT WOS:A1991FG71400009 ER PT J AU SCHWARZ, FP AF SCHWARZ, FP TI BIOLOGICAL THERMODYNAMIC DATA FOR THE CALIBRATION OF DIFFERENTIAL SCANNING CALORIMETERS - DYNAMIC TEMPERATURE DATA ON THE GEL TO LIQUID-CRYSTAL PHASE-TRANSITION OF DIALKYLPHOSPHATIDYLCHOLINE IN WATER SUSPENSIONS SO THERMOCHIMICA ACTA LA English DT Article ID HEAT-CAPACITY DATA; UNFOLDING TRANSITION; BILAYERS; MEMBRANES; MIXTURES; LIPIDS AB Heat capacity measurements of the gel to liquid crystalline transition of phosphocholine lipid suspensions in buffer solutions were performed using a differential scanning calorimeter (DSC) over a range of experimental conditions. Since the temperatures at the transition peak maxima, i.e. transition temperatures, were observed to increase linearly with scan rate due to the response time of the DSC, they were corrected to zero scan rate and found to agree closely with the literature values. The transition temperatures and enthalpies of the seven dialkylphosphatidylcholine lipids investigated ranged from 286.6 +/- 0.1 K and 15.9 +/- 0.6 kJ mol-1 for 1,2-ditridecanoyl-sn-glycero-3-phosphocholine to 353.7 +/- 0.1 K and 69.1 +/- 3.3 kJ mol-1 for 1,2-ditetracosanoyl-sn-glycero-3-phosphocholine. At the slowest scan rates of 3-5 K h-1, the transition widths at half the peak maximum were close to 0.2 K. The transition temperatures were found to be independent of the following: the ionic strength of the sodium phosphate buffer from 0.01-0.02 M, the pH of the buffer from 6 to 8, the concentration of the suspension from 0.1-1.0 mass%, the commercial source of the lipid, and storage of the lipid in a freezer for 4 years. Suspensions of the dialkylphosphatidylcholine lipids in sodium phosphate buffer solutions can be used as sources of dynamic temperature data for the calibration of DSCs. RP SCHWARZ, FP (reprint author), NATL INST STAND & TECHNOL,CTR ADV RES BIOTECHNOL,9600 GUDELSKY DR,ROCKVILLE,MD 20850, USA. NR 23 TC 8 Z9 8 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-6031 J9 THERMOCHIM ACTA JI Thermochim. Acta PD APR 1 PY 1991 VL 177 BP 285 EP 303 DI 10.1016/0040-6031(91)80105-R PG 19 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA FH151 UT WOS:A1991FH15100027 ER PT J AU GANGOPADHYAY, A JAHANMIR, S AF GANGOPADHYAY, A JAHANMIR, S TI FRICTION AND WEAR CHARACTERISTICS OF SILICON NITRIDE-GRAPHITE AND ALUMINA-GRAPHITE COMPOSITES SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT 45TH ANNUAL MEETING OF THE SOC TRIBOLOGISTS AND LUBRICATION ENGINEERS CY MAY 07-10, 1990 CL DENVER, CO SP SOC TRIBOLOGISTS & LUBRICAT ENGINEERS ID ZIRCONIA; CARBIDE; WATER AB To take advantage of the beneficial properties of advanced ceramics, it is necessary that their friction coefficient be reduced to an acceptable value. One method for achieving this goal is incorporation of a solid lubricant phase in the ceramic matrix. In this study, ceramic-matrix composites were fabricated by drilling a series of small holes in alumina and silicon nitride, which were subsequently filled with NiCl2 intercalated graphite under high pressure. It was found that the addition of graphite to silicon nitride considerably reduces the friction coefficient, but alumina-graphite composites exhibit only a marginal reduction in friction coefficient compared to alumina. The reduction in friction coefficient for silicon nitride-graphite composite can be explained by the formation of transfer films consisting of a mixture of materials from both contacting surfaces. However, for alumina-graphite composites the graphite regions were completely covered with steel wear particles, inhibiting the formation of graphite-containing transfer films. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD. NR 27 TC 31 Z9 32 U1 0 U2 1 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 838 BUSSE HIGHWAY, PARK RIDGE, IL 60068 SN 0569-8197 J9 TRIBOL T JI Tribol. Trans. PD APR PY 1991 VL 34 IS 2 BP 257 EP 265 DI 10.1080/10402009108982034 PG 9 WC Engineering, Mechanical SC Engineering GA FG321 UT WOS:A1991FG32100015 ER PT J AU GILLIES, CW GILLIES, JZ SUENRAM, RD LOVAS, FJ KRAKA, E CREMER, D AF GILLIES, CW GILLIES, JZ SUENRAM, RD LOVAS, FJ KRAKA, E CREMER, D TI VANDERWAALS COMPLEXES IN 1,3-DIPOLAR CYCLOADDITION REACTIONS - OZONE ETHYLENE SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ELECTRON CORRELATION-ENERGY; MICROWAVE-SPECTRUM; MOLECULAR-STRUCTURE; PERTURBATION-THEORY; ORIENTED MOLECULES; DIPOLE-MOMENT; REACTIVITY; BEAM; STATE; ORIENTATION AB Microwave spectra of O3-CH2=CH2, O3-CD2=CH2, O3-trans-CHD=CHD, and O3-cis-CHD=CHD have been observed with a pulsed-beam Fabry-Perot cavity, Fourier transform microwave spectrometer. Internal motions in the van der Waals complex give two states for the normal, 1,1-dideuterated and trans-1,2-dideuterated isotopic forms. The c-type transitions of the two states for the isotopic species above, as well as the one observed isotopic form of O3-cis-CHD=CHD, independently fit to an asymmetric top Watson Hamiltonian. Stark effect measurements for O3-CH2=CH2 give mu-a = 0.017 (1) D and mu-c = 0.466 (2) D. The microwave data are only consistent with a structure having C(S) symmetry in which the nearly parallel planes of ethylene and ozone have a center of mass separation of R(cm) = 3.290 (3) angstrom. Ab initio calculations at the MP4 level indicate that the preferred geometry corresponds to small tilts of the ozone and ethylene planes, which place an exo-oriented pair of hydrogens toward the terminal oxygens of ozone. Both the theoretical and microwave results suggest the tunneling splitting arises at least in part from a 180-degrees rotation of ethylene about its C2 axis, which is perpendicular to the ethylene plane. 1,3-Dipolar cycloaddition theory, orbital symmetry rules, and ab initio calculations of the complex and transition states are used to argue that O3-CH2=CH2 lies in a shallow minimum on the reaction coordinate prior to the transition state in the reaction of ozone plus ethylene, which produces the primary product 1,2,3-trioxolane. C1 UNION UNIV UNION COLL,DEPT CHEM,SCHENECTADY,NY 12308. NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. GOTHENBURG UNIV,S-41296 GOTHENBURG,SWEDEN. RP GILLIES, CW (reprint author), RENSSELAER POLYTECH INST,DEPT CHEM,TROY,NY 12180, USA. NR 58 TC 97 Z9 99 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAR 27 PY 1991 VL 113 IS 7 BP 2412 EP 2421 DI 10.1021/ja00007a010 PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA FD837 UT WOS:A1991FD83700010 ER PT J AU BENDERSKY, LA BIANCANIELLO, FS RIDDER, SD SHAPIRO, AJ AF BENDERSKY, LA BIANCANIELLO, FS RIDDER, SD SHAPIRO, AJ TI MICROSTRUCTURAL CHARACTERIZATION OF ATOMIZED POWDER OF AL-5MN-5FE-2SI (WT-PERCENT) ALLOY SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 7TH INTERNATIONAL CONF ON RAPIDLY QUENCHED MATERIALS CY AUG 13-17, 1990 CL STOCKHOLM, SWEDEN SP ALLIED SIGNAL, VACUUMSCHMELZE, SANDVIK, MATERIAL CENTER, SWEDISH NATL BOARD TECH DEV, ROYAL INT TECHNOL, CITY STOCKHOLM, STOCKHOLM COUNTY COUNCIL ID FE AB Aluminum-based Al-TM-Si (TM = transition metal) when rapidly solidified (RS) and consolidated could show a microstructure of fine, slow coarsening dispersoids. One such alloy, Al-5Mn-5Fe-2Si (wt.%), in its RS condition was studied in this work by scanning and transmission electron microscopy. The alloy powder was prepared by an inert gas atomization technique. The powder was separated to different particle size fractions in order to determine its microstructural dependence on particle size. The following microstructures (with increasing particle size) were observed: microcellular/cellular aluminum with an amorphous-type intercellular phase, eutectic and primary globular particles. The observed structures of the globular particles display various growth forms of the alpha(AlMnFeSi) intermetallic phase depending on the degree of undercooling. The icosahedral symmetry of naturally occurring polycrystalline aggregates or defective quasicrystals is related to the icosahedral symmetry of the alpha(AlMnFeSi) phase structural motif. RP BENDERSKY, LA (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 9 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD MAR 25 PY 1991 VL 134 BP 1098 EP 1102 DI 10.1016/0921-5093(91)90932-D PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA FH740 UT WOS:A1991FH74000056 ER PT J AU SZAFLARSKI, DM MULLIN, AS YOKOYAMA, K ASHFOLD, MNR LINEBERGER, WC AF SZAFLARSKI, DM MULLIN, AS YOKOYAMA, K ASHFOLD, MNR LINEBERGER, WC TI CHARACTERIZATION OF TRIPLET-STATES IN DOUBLY CHARGED POSITIVE-IONS - ASSIGNMENT OF THE 3-PI-G-3-SIGMA-U+ ELECTRONIC-TRANSITION IN N22+ SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Letter ID TRANSLATIONAL-ENERGY SPECTROSCOPY; MOLECULAR NITROGEN; NO2+; IONIZATION; DICATIONS; CLUSTERS; SPECTRUM; EMISSION; N-2(2+); IMPACT AB The first direct spectroscopic evidence and characterization of triplet states in a molecular dication is reported. The 3-PI-g <-- 3-SIGMA-u+ electronic absorption between excited states of N2(2+) is recorded by ion-laser coaxial beam photofragmentation spectroscopy. Over 300 rotational lines are resolved, and 13 parameters characterizing the upper and lower electronic states are determined. The results are compared with calculated potential energy curves. Dissociation lifetimes of the upper rotational levels are measured, and possible mechanisms of dissociation are discussed. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RI Mullin, Amy/C-4099-2009 NR 41 TC 35 Z9 35 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 21 PY 1991 VL 95 IS 6 BP 2122 EP 2124 DI 10.1021/j100159a009 PG 3 WC Chemistry, Physical SC Chemistry GA FD112 UT WOS:A1991FD11200009 ER PT J AU SENEKOWITSCH, J ONEIL, S KNOWLES, P WERNER, HJ AF SENEKOWITSCH, J ONEIL, S KNOWLES, P WERNER, HJ TI THE 3-PI-G[-3-SIGMA-U+ TRANSITION IN N22+ SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Letter ID N-2(2+); STATE AB As part of a theoretical reexamination of the electronic states of N2(2+), we have used multireference configuration interaction wave functions with CASSCF reference states and a [5s,4p,3d,2f,1g] generally contracted Gaussian basis to calculate ab initio potential curves of the excited 3-SIGMA-u+ and 3-PI-g electronic states. The calculated energy difference and spectroscopic constants support the assignment of the N2(2+) spectral lines observed near 15 300 cm-1 as the upsilon' = 0 <-- upsilon" = 0 band of the 3-PI-g <-- 3-SIGMA-u+ transition. The upsilon' = 0 <-- upsilon" = 1 band is predicted to lie at 13 146 cm-1 and the upsilon' = 1 <-- upsilon" = 0 band at 16 246 cm-1. The latter transition may be the broad, unassigned feature observed by Cosby and co-workers near that energy. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV SUSSEX,SCH CHEM & MOLEC SCI,BRIGHTON BN1 9QJ,E SUSSEX,ENGLAND. UNIV BIELEFELD,FACHBEREICH CHEM,W-4800 BIELEFELD,GERMANY. RI Knowles, Peter/G-2985-2010; Werner, Hans-Joachim/G-9509-2011 OI Knowles, Peter/0000-0003-4657-6331; Werner, Hans-Joachim/0000-0002-0435-539X NR 19 TC 50 Z9 50 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 21 PY 1991 VL 95 IS 6 BP 2125 EP 2127 DI 10.1021/j100159a010 PG 3 WC Chemistry, Physical SC Chemistry GA FD112 UT WOS:A1991FD11200010 ER PT J AU ANNE, A HAPIOT, P MOIROUX, J NETA, P SAVEANT, JM AF ANNE, A HAPIOT, P MOIROUX, J NETA, P SAVEANT, JM TI OXIDATION OF 10-METHYLACRIDAN, A SYNTHETIC ANALOG OF NADH, AND DEPROTONATION OF ITS CATION RADICAL - CONVERGENT APPLICATION OF LASER FLASH-PHOTOLYSIS AND DIRECT AND REDOX CATALYZED ELECTROCHEMISTRY TO THE KINETICS OF DEPROTONATION OF THE CATION RADICAL SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ELECTRON-TRANSFER REACTIONS; LINEAR SWEEP VOLTAMMETRY; AQUEOUS-SOLUTIONS; HYDRIDE-TRANSFER; RATE CONSTANTS; METHYLPEROXYL RADICALS; PEROXYL RADICALS; REDUCTION; MECHANISM; REACTIVITY AB Photolysis of 10-methylacridan (AH) in acetonitrile solutions containing CCl4 led to quantitative oxidation of AH to A+. Laser flash photolysis of the solution with 248- or 308-nm light yielded the cation radical AH.+ which decays by deprotonation to give the neutral radical A.. AH.+ could be also generated by means of homogeneous redox catalysis using variously substituted ferrocenes and the rate of deprotonation k(H) by various bases was derived from both techniques. There is a good agreement between the values determined for k(H) (here and, previously, by direct electrochemistry using ultramicroelectrodes). The vast majority of the data points in a plot of log k(H) vs the pK(a) of the bases, covering 18 pK(a) units and rate constants up to the diffusion limit, fall on the same Bronsted line in spite of the fact that they involve bases of quite different structure: pyridines, aliphatic nitrogen bases, and carboxylates. Gamma-radiolysis of acetonitrile/CCl4/AH solutions also resulted in quantitative oxidation to A+. However, pulse radiolysis of this system indicated relatively slow oxidation of AH by Cl3COO. radicals. Pulse radiolysis experiments in acidic aqueous solutions showed that AH is oxidized by Cl2.- to give AH.+, which decays with a first-order rate constant of 9 x 10(2) s-1. Reduction of A+ gave A. which did not undergo protonation even at 2 M HClO4, but reaction of A+ with H atoms resulted in partial addition of H to the 9-position to give AH.+. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. UNIV PARIS 07,ELECTROCHIM MOLEC LAB,URA 438,F-75251 PARIS 05,FRANCE. NR 58 TC 50 Z9 50 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 21 PY 1991 VL 95 IS 6 BP 2370 EP 2377 DI 10.1021/j100159a047 PG 8 WC Chemistry, Physical SC Chemistry GA FD112 UT WOS:A1991FD11200047 ER PT J AU HARRIMAN, A SHOUTE, LCT NETA, P AF HARRIMAN, A SHOUTE, LCT NETA, P TI RADIATION-CHEMISTRY OF CYANINE DYES - OXIDATION AND REDUCTION OF MEROCYANINE-540 SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID AQUEOUS-SOLUTION; RESONANCE RAMAN; RATE CONSTANTS; VISIBLE-LIGHT; RADICALS; STATE; PHOTOISOMERIZATION; DIPHENYLBUTADIENE; PORPHYRINS; KINETICS AB Merocyanine 540 (MC) shows promise as a treatment for certain types of leukemia. It is shown that MC readily undergoes one-electron reduction under pulse radiolytic conditions. The pi-radical anion, produced by reduction with hydrated electrons and 2-hydroxypropyl radicals, disproportionates rapidly (k = 1.9 x 10(9) M-1 s-1) under anaerobic conditions but reduces O2 to superoxide ions (k = 1.6 x 10(9) M-1 s-1) in aerated solution. The dye reacts with trichloromethylperoxyl radicals (k = 9 x 10(8) M-1 s-1) to form several products, one of which is believed to be an adduct formed by addition of CCl3OO. to the bridgehead carbon atom of the benzoxazole subunit. This species decays via first-order kinetics (k = 4.0 x 10(3) s-1) under pulse radiolytic conditions to form cleavage products. A second primary product is believed to arise from addition of CCl3O2. to the polymethine chain to form an alpha-amino carbon-centered radical capable of reducing O2 to superoxide ions. Preliminary studies indicate that the breakdown products are cytotoxic and could be important intermediates for the known antiviral activity of MC. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. RP HARRIMAN, A (reprint author), UNIV TEXAS,CTR FAST KINET RES,AUSTIN,TX 78712, USA. NR 47 TC 23 Z9 23 U1 2 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD MAR 21 PY 1991 VL 95 IS 6 BP 2415 EP 2420 DI 10.1021/j100159a055 PG 6 WC Chemistry, Physical SC Chemistry GA FD112 UT WOS:A1991FD11200055 ER PT J AU TURNIPSEED, SB BARKLEY, RM SIEVERS, RE AF TURNIPSEED, SB BARKLEY, RM SIEVERS, RE TI SYNTHESIS AND CHARACTERIZATION OF ALKALINE-EARTH-METAL BETA-DIKETONATE COMPLEXES USED AS PRECURSORS FOR CHEMICAL VAPOR-DEPOSITION OF THIN-FILM SUPERCONDUCTORS SO INORGANIC CHEMISTRY LA English DT Article ID ION MASS-SPECTROMETRY; SPECTRA AB Several of the beta-diketonate metal complexes used for metal organic chemical vapor deposition (MOCVD) of thin-film superconductors have been characterized by thermogravimetric analysis, mass spectrometry, and gas chromatography/mass spectrometry. The volatility of the alkaline-earth-metal chelates has been studied, and it has been determined that one reason the alkaline-earth-metal chelates are less volatile than other metal beta-diketonates is that they exist as oligomers. For example, one barium beta-diketonate chelate consists of a cluster of five metal ions bridged by beta-diketonate carbonyl oxygens and water molecules. It has also been found that the addition of uncomplexed (protonated) beta-keto enolate ligand to the carrier gas stream greatly improves the gas chromatographic behavior of these alkaline-earth-metal chelates, probably owing to adduct formation accompanying the dissociation of the oligomers. The results of these studies, as well as the implications for using these chelates together with auxiliary ligands for MOCVD, will be discussed. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,CAMPUS BOX 216,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 25 TC 139 Z9 140 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD MAR 20 PY 1991 VL 30 IS 6 BP 1164 EP 1170 DI 10.1021/ic00006a003 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA FD041 UT WOS:A1991FD04100003 ER PT J AU GIERCZAK, T TALUKDAR, R VAGHJIANI, GL LOVEJOY, ER RAVISHANKARA, R AF GIERCZAK, T TALUKDAR, R VAGHJIANI, GL LOVEJOY, ER RAVISHANKARA, R TI ATMOSPHERIC FATE OF HYDROFLUOROETHANES AND HYDROFLUOROCHLOROETHANES .1. RATE COEFFICIENTS FOR REACTIONS WITH OH SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TEMPERATURE-DEPENDENCE; RADICAL REACTIONS; CLIMATE CHANGE; KINETICS; CH3CHF2; 297-K AB The rate coefficients for the reactions of OH with five halocarbons [CF3CH2F (HFC 134a), CF3CHClF (HCFC 124), CF3CHCl2 (HCFC 123), CH3CHF2 (HFC 152a), and CH3CF2Cl (HCFC 142b)], which are proposed as alternatives to chlorofluoromethanes, have been measured. A pulsed photolysis system and a discharge flow apparatus were used to measure the rate coefficients between approximately 210 and 425 K. Use of the complementary technique enabled identification of systematic errors and minimization of these errors. The obtained values are compared with values previously measured by other groups. This data base is used in the subsequent paper to calculate the atmospheric lifetimes of the five compounds. C1 NOAA, AERON LAB, R-E-AL2, 325 BROADWAY, BOULDER, CO 80303 USA. UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RI TALUKDAR, RANAJIT/G-4530-2013; Ravishankara, Akkihebbal/A-2914-2011 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; NR 28 TC 61 Z9 61 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1991 VL 96 IS D3 BP 5001 EP 5011 DI 10.1029/90JD02736 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FD794 UT WOS:A1991FD79400003 ER PT J AU ORLANDO, JJ BURKHOLDER, JB MCKEEN, SA RAVISHANKARA, AR AF ORLANDO, JJ BURKHOLDER, JB MCKEEN, SA RAVISHANKARA, AR TI ATMOSPHERIC FATE OF SEVERAL HYDROFLUOROETHANES AND HYDROCHLOROETHANES .2. UV ABSORPTION CROSS-SECTIONS AND ATMOSPHERIC LIFETIMES SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERE; OZONE AB The temperature dependent UV absorption cross-sections of the hydrochlorofluoroethanes CF3CHFCl, CH3CF2Cl, and CF3CHCl2 are reported. The UV absorption cross-sections were measured over the temperature range 203 to 295 K and the wavelength range 190 to 230 nm. The hydrofluorocarbons CH3CF2H and CF3CH2F were also studied at 295 K and upper limits for their UV absorption cross-sections over the wavelength range 190 to 230 nm were obtained. The atmospheric lifetimes of these species were calculated using a one-dimensional atmospheric model, using the kinetic data obtained in the previous paper (Gierczak et al. 1991) and the absorption cross-section data obtained in the present study. C1 NOAA, AERON LAB, R-E-AL2, 325 BROADWAY, BOULDER, CO 80303 USA. UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RI Burkholder, James/H-4914-2013; McKeen, Stuart/H-9516-2013; Ravishankara, Akkihebbal/A-2914-2011 NR 19 TC 34 Z9 34 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1991 VL 96 IS D3 BP 5013 EP 5023 DI 10.1029/90JD02734 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FD794 UT WOS:A1991FD79400004 ER PT J AU BURKHOLDER, JB WILSON, RR GIERCZAK, T TALUKDAR, R MCKEEN, SA ORLANDO, JJ VAGHJIANI, GL RAVISHANKARA, AR AF BURKHOLDER, JB WILSON, RR GIERCZAK, T TALUKDAR, R MCKEEN, SA ORLANDO, JJ VAGHJIANI, GL RAVISHANKARA, AR TI ATMOSPHERIC FATE OF CF3BR, CF2BR2, CF2CLBR, AND CF2BRCF2BR SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OZONE; OH; STRATOSPHERE; KINETICS; VAPOR; PHASE AB The temperature dependent UV absorption cross sections of the haloalkanes CF3Br, CF2ClBr, CF2Br2, and CF2BrCF2Br are reported. The UV absorption cross sections were measured over the temperature range 210 to 296 K and the wavelength range 190 to 320 nm. Upper limit of the rate coefficients for the reactions of OH with CF3Br, CF2Br2, CF2ClBr, and CF2BrCF2Br were also determined using both pulsed photolysis and flow tube techniques. The rate coefficients at 296 K were found to be < 1.2 x 10(-16), < 1.5 x 10(-16), < 5.0 x 10(-16), and < 1.5 x 10(-16) cm3 molec-1 s-1 for CF3Br, CF2ClBr, CF2Br2, and CF2BrCF2Br, respectively. The UV absorption cross-section data and OH reaction rate coefficients of these species were combined with a one-dimensional model to yield atmospheric lifetimes of 65, 16, 3.2, and < 20 years for CF3Br, CF2ClBr, CF2Br2, and CF2BrCF2Br, respectively. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RP BURKHOLDER, JB (reprint author), NOAA, AERON LAB, R-E-AL2, 325 BROADWAY, BOULDER, CO 80303 USA. RI TALUKDAR, RANAJIT/G-4530-2013; Burkholder, James/H-4914-2013; McKeen, Stuart/H-9516-2013; Ravishankara, Akkihebbal/A-2914-2011 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; NR 19 TC 42 Z9 42 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1991 VL 96 IS D3 BP 5025 EP 5043 DI 10.1029/90JD02735 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FD794 UT WOS:A1991FD79400005 ER PT J AU MURPHY, DM AF MURPHY, DM TI OZONE LOSS RATES CALCULATED ALONG ER-2 FLIGHT TRACKS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOUTH POLAR VORTEX; ANTARCTIC OZONE; 72-DEGREES-S LATITUDE; INSITU OBSERVATIONS; CLO; BRO; 54-DEGREES-S; STRATOSPHERE AB Local ozone loss rates due to the ClO + ClO and BrO + ClO cycles are calculated using ClO, pressure, and temperature from in-situ aircraft measurements and representative BrO mixing ratios. Ozone loss during the vertical profiles executed by the ER-2 near 72-degrees-S usually extended over a deep altitude range rather than reaching a maximum at the top of the profiles. This is due to the strong pressure dependence of the rate determining steps. In the Antarctic, very high ozone loss rates (> 5.10(6) cm-3 s-1) were observed at altitudes with potential temperatures below 400 K, where advective exchange is likely to be much more rapid than at higher altitudes. On September 22, 1987, the ER-2 measured an ozone loss rate of about 2.8 Dobson units (DU) per 12 sunlit hours in the 350-400 K range and 2.0 DU in the 400-450 K range near 72-degrees-S. Rapid ozone loss in the Arctic did not extend below 400 K in the available data. The calculated average loss rate, which is nonlinear, in general depends on the order in which the terms are averaged. Loss rates calculated by averaging the ClO, pressure and temperature for up to 2400 s (about 500 km) generally agree with the average of the local loss rate to within one percent except at the edge of the vortex, where the difference can be up to 30%. Adiabatic temperature changes of up to 10 K change the ozone loss rate by less than 10% because the temperature and pressure effects nearly cancel. Thermal decomposition of Cl2O2 was not important along sunlit portions of ER-2 flight tracks if equilibrium is assumed between ClO and Cl2O2. The effect of recalibration of the ClO data on the calculated loss rates is discussed. RP MURPHY, DM (reprint author), NOAA, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. RI Murphy, Daniel/J-4357-2012 OI Murphy, Daniel/0000-0002-8091-7235 NR 33 TC 16 Z9 16 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1991 VL 96 IS D3 BP 5045 EP 5053 DI 10.1029/90JD02712 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FD794 UT WOS:A1991FD79400006 ER PT J AU HANSON, DR RAVISHANKARA, AR AF HANSON, DR RAVISHANKARA, AR TI THE REACTION PROBABILITIES OF CLONO2 AND N2O5 ON POLAR STRATOSPHERIC CLOUD MATERIALS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ANTARCTIC OZONE DEPLETION; HETEROGENEOUS REACTIONS; HYDROGEN-CHLORIDE; RATE CONSTANTS; ICE SURFACES; NITRIC-ACID; HCL; CHEMISTRY; KINETICS; H2O AB The reaction probabilities, gamma, of ClONO2 and N2O5 on ice and nitric acid trihydrate (NAT) surfaces were determined, using reactant concentrations that are typical of the lower stratosphere, by measuring the first-order reactant loss rate coefficients over the substrate located on the walls of a fast-flow reactor. Reactants were detected using chemical ionization mass spectrometry, a sensitive technique which allows the use of low reactant concentrations. The reaction probabilities obtained for ClONO2 are: 0.3 (-0.1 +0.7) on pure ice, 0.006 (+/- 30%) over a NAT surface, and 0.3 (-0.1 +0.7) on an HCl-doped NAT surface. Those for N2O5 are: 0.024 (+/- 30%) on pure ice, 0.0006 (+/- 50%) on a NAT surface, and 0.0032 (+/- 30%) on an HCl-doped NAT surface. We observed that an ice surface will be converted into a less reactive HNO3-doped ice surface in a relatively short time, and we present arguments that this surface consisted of a NAT layer. The large differences between our results and previous measurements for some of these gamma can be attributed to the relatively large reactant concentrations used in the previous work. The major implications of this work for polar stratospheric chlorine activation are: an efficient loss of ClONO2 on pure ice surfaces, a very rapid rate for the reaction ClONO2 + HCl on NAT surfaces, and that pure ice surfaces will become "passivated" when coated with one monolayer of NAT crystal. RP NOAA, AERON LAB, 325 BROADWAY, R-E-AL2, BOULDER, CO 80303 USA. RI Ravishankara, Akkihebbal/A-2914-2011 NR 51 TC 186 Z9 188 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1991 VL 96 IS D3 BP 5081 EP 5090 DI 10.1029/90JD02613 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FD794 UT WOS:A1991FD79400009 ER PT J AU BOWDLE, DA ROTHERMEL, J VAUGHAN, JM BROWN, DW POST, MJ AF BOWDLE, DA ROTHERMEL, J VAUGHAN, JM BROWN, DW POST, MJ TI AEROSOL BACKSCATTER MEASUREMENTS AT 10.6 MICROMETERS WITH AIRBORNE AND GROUND-BASED CO2 DOPPLER LIDARS OVER THE COLORADO HIGH-PLAINS .1. LIDAR INTERCOMPARISON SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CO2-LASER HETERODYNE SYSTEMS; THEORETICAL SNRS; POLARIZATION; CALIBRATION AB An airborne continuous wave (CW) focused CO2 Doppler lidar and a ground-based pulsed CO2 Doppler lidar were used to obtain seven pairs of comparative measurements of tropospheric aerosol backscatter profiles at 10.6-mu-m wavelength, near Denver, Colorado, during a 20-day period in July 1982. In regions of uniform backscatter the two lidars show good agreement, with differences usually less than approximately 50% near 8-km altitude and less than a factor of 2 or 3 elsewhere but with the pulsed lidar often lower than the CW lidar. Near sharp backscatter gradients the two lidars show poorer agreement, with the pulsed lidar usually higher than the CW lidar. Most discrepancies arise from a combination of atmospheric factors and instrument factors, particularly small-scale areal and temporal backscatter heterogeneity above the planetary boundary layer, unusual large-scale vertical backscatter structure in the upper troposphere and lower stratosphere, and differences in the spatial resolution, detection threshold, and noise estimation for the two lidars. C1 NOAA, WAVE PROPAGAT LAB, BOULDER, CO 80303 USA. NASA, GEORGE C MARSHALL SPACE FLIGHT CTR, SPACE SCI LAB, HUNTSVILLE, AL 35812 USA. ROYAL SIGNALS & RADAR ESTAB, MALVERN WR14 3PS, WORCS, ENGLAND. RP BOWDLE, DA (reprint author), UNIV ALABAMA, JOHNSON RES CTR, RE-212, HUNTSVILLE, AL 35899 USA. NR 27 TC 12 Z9 12 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1991 VL 96 IS D3 BP 5327 EP 5335 DI 10.1029/90JD02156 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FD794 UT WOS:A1991FD79400031 ER PT J AU BOWDLE, DA ROTHERMEL, J VAUGHAN, JM POST, MJ AF BOWDLE, DA ROTHERMEL, J VAUGHAN, JM POST, MJ TI AEROSOL BACKSCATTER MEASUREMENTS AT 10.6 MICROMETERS WITH AIRBORNE AND GROUND-BASED CO2 DOPPLER LIDARS OVER THE COLORADO HIGH-PLAINS .2. BACKSCATTER STRUCTURE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SIZE DISTRIBUTIONS; 10.6-MU-M; PARTICLES; PROFILES AB Measurements of tropospheric aerosol volume backscatter coefficients at 10.6-mu-m wavelength were obtained with airborne continuous wave and ground-based pulsed CO2 Doppler lidars over the Colorado High Plains during a 20-day period in summer 1982. A persistent "background" layer was found between 6- and 10-km altitude, with a generally uniform backscatter mixing ratio of approximately 10(-10) m2 kg-1 sr-1. The upper boundary of this background layer varied with the tropopause height; the lower boundary varied with the strength and diurnal cycle of convective mixing in the planetary boundary layer (PBL). For quiescent meteorological conditions the transition from the PBL to the background layer was usually very sharp, with backscatter decreases sometimes as large as 3 decades in approximately 70 m. Sharp gradients were also found at the boundaries of shallow (tens of meters) subvisible cirrus clouds. For less stable conditions, associated with vertical aerosol transport by deep cumuliform clouds, backscatter tended to decrease exponentially with altitude. C1 NOAA, WAVE PROPAGAT LAB, BOULDER, CO 80303 USA. NASA, GEORGE C MARSHALL SPACE FLIGHT CTR, SPACE SCI LAB, HUNTSVILLE, AL 35812 USA. ROYAL SIGNALS & RADAR ESTAB, MALVERN WR14 3PS, WORCS, ENGLAND. RP BOWDLE, DA (reprint author), UNIV ALABAMA, JOHNSON RES CTR, RE-212, HUNTSVILLE, AL 35899 USA. NR 18 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 20 PY 1991 VL 96 IS D3 BP 5337 EP 5344 DI 10.1029/90JD02157 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FD794 UT WOS:A1991FD79400032 ER PT J AU BENTZ, DP MARTIN, JW BATTS, ME AF BENTZ, DP MARTIN, JW BATTS, ME TI CHARACTERIZATION OF CYLINDRICAL HOLES IN METALLIC SUBSTRATES VIA THEIR INFRARED-EMISSION PATTERNS SO WEAR LA English DT Article AB IR emission patterns for a series of cylindrical holes milled into aluminum and steel plates were compared with those predicted from existing theory. The emission patterns were found to be influenced by the hole geometry, the substrate material and the IR camera system itself. For holes milled into an aluminum plate, the results were adequately explained by existing theory for diffuse materials. For holes milled into a steel plate, however, this theory was found not to apply and empirical calibration was required. It is concluded that the IR technique may have promise in characterizing the diameter and depth of milled holes at temperatures near ambient. C1 PARATECH CORP,WASHINGTON,DC 20008. RP BENTZ, DP (reprint author), NATL INST STAND & TECHNOL,CTR BLDG TECHNOL,GAITHERSBURG,MD 20899, USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD MAR 20 PY 1991 VL 143 IS 2 BP 255 EP 266 DI 10.1016/0043-1648(91)90100-9 PG 12 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA FE692 UT WOS:A1991FE69200005 ER PT J AU REDDY, P MCKENNEY, K AF REDDY, P MCKENNEY, K TI MAPPING DOMAINS IN PROTEINS - DISSECTION OF THE REGULATORY AND CATALYTIC DOMAINS IN ESCHERICHIA-COLI ADENYLATE-CYCLASE SO FASEB JOURNAL LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. NR 2 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 19 PY 1991 VL 5 IS 6 BP A1550 EP A1550 PN 3 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA FE557 UT WOS:A1991FE55700539 ER PT J AU ONO, RH GOODRICH, LF BEALL, JA JOHANSSON, ME REINTSEMA, CD AF ONO, RH GOODRICH, LF BEALL, JA JOHANSSON, ME REINTSEMA, CD TI MAGNETIC-FIELD DEPENDENCE OF THE CRITICAL CURRENT ANISOTROPY IN NORMAL METAL-YBA2CU3O7-DELTA THIN-FILM BILAYERS SO APPLIED PHYSICS LETTERS LA English DT Article AB We have measured the transport critical current density (J(c)) in epitaxial quality films of YBa2Cu3O7-delta some of which were covered by thin (10 nm) Ag films. The films, both with and without Ag, had J(c) values greater than 10(6) A/cm2 in liquid nitrogen. The effect of the Ag was to greatly reduce the dependence of J(c) on external magnetic fields in the case where the field was oriented in the plane of the film, that is, perpendicular to the c axis. It is unlikely that the effect is simply due to altered surface pinning, although qualitative agreement with critical state models is observed. RP ONO, RH (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 13 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 18 PY 1991 VL 58 IS 11 BP 1205 EP 1207 DI 10.1063/1.104365 PG 3 WC Physics, Applied SC Physics GA FD848 UT WOS:A1991FD84800030 ER PT J AU CRAFT, N LI, Y COXON, B AF CRAFT, N LI, Y COXON, B TI IDENTIFICATION AND QUANTITATIVE-DETERMINATION OF BETA-CAROTENE ISOMERS IN SRM-968 AND NORMAL HUMAN SERUM USING MULTIDIMENSIONAL CHROMATOGRAPHY SO FASEB JOURNAL LA English DT Meeting Abstract C1 NATL INST STANDARDS & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 15 PY 1991 VL 5 IS 5 BP A1074 EP A1074 PN 2 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA FC550 UT WOS:A1991FC55000909 ER PT J AU MARGOLIS, SA AF MARGOLIS, SA TI ASSESSMENT OF THE HPLC METHOD OF ANALYSIS OF FMOC DERIVATIVES OF AMINO-ACIDS AND THE MEASUREMENT OF TRACE IMPURITIES IN AMINO-ACID SAMPLES SO FASEB JOURNAL LA English DT Meeting Abstract C1 NATL INST STAND TECH,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 15 PY 1991 VL 5 IS 5 BP A1183 EP A1183 PN 2 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA FC550 UT WOS:A1991FC55001538 ER PT J AU ROBINS, LH TJOSSEM, PJH SMYTH, KC BARNES, PY FARABAUGH, EN FELDMAN, A AF ROBINS, LH TJOSSEM, PJH SMYTH, KC BARNES, PY FARABAUGH, EN FELDMAN, A TI PHOTOLUMINESCENCE EXCITATION BY BAND-GAP OPTICAL-ABSORPTION IN CHEMICAL VAPOR-DEPOSITION DIAMOND FILMS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CATHODOLUMINESCENCE; LUMINESCENCE AB Photoluminescence excitation (PLE) spectra at photon energies near the indirect band gap of diamond have been obtained for diamond films grown by the filament-assisted chemical vapor deposition (CVD) method. The PLE intensity was observed to increase abruptly with photon energy above 5.5 eV. This increase coincides with the onset of phonon-emission-assisted interband absorption, which was observed independently by diffuse transmittance measurements. A lower-energy PLE threshold at approximately 5.25 eV, which coincides approximately with the onset of phonon-absorption-assisted interband absorption, was observed in the spectrum of a gem-quality natural diamond, but not in the spectra of the CVD-grown films. Emission spectra of the luminescence excited by above-band-gap photons have features similar to luminescence spectra of the same specimens excited by 20-keV electrons. The spectrally integrated intensities of the luminescence excited by above-band-gap photons and by electrons were found to vary from specimen to specimen in a linearly related manner, suggesting that similar recombination processes occur in both cases. RP ROBINS, LH (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 19 TC 9 Z9 9 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAR 15 PY 1991 VL 69 IS 6 BP 3702 EP 3708 DI 10.1063/1.348463 PG 7 WC Physics, Applied SC Physics GA FD440 UT WOS:A1991FD44000045 ER PT J AU WOODBRIDGE, EL ASHFOLD, MNR LEONE, SR AF WOODBRIDGE, EL ASHFOLD, MNR LEONE, SR TI PHOTODISSOCIATION OF AMMONIA AT 193.3 NM - ROVIBRATIONAL STATE DISTRIBUTION OF THE NH2(A2A1) FRAGMENT SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LASER-INDUCED FLUORESCENCE; ELECTRONIC GROUND-STATE; RESOLVED FTIR EMISSION; ABSORPTION-SPECTRUM; VIBRATIONAL DISTRIBUTIONS; 2-PHOTON FORMATION; ROTATIONAL-STATE; SYMMETRIC TOPS; A1A2'' STATE; NH2 AB The rovibrational state distribution of the nascent NH2(A-approximately 2A1) fragments generated by 193.3 nm photodissociation of a room temperature sample of NH3 is determined through an analysis of a major portion (6000-13 000 cm-1) of the NH2(A-approximately 2A1 --> X-approximately 2B1) near infrared emission spectrum obtained by time-resolved Fourier transform infrared emission spectroscopy. The NH2(A-approximately) fragments are observed to be formed predominantly in their zero-point vibrational level, with substantial rotational excitation about their a-inertial axis up to the limit of the available energy, approximately 3150 cm-1, but with little excitation about the other axes. The pattern of this energy disposal is discussed within the framework of existing knowledge regarding the form of the NH3 A-approximately state potential energy surface on which the dissociation occurs. The essential features are entirely consistent with a direct carry over, into the fragment, of the out-of-plane bending vibrational motion introduced in the parent molecule by the photoexcitation process. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP WOODBRIDGE, EL (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 42 TC 71 Z9 71 U1 0 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 15 PY 1991 VL 94 IS 6 BP 4195 EP 4204 DI 10.1063/1.460653 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FD735 UT WOS:A1991FD73500011 ER PT J AU OVERLAND, JE GUEST, PS AF OVERLAND, JE GUEST, PS TI THE ARCTIC SNOW AND AIR-TEMPERATURE BUDGET OVER SEA ICE DURING WINTER SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID BOUNDARY-LAYER; MODEL AB Arctic cooling through the fall-winter transition is calculated from a coupled atmosphere-sea ice thermal model and compared to temperature soundings and surface measurements made north of Svalbard during the Coordinated Eastern Arctic Experiment (CEAREX). A typical winter, clear-sky vertical temperature structure of the polar air mass is composed of a surface-based temperature inversion or an inversion above a very shallow (30-180 m) mechanically mixed boundary layer with temperatures -30-degrees to -35-degrees-C, a broad temperature maximum layer of -20-degrees to -25-degrees-C between 0.5 and 2 km, and a negative lapse rate aloft. Because the emissivity of the temperature maximum layer is less than that of the snow surface, radiative equilibrium maintains this low level temperature inversion structure. A 90-day simulation shows that heat flux through the ice is insufficient to maintain a local thermal equilibrium. Northward temperature advection by transient storms is required to balance outward longwave radiation to space. Leads and thin ice (< 0.8 m) contribute 12% to the winter tropospheric heat balance in the central Arctic. CEAREX temperature soundings and longwave radiation data taken near 81-degrees-N show polar air mass characteristics by early November, but numerous storms interrupted this air mass during December. Snow temperature changes of 15-degrees-C occurred in response to changes in downward atmospheric longwave radiation of 90 W m-2 between cloud and clear sky. We propose that the strength of boundary layer stability, and thus the degree of air-ice momentum coupling, is driven by the magnitude of the radiation deficit (downward-outward longwave) at the surface and the potential temperature of the temperature maximum layer. This concept is of potential benefit in prescribing atmospheric forcing for sea ice models because a surface air temperature-snow temperature difference field is difficult to obtain and it may be possible to obtain a radiation deficit field via satellite sensors. C1 USN,POSTGRAD SCH,MONTEREY,CA 93943. RP OVERLAND, JE (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAYNE,SEATTLE,WA 98115, USA. NR 21 TC 73 Z9 73 U1 3 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 1991 VL 96 IS C3 BP 4651 EP 4662 DI 10.1029/90JC02264 PG 12 WC Oceanography SC Oceanography GA FC252 UT WOS:A1991FC25200010 ER PT J AU WALTER, B OVERLAND, JE AF WALTER, B OVERLAND, JE TI AIRCRAFT OBSERVATIONS OF THE MEAN AND TURBULENT STRUCTURE OF THE ATMOSPHERIC BOUNDARY-LAYER DURING SPRING IN THE CENTRAL ARCTIC SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID DRAG COEFFICIENTS; SEA ICE; WAVE AB The NOAA P-3 research aircraft carried out measurements of the mean and turbulence structure of the planetary boundary layer on March 27 and 30, 1989, at 83-degrees-N, 10-degrees-E in the central Arctic. The ice motion was strongly decoupled from the atmosphere; surface winds were 2-3 m s-1 and winds at 100 m were 10 to 12 m s-1 on March 27 and 8 m s-1 on March 30. Geostrophic drag coefficients were 0.014 and 0.015. The mean vertical structure on both days is characterized by a shallow slightly stable layer approximately 50 m deep at the surface with a 300-m-deep strong inversion above. Speed shear was 0.1 s-1 in the slightly stable layer and direction shear at the top of the layer was 15-degrees-20-degrees on March 27 and 35-degrees-40-degrees on March 30. Profiles of the Richardson number for each day showed that Ri was less than 0.25 in the slightly stable layer and rapidly increased above. A low level jet was located at the top of the slightly stable layer just below the level where the Richardson number became very large. Shear-induced turbulence at the top of the slightly stable layer resulted in a maximum of turbulence kinetic energy just below the wind maximum on March 27 and at the wind maximum on March 30. Heat flux profiles from the gust probe measurements showed a maximum of upward flux at the top of the slightly stable layer of 9 W m-2, implying that the flux was countergradient. This upward flux was responsible for maintaining the strength of the inversion above this level. Spectra of turbulent vertical velocity showed a peak at a wavelength of 350-400 m. The source of this peak is gravity waves from an upper level shear layer. It is speculated that the observed countergradient flux was a result of gravity waves and/or wave-turbulence eddy flux. Use of an E-epsilon turbulence closure model allowed an estimation of the sensible heat flux from the air to the snow surface of 4 W m-2. This surface flux played only a secondary role in cooling the surface layer and establishing the structure of the boundary layer compared to inversion layer processes. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. RP WALTER, B (reprint author), SCI APPLICAT INT CORP,13400B NORTHRUP WAY,SUITE 36,BELLEVUE,WA 98005, USA. NR 28 TC 11 Z9 11 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 1991 VL 96 IS C3 BP 4663 EP 4673 DI 10.1029/90JC02263 PG 11 WC Oceanography SC Oceanography GA FC252 UT WOS:A1991FC25200011 ER PT J AU EMERY, WJ FOWLER, CW HAWKINS, J PRELLER, RH AF EMERY, WJ FOWLER, CW HAWKINS, J PRELLER, RH TI FRAM STRAIT SATELLITE IMAGE-DERIVED ICE MOTIONS SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article AB In order to develop an operational method for the U.S. Navy/NOAA Joint Ice Center to extract ice velocity vectors from sequential advanced very high resolution radiometer (AVHRR) imagery, we have combined the maximum cross correlation (MCC) method with a spatial filtering technique on the image inferred ice motion vectors. We compute the cross correlations between images directly from the image brightness values rather than computing FFTs. The direct method allows greater flexibility in computational parameter settings and allows one to compute motion vectors near coastlines where irregular windows are required. By using a combination of statistical and spatial filters we can then retrieve coherent ice motion vectors in the presence of cloud contaminated imagery. A series of six satellite images of the Fram Strait region, from April 1986, was used to compute sea ice motion from pairs of sequential images. The resulting ice motion vectors were taken as a representation of the surface flow field derived objectively from the satellite imagery. Resulting vector motion fields were found to match well with manually tracked vectors for the same images, thus verifying the validity of the objective MCC method of computing ice motion. These techniques were applied to both the visible and infrared AVHRR channels and to images with different spatial resolutions yielding an overall bias accuracy of about 0.5 cm/s and standard deviations of about 0.9 cm/s. The MCC ice motion results were also compared with wind-driven numerical model simulations of the region. Marked differences between the MCC image-derived velocities and those from the numerical model were thought to be primarily due to a stronger ocean current than was present in the model. C1 NATL OCEANOG & ATMOSPHER RES LAB,STENNIS SPACE CTR,MS 39529. RP EMERY, WJ (reprint author), UNIV COLORADO,COLORADO CTR ASTRODYNAM RES,BOX 431,BOULDER,CO 80309, USA. OI Emery, William/0000-0002-7598-9082 NR 16 TC 68 Z9 71 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 1991 VL 96 IS C3 BP 4751 EP 4768 DI 10.1029/90JC02273 PG 18 WC Oceanography SC Oceanography GA FC252 UT WOS:A1991FC25200017 ER PT J AU MAYER, DA MAUL, GA AF MAYER, DA MAUL, GA TI REFINEMENT OF THE STATISTICAL RELATIONSHIP BETWEEN STRAITS OF FLORIDA SEA-LEVEL DIFFERENCE AND FLORIDA-BAHAMAS CABLE VOLTAGES SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Note AB Analyses of a composite 6.5-year record of Bahamas minus Miami sea level difference (SLD) and Florida-Bahamas volume transport determined from submarine cable voltages (CABLE) support the hypothesis advanced by Maul et al. (1990) that SLD is the better variable for monitoring volume transport than western side sea level alone. In the subseasonal frequency band BW1 (393(-1)-182(-1) cycles per day), modeled CABLE, when using SLD, accounts for 79% of the variance of observed CABLE. Further, the phase relationships of modeled CABLE with respect to SLD in BW1 represent approximately a simple time shift in that SLD leads CABLE by a little more than 2 weeks. RP MAYER, DA (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. RI Maul, George/M-1629-2015 OI Maul, George/0000-0001-8413-7853 NR 2 TC 4 Z9 4 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 1991 VL 96 IS C3 BP 4971 EP 4972 DI 10.1029/90JC02352 PG 2 WC Oceanography SC Oceanography GA FC252 UT WOS:A1991FC25200035 ER PT J AU WANG, PS HSU, SM WITTBERG, TN AF WANG, PS HSU, SM WITTBERG, TN TI OXIDATION-KINETICS OF SILICON-CARBIDE WHISKERS STUDIED BY X-RAY PHOTOELECTRON-SPECTROSCOPY SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID NITRIDE; POWDERS AB Silicon carbide whisker surfaces were characterized by X-ray photoelectron spectroscopy (XPS) to determine changes in the surface oxide film which occurred as a result of heating in air at temperatures from 600 to 800-degrees-C. Equations were derived for the calculation of surface oxide film thickness from the SiC to SiO2 2p intensity ratios. Oxidation was found to follow a linear rate law in this temperature range for the first 10 nm of oxide growth. An activation energy of 17.2 +/- 2.8 kcal mol-1 (72 +/- 12 kJ mol-1) was measured. C1 UNIV DAYTON,RES INST,DAYTON,OH 45469. RP WANG, PS (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 11 TC 24 Z9 24 U1 0 U2 3 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD MAR 15 PY 1991 VL 26 IS 6 BP 1655 EP 1658 DI 10.1007/BF00544678 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA FD590 UT WOS:A1991FD59000030 ER PT J AU SCHUUR, TJ SMULL, BF RUST, WD MARSHALL, TC AF SCHUUR, TJ SMULL, BF RUST, WD MARSHALL, TC TI ELECTRICAL AND KINEMATIC STRUCTURE OF THE STRATIFORM PRECIPITATION REGION TRAILING AN OKLAHOMA SQUALL LINE SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID MESOSCALE CONVECTIVE SYSTEM; DOPPLER RADAR ANALYSIS; 10-11 JUNE 1985; THUNDERSTORM ANVIL; STORM; THUNDERCLOUD; CUMULONIMBUS; EVOLUTION; BENEATH; GROWTH AB An electric field sounding through the transition zone precipitation minimum that trailed an Oklahoma squall line on 18 June 1987 provides information about the electrical structure within a midlatitude trailing stratiform cloud. A single-Doppler radar analysis concurrent with the flight depicts a kinematic structure dominated by two mesoscale flow regimes previously identified in squall-line systems: a strong midlevel, front-to-rear flow coinciding with the stratiform cloud layer and a descending rear inflow that sloped from 6.5 km AGL at the stratiform cloud's trailing edge to 1.5 km AGL at the convective line. Electric field magnitudes as high as 113 kV m-1 were observed by the electric field sounding, which reveals an electric field structure comparable in magnitude and complexity to structures reported for convective cells of thunderstorms. The charge regions inferred with an approximation to Gauss' law have charged density magnitudes of 0.2-4.1 nC m-3 and vertical thicknesses of 130-1160 m; these values, too, are comparable to those reported for thunderstorm cells. In agreement with previous studies, an analysis of the lightning data revealed a "bipolar" cloud-to-ground lightning pattern with positive flashes being relatively more common in the stratiform region. From the analysis, we conclude that the stratiform region electrical structure may have been advected from the squall line convective cells as the in-cloud charge regions were primarily found within the front-to-rear flow. Screening layers were found at the lower and upper cloud boundaries. In situ microphysical charging also seems to be a possible source of charge in the stratiform region. We hypothesize that the radar-derived similarities of this system to those previously documented suggests that the newly-documented stratiform electrical structure might also be representative of this type of mesoscale convective system. C1 NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,NORMAN,OK 73069. UNIV OKLAHOMA,COOPERAT INST MESOSCALE METEOROL STUDIES,NORMAN,OK 73019. UNIV MISSISSIPPI,DEPT PHYS,UNIVERSITY,MS 38677. NR 50 TC 45 Z9 47 U1 3 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR 15 PY 1991 VL 48 IS 6 BP 825 EP 842 DI 10.1175/1520-0469(1991)048<0825:EAKSOT>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FG788 UT WOS:A1991FG78800003 ER PT J AU BOETTINGER, WJ AF BOETTINGER, WJ TI THERMODYNAMIC CONSTRAINTS ON NONEQUILIBRIUM SOLIDIFICATION OF ORDERED INTERMETALLIC COMPOUNDS SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 7TH INTERNATIONAL CONF ON RAPIDLY QUENCHED MATERIALS CY AUG 13-17, 1990 CL STOCKHOLM, SWEDEN SP SWEDISH NATL BOARD TECH DIV AB Thermodynamic constraints on permissible values of temperature, liquid compositon, solid composition and long-range order parameter at the freezing interface during non-equilibrium solidification of intermetallic phases are defined in terms of the liquid and solid free energy functions. RP BOETTINGER, WJ (reprint author), NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899, USA. NR 8 TC 1 Z9 1 U1 2 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD MAR 15 PY 1991 VL 133 BP 438 EP 442 DI 10.1016/0921-5093(91)90105-V PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA FG703 UT WOS:A1991FG70300104 ER PT J AU BOETTINGER, WJ BENDERSKY, LA CLINE, J WEST, JA AZIZ, MJ AF BOETTINGER, WJ BENDERSKY, LA CLINE, J WEST, JA AZIZ, MJ TI DISORDER TRAPPING IN NI2TIAL SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 7TH INTERNATIONAL CONF ON RAPIDLY QUENCHED MATERIALS CY AUG 13-17, 1990 CL STOCKHOLM, SWEDEN SP SWEDISH NATL BOARD TECH DIV ID PHASE AB Pulsed laser melting and rapid resolidification can induce disorder trapping in Ni2AlTi at the solidification interface. The alloy formed from the melt with the nonequilibrium B2 structure and subsequently transformed to the equilibrium L2(1) Heusler structure during cooling to room temperature. C1 HARVARD UNIV,CAMBRIDGE,MA 02138. RP BOETTINGER, WJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD, USA. NR 12 TC 22 Z9 22 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD MAR 15 PY 1991 VL 133 BP 592 EP 595 DI 10.1016/0921-5093(91)90142-A PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA FG703 UT WOS:A1991FG70300141 ER PT J AU MILDNER, DFR AF MILDNER, DFR TI NEUTRON INTENSITY GAINS FOR CONVERGING GUIDE SYSTEMS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SUPERMIRROR AB Neutron focusing, or increased current density at the expense of increased beam divergence, can be obtained by the addition of a converging guide at the end of a straight guide. The greatest gains are achieved when the critical angle of the coating of the converging guide is much greater than that of the straight guide. The gain is limited, however, by the increase in angle that the neutron trajectory makes with the axis upon successive reflections. Acceptance diagrams are used for deriving analytical expressions for describing the transmission properties of such systems. The results can be reduced to nine basic formulae depending on the geometric configuration and the coatings of the guides. A graphical method is presented for determining the appropriate expression for the current density gain for a particular guide configuration and relative surface coatings, as a function of wavelength. The results are in agreement with earlier measurements obtained with a straight-converging guide system. RP MILDNER, DFR (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 19 TC 8 Z9 8 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 MAR 15 PY 1991 VL 301 IS 3 BP 395 EP 406 DI 10.1016/0168-9002(91)90003-9 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FH625 UT WOS:A1991FH62500003 ER PT J AU SENGERS, JV VANLEEUWEN, JMJ SCHMIDT, JW AF SENGERS, JV VANLEEUWEN, JMJ SCHMIDT, JW TI CAPILLARY WAVES OF FLUID INTERFACES NEAR A CRITICAL-POINT SO PHYSICA A LA English DT Article ID 3-DIMENSIONAL ISING-MODEL; VAPOR-LIQUID INTERFACE; SURFACE-TENSION; CRITICAL-BEHAVIOR; CRITICAL-TEMPERATURE; FIELD-THEORY; 2-SCALE-FACTOR UNIVERSALITY; REFLECTIVITY MEASUREMENTS; RENORMALIZATION GROUP; COEXISTENCE CURVE AB A fluid interface near a critical point is commonly pictured as an intrinsic interface broadened by thermally excited capillary waves. A comparison of the capillary-wave theory with experiments is hampered by the presence of two short-wavelength cutoff parameters in the theory. We review a procedure introduced earlier for fixing these cutoff parameters, so that a definite comparison can be made with experimental reflectivity data reported by Huang and Webb for a binary liquid (methanol + cyclohexane) near the consolute temperature, and by Wu and Webb for a one-component fluid (sulfurhexafluoride) near the critical temperature. We show that the temperature dependence of the reflectivity data for the binary liquid is consistent with a nonuniversal temperature dependence predicted by capillary-wave theory. The reflectivity data of the vapor-liquid interface of SF6 do not appear to be consistent with the binary-liquid reflectivities and do not show the predicted temperature dependence. C1 NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899. LEIDEN STATE UNIV,INST LORENTZ THEORET NAT,2311 SB LEIDEN,NETHERLANDS. RP SENGERS, JV (reprint author), UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742, USA. NR 65 TC 18 Z9 18 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD MAR 15 PY 1991 VL 172 IS 1-2 BP 20 EP 39 DI 10.1016/0378-4371(91)90309-Z PG 20 WC Physics, Multidisciplinary SC Physics GA FG190 UT WOS:A1991FG19000004 ER PT J AU SCHMIDT, JW AF SCHMIDT, JW TI NEAR-CRITICAL FLUID INTERFACES - A COMPARISON OF THEORY AND EXPERIMENT SO PHYSICA A LA English DT Article ID X-RAY REFLECTIVITY; CAPILLARY WAVES; ELLIPSOMETRIC COEFFICIENT; CRITICAL-POINT; SIMPLE LIQUIDS; SURFACE; TENSION; THICKNESS; LAYER AB Measurements of the ellipticity and the reflectivity of liquid-liquid interfaces in mixtures near their consolute points are compared with theories of the interface. Both sets of measurements yield the same interfacial thickness within experimental error when scaled appropriately by theories that combine both the intrinsic density-profile and capillary-wave aspects of the interface. The theories correctly predict the temperature dependence of the thickness, but systematically overestimate the thickness itself. When the few comparable data for pure fluids are scaled by the same theories, they show an unexpected temperature dependence of the thickness, which is not consistent with the mixture results. RP SCHMIDT, JW (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 35 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD MAR 15 PY 1991 VL 172 IS 1-2 BP 40 EP 52 DI 10.1016/0378-4371(91)90310-9 PG 13 WC Physics, Multidisciplinary SC Physics GA FG190 UT WOS:A1991FG19000005 ER PT J AU CLINTON, TW LYNN, JW AF CLINTON, TW LYNN, JW TI MAGNETIC-ORDERING OF ER IN POWDER AND SINGLE-CRYSTALS OF ERBA2CU3O7 - COMMENT SO PHYSICA C LA English DT Letter ID TEMPERATURE SUPERCONDUCTOR ERBA2CU3O7-DELTA; HEAT C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP CLINTON, TW (reprint author), UNIV MARYLAND,DEPT PHYS,CTR SUPERCOND RES,COLLEGE PK,MD 20742, USA. NR 17 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD MAR 15 PY 1991 VL 174 IS 4-6 BP 487 EP 490 DI 10.1016/0921-4534(91)91587-T PG 4 WC Physics, Applied SC Physics GA FE241 UT WOS:A1991FE24100032 ER PT J AU SCOTT, DA PHELPS, AV AF SCOTT, DA PHELPS, AV TI EXCITATION BY FAST ATOMS AT VERY HIGH ELECTRIC-FIELD TO GAS-DENSITY RATIOS IN ARGON SO PHYSICAL REVIEW A LA English DT Article ID CROSS-SECTIONS; IMPACT EXCITATION; HIGH E/ETA/; COLLISIONS; SPECTROSCOPY; DISCHARGE; EMISSION; AR; IONIZATION; BREAKDOWN AB Measurements of transient and steady-state light emission and of current transients from Ar at very high electric field to gas-density ratios E/n and low gas densities show that the excitation of the 811-nm lines of Ar is primarily by fast neutral Ar atoms. A drift tube with parallel-plane electrodes produces a spatially uniform electric field. Pulsed laser irradiation at 266 nm of the semitransparent cathode produces current pulses of almost-equal-to 10 mA and almost-equal-to 10 ns width. The time and spatial dependences of the line emission at 811 +/- 1 and 750 +/- 1 nm were measured for E/n in the range 280 townsend (Td) to 84 kTd at gas densities from 1.3 x 10(23) to 9 x 10(20) m-3, where 1 Td = 10(-21) V m2. At E/n < 4 kTd the time dependence of the 811-nm emission is consistent with direct and cascade excitation due to electron collisions with Ar. At E/n > 18 kTd the emission transient consists of an early peak caused by the initial electron avalanche followed by a delayed peak that moves toward the cathode with an apparent velocity of about twice that of the ions. Steady-state 811-nm emission is also observed in a region of very low electric field near the cathode where the Ar+ ions have insufficient energy for excitation and the fast atoms are injected from a high-field region. These observations of 811-nm emission, plus previous measurements of steady-state spatial distributions of emission, are interpreted as demonstrating that excitation of the 811-nm lines is primarily by fast Ar atoms formed by charge transfer in Ar+-Ar collisions. For 750-nm emission the prompt portion is much larger and the delayed portion is much weaker than for 811-nm emission showing the importance of excitation by electrons even at these high E/n values. Steady-state observations of 811-nm emission when slow Ar+ ions are injected into a region of high electric field further confirm the model. C1 UNIV COLORADO,NBS,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. NR 49 TC 40 Z9 40 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR 15 PY 1991 VL 43 IS 6 BP 3043 EP 3056 DI 10.1103/PhysRevA.43.3043 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA FD045 UT WOS:A1991FD04500046 ER PT J AU WICKNER, S HOSKINS, J MCKENNEY, K AF WICKNER, S HOSKINS, J MCKENNEY, K TI FUNCTION OF DNAJ AND DNAK AS CHAPERONES IN ORIGIN-SPECIFIC DNA-BINDING BY REPA SO NATURE LA English DT Article ID P1 PLASMID REPLICATION; HEAT-SHOCK PROTEINS; ESCHERICHIA-COLI; GENE AB HEAT-shock proteins are normal constituents of cells whose synthesis is increased on exposure to various forms of stress. They are interesting because of their ubiquity and high conservation during evolution. Two families of heat-shock proteins, hsp60s and hsp70s, have been implicated in accelerating protein folding and oligomerization and also in maintaining proteins in an unfolded state, thus facilitating membrane transport 1-5. The Escherichia coli hsp70 analogue, DnaK, and two other heat-shock proteins, DnaJ and GrpE, are required for cell viability at high temperatures and are involved in DNA replication of phage-lambda and plasmids P1 and F 6-10. These three proteins are involved in replication in vitro of P1 DNA along with many host replication proteins and the P1 RepA initiator protein 11,12. RepA exists in a stable protein complex with DnaJ containing a dimer each of RepA and DnaJ 11. We report here that DnaK and DnaJ mediate an alteration in the P1 initiator protein, rendering it much more active for oriP1 DNA binding. C1 NATL INST STAND & TECHNOL,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. RP WICKNER, S (reprint author), NCI,MOLEC BIOL LAB,BETHESDA,MD 20892, USA. NR 16 TC 190 Z9 191 U1 0 U2 3 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD MAR 14 PY 1991 VL 350 IS 6314 BP 165 EP 167 DI 10.1038/350165a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FB645 UT WOS:A1991FB64500063 PM 2005967 ER PT J AU WILLIAMS, AB HEARD, RW AF WILLIAMS, AB HEARD, RW TI UPOGEBIA-SPINISTIPULA, A NEW BURROWING SHRIMP FROM THE FLORIDA SHELF, NORTHEASTERN GULF OF MEXICO (DECAPODA, THALASSINIDEA, UPOGEBIIDAE) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB Upogebia spinistipula, a new species of burrowing thalassinidean shrimp was taken in box core samples of live bottom material from a sector of the continental shelf in the northeastern Gulf of Mexico that lies off Panama City to Cape Romano, Florida. The rostrum of the small species (carapace length ca. 10 mm) resembles that of U. lepta from the tropical eastern Pacific, the tail fan resembles that of most species of Upogebia in the western hemisphere having an essentially rectangular telson, and the ventrally spined antennular and antennal peduncles resemble those of west Pacific species in the recently described genus Gebiacantha. The species apparently has no close relatives in the western Atlantic. RP WILLIAMS, AB (reprint author), NATL MUSEUM NAT HIST,NATL MARINE FISHERIES SERV SYSTEMAT LAB,WASHINGTON,DC 20560, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD MAR 13 PY 1991 VL 104 IS 1 BP 49 EP 54 PG 6 WC Biology SC Life Sciences & Biomedicine - Other Topics GA FC307 UT WOS:A1991FC30700007 ER PT J AU DELAUDER, S SCHWARZ, FP ATHA, DH AF DELAUDER, S SCHWARZ, FP ATHA, DH TI THERMODYNAMIC ANALYSIS OF HEPARIN BINDING TO ANTITHROMBIN SO FASEB JOURNAL LA English DT Meeting Abstract C1 HOWARD UNIV,DEPT CHEM,WASHINGTON,DC 20059. CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. NATL INST STAND TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 11 PY 1991 VL 5 IS 4 BP A433 EP A433 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA FC207 UT WOS:A1991FC20700362 ER PT J AU WHITMAN, LJ STROSCIO, JA DRAGOSET, RA CELOTTA, RJ AF WHITMAN, LJ STROSCIO, JA DRAGOSET, RA CELOTTA, RJ TI GEOMETRIC AND ELECTRONIC-PROPERTIES OF CS STRUCTURES ON III-V (110) SURFACES - FROM 1D AND 2D INSULATORS TO 3D METALS SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCANNING-TUNNELING MICROSCOPY; ALKALI-METALS; GAAS(110); SI(001)-(2X1); ADSORPTION; TRANSITION AB We report the structural and electronic properties of Cs adsorbed on room-temperature GaAs and InSb (110) surfaces as observed with scanning tunneling microscopy. Cs initially forms long one-dimensional (1D) zigzag chains on both surfaces. Additional Cs adsorption on GaAs(110) results in the formation of a 2D overlayer consisting of five-atom Cs polygons arranged in a c(4 x 4) superlattice. The tunneling gap measured over these insulating structures narrows with the transition from 1D to 2D, with metallic characteristics observed following saturation with a second Cs overlayer. RP WHITMAN, LJ (reprint author), NATL INST STAND & TECHNOL,DIV ELECTRON & OPT PHYS,GAITHERSBURG,MD 20899, USA. RI Whitman, Lloyd/G-9320-2011 OI Whitman, Lloyd/0000-0002-3117-1174 NR 20 TC 182 Z9 183 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 MAR 11 PY 1991 VL 66 IS 10 BP 1338 EP 1341 DI 10.1103/PhysRevLett.66.1338 PG 4 WC Physics, Multidisciplinary SC Physics GA FA692 UT WOS:A1991FA69200023 ER PT J AU TAYLOR, BN COHEN, ER AF TAYLOR, BN COHEN, ER TI HOW ACCURATE ARE THE JOSEPHSON AND QUANTUM HALL-EFFECTS AND QED SO PHYSICS LETTERS A LA English DT Article ID BACKSCATTERING; CONTACTS; ELECTRON AB The accuracy of the theory of the Josephson effect and of the quantum Hall effect is assessed by testing quantitatively the exactness of the theoretically predicted relations K(J) = 2e/h and R(K) = h/e2, where K(J) and R(K) are the phenomenological Josephson and von Klitzing constants, respectively. By assuming the relations are exact, quantum electrodynamics (QED) is tested by comparing QED-dependent and independent values of the fine-structure constant. C1 ROCKWELL INT CORP,CTR SCI,THOUSAND OAKS,CA 91360. RP TAYLOR, BN (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 28 TC 14 Z9 14 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD MAR 11 PY 1991 VL 153 IS 6-7 BP 308 EP 312 DI 10.1016/0375-9601(91)90949-9 PG 5 WC Physics, Multidisciplinary SC Physics GA FD395 UT WOS:A1991FD39500012 ER PT J AU MacLow, MM VANBUREN, D WOOD, DOS CHURCHWELL, E AF MacLow, MM VANBUREN, D WOOD, DOS CHURCHWELL, E TI BOW SHOCK-MODELS OF ULTRACOMPACT H-II REGIONS SO ASTROPHYSICAL JOURNAL LA English DT Article DE INTERSTELLAR MOLECULES; NEBULAE H-II REGIONS; SHOCK WAVES; STARS WINDS ID EARLY-TYPE STARS; MASS-LOSS; BUBBLES; CLOUDS AB We present models of ultracompact H II regions as the bow shocks formed by massive stars, with strong stellar winds, moving supersonically through molecular clouds. The morphologies, sizes, and brightnesses of observed objects match our models well. We provide plausible models for the ultracompact H II regions G12.21-0.1, G29.96-0.02, G34.26 + 0.15, and G43.89-0.78. To do this we begin by calculating the equilibrium shape of the wind-blown shell, assuming momentum conservation. Then we illuminate the shell with ionizing radiation from the central star, perform radiative transfer for free-free emission through the shell, and visualize the resulting object at various angles for comparison with radio continuum maps. Our model unifies most of the observed morphologies of ultracompact H II regions, excluding only those objects with spherical shells. Ram pressure confinement greatly lengthens the life of ultracompact H II regions, explaining the large number that exist in the Galaxy despite their low apparent kinematic ages. C1 NATL INST STAND & TECHNOL, BOULDER, CO USA. UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. CALTECH, JET PROP LAB, CTR INFRARED PROC & ANAL, PASADENA, CA 91109 USA. HARVARD SMITHSONIAN CTR ASTROPHYS, CAMBRIDGE, MA 02138 USA. UNIV WISCONSIN, WASHBURN OBSERV, MADISON, WI 53706 USA. RP MacLow, MM (reprint author), NASA, AMES RES CTR, DIV SPACE SCI, MAIL STOP 245-3, MOFFETT FIELD, CA 94035 USA. OI Mac Low, Mordecai-Mark/0000-0003-0064-4060 NR 31 TC 128 Z9 128 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 10 PY 1991 VL 369 IS 2 BP 395 EP 409 DI 10.1086/169769 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA EY637 UT WOS:A1991EY63700011 ER PT J AU WHITMAN, LJ STROSCIO, JA DRAGOSET, RA CELOTTA, RJ AF WHITMAN, LJ STROSCIO, JA DRAGOSET, RA CELOTTA, RJ TI MANIPULATION OF ADSORBED ATOMS AND CREATION OF NEW STRUCTURES ON ROOM-TEMPERATURE SURFACES WITH A SCANNING TUNNELING MICROSCOPE SO SCIENCE LA English DT Article ID TUNNELLING MICROSCOPE; GAAS(110) SURFACE; DIRECTIONAL WALK AB A general method of manipulating adsorbed atoms and molecules on room-temperature surfaces with the use of a scanning tunneling microscope is described. By applying an appropriate voltage pulse between the sample and probe tip, adsorbed atoms can be induced to diffuse into the region beneath the tip. The field-induced diffusion occurs preferentially toward the tip during the voltage pulse because of the local potential energy gradient arising from the interaction of the adsorbate dipole moment with the electric field gradient at the surface. Depending upon the surface and pulse parameters, cesium (Cs) structures from one nanometer to a few tens of nanometers across have been created in this way on the (110) surfaces of gallium arsenide (GaAs) and indium antimonide (InSb), including structures that do not naturally occur. RP NATL INST STAND & TECHNOL, DIV ELECTRON & OPT PHYS, GAITHERSBURG, MD 20899 USA. RI Whitman, Lloyd/G-9320-2011 OI Whitman, Lloyd/0000-0002-3117-1174 NR 17 TC 244 Z9 244 U1 1 U2 40 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD MAR 8 PY 1991 VL 251 IS 4998 BP 1206 EP 1210 DI 10.1126/science.251.4998.1206 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FA691 UT WOS:A1991FA69100034 PM 17799280 ER PT J AU EKIN, JW SALAMA, K SELVAMANICKAM, V AF EKIN, JW SALAMA, K SELVAMANICKAM, V TI CURRENT RECORD IN SUPERCONDUCTORS SO NATURE LA English DT Letter RP EKIN, JW (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 7 TC 16 Z9 16 U1 0 U2 1 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD MAR 7 PY 1991 VL 350 IS 6313 BP 26 EP 26 DI 10.1038/350026a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA FA693 UT WOS:A1991FA69300042 ER PT J AU GAJEWSKI, E ARUOMA, OI DIZDAROGLU, M HALLIWELL, B AF GAJEWSKI, E ARUOMA, OI DIZDAROGLU, M HALLIWELL, B TI BLEOMYCIN-DEPENDENT DAMAGE TO THE BASES IN DNA IS A MINOR SIDE REACTION SO BIOCHEMISTRY LA English DT Article ID CHROMATOGRAPHY MASS-SPECTROMETRY; STRAND-SCISSION; IRON; ION; OXYGEN; DEGRADATION; MECHANISM; RADICALS; REPAIR; AGENTS AB The antitumor antibiotic bleomycin degrades DNA in the presence of ferric ions and H2O2 or in the presence of ferric ions, oxygen, and ascorbic acid. When DNA degradation is measured as formation of base propenals by the thiobarbituric acid assay, it is not inhibited by superoxide dismutase and scavengers of the hydroxyl radical or by catalase (except that catalase inhibits in the bleomycin/ferric ion/H2O2 system by removing H2O2). Using the technique of gas chromatography/mass spectrometry with selected-ion monitoring, we show that DNA degradation is accompanied by formation of small amounts of modified DNA bases. The products formed are identical with those generated when hydroxyl radicals react with DNA bases. Base modification is significantly inhibited by catalase and partially inhibited by scavengers of the hydroxyl radical and by superoxide dismutase. We suggest that the bleomycin-oxo-iron ion complex that cleaves the DNA to form base propenals can decompose in a minor side reaction to generate hydroxyl radical, which accounts for the base modification in DNA. However, hydroxyl radical makes no detectable contribution to the base propenal formation. C1 NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899. UNIV LONDON KINGS COLL,DEPT BIOCHEM,LONDON WC2R 2LS,ENGLAND. RI Halliwell, Barry/C-8318-2009 NR 41 TC 47 Z9 47 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAR 5 PY 1991 VL 30 IS 9 BP 2444 EP 2448 DI 10.1021/bi00223a021 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA FA348 UT WOS:A1991FA34800021 PM 1705818 ER PT J AU WU, WL AF WU, WL TI ELASTIC-SCATTERING OF POLYMER NETWORKS SO MACROMOLECULES LA English DT Article ID THERMODYNAMICS AB Theoretical aspects of the scattering of cross-linked polymers were investigated with emphasis on the fact that the number of spatial neighbors for any given network is finite. A random-phase approximation scheme was used; however, the number of interactions among spatial neighbors was truncated to account for this finiteness. The result indicates that the expression based on infinite neighbors holds true in all the cases. RP WU, WL (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD MAR 4 PY 1991 VL 24 IS 5 BP 1145 EP 1148 DI 10.1021/ma00005a026 PG 4 WC Polymer Science SC Polymer Science GA FA473 UT WOS:A1991FA47300026 ER PT J AU MAJKRZAK, CF KWO, J HONG, M YAFET, Y GIBBS, D CHIEN, CL BOHR, J AF MAJKRZAK, CF KWO, J HONG, M YAFET, Y GIBBS, D CHIEN, CL BOHR, J TI MAGNETIC RARE-EARTH SUPERLATTICES SO ADVANCES IN PHYSICS LA English DT Review ID X-RAY SCATTERING; DY-Y SUPERLATTICES; SPIN-WAVE DISPERSION; NEUTRON-DIFFRACTION; PHASE-TRANSITIONS; SINGLE-CRYSTAL; THIN-FILMS; GD; HOLMIUM; EXCHANGE AB Advances in molecular beam epitaxy deposition techniques have recently made it possible to grow, an atomic plane at a time, single crystalline superlattices composed of alternating layers of a magnetic rare earth, such as Gd, Dy, Ho, or Er, and metallic Y, which has an identical chemical structure. The primary goal of this article is to review the new and interesting magnetic structures which have been discovered in these novel superlattice systems and to consider what implications the observed phases have on our understanding of the underlying microscopic magnetic interactions. In particular, the effects of the artificial periodicity or compositional modulation, finite layer thickness, and epitaxial strain on the resulting long range magnetic order of Gd-Y, Dy-Y, Ho-Y, Er-Y, and Gd-Dy superlattices are described. C1 AT&T BELL LABS,MURRAY HILL,NJ 07974. BROOKHAVEN NATL LAB,UPTON,NY 11973. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. RISO NATL LAB,DK-4000 ROSKILDE,DENMARK. RP MAJKRZAK, CF (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Hong, Minghwei/C-1433-2010; Bohr, Jakob/A-5819-2012 OI Bohr, Jakob/0000-0003-4076-2045 NR 117 TC 150 Z9 151 U1 2 U2 24 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0001-8732 J9 ADV PHYS JI Adv. Phys. PD MAR-APR PY 1991 VL 40 IS 2 BP 99 EP 189 DI 10.1080/00018739100101482 PG 91 WC Physics, Condensed Matter SC Physics GA FY365 UT WOS:A1991FY36500001 ER PT J AU RUMBLE, J SAUERWEIN, J AF RUMBLE, J SAUERWEIN, J TI THE STANDARD REFERENCE DATABASE SO AMERICAN LABORATORY LA English DT Article RP RUMBLE, J (reprint author), NATL INST STAND & TECHNOL,A323 PHYS BLDG,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT SCIENTIFIC COMMUN INC PI SHELTON PA PO BOX 870, 30 CONTROLS DRIVE, SHELTON, CT 06484-0870 SN 0044-7749 J9 AM LAB JI Am. Lab. PD MAR PY 1991 VL 23 IS 5 BP 81 EP 81 PG 1 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA FA663 UT WOS:A1991FA66300016 ER PT J AU GARDNER, WS STJOHN, PA AF GARDNER, WS STJOHN, PA TI HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD TO DETERMINE AMMONIUM ION AND PRIMARY AMINES IN SEAWATER SO ANALYTICAL CHEMISTRY LA English DT Note ID ORTHO-PHTHALALDEHYDE; ORGANIC NITROGEN; LAKE-MICHIGAN; SUBSTRATE LIMITATION; ACIDS; WATER; BACTERIA; MINERALIZATION; DERIVATIZATION; REGENERATION C1 ST JOHNS ASSOCIATES INC,BELTSVILLE,MD 20705. RP GARDNER, WS (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 33 TC 43 Z9 43 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD MAR 1 PY 1991 VL 63 IS 5 BP 537 EP 540 DI 10.1021/ac00005a032 PG 4 WC Chemistry, Analytical SC Chemistry GA FA188 UT WOS:A1991FA18800034 ER PT J AU OLSON, GJ AF OLSON, GJ TI RATE OF PYRITE BIOLEACHING BY THIOBACILLUS-FERROOXIDANS - RESULTS OF AN INTERLABORATORY COMPARISON SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID MINE DRAINAGE; OXIDATION; BACTERIA; SULFUR; COAL AB Ten laboratories participated in an interlaboratory comparison of determination of bioleaching rates of a pyrite reference material. A standardized procedure and a single strain of Thiobacillus ferrooxidans were used in this study. The mean rate of bioleaching of the pyrite reference material was 12.4 mg of Fe per liter per h, with a coefficient of variation (percent relative standard deviation) of 32% as determined by eight laboratories. These results show the precision among laboratories of the determination of rates of pyrite bioleaching when a standard test procedure and reference material are used. C1 NATL INST STAND & TECHNOL,DIV POLYMER,GAITHERSBURG,MD 20899. NR 19 TC 52 Z9 53 U1 0 U2 1 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD MAR PY 1991 VL 57 IS 3 BP 642 EP 644 PG 3 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA FA764 UT WOS:A1991FA76400004 PM 16348430 ER PT J AU KOHLER, R GEIST, J BONHOURE, J AF KOHLER, R GEIST, J BONHOURE, J TI GENERALIZED PHOTODIODE SELF-CALIBRATION FORMULA SO APPLIED OPTICS LA English DT Article AB We have derived the photodiode self-calibration formula for calculating the internal quantum efficiency of silicon photodiodes from the results of one, two, or three independent self-calibration experiments and from the results of the oxide bias and reverse bias experiments in conjunction with a calculation of the effect of Auger recombination. We show that the formula published elsewhere for these three effects is not correct. C1 BUR INT POIDS & MESURES,F-92312 SEVRES,FRANCE. RP KOHLER, R (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20789, USA. RI Geist, Jon/D-5386-2013; OI Geist, Jon/0000-0001-7749-318X NR 6 TC 1 Z9 1 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD MAR 1 PY 1991 VL 30 IS 7 BP 884 EP 886 PG 3 WC Optics SC Optics GA FA604 UT WOS:A1991FA60400026 PM 20582074 ER PT J AU DIZDAROGLU, M RAO, G HALLIWELL, B GAJEWSKI, E AF DIZDAROGLU, M RAO, G HALLIWELL, B GAJEWSKI, E TI DAMAGE TO THE DNA BASES IN MAMMALIAN CHROMATIN BY HYDROGEN-PEROXIDE IN THE PRESENCE OF FERRIC AND CUPRIC IONS SO ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS LA English DT Article ID CHROMATOGRAPHY MASS-SPECTROMETRY; DEOXYRIBONUCLEIC-ACID; OXYGEN RADICALS; HUMAN-NEUTROPHILS; STRAND SCISSION; SUPEROXIDE; TRANSFORMATION; REPAIR; COPPER; CLEAVAGE C1 UNIV MARYLAND,CATONSVILLE,MD 21228. MARYLAND BIOTECHNOL INST,CTR MED BIOTECHNOL,BALTIMORE,MD 21228. UNIV LONDON KINGS COLL,DEPT BIOCHEM,LONDON WC2R 2LS,ENGLAND. RP DIZDAROGLU, M (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,BLDG 222 B348,GAITHERSBURG,MD 20899, USA. RI Halliwell, Barry/C-8318-2009 NR 42 TC 194 Z9 199 U1 1 U2 16 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0003-9861 J9 ARCH BIOCHEM BIOPHYS JI Arch. Biochem. Biophys. PD MAR PY 1991 VL 285 IS 2 BP 317 EP 324 DI 10.1016/0003-9861(91)90366-Q PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA FA647 UT WOS:A1991FA64700018 PM 1654771 ER PT J AU DIZDAROGLU, M NACKERDIEN, Z CHAO, BC GAJEWSKI, E RAO, G AF DIZDAROGLU, M NACKERDIEN, Z CHAO, BC GAJEWSKI, E RAO, G TI CHEMICAL NATURE OF INVIVO DNA-BASE DAMAGE IN HYDROGEN PEROXIDE-TREATED MAMMALIAN-CELLS SO ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS LA English DT Note ID OXYGEN RADICALS; HUMAN-DISEASE; TRANSFORMATION; MOIETY; IRON C1 NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899. UNIV STELLENBOSCH,DEPT RADIOTHERAPY,TYGERBERG 7505,SOUTH AFRICA. UNIV MARYLAND,CHEM & BIOCHEM ENGN PROGRAM,CATONSVILLE,MD 21228. UNIV MARYLAND,CTR MED BIOTECHNOL,MARYLAND BIOTECHNOL INST,CATONSVILLE,MD 21228. NR 32 TC 104 Z9 110 U1 0 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0003-9861 J9 ARCH BIOCHEM BIOPHYS JI Arch. Biochem. Biophys. PD MAR PY 1991 VL 285 IS 2 BP 388 EP 390 DI 10.1016/0003-9861(91)90378-V PG 3 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA FA647 UT WOS:A1991FA64700030 PM 1654775 ER PT J AU HILL, F GOUGH, D MERRYFIELD, WJ TOOMRE, J AF HILL, F GOUGH, D MERRYFIELD, WJ TOOMRE, J TI SIMULATION OF EFFECTS OF ATMOSPHERIC SEEING ON THE OBSERVATION OF HIGH-DEGREE SOLAR OSCILLATIONS SO ASTROPHYSICAL JOURNAL LA English DT Article DE EARTH, ATMOSPHERE; SUN, OSCILLATIONS ID MODULATION TRANSFER-FUNCTION; MICROTHERMAL MEASUREMENTS; 5-MINUTE OSCILLATIONS; ASTRONOMICAL IMAGES; MOUNTAIN LOCATIONS; POWER SPECTRUM; TURBULENCE; MOTION; ARRIVAL; DESERT AB We have performed numerical simulations of the effects of atmospheric seeing distortions on observations of solar oscillations of intermediate and high degree. The simulations involve a representation of about 100 p-modes of oscillation, with degrees l of 50 to 150 (intermediate-degree) and 150 to 450 (high-degree), formed from the complement of a sexated mode set. These modes are superposed on a steady large-scale convective background, and projected onto the plane of the sky. Image motion is modeled by displacement maps generated from two-dimensional turbulence power spectra; the maps are scaled so that the rms amplitude of the displacements has values of 2" to 5". The distorted velocity field is then Fourier analyzed to produce simulated (l, v) power diagrams, where v is the temporal cyclic frequency. The results show that power in the mode ridges is diminished as atmospheric seeing worsens, particularly at high degrees. Redistribution of power produces an apparent decrease in the frequencies of the oscillations as measured by the centroids of the ridges in the power spectra. We find that time-averaging the observations is quite effective in reducing the noise. C1 UNIV CAMBRIDGE,INST ASTRON,CAMBRIDGE CB3 0HA,ENGLAND. UNIV CAMBRIDGE,DEPT APPL MATH & THEORET PHYS,CAMBRIDGE,ENGLAND. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309. RP HILL, F (reprint author), ASSOC UNIV RES ASTRON INC,NATL OPT ASTRON OBSERV,NATL SOLAR OBSERV,POB 26732,TUCSON,AZ 85726, USA. NR 48 TC 3 Z9 3 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1991 VL 369 IS 1 BP 237 EP 246 DI 10.1086/169754 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA EX523 UT WOS:A1991EX52300023 ER PT J AU BAIK, DH OHR, YG KIM, KS LEE, JM INDELICATO, P KIM, YK AF BAIK, DH OHR, YG KIM, KS LEE, JM INDELICATO, P KIM, YK TI ELECTRIC-DIPOLE, ELECTRIC QUADRUPOLE, AND MAGNETIC DIPOLE TRANSITION-PROBABILITIES OF NA-LIKE IONS, 56 LESS-THAN-OR-EQUAL-TO Z LESS-THAN-OR-EQUAL-TO 92 SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Article ID ISOELECTRONIC SEQUENCE; GAUGE-INVARIANCE C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP BAIK, DH (reprint author), KOREA ATOM ENERGY RES INST,TAEJON 302353,SOUTH KOREA. RI Indelicato, Paul/D-7636-2011 OI Indelicato, Paul/0000-0003-4668-8958 NR 21 TC 23 Z9 23 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0092-640X J9 ATOM DATA NUCL DATA JI Atom. Data Nucl. Data Tables PD MAR PY 1991 VL 47 IS 2 BP 177 EP 203 DI 10.1016/0092-640X(91)90001-K PG 27 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA EZ355 UT WOS:A1991EZ35500001 ER PT J AU SIKDAR, SK COLE, KD STEWART, RM SZLAG, C TODD, P CABEZAS, H AF SIKDAR, SK COLE, KD STEWART, RM SZLAG, C TODD, P CABEZAS, H TI AQUEOUS 2-PHASE EXTRACTION IN BIOSEPARATIONS - AN ASSESSMENT SO BIO-TECHNOLOGY LA English DT Article ID SYSTEMS C1 NATL INST STAND & TECHNOL, CTR CHEM TECHNOL, BOULDER, CO 80303 USA. UNIV ARIZONA, DEPT CHEM ENGN, TUCSON, AZ 85721 USA. RP US EPA, 26 MARTIN LUTHER KING DR, CINCINNATI, OH 45268 USA. NR 24 TC 7 Z9 7 U1 0 U2 5 PU NATURE PUBLISHING GROUP PI NEW YORK PA 75 VARICK ST, 9TH FLR, NEW YORK, NY 10013-1917 USA SN 0733-222X J9 BIO-TECHNOL JI Bio-Technology PD MAR PY 1991 VL 9 IS 3 BP 252 EP + DI 10.1038/nbt0391-252 PG 1 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA FA930 UT WOS:A1991FA93000014 PM 1367300 ER PT J AU HAYES, SP MANGUM, LJ PICAUT, J SUMI, A TAKEUCHI, K AF HAYES, SP MANGUM, LJ PICAUT, J SUMI, A TAKEUCHI, K TI TOGA-TAO - A MOORED ARRAY FOR REAL-TIME MEASUREMENTS IN THE TROPICAL PACIFIC-OCEAN SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID EL NINO; VARIABILITY; CURRENTS; WAVES; ENSO AB The importance of the El Nino-Southern Oscillation phenomenon in year-to-year fluctuations of the global climate has led to efforts to improve the real-time ocean observing system in the tropical Pacific. One element of this improved system is the TOGA-TAO (Tropical Atmosphere-Ocean) Array of wind and upper ocean thermistor chain moorings. This array, the result of an international effort, has already provided the rudiments of a basin-wide, real-time observing system and plans call for a major enhancement during the second half of the TOGA decade. The development of the TAO array is discussed, recent results from the pilot measurements are described, and plans for the expanded array are presented. C1 ORSTOM,INST FRANCAIS RECH SCI DEV COOPERAT,GRP SURTROPAC,NOUMEA,NEW CALEDONIA. HOKKAIDO UNIV,SAPPORO,HOKKAIDO 060,JAPAN. UNIV TOKYO,TOKYO 113,JAPAN. RP HAYES, SP (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 31 TC 255 Z9 257 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 1991 VL 72 IS 3 BP 339 EP 347 DI 10.1175/1520-0477(1991)072<0339:TTAMAF>2.0.CO;2 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FE999 UT WOS:A1991FE99900001 ER PT J AU MERRILL, RT MENZEL, WP BAKER, W LYNCH, J LEGG, E AF MERRILL, RT MENZEL, WP BAKER, W LYNCH, J LEGG, E TI A REPORT ON THE RECENT DEMONSTRATION OF NOAAS UPGRADED CAPABILITY TO DERIVE CLOUD MOTION SATELLITE WINDS SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article C1 NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,ADV SATELLITE PROD PROJECT,WASHINGTON,DC 20233. NOAA,NATL WEATHER SERV,NATL METEOROL CTR,WASHINGTON,DC 20230. NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,SYNOPT ANAL BRANCH,WASHINGTON,DC 20233. RP MERRILL, RT (reprint author), COOPERAT INST METEOROL SATELLITE STUDIES,MADISON,WI, USA. RI Menzel, W. Paul/B-8306-2011 OI Menzel, W. Paul/0000-0001-5690-1201 NR 5 TC 20 Z9 21 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 1991 VL 72 IS 3 BP 372 EP 376 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FE999 UT WOS:A1991FE99900004 ER PT J AU DOSWELL, CA AF DOSWELL, CA TI COMMENTS ON MESOSCALE CONVECTIVE PATTERNS OF THE SOUTHERN HIGH-PLAINS SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Letter RP DOSWELL, CA (reprint author), NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. RI Doswell III, Charles/E-7662-2010 NR 5 TC 10 Z9 10 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 1991 VL 72 IS 3 BP 389 EP 390 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FE999 UT WOS:A1991FE99900009 ER PT J AU EIDELMAN, N CHOW, LC AF EIDELMAN, N CHOW, LC TI EFFECTS OF PH AND CALCIUM ON HYDROLYSIS OF NA2SIF6 AND NA2SNF6 - A QUASI-CONSTANT COMPOSITION TITRATION STUDY SO CARIES RESEARCH LA English DT Article DE HYDROLYSIS; SODIUM HEXAFLUOROSILICATE; SODIUM HEXAFLUOROSTANNATE; TOPICAL FLUORIDE TREATMENT ID ENAMEL; CAHPO4.2H2O; LESIONS AB In the present work, hydrolysis reactions of sodium hexafluorosilicate (Na2SiF6) and sodium hexafluorostannate (Na2SnF6) were studied at various combinations of pH and calcium ion (Ca2+) concentrations using a quasi-constant composition titration method. Under high concentrations of hydrogen ion (H+) and Ca2+, the promoting effect of Ca2+ on the hydrolysis of Na2SiF6 was stronger than the inhibition effect of H+. However, the inhibition effect of H+ on the hydrolysis of Na2SnF6 was stronger than the promoting effect of Ca2+. Na2SiF6 and Na2SnF6 were found to have hydrolysis properties that may make them suitable for use with an acidic calcium phosphate solution in a topical fluoride treatment which forms dicalcium phosphate dihydrate as an intermediate. RP EIDELMAN, N (reprint author), AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. FU NIDCR NIH HHS [DE05354] NR 19 TC 6 Z9 6 U1 1 U2 4 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 0008-6568 J9 CARIES RES JI Caries Res. PD MAR-APR PY 1991 VL 25 IS 2 BP 101 EP 107 PG 7 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA FJ774 UT WOS:A1991FJ77400004 PM 2059971 ER PT J AU BENTZ, DP GARBOCZI, EJ AF BENTZ, DP GARBOCZI, EJ TI PERCOLATION OF PHASES IN A 3-DIMENSIONAL CEMENT PASTE MICROSTRUCTURAL MODEL SO CEMENT AND CONCRETE RESEARCH LA English DT Article ID SILICA FUME; INSULATOR AB A three-dimensional digital-image-based simulation model of cement hydration is used to study the percolation or connectivity of phases as a function of hydration. Results form an investigation of the effects of water-to-cement ratio, degree of hydration, and the substitution of inert and pozzolanic mineral admixtures for cement, on the connectivity of the capillary porosity are presented. For all scenarios studied, plotting pore connectivity vs. total porosity results in a single universal curve. Based on this curve, the degree of hydration required to achieve pore discontinuity as a function of water-to-cement ratio and pozzolanic mineral admixture concentration has been determined. Similar universal curves have been obtained for the connectivity of the calcium silicate hydrate and calcium hydroxide phases in hydrated neat cement when plotted against the appropriate phase fraction. Simulation results are analyzed using percolation theory, and are applied to interprting observed experimental results concerning cement properties as a function of hydration. RP BENTZ, DP (reprint author), NIST,CTR BLDG TECHNOL,DIV BLDG MAT,BLDG 226,ROOM B-348,GAITHERSBURG,MD 20899, USA. NR 25 TC 182 Z9 191 U1 2 U2 20 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD MAR-MAY PY 1991 VL 21 IS 2-3 BP 325 EP 344 DI 10.1016/0008-8846(91)90014-9 PG 20 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA FC640 UT WOS:A1991FC64000014 ER PT J AU GARBOCZI, EJ AF GARBOCZI, EJ TI PERMEABILITY, DIFFUSIVITY, AND MICROSTRUCTURAL PARAMETERS - A CRITICAL-REVIEW - REPLY SO CEMENT AND CONCRETE RESEARCH LA English DT Discussion RP GARBOCZI, EJ (reprint author), NIST,DIV BLDG MAT,B348-226,GAITHERSBURG,MD 20877, USA. NR 0 TC 1 Z9 1 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD MAR-MAY PY 1991 VL 21 IS 2-3 BP 396 EP 396 DI 10.1016/0008-8846(91)90023-B PG 1 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA FC640 UT WOS:A1991FC64000023 ER PT J AU MOUNTAIN, RD THIRUMALAI, D AF MOUNTAIN, RD THIRUMALAI, D TI ERGODIC MEASURES FOR THE SIMULATION OF DIELECTRIC-PROPERTIES OF WATER SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID COMPUTER-SIMULATIONS; MOLECULAR-DYNAMICS; POTENTIALS; CONSTANT; LIQUIDS AB We determine the time interval, t(obs), required for effective ergodic convergence of the fluctuations in dipole moment which are needed for the computation of the dielectric properties of water. It is established that the value of t(obs) can be computed from the scaling relations obeyed by the fluctuation metric, OMEGA-mu(t), associated with the time-averaged values of the dipole moment of the individual water molecules. The theoretical ideas behind OMEGA-mu(t) are used to compute t(obs) at several temperatures for the simple point-charge model of water. It is found that t(obs) increases exponentially with decreasing temperature, the barrier being associated with the difficulty in making collective orientational rearrangements. For the simple point-charge model considered in this paper the barrier for these collective motions is estimated to be 3.5 kcal/mole. This study provides a firm basis for obtaining reliable values of the dielectric properties of dipolar fluids using molecular dynamics simulations. C1 UNIV MARYLAND,DEPT CHEM & BIOCHEM,COLLEGE PK,MD 20742. UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742. RP MOUNTAIN, RD (reprint author), NBS,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 24 TC 14 Z9 15 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD MAR PY 1991 VL 62 IS 2-3 BP 352 EP 359 DI 10.1016/0010-4655(91)90106-U PG 8 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA FF819 UT WOS:A1991FF81900016 ER PT J AU MOUNTAIN, DG AF MOUNTAIN, DG TI THE VOLUME OF SHELF WATER IN THE MIDDLE ATLANTIC BIGHT - SEASONAL AND INTERANNUAL VARIABILITY, 1977-1987 SO CONTINENTAL SHELF RESEARCH LA English DT Article ID SCOTIAN SHELF; NEW-ENGLAND; GULF; SLOPE; MAINE; CIRCULATION; ORIGIN; EDDIES; FRONT; BREAK AB The volume of Shelf Water (salinity < 34 psu) is determined for three regions in the Middle Atlantic Bight (MAB) and for Georges Bank from a combination of hydrographic data and shelf/slope front positions derived from satellite imagery. The hydrographic data were obtained on 49 surveys of the shelf between 1977 and 1987. In each region the shelf water volume exhibits a significant annual cycle with a range of 50-80% of the mean volume. The annual volume cycle appears to be advected southwestward from Georges Bank through the MAB with the mean circulation. Large interannual changes in volume are observed which have a range comparable to the mean volume of Shelf Water in the MAB. Both the seasonal and interannual changes in volume appear to be related to changes in the inflow to the Gulf of Maine through Northeast Channel and from the Scotian Shelf. RP MOUNTAIN, DG (reprint author), NOAA,NATL MARINE FISHERIES SERV,CTR NE FISHERIES,WOODS HOLE,MA 02543, USA. NR 42 TC 34 Z9 34 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD MAR PY 1991 VL 11 IS 3 BP 251 EP 267 DI 10.1016/0278-4343(91)90068-H PG 17 WC Oceanography SC Oceanography GA FH336 UT WOS:A1991FH33600003 ER PT J AU STABENO, PJ REED, RK AF STABENO, PJ REED, RK TI RECENT LAGRANGIAN MEASUREMENTS ALONG THE ALASKAN STREAM SO DEEP-SEA RESEARCH PART A-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID GEOSTROPHIC CIRCULATION MODEL; NORTHEAST PACIFIC; FLOW AB During 1986-87, 26 satellite-tracked drifting buoys were deployed on the shelf in the northern Gulf of Alaska; nine of these buoys entered the Alaskan Stream. The buoy trajectories showed a well-formed, narrow, high-speed current. Southern deviations from the high-speed core were generally wind-induced. All but one of the drifters eventually went aground on one of the Aleutian Islands or entered the Bering Sea. Some meandering of the path of the Alaskan Stream was evident just west of Kodiak Island but was not apparent farther downstream. RP STABENO, PJ (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 17 TC 21 Z9 21 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0198-0149 J9 DEEP-SEA RES PD MAR PY 1991 VL 38 IS 3 BP 289 EP 296 DI 10.1016/0198-0149(91)90069-R PG 8 WC Oceanography SC Oceanography GA FK403 UT WOS:A1991FK40300002 ER PT J AU BAKER, JE EISENREICH, SJ EADIE, BJ AF BAKER, JE EISENREICH, SJ EADIE, BJ TI SEDIMENT TRAP FLUXES AND BENTHIC RECYCLING OF ORGANIC-CARBON, POLYCYCLIC AROMATIC-HYDROCARBONS, AND POLYCHLOROBIPHENYL CONGENERS IN LAKE-SUPERIOR SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ZOOPLANKTON FECAL PELLETS; DEEP-SEA FLOOR; PARTICULATE MATTER; NEPHELOID LAYER; OCEAN; RESUSPENSION; TRANSPORT; MICHIGAN; SORPTION; ONTARIO AB Sediment trap fluxes of solids, organic carbon, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) were measured in Lake Superior in 1984 and 1985. Mass fluxes from surface waters ranged from 0.14 to 1.1 g/m2.day and increased near the lake floor due to resuspension of surficial sediment and horizontal transport in the benthic nepheloid layer. Organic matter fluxes from surface waters ranged from 60 to 90 mg of C/m2.day, with approximately 5% of organic carbon settling from surface waters accumulating in bottom sediments. Concentrations of PCBs and PAHs are enriched 10-100 times on settling particles relative to those on suspended particles. Resultant settling fluxes are 10-100 times greater for several PCB and PAH compounds than net accumulation rates in bottom sediments, indicating the effective and rapid recycling in the benthic region. Biological packaging of organic pollutants into rapidly settling particles is an efficient pathway for the transport of contaminants from surface waters to benthic regions of large lakes. C1 UNIV MINNESOTA,DEPT CIVIL & MINERAL ENGN,MINNEAPOLIS,MN 55455. NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. RI Baker, Joel/A-9685-2011 OI Baker, Joel/0000-0002-9980-7781 NR 57 TC 208 Z9 210 U1 8 U2 40 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAR PY 1991 VL 25 IS 3 BP 500 EP 509 DI 10.1021/es00015a019 PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA EZ643 UT WOS:A1991EZ64300024 ER PT J AU GROSS, EM AF GROSS, EM TI THE HURRICANE DILEMMA IN THE UNITED-STATES SO EPISODES LA English DT Article AB Tropical cyclones, known as hurricanes in the Atlantic and Eastern and Central North Pacific, typhoons in the Western North Pacific, and tropical cyclones elsewhere, are nature's most destructive phenomena. In the USA, hurricanes are categorized and damage is described according to the five categories of the Saffir-Simpson scale on the basis of wind velocity, storm surge, and property damage. Permanent populations of hurricane prone coastal communities are growing, and that coupled with increasing weekend, holiday, and seasonal populations puts large numbers of people at risk. It is increasingly difficult to evacuate these areas because highway development has not kept pace with the population increase. This serves as a strong impetus to develop accurate prediction and warning systems. The technology of modelling the interactions of wind, rain, and storm surge in relation to the topography and of comparing the models with the measured effects of actual hurricanes is improving the prediction and warning systems. However, the rate of forecast improvement continues to lag behind the need. The dilemma is to prevent the complacency caused by false alarms, yet still provide adequate warning times. (Ed.) RP GROSS, EM (reprint author), NOAA,ATMOSPHER SERV BRANCH,WASHINGTON,DC 20230, USA. NR 0 TC 3 Z9 3 U1 2 U2 3 PU INT UNION GEOLOGICAL SCIENCES PI KEYWORTH PA C/O BRITISH GEOLOGICAL SURVEY, KEYWORTH, NOTTINGHAM, ENGLAND NG12 5GG SN 0705-3797 J9 EPISODES JI Episodes PD MAR PY 1991 VL 14 IS 1 BP 36 EP 45 PG 10 WC Geosciences, Multidisciplinary SC Geology GA FX077 UT WOS:A1991FX07700007 ER PT J AU VERGNAT, M HOUSSAINI, S DUFOUR, C BRUSON, A MARCHAL, G MANGIN, P ERWIN, R RHYNE, JJ VETTIER, C AF VERGNAT, M HOUSSAINI, S DUFOUR, C BRUSON, A MARCHAL, G MANGIN, P ERWIN, R RHYNE, JJ VETTIER, C TI DETERMINATION OF SHORT-RANGE MOTION OF HYDROGEN IN AMORPHOUS-SILICON MULTILAYERS BY LOW-ANGLE NEUTRON-SCATTERING SO EUROPHYSICS LETTERS LA English DT Article ID DIFFUSION; INTERDIFFUSION; FILMS; RELAXATION AB The diffusion coefficient of hydrogen in amorphous silicon deposited at 77 K has been measured by monitoring the decay of the low-angle neutron scattering intensity during annealing of Si:H/Si:D/Si:H/Si:D/... multilayers. Diffusion coefficient values ranging from 1.10(-19) cm2/s to 5.10(-19) cm2/s have been obtained for annealing temperatures between 250-degrees-C and 300-degrees-C. These very low values confirm recent experiments of Shinar et al. and show that the motion of hydrogen atoms may be impeded by microstructures in amorphous silicon. C1 INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE,FRANCE. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP VERGNAT, M (reprint author), UNIV NANCY 1,PHYS SOLIDE LAB,CNRS,UA 155,BP 239,F-54506 VANDOEUVRE NANCY,FRANCE. RI Vergnat, Michel/C-5784-2016 OI Vergnat, Michel/0000-0001-5237-9014 NR 23 TC 6 Z9 6 U1 0 U2 2 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD MAR 1 PY 1991 VL 14 IS 5 BP 457 EP 462 DI 10.1209/0295-5075/14/5/012 PG 6 WC Physics, Multidisciplinary SC Physics GA FA318 UT WOS:A1991FA31800012 ER PT J AU FIOCCO, G FUA, D CACCIANI, M DIGIROLAMO, P DELUISI, J AF FIOCCO, G FUA, D CACCIANI, M DIGIROLAMO, P DELUISI, J TI ON THE TEMPERATURE-DEPENDENCE OF POLAR STRATOSPHERIC CLOUDS SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANTARCTIC OZONE HOLE AB Polar stratospheric clouds were frequently observed by lidar at the Amundsen-Scott South Pole Station during May-October 1988. The dependence of the bakscattering cross section on the temperature can be referred to transitions of the HNO3/H2O system: it appears possible to distinguish the pure trihydrate from the mixed ice-trihydrate phase in the composition of the aerosol and, in some cases, to bracket the HNO3 and H2O content of the ambient gas, and to provide indications on the size of the particles. C1 IST FIS ATMOSFERA,CNR,ROME,ITALY. NOAA,GMCC,BOULDER,CO 80303. RP FIOCCO, G (reprint author), UNIV LA SAPIENZA,DIPARTIMENTO FIS,PLE A MORO 2,I-00184 ROME,ITALY. NR 8 TC 7 Z9 7 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR PY 1991 VL 18 IS 3 BP 424 EP 427 DI 10.1029/90GL02585 PG 4 WC Geosciences, Multidisciplinary SC Geology GA FC748 UT WOS:A1991FC74800018 ER PT J AU GALLAWA, RL GOYAL, IC TU, YG GHATAK, AK AF GALLAWA, RL GOYAL, IC TU, YG GHATAK, AK TI OPTICAL WAVE-GUIDE MODES - AN APPROXIMATE SOLUTION USING GALERKINS METHOD WITH HERMITE-GAUSS BASIS FUNCTIONS SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID FOURIER-ANALYSIS; FIBERS AB In Galerkin's method, an orthogonal set of functions is used to convert a differential equation into a set of simultaneous linear equations. We choose the Hermite-Gauss functions as the set of orthogonal basis functions to solve the eigenvalue problem based on the two-dimensional scalar-wave equation subject to the radiation boundary conditions at infinity. The method gives an accurate prediction of modal propagation constant and of the field distribution. The method is tested by using the step-index optical fiber, which has a known exact solution, and the truncated parabolic profile fiber, for which trends are well known. We also test the method using square and elliptic core fibers. The method is found to agree with known results. C1 INDIAN INST TECHNOL,DEPT PHYS,NEW DELHI 10015,INDIA. RP GALLAWA, RL (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 7 TC 34 Z9 38 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD MAR PY 1991 VL 27 IS 3 BP 518 EP 522 DI 10.1109/3.81357 PG 5 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA FR347 UT WOS:A1991FR34700029 ER PT J AU SOUDERS, TM STENBAKKEN, GN AF SOUDERS, TM STENBAKKEN, GN TI CUTTING THE HIGH COST OF TESTING SO IEEE SPECTRUM LA English DT Article RP SOUDERS, TM (reprint author), NATL INST STAND & TECHNOL,WASHINGTON,DC 20234, USA. NR 2 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 SN 0018-9235 J9 IEEE SPECTRUM JI IEEE Spectr. PD MAR PY 1991 VL 28 IS 3 BP 48 EP 51 DI 10.1109/6.67285 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA EZ566 UT WOS:A1991EZ56600017 ER PT J AU CLARK, AF AF CLARK, AF TI HIGHLIGHTS OF THE 1990 APPLIED SUPERCONDUCTIVITY CONFERENCE SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Editorial Material RP CLARK, AF (reprint author), NIST,WASHINGTON,DC 20234, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 814 EP 814 PN 2 PG 1 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY652 UT WOS:A1991EY65200001 ER PT J AU WALSH, T MORELAND, J ONO, RH BEALL, JA CROMAR, M HARVEY, T REINTSEMA, C KALKUR, TS AF WALSH, T MORELAND, J ONO, RH BEALL, JA CROMAR, M HARVEY, T REINTSEMA, C KALKUR, TS TI HIGH CRITICAL-TEMPERATURE SUPERCONDUCTOR TUNNELING SPECTROSCOPY USING SQUEEZABLE ELECTRON-TUNNELING JUNCTIONS SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 APPLIED SUPERCONDUCTIVITY CONF CY SEP 24-28, 1990 CL SNOWMASS, CO SP TELEDYNE WAH CHANG ALBANY, US DOE, HYPRES, GEN DYNAM ID BA-CU-O; THIN-FILMS; SURFACES AB We have performed tunneling spectroscopy measurements on squeezable electron tunneling junctions using Bi-Sr-Ca-Cu-O, Y-Ba-Cu-O, and Nb electrodes in a variety of combinations. A Zero-bias conductance peak has been seen repeatedly in the current-voltage [I(V)] and the conductance-voltage [G(V)] characteristics. We present a model to explain this conductance peak in terms of quasi-particle tunneling, phase diffusion and a supercurrent. Two additional structures have been seen repeatedly in I(V) and G(V). One of these structures has the characteristics of an energy gap feature. The other structure, which can mimic the gap feature, is explained in terms of the switching to the voltage state of a grain boundary junction that is in series with the SET junction. The dependence of these features upon temperature and the force applied to the junction is examined. C1 UNIV COLORADO,BOULDER,CO 80302. UNIV COLORADO,COLORADO SPRINGS,CO 80933. RP WALSH, T (reprint author), NIST,BOULDER,CO 80303, USA. NR 17 TC 2 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 840 EP 843 DI 10.1109/20.133306 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY652 UT WOS:A1991EY65200007 ER PT J AU RUSSEK, SE JEANNERET, B RUDMAN, DA EKIN, JW AF RUSSEK, SE JEANNERET, B RUDMAN, DA EKIN, JW TI PROPERTIES OF YBA2CU3O7-DELTA THIN-FILMS GROWN ON OFF-AXIS-CUT MGO SUBSTRATES SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 APPLIED SUPERCONDUCTIVITY CONF CY SEP 24-28, 1990 CL SNOWMASS, CO SP TELEDYNE WAH CHANG ALBANY, US DOE, HYPRES, GEN DYNAM AB A series of YBa2Cu3O7-delta films has been reactively sputtered on off-axis-cut MgO substrates. All the films were oriented with the c axis normal to the substrate regardless of substrate orientation, indicating that growth dynamics is a major factor influencing film orientation on non-lattice-matched substrates. As the substrate orientation is moved off the [100] direction the films showed a decrease in transition temperature and showed properties indicative of an increased density of weak links. The films grown on high-angle substrates showed better properties than the films grown on low-angle substrates. Films grown on (110) MgO were as good as films grown on (100) MgO. RP RUSSEK, SE (reprint author), NIST,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 9 TC 5 Z9 5 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 931 EP 934 DI 10.1109/20.133331 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY652 UT WOS:A1991EY65200031 ER PT J AU GOODRICH, LF MORELAND, J ROSHKO, A AF GOODRICH, LF MORELAND, J ROSHKO, A TI SWITCHING IN HIGH-TC SUPERCONDUCTOR CURRENT TRANSPORT MEASUREMENTS SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 APPLIED SUPERCONDUCTIVITY CONF CY SEP 24-28, 1990 CL SNOWMASS, CO SP TELEDYNE WAH CHANG ALBANY, US DOE, HYPRES, GEN DYNAM ID MULTIFILAMENTARY SUPERCONDUCTORS AB Switching voltages can occur in four-wire current transport measurements of sintered high-T(c) superconductors. These switching voltages are irreversible shifts in the voltage-current characteristic of the superconductor that result in multiple branches. The voltage along these branches can be very nonlinear as a function of current and can be positive or negative in polarity relative to the current direction. These voltages can interfere with the correct determination of resistivity and critical current density. Experimental data on unaligned sintered Y1Ba2Cu3O7-delta which illustrate the complex nature of the voltages and the confusion they can create are presented. Models based on weak links and H(c)1, and on other effects, are discussed as are observations on NbTi and Nb3Sn based superconductors. RP GOODRICH, LF (reprint author), NIST,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 10 TC 2 Z9 2 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 1194 EP 1197 DI 10.1109/20.133398 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY652 UT WOS:A1991EY65200096 ER PT J AU MORELAND, J RICE, P AF MORELAND, J RICE, P TI TUNNELING STABILIZED MAGNETIC FORCE MICROSCOPY - PROSPECTS FOR LOW-TEMPERATURE APPLICATIONS TO SUPERCONDUCTORS SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 APPLIED SUPERCONDUCTIVITY CONF CY SEP 24-28, 1990 CL SNOWMASS, CO SP TELEDYNE WAH CHANG ALBANY, US DOE, HYPRES, GEN DYNAM AB We have recently demonstrated an imaging technique referred to as tunneling stabilized magnetic force microscopy or TSMFM. TSMFM is performed using a scanning tunneling microscope (STM) with a flexible, magnetic, tunneling tip in place of the usual rigid tunneling tip. TSMFM images are therefore combinations of topography and the magnetic forces between the tip and the sample. Room temperature TSMFM images of magnetic bit tracks on a hard disk have 100 nm resolution and are comparable to Bitter patterns made using a ferrofluid. We have built a low temperature STM with the hope of getting TSMFM images of the flux lattice in superconductors. Preliminary TSMFM images of a YBa2Cu3O(x) (YBCO) film (T(c) = 88 K) in a 50 mT field show that relatively large magnetic forces are acting on the flexible tip while scanning at 48 K. RP MORELAND, J (reprint author), NIST,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 7 TC 8 Z9 8 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 1198 EP 1201 DI 10.1109/20.133399 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY652 UT WOS:A1991EY65200097 ER PT J AU MATTHIESEN, MM GRAYBEAL, JM ORLANDO, TP VANDERSANDE, JB RUDMAN, DA AF MATTHIESEN, MM GRAYBEAL, JM ORLANDO, TP VANDERSANDE, JB RUDMAN, DA TI THE EFFECTS OF ANNEAL TIME AND COOLING RATE ON THE FORMATION AND TEXTURE OF BI2SR2CACU2O8 FILMS SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 APPLIED SUPERCONDUCTIVITY CONF CY SEP 24-28, 1990 CL SNOWMASS, CO SP TELEDYNE WAH CHANG ALBANY, US DOE, HYPRES, GEN DYNAM ID CU-O SYSTEM AB The effects of anneal time and cooling rate on the formation and texturing of superconducting Bi2Sr2CaCu2O8 (BSCCO) films were investigated. Samples were prepared by sputter depositing amorphous BSCCO films, annealing them at 870-degrees-C in flowing 20%O2-80% Ar for 30, 60 or 180 minutes and then cooling them. Two cooling rates were investigated: a fast cool of 80-degrees-C/min and a slow cool of 9-degrees-C/min. It was observed that effective coupling between superconducting 2212 grains occurs when films exhibit a minimum amount of (00-iota) texturing. In addition, the nucleation and growth kinetics are significantly different for the isothermal and cooling regimes of thermal processing. Consequently, anneal time and cooling rate play distinct roles in the achievement of the appropriate texture and microstructure in the films: longer anneal times increase the volume fraction of the 2212 phase while slower cooling rates enhance grain growth and texturing. C1 NIST,CRYOELECTR METROL GRP,BOULDER,CO 80303. RP MATTHIESEN, MM (reprint author), MIT,CTR MAT SCI & ENGN,CAMBRIDGE,MA 02139, USA. NR 8 TC 2 Z9 2 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 1223 EP 1227 DI 10.1109/20.133406 PN 2 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY652 UT WOS:A1991EY65200103 ER PT J AU ONO, RH BEALL, JA HARVEY, TE REINTSEMA, CD JOHANSSON, M CROMAR, MW GOODRICH, LF MORELAND, J ROSHKO, A STAUFFER, TC AF ONO, RH BEALL, JA HARVEY, TE REINTSEMA, CD JOHANSSON, M CROMAR, MW GOODRICH, LF MORELAND, J ROSHKO, A STAUFFER, TC TI CRITICAL CURRENT BEHAVIOR OF AG-COATED YBA2CU3O7-X THIN-FILMS SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 APPLIED SUPERCONDUCTIVITY CONF CY SEP 24-28, 1990 CL SNOWMASS, CO SP TELEDYNE WAH CHANG ALBANY, US DOE, HYPRES, GEN DYNAM ID HIGH-TC AB We have studied the behavior of high-quality YBa2Cu3O7-x (YBCO) thin films with Ag over-layers. We chose to study Ag in detail because of its widespread use as contact metalization and our earlier studies of proximity effects in YBCO. The details of transport critical current measurements are presented. The Ag coatings can reduce normal state resistance while not degrading the critical current density, J(c). RP ONO, RH (reprint author), NIST,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 1471 EP 1474 DI 10.1109/20.133461 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY652 UT WOS:A1991EY65200164 ER PT J AU LUO, J JIANG, XP CHOW, HM CIMA, MJ GRAYBEAL, JM ORLANDO, TP RUDMAN, DA AF LUO, J JIANG, XP CHOW, HM CIMA, MJ GRAYBEAL, JM ORLANDO, TP RUDMAN, DA TI GRAIN ALIGNMENT AND TRANSPORT-PROPERTIES OF BI2SR2CACU2O8 GROWN BY LASER-HEATED FLOAT ZONE METHOD SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 APPLIED SUPERCONDUCTIVITY CONF CY SEP 24-28, 1990 CL SNOWMASS, CO SP TELEDYNE WAH CHANG ALBANY, US DOE, HYPRES, GEN DYNAM ID ANGULAR-DEPENDENCE; BI2.2SR2CA0.8CU2O8+DELTA; FIELD AB Single phase Bi2Sr2CaCu2O8 bulk superconductor (T(c) congruent-to 82 K) has been grown by laser-heated float zone method. The samples are highly textured with the grains, typically 100 mu-m in diameter and 0.5 cm long, elongated along the crystal a-axis which is the preferred growth direction. Our X-ray analysis and transport measurements indicate that all three principle axes (a,b,c) are orientated from grain to grain. The upper limit of the misalignment between the grains is estimated to be less that 2 degrees from the measured anisotropy ratio. The critical current density for such highly textured polycrystalline samples is anisotropic and limited mainly by the weak links at the grain boundaries. The grain boundary effects will be discussed on the basis of the measured temperature and magnetic field dependence of the critical current. C1 MIT,DEPT MAT SCI & ENGN,CAMBRIDGE,MA 02139. MIT,DEPT PHYS,CAMBRIDGE,MA 02139. MIT,DEPT ELECT ENGN & COMP SCI,CAMBRIDGE,MA 02139. NIST,CRYOELECTR METROL GRP,BOULDER,CO 80803. RP LUO, J (reprint author), MIT,FRANCIS BITTER NATL MAGNET LAB,CAMBRIDGE,MA 02139, USA. NR 13 TC 1 Z9 1 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 1499 EP 1502 DI 10.1109/20.133467 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY652 UT WOS:A1991EY65200169 ER PT J AU BEALL, JA CROMAR, MW HARVEY, TE JOHANSSON, ME ONO, RH REINTSEMA, CD RUDMAN, DA ASHER, SE NELSON, AJ SWARTZLANDER, AB AF BEALL, JA CROMAR, MW HARVEY, TE JOHANSSON, ME ONO, RH REINTSEMA, CD RUDMAN, DA ASHER, SE NELSON, AJ SWARTZLANDER, AB TI YBA2CU3O7-DELTA INSULATOR MULTILAYERS FOR CROSSOVER FABRICATION SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 APPLIED SUPERCONDUCTIVITY CONF CY SEP 24-28, 1990 CL SNOWMASS, CO SP TELEDYNE WAH CHANG ALBANY, US DOE, HYPRES, GEN DYNAM AB The development of thin-film dielectrics compatible with the epitaxial growth of YBa2Cu3O7-delta (YBCO) is crucial to the fabrication of multilayer device and circuit structures. We have investigated the YBCO/SrTiO3(STO) system by fabricating YBCO/STO bilayers and simple YBCO/STO/YBCO crossover structures. The thin films were deposited in situ by pulsed laser deposition and analyzed using x-ray diffraction and scanning electron microscopy. The film interfaces were characterized by secondary ion mass spectrometry (SIMS) depth profiling. We have developed photolithographic and wet-etching processes for patterning the crossovers which are compatible with these materials. The crossover structures were characterized by resistance and insulator pinhole density as well as the superconducting properties of the patterned top and bottom YBCO electrodes (critical temperature, T(c) and critical current density, J(c)). Using SrTiO3 as the insulating layer, we have made crossovers with good isolation between layers( > 100 M OMEGA) and high J(c) even in the top electrode (J(c)(76 K) > 10(5) A/cm2). C1 SOLAR ENERGY RES INST,GOLDEN,CO 80401. RP BEALL, JA (reprint author), NIST,CRYOELECTR METROL GRP,DIV ELECTROMAGNET TECHNOL,MS 72403,325 BROADWAY,BOULDER,CO 80303, USA. NR 6 TC 11 Z9 11 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 1596 EP 1599 DI 10.1109/20.133491 PN 2 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY652 UT WOS:A1991EY65200192 ER PT J AU ROSHKO, A ONO, RH BEALL, JA MORELAND, J NELSON, AJ ASHER, SE AF ROSHKO, A ONO, RH BEALL, JA MORELAND, J NELSON, AJ ASHER, SE TI MORPHOLOGY OF SILVER ON YBA2CU3O7-DELTA THIN-FILMS SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 APPLIED SUPERCONDUCTIVITY CONF CY SEP 24-28, 1990 CL SNOWMASS, CO SP TELEDYNE WAH CHANG ALBANY, US DOE, HYPRES, GEN DYNAM AB The morphology of silver layers deposited and annealed on laser ablated YBa2Cu3O7-delta films has been examined. Silver was found to dewet the YBa2Cu3O7-delta (001) surface on annealing in oxygen and nitrogen. This dewetting behavior may be kineticly inhibited by using either thick silver layers or short anneals and low temperatures. Silver layers 70 nm to 2.5 mu-m thick were studied on films deposited on SrTiO3, LaA10(3) and MgO substrates. Anneal times were varied from 6.5 min to 15 hrs at temperatures from 200 to 700-degrees-C. C1 SOLAR ENERGY RES INST,GOLDEN,CO 80401. RP ROSHKO, A (reprint author), NIST,325 BROADWAY,BOULDER,CO 80303, USA. NR 7 TC 8 Z9 9 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 1616 EP 1618 DI 10.1109/20.133984 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY652 UT WOS:A1991EY65200197 ER PT J AU CROSS, RW GOLDFARB, RB AF CROSS, RW GOLDFARB, RB TI HALL PROBE MAGNETOMETER FOR SSC MAGNET CABLES - EFFECT OF TRANSPORT CURRENT ON MAGNETIZATION AND FLUX CREEP SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 CONF ON APPLIED SUPERCONDUCTIVITY CY SEP 24-28, 1990 CL SNOWMASS, CO ID FIELDS AB We constructed a Hall probe magnetometer to measure the magnetization hysteresis loops of Superconducting Super Collider magnet cables. The instrument uses two Hall-effect field sensors to measure the applied field H and the magnetic induction B. Magnetization M is calculated from the difference of the two quantities. The Hall probes are centered coaxially in the bore of a superconducting solenoid with the B probe against the sample's broad surface. An alternative probe arrangement, in which M is measured directly, aligns the sample probe parallel to the field. We measured M as a function of H and field cycle rate both with and without a dc transport current. Flux creep as a function of current was measured from the dependence of ac loss on the cycling rate and from the decay of magnetization with time. Transport currents up to 20% of the critical current have minimal effect on magnetization and flux creep. RP CROSS, RW (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. RI Goldfarb, Ronald/A-5493-2011 OI Goldfarb, Ronald/0000-0002-1942-7974 NR 14 TC 9 Z9 9 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 1796 EP 1798 DI 10.1109/20.133540 PN 3 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY653 UT WOS:A1991EY65300029 ER PT J AU PETERSEN, TW GOLDFARB, RB AF PETERSEN, TW GOLDFARB, RB TI EFFECT OF MECHANICAL DEFORMATION ON NB-TI FILAMENT PROXIMITY-EFFECT COUPLING AT THE EDGES OF SSC CABLES SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 CONF ON APPLIED SUPERCONDUCTIVITY CY SEP 24-28, 1990 CL SNOWMASS, CO ID STRANDS; MAGNETS; FIELDS AB Magnetization as a function of transverse magnetic field and time was measured for short strands extracted from the centers and edges of five Nb-Ti Rutherford cables designed for use in Superconducting Super Collider dipole magnets. The multifilamentary strands all had 6-mu-m diameter filaments. Edge samples, which had severe mechanical deformation, showed small magnetic coupling losses at low fields, compared to no coupling losses for undeformed center strands. Sharp strand bends at cable edges decreases the interfilament spacing to the order of the coherence length in the normal matrix material which increases the effective filament diameter and hysteresis loss at low fields. Microscopic studies of the cables' cross sections confirmed smaller interfilament separations in these samples. Flux creep measurements, represented by the time dependence of magnetization, showed little difference between edge and center samples. This indicates that the proximity-coupled matrix in edge samples is not a significant source of flux creep. RP PETERSEN, TW (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. RI Goldfarb, Ronald/A-5493-2011 OI Goldfarb, Ronald/0000-0002-1942-7974 NR 9 TC 2 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 1809 EP 1810 DI 10.1109/20.133544 PN 3 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY653 UT WOS:A1991EY65300033 ER PT J AU GROSSMAN, EN MCDONALD, DG SAUVAGEAU, JE AF GROSSMAN, EN MCDONALD, DG SAUVAGEAU, JE TI FAR-INFRARED KINETIC-INDUCTANCE DETECTORS SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 CONF ON APPLIED SUPERCONDUCTIVITY CY SEP 24-28, 1990 CL SNOWMASS, CO ID DC SQUIDS; SUPERCONDUCTORS; QUASIPARTICLE; PHONON; FILMS AB Extremely sensitive far-infrared detectors suitable for both direct detection and heterodyne applications are possible based upon mu-m-sized thin films with thickness less than a superconducting penetration depth. The penetration depth of such a film, and therefore its inductance, varies with temperature and with quasiparticle population (described by an effective temperature T*), resulting in both bolometric and non-equilibrium "photoinductive" responses. Incident radiation is coupled into the small-area kinetic inductor by a lithographic antenna, and the resulting inductance changes are amplified and converted to a voltage signal by an integrated microstrip DC SQUID. The device is sensitive because, unlike junction-based devices with large capacitive reactances, the kinetic inductor is naturally well matched to the antenna impedance at the far-IR frequency (nu > 2-DELTA/h), and to the pre-amplifier (SQUID) impedance at microwave or video frequencies (nu << 2-DELTA/h). The best kinetic inductor materials are those with low electronic mean free path, large penetration depth, and high critical current density. Thus, common magnet alloys such as NbTi are the natural choice for liquid-He temperature operation. A detailed analysis predicts a (phonon-limited) NEP of 4x10(-17) W/square-root Hz for a bolometer with an iridium kinetic inductor operated at 0.1 K. A heterodyne noise temperature of 2250 K (single-sideband) at 3 THz, with 200 MHz bandwidth, is predicted for a Nb-Ti mixer with a operated at 4 K. RP GROSSMAN, EN (reprint author), NATL INST STAND & TECHNOL,72403,BOULDER,CO 80309, USA. NR 12 TC 29 Z9 29 U1 2 U2 11 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 2677 EP 2680 DI 10.1109/20.133763 PN 4 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY654 UT WOS:A1991EY65400033 ER PT J AU SAUVAGEAU, JE MCDONALD, DG GROSSMAN, EN AF SAUVAGEAU, JE MCDONALD, DG GROSSMAN, EN TI SUPERCONDUCTING KINETIC INDUCTANCE RADIOMETER SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 CONF ON APPLIED SUPERCONDUCTIVITY CY SEP 24-28, 1990 CL SNOWMASS, CO AB We are developing a bolometer based on a differential thermometer that senses temperature changes through changes in the kinetic inductance of a superconducting thin film. The temperature transducer is an inductance bridge patterned as an integrated circuit on a 1 cm2 Si substrate. Two inductors from opposite arms of the bridge are patterned on a 2 mm2 thermally isolated Si island which is supported by a 9-mu-m thick Si:B membrane. The bridge is excited with audio frequency current and the bridge imbalance is detected with a commercial DC SQUID amplifier. The bridge is balanced by applying power to the thermally isolated island. This thermometer is the sensor for a prototype radiometer that will provide an absolute measure of IR power. The radiometer, which is designed for a NEP of about 10(-11) W/square-root Hz, is intended to measure the spectrally dispersed power of a 300 K black body. This absolute radiometer is being developed for use at the Low Background Infrared (LBIR) Facility at NIST, Gaithersburg. The noise floor of the temperature transducer for the radiometer has been measured to be 0.7 pW for a 100 s integration time. This is approximately 150 times lower noise than that of the commercial absolute radiometer currently used at the LBIR Facility in Gaithersburg. RP SAUVAGEAU, JE (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 3 TC 20 Z9 20 U1 1 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 2757 EP 2760 DI 10.1109/20.133782 PN 4 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY654 UT WOS:A1991EY65400052 ER PT J AU MILLER, DL PRZYBYSZ, JX KANG, J HAMILTON, CA BURNELL, DM AF MILLER, DL PRZYBYSZ, JX KANG, J HAMILTON, CA BURNELL, DM TI JOSEPHSON COUNTING ANALOG-TO-DIGITAL CONVERTER SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 CONF ON APPLIED SUPERCONDUCTIVITY CY SEP 24-28, 1990 CL SNOWMASS, CO ID DC SQUIDS; NOISE AB A superconductive analog-to-digital converter which uses a dc SQUID as a quantizer and a flip-flop counter as a digitizer has been designed, fabricated, and tested. The circuit was fabricated using a ten-level niobium process. Tests at 4.2K demonstrated (1) counting to the full twelve-bit accuracy of the design, (2) monotonic A/D conversion with linearity to less than 1 LSB over the more than nine-bit range of conversion, (3) read-on-the-fly operation with counter overflow, and (4) counter operation with a gate current bus. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. WESTINGHOUSE ELECT CORP,ADV TECHNOL LABS,BALTIMORE,MD 21203. RP MILLER, DL (reprint author), WESTINGHOUSE ELECT CORP,CTR SCI & TECHNOL,PITTSBURGH,PA 15235, USA. NR 12 TC 17 Z9 17 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 2761 EP 2764 DI 10.1109/20.133783 PN 4 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY654 UT WOS:A1991EY65400053 ER PT J AU SOULEN, RJ FOGLE, WE COLWELL, JH AF SOULEN, RJ FOGLE, WE COLWELL, JH TI SYSTEMATIC STUDIES OF THE EFFECT OF A BANDPASS FILTER ON A JOSEPHSON-JUNCTION NOISE THERMOMETER SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 CONF ON APPLIED SUPERCONDUCTIVITY CY SEP 24-28, 1990 CL SNOWMASS, CO AB We present the results of an extensive study of the effect of a filter upon the performance of a resistive SQUID noise thermometer used to define an absolute temperature scale below 1 K. Agreement between the model for this effect and the experimental results indicates that the temperature scale defined by this noise thermometer is accurate to 0.1%. C1 USN,RES LAB,WASHINGTON,DC 20375. RP SOULEN, RJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 2920 EP 2923 PN 4 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY654 UT WOS:A1991EY65400092 ER PT J AU WELTY, RP MARTINIS, JM AF WELTY, RP MARTINIS, JM TI A SERIES ARRAY OF DC SQUIDS SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 CONF ON APPLIED SUPERCONDUCTIVITY CY SEP 24-28, 1990 CL SNOWMASS, CO ID PERFORMANCE AB We have fabricated a series array of 100 dc SQUIDs using trilayer Nb-AlO(x)-Nb junctions. The SQUIDs are modulated with a common flux bias line and produce an output voltage swing of several millivolts across the array. The large output voltage will allow direct connection to room temperature electronics without the transformer coupling and resulting frequency limitations commonly associated with dc SQUID amplifiers. We have measured a bandwidth of dc to at least 175 MHz for a 100-SQUID array. The series array will be used as the output stage for a multistage integrated SQUID amplifier. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP WELTY, RP (reprint author), UNIV COLORADO,DEPT ELECT ENGN,BOULDER,CO 80309, USA. NR 9 TC 127 Z9 128 U1 1 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 2924 EP 2926 DI 10.1109/20.133821 PN 4 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY654 UT WOS:A1991EY65400093 ER PT J AU PARK, GS CUNNINGHAM, CE CABRERA, B HUBER, ME AF PARK, GS CUNNINGHAM, CE CABRERA, B HUBER, ME TI TRAPPED VORTICES IN A SUPERCONDUCTING MICROBRIDGE SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 CONF ON APPLIED SUPERCONDUCTIVITY CY SEP 24-28, 1990 CL SNOWMASS, CO ID FREQUENCY NOISE-REDUCTION; SWITCH AB Laser light pulsed onto a Nb microbridge drives it momentarily normal and changes the quantum flux state of a superconducting inductive loop. The flux state is measured by a SQUID coupled to the loop. With a Nd:YAG laser, vortices are never trapped in the microbridge; with a diode laser, vortices are sometimes trapped. The spatial distribution of the trapped flux was studied. The effect of the optical pulse fall time on the frequency of flux trapping was found to be unimportant from 200 ns to 8 ms. Noise spectrum analysis indicates that the laser diode is 5 to 25 times noisier than the Nd:YAG laser at the characteristic frequency of the loop. This noise is believed to be responsible for flux trapping in the microbridge. C1 NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303. RP PARK, GS (reprint author), STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305, USA. RI Huber, Martin/B-3354-2011 NR 6 TC 5 Z9 5 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 3021 EP 3024 DI 10.1109/20.133846 PN 4 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY654 UT WOS:A1991EY65400118 ER PT J AU AVRIN, WF SIMMONDS, MB HAMILTON, CA AF AVRIN, WF SIMMONDS, MB HAMILTON, CA TI MICROCHIP DESIGN FOR A LOW-FREQUENCY JOSEPHSON-ARRAY VOLTAGE STANDARD SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 CONF ON APPLIED SUPERCONDUCTIVITY CY SEP 24-28, 1990 CL SNOWMASS, CO AB The complexity of the Josephson-array voltage standard can be reduced by using lower-frequency microwaves to excite the junction array. For operation at reduced frequencies, the designs of the array must take into account the large size of the junctions, as well as the perturbing effect of the junction reactance on the distribution of microwave power. Such issues are especially important when durable, but low-capacitance, trilayer junctions are used in the array. These problems are minimized by a new design, in which the junction array is wound into a continuous spiral. C1 NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303. RP AVRIN, WF (reprint author), QUANTUM MAGNET INC,11578 SORRENTO VALLEY RD,SAN DIEGO,CA 92121, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 3359 EP 3362 DI 10.1109/20.133932 PN 4 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY654 UT WOS:A1991EY65400202 ER PT J AU BOCKO, MF ZHANG, ZN MARTINET, S CROMAR, MW AF BOCKO, MF ZHANG, ZN MARTINET, S CROMAR, MW TI A PHASE SENSITIVE SIS MIXER TO CIRCUMVENT THE QUANTUM LIMIT SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1990 CONF ON APPLIED SUPERCONDUCTIVITY CY SEP 24-28, 1990 CL SNOWMASS, CO ID NOISE AB A conventional SIS mixer, which is pumped by a single frequency local oscillator (LO) functions as a phase-insensitive linear amplifier and may achieve a noise level near the "quantum limit" of one-half photon added noise per unit bandwidth. A phase sensitive linear amplifier may have less noise than this "quantum limit". We are attempting to beat the quantum noise limit with an SIS mixer by employing a two-LO technique which makes the mixer's gain dependent upon the phase of the incoming signal. We have experimentally demonstrated the phase sensitive gain of our two-LO mixer; the gain variation from maximum to minimum is more than 20 dB. We also present theoretical predictions of the noise of the two-LO mixer. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. RP BOCKO, MF (reprint author), UNIV ROCHESTER,DEPT ELECT ENGN,ROCHESTER,NY 14627, USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD MAR PY 1991 VL 27 IS 2 BP 3391 EP 3394 DI 10.1109/20.133940 PN 4 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA EY654 UT WOS:A1991EY65400209 ER PT J AU SIDHU, SS KIEFER, JH LIFSHITZ, A TAMBURU, C WALKER, JA TSANG, W AF SIDHU, SS KIEFER, JH LIFSHITZ, A TAMBURU, C WALKER, JA TSANG, W TI RATE OF THE RETRO-DIELS-ALDER DISSOCIATION OF 1,2,3,6-TETRAHYDROPYRIDINE OVER A WIDE TEMPERATURE-RANGE SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID METHYLENEIMINE CH2=NH; GAS-PHASE; CYCLOHEXENE; DECOMPOSITION; MOLECULES; KINETICS; MINDO-3; STATES; BEAM AB Rate constants for the retro-Diels-Alder dissociation of 1,2,3,6-tetrahydropyridine, to 1,3-butadiene and methanimine, have been measured over 650-1450 K. To cover this range, three separate techniques were used at three laboratories: laser schlieren and single pulse shock tube methods, and a comparative rate flow system technique. The derived rate constants are extrapolated to the high-pressure limit with an RRKM model parameterized to fit the falloff observed in the laser-schlieren measurements. The resulting high-pressure rate constants show a reduction in activation energy of about 10 kcal/mol, comparing the isoelectronic cyclohexene, but little change in A-factor. There is an apparent increase in activation energy of 4 kcal/mol over the temperature range of these experiments, which is just outside probable error. Such a rise in activation energy is in marked contrast to the drop usually seen in simple bond fission, and may reflect a change from a concerted to a stepwise, biradical mechanism at high temperatures. C1 HEBREW UNIV JERUSALEM,DEPT PHYS CHEM,IL-91904 JERUSALEM,ISRAEL. NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. RP SIDHU, SS (reprint author), UNIV ILLINOIS,DEPT CHEM ENGN,CHICAGO,IL 60680, USA. NR 33 TC 7 Z9 7 U1 2 U2 7 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD MAR PY 1991 VL 23 IS 3 BP 215 EP 227 DI 10.1002/kin.550230304 PG 13 WC Chemistry, Physical SC Chemistry GA FC618 UT WOS:A1991FC61800003 ER PT J AU CATRON, BA RAY, SR AF CATRON, BA RAY, SR TI ALPS - A LANGUAGE FOR PROCESS SPECIFICATION SO INTERNATIONAL JOURNAL OF COMPUTER INTEGRATED MANUFACTURING LA English DT Article AB This paper describes research identifying information models to facilitate process specification and to transfer this information to process control. A conceptual schema is introduced as a means to bridge the gap between process planning requirements and production control requirements. The result is a process specification language based on directed graph notation which allows full specification of parallel activities, event synchronization, alternative processes, resource management, and task decomposition. RP CATRON, BA (reprint author), NATL INST STAND & TECHNOL,DIV FACTORY AUTOMAT SYST,GAITHERSBURG,MD 20899, USA. NR 21 TC 46 Z9 48 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0951-192X J9 INT J COMP INTEG M JI Int. J. Comput. Integr. Manuf. PD MAR-APR PY 1991 VL 4 IS 2 BP 105 EP 113 DI 10.1080/09511929108944485 PG 9 WC Computer Science, Interdisciplinary Applications; Engineering, Manufacturing; Operations Research & Management Science SC Computer Science; Engineering; Operations Research & Management Science GA FU105 UT WOS:A1991FU10500006 ER PT J AU KAISER, B LAESECKE, A STELBRINK, M AF KAISER, B LAESECKE, A STELBRINK, M TI MEASUREMENTS OF THE VISCOSITY OF LIQUID TOLUENE IN THE TEMPERATURE-RANGE 218-378-K SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE CAPILLARY VISCOMETER; VISCOSITY; TOLUENE ID BINARY-MIXTURES; HYDROCARBONS; HEXANE; WATER AB New relative measurements of the viscosity of liquid toluene are reported for the temperature range 218 to 378 K. They supplement the existing data, which have been obtained mostly above 273.15 K. The relative accuracy of the results is estimated between - 1 and 1.38% at 218 K, narrowing to one of -0.74 and 1.12% at 378 K. The experimental data have been correlated well within these estimates by an empirical temperature function. A comparison with previous experimental and compiled or evaluated data includes references since 1894 and is the most comprehensive survey so far. The agreement with the present data is generally very good. There is a need for further measurements with instruments other than capillary viscometers and in the low-temperature range from the triple point (178.15 K) to 273.15 K. C1 NATL INST STANDARDS & TECHNOL,DIV THERMOPHYS,325 BROADWAY,BOULDER,CO 80303. UNIV SIEGEN,INST FLUID & THERMODYNAM,W-5900 SIEGEN,GERMANY. NR 47 TC 28 Z9 29 U1 1 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD MAR PY 1991 VL 12 IS 2 BP 289 EP 306 DI 10.1007/BF00500753 PG 18 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA FC434 UT WOS:A1991FC43400006 ER PT J AU SANBORN, HR MISITANO, DA AF SANBORN, HR MISITANO, DA TI HORMONALLY INDUCED SPAWNING OF ENGLISH SOLE (PAROPHRYS-VETULUS GIRARD) SO JOURNAL OF APPLIED ICHTHYOLOGY-ZEITSCHRIFT FUR ANGEWANDTE ICHTHYOLOGIE LA English DT Article AB The effectiveness of carp pituitary extract (CPE) and luteinizing hormone-releasing hormone analog 'a' (LHRHa) to stimulate English sole (Parophrys vetulus) to complete gonadal maturation was evaluated. This treatment was necessary because untreated ripe female English sole, which cannot be spawned within a few days of capture, will discontinue gonadal maturation. In the present study, fish captured at various stages of gonadal maturation were treated with either daily injections of CPE (1 mg/kg body weight) or injections of LHRHa (0.15 mg/kg body weight) every 4 days. The results were evaluated by comparison of measures of reproductive success (percent fertilization and percent normal larvae) between the treated fish and fish spawned immediately after capture. Both CPE and LHRHa induced gonadal maturation in laboratory-held English sole. The use of LHRHa for the induction of gonadal maturation in English sole, however, was preferred, because generally 1) a higher percentage of the LHRHa-treated fish spawned compared to the CPE-treated fish, 2) the percent fertilization and percent normal larvae were similar to fish spawned immediately after capture for all the stages of gonadal development examined, and 3) dose could be better controlled. The present results also supported previous findings suggesting that females contribute most of the variability to fertilization success but the results did not support the observation that egg buoyancy was related to egg viability. RP SANBORN, HR (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,DIV ENVIRONM CONSERVAT,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. NR 0 TC 4 Z9 6 U1 0 U2 0 PU BLACKWELL WISSENSCHAFTS-VERLAG GMBH PI BERLIN PA KURFURSTENDAMM 57, D-10707 BERLIN, GERMANY SN 0175-8659 J9 J APPL ICHTHYOL JI J. Appl. Ichthyol.-Z. Angew. Ichthyol. PD MAR PY 1991 VL 7 IS 1 BP 15 EP 25 DI 10.1111/j.1439-0426.1991.tb00590.x PG 11 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA FG325 UT WOS:A1991FG32500003 ER PT J AU JONES, NP SHENTON, HW AF JONES, NP SHENTON, HW TI A MODIFIED, SLOWLY VARYING PARAMETER APPROACH FOR SYSTEMS WITH IMPULSIVE LOADINGS SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article AB Many oscillating systems in practice are subject to periodic, impulsive loads during their motion. For nonlinear systems traditional methods, such as the slowly varying parameter technique, have been used to study the response of such systems by "smearing" the effect of the impulse over one cycle of the oscillation. Unfortunately, in many instances this approach violates the basic assumption used in the application of the averaging technique, resulting in limited predictive capability. This paper presents a modification to the standard slowly varying parameter technique for nonlinear systems which addresses this problem by assuming a solution form which admits a discontinuity in velocity at the time the impulse is applied. Examples are given which outline the improvement in accuracy of the new technique. C1 JOHNS HOPKINS UNIV,DEPT CIVIL ENGN,BALTIMORE,MD 21218. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RI Jones, Nicholas/A-2328-2010 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 SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD MAR PY 1991 VL 58 IS 1 BP 251 EP 258 DI 10.1115/1.2897160 PG 8 WC Mechanics SC Mechanics GA HP715 UT WOS:A1991HP71500037 ER PT J AU BARNSTON, AG AF BARNSTON, AG TI AN EMPIRICAL-METHOD OF ESTIMATING RAIN-GAGE AND RADAR RAINFALL MEASUREMENT BIAS AND RESOLUTION SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID 2ND PHASE FACE-2; AREA; ACCURACY; GAUGE AB This paper presents new methods of estimating the bias and the resolution of radar and raingage area average rainfall measurements over a defined area when both devices are employed simultaneously. The bias of raingage measurements for various rainfall amount ranges is estimated from published data, and the bias for radar measurement is then determined through comparison with the raingage recordings. The resolution estimations are carried out using error variance analysis on corresponding sets of gage and radar observations. The assumptions underlying this technique demand a uniform terrain for rainfall measurements, a large sample of cases, and, for one of the analysis options, a high correlation between radar and gage rainfall measurements. The procedure is illustrated using the gage and radar rainfall data from the second phase of the Florida Area Cumulus Experiment (FACE-2). The gage sampling error variance estimations for various rainfall amount categories using an empirical radar-derived method are examined by comparison with those of published studies using alternate methods and are found to be in general agreement. The FACE-2 gage network is found to provide more highly resolved rainfall measurements than the WSR-57 radar in moderate or heavy rainfall, but the radar exhibits the superior resolution in light rainfall if the radar rainfall adjustment used in FACE is not carried out. The radar rainfall adjustment appears to reduce radar measurement bias quite effectively, but the resolution is generally not improved and is degraded in below-median rainfall amounts. RP BARNSTON, AG (reprint author), NOAA,NATL WEATHER SERV,NATL METEREOL CTR,CTR CLIMATE ANAL,W NMC51 WWB ROOM 604,WASHINGTON,DC 20233, USA. NR 20 TC 25 Z9 26 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD MAR PY 1991 VL 30 IS 3 BP 282 EP 296 DI 10.1175/1520-0450(1991)030<0282:AEMOER>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FJ114 UT WOS:A1991FJ11400002 ER PT J AU EPSTEIN, ES AF EPSTEIN, ES TI ON OBTAINING DAILY CLIMATOLOGICAL VALUES FROM MONTHLY MEANS SO JOURNAL OF CLIMATE LA English DT Note AB A method is proposed for deriving daily climatological values that are consistent with a given set of monthly means or monthly totals. It involves making an adjustment to a harmonic analysis of the monthly values. The method appears to provide reasonable results even under difficult circumstances. RP EPSTEIN, ES (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,CTR CLIMATE ANAL,5200 AUTH RD,WASHINGTON,DC 20233, USA. NR 0 TC 24 Z9 26 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD MAR PY 1991 VL 4 IS 3 BP 365 EP 368 DI 10.1175/1520-0442(1991)004<0365:OODCVF>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FG790 UT WOS:A1991FG79000006 ER PT J AU HEMSLEY, JM MCGEHEE, DD KUCHARSKI, WM AF HEMSLEY, JM MCGEHEE, DD KUCHARSKI, WM TI NEARSHORE OCEANOGRAPHIC MEASUREMENTS - HINTS ON HOW TO MAKE THEM SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE DATA COLLECTION; NON-DIRECTIONAL WAVES; DIRECTIONAL WAVES; CURRENTS; WATER LEVELS; WINDS AB Selection of instruments for coastal oceanographic measurements is difficult. Few people involved with coastal engineering have the experience to make informed decisions about which gage will work best under their particular circumstances. Consideration of a few general characteristics of gage types will help in the selection of the most appropriate gage for a data collection effort. RP HEMSLEY, JM (reprint author), NOAA,NATL DATA BUOY CTR,STENNIS SPACE CTR,MS 39529, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD SPR PY 1991 VL 7 IS 2 BP 301 EP 315 PG 15 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA FD868 UT WOS:A1991FD86800001 ER PT J AU NGUYEN, TN HUBBARD, JB MCFADDEN, GB AF NGUYEN, TN HUBBARD, JB MCFADDEN, GB TI A MATHEMATICAL-MODEL FOR THE CATHODIC BLISTERING OF ORGANIC COATINGS ON STEEL IMMERSED IN ELECTROLYTES SO JOURNAL OF COATINGS TECHNOLOGY LA English DT Article ID CORROSION; MECHANISM; INTERFACE; ADHESION; SURFACE; FILMS AB A physical/mathematical model which describes blistering resulting from the corrosion of coated metals containing defects exposed to electrolytes has been developed. The model is based on the two-dimensional diffusion of cations through some arbitrary medium. Cations migrating along the coating/metal interface from the defect to the cathodic sites are assumed to be responsible for the formation of highly water-soluble corrosion products, leading to blistering. Solutions of the model were expressed in terms of dimensionless parameters. Concentration profiles between the blister and defect and cation flux into the blister as functions of time, blister size, distance between the blister and defect, ion diffusivity, and potential gradient were calculated. The predictions were related to available experimental data in the literature on cation uptakes and blistering rates for coated steel panels exposed to metal chloride solutions. RP NGUYEN, TN (reprint author), US DEPT COMMERCE,NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI McFadden, Geoffrey/A-7920-2008 OI McFadden, Geoffrey/0000-0001-6723-2103 NR 38 TC 23 Z9 29 U1 2 U2 18 PU FEDERATION SOC COATING TECH PI BLUE BELL PA 492 NORRISTOWN ROAD, BLUE BELL, PA 19422 SN 0361-8773 J9 J COATING TECHNOL JI J. Coat. Technol. PD MAR PY 1991 VL 63 IS 794 BP 43 EP 52 PG 10 WC Chemistry, Applied; Materials Science, Coatings & Films SC Chemistry; Materials Science GA FB953 UT WOS:A1991FB95300006 ER PT J AU SVENSSON, LA DILL, J SJOLIN, L WLODAWER, A TONER, M BACON, D MOULT, J VEERAPANDIAN, B GILLILAND, GL AF SVENSSON, LA DILL, J SJOLIN, L WLODAWER, A TONER, M BACON, D MOULT, J VEERAPANDIAN, B GILLILAND, GL TI THE CRYSTAL PACKING INTERACTIONS OF 2 DIFFERENT CRYSTAL FORMS OF BOVINE RIBONUCLEASE-A SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID MACROMOLECULAR STRUCTURES; REFINEMENT; CRYSTALLIZATION; RESOLUTION AB The crystal packing interactions of two crystal forms of bovine Ribonuclease A are compared. One form, grown in 43% t-butanol at pH 5.3, has space group P2(1), one molecule in the asymmetric unit, a = 30.18 angstrom, b = 38.4 angstrom, c = 53.32 angstrom and beta = 105.85-degrees. The other crystal form is grown in 3M CsCl and acetate buffer at pH 5.1, has space group P2(1)2(1)2(1), two molecules in the asymmetric unit, a = 53.14 angstrom, b = 64.61 angstrom and c = 73.64 angstrom. An analysis of the crystal packing interactions, including solvent bridging, indicates that the high-alcohol crystal form of Ribonuclease A has a balance of hydrogen bonding, electrostatic and Van der Waals interactions. In contrast, the high-salt crystal packing forces are dominated by Van der Waals interactions, but at the dimer interface of the molecules in this crystal form the interactions have a large electrostatic component. The electrostatic interactions of the dimer may be due to a rearrangement in the charge-charge interactions at the active site, a direct result of the presence of the inhibitor, deoxythymidine, covalently bound to His 12. C1 UNIV MARYLAND,MARYLAND BIOTECHNOL INST,CTR ADV RES BIOTECHNOL,SHADY GROVE,9600 GUDELSKY DR,ROCKVILLE,MD 20850. NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899. CHALMERS UNIV TECHNOL,DEPT INORGAN CHEM,S-41296 GOTHENBURG,SWEDEN. NCI,FREDERICK CANC RES FACIL,CRYSTALLOG LAB,BRI,BASIC RES PROGRAM,FREDERICK,MD 21701. RI Sjolin, Lennart/B-2619-2010 NR 17 TC 14 Z9 14 U1 0 U2 0 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 MAR PY 1991 VL 110 IS 1-2 BP 119 EP 130 PG 12 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA FF694 UT WOS:A1991FF69400016 ER PT J AU TODD, P SIKDAR, SK WALKER, C KORSZUN, ZR AF TODD, P SIKDAR, SK WALKER, C KORSZUN, ZR TI APPLICATION OF OSMOTIC DEWATERING TO THE CONTROLLED CRYSTALLIZATION OF BIOLOGICAL MACROMOLECULES AND ORGANIC-COMPOUNDS SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID CRYSTAL-GROWTH; PROTEIN CRYSTALS; NUCLEATION AB Several methods of crystallization of biological macromolecules depend upon the transport of water through the vapor phase - a process that is sensitive to ambient conditions (temperature, relative humidity). Other methods depend on the transport of solute by diffusion or through a membrane. By regulating the solute concentration on the outside of a reverse-osmosis membrane it is possible to control the rate at which macromolecules and other solutes are concentrated inside a membrane-bound fluid. The effect of dewatering rate on lysozyme crystal quality and growth rate was assessed. A 3-fold increase in concentration over a 9 day period yielded tetragonal crystals 0.5 mm on a side with sharp edges and with ordering at least to 1.73 angstrom. Transparent crystals of triglycine sulfate were grown by osmotic dewatering; in this case crystal growth could be enhanced or reversed by manipulating the external solution. C1 UNIV WISCONSIN PARKSIDE,DIV SCI,KENOSHA,WI 53141. RP TODD, P (reprint author), NATL INST STAND & TECHNOL 58310,325 BROADWAY,BOULDER,CO 80303, USA. NR 37 TC 19 Z9 19 U1 0 U2 2 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 MAR PY 1991 VL 110 IS 1-2 BP 283 EP 292 DI 10.1016/0022-0248(91)90897-E PG 10 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA FF694 UT WOS:A1991FF69400039 ER PT J AU SJOLIN, L WLODAWER, A BERGQVIST, G HOLM, P LOTH, K MALMSTROM, H ZAAR, J SVENSSON, LA GILLILAND, GL AF SJOLIN, L WLODAWER, A BERGQVIST, G HOLM, P LOTH, K MALMSTROM, H ZAAR, J SVENSSON, LA GILLILAND, GL TI PROTEIN CRYSTAL-GROWTH OF RIBONUCLEASE-A AND PANCREATIC TRYPSIN-INHIBITOR ABOARD THE MASER-3 ROCKET SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID LEAST-SQUARES REFINEMENT; X-RAY REFINEMENT; JOINT NEUTRON; RESOLUTION; FORM AB The growth of bovine Ribonuclease A (RNase A) and bovine Pancreatic Trypsin Inhibitor crystals has been studied simultaneously aboard MASER 3, a sounding rocket, and in a ground reference unit. For crystallization to take place within the 7 min and 15 s of microgravity during the flight, both macro- and micro-seed techniques of supersaturated protein solutions were employed. It was found that the convection-free environment of the MASER 3 protein crystal growth apparatus produced more and larger crystals than the ground reference unit. The RNase A crystals grown in microgravity diffracted X-rays to 1.06 angstrom resolution, approximately 0.2 angstrom higher resolution than previously observed in terrestrially grown RNase A crystals. The refined structure based on these data contains new features not seen in the lower resolution structures. C1 UNIV MARYLAND,MARYLAND BIOTECHNOL INST,CTR ADV RES BIOTECHNOL,SHADY GROVE,9600 GUDELSKY DR,ROCKVILLE,MD 20878. CHALMERS UNIV TECHNOL,DEPT INORGAN CHEM,S-41296 GOTHENBURG,SWEDEN. NCI,FREDERICK CANC RES FACIL,CRYSTALLOG LAB,BRI,BASIC RES PROGRAM,FREDERICK,MD 21701. SWEDISH SPACE AGCY,S-17154 SOLNA,SWEDEN. NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899. RI Sjolin, Lennart/B-2619-2010 NR 13 TC 8 Z9 9 U1 0 U2 0 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 MAR PY 1991 VL 110 IS 1-2 BP 322 EP 332 DI 10.1016/0022-0248(91)90902-H PG 11 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA FF694 UT WOS:A1991FF69400044 ER PT J AU WEBB, RE JOHNSTON, AD AF WEBB, RE JOHNSTON, AD TI DENTIN-BONDING MOLAR EFFICIENCY USING N-PHENYLGLYCINE, N-PHENYL-BETA-ALANINE, OR N-METHYL-N-PHENYLGLYCINE SO JOURNAL OF DENTAL RESEARCH LA English DT Article ID HARD TOOTH TISSUES; ADHESIVE; SYSTEM AB Three structurally related substituted amino acids (N-compounds) were studied in a three-step dentin-bonding protocol. The first step of an acidic ferric oxalate solution and the third step of a surface-active comonomer were held constant throughout the study. In the second step, the amount of the N-compound-either N-phenylglycine (NPG), N-methyl-N-phenylglycine (NMNPG), or N-phenyl-beta-alanine (NPBA)-was varied in acetone from 0 mol/L through 5 x 10-1 mol/L in seven steps. At 1 x 10-3 mol/L for NPG and NMNPG, average bond strength values were 7.4 +/- 2.2 and 10.5 +/- 2.7 MPa. The highest bond strength value for NMNPG was at 1 x 10-2 mol/L, with 13.2 +/- 4.0 MPa. The highest value for NPG was at 1 x 10-1 mol/L, with a value of 11.8 +/- 2.5 MPa. The average bond strength for NPBA did not differ from zero across the entire range of concentrations. Molar efficiency was defined as the bond strength per mole of these applied N-compounds. For the two N-compounds that did provide adhesion to dentin, NPG and NMNPG, the average bond strengths rose, peaked, and fell as the amounts of applied N-compound were increased. The molar efficiency dropped off as the concentration of applied N-compound rose. The least operator-sensitive and most efficient N-compound, NMNPG, delivered a bond strength equivalent to that of NPG, with 10% of the applied NPG amount. C1 NATL INST STAND & TECHNOL,AMER DENT ASSOC,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899. RP WEBB, RE (reprint author), USN,SCH DENT,NNDC,BETHESDA,MD 20814, USA. FU NIDCR NIH HHS [DE05129, DE09322] NR 14 TC 9 Z9 9 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD MAR PY 1991 VL 70 IS 3 BP 211 EP 214 DI 10.1177/00220345910700031101 PG 4 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA FD585 UT WOS:A1991FD58500011 PM 1999561 ER PT J AU MANNESTO, G LOOMIS, JB AF MANNESTO, G LOOMIS, JB TI EVALUATION OF MAIL AND IN-PERSON CONTINGENT VALUE SURVEYS - RESULTS OF A STUDY OF RECREATIONAL BOATERS SO JOURNAL OF ENVIRONMENTAL MANAGEMENT LA English DT Article DE RECREATION; BOATING; CONTINGENT VALUE SURVEYS ID VALUATION C1 UNIV CALIF DAVIS, DIV ENVIRONM STUDIES, DAVIS, CA 95616 USA. NATL MARINE FISHERIES SERV, GLOUCESTER, MA 01930 USA. NR 19 TC 17 Z9 18 U1 3 U2 3 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0301-4797 EI 1095-8630 J9 J ENVIRON MANAGE JI J. Environ. Manage. PD MAR PY 1991 VL 32 IS 2 BP 177 EP 190 DI 10.1016/S0301-4797(05)80032-5 PG 14 WC Environmental Sciences SC Environmental Sciences & Ecology GA FC084 UT WOS:A1991FC08400006 ER PT J AU BABRAUSKAS, V HARRIS, RH BRAUN, E LEVIN, BC PAABO, M GANN, RG AF BABRAUSKAS, V HARRIS, RH BRAUN, E LEVIN, BC PAABO, M GANN, RG TI LARGE-SCALE VALIDATION OF BENCH-SCALE FIRE TOXICITY TESTS SO JOURNAL OF FIRE SCIENCES LA English DT Article DE FIRE TESTS; FIRE TOXICITY; HAZARD ASSESSMENT; POLY(VINYL CHLORIDE); RADIANT HEAT; RIGID POLYURETHANE FOAM; ROOM FIRE TESTS; TEST VALIDATION; WOOD MATERIALS ID COMBUSTION AB A sizable number of bench-scale fire toxicity tests have been proposed over the last two decades. To date, no test method has successfully passed through the standards bodies ISO, ASTM, or BSI. The reasons are varied, but a major concern has been that none of the methods were seen to adequately predict the behavior of real, large-scale building fires. Such validation efforts have been held back both due to a shortage of good quality data, and because agreement had not been reached on the criteria for successful validation. NIST has now completed a pilot project to address both of these issues. In this study, several criteria for validation have been put forth. An initial data set has been compared against these criteria, comprising 2 bench-scale methods, 3 test materials, and a single real-scale fire scenario. The project results indicate that the course being pursued is appropriate, and provide illustrative performance data for the two bench-scale methods. The present project was a pilot study; further validation data will have to come from additional test materials and additional real-scale fire scenarios being examined. As a result of these studies, a factor-of-3 agreement between bench-scale and real-scale results was established as both useful and practical. RP BABRAUSKAS, V (reprint author), NATL INST STAND & TECHNOL,CTR FIRE RES,BLDG 224,ROOM A345,GAITHERSBURG,MD 20899, USA. NR 14 TC 2 Z9 2 U1 1 U2 4 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0734-9041 J9 J FIRE SCI JI J. Fire Sci. PD MAR-APR PY 1991 VL 9 IS 2 BP 125 EP 148 DI 10.1177/073490419100900203 PG 24 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA GV596 UT WOS:A1991GV59600003 ER PT J AU TEWARY, VK HEYLIGER, PR CLARK, AV AF TEWARY, VK HEYLIGER, PR CLARK, AV TI THEORY OF CAPACITIVE PROBE METHOD FOR NONCONTACT CHARACTERIZATION OF DIELECTRIC-PROPERTIES OF MATERIALS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB The capacitive probe method for noncontact characterization and monitoring of dielectric materials is analyzed theoretically. An analytical method based upon the Hilbert transform technique and a numerical method using the finite element technique for calculating the potential distribution and change in admittance of the probe caused by presence of the dielectric material as a function of liftoff (distance between the probe plane and the surface of the dielectric material) are described. The two methods are compared with each other and their relative advantages discussed. The possibility of extracting useful information about the dielectric constant of the material from experimental data is also discussed in the light of the proposed theory. RP TEWARY, VK (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303, USA. NR 5 TC 3 Z9 3 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD MAR PY 1991 VL 6 IS 3 BP 629 EP 638 DI 10.1557/JMR.1991.0629 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA FA769 UT WOS:A1991FA76900025 ER PT J AU ZHOU, SJ THOMSON, R AF ZHOU, SJ THOMSON, R TI DISLOCATION EMISSION AT LEDGES ON CRACKS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID BRITTLE DUCTILE TRANSITION; SINGLE-CRYSTALS; TIP DEFORMATION; SILICON; FRACTURE; CLEAVAGE; MODEL AB In this paper, we propose that, depending on their height, ledges on cracks can be efficient sources of dislocations at loadings well below the critical loading for homogeneous emission. Detailed 3-D elastic calculations are presented supporting this proposition. There are two configurations for emission: one which blunts the crack, and one we call a jogging configuration. By our calculations, the blunting configuration should be the more efficient source; however, jogging dislocations are more frequently observed, experimentally. We find that the ledge is only a finite source of dislocations, in the sense that the ledge height decreases as the dislocations are emitted. The atomic configuration at the ledge is composed of finite lengths of real dislocations, which is the reason why such dislocations can be emitted easier than homogeneously produced dislocations. The stresses at the ledge tip produce a cloud of bound dislocations near the ledge, pinned at the ledge ends, so that the ledge crack configuration becomes delocalized. Delocalization of the pileup dislocations in the jogging direction may explain why the jogging dislocations are more frequently seen. Implications for dislocation free zones and ductile transitions are discussed. RP ZHOU, SJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 28 TC 40 Z9 40 U1 1 U2 3 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD MAR PY 1991 VL 6 IS 3 BP 639 EP 653 DI 10.1557/JMR.1991.0639 PG 15 WC Materials Science, Multidisciplinary SC Materials Science GA FA769 UT WOS:A1991FA76900026 ER PT J AU MUNDER, A CHRISTENSEN, RG WISE, SA AF MUNDER, A CHRISTENSEN, RG WISE, SA TI MICROANALYSIS OF EXPLOSIVES AND PROPELLANTS BY ONLINE SUPERCRITICAL FLUID EXTRACTION CHROMATOGRAPHY WITH TRIPLE DETECTION SO JOURNAL OF MICROCOLUMN SEPARATIONS LA English DT Article DE SUPERCRITICAL FLUID CHROMATOGRAPHY; SUPERCRITICAL FLUID EXTRACTION; EXPLOSIVES; PROPELLANTS; ELECTRON CAPTURE DETECTOR; MICROANALYSIS; ONLINE ANALYSIS AB A compact analytical instrument is described which allows microsamples to be extracted with supercritical fluids, and the extract preconcentrated and analyzed by capillary supercritical fluid chromatography in a single coupled unit. Thus, no off-line sample pretreatment is required, and the possibility of extraneous contamination is reduced. To achieve greater selectivity and sensitivity for selected species, three different detectors (UV absorption, flame ionization and electron capture) were all connected on-line. This analytical instrument configuration was established by upgrading a commercial capillary supercritical fluid chromatograph using regular chromatographic supplies. To illustrate the analytical utility of this hyphenated technique, an assortment of compounds that are not easily determined by traditional gas chromatographic or liquid chromatographic methods was selected: explosives, propellants, and related species. The instrumental design, as well as selected analytical conditions (sample pretreatment,extraction, preconcentration, separation, and detection) were investigated to improve selectivity and/or sensitivity. The determination of explosive residues on soil is described as an environmental analysis application of the system. Detection limits for some compounds are estimated to be as low as 100 pg. The firearm propellants were characterized through their extractable organic constituents, and the usefulness of such characterization in forensic investigations is discussed. Closely related to this issue is the analysis of the residue in expended cartridge cases. A chromatographic fingerprint was obtained from the propellant used in the ammunition. This fingerprint can be used under certain circumstances to correlate a specific batch of propellant with the residue left in a fired cartridge case. C1 NATL INST STAND & TECHNOL,DIV ORGAN ANALYT RES,GAITHERSBURG,MD 20899. NR 0 TC 23 Z9 24 U1 1 U2 3 PU MICROSEPARATIONS INC PI PROVO PA DEPT CHEM BRIGHAM YOUNG UNIV, PROVO, UT 84602-1022 SN 1040-7685 J9 J MICROCOLUMN SEP JI J. Microcolumn Sep. PD MAR-APR PY 1991 VL 3 IS 2 BP 127 EP 140 DI 10.1002/mcs.1220030206 PG 14 WC Chemistry, Analytical SC Chemistry GA FP620 UT WOS:A1991FP62000004 ER PT J AU HOUGEN, JT MEERTS, WL OZIER, I AF HOUGEN, JT MEERTS, WL OZIER, I TI THE USE OF EXTENDED PERMUTATION-INVERSION GROUPS IN CONSTRUCTING HYPERFINE HAMILTONIANS FOR SYMMETRICAL-TOP INTERNAL ROTOR MOLECULES LIKE H3C-SIH3 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID PHOSPHORYL FLUORIDE OPF3; MICROWAVE-SPECTRUM; BEAM SPECTROSCOPY; ROTATIONAL SPECTRA; METHYL SILANE; TRANSITIONS; CH3CD3 C1 CATHOLIC UNIV NIJMEGEN,FYS LAB,6525 ED NIJMEGEN,NETHERLANDS. UNIV BRITISH COLUMBIA,DEPT PHYS,VANCOUVER V6T 2A6,BC,CANADA. RP HOUGEN, JT (reprint author), NATL INST STAND & TECHNOL,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. RI Meerts, W. Leo/B-6172-2008 OI Meerts, W. Leo/0000-0001-6457-3797 NR 34 TC 15 Z9 15 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD MAR PY 1991 VL 146 IS 1 BP 8 EP 48 DI 10.1016/0022-2852(91)90368-K PG 41 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA EZ162 UT WOS:A1991EZ16200002 ER PT J AU MIGDALL, AL WINNEWISSER, C AF MIGDALL, AL WINNEWISSER, C TI LINEARITY OF A SILICON PHOTODIODE AT 30 MHZ AND ITS EFFECT ON HETERODYNE MEASUREMENTS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE HETERODYNE; HIGH FREQUENCY; IRRADIANCE; LINEARITY; PHOTODIODE; SATURATION ID RANGE AB The effect of optical irradiance on the linearity of a Si photodiode was studied. These results are compared for light modulated at 30 MHz and at dc as the optical irradiance was varied over a 9 decade range. We discuss how these results affect the use of this detector as a heterodyne receiver. As the optical irradiance varied from 10(-2) to 10(+3) mW/cm2, while maintaining constant total power, the photocurrent was constant to about 1%, but as the power density increased further, the photocurrent increased about 13%. At the highest densities that we could achieve, about 6 x 10(7) mW/cm2, there was only slight evidence of the onset of saturation. These results are of importance in our work to use optical heterodyne detection to measure filter transmittances over a wide dynamic range. The results provide guidelines for achieving maximum accuracy when using this particular diode as an optical heterodyne receiver. RP MIGDALL, AL (reprint author), NATL INST STAND & TECHNOL, DIV RADIOMET PHYS, GAITHERSBURG, MD 20899 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1991 VL 96 IS 2 BP 143 EP 146 DI 10.6028/jres.096.005 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FM547 UT WOS:A1991FM54700001 PM 28184106 ER PT J AU KINNEY, PD PUI, DYH MULHOLLAND, GW BRYNER, NP AF KINNEY, PD PUI, DYH MULHOLLAND, GW BRYNER, NP TI USE OF THE ELECTROSTATIC CLASSIFICATION METHOD TO SIZE 0.1 MU-M SRM PARTICLES - A FEASIBILITY STUDY SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE AEROSOL GENERATOR; ATOMIZERS; CONDENSATION NUCLEI COUNTERS; ELECTRICAL MOBILITY; PARTICLE SIZE; POLYSTYRENE LATEX SPHERES ID DIFFERENTIAL MOBILITY ANALYZER; AEROSOLS AB The use of the electrostatic classification method for sizing monodisperse 0.1-mu-m polystyrene latex (PSL) spheres has been investigated experimentally. The objective was to determine the feasibility of using electrostatic classification as a standard method of particle sizing in the development of a 0.1-mu-m particle diameter Standard Reference Material (SRM). The mean particle diameter was calculated from a measurement of the mean electrical mobility of the PSL spheres as an aerosol using an electrostatic classifier. The performance of the classifier was investigated by measuring its transfer function, conducting a sensitivity analysis to verify the governing theoretical relationships, measuring the repeatability of particle sizing, and sizing NIST SRM 1691, 0.269-mu-m and NIST SRM 1690, 0.895-mu-m particles. Investigations of the aerosol generator's performance focused on the effect of impurities in the particle-suspending liquid on the resulting particle diameter. The uncertainty in particle diameter determined by electrical mobility measurements is found to be -3.3% to +3.0%. The major sources of uncertainty include the flow measurement, the slip correction, and a dependence of particle size on the aerosol flow rate. It was found that the classifier could be calibrated to indicate the correct size to within 0.1% for both SRM particle sizes if the defined classification length is decreased by 1.9%. C1 NATL INST STAND & TECHNOL, DIV FIRE MEASUREMENT & RES, GAITHERSBURG, MD 20899 USA. UNIV MINNESOTA, MINNEAPOLIS, MN 55455 USA. NR 21 TC 100 Z9 100 U1 0 U2 6 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1991 VL 96 IS 2 BP 147 EP 176 DI 10.6028/jres.096.006 PG 30 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FM547 UT WOS:A1991FM54700002 PM 28184107 ER PT J AU VERDIER, PH AF VERDIER, PH TI A MULTIPLE VARIABLE-ANGLE LIGHT-SCATTERING DETECTOR FOR GEL-PERMEATION CHROMATOGRAPHY SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE BRANCHED POLYMERS; CHAIN BRANCHING; GEL PERMEATION CHROMATOGRAPHY; LIGHT SCATTERING; POLYMER CHAIN BRANCHING; POLYMER MOLECULAR WEIGHT; SIZE EXCLUSION CHROMATOGRAPHY; STAR POLYMERS; STAR-BRANCHED POLYMERS ID COMBINED EXCLUSION CHROMATOGRAPHY; MOLECULAR-WEIGHT DETECTION; POLYSTYRENES; PHOTOMETRY AB A light scattering detector has been designed and constructed for use with gel permeation chromatographs. The detector measures light scattered from the eluting sample simultaneously at nine scattering angles, and is connected to a computer-controlled display which exhibits the angular dependence of the scattering in real time while the sample is eluting. Use of the light-scattering detector in conjunction with the usual concentration-sensitive detector allows the direct determination of molecular weight as a function of elution volume, thereby making the chromatographic system "self-calibrating." Tests of the system with a series of linear and branched polystyrenes suggest that it will be a useful tool for the study and characterization of branched polymers. RP VERDIER, PH (reprint author), NATL INST STAND & TECHNOL, DIV POLYMERS, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 19 TC 0 Z9 0 U1 1 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1991 VL 96 IS 2 BP 177 EP 189 DI 10.6028/jres.096.007 PG 13 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FM547 UT WOS:A1991FM54700003 PM 28184108 ER PT J AU WU, YC KOCH, WF PRATT, KW AF WU, YC KOCH, WF PRATT, KW TI PROPOSED NEW ELECTROLYTIC CONDUCTIVITY PRIMARY STANDARDS FOR KCL SOLUTIONS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE CELL CONSTANT; CONDUCTANCE; DEMAL; ELECTROLYTIC CONDUCTIVITY; MOLAL; POTASSIUM CHLORIDE; PRIMARY STANDARDS; RESISTANCE; SPECIFIC CONDUCTANCE ID CONDUCTANCE AB An absolute determination of aqueous electrolytic conductivity has been made for 0.01 molal (m) and 0.1 m potassium chloride solutions, over the temperature range of 0 to 50-degrees-C in 5 degree intervals. A cell with a removable center section of accurately known length and area was used for the measurements. Values were adjusted to be in conformity with the ITS-90 temperature scale. The overall uncertainty over the entire temperature range is estimated to be 0.03%. Values at 25-degrees-C for 0.01 and 0.1 m are 0.00140823 and 0.0128246 S/cm, respectively. It is proposed that these values be adopted as primary standards for aqueous electrolytic conductivity, replacing the demal scale. RP WU, YC (reprint author), NATL INST STAND & TECHNOL, DIV INORGAN ANALYT RES, ELECTROANALYT RES GRP, GAITHERSBURG, MD 20899 USA. NR 13 TC 45 Z9 47 U1 1 U2 11 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1991 VL 96 IS 2 BP 191 EP 201 DI 10.6028/jres.096.008 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FM547 UT WOS:A1991FM54700004 PM 28184109 ER PT J AU CHOW, LC TAKAGI, S TUNG, W JORDAN, TH AF CHOW, LC TAKAGI, S TUNG, W JORDAN, TH TI DIGITAL IMAGE-ANALYSIS ASSISTED MICRORADIOGRAPHY - MEASUREMENT OF MINERAL-CONTENT OF CARIES LESIONS IN TEETH SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE DEMINERALIZATION; DENTAL CARIES; DIGITAL IMAGE ANALYSIS; MICRORADIOGRAPHY; REMINERALIZATION; TOOTH MINERAL ID ENAMEL AB This study investigated the feasibility of using a digital image analysis system to process the information contained in microradiographs of tooth sections that included dental caries lesions. The results show that by using an aluminum step wedge to provide a range of thickness standards and a sound area of the sample as an internal reference, data on tooth mineral content as a function of the location can be obtained with an estimated error of less than 5% relative to the mineral content of sound area. This microradiographic technique allows the response of tooth samples to a remineralization treatment to be quantitatively measured and statistically analyzed. RP CHOW, LC (reprint author), NATL INST STAND & TECHNOL, AMER DENT ASSOC HLTH FDN, PAFFENBARGER RES CTR, GAITHERSBURG, MD 20899 USA. NR 12 TC 19 Z9 19 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1991 VL 96 IS 2 BP 203 EP 214 DI 10.6028/jres.096.009 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FM547 UT WOS:A1991FM54700005 PM 28184110 ER PT J AU ASMAIL, C AF ASMAIL, C TI BIDIRECTIONAL SCATTERING DISTRIBUTION FUNCTION (BSDF) - A SYSTEMATIZED BIBLIOGRAPHY SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Review DE BIDIRECTIONAL REFLECTANCE DISTRIBUTION FUNCTION (BRDF); BIDIRECTIONAL SCATTERING DISTRIBUTION FUNCTION (BSDF); BIDIRECTIONAL TRANSMITTANCE DISTRIBUTION FUNCTION (BTDF); COHERENCE; DIFFUSE REFLECTANCE; INSTRUMENT SIGNATURE; INVERSE SCATTERING PROBLEM; POLARIZATION; SCATTERING THEORY; SPECULAR REFLECTANCE; STRAY LIGHT; SURFACE FINISH ID POLARIZED-LIGHT-SCATTERING; OPTICAL-SURFACES; STATISTICAL PROPERTIES; MATRIX-ELEMENTS; ROUGH SURFACES; ANGLE SCATTER; PERFORMANCE; MICROSTRUCTURE; TRANSMISSION; ABERRATIONS AB In conjunction with the development of a bidirectional scattering metrology project, a large number of papers pertaining to the theory and measurement of bidirectional scattering from optical surfaces were collected and categorized. This collection includes papers that deal with various aspects of the bidirectional scattering distribution function (BSDF), its measurement, interpretation, use, and implications. Each paper is classified in one or more subject categories on the basis of its technical content. The subject categories are included just to serve as a key to the most salient characteristics of each paper cited. Because of the interest in this field, this bibliography is being published as a service to the public. RP ASMAIL, C (reprint author), NATL INST STAND & TECHNOL, DIV RADIOMET PHYS, GAITHERSBURG, MD 20899 USA. NR 164 TC 11 Z9 11 U1 2 U2 10 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1991 VL 96 IS 2 BP 215 EP 223 DI 10.6028/jres.096.010 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FM547 UT WOS:A1991FM54700006 PM 28184111 ER PT J AU GALLAWA, RL GARDNER, JL NETTLETON, DH STOCK, KD WARD, TH LI, XY AF GALLAWA, RL GARDNER, JL NETTLETON, DH STOCK, KD WARD, TH LI, XY TI A LIMITED INTERNATIONAL INTERCOMPARISON OF RESPONSIVITY SCALES AT FIBER OPTIC WAVELENGTHS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE GERMANIUM DETECTORS; INTERNATIONAL INTERCOMPARISON; NATIONAL STANDARDS; OPTICAL COMMUNICATIONS; OPTICAL DETECTORS; OPTICAL POWER; RESPONSIVITY AB We report here on a recent limited international intercomparison of responsivity scales at wavelengths of interest to the optical communications community. Participants in the comparison were the national laboratories in the United States, the United Kingdom, Germany, and Australia. The wavelengths tested were 1300 and 1550 nm. Data taken at 850 nm are only briefly discussed. The disagreement between the national laboratories' responsivity scale is comfortably within the uncertainty claimed by each laboratory. C1 CSIRO, NATL MEASUREMENT LAB, DIV APPL PHYS, LINDFIELD, NSW 2070, AUSTRALIA. NATL PHYS LAB, DIV QUANTUM METROL, FIBRE OPT SECT, TEDDINGTON TW11 0LW, MIDDX, ENGLAND. PHYS TECH BUNDESANSTALT, RADIOMETRY SECT, W-3300 BRAUNSCHWEIG, GERMANY. RP GALLAWA, RL (reprint author), NATL INST STAND & TECHNOL, DIV ELECTROMAGNET TECHNOL, BOULDER, CO 80303 USA. NR 15 TC 1 Z9 1 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1991 VL 96 IS 2 BP 225 EP 230 DI 10.6028/jres.096.011 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FM547 UT WOS:A1991FM54700007 PM 28184112 ER PT J AU DAY, GW FRANZEN, DL AF DAY, GW FRANZEN, DL TI 6TH BIENNIAL SYMPOSIUM ON OPTICAL FIBER MEASUREMENTS SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Note RP DAY, GW (reprint author), NATL INST STAND & TECHNOL, DIV ELECTROMAGNET TECHNOL, BOULDER, CO 80303 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD MAR-APR PY 1991 VL 96 IS 2 BP 231 EP 232 DI 10.6028/jres.096.012 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA FM547 UT WOS:A1991FM54700008 PM 28184113 ER PT J AU STRATY, GC HANLEY, HJM GLINKA, CJ AF STRATY, GC HANLEY, HJM GLINKA, CJ TI SHEARING APPARATUS FOR NEUTRON-SCATTERING STUDIES ON FLUIDS - PRELIMINARY-RESULTS FOR COLLOIDAL SUSPENSIONS SO JOURNAL OF STATISTICAL PHYSICS LA English DT Article DE COLLOIDAL SUSPENSION; COUETTE FLOW; NEUTRON SCATTERING; SANS; SHEAR-INDUCED MELTING; SHEARING CELL ID FLOW AB A Couette-type concentric cylinder apparatus to investigate liquids at equilibrium and under shear has been constructed and tested. The apparatus is designed for a neutron facility and is optimized as a general purpose adjunct to the small-angle neutron scattering (SANS) equipment. It is versatile and rugged; a wide range of shear rates and operating temperatures can be covered; and controls are fully automated. Test results with sheared colloidal suspensions of 91-nm polystyrene spheres are presented. Evidence of shear-induced structure changes is clear. C1 NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. RP STRATY, GC (reprint author), NIST,DIV THERMOPHYS,BOULDER,CO 80303, USA. NR 17 TC 34 Z9 35 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-4715 J9 J STAT PHYS JI J. Stat. Phys. PD MAR PY 1991 VL 62 IS 5-6 BP 1015 EP 1023 DI 10.1007/BF01128174 PG 9 WC Physics, Mathematical SC Physics GA FE896 UT WOS:A1991FE89600009 ER PT J AU BOWEN, RL EICHMILLER, FC MARJENHOFF, WA AF BOWEN, RL EICHMILLER, FC MARJENHOFF, WA TI GLASS-CERAMIC INSERTS ANTICIPATED FOR MEGAFILLED COMPOSITE RESTORATIONS - RESEARCH MOVES INTO THE OFFICE SO JOURNAL OF THE AMERICAN DENTAL ASSOCIATION LA English DT Article ID POROUS REINFORCING FILLERS; RESINS C1 NATL INST STAND & TECHNOL,PAFFENBARGER RES CTR,AMER DENT ASSOC HLTH FDN,GAITHERSBURG,MD 20899. NATL INST STAND & TECHNOL,PAFFENBARGER RES CTR,GAITHERSBURG,MD. NR 16 TC 20 Z9 20 U1 0 U2 0 PU AMER DENTAL ASSN PI CHICAGO PA 211 E CHICAGO AVE, CHICAGO, IL 60611 SN 0002-8177 J9 J AM DENT ASSOC JI J. Am. Dent. Assoc. PD MAR PY 1991 VL 122 IS 3 BP 71 EP & PG 0 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA FB477 UT WOS:A1991FB47700017 PM 1826914 ER PT J AU BINSTOCK, DA GROHSE, PM GASKILL, A SELLERS, C KINGSTON, HM JASSIE, LB AF BINSTOCK, DA GROHSE, PM GASKILL, A SELLERS, C KINGSTON, HM JASSIE, LB TI DEVELOPMENT AND VALIDATION OF A METHOD FOR DETERMINING ELEMENTS IN SOLID-WASTE USING MICROWAVE DIGESTION SO JOURNAL OF THE ASSOCIATION OF OFFICIAL ANALYTICAL CHEMISTS LA English DT Article ID ATOMIC-ABSORPTION SPECTROMETRY; BIOLOGICAL SAMPLES; RAPID-DETERMINATION; FLOW-INJECTION; ACID DIGESTION; TRACE-METALS; OVEN; DISSOLUTION; ZINC; DECOMPOSITION AB A microwave-assisted method for preparing samples for determination of elements in solid waste has been developed (draft EPA Method 3051). Validation of the sample preparation method was performed through a collaborative study to determine its precision and accuracy. Fifteen independent laboratories digested 4 National Institute of Standards and Technology (NIST) standard reference materials (SRMs) and 1 solvent recovery waste in duplicate. Digestates were analyzed for 19 elements using inductively coupled plasma (ICP) emission spectroscopy. The precision and bias of the method were evaluated. When compared with an open vessel hot-plate digestion method (SW-846 Method 3050), the microwave method produced similar analytical results with better overall precision. Bias for the 1 sample that allowed this determination was found to be excellent. C1 US EPA,OFF SOLID WASTE,WASHINGTON,DC 20460. NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. RP BINSTOCK, DA (reprint author), RES TRIANGLE INST,RES TRIANGLE PK,NC 27709, USA. NR 30 TC 33 Z9 33 U1 0 U2 1 PU AOAC INTERNATIONAL PI GAITHERSBURG PA 481 NORTH FREDRICK AVE, STE 500, GAITHERSBURG, MD 20877-2504 SN 0004-5756 J9 J ASSOC OFF ANA CHEM PD MAR-APR PY 1991 VL 74 IS 2 BP 360 EP 366 PG 7 WC Chemistry, Analytical SC Chemistry GA FD110 UT WOS:A1991FD11000017 ER PT J AU RANDEL, WJ HELD, IM AF RANDEL, WJ HELD, IM TI PHASE SPEED SPECTRA OF TRANSIENT EDDY FLUXES AND CRITICAL LAYER ABSORPTION SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID BAROCLINIC INSTABILITY; GENERAL-CIRCULATION; SOUTHERN-HEMISPHERE; BAROTROPIC DECAY; WAVES; MODEL; TROPOSPHERE; EDDIES AB Tropospheric zonal mean eddy fluxes of heat and momentum, and the divergence of the Eliassen-Palm flux, are decomposed into contributions from different zonal phase speeds. Data analyzed are ECMWF operational global analyses covering 1980-87. Eastward moving medium-scale waves (zonal waves 4-7) dominate the spectra of lower tropospheric heat fluxes in both hemispheres and all seasons. Upper tropospheric wave flux spectra are similar to the low level spectra in midlatitudes, but shift to slower zonal phase speeds as low latitudes are approached. The cause of this shift is the selective absorption of faster moving components in midlatitudes as the waves propagate meridionally. Latitude-phase speed distributions of eddy fluxes are constructed and compared to the zonal mean wind structure. These results demonstrate that upper tropospheric eddies break and decelerate the zonal mean flow approximately 10-degrees-20-degrees in latitude away from their critical line (where phase speed equals zonal wind speed). Comparisons are also made with results from the middle stratosphere. C1 NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ. RP RANDEL, WJ (reprint author), NATL CTR ATMOSPHER RES,DIV CLIMATE & GLOBAL DYNAM,POB 3000,BOULDER,CO 80307, USA. RI Randel, William/K-3267-2016 OI Randel, William/0000-0002-5999-7162 NR 25 TC 152 Z9 152 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR 1 PY 1991 VL 48 IS 5 BP 688 EP 697 DI 10.1175/1520-0469(1991)048<0688:PSSOTE>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FC931 UT WOS:A1991FC93100002 ER PT J AU READER, J ACQUISTA, N KAUFMAN, V AF READER, J ACQUISTA, N KAUFMAN, V TI SPECTRUM AND ENERGY-LEVELS OF 7-TIMES-IONIZED KRYPTON (KR-VIII) AND RESONANCE LINES OF 8-TIMES-IONIZED KRYPTON (KR-IX) SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID COPPER-LIKE IONS; BR-VII; AS-V; ISOELECTRONIC SEQUENCE; VACUUM ULTRAVIOLET; EXTENDED ANALYSIS; BEAM-FOIL; MO-XIII; SE-VI; TRANSITIONS AB The spectrum of the copperlike ion Kr VIII was observed with a low-inductance spark and 10.7-m normal- and grazing-incidence spectrographs. A total of 46 new lines with wavelengths ranging from 115 to 696 angstrom were identified: 18 of the type 3d10nl-3d10nl', 10 of the type 3d10(4)s-3d9(4)s4p, and 18 of the type 3d10(4)p-3d9(4)p2. From these lines 37 new energy levels were determined: 14 of the type 3d10nl, 10 belonging to 3d9(4)s4p, and 13 to 3d9(4)p2. New values for all known levels were derived by combining the present results with measurements at longer wavelength by Gallardo et al. [Appl. Opt. 28, 5088 (1989)]. The ionization energy was found to be 1014 665 +/- 25 cm-1 (125.802 +/- 0.003 eV). New wavelength measurements were made for the 3d10-3d9(4)p,4f resonance lines of the nickellike ion Kr IX. RP READER, J (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 40 TC 19 Z9 19 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD MAR PY 1991 VL 8 IS 3 BP 538 EP 547 DI 10.1364/JOSAB.8.000538 PG 10 WC Optics SC Optics GA FA751 UT WOS:A1991FA75100007 ER PT J AU FIRST, PN STROSCIO, JA PIERCE, DT DRAGOSET, RA CELOTTA, RJ AF FIRST, PN STROSCIO, JA PIERCE, DT DRAGOSET, RA CELOTTA, RJ TI A SYSTEM FOR THE STUDY OF MAGNETIC-MATERIALS AND MAGNETIC IMAGING WITH THE SCANNING TUNNELING MICROSCOPE SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 5TH INTERNATIONAL CONF ON SCANNING TUNNELING MICROSCOPY/SPECTROSCOPY ( STM 90 ) / 1ST INTERNATIONAL CONF ON NANOMETER SCALE SCIENCE AND TECHNOLOGY ( NANO 1 ) CY JUL 23-27, 1990 CL BALTIMORE, MD SP AMER VACUUM SOC, USN, OFF NAVAL RES, USAF, OFF SCI RES, NATL SCI FDN, JOHN HOPKINS UNIV, APPL PHYS LAB ID SPIN POLARIZATION ANALYZER; SECONDARY ELECTRONS; EMISSION; SURFACE AB A report of work in progress to determine the feasibility of imaging the magnetization of ferromagnetic samples with the scanning tunneling microscope (STM) is presented. A vacuum system was designed to test several different proposals as well as to prepare and characterize thin films of magnetic materials by conventional means, including STM. This was begun with an attempt to detect spatially resolved spin-polarization of secondary electrons emitted from the sample when operating the STM in the scanning field emission mode. Results are currently inconclusive, but encouraging. A weak spin-polarization signal has been observed corresponding to one of the in-plane components of magnetization. However, topographic feedthrough has not been fully eliminated as a possible spurious source of contrast. RP FIRST, PN (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 19 TC 10 Z9 10 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAR-APR PY 1991 VL 9 IS 2 BP 531 EP 536 DI 10.1116/1.585562 PN 2 PG 6 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA FL004 UT WOS:A1991FL00400026 ER PT J AU WHITMAN, LJ STROSCIO, JA DRAGOSET, RA CELOTTA, RJ AF WHITMAN, LJ STROSCIO, JA DRAGOSET, RA CELOTTA, RJ TI A SCANNING TUNNELING MICROSCOPY STUDY OF CLEAN AND CS-COVERED INSB(110) SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 5TH INTERNATIONAL CONF ON SCANNING TUNNELING MICROSCOPY/SPECTROSCOPY ( STM 90 ) / 1ST INTERNATIONAL CONF ON NANOMETER SCALE SCIENCE AND TECHNOLOGY ( NANO 1 ) CY JUL 23-27, 1990 CL BALTIMORE, MD SP AMER VACUUM SOC, USN, OFF NAVAL RES, USAF, OFF SCI RES, NATL SCI FDN, JOHN HOPKINS UNIV, APPL PHYS LAB ID ENERGY-LOSS-SPECTROSCOPY; SEMICONDUCTOR INTERFACES; GAAS(110); SURFACES; DIFFRACTION; GEOMETRY AB Scanning tunneling microscopy has been employed to study clean and Cs-covered InSb(110) surfaces. Atomic-resolution images of both the filled and empty electronic state densities have been obtained. The surface relaxation determined from these images is in good agreement with that predicted by structure calculations. A variety of surface defects have been observed, with the most common appearing to be simple Sb vacancies. Adjacent In and Sb vacancies (Schottky defects) have also been observed. The perturbation of the surface surrounding these defects is asymmetrical along [001], as might be expected due to the asymmetry in the surface. Surprisingly, the perturbation is also asymmetrical along [11BAR0], where symmetry is expected. Cs adsorbed on room-temperature InSb(110) forms one-dimensional zig-zag chains along [11BAR0], similar to those previously observed on GaAs(110). RP WHITMAN, LJ (reprint author), NATL INST STAND & TECHNOL,DIV ELECTRON & OPT PHYS,GAITHERSBURG,MD 20899, USA. RI Whitman, Lloyd/G-9320-2011 OI Whitman, Lloyd/0000-0002-3117-1174 NR 29 TC 35 Z9 35 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAR-APR PY 1991 VL 9 IS 2 BP 770 EP 774 DI 10.1116/1.585508 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA FL004 UT WOS:A1991FL00400082 ER PT J AU DAGATA, JA SCHNEIR, J HARARY, HH BENNETT, J TSENG, W AF DAGATA, JA SCHNEIR, J HARARY, HH BENNETT, J TSENG, W TI PATTERN GENERATION ON SEMICONDUCTOR SURFACES BY A SCANNING TUNNELING MICROSCOPE OPERATING IN AIR SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 5TH INTERNATIONAL CONF ON SCANNING TUNNELING MICROSCOPY/SPECTROSCOPY ( STM 90 ) / 1ST INTERNATIONAL CONF ON NANOMETER SCALE SCIENCE AND TECHNOLOGY ( NANO 1 ) CY JUL 23-27, 1990 CL BALTIMORE, MD SP AMER VACUUM SOC, USN, OFF NAVAL RES, USAF, OFF SCI RES, NATL SCI FDN, JOHN HOPKINS UNIV, APPL PHYS LAB ID METALLIC FEATURES; SILICON; PASSIVATION; SI; LITHOGRAPHY; SULFUR; GAAS AB Recent results employing scanning tunneling microscope-based techniques for the generation of nanometer-scale patterns on passivated semiconductor surfaces are presented. Preparation and characterization of hydrogen-passivated silicon and sulfur-passivated gallium arsenide surfaces are described and the determination of the chemical and morphological properties of the patterned regions by scanning electron microscopy and time-of-flight secondary ion mass spectrometry are discussed. Our recent demonstration that ultrashallow, oxide features written by scanning tunneling microscope (STM) can serve as an effective mask for selective-area GaAs heteroepitaxy on silicon is used to illustrate key requirements necessary for the realization of a unique, STM-based nanotechnology. C1 NATL INST STAND & TECHNOL,DIV GAS & PARTICULATE SCI,GAITHERSBURG,MD 20899. NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899. RP DAGATA, JA (reprint author), NATL INST STAND & TECHNOL,DIV PRECIS ENGN,GAITHERSBURG,MD 20899, USA. RI Schaff, William/B-5839-2009 NR 28 TC 79 Z9 80 U1 0 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAR-APR PY 1991 VL 9 IS 2 BP 1384 EP 1388 DI 10.1116/1.585202 PN 2 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA FL004 UT WOS:A1991FL00400214 ER PT J AU AHRENS, JP AF AHRENS, JP TI STABILITY OF REEF BREAKWATERS - DISCUSSION SO JOURNAL OF WATERWAY PORT COASTAL AND OCEAN ENGINEERING-ASCE LA English DT Discussion RP AHRENS, JP (reprint author), NOAA,SEA GRANT,1335 EW HWY,SILVER SPRING,MD 20910, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-950X J9 J WATERW PORT C-ASCE JI J. Waterw. Port Coast. Ocean Eng.-ASCE PD MAR-APR PY 1991 VL 117 IS 2 BP 190 EP 194 DI 10.1061/(ASCE)0733-950X(1991)117:2(190.2) PG 5 WC Engineering, Civil; Engineering, Ocean; Water Resources SC Engineering; Water Resources GA EZ160 UT WOS:A1991EZ16000009 ER PT J AU FAHNENSTIEL, GL CARRICK, HJ ITURRIAGA, R AF FAHNENSTIEL, GL CARRICK, HJ ITURRIAGA, R TI PHYSIOLOGICAL-CHARACTERISTICS AND FOOD-WEB DYNAMICS OF SYNECHOCOCCUS IN LAKES HURON AND MICHIGAN SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID NORTHWEST ATLANTIC-OCEAN; 3 WATER MASSES; CHROOCOCCOID CYANOBACTERIA; MARINE SYNECHOCOCCUS; PHOTOSYNTHETIC CHARACTERISTICS; NATURAL BACTERIA; DIEL PATTERNS; GROWTH; PHYTOPLANKTON; COMMUNITIES AB Single Synechococcus cells accounted for an average of 10% (range 1-26%) of surface mixed-layer primary production in Lakes Huron and Michigan in 1986-1988. Maximal photosynthetic rates (P(max)) were relatively low (range = 1.9-6.0 fg C cell-1 h-1) and no significant photoinhibition was found at irradiances as high as 3.0 Einst m-2 h-1. Synechococcus growth rates estimated by four techniques (ampicillin, C-14 uptake, dilution, and small inocula) ranged from 0.1 to 0.9 d-1 with a mean of 0.37. Although substantial variability was noted among techniques on any one date, on average all estimates were in reasonable agreement with the exception of the dilution estimates which were significantly lower (P < 0.01). Three techniques for estimating grazing loss rates (ampicillin, dilution, and C-14-labeling of Synechococcus) provided similar estimates ranging from 0.1 to 0.7 d-1. On specific dates, grazing loss rates were 33-120% of growth rates, suggesting that grazing was the major loss for Synechococcus populations in these lakes. Most of the grazing loss (68%) was attributable to small (4-10-mu-m), heterotrophic flagellates and ciliates. Crustaceans and rotifers accounted for only a small percentage of total grazing loss (5-21%) even when Daphnia accounted for 40% of crustacean biomass. C1 UNIV SO CALIF,DEPT BIOL SCI,LOS ANGELES,CA 90089. RP FAHNENSTIEL, GL (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 44 TC 66 Z9 67 U1 0 U2 2 PU AMER SOC LIMNOLOGY OCEANOGRAPH PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD MAR PY 1991 VL 36 IS 2 BP 219 EP 234 PG 16 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA FQ787 UT WOS:A1991FQ78700001 ER PT J AU FLICK, GJ ATTAWAY, DH AF FLICK, GJ ATTAWAY, DH TI ACADEMIC SCIENTISTS FACE ISSUES IN SEAFOOD TECHNOLOGY SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Editorial Material C1 NOAA,NATL SEA GRANT COLL PROGRAM,UNDERSEA RES PROGRAM,SILVER SPRING,MD 20910. RP FLICK, GJ (reprint author), VIRGINIA POLYTECH INST & STATE UNIV,DEPT FOOD SCI & TECHNOL,BLACKSBURG,VA 24061, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA 1828 L ST NW 9TH FLOOR, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD SPR PY 1991 VL 25 IS 1 BP 3 EP 3 PG 1 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA FQ076 UT WOS:A1991FQ07600001 ER PT J AU FARAHANI, M EICHMILLER, FC MCLAUGHLIN, WL AF FARAHANI, M EICHMILLER, FC MCLAUGHLIN, WL TI METAL POLYSILOXANE SHIELDS FOR RADIATION-THERAPY OF MAXILLOFACIAL TUMORS SO MEDICAL PHYSICS LA English DT Article DE DEPTH-DOSE DISTRIBUTIONS; INTERFACE DOSIMETRY; PROSTHETIC SHIELDING; RADIATION THERAPY; TELETHERAPY ID MANAGEMENT; HEAD; NECK AB In the treatment of some head and neck lesions with high-intensity radiation (teletherapy), an essential procedure is the application of an individually customized shielding appliance, which is designed, modeled, and formed into a working extra- or intraoral stent for the purpose of sparing healthy tissues. The present state of the art is slow and technique intensive, which can add to patient discomfort and inconvenience during molding and fabrication. A new formulation is described, which offers speed and ease of forming a moldable composite stent especially for intraoral use. Interleaved stacks of calibrated thin radiochromic film strips and soft-tissue-simulating plastic (polystyrene) layers gave a means of mapping one- or two-dimensional profiles of dose distributions adjacent to the high-density shielding materials using a spectrophotometer equipped with a gel scanner or a scanning laser-beam microdensitometer. Tests using collimated gamma-ray beams from a Co-60 teletherapy unit were made in order to measure the dose distribution near interfaces of tissue-simulating polymer and the composite stent material with and without mixtures of metals (Ag-Cu and Sn-Sb). These results show that quickly formed composites made of a flexible resin with high concentrations of powdered spherical metal alloys provide effective custom-designed shielding, and, with a thin overlayer of the resin without metal, a diminished back-scattered radiation dose to normal tissues. An example of a successful formulation is a mixture of 90% by weight Ag-Cu alloy powder in a vinyl polysiloxane resin. This material is a moldable putty which, upon polymerization, forms a rigid elastomeric material, providing a half-value layer of almost-equal-to 2.5 to 2.8 cm for a gamma-ray beam from a Co-60 source. C1 NATL INST STAND & TECHNOL,DIV IONIZING RADIAT,GAITHERSBURG,MD 20899. RP FARAHANI, M (reprint author), NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,PAFFENBERGER RES CTR,GAITHERSBURG,MD 20899, USA. RI Grams, Michael/G-5197-2011 NR 24 TC 13 Z9 13 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0094-2405 J9 MED PHYS JI Med. Phys. PD MAR-APR PY 1991 VL 18 IS 2 BP 273 EP 278 DI 10.1118/1.596724 PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA FH668 UT WOS:A1991FH66800019 PM 2046614 ER PT J AU NAVON, E DICK, CE BARNEA, G AF NAVON, E DICK, CE BARNEA, G TI INTENSIFYING EFFECT OF METALLIC SCREENS ON THE SENSITIVITY OF X-RAY-FILMS FOR 400-KV BREMSSTRAHLUNG PHOTONS SO MEDICAL PHYSICS LA English DT Article DE METAL SCREENS; RELATIVE PHOTOGRAPHIC EFFECT; INTENSIFICATION FACTOR; 400-KV PHOTONS; EQUILIBRIUM THICKNESS; MONTE-CARLO METHODS AB Measurements are carried out to determine the relative photographic effect produced by electrons emanating from metallic screens on a typical radiographic film. The electrons are produced in metal foils of aluminum, copper, and lead by the interaction of photons in a 400-kV bremsstrahlung beam. Intensification factors of up to 1.65, 2.05, and 5.90 for aluminum, copper, and lead screens, respectively, are determined as a function of the foil thickness. The equilibrium thickness screens are determined to be 20 mg/cm2 for aluminum and 30 mg/cm2 for copper and lead. These results are compared with the absorbed dose in the film emulsions, calculated by Monte Carlo methods. The results of the present work are compared with those for Co-60 and Cs-137 photon beams. The dependence of the equilibrium thickness and the intensification factor on photon energy and the atomic number of the screen material is summarized and explained. C1 NATL INST STAND & TECHNOL,CTR RADIAT RES,GAITHERSBURG,MD 20599. NR 6 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0094-2405 J9 MED PHYS JI Med. Phys. PD MAR-APR PY 1991 VL 18 IS 2 BP 299 EP 304 DI 10.1118/1.596725 PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA FH668 UT WOS:A1991FH66800025 PM 2046618 ER PT J AU ROWLEY, RL ELY, JF AF ROWLEY, RL ELY, JF TI NONEQUILIBRIUM MOLECULAR-DYNAMICS SIMULATIONS OF STRUCTURED MOLECULES .1. ISOMERIC EFFECTS ON THE VISCOSITY OF BUTANES SO MOLECULAR PHYSICS LA English DT Article ID LIQUID NORMAL-BUTANE; RHEOLOGICAL PROPERTIES; TRANSPORT-PROPERTIES; SHEAR VISCOSITY; SIMPLE FLUIDS; COUETTE-FLOW; N-ALKANES AB Corresponding-states theories fail to predict the large difference observed between n-butane and isobutane viscosities at similar reduced conditions. To investigate the molecular cause of these structural effects upon viscosity, non-equilibrium molecular dynamics simulations of Lennard-Jones site-site models representing n-butane and isobutane are performed over much of the density range for which experimental data are available. Simulated viscosities at zero shear agree very well with experimental data over the entire density range. Site size, non-equilibrium molecular alignment and molecular geometry are the primary factors causing both the similarities and differences between the isomers' viscosity and rheology. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. NR 23 TC 32 Z9 32 U1 1 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD MAR PY 1991 VL 72 IS 4 BP 831 EP 846 DI 10.1080/00268979100100591 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA FF457 UT WOS:A1991FF45700007 ER PT J AU TULEYA, RE AF TULEYA, RE TI SENSITIVITY STUDIES OF TROPICAL STORM GENESIS USING A NUMERICAL-MODEL SO MONTHLY WEATHER REVIEW LA English DT Article ID SEA-SURFACE TEMPERATURE AB This study investigates two cases of the FGGE III-B tropical cyclone genesis study of Tuleya (1988) in more detail. These two cases occurred within a week of one another in the tropical North Atlantic in August 1979. One disturbance developed into Hurricane David, the other did not develop past the depression stage. At one point in their evolution the disturbances had quite similar values of low-level vorticity. In the developing case of Hurricane David, the disturbance propagated along in a low-level wave trough with an accompanying high wind maximum. In the nondeveloping case the initial disturbance was also embedded in a wave trough with an associated wind maximum. This low-level wave propagated westward leaving the depression in its wake. The different environmental flow was responsible for the different behavior. Synoptic and budget analyses revealed significant differences in disturbance structure and vorticity and equivalent potential temperature tendencies at the time of approximate equal strength of the two disturbances. The evolution of these two disturbances was quite robust even to reasonable increases to the initial relative humidity. Supplementary experiments of the developing case were performed by altering the sea surface temperature and surface evaporation. It was found that the difference in storm evolution was minor in a case when climatological mean values of sea surface temperatures were specified. The climatological mean values were approximately 0.5 K lower than the August 1979 mean used in the control simulation. In addition, an experiment without evaporation led to a propagating easterly wave with little development. Furthermore, when the evaporation was specified to a climatological constant value, there was intensification into a weak tropical storm with a rather peculiar structure. Apparently, at least in this case, processes other than evaporation-wind feedback led to moderate storm intensification. RP TULEYA, RE (reprint author), NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 28 TC 8 Z9 8 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAR PY 1991 VL 119 IS 3 BP 721 EP 733 DI 10.1175/1520-0493(1991)119<0721:SSOTSG>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FF876 UT WOS:A1991FF87600008 ER PT J AU STAUFFER, DR SEAMAN, NL BINKOWSKI, FS AF STAUFFER, DR SEAMAN, NL BINKOWSKI, FS TI USE OF 4-DIMENSIONAL DATA ASSIMILATION IN A LIMITED-AREA MESOSCALE MODEL PART .2. EFFECTS OF DATA ASSIMILATION WITHIN THE PLANETARY BOUNDARY-LAYER SO MONTHLY WEATHER REVIEW LA English DT Article ID NUMERICAL WEATHER PREDICTION; INITIALIZATION; IMPACT; SCHEME AB A four-dimensional data assimilation (FDDA) scheme based on Newtonian relaxation or nudging has been developed and evaluated in the Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR) Limited-Area Mesoscale Model. It was shown in Part I of this study that continuous assimilation of standard-resolution rawinsonde observations throughout a model integration, rather than at only the initial time, can successfully limit large-scale model error growth (amplitude and phase errors) while the model maintains intervariable consistency and generates realistic mesoscale structures not resolved by the data. The purpose of this paper is to further refine the previously reported FDDA strategy used to produce "dynamic analyses" of the atmosphere by investigating the effects of data assimilation within the planetary boundary layer (PBL). The data used for assimilation include conventional synoptic-scale rawinsonde data and mesoalpha-scale surface data. The main objective of this study is to determine how to effectively utilize the combined strength of these two simple data systems while avoiding their individual weaknesses. Ten experiments, which use a 15-layer version of the model, are evaluated for two midlatitude, real-data cases. It is found that the homogenizing effect of vertical mixing during free convective conditions allows the three-hourly surface-layer wind and mixing ratio observations to be applied throughout the model PBL according to an idealized conceptual model of boundary-layer structure. Single-level surface temperature observations, however, are often poorly representative of the boundary layer as a whole (e.g., shallow superadiabatic layers, nocturnal inversions), and are more attractive for FDDA applications when additional vertical profile information is available. Assimilation of surface wind and moisture data throughout the model PBL generally showed a positive impact on the simulated precipitation by better resolving the low-level structure and movement of systems (e.g., cyclones, fronts) during the 12-h periods bracketed by the standard rawinsonde data. Improved precipitation simulations due to assimilation of surface data are also possible even in cases with weak large-scale forcing, because a significant portion of the vertically integrated moisture convergence often occurs in the boundary layer. Overall, the best dynamic analyses of precipitation, PBL depth, surface-layer temperature, and tropospheric mass and wind fields were obtained by nudging to analyses of rawinsonde wind, temperature, and moisture above the model PBL and to analyses of surface-layer wind and moisture within the model PBL. C1 NOAA,AIR RESOURCES LAB,DIV ATMOSPHER SCI MODELING,RES TRIANGLE PK,NC. RP STAUFFER, DR (reprint author), PENN STATE UNIV,DEPT METEOROL,503 WALKER BLDG,UNIVERSITY PK,PA 16802, USA. NR 28 TC 167 Z9 173 U1 0 U2 15 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAR PY 1991 VL 119 IS 3 BP 734 EP 754 DI 10.1175/1520-0493(1991)119<0734:UOFDDA>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FF876 UT WOS:A1991FF87600009 ER PT J AU BARNES, GM GAMACHE, JF LEMONE, MA STOSSMEISTER, GJ AF BARNES, GM GAMACHE, JF LEMONE, MA STOSSMEISTER, GJ TI A CONVECTIVE CELL IN A HURRICANE RAINBAND SO MONTHLY WEATHER REVIEW LA English DT Article ID DOPPLER RADAR OBSERVATIONS; INNER CORE STRUCTURE; TROPICAL CYCLONE; SCALE CHARACTERISTICS; MATURE HURRICANES; ALLEN 1980; MESOSCALE; AIRCRAFT; FIELDS; EVOLUTION AB On 10 October 1983 the two NOAA WP-3D aircraft completed a mission designed to provide airborne Doppler radar data for a convective cell embedded in a weak rainband on the trailing side of Hurricane Raymond. Comparisons of the wind field produced from the pseudo-dual-Doppler radar technique with in situ wind measurements suggest that the larger convective-scale features may be resolved if the sampling time is kept to a minimum. The convective cell was found to move downband faster than any environmental winds but slightly slower than the winds found in the reflectivity core that delineates the cell. In the core of the cell the tangential wind is increased and the radial inflow turns to outflow with respect to the circulation center. The flow field demonstrates that the downband stratiform portion of a rainband is not from cells currently active since the updraft detrains upwind relative to the cell but rather it is due to the fallout from ice particles placed into the upper troposphere by clouds that have since dissipated. The mass flux of this cell is estimated to be 5%-10% of the mass flux accomplished by an eyewall of a moderate tropical cyclone. This finding supports the concept that large, convectively active rainbands have a major effect on the subcloud layer air flowing toward the eyewall. C1 NOAA,ATLANTIC OCEANOG & METEOROL LAB,DIV HURRICANE RES,MIAMI,FL 33149. RP BARNES, GM (reprint author), NATL CTR ATMOSPHER RES,POB 300,BOULDER,CO 80307, USA. RI Gamache, John/A-9702-2014 OI Gamache, John/0000-0001-5624-0378 NR 53 TC 49 Z9 52 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAR PY 1991 VL 119 IS 3 BP 776 EP 794 DI 10.1175/1520-0493(1991)119<0776:ACCIAH>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FF876 UT WOS:A1991FF87600012 ER PT J AU SETVAK, M DOSWELL, CA AF SETVAK, M DOSWELL, CA TI THE AVHRR CHANNEL-3 CLOUD TOP REFLECTIVITY OF CONVECTIVE STORMS SO MONTHLY WEATHER REVIEW LA English DT Note ID SATELLITE C1 NOAA,ENVIRONM RES LABS,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069. CZECH HYDROMETEOROL INST,PRAGUE,CZECHOSLOVAKIA. RI Doswell III, Charles/E-7662-2010 NR 12 TC 35 Z9 38 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAR PY 1991 VL 119 IS 3 BP 841 EP 847 DI 10.1175/1520-0493(1991)119<0841:TACCTR>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FF876 UT WOS:A1991FF87600016 ER PT J AU REEDER, MJ SMITH, RK LORD, SJ AF REEDER, MJ SMITH, RK LORD, SJ TI THE DETECTION OF FLOW ASYMMETRIES IN THE TROPICAL CYCLONE ENVIRONMENT SO MONTHLY WEATHER REVIEW LA English DT Note ID MOTION AB Data from a numerical simulation of a moving barotropic vortex on a sphere with 10-km resolution are used to assess the ability of a state-of-the-art objective analysis scheme to detect certain large-scale tropical cyclone asymmetries, the so-called "beta gyres" to which the cyclone motion appears to be attributed. A series of analyses is conducted, first using the entire dataset and then taking subsets of it. Four subsets were considered in which data at a regular array of points were extracted, progressively increasing the separation between points. A fifth calculation was considered in which data were selected at points corresponding to the proposed upgraded upper-air network for a tropical cyclone motion experiment in the northwest Pacific region. It is shown that for a moderate-sized tropical cyclone-scale vortex, a regular grid spacing on the order of 100-150 km is required to adequately define the gyres, at least when the ambient flow is weak. The upgraded upper-air network was found to be inadequate by itself for this purpose, suggesting that aircraft dropwindsonde data are a prerequisite for this task. C1 UNIV MUNICH,INST METEOROL,THERESIENSTR 37,W-8000 MUNICH 2,GERMANY. NOAA,NATL WEATHER SERV,NATL METEOROL CTR,WASHINGTON,DC 20233. RI Reeder, Michael/G-2304-2011 OI Reeder, Michael/0000-0002-4583-5875 NR 9 TC 19 Z9 19 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD MAR PY 1991 VL 119 IS 3 BP 848 EP 855 DI 10.1175/1520-0493(1991)119<0848:TDOFAI>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FF876 UT WOS:A1991FF87600017 ER PT J AU COPLEY, JRD AF COPLEY, JRD TI ACCEPTANCE DIAGRAM ANALYSIS OF THE PERFORMANCE OF VERTICALLY CURVED NEUTRON MONOCHROMATORS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Vertically curved monochromator crystals are commonly used to increase the intensity on the sample in thermal neutron scattering applications. Such devices are found on spectrometers installed both at nonreflecting beam tubes and at totally reflecting guide tubes. We present an analysis of the performance of vertically curved monochromators located at instruments of both types. The acceptance diagram approach gives considerable insight into the behaviour of vertically curved monochromators. The analysis can be extended to more complicated systems, which closely represent what is actually found at a neutron scattering installation. RP COPLEY, JRD (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 6 TC 9 Z9 9 U1 0 U2 2 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 MAR 1 PY 1991 VL 301 IS 2 BP 191 EP 201 DI 10.1016/0168-9002(91)90459-4 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FE937 UT WOS:A1991FE93700003 ER PT J AU CARPENTER, JM MILDNER, DFR RICHARDSON, JW AF CARPENTER, JM MILDNER, DFR RICHARDSON, JW TI CORRECTING TIME-OF-FLIGHT NEUTRON-DIFFRACTION DATA FOR CHOPPED DELAYED NEUTRON BACKGROUNDS - THE ACTION OF A DRUM CHOPPER IN A PULSED NEUTRON BEAM SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Delayed neutron choppers in pulsed source neutron beams serve to reduce the background caused by delayed neutrons in pulsed source instruments. We analyze the effect of a drum chopper placed in an incident pulsed beam which contains delayed neutrons and compute its influenced on the detector counting rate. Expressions are found for the time and wavelength dependence of the counting rates for both prompt and delayed neutrons, in both the monitor and the scattered neutron detectors. On the basis of these results, an exact method for determining the delayed neutron background is suggested for use in measuring and correcting pulsed-source diffractometer data, by operating the chopper in random phase with respect to the source. Other approximate methods are investigated. We report measurements which confirm the analysis. C1 NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. RP CARPENTER, JM (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 6 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 MAR 1 PY 1991 VL 301 IS 2 BP 305 EP 314 DI 10.1016/0168-9002(91)90473-4 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FE937 UT WOS:A1991FE93700017 ER PT J AU CARPENTER, JM MILDNER, DFR AF CARPENTER, JM MILDNER, DFR TI TRANSMISSION PROBABILITY OF A DRUM CHOPPER IN A THERMAL-NEUTRON BEAM SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Drum choppers have been placed in the incident beams of the pulsed source instruments at IPNS (Intense Pulsed Neutron Source) in order to reduce the background resulting from delayed neutrons from the booster target. Expressions are derived for the detailed pulse shape of the transmitted neutrons and for the duration of the chopper pulse. The transmission probability depends on the neutron wavelength, the frequency of rotation of the chopper, the chopper diameter and slot width, and the incident neutron beam width. These expressions are used to compute the transmission probabilities of time-of-flight diffractometers on pulsed neutron sources which employ drum choppers. They can also be used to determine the time and wavelength dependence of the counting rates for both prompt and delayed neutrons. C1 NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. RP CARPENTER, JM (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 4 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 MAR 1 PY 1991 VL 301 IS 2 BP 315 EP 327 DI 10.1016/0168-9002(91)90474-5 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA FE937 UT WOS:A1991FE93700018 ER PT J AU TIPPIE, VK CAWLEY, JH AF TIPPIE, VK CAWLEY, JH TI MODERNIZING NOAAS OCEAN SERVICES SO OCEANUS LA English DT Article C1 NAT OCEAN SERV,ENGN STAFF,ROCKVILLE,MD. RP TIPPIE, VK (reprint author), NOAA,OCEAN SERV & COASTAL ZONE MANAGEMENT,ROCKVILLE,MD 20852, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WOODS HOLE OCEANOGRAPHIC INST PI WOODS HOLE PA OCEANUS MAGAZINE, WOODS HOLE, MA 02543 SN 0029-8182 J9 OCEANUS JI Oceanus PD SPR PY 1991 VL 34 IS 1 BP 84 EP 94 PG 11 WC Oceanography SC Oceanography GA FM134 UT WOS:A1991FM13400011 ER PT J AU WERIJ, HGC HARRIS, M COOPER, J GALLAGHER, A KELLY, JF AF WERIJ, HGC HARRIS, M COOPER, J GALLAGHER, A KELLY, JF TI COLLISIONAL ENERGY-TRANSFER BETWEEN EXCITED SR ATOMS SO PHYSICAL REVIEW A LA English DT Article ID NATURAL RADIATIVE LIFETIMES; SODIUM ATOMS; ASSOCIATIVE IONIZATION; POOLING COLLISIONS; CROSS-SECTIONS; RARE-GASES; DEACTIVATION; EXCITATION; SEQUENCES; SYSTEMS AB The following energy-transfer reactions have been observed in a Sr vapor following pulsed excitation of the 5 1P1 state: Sr*(5 1P1)+Sr*(5 1P1)-->Sr(5 1S0)+Sr**(n2S+1L)-DELTA-E, Sr*(4 1D2) +Sr*(4 1D2)-->Sr(5 1S0)+Sr**(n2S+1L)-DELTA-E. The 4 1D2 state was populated by a nonlinear stimulated process. By measuring the rate coefficients for these reactions for over 40 final states n2S+1L, we look for insight into how these reactions depend on energy defect, spin, and angular momentum. It is found that there is not a very strong dependence on the energy defect, and that singlet and triplet final states are produced in comparable amounts. The final states tend to be populated more effectively as their angular momentum increases. Total rate coefficients are of the order of gas-kinetic rates. C1 UNIV COLORADO,NIST,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV IDAHO,DEPT PHYS,MOSCOW,ID 83843. NR 33 TC 16 Z9 19 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR 1 PY 1991 VL 43 IS 5 BP 2237 EP 2249 DI 10.1103/PhysRevA.43.2237 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA EZ702 UT WOS:A1991EZ70200013 ER PT J AU LINDLE, DW COWAN, PL JACH, T LAVILLA, RE DESLATTES, RD PERERA, RCC AF LINDLE, DW COWAN, PL JACH, T LAVILLA, RE DESLATTES, RD PERERA, RCC TI POLARIZED X-RAY-EMISSION STUDIES OF METHYL-CHLORIDE AND THE CHLOROFLUOROMETHANES SO PHYSICAL REVIEW A LA English DT Article ID SYNCHROTRON RADIATION BEAMLINE; VALENCE ELECTRON-SPECTRA; INNER-SHELL EXCITATION; HIGH-ENERGY-RESOLUTION; PHOTOELECTRON-SPECTRA; ABSORPTION-SPECTRA; SUBSTITUTED METHANES; VACUUM ULTRAVIOLET; ORGANIC-MOLECULES; SPECTROSCOPY AB A new technique sensitive to molecular orientation and geometry, and based on measuring the polarization of x-ray emission, has been applied to the Cl-containing molecules methyl chloride (CH3Cl) and the chlorofluoromethanes (CF3Cl, CF2Cl2, and CFCl3) in the gas phase. Upon selective excitation using monochromatic synchrotron radiation in the Cl K-edge (Cl ls) near-threshold region, polarization-selective x-ray emission studies reveal highly polarized molecular valence x-ray fluorescence for all four molecules. The degree and the orientation of the polarized emission are observed to be sensitive to the incident excitation energy near the Cl K edge. In some cases, the polarization direction for x-ray emission reverses for small changes in incident excitation energy (a few eV). It is shown that the polarized x-ray emission technique can be used to infer, directly from experiment, symmetries of occupied and unoccupied valence molecular orbitals, anisotropies in absorption and emission, and orientational and geometrical information. It is suggested that the x-ray polarized-fluorescence phenomenon, reported here for simple molecules, can be used as a new approach to study more complicated systems in a variety of environments. C1 UNIV CALIF BERKELEY LAWRENCE BERKELEY LAB,DIV ACCELERATOR & FUS RES,ADV LIGHT SOURCE,BERKELEY,CA 94720. RP LINDLE, DW (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 69 TC 37 Z9 37 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR 1 PY 1991 VL 43 IS 5 BP 2353 EP 2366 DI 10.1103/PhysRevA.43.2353 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA EZ702 UT WOS:A1991EZ70200026 ER PT J AU REDFORS, A READER, J AF REDFORS, A READER, J TI SPECTRUM AND ENERGY-LEVELS OF THE XENONLIKE ION CE-V SO PHYSICAL REVIEW A LA English DT Article ID CS-II; IV AB The spectrum of four-times ionized cerium Ce V has been observed with a sliding-spark discharge and a 10.7-m normal-incidence vacuum spectrograph. A total of 107 lines have been classified as transitions between 51 energy levels. All levels of the 5p6, 5p(5)4f, 5p(5)5d, 5p(5)6s, 5p(5)6p, and 5p(5)6d configurations have been determined. Because of collapse of the 4f shell, the 5p(5)4f configuration is situated well below 5p(5)5d. Ab initio calculations and least-squares fits of the energy parameters to the experimental energy levels are reported. The ionization energy is revised to 527 100 +/- 2000 cm-1 (65.35 +/- 0.25 eV). C1 NIST,GAITHERSBURG,MD 20899. RP REDFORS, A (reprint author), UNIV LUND,DEPT PHYS,S-22101 LUND,SWEDEN. RI Redfors, Andreas/G-8461-2014 OI Redfors, Andreas/0000-0003-4792-8749 NR 14 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD MAR 1 PY 1991 VL 43 IS 5 BP 2367 EP 2373 DI 10.1103/PhysRevA.43.2367 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA EZ702 UT WOS:A1991EZ70200027 ER PT J AU MCKINNON, WR TSELEPIS, E TARASCON, JM MICELI, PF REMSCHNIG, K HULL, GW NEUMANN, DA RHYNE, JJ AF MCKINNON, WR TSELEPIS, E TARASCON, JM MICELI, PF REMSCHNIG, K HULL, GW NEUMANN, DA RHYNE, JJ TI WEAK FERROMAGNETISM AND CANTING IN BIPBSR2MNO6 AND BIPBCA2MNO6 SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC-PROPERTIES; SUPERCONDUCTOR AB The magnetic behavior of single crystals and powders of BiPbSr2MnO6 and BiPbCa2MnO6 has been measured between 300 and 4 K. These analogues of the high-temperature superconducting bismuth cuprates have no structural modulation, and consequently do not have the sharp peak in magnetization found in modulated Bi2Sr2MnO6+delta. Instead, their magnetic behavior is consistent with antiferromagnetism (below transition temperatures near 150 K in crystals and 200 K in powders) with the spins mainly oriented normal to the MnO2 planes, as confirmed by neutron diffraction. They also show weak ferromagnetism, with a remanent moment in the MnO2 planes; this is interpreted as small canting (less than 0.1-degrees) of the spins toward the MnO2 planes. C1 BELL COMMUN RES INC,RED BANK,NJ 07701. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP MCKINNON, WR (reprint author), NATL RES COUNCIL CANADA,OTTAWA K1A 0R9,ONTARIO,CANADA. RI Tarascon, Jean-Marie/B-5952-2016 NR 12 TC 8 Z9 8 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD MAR 1 PY 1991 VL 43 IS 7 BP 5468 EP 5473 DI 10.1103/PhysRevB.43.5468 PN A PG 6 WC Physics, Condensed Matter SC Physics GA FA992 UT WOS:A1991FA99200033 ER PT J AU PAULTER, NG MAJUMDAR, AK AF PAULTER, NG MAJUMDAR, AK TI A NEW TRIPLE CORRELATION TECHNIQUE FOR MEASURING ULTRASHORT LASER-PULSES SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID PHASE; AMPLITUDE AB A new triple correlation technique for measuring the complete intensity profile of ultrashort optical pulses is described. The triple correlation preserves the phase information of the input pulse so that a reconstruction of the triply correlated signal will provide a unique reconstruction of the input. The new technique described here uses two second-order, nonlinear optical interactions for the generation of a triply correlated signal. A derivation of the measured triple-correlation signal and the pulse reconstruction is given. The effects of noise on the measured signal are also examined. C1 UNIV COLORADO,DEPT ELECT ENGN,DENVER,CO 80202. RP PAULTER, NG (reprint author), NIST,DIV ELECTROMAGNET FIELDS,BOULDER,CO 80303, USA. NR 24 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAR PY 1991 VL 62 IS 3 BP 567 EP 578 DI 10.1063/1.1142108 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA EZ923 UT WOS:A1991EZ92300001 ER PT J AU RICE, P MORELAND, J AF RICE, P MORELAND, J TI A NEW LOOK AT THE BITTER METHOD OF MAGNETIC IMAGING SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Note AB A scanning tunneling microscope (STM) was used in place of an optical microscope in the Bitter method to image the magnetic ferrofluid particles on the surface of a hard disk. The resolution obtainable with the usual Bitter method is limited by the optical viewing of the magnetic particles. Using the scanning tunneling microscope, we have obtained image resolution limited only by the ferrofluid particle size. RP RICE, P (reprint author), NIST,DIV ELECTROMAGNET TECHNOL,SUPERCONDUCTOR & MAGNET MEASUREMENTS GRP,BOULDER,CO 80303, USA. NR 4 TC 7 Z9 7 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAR PY 1991 VL 62 IS 3 BP 844 EP 845 DI 10.1063/1.1142048 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA EZ923 UT WOS:A1991EZ92300050 ER PT J AU RODEL, J KELLY, JF STOUDT, MR BENNISON, SJ AF RODEL, J KELLY, JF STOUDT, MR BENNISON, SJ TI A LOADING DEVICE FOR FRACTURE TESTING OF COMPACT TENSION SPECIMENS IN THE SCANNING ELECTRON-MICROSCOPE SO SCANNING MICROSCOPY LA English DT Article DE SCANNING ELECTRON MICROSCOPY; CRACKS; CRACK PROFILE; INSITU; FRACTURE TOUGHNESS; MICROSTRUCTURE; ALUMINA ID BRITTLE MATERIALS; CRACK-RESISTANCE; CERAMICS; ALUMINA AB A loading device for performing fracture experiments on compact tension specimens in the SEM has been designed. Its key elements are a piezoelectric translator for applying controlled displacements to the loading points on the specimen and a load cell to measure applied loads. The effective transmission of displacement from the piezoelectric driver to the specimen was found to be the major mechanical design problem. The peripheral equipment includes a function generator and a high voltage amplifier that drives the piezoelectric translator as well as a video overlay and standard video equipment to record the image continuosuly during the course of the experiment. A case study on alumina describes qualitative observations on the toughening mechanism, crack-interface bridging, operating in this material. Quantitative information pertaining to the closure stresses associated with this toughening mode can be obtained by measuring the crack profile. C1 NATL INST STAND & TECHNOL,DIV CERAM,BLDG 223,ROOM A256,GAITHERSBURG,MD 20899. NR 19 TC 24 Z9 24 U1 1 U2 2 PU SCANNING MICROSCOPY INT PI CHICAGO PA PO BOX 66507, AMF O'HARE, CHICAGO, IL 60666 SN 0891-7035 J9 SCANNING MICROSCOPY JI Scanning Microsc. PD MAR PY 1991 VL 5 IS 1 BP 29 EP 35 PG 7 WC Microscopy SC Microscopy GA FH432 UT WOS:A1991FH43200003 ER PT J AU KARL, TR HEIM, RR QUAYLE, RG AF KARL, TR HEIM, RR QUAYLE, RG TI THE GREENHOUSE-EFFECT IN CENTRAL NORTH-AMERICA - IF NOT NOW, WHEN SO SCIENCE LA English DT Article ID TIME-SERIES; DROUGHT AB Climate models with enhanced greenhouse gas concentrations have projected temperature increases of 2-degrees to 4-degrees-C, winter precipitation increases of up to 15 percent, and summer precipitation decreases of 5 to 10 percent in the central United States by the year 2030. An analysis of the climate record over the past 95 years for this region was undertaken in order to evaluate these projections. Results indicate that temperature has increased and precipitation decreased both during winter and summer, and that the ratio of winter-to-summer precipitation has decreased. The signs of some trends are consistent with the projections whereas others are not, but none of the changes is statistically significant except for maximum and minimum temperatures, which were not among the parameters predicted by the models. Statistical models indicate that the greenhouse winter and summer precipitation signal could have been masked by natural climate variability, whereas the increase in the ratio of winter-to-summer precipitation and the higher rates of temperature change probably should have already been detected. If the models are correct it will likely take at least another 40 years before statistically significant precipitation changes are detected and another decade or two to detect the projected changes of temperature. RP KARL, TR (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,NATL CLIMAT DATA CTR,GLOBAL CLIMATE LAB,ASHEVILLE,NC 28801, USA. NR 16 TC 61 Z9 61 U1 0 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAR 1 PY 1991 VL 251 IS 4997 BP 1058 EP 1061 DI 10.1126/science.251.4997.1058 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA EZ665 UT WOS:A1991EZ66500045 PM 17802090 ER PT J AU IYENGAR, GV AF IYENGAR, GV TI MILESTONES IN BIOLOGICAL TRACE-ELEMENT RESEARCH SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article AB Over 100 years ago, macro-scale analytical techniques were used to discover the roles of special compounds (especially of metallic elements) in living organisms, and investigations were focussed on selected proteins and pigments suspected of containing percentage quantities of metals. In contrast, present-day analytical techniques are capable of detecting extremely small quantities and have become routine ultra-trace measurement tools to probe elemental interactions at cellular levels. The scientific achievements connecting these two boundaries are punctuated with an array of analytical developments; some highlighting the phenomenal advances in the measurement technology and others reflecting the exceptional bioanalytical perception and the multi-disciplinary outlook of trace element investigators. An account of the events that contributed to the overall progress in biological trace element research is the essence of this communication. RP IYENGAR, GV (reprint author), US DEPT COMMERCE,NATL INST STAND & TECHNOL,BLDG 235,B125,GAITHERSBURG,MD 20899, USA. NR 51 TC 23 Z9 23 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD MAR PY 1991 VL 100 BP 1 EP 15 DI 10.1016/0048-9697(91)90370-T PG 15 WC Environmental Sciences SC Environmental Sciences & Ecology GA FD260 UT WOS:A1991FD26000003 PM 2063177 ER PT J AU CARTER, WC BUTLER, EP FULLER, ER AF CARTER, WC BUTLER, EP FULLER, ER TI MICROMECHANICAL ASPECTS OF ASPERITY-CONTROLLED FRICTION IN FIBER-TOUGHENED CERAMIC COMPOSITES SO SCRIPTA METALLURGICA ET MATERIALIA LA English DT Article C1 LEHIGH UNIV,DEPT MAT SCI & ENGN,BETHLEHEM,PA 18015. RP CARTER, WC (reprint author), NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899, USA. RI Carter, W/K-2406-2012 NR 8 TC 63 Z9 63 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0956-716X J9 SCRIPTA METALL MATER JI Scr. Metall. Materialia PD MAR PY 1991 VL 25 IS 3 BP 579 EP 584 DI 10.1016/0956-716X(91)90095-I PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA EZ877 UT WOS:A1991EZ87700015 ER PT J AU BOISVERT, RF AF BOISVERT, RF TI ALGORITHMS FOR SPECIAL TRIDIAGONAL SYSTEMS SO SIAM JOURNAL ON SCIENTIFIC AND STATISTICAL COMPUTING LA English DT Article DE DIAGONALLY DOMINANT MATRICES; FOURIER METHOD; LU FACTORIZATION; NEUMANN BOUNDARY CONDITIONS; PERIODIC BOUNDARY CONDITIONS; POISSON EQUATION; REVERSED TRIANGULAR FACTORIZATION; SYMMETRICAL MATRICES; TOEPLITZ MATRICES; TRIDIAGONAL MATRICES ID CYCLIC REDUCTION ALGORITHM; LINEAR-SYSTEMS; EQUATION AB Algorithms for the solution of symmetric diagonally dominant tridiagonal systems of linear equations with constant diagonals are considered. Such systems occur, for example, when solving certain constant-coefficient elliptic partial differential equations by the Fourier method. In particular, the specialized LU factorization method of Malcolm and Palmer (SpLU), the cyclic reduction method of Hockney (CR), and the reversed triangular factorization method of Evans (RTF) are considered. An interesting property of the first two algorithms is that they may be terminated early for highly diagonally dominant systems. A new implementation of RTF that also has this property is presented, significantly reducing its operation count in many cases. The slightly perturbed systems that arise from problems with Neumann or periodic boundary conditions are also considered, with extensions given for SpLU to the periodic case and RTF to the Neumann case. Floating-point operation counts are given for each method, and the results of experiments on a single scalar processor are reported. RP BOISVERT, RF (reprint author), NATL INST STAND & TECHNOL,CTR COMP & APPL MATH,GAITHERSBURG,MD 20899, USA. OI Boisvert, Ronald/0000-0002-4445-1044 NR 19 TC 19 Z9 21 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER PH#382-9800, PHILADELPHIA, PA 19104-2688 SN 0196-5204 J9 SIAM J SCI STAT COMP PD MAR PY 1991 VL 12 IS 2 BP 423 EP 442 DI 10.1137/0912023 PG 20 WC Mathematics, Applied SC Mathematics GA EX673 UT WOS:A1991EX67300011 ER PT J AU MILLY, PCD AF MILLY, PCD TI A REFINEMENT OF THE COMBINATION EQUATIONS FOR EVAPORATION SO SURVEYS IN GEOPHYSICS LA English DT Review AB Most combination equations for evaporation rely on a linear expansion of the saturation vapor-pressure curve around the air temperature. Because the temperature at the surface may differ from this temperature by several degrees, and because the saturation vapor-pressure curve is nonlinear, this approximation leads to a certain degree of error in those evaporation equations. It is possible, however, to introduce higher-order polynomial approximations for the saturation vapor-pressure curve and to derive a family of explicit equations for evaporation, having any desired degree of accuracy. Under the linear approximation, the new family of equations for evaporation reduces, in particular cases, to the combination equations of H. L. Penman (Natural evaporation from open water, bare soil and grass, Proc. R. Soc. London, Ser. A 193, 120-145, 1948) and of subsequent workers. Comparison of the linear and quadratic approximations leads to a simple approximate expression for the error associated with the linear case. Equations based on the conventional linear approximation consistently underestimate evaporation, sometimes by a substantial amount. RP MILLY, PCD (reprint author), NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 13 TC 19 Z9 19 U1 0 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0169-3298 J9 SURV GEOPHYS JI Surv. Geophys. PD MAR PY 1991 VL 12 IS 1-3 BP 145 EP 154 DI 10.1007/BF01903416 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA EU405 UT WOS:A1991EU40500008 ER PT J AU ALNASSAR, YN DATTA, SK SHAH, AH AF ALNASSAR, YN DATTA, SK SHAH, AH TI SCATTERING OF LAMB WAVES BY A NORMAL RECTANGULAR STRIP WELDMENT SO ULTRASONICS LA English DT Article DE LAMB WAVES; WAVE SCATTERING; NUMERICAL MODELS; COMBINED FINITE ELEMENT AND ANALYTICAL TECHNIQUE ID FINITE-ELEMENT ANALYSIS; PLATE; RESONANCE AB A combined finite element and Lamb wave modal expansion method is presented here for analysing scattering of time harmonic Lamb waves by material and geometric irregularities in an isotropic linearly elastic infinite plate. All the irregularities are assumed to be contained in a bounded region. The method is to replace this region with a finite element mesh. A nodal force-displacement relation is developed to satisfy the continuity conditions along the artificial boundaries separating the inner finite element region from the exterior regular region. The method is illustrated by solving the problem of scattering of Lamb waves by a normal transversely anisotropic weldment. The reflection and transmission coefficients are computed for the first antisymmetric and symmetric incident modes. The validity and accuracy of the results are checked by satisfaction of the energy conservation principle. C1 UNIV COLORADO,CTR SPACE CONSTRUCT,BOULDER,CO 80309. UNIV MANITOBA,DEPT CIVIL ENGN,WINNIPEG R3T 2N2,MANITOBA,CANADA. RP ALNASSAR, YN (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,DEPT MECH ENGN,BOULDER,CO 80309, USA. NR 18 TC 77 Z9 80 U1 0 U2 8 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0041-624X J9 ULTRASONICS JI Ultrasonics PD MAR PY 1991 VL 29 IS 2 BP 125 EP 132 DI 10.1016/0041-624X(91)90041-6 PG 8 WC Acoustics; Radiology, Nuclear Medicine & Medical Imaging SC Acoustics; Radiology, Nuclear Medicine & Medical Imaging GA FD326 UT WOS:A1991FD32600003 ER PT J AU BOND, LJ AF BOND, LJ TI REVIEW OF PROGRESS IN QUANTITATIVE NDE LA-JOLLA, CA, USA, 15-20 JULY 1990 SO ULTRASONICS LA English DT Editorial Material C1 NATL INST STAND & TECHNOL,BOULDER,CO. RP BOND, LJ (reprint author), UNIV COLORADO,BOULDER,CO 80309, USA. NR 0 TC 0 Z9 0 U1 2 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0041-624X J9 ULTRASONICS JI Ultrasonics PD MAR PY 1991 VL 29 IS 2 BP 177 EP 178 PG 2 WC Acoustics; Radiology, Nuclear Medicine & Medical Imaging SC Acoustics; Radiology, Nuclear Medicine & Medical Imaging GA FD326 UT WOS:A1991FD32600012 ER PT J AU KANE, RJ AF KANE, RJ TI CORRELATING LIGHTNING TO SEVERE LOCAL STORMS IN THE NORTHEASTERN UNITED-STATES SO WEATHER AND FORECASTING LA English DT Article AB Two tornado events and an intense downburst episode were investigated in an attempt to relate cloud-to-ground lightning rates with the occurrence of severe local storms. The State University of New York at Albany lightning detection system was used to yield characteristic lightning rate tendencies and particular lightning signatures that were associated with severe storms in the northeastern United States. Tornadoes and large hail occurred about 10-15 min after a pronounced peak in the 5-min cloud-to-ground lightning rate. In the downburst event, very destructive winds occurred just after the 5-min rate peaked. Because these severe local storm activities followed well-defined peaks in the 5-min cloud-to-ground lightning rate, it may be possible that the 5-min rates could be used operationally to forecast severe weather. RP KANE, RJ (reprint author), NOAA,NATL WEATHER SERV FORECAST OFF,RD 1,BOX 107,STERING,VA 22170, USA. NR 0 TC 22 Z9 22 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1991 VL 6 IS 1 BP 3 EP 12 DI 10.1175/1520-0434(1991)006<0003:CLTSLS>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FC635 UT WOS:A1991FC63500001 ER PT J AU BROWN, RA WOOD, VT AF BROWN, RA WOOD, VT TI ON THE INTERPRETATION OF SINGLE-DOPPLER VELOCITY PATTERNS WITHIN SEVERE THUNDERSTORMS SO WEATHER AND FORECASTING LA English DT Article AB Although the flow field within a severe thunderstorm is complex, it is possible to simulate the basic features using simple analytical flow models (such as uniform flow, axisymmetric rotation, axisymmetric divergence). Combinations of such flow models are used to produce simulated Doppler velocity patterns that can be used as "signatures" for identifying quasi-horizontal flow features within severe thunderstorms. Some of these flow features are: convergence in the lower portions of a storm and divergence in the upper portions associated with a strong updraft, surface divergence associated with a wet or dry downdraft, mesocyclone (rotating updraft), flow around an updraft obstacle, and tornado. Recognition of the associated Doppler velocity patterns can aid in the interpretation of single-Doppler radar measurements that include only the radial component of flow in the radar viewing direction. RP BROWN, RA (reprint author), NOAA,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 0 TC 32 Z9 34 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1991 VL 6 IS 1 BP 32 EP 48 DI 10.1175/1520-0434(1991)006<0032:OTIOSD>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FC635 UT WOS:A1991FC63500003 ER PT J AU WATSON, AI HOLLE, RL LOPEZ, RE ORTIZ, R NICHOLSON, JR AF WATSON, AI HOLLE, RL LOPEZ, RE ORTIZ, R NICHOLSON, JR TI SURFACE WIND CONVERGENCE AS A SHORT-TERM PREDICTOR OF CLOUD-TO-GROUND LIGHTNING AT KENNEDY-SPACE-CENTER SO WEATHER AND FORECASTING LA English DT Article AB Cloud-to-ground lightning is a significant forecast problem at the Kennedy Space Center (KSC) in Florida. In this study, cloud-to-ground lightning is related in time and space to surface convergence for 244 days during the convective seasons of 1985 and 1986 over a 790-km2 network at KSC. The method uses surface convergence, particularly the average over the area, to identify the potential for new, local thunderstorm growth, and it can be used to specify the likely time and location of lightning during the life cycle of the convection. A threshold of 75 x 10(-6) S-1 change in divergence is the main criterion used to define a convergence event, and a set of flashes less than 30 min apart defines a lightning event. Time intervals are found from the study to be approximately 1 h from beginning convergence to first flash, and another hour to the end of lightning. The influences of low-level winds and midlevel moisture in determining the location and intensity of convection are discussed. This is the first known dynamically-based forecast method for lightning prediction. The technique, currently in use at KSC, has been shown to be a systematic, quantitative tool for predicting lightning onset in situations where conventional analysis tool such as radar and satellite are limited. RP WATSON, AI (reprint author), NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,MESOSCALE RES DVN,R-E-NS1,325 BROADWAY,BOULDER,CO 80303, USA. NR 0 TC 21 Z9 22 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1991 VL 6 IS 1 BP 49 EP 64 DI 10.1175/1520-0434(1991)006<0049:SWCAAS>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FC635 UT WOS:A1991FC63500004 ER PT J AU DUNN, LB AF DUNN, LB TI EVALUATION OF VERTICAL MOTION - PAST, PRESENT, AND FUTURE SO WEATHER AND FORECASTING LA English DT Article AB The potential impact of gridded output from numerical models on operational forecasting of vertical motion is examined. A review of historical techniques for operational vertical motion evaluation is presented. An attempt is made to relate previous methods with current operational techniques, and to contrast these with techniques that could be applied operationally via the use of gridded model output. This paper makes the point that most of the current operational practices for the estimation of vertical motion and the general interpretation of numerical model output are based on techniques that were originally used to create surface and upper air prognoses manually in the pre-NWP era, and are no longer appropriate or optimal. Unfortunately the tools available to operational forecasters are also a remnant of this same era. Gridded data from numerical models have the potential to greatly change operational methods of vertical motion estimation and general interpretation of numerical models. RP DUNN, LB (reprint author), NOAA,NATL WEATHER SERV WESTERN REG,DIV SCI SERV,POB 11188,FED BLDG,SALT LAKE CITY,UT 84147, USA. NR 0 TC 15 Z9 27 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1991 VL 6 IS 1 BP 65 EP 75 DI 10.1175/1520-0434(1991)006<0065:EOVMPP>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FC635 UT WOS:A1991FC63500005 ER PT J AU ERICKSON, MC BOWER, JB DAGOSTARO, VJ DALLAVALLE, JP JACKS, E JENSENIUS, JS SU, JC AF ERICKSON, MC BOWER, JB DAGOSTARO, VJ DALLAVALLE, JP JACKS, E JENSENIUS, JS SU, JC TI EVALUATING THE IMPACT OF RAFS CHANGES ON THE NGM-BASED MOS GUIDANCE SO WEATHER AND FORECASTING LA English DT Note AB In the spring of 1990, the National Meteorological Center (NMC) tested several modifications to the Regional Analysis and Forecast System (RAFS). In order to compare the proposed version of the RAFS to the current operational RAFS, NMC ran both systems in parallel for a 4-week period. Simultaneously, the Techniques Development Laboratory (TDL) applied the operational RAFS-based Model Output Statistics (MOS) equations to output from both the operational and proposed (parallel) versions of the Nested Grid Model (NGM) to generate two sets of MOS forecasts. Our goal was to determine the impact of RAFS modifications on the NGM MOS forecasts. At the end of the 4-week test period, we verified both the operational and parallel NGM MOS forecasts. Virtually no differences in accuracy or skill existed between the operational and parallel MOS forecasts of max/min temperature, probability of precipitation, and surface wind. The skill of the cloud amount forecasts, however, deteriorated significantly. The NGM 300-mb relative humidity field changed markedly as a result of the RAFS modifications, and this change affected the cloud forecasts. Since the cloud cover forecasts were the only NGM MOS products adversely impacted by the new parallel RAFS, we rederived the cloud equations without the 300-mb relative humidity. These equations were implemented operationally in September 1990. When the new RAFS is implemented, we expect that the impact on the current NGM MOS guidance will be minimal. RP ERICKSON, MC (reprint author), NOAA,NATL WEATHER SERV,OFF SYST DEV,TECHNIQUES DEV LAB,5200 AUTH RD,ROOM 706,CAMP SPRINGS,MD 20746, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1991 VL 6 IS 1 BP 142 EP 147 DI 10.1175/1520-0434(1991)006<0142:ETIORC>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FC635 UT WOS:A1991FC63500013 ER PT J AU SIEWERT, TA GERKEN, JM AF SIEWERT, TA GERKEN, JM TI WELDING TECHNOLOGY IN EASTERN-EUROPE SO WELDING JOURNAL LA English DT Article C1 LINCOLN ELECT CO,TECHNOL TRANSFER,CLEVELAND,OH. RP SIEWERT, TA (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 SN 0043-2296 J9 WELD J JI Weld. J. PD MAR PY 1991 VL 70 IS 3 BP 49 EP 52 PG 4 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA EZ785 UT WOS:A1991EZ78500006 ER PT J AU WEICKMANN, KM AF WEICKMANN, KM TI EL-NINO SOUTHERN OSCILLATION AND MADDEN-JULIAN (30-60 DAY) OSCILLATIONS DURING 1981-1982 SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article; Proceedings Paper CT WESTERN PACIFIC INTERNATIONAL MEETING AND WORKSHOP ON TOGA/COARE ( TROPICAL OCEAN GLOBAL ATMOSPHERE/COUPLED OCEAN-ATMOSPHERE RESPONSE EXPERIMENT ) CY MAY 24-30, 1989 CL CTR ORSTOM NOUMEA, NOUMEA, NEW CALEDONIA HO CTR ORSTOM NOUMEA ID SEA-SURFACE TEMPERATURE; OUTGOING LONGWAVE RADIATION; INTRASEASONAL OSCILLATIONS; INTERANNUAL VARIABILITY; TROPICAL ATMOSPHERE; PACIFIC; ANOMALIES; WIND; CIRCULATION; HEMISPHERE AB An important issue in understanding the low-frequency oscillations of the atmosphere and the ocean-atmosphere system concerns the role of transients during individual events. This question is examined from an observational point of view for the period from September 1981 to April 1982, which includes the transitional phase of the 1982-1983 El Nino/Southern Oscillation (ENSO) cycle, as well as six Madden-Julian (30-60 day) oscillations (MJO). For the developing ENSO, it is shown that interannual transitions in the anomalous atmospheric circulation and in the sea surface temperatures in the western-central Pacific coincide with the passage of strong MJOs from the Indian to Pacific oceans. For a MJO during December 1981, evidence is provided that the shift of convection from the eastern Indian Ocean to the western Pacific Ocean involves transients having periods around 10 days. The role of transients is discussed from the perspective of these interannual and intraseasonal modes. RP WEICKMANN, KM (reprint author), NOAA,ENVIRONM RES LABS,R-E-CG2,325 BROADWAY,BOULDER,CO 80303, USA. NR 45 TC 51 Z9 54 U1 1 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 28 PY 1991 VL 96 SU S BP 3187 EP 3195 PG 9 WC Oceanography SC Oceanography GA FB521 UT WOS:A1991FB52100006 ER PT J AU GAGE, KS BALSLEY, BB ECKLUND, WL CARTER, DA MCAFEE, JR AF GAGE, KS BALSLEY, BB ECKLUND, WL CARTER, DA MCAFEE, JR TI WIND PROFILER RELATED RESEARCH IN THE TROPICAL PACIFIC SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article; Proceedings Paper CT WESTERN PACIFIC INTERNATIONAL MEETING AND WORKSHOP ON TOGA/COARE ( TROPICAL OCEAN GLOBAL ATMOSPHERE/COUPLED OCEAN-ATMOSPHERE RESPONSE EXPERIMENT ) CY MAY 24-30, 1989 CL CTR ORSTOM NOUMEA, NOUMEA, NEW CALEDONIA HO CTR ORSTOM NOUMEA ID OUTGOING LONGWAVE RADIATION; 40-50 DAY OSCILLATION; SOUTHERN OSCILLATION; CLOUD CLUSTERS; DOPPLER RADAR; SQUALL LINE; ATMOSPHERE; WINTER; CONVECTION; POHNPEI AB This paper is concerned with the application of wind-profiling Doppler radar technology to tropical atmospheric research. Examples of the use of wind profilers in the tropics are drawn from the Aeronomy Laboratory's wind profilers located on Pohnpei, Micronesia (7-degrees-N, 158-degrees-E), and Christmas Island (2-degrees-N, 157-degrees-W). The Pohnpei wind profiler was constructed in 1984 and has been used exclusively to observe vertical motions. The Christmas Island wind profiler has observed horizontal and vertical velocities routinely since 1986. These two wind profilers form part of a planned trans-Pacific network of wind-profiling radars that will eventually span the tropical Pacific. RP GAGE, KS (reprint author), NOAA,ENVIRONM RES LABS,AERON LAB,R-E-AL2,325 BROADWAY,BOULDER,CO 80303, USA. NR 32 TC 39 Z9 39 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 28 PY 1991 VL 96 SU S BP 3209 EP 3220 PG 12 WC Oceanography SC Oceanography GA FB521 UT WOS:A1991FB52100008 ER PT J AU HARRISON, DE GIESE, BS AF HARRISON, DE GIESE, BS TI EPISODES OF SURFACE WESTERLY WINDS AS OBSERVED FROM ISLANDS IN THE WESTERN TROPICAL PACIFIC SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID EL-NINO; SOUTHERN OSCILLATION; EQUATORIAL PACIFIC; FLUCTUATIONS; OCEAN AB We describe the characteristics of surface westerly wind episodes in the tropical Pacific between mid-1957 and 1980, as they can be determined from a collection of daily average wind records from islands. Several types of frequency of occurrence and duration statistics are presented; events in which the maximum westerly anomalies exceed 7 m s-1 are not common, but are prominent in the records. There is strong seasonal and geographical variation in frequency of occurrence. Four types of westerly episodes are found; we call them types N, C, S, or FS, according to whether the maximum westerly wind is found north of, centered on, south of, or "far south" of the equator near the international date line. Sixteen, 45, 47, and 47 events of type N, C, S, and FS are identified, respectively. The strongest westerly winds are associated with type C and S events; maximum daily average values can exceed 20 m s-1. Only type C and S events are found to have substantial equatorial zonal wind anomalies. Several examples of type C and S events presented. Composite events of each type have been computed, and their characteristics are described. In order to explore relationships between equatorial westerly events and cyclones, all of the named tropical cyclones within a region encompassing the near-date line islands have been identified; various statistics are presented, but no absolute relationships have been identified. The similarity between the composite type C and S anomaly patterns and patterns of the El Nino-Southern Oscillation monthly mean zonal wind anomaly previously documented in the literature is striking; evidently, the westerly events often dominate in the monthly average anomaly. RP HARRISON, DE (reprint author), NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. RI Harrison, Don/D-9582-2013 NR 18 TC 56 Z9 58 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 28 PY 1991 VL 96 SU S BP 3221 EP 3237 DI 10.1029/90JC01775 PG 17 WC Oceanography SC Oceanography GA FB521 UT WOS:A1991FB52100009 ER PT J AU GIESE, BS HARRISON, DE AF GIESE, BS HARRISON, DE TI EASTERN EQUATORIAL PACIFIC RESPONSE TO 3 COMPOSITE WESTERLY WIND TYPES SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID EL-NINO; KELVIN WAVES; SOUTHERN OSCILLATION; OCEAN; CURRENTS; BURST AB It has been suggested recently that episodes of westerly wind near the international date line in the western Pacific tend to fall into one of four types. Three of the types have enough equatorial zonal wind variation to be able to induce an eastern Pacific response by forcing equatorial waves. In this note we examine the central and eastern Pacific waveguide response to idealized representations of these three types of westerly wind episodes, using a combination of linear theory and results from an ocean general circulation model. The idealized westerly wind types are the C type (maximum anomalies centered on the equator), the N type (maximum anomalies just north of the equator), and the S type (maximum anomalies just south of the equator). The composite C-type event excites equatorially trapped Kelvin pulses that alter sea surface temperature in the central and eastern Pacific. Warm anomalies caused by the C-type episode have approximately equal contributions from a zonal advection of heat by the Kelvin pulses and a meridional advection of heat by an altered instability wave field. Because the center of forcing of the S-type event is displaced off of the equator, the Kelvin pulses excited by the S-type episode have smaller amplitude than those of the C-type episode, even though the maximum wind anomaly is the same in the two cases. The S-type anomaly also excites weak Rossby-gravity waves that can propagate into the eastern Pacific. Because the Rossby-gravity waves are dispersive, their amplitude diminishes as the waves propagate into the eastern Pacific. The N-type episode, as observed in winds from the western tropical Pacific, is much weaker and of shorter duration than the C and S types, and therefore excites only a very weak eastern Pacific response. Although all types of westerly wind excite a local western Pacific response, only the C- and S-type events excite a significant eastern Pacific response. C1 NOAA, PACIFIC MARINE ENVIRONM LAB, SEATTLE, WA 98115 USA. UNIV CORP ATMOSPHER RES, BOULDER, CO USA. RP GIESE, BS (reprint author), UNIV CALIF SAN DIEGO, SCRIPPS INST OCEANOG, CLIMATE RES GRP A024, LA JOLLA, CA 92093 USA. RI Harrison, Don/D-9582-2013 NR 25 TC 51 Z9 53 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 28 PY 1991 VL 96 SU S BP 3239 EP 3248 DI 10.1029/90JC01861 PG 10 WC Oceanography SC Oceanography GA FB521 UT WOS:A1991FB52100010 ER PT J AU MCPHADEN, MJ HAYES, SP AF MCPHADEN, MJ HAYES, SP TI ON THE VARIABILITY OF WINDS, SEA-SURFACE TEMPERATURE, AND SURFACE-LAYER HEAT-CONTENT IN THE WESTERN EQUATORIAL PACIFIC SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID MIXED LAYER; SOUTHERN OSCILLATION; UPPER OCEAN; FLUX; ANOMALIES AB In this study we examine the surface layer heat balance using wind, current, and temperature data from equatorial moorings along 165-degrees-E. The analysis focuses primarily on daily to monthly time scale variations during the 1986-1987 El Nino/Southern Oscillation event. The period is one of high mean sea surface temperature (greater-than-or-similar-to 29-degrees-C) and frequent outbreaks of westerly winds. We infer that evaporative cooling related to wind speed variations accounts for a significant fraction of the observed sea surface temperature (SST) and upper ocean heat content variability. This evaporative heat flux converges nonlinearly in the surface layer, giving rise to larger temperature variations in the upper 10 m than below. Other processes examined (wind-force vertical advection and entrainment, lateral advection) were negligible or of secondary importance relative to evaporative cooling. A large fraction of the SST and surface layer heat content variance could not be directly related to wind fluctuations; this unexplained variance is probably related to shortwave radiative fluxes at the air-sea interface. RP MCPHADEN, MJ (reprint author), NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY, SEATTLE, WA 98115 USA. RI McPhaden, Michael/D-9799-2016 NR 27 TC 60 Z9 64 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 28 PY 1991 VL 96 SU S BP 3331 EP 3342 DI 10.1029/90JC01726 PG 12 WC Oceanography SC Oceanography GA FB521 UT WOS:A1991FB52100017 ER PT J AU JANOWIAK, JE ARKIN, PA AF JANOWIAK, JE ARKIN, PA TI RAINFALL VARIATIONS IN THE TROPICS DURING 1986-1989, AS ESTIMATED FROM OBSERVATIONS OF CLOUD-TOP TEMPERATURE SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article; Proceedings Paper CT WESTERN PACIFIC INTERNATIONAL MEETING AND WORKSHOP ON TOGA/COARE ( TROPICAL OCEAN GLOBAL ATMOSPHERE/COUPLED OCEAN-ATMOSPHERE RESPONSE EXPERIMENT ) CY MAY 24-30, 1989 CL CTR ORSTOM NOUMEA, NOUMEA, NEW CALEDONIA HO CTR ORSTOM NOUMEA ID SOUTHERN OSCILLATION; SCALE PRECIPITATION; OCEAN; 30-DEGREES-S; PACIFIC; CLIMATE AB Large-scale shifts in rainfall in the tropics, particularly the western tropical Pacific, were observed during the transition from "warm" (1986-1987) to "cold" (1988-1989) El Nino/Southern Oscillation (ENSO) conditions. Differences in the estimated rainfall rate in excess of 20 mm d-1 were observed south of the equator, near the international date line, between the northern winter seasons of 1986-1987 and 1988-1989. The distribution of zonal mean rainfall varied significantly during the study period, as did monthly accumulated rainfall in the global tropics, where the difference between the wettest and driest months for the period January 1986 through May 1989 was 24%. No direct measurements (rain gage, radar) of large-scale areal-averaged rainfall are available for the global tropics, hence rainfall estimates, as inferred from satellite observations of cloud-top temperature, are used in this paper. A qualitative comparison of the behavior of the rainfall estimates during the 1986-1989 period with the expected rainfall anomaly patterns in regions with known rainfall responses to both the low ("warm") and high ("cold") Southern Oscillation Index (SOI) phases of ENSO phenomena is presented. The comparison indicates that rainfall variation during 1986-1989 in these regions behaved as expected, for the most part, for both phases of the ENSO cycle. The rainfall patterns are also compared to observed moisture and vertical motion fields in the atmosphere and sea surface temperature (SST) during this period. C1 NOAA,OFF GLOBAL PROGRAMS,WASHINGTON,DC 20233. RP JANOWIAK, JE (reprint author), NOAA,NATL WEATHER SERV,NATL METEOROL CTR,CTR CLIMATE ANAL,WASHINGTON,DC 20233, USA. RI Arkin, Phillip/F-5808-2010 NR 27 TC 158 Z9 159 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 28 PY 1991 VL 96 SU S BP 3359 EP 3373 PG 15 WC Oceanography SC Oceanography GA FB521 UT WOS:A1991FB52100019 ER PT J AU BATES, JJ AF BATES, JJ TI HIGH-FREQUENCY VARIABILITY OF SPECIAL SENSOR MICROWAVE IMAGER DERIVED WIND-SPEED AND MOISTURE DURING AN INTRASEASONAL OSCILLATION SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article; Proceedings Paper CT WESTERN PACIFIC INTERNATIONAL MEETING AND WORKSHOP ON TOGA/COARE ( TROPICAL OCEAN GLOBAL ATMOSPHERE/COUPLED OCEAN-ATMOSPHERE RESPONSE EXPERIMENT ) CY MAY 24-30, 1989 CL CTR ORSTOM NOUMEA, NOUMEA, NEW CALEDONIA HO CTR ORSTOM NOUMEA ID SEA-SURFACE TEMPERATURE; EL-NINO; PACIFIC-OCEAN; HEAT; WATER; ANOMALIES; SATELLITE; CLUSTERS AB Special Sensor Microwave/Imager data are used to examine the day-to-day variability of wind speed and precipitable water during the passage of an intraseasonal oscillation. First, SSM/I precipitable water and wind speed algorithms are evaluated for the tropical western Pacific Ocean. The algorithm by Alishouse for retrieving precipitable water vapor retrieves precipitable water values that compare well with island radiosonde observations, but the wind speeds retrieved using the algorithm by Goodberlet et al. compare with buoy wind speeds only marginally. A revised wind speed algorithm, based on regression with buoy wind speeds, is derived for use in this region. During the intraseasonal oscillation, anomalously high values of precipitable water, with maximum amplitude at 10-degrees-S, accompany the movement of convection eastward. Anomalously high wind speeds are found to the west of the convection and accompany its movement east. Differences of up to 20% are found along 10-degrees-S between the means of daily latent heat flux and U+3 values and the 60-day mean of these quantities. This implies that high frequency variability must be explicitly accounted for in diagnostics and modeling of air-sea interaction in the western equatorial Pacific Ocean. RP BATES, JJ (reprint author), NOAA,ENVIRONM RES LABS,CLIMATE MONITORING & DIAGNOST LAB,325 BROADWAY,BOULDER,CO 80303, USA. RI Bates, John/D-1012-2009 OI Bates, John/0000-0002-8124-0406 NR 35 TC 14 Z9 14 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 28 PY 1991 VL 96 SU S BP 3411 EP 3423 PG 13 WC Oceanography SC Oceanography GA FB521 UT WOS:A1991FB52100023 ER PT J AU ROBERTSON, DS CARTER, WE DILLINGER, WH AF ROBERTSON, DS CARTER, WE DILLINGER, WH TI NEW MEASUREMENT OF SOLAR GRAVITATIONAL DEFLECTION OF RADIO SIGNALS USING VLBI SO NATURE LA English DT Article ID EARTHS SURFACE; INTERFEROMETRY; GRAVITY; GEODESY; 3C-273 AB RADIO observations using very-long-baseline interferometry (VLBI) can measure the deflection of electromagnetic radiation by the Sun's gravitational field with an accuracy of better than 1 milliarcsecond, and can thus be used to test General Relativity. For an object at an angle-alpha from the centre of the Sun, the expected deflection is 1 (1 + gamma) (M(s)/r(e))((1 + cos-alpha)/(1 - cos-alpha)) 1/2, where M(s) is the mass of the Sun in geometrized units 2 (1.477 x 10(5) cm), r(e) is the distance from the Earth to the Sun in cm, and gamma is a parameter whose value is 1 if General Relativity is correct but which takes on different values in other theories of gravity. For gamma = 1, the deflection is 1,750 mas at the Sun's limb, 4 mas at alpha = 90-degrees and 0 at alpha = 180-degrees. Our analysis of ten years of VLBI data, including observations of objects in the range 2.5-degrees < alpha < 178-degrees, yields an estimate gamma = 1.0002 with a formal standard error of 0.00096 and an estimated standard error of 0.002. This determination is comparable in accuracy and in good agreement with the determination from Mars-Viking time-delay measurements 3. RP ROBERTSON, DS (reprint author), NOAA,OFF OCEAN & EARTH SCI,GEOSCI LAB,ROCKVILLE,MD 20852, USA. NR 26 TC 79 Z9 80 U1 0 U2 1 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD FEB 28 PY 1991 VL 349 IS 6312 BP 768 EP 770 DI 10.1038/349768a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA EZ666 UT WOS:A1991EZ66600047 ER PT J AU JOOS, F SARMIENTO, JL SIEGENTHALER, U AF JOOS, F SARMIENTO, JL SIEGENTHALER, U TI ESTIMATES OF THE EFFECT OF SOUTHERN-OCEAN IRON FERTILIZATION ON ATMOSPHERIC CO2 CONCENTRATIONS SO NATURE LA English DT Article ID PCO2 AB IT has been suggested 1-3 that fertilizing the ocean with iron might offset the continuing increase in atmospheric CO2 by enhancing the biological uptake of carbon, thereby decreasing the surface-ocean partial pressure of CO2 and drawing down CO2 from the atmosphere. Using a box model, we present estimates of the maximum possible effect of iron fertilization, assuming that iron is continuously added to the phosphate-rich waters of the Southern Ocean, which corresponds to 16% of the world ocean surface. We find that after 100 years of fertilization, the atmospheric CO2 concentration would be 59 p.p.m. below what it would have been with no fertilization, assuming no anthropogenic CO2 emissions, and 90-107 p.p.m. less when anthropogenic emissions are included in the calculation. Such a large uptake of CO2 is unlikely to be achieved in practice, owing to a variety of constraints that require further study; the effect of iron fertilization on the ecology of the Southern Ocean also remains to be evaluated. Thus, the most effective and reliable strategy for reducing future increases in atmospheric CO2 continues to be control of anthropogenic emissions. C1 PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. RP JOOS, F (reprint author), UNIV BERN,INST PHYS,CH-3012 BERN,SWITZERLAND. OI Joos, Fortunat/0000-0002-9483-6030 NR 24 TC 76 Z9 80 U1 2 U2 20 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD FEB 28 PY 1991 VL 349 IS 6312 BP 772 EP 775 DI 10.1038/349772a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA EZ666 UT WOS:A1991EZ66600049 ER PT J AU TARLOV, MJ BOWDEN, EF AF TARLOV, MJ BOWDEN, EF TI ELECTRON-TRANSFER REACTION OF CYTOCHROME-C ADSORBED ON CARBOXYLIC-ACID TERMINATED ALKANETHIOL MONOLAYER ELECTRODES SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Note ID TRANSFER KINETICS; GOLD; REDUCTION; FILMS; DEPENDENCE; PEROXIDASE; OXIDATION; SURFACES C1 N CAROLINA STATE UNIV,DEPT CHEM,RALEIGH,NC 27695. RP TARLOV, MJ (reprint author), NATL INST STAND & TECHNOL,DIV CHEM PROC METROL,GAITHERSBURG,MD 20899, USA. NR 43 TC 332 Z9 332 U1 2 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD FEB 27 PY 1991 VL 113 IS 5 BP 1847 EP 1849 DI 10.1021/ja00005a068 PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA EZ477 UT WOS:A1991EZ47700068 ER PT J AU HRIVNAK, BJ KWOK, S AF HRIVNAK, BJ KWOK, S TI ON THE POSSIBLE BIPOLAR NATURE OF 21 MICRON IRAS SOURCES SO ASTROPHYSICAL JOURNAL LA English DT Article DE INFRARED, SOURCES; STARS, CIRCUMSTELLAR SHELLS; STARS, MASS LOSS ID PROTO-PLANETARY NEBULAE; INFRARED OBSERVATIONS; EVOLVED STARS; MASS-LOSS; EMISSION; CRL-2688; CALIBRATION; CANDIDATES; OBJECTS; EXCESS AB We report the discovery of another IRAS source (22574 + 6609) showing the unidentified 21-mu-m emission feature. Its overall energy distribution is similar to the well-known edge-on bipolar nebulae AFGL 2688 and AFGL 618. Ground-based optical and infrared observations of this object and two other 21-mu-m sources show that while all three have very similar infrared properties, they differ greatly in the visual region. We suggest that all three of these 21-mu-m sources are intrinsically similar bipolar nebulae viewed at different orientations. C1 UNIV COLORADO, NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. UNIV CALGARY, DEPT PHYS & ASTRON, CALGARY T2N 1N4, ALBERTA, CANADA. RP HRIVNAK, BJ (reprint author), VALPARAISO UNIV, DEPT PHYS, VALPARAISO, IN 46383 USA. RI Kwok, Sun/D-3080-2009 OI Kwok, Sun/0000-0001-7708-081X NR 43 TC 41 Z9 41 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 FEB 20 PY 1991 VL 368 IS 2 BP 564 EP + DI 10.1086/169720 PN 1 PG 0 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA EX185 UT WOS:A1991EX18500025 ER PT J AU REID, GC AF REID, GC TI SOLAR TOTAL IRRADIANCE VARIATIONS AND THE GLOBAL SEA-SURFACE TEMPERATURE RECORD SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AIR-TEMPERATURE; VOLCANIC-ERUPTIONS; CLIMATE CHANGE; TIME SCALES; VARIABILITY; LUMINOSITY; MODEL; ATMOSPHERE; CONSTANT; FLUCTUATIONS AB The record of globally averaged sea surface temperature (SST) over the past 130 years shows a highly significant correlation with the envelope of the 11-year cycle of solar activity over the same period. This correlation could be explained by a variation in the sun's total irradiance (the solar "constant") that is in phase with the solar-cycle envelope, supporting and updating an earlier conclusion by Eddy (1976) that such variations could have played a major role in climate change over the past millennium. Measurements of the total irradiance from spacecraft, rockets, and balloons over the past 25 years have provided evidence of long-term variations and have been used to deveop a simple linear relationship between irradiance and the envelope of the sunspot cycle. This relationship has been used to force a one-dimensional model of the thermal structure of the ocean (Hoffert et al., 1980), consisting of a 100-m mixed layer coupled to a deep ocean and including a thermohaline circulation. The model was started in the mid-seventeenth century, at the time of the Maunder Minimum of solar activity, and mixed-layer temperatures were calculated at 6-month intervals up to the present. The total range of irradiance values during the period was about 1%, and the total range of SST was about 1-degrees-C. Cool periods, when temperatures were about 0.5-degrees-C below present-day values, were found in the early decades of both the nineteenth and twentieth centuries. There is direct evidence for the latter period from the historical SST record and some indirect evidence for the earlier cool period. While many aspects of the study are unavoidably simplistic, the results can be taken as indicating that solar variability has been an important contributor to global climate variations in recent decades. It has probably not been the only contributor, however, and in particular, the growing atmospheric burden of greenhouse gases may well have played an important role in the immediate past. This role is likely to become even more important in the near future. C1 UNIV COLORADO, COOPERAT INST RES ENVIRONM, BOULDER, CO 80309 USA. RP NOAA, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. NR 67 TC 167 Z9 179 U1 1 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 20 PY 1991 VL 96 IS D2 BP 2835 EP 2844 DI 10.1029/90JD02274 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA EZ657 UT WOS:A1991EZ65700002 ER PT J AU VANZANDT, TE NASTROM, GD GREEN, JL AF VANZANDT, TE NASTROM, GD GREEN, JL TI FREQUENCY-SPECTRA OF VERTICAL VELOCITY FROM FLATLAND VHF RADAR DATA SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GRAVITY-WAVE SPECTRUM; MST RADAR; STRATOSPHERE; ATMOSPHERE AB The vertical wind velocity over very flat terrain was observed every 153 s in the troposphere and lower stratosphere by the Flatland radar, near Champaign-Urbana, Illinois. Several hundred frequency spectra were calculated from all accepted 6-hour time series from March through May 1987. By stratifying the spectra in various ways we find the following: (1) The spectra were independent of altitude within the troposphere or lower stratosphere, but the spectra in the two regions differed in amplitude and frequency; (2) At a given altitude the spectra were independent of the wind shear duBAR/dz, the buoyancy frequency N, and the maximum wind speed below 16 km; (3) The change of spectral shape and amplitude with increasing background wind speed uBAR was much less than at stations near mountains. The variance of the spectra, equal to twice the vertical kinetic energy per unit mass, roughly doubled as u-BAR increased by 10 m s-1; (4) The spectra were consistent with being due to a spectrum of gravity waves, as indicated by the sharp drop in spectral amplitude near N at small uBAR and by the fact that the observed change of shape with increasing uBAR was quite consistent with the change of shape of model Doppler-shifted gravity wave spectra; (5) The results of comparison between the observed and model spectra are consistent with an intrinsic gravity wave spectrum that is invariant with uBAR, duBAR/dz, etc., contrary to expectations from gravity wave theory; (6) The results are insensitive to the azimuthal distribution of gravity wave energy, as long as the distribution is roughly symmetrical relative to the mean flow; (7) The resulting characteristics horizontal phase velocity c* of the intrinsic frequency spectrum was about 6 m s-1 in both the troposphere and the stratosphere. The corresponding characteristic vertical wavelengths were about 3300 and 1800 m, respectively, consistent with previous estimates. C1 ST CLOUD STATE UNIV, DEPT EARTH SCI, ST CLOUD, MN 56301 USA. RP VANZANDT, TE (reprint author), NOAA, AERON LAB, MAIL CODE R-E-AL3, 325 BROADWAY, BOULDER, CO 80303 USA. NR 22 TC 29 Z9 29 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 20 PY 1991 VL 96 IS D2 BP 2845 EP 2855 DI 10.1029/90JD02220 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA EZ657 UT WOS:A1991EZ65700003 ER PT J AU MCPETERS, RD KOMHYR, WD AF MCPETERS, RD KOMHYR, WD TI LONG-TERM CHANGES IN THE TOTAL OZONE MAPPING SPECTROMETER RELATIVE TO WORLD PRIMARY STANDARD DOBSON SPECTROMETER-83 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB We have examined the stability of the calibration of the Nimbus 7 solar backscatter ultraviolet (SBUV) and total ozone mapping spectrometer (TOMS) instruments by comparing their ozone measurements with those made by a single, very stable Dobson instrument: the world primary standard Dobson spectrometer number 83. Measurements of ozone made with instrument 83 at Mauna Loa observatory in eight summers between 1979 and 1989 were compared with coincident TOMS ozone measurements. The comparison shows that relative to instrument 83, ozone measured by TOMS (and SBUV) was stable between 1979 and approximately 1983, had decreased by 3% by 1986, and had decreased by almost 7% by 1989. A similar time dependence is seen when data from an ensemble of 39 Dobson stations throughout the world is compared with TOMS over the period 1979-1987. The most likely reason for the relative drift is that the diffuser plate used by both SBUV and TOMS to measure solar flux has suffered an uncorrected wavelength dependent degradation, with most of the degradation occurring after 1983. The recently released version 6 TOMS data, corrected using the internal "pair justification" technique, show almost no drift relative to Dobson instrument 83. We conclude from these comparisons that accurate measurements of long-term global ozone change will require a coherent system incorporating both ground based and satellite based ozone measurements. C1 NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. RP MCPETERS, RD (reprint author), NASA, GODDARD SPACE FLIGHT CTR, ATMOSPHERES LAB, MAIL CODE 916, GREENBELT, MD 20771 USA. RI McPeters, Richard/G-4955-2013 OI McPeters, Richard/0000-0002-8926-8462 NR 8 TC 40 Z9 40 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 20 PY 1991 VL 96 IS D2 BP 2987 EP 2993 DI 10.1029/90JD02091 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA EZ657 UT WOS:A1991EZ65700013 ER PT J AU TRAINER, M BUHR, MP CURRAN, CM FEHSENFELD, FC HSIE, EY LIU, SC NORTON, RB PARRISH, DD WILLIAMS, EJ GANDRUD, BW RIDLEY, BA SHETTER, JD ALLWINE, EJ WESTBERG, HH AF TRAINER, M BUHR, MP CURRAN, CM FEHSENFELD, FC HSIE, EY LIU, SC NORTON, RB PARRISH, DD WILLIAMS, EJ GANDRUD, BW RIDLEY, BA SHETTER, JD ALLWINE, EJ WESTBERG, HH TI OBSERVATIONS AND MODELING OF THE REACTIVE NITROGEN PHOTOCHEMISTRY AT A RURAL SITE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GAS-PHASE REACTIONS; BIOGENIC HYDROCARBON EMISSIONS; NATURAL HYDROCARBONS; CHEMICAL MECHANISM; ORGANIC-COMPOUNDS; RADICAL REACTIONS; ALKYL NITRATES; UNITED-STATES; NIWOT RIDGE; NITRIC-ACID AB Ambient concentrations of key trace gases were measured concurrently at a rural site in the eastern United States during the summer of 1986. The extensive data set allows the evaluation of certain aspects of photochemical oxidant models. A 4-day high-pressure period is chosen for a comparison of the model predictions with observations. The emphasis of this analysis is on the discussion of the photochemistry of the reactive nitrogen species and their role in shaping the ozone budget. Observations of the NO2/NO ratio provide an estimate of the peroxy radical concentration at the site. The peroxy radical concentration so derived indicates a significant in-situ O3 formation which is in accordance with the observed diurnal variation of O3. Isoprene, a natural hydrocarbon, is shown to be much more important than the anthropogenic hydrocarbons in this O3 formation. At this rural site NO, NO2, HNO3, and peroxyacetyl nitrate (PAN) account for 85% or more of NO(y) (the sum of the reactive nitrogen species). The diurnal cycle of the reactive nitrogen species and their partitioning is determined by transport and photochemical conversion. At night in the boundary layer defined by a low-level inversion, NO(x) is the major NO(y) species at this site. Nitric acid and PAN are suppressed by dry deposition and, in the case of PAN, thermal decomposition. During the daytime the NO(x) contribution to NO(y) decreases first as higher concentrations of HNO3 and PAN are mixed downward upon the breakup of the nocturnal inversion followed by NO(x) conversion to other NO(y) species in photochemical reactions. C1 UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. NATL CTR ATMOSPHER RES, DIV ATMOSPHER CHEM, BOULDER, CO 80307 USA. WASHINGTON STATE UNIV, ATMOSPHER RES LAB, PULLMAN, WA 99164 USA. RP TRAINER, M (reprint author), NOAA, AERON LAB, ENVIRONM RES LABS, 325 BROADWAY, BOULDER, CO 80303 USA. RI Williams, Eric/F-1184-2010; Parrish, David/E-8957-2010; Trainer, Michael/H-5168-2013; Hsie, Eirh-Yu/I-4449-2013; Fehsenfeld, Frederick/I-4876-2013 OI Parrish, David/0000-0001-6312-2724; Hsie, Eirh-Yu/0000-0003-3934-9923; NR 66 TC 108 Z9 109 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 20 PY 1991 VL 96 IS D2 BP 3045 EP 3063 DI 10.1029/90JD02395 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA EZ657 UT WOS:A1991EZ65700016 ER PT J AU LYNN, JW SUMARLIN, IW NEUMANN, DA RUSH, JJ PENG, JL LI, ZY AF LYNN, JW SUMARLIN, IW NEUMANN, DA RUSH, JJ PENG, JL LI, ZY TI PHONON DENSITY OF STATES AND SUPERCONDUCTIVITY IN ND1.85CE0.15CUO4 SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCATTERING AB Inelastic-neutron-scattering techniques have been used to measure the generalized phonon density of states in superconducting Nd1.85Ce0.15CuO4. There is reasonable agreement at low energies between our measurements and recent point-contact-tunneling density-of-states measurements reported by Huang et al., which suggests that phonons play a major role in pairing in the electron-superconductor systems. The correspondence at higher energies, however, is not particularly good, but probably reflects the difficulty in obtaining quantitative tunneling data. C1 NATL INST STAND & TECHNOL,DIV REACTOR,GAITHERSBURG,MD 20899. RP LYNN, JW (reprint author), UNIV MARYLAND,CTR SUPERCONDUCTIV RES,DEPT PHYS,COLLEGE PK,MD 20742, USA. NR 20 TC 24 Z9 24 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 FEB 18 PY 1991 VL 66 IS 7 BP 919 EP 922 DI 10.1103/PhysRevLett.66.919 PG 4 WC Physics, Multidisciplinary SC Physics GA EX578 UT WOS:A1991EX57800020 ER PT J AU BRIGHT, DS NEWBURY, DE AF BRIGHT, DS NEWBURY, DE TI CONCENTRATION HISTOGRAM IMAGING - A SCATTER DIAGRAM TECHNIQUE FOR VIEWING 2 OR 3 RELATED IMAGES SO ANALYTICAL CHEMISTRY LA English DT Article ID MICROSCOPY RP BRIGHT, DS (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 10 TC 22 Z9 22 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD FEB 15 PY 1991 VL 63 IS 4 BP A243 EP & DI 10.1021/ac00004a002 PG 0 WC Chemistry, Analytical SC Chemistry GA EX235 UT WOS:A1991EX23500003 ER PT J AU DUFTY, JW MO, KC GUBBINS, KE AF DUFTY, JW MO, KC GUBBINS, KE TI MODELS FOR SELF-DIFFUSION IN THE SQUARE-WELL FLUID SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HARD-SPHERE GAS; PERTURBATION-THEORY; DYNAMICS; COEFFICIENT; EQUATION AB Transport properties of moderately dense fluids reflect several effects not present at the Boltzmann level: excluded volumes, finite collision times, and bound states. The description and relative importance of these effects is illustrated here by a discussion of the self-diffusion coefficient for the square well fluid. At high temperatures the particles behave as hard spheres and the Enskog kinetic theory describing excluded volume effects is adequate. Generalizations of the Enskog theory for application at lower temperatures are discussed critically. One approach assumes partial (uncorrelated) collisions for initial conditions modified to account for excluded volume effects. Another describes completed binary collisions at the core and edges of the well for the same modified initial conditions. Although both reduce to the Enskog theory at high temperatures, neither is adequate outside this limit for prediction of either the temperature or the density dependence. The proper treatment of both temperature and density effects is found to require a more detailed description of interrupted binary collisions and bound states. Such a treatment is described and shown to be in good agreement with computer simulation results. We conclude that generalization of the hard-sphere Enskog theory to the square well, and probably other potential models, is more subtle than might be expected and requires dynamical as well as static many-body effects. C1 NOAA,NATL WEATHER SERV,NATL METEOROL CTR,NATL WEATHER SERV,CTR CLIMATE ANAL,WASHINGTON,DC 20233. CORNELL UNIV,SCH CHEM ENGN,ITHACA,NY 14853. RP DUFTY, JW (reprint author), UNIV FLORIDA,DEPT PHYS,GAINESVILLE,FL 32611, USA. NR 29 TC 9 Z9 9 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 15 PY 1991 VL 94 IS 4 BP 3132 EP 3140 DI 10.1063/1.459783 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA EY070 UT WOS:A1991EY07000084 ER PT J AU WANNINKHOF, RH BLIVEN, LF AF WANNINKHOF, RH BLIVEN, LF TI RELATIONSHIP BETWEEN GAS-EXCHANGE, WIND-SPEED, AND RADAR BACKSCATTER IN A LARGE WIND-WAVE TANK SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID AIR-WATER-INTERFACE; CAPILLARY WAVES; SEA; MODEL; SURFACE AB Gas transfer velocities across the air-water interface are correlated with wind speed, friction velocity, and radar backscatter from the surface in a large wind-wave tank in Delft, The Netherlands. The rates of sulfur hexafluoride and nitrous oxide exchange were measured at wind speeds ranging from 3.5 m/s to 20 m/s, and with mechanically generated waves in the 100 m long, 8 m wide, and 0.7 m deep tank. Gas transfer velocities were related to wind speed with a power law dependence. Gas transfer showed a linear dependence with friction velocity. An exponential relationship between gas transfer and average radar backscatter cross section fits the wind tunnel data well for microwave units operating at 13.5 and 35 GHz in VV and HH polarization. The relative rates of gas exchange of the two gases confirm an inverse square root dependence on the Schmidt number at intermediate wind speeds. A slight enhancement of sulfur hexafluoride exchange compared to nitrous oxide exchange was evident when breaking waves were present. C1 NASA,GODDARD SPACE FLIGHT CTR,WALLOPS ISL,VA 23337. COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964. RP WANNINKHOF, RH (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LABS,DEPT OCEAN CHEM,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. RI bliven, francis/E-1450-2012 NR 40 TC 55 Z9 56 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 15 PY 1991 VL 96 IS C2 BP 2785 EP 2796 DI 10.1029/90JC02368 PG 12 WC Oceanography SC Oceanography GA EY608 UT WOS:A1991EY60800021 ER PT J AU BENDER, BA WALLACE, JS SCHRODT, DJ AF BENDER, BA WALLACE, JS SCHRODT, DJ TI EFFECT OF THERMOCHEMICAL TREATMENTS ON THE STRENGTH AND MICROSTRUCTURE OF SIC FIBERS SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID ORGANOMETALLIC POLYMER PRECURSOR; SILICON-CARBIDE FIBERS; HIGH-TENSILE STRENGTH; STRUCTURAL CHARACTERIZATION; NICALON; STABILITY AB The room-temperature strength of commercially available polymer-derived SiC fibres degrades during the typical high-temperature thermal cycle used in ceramic matrix composite fabrication. Substantial improvements in retained room-temperature strength for two different commercially available fibres were observed after annealing in carbon powder at temperatures up to 1600-degrees-C. Further improvements in strength were observed for both fibres when heat treated in CO atmospheres. X-ray diffraction, TEM, SEM, auger electron spectroscopy, and optical microscopy were used to characterize the microstructure and chemistry of these heat-treated fibres in order to understand better the degradation mechanisms of the fibres as well as their improved strength retention. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. CATALYST RES CORP,BALTIMORE,MD 21201. RP BENDER, BA (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. NR 23 TC 39 Z9 39 U1 1 U2 4 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD FEB 15 PY 1991 VL 26 IS 4 BP 970 EP 976 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA EY759 UT WOS:A1991EY75900016 ER PT J AU DAVIESJONES, R AF DAVIESJONES, R TI THE FRONTOGENETICAL FORCING OF SECONDARY CIRCULATIONS .1. THE DUALITY AND GENERALIZATION OF THE Q-VECTOR SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID OMEGA-EQUATION; DIAGNOSIS AB Hoskins, Draghici, and others have shown that the Q vector is an important quantity in quasi-geostrophic (QG) theory for the diagnosis of ageostrophic circulations. In this paper, a vorticity dynamics perspective is used to develop a generalized Q vector, Q*. An equation that relates the material derivative of the thermal-wind imbalance vector to Q* and ageostrophic terms in isentropic flow is obtained from the primitive equations (PE). The generalized Q vector is the vector mean of two terms: a frontogenetical vector that, for horizontal isentropic flow, is equal to the vector frontogenesis function F, and a vortex stretching term proportional to the stretching and reorientation of vorticity by the horizontal wind. Invoking just one QG assumption, the substitution of geostrophic for total velocity gradients, reduces Q* to Q and leads directly to the omega equation of QG theory. The frontogenetical and vortex stretching parts of the generalized Q vector of PE theory become equal in the QG limit. Thus, the conventional Q vector has dual physical interpretations in terms of vorticity and thermodynamic properties. The divergence of the Q vector in its vortex stretching form is equal to the forcing term in the Sutcliffe, Wiin-Nielsen, and Trenberth version of the omega equation. The self-destruction of balanced flow and its restoration by vertical secondary circulations is explained in terms of entropy and vorticity properties. A new assumption (Alternative Balance or AB) consists of omitting the material derivative of the thermal-wind imbalance vector, so that thermal-wind balance is restored instantaneously by secondary circulations. This approximation reduces the PE omega and secondary circulation equations to diagnostic forms resembling their QG equivalents, except for the replacement of Q by Q*. Under the AB assumption, the Q* vector points toward rising motion and inertial gravity waves are excluded. RP DAVIESJONES, R (reprint author), NOAA,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 32 TC 66 Z9 79 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD FEB 15 PY 1991 VL 48 IS 4 BP 497 EP 509 DI 10.1175/1520-0469(1991)048<0497:TFFOSC>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FC718 UT WOS:A1991FC71800001 ER PT J AU WOICIK, JC KENDELEWICZ, T MIYANO, KE BOULDIN, CE MEISSNER, PL PIANETTA, P SPICER, WE AF WOICIK, JC KENDELEWICZ, T MIYANO, KE BOULDIN, CE MEISSNER, PL PIANETTA, P SPICER, WE TI LOCAL BONDING STRUCTURE OF SB ON SI(111) BY SURFACE EXTENDED X-RAY-ABSORPTION FINE-STRUCTURE AND PHOTOEMISSION SO PHYSICAL REVIEW B LA English DT Article ID INTERFACES; SILICON; SI AB The combined techniques of surface extended x-ray-absorption fine structure (SEXAFS) and high-resolution core and valence photoelectron spectroscopy have been used to study the local bonding structure of the Sb/Si(111) interface. From photoemission, we find that the Sb atoms adsorb in a unique environment that completely saturates the dangling bonds of the Si(111) surface and that completely eliminates the surface components of the Si 2p core-level spectrum. The Sb-induced Si 2p interfacial core level is found to be shifted 0.20 +/- 0.02 eV towards higher binding energy with an intensity that corresponds to the top monolayer of surface atoms. The SEXAFS determination of the absolute surface coordination numbers and bond lengths within the first Sb shell is 2.1 +/- 0.3 Sb atoms at 2.86 +/- 0.02 angstrom and 2.0 +/- 0.4 Si atoms at 2.66 +/- 0.03 angstrom. Combined, these results indicate that Sb trimers occupy the threefold atop sites of the Si(111) surface, where each Sb atom is bonded to two Si atoms in a modified bridge configuration. C1 STANFORD UNIV,STANFORD ELECTR LABS,STANFORD,CA 94305. RP WOICIK, JC (reprint author), NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 29 TC 28 Z9 28 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 15 PY 1991 VL 43 IS 5 BP 4331 EP 4339 DI 10.1103/PhysRevB.43.4331 PG 9 WC Physics, Condensed Matter SC Physics GA EX921 UT WOS:A1991EX92100064 ER PT J AU JIA, JJ CALLCOTT, TA OBRIEN, WL DONG, QY RUBENSSON, JE MUELLER, DR EDERER, DL ROWE, JE AF JIA, JJ CALLCOTT, TA OBRIEN, WL DONG, QY RUBENSSON, JE MUELLER, DR EDERER, DL ROWE, JE TI LOCAL PARTIAL DENSITIES OF STATES IN NI AND CO SILICIDES STUDIED BY SOFT-X-RAY-EMISSION SPECTROSCOPY SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; NISI2; PHOTOEMISSION; SPECTRA; SILICON; NI2SI AB The Ni and Co monosilicides and disilicides are studied by soft-x-ray-emission spectroscopy. The Si L2,3 spectra, which provide a measure of the partial densities of states of s and d angular momentum symmetry ([s + d] PDOS) localized on the Si site, are compared with available theoretical calculations, and discussed in terms of the contribution of s electrons to the bonding. The Ni and Co M2,3 emission spectra are also obtained, and analyzed to provide information about the d PDOS localized at the metal site. These spectra are discussed in terms of p-d bonding in the silicides. C1 NATL INST STAND & TECHNOL,PHOTON PHYS GRP,GAITHERSBURG,MD 20899. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP JIA, JJ (reprint author), UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996, USA. NR 24 TC 29 Z9 29 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 15 PY 1991 VL 43 IS 6 BP 4863 EP 4870 DI 10.1103/PhysRevB.43.4863 PG 8 WC Physics, Condensed Matter SC Physics GA EY623 UT WOS:A1991EY62300036 ER PT J AU CHLEBOWSKI, T GARMANY, CD AF CHLEBOWSKI, T GARMANY, CD TI ON WINDS AND X-RAYS OF O-TYPE STARS SO ASTROPHYSICAL JOURNAL LA English DT Article DE STARS, BINARIES; STARS, EARLY-TYPE; STARS, MASS LOSS; STARS, WINDS; STARS, X-RAYS; ULTRAVIOLET, SPECTRA ID NON-LTE ANALYSIS; SPECTROSCOPIC BINARY ORBITS; EVOLVED CONTACT SYSTEMS; P-CYGNI PROFILES; SPECTRAL TYPE-O; MASS-LOSS; CARINA NEBULA; HOT STARS; STELLAR WINDS; SPACE DISTRIBUTION AB We investigate dependences between stellar wind and X-ray properties of the O-type stars. New IUE-based mass-loss rates and wind terminal velocities are obtained for 40 well-known, bright single stars or binaries. There is no evidence for enhanced mass loss from the binaries compared with the single stars. We suggest that a weak dependence between L(x) and M-upsilon-infinity found here for single stars at least partially accounts for the observed proportionality between L(x) and L(bol). Very tight, detached, massive binaries with kinetic energy of the wind exceeding 3 x 10(35) ergs s-1 (\M\ > 10(-7) M. yr-1) generate an excess X-ray flux which is in a qualitative agreement with simple theories of colliding stellar winds. C1 NATL INST STAND & TECHNOL,BOULDER,CO. UNIV COLORADO,NBS,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. NR 83 TC 182 Z9 182 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 10 PY 1991 VL 368 IS 1 BP 241 EP 251 DI 10.1086/169687 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA EU508 UT WOS:A1991EU50800023 ER PT J AU BRYAN, GL KWOK, S AF BRYAN, GL KWOK, S TI ENERGY-DISTRIBUTIONS OF SYMBIOTIC NOVAE SO ASTROPHYSICAL JOURNAL LA English DT Article DE INFRARED, SPECTRA; STARS, CIRCUMSTELLAR SHELLS; STARS, SYMBIOTIC; ULTRAVIOLET, SPECTRA ID INTERSTELLAR DUST CLOUDS; GIANT BRANCH STARS; FAR-INFRARED DATA; HM-SAGITTAE; PLANETARY-NEBULAE; ULTRAVIOLET-SPECTRUM; RADIATION TRANSPORT; MASS-LOSS; RR-TEL; EMISSION AB The IRAS low-resolution spectra of three recent symbiotic novae (HM Sge. V1016 Cyg, and RR Tel) are fitted with a dust continuum radiative transfer model. We find that the dust shells are detached from the photosphere and that the sizes of the inner radii are correlated with times since outburst. An analysis of the IUE spectra of HM Sge at different epochs suggests that the strength of the 2200 angstrom feature is decreasing with time and the grains responsible for the feature are probably formed in the white dwarf ejecta. A complete accounting of the entire energy budget from radio to X-ray shows that most of the energy is emitted by the cool component in the infrared, and a significant fraction of the flux of the hot component is escaping in the far-ultraviolet. The density-bounded nature of the circumstellar gas nebulae could be the result of a bipolar geometry of the nebulae. Unlike classical novae, the optical outburst of symbiotic novae is due to the ionization of the preexisting envelope of the cool component and is not the result of a sudden ejection by the hot component. C1 UNIV CALGARY,DEPT PHYS & ASTRON,CALGARY T2N 1N4,ALBERTA,CANADA. NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO. UNIV COLORADO,BOULDER,CO 80309. RI Kwok, Sun/D-3080-2009; OI Kwok, Sun/0000-0001-7708-081X; Bryan, Greg/0000-0003-2630-9228 NR 55 TC 16 Z9 16 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 10 PY 1991 VL 368 IS 1 BP 252 EP 260 DI 10.1086/169688 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA EU508 UT WOS:A1991EU50800024 ER PT J AU SKINNER, SL AF SKINNER, SL TI NONTHERMAL RADIO-EMISSION FROM THE X-RAY BRIGHT K5-IV STAR 1E-1751+7046 SO ASTROPHYSICAL JOURNAL LA English DT Article DE RADIATION MECHANISMS; STARS, FLARE; STARS, INDIVIDUAL (1E1751+7046); STARS, LATE-TYPE; STARS, RADIO RADIATION; STARS, X-RAYS ID MEDIUM SENSITIVITY SURVEY; FK-COMAE CANDIDATE; RS CVN BINARIES; SYSTEMS; POLARIZATION; CORONAE; DWARFS; FLARE AB I analyze VLA observations of the K5 IV star 1E 1751 + 7046, which is known to be an X-ray source on the basis of Einstein observations and which shows some similarity to stars of the FK comae type. Radio continuum emission has been detected at 3.6, 6, and 20 cm, and the spectral distribution is nearly flat. There is no evidence for circular polarization, and upper limits given. The 6 cm flux is roughly one order of magnitude less than reported in a previous VLA observation, indicating that this star may flare at radio wavelengths. The inferred radio variability and the nearly flat spectral energy distribution suggest that the emission is of nonthermal origin. A variety of possible emission mechanisms are examined, and I conclude that the emission is best explained in terms of a gyrosynchrotron/synchrotron model with the electrons following a power-law energy distribution. A brief comparison of the radio properties of 1E 1751 + 7046 with FK Comae-like stars and RS CVn systems is given. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. RP SKINNER, SL (reprint author), NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,CAMPUS BOX 440,BOULDER,CO 80309, USA. NR 40 TC 4 Z9 4 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 10 PY 1991 VL 368 IS 1 BP 272 EP 278 DI 10.1086/169691 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA EU508 UT WOS:A1991EU50800027 ER PT J AU HOLDAHL, SR DZURISIN, D AF HOLDAHL, SR DZURISIN, D TI TIME-DEPENDENT MODELS OF VERTICAL DEFORMATION FOR THE YELLOWSTONE-HEBGEN LAKE REGION, 1923-1987 SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS LA English DT Article ID NATIONAL-PARK; SURFACE DISPLACEMENTS; CRUSTAL MOVEMENTS; EARTHQUAKE; MONTANA AB Results of repeated levelings have been used to determine the patterns of elevation change associated with the Yellowstone caldera, and apparent viscoelastic rebound following the magnitude 7.3 earthquake near Hebgen Lake in 1959. Models with alternative treatments for nonuniform height change were utilized. Area-wide levelings in 1923, 1975-1977, and 1987 in Yellowstone National Park allowed derivation of uplift velocities for the periods before and after 1976. Maximum uplift velocity for the earlier period was 14 mm/yr, causing 90 cm of height change from 1923 to 1984. Recent annual levelings on the east side of the caldera show a cessation of uplift in 1984-85, and the beginning of rapid subsidence; -19 mm/yr from 1985 to 1989. The long-term uplift correlates closely with the caldera rim. After structuring the leveling observations to be insensitive to the 1959 coseismic deformation (-6 m) at Hebgen Lake, the broader spatial pattern of postseismic rebound was resolved, showing uplift of at least 32 cm. As a group, the relevelings converging at nearby West Yellowstone were accomplished at various times, which allowed selection of a best model to fit the temporal character of postseismic motion. The preferred model has a 2-year decay period indicating that uplift stopped by 1970. Supplementary indications of the uplift near Hebgen Lake were obtained by comparing Global Positioning System data to earlier levelings, facilitated by a new precise geoid by D. G. Milbert and W. T. Dewhurst (submitted manuscript, 1990). C1 US GEOL SURVEY,DAVID A JOHNSTON CASCADES VOLCANO OBSERV,VANCOUVER,WA. RP HOLDAHL, SR (reprint author), NOAA,NATL OCEAN SERV,NATL GEODET SURVEY,CHARTING & GEODET SERV,ROCKVILLE,MD 20852, USA. NR 22 TC 12 Z9 12 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-SOLID PD FEB 10 PY 1991 VL 96 IS B2 BP 2465 EP 2483 DI 10.1029/90JB02011 PG 19 WC Geosciences, Multidisciplinary SC Geology GA EX668 UT WOS:A1991EX66800036 ER PT J AU ABLE, KW FLESCHER, D AF ABLE, KW FLESCHER, D TI DISTRIBUTION AND HABITAT OF CHAIN DOGFISH, SCYLIORHINUS-RETIFER, IN THE MID-ATLANTIC BIGHT SO COPEIA LA English DT Note ID LOPHOLATILUS-CHAMAELEONTICEPS; BEHAVIOR; TILEFISH C1 NOAA,NATL MARINE FISHERIES SERV,WOODS HOLE LAB,WOODS HOLE,MA 02543. RP ABLE, KW (reprint author), RUTGERS STATE UNIV,INST MARINE & COASTAL SCI,MARINE FIELD STN,TUCKERTON,NJ 08087, USA. NR 8 TC 13 Z9 14 U1 0 U2 3 PU AMER SOC ICHTHYOLOGISTS HERPETOLOGISTS BUSINESS OFFICE PI CARBONDALE PA SOUTHERN ILLINOIS UNIV, DEPT ZOOLOGY, CARBONDALE, IL 62901-6501 SN 0045-8511 J9 COPEIA JI Copeia PD FEB 7 PY 1991 IS 1 BP 231 EP 234 PG 4 WC Zoology SC Zoology GA EY838 UT WOS:A1991EY83800029 ER PT J AU LIEBMAN, JF ROMM, MJ MEOTNER, M CYBULSKI, SM SCHEINER, S AF LIEBMAN, JF ROMM, MJ MEOTNER, M CYBULSKI, SM SCHEINER, S TI ISOTROPY IN IONIC INTERACTIONS .2. HOW SPHERICAL IS THE AMMONIUM ION - COMPARISON OF THE GAS-PHASE CLUSTERING ENERGIES AND CONDENSED-PHASE THERMOCHEMISTRY OF K+ AND NH4+ SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID MOLECULAR-ORBITAL METHODS; VALENCE BASIS-SETS; HYDROGEN-BOND; ORGANIC-MOLECULES; PROTON AFFINITY; SOLVATION; COMPLEXES; ELEMENTS; ROTATION; SYSTEMS AB High-pressure mass spectrometry is used to obtain the following clustering enthalpies and entropies of NH4+: With acetonitrile, DELTA-H-degrees (n-1,n) (kcal mol-1) n = 1, 27.6; n = 2, 21.2; n = 3, 14.2; n = 4, 11.7; and the corresponding DELTA-S-degrees (n-1,n) (cal mol-1 K-1) 24.2, 25.4, 17.5, and 22.2. With benzene, DELTA-H-degrees (n-1,n) (kcal mol-1) n = 2, 17.0; n = 3, 14.2; and the corresponding DELTA-S-degrees (n-1,n) (cal mol-1 K-1) 30.5 and 32.9. Comparison of cluster ion energies is made with the values for the corresponding species containing K+. Classical electrostatic analyses, based on "numerical experiments" and on a formal multipolar analysis, are used to probe the nature of the interactions. Morokuma and electrostatic analyses of quantum chemical calculations on K+.NH3 and NH4+.NH3 provide additional insight. Finally, documentation is given by using examples from condensed-phase media: lattice and solvation energies, crystal dynamics, conductances of electrolyte solutions, magnetic resonance measurements on NH4+ solutions, and the interactions of some key biochemical species. C1 SO ILLINOIS UNIV,DEPT CHEM & BIOCHEM,CARBONDALE,IL 62901. UNIV MARYLAND,DEPT CHEM & BIOCHEM,CATONSVILLE,MD 21228. NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899. NR 44 TC 21 Z9 21 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD FEB 7 PY 1991 VL 95 IS 3 BP 1112 EP 1119 DI 10.1021/j100156a018 PG 8 WC Chemistry, Physical SC Chemistry GA EW478 UT WOS:A1991EW47800018 ER PT J AU ERVIN, KM LINEBERGER, WC AF ERVIN, KM LINEBERGER, WC TI PHOTOELECTRON-SPECTRA OF C2- AND C2H- SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID LASER KINETIC SPECTROSCOPY; COLOR CENTER LASER; ATOMIC NEGATIVE-IONS; RADICAL V3 BAND; INFRARED-SPECTROSCOPY; ULTRAHIGH-RESOLUTION; ELECTRON-AFFINITIES; BINDING-ENERGIES; MOLECULAR ANIONS; CARBON STARS AB The photoelectron spectra of C2- and C2H- have been measured at a photon energy of 3.531 eV. The electron affinities of dicarbon, EA(C2) = 3.269 +/- 0.006 eV and ethynyl radical, EA(C2H) = 2.969 +/- 0.006 eV, are determined. The dissociation energy of dicarbon anion, D0(C2-) = 187.2 +/- 2.5 kcal mol-1, is derived from the experimental electron affinities of C2 and C and the literature value for the dissociation energy of neutral dicarbon, D0(C2) = 141.0 +/- 2.5 kcal mol-1. The CC stretch fundamental and CCH bending vibrational levels up to nu = 3 are observed in C2H(approximately X2-SIGMA+). The fundamental frequencies for C2H-(approximately X1-SIGMA+) are 1800 +/- 20 cm-1 (CC stretch) and 505 +/- 20 cm-1 (CCH bend). The photoelectron spectrum of ethynyl exhibits strong non-Franck-Condon transitions, induced by vibronic coupling, to odd vibrational levels in the CCH bend. These transitions also exhibit different photoelectron angular distributions than the Franck-Condon allowed vibrational transitions. The C2H(approximately A2-PI) excited state was not observed within the experimental energy range, implying a lower limit of 3400 cm-1 for its term energy. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,NATL INST STAND & TECHNOL,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 92 TC 128 Z9 128 U1 5 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD FEB 7 PY 1991 VL 95 IS 3 BP 1167 EP 1177 DI 10.1021/j100156a026 PG 11 WC Chemistry, Physical SC Chemistry GA EW478 UT WOS:A1991EW47800026 ER PT J AU ROSENBERG, L ZHOU, F AF ROSENBERG, L ZHOU, F TI POTENTIAL SCATTERING IN A SLOWLY VARYING LASER FIELD - RELATIVISTIC GENERALIZATIONS SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article AB A variational approach to the problem of relativistic potential scattering in a laser field is developed. The field is assumed to be slowly varying compared with the collision time and to have a well defined direction of propagation, but is otherwise arbitrary. A trial function is chosen having the correct gauge-transformation property and accounting in an approximate manner for the simultaneous interaction of the projectile with the centre of force and with the laser field. The variational calculation provides a low-frequency approximation for the transition amplitude of improved accuracy compared with those obtained in previous treatments of this problem. The analysis is first given in terms of a spin-zero wave equation and then extended to allow for the scattering of a Dirac particle. A relativistic analogue of the Kroll-Watson approximation is obtained with the field is taken to be monochromatic and certain higher-oder correction terms are dropped. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. NYU,DEPT PHYS,NEW YORK,NY 10003. RP ROSENBERG, L (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 8 TC 8 Z9 8 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD FEB 7 PY 1991 VL 24 IS 3 BP 631 EP 643 DI 10.1088/0305-4470/24/3/022 PG 13 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA EW848 UT WOS:A1991EW84800022 ER PT J AU BIRKS, JW AF BIRKS, JW TI GLOBAL AIR-POLLUTION - PROBLEMS FOR THE 1990S - BRIDGMAN,H SO NATURE LA English DT Book Review C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP BIRKS, JW (reprint author), UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RI Birks, John/H-7451-2013 OI Birks, John/0000-0003-1691-1354 NR 1 TC 0 Z9 0 U1 0 U2 0 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD FEB 7 PY 1991 VL 349 IS 6309 BP 472 EP 472 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA EW571 UT WOS:A1991EW57100048 ER PT J AU RIND, D CHIOU, EW CHU, W LARSEN, J OLTMANS, S LERNER, J MCCORMICK, MP MCMASTER, L AF RIND, D CHIOU, EW CHU, W LARSEN, J OLTMANS, S LERNER, J MCCORMICK, MP MCMASTER, L TI POSITIVE WATER-VAPOR FEEDBACK IN CLIMATE MODELS CONFIRMED BY SATELLITE DATA SO NATURE LA English DT Article AB CHIEF among the mechanisms thought to amplify the global climate response to increased concentrations of trace gases is the atmospheric water vapour feedback. As the oceans and atmosphere warm, there is increased evaporation, and it has been generally thought that the additional moisture then adds to the greenhouse effect by trapping more infrared radiation. Recently, it has been suggested that general circulation models used for evaluating climate change overestimate this response, and that increased convection in a warmer climate would actually dry the middle and upper troposphere by means of associated compensatory subsidence1. We use some new satellite-generated water vapour data to investigate this question. From a comparison of summer and winter moisture values in regions of the middle and upper troposphere that have previously been difficult to observe with confidence, we find that, as the hemispheres warm, increased convection leads to increased water vapour above 500 mbar in approximate quantitative agreement with the results from current climate models. The same conclusion is reached by comparing the tropical western and eastern Pacific regions. Thus, we conclude that the water vapour feedback is not overestimated in models and should amplify the climate response to increased trace-gas concentrations. C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. NOAA,CMDL,BOULDER,CO 80302. RP RIND, D (reprint author), NASA,GODDARD INST SPACE STUDIES,NEW YORK,NY 10025, USA. NR 10 TC 151 Z9 151 U1 0 U2 9 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD FEB 7 PY 1991 VL 349 IS 6309 BP 500 EP 503 DI 10.1038/349500a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA EW571 UT WOS:A1991EW57100057 ER PT J AU WESSMAN, CA AF WESSMAN, CA TI REMOTE-SENSING OF SOIL PROCESSES SO AGRICULTURE ECOSYSTEMS & ENVIRONMENT LA English DT Article ID LEAF REFLECTANCE; SATELLITE DATA; NITROGEN-AVAILABILITY; SPECTRAL REFLECTANCE; IMAGING SPECTROMETRY; CANOPY REFLECTANCE; VEGETATION INDEX; PHOTOSYNTHESIS; CHLOROPHYLL; TRANSPIRATION AB Estimates of ecosystem structure and function using remotely sensed data are based on the information contained in reflected and emitted radiation. Soil plays an integral role in almost all remote observations of the land surface either because the vegetation cover is discontinuous or because multiple scattering of the radiation occurs between vegetation and the underlying soil surface. However, since vegetation covers most of the land surface, we should consider the plant canopy as a primary interface to soil processes. In many ways, the canopy is an integrated expression of (and is mutually linked to) below-ground processes and can, as such, be used to infer ecosystem properties. Classifications of satellite imagery into vegetation communities in which soil processes have been characterized can be used to extrapolate those processes across the landscape based on the areal extent of the associated cover type. Ratios of reflectance values measured in the region of chlorophyll absorption to those in the highly reflected near-infrared region are sensitive to biomass quantity and, when integrated over time, strongly correlate with primary productivity. Imaging spectrometers which measure the reflected spectrum in many narrow contiguous bands enable the development of spectral mixture models to deconvolve the reflectance signal from each pixel in an image into each of the components contributed by spectrally distinct materials on the ground, e.g. vegetation and soil. High spectral resolution measurements of the absorption characteristics of major foliar chemical constituents may permit assessment of canopy-level concentrations and related processes such as decomposition and nitrogen mineralization. Predicting the types of soil processes and their rates from remote sensing data will depend on strong correlations between canopy variables and the process of interest. This paper discusses the potential for measuring canopy indicators of below-ground processes using current and emerging remote sensing technology, and how we might begin to construct a set of measurements relevant to studies of soil processes and their dynamics over time and space. Basic remote sensing principles are presented with an emphasis on the visible and short-wave infrared spectral region (0.4-2.5-mu-m), followed by a discussion of the spectral properties of soil and vegetation. RP WESSMAN, CA (reprint author), UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, CTR STUDY EARTH SPACE, BOULDER, CO 80309 USA. NR 57 TC 8 Z9 9 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8809 EI 1873-2305 J9 AGR ECOSYST ENVIRON JI Agric. Ecosyst. Environ. PD FEB PY 1991 VL 34 IS 1-4 BP 479 EP 493 DI 10.1016/0167-8809(91)90131-G PG 15 WC Agriculture, Multidisciplinary; Ecology; Environmental Sciences SC Agriculture; Environmental Sciences & Ecology GA FD132 UT WOS:A1991FD13200043 ER PT J AU CLARK, CW DEMKOY, YN AF CLARK, CW DEMKOY, YN TI MAKING ZONE PLATES WITH A LASER PRINTER SO AMERICAN JOURNAL OF PHYSICS LA English DT Article AB A simple program is presented for producing zone plates on laser printers, and some of its results and possible applications are discussed. C1 N CAROLINA STATE UNIV,DEPT PHYS,RALEIGH,NC 27695. RP CLARK, CW (reprint author), NATL INST STAND & TECHNOL,CTR ATOM MOLEC & OPT PHYS,GAITHERSBURG,MD 20899, USA. RI Clark, Charles/A-8594-2009 OI Clark, Charles/0000-0001-8724-9885 NR 13 TC 11 Z9 11 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD FEB PY 1991 VL 59 IS 2 BP 158 EP 162 DI 10.1119/1.16598 PG 5 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA EU884 UT WOS:A1991EU88400016 ER PT J AU JOHANSEN, NG BIRKS, JW AF JOHANSEN, NG BIRKS, JW TI DETERMINATION OF SULFUR-COMPOUNDS IN DIFFICULT MATRICES BY CAPILLARY COLUMN GC WITH SULFUR CHEMILUMINESCENCE DETECTION SO AMERICAN LABORATORY LA English DT Article AB Many problems are inherent in the determination of low levels of sulfur compounds. This article describes a methodology that can be used to solve many of these problems. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP JOHANSEN, NG (reprint author), SIEVERS RES INC,BOULDER,CO, USA. RI Birks, John/H-7451-2013 OI Birks, John/0000-0003-1691-1354 NR 6 TC 12 Z9 12 U1 0 U2 1 PU INT SCIENTIFIC COMMUN INC PI SHELTON PA PO BOX 870, 30 CONTROLS DRIVE, SHELTON, CT 06484-0870 SN 0044-7749 J9 AM LAB JI Am. Lab. PD FEB PY 1991 VL 23 IS 3 BP 112 EP 119 PG 8 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA EW751 UT WOS:A1991EW75100013 ER PT J AU MACKEY, EA GORDON, GE LINDSTROM, RM ANDERSON, DL AF MACKEY, EA GORDON, GE LINDSTROM, RM ANDERSON, DL TI EFFECTS OF TARGET SHAPE AND NEUTRON-SCATTERING ON ELEMENT SENSITIVITIES FOR NEUTRON-CAPTURE PROMPT GAMMA-RAY ACTIVATION-ANALYSIS SO ANALYTICAL CHEMISTRY LA English DT Article AB Results are presented for a study of the effects of neutron scattering by hydrogen on element sensitivities for in-beam neutron capture prompt gamma-ray activation analysis. In a scattering matrix, sensitivities vary as a function of both the scattering density, i.e., the number of scatterers per unit volume and the magnitude of scattering cross sections, and the target geometry, i.e., the target shape and orientation with respect to the neutron beam. Element sensitivities (counts.s-1.mg-1) increased linearly with H density (g.mL-1) for H, B, Na, Cl, K, Mn, Br, Ag, Cd, I, Sm, and Gd, measured for liquids packaged in Teflon bags. Nine of the 12 elements studied had 1.69 +/- 0.18% sensitivity enhancement per percent increase in H density. Samarium sensitivity was enhanced by only 0.54 +/- 0.07%/% H, which may indicate that neutron scattering by H causes a shift in the energy distribution of the neutrons. Manganese sensitivity was enhanced by 2.44 +/- 0.26%/% H. The enhancement of the sensitivity for H itself varied with matrix composition. For several series of disk-shaped, solid, hydrogenous targets, element sensitivities increased with decreasing target thickness until, at some limiting thickness, this trend was reversed. Consistent with theory, sensitivities measured for spherical hydrogenous targets showed no enhancement. C1 NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. US FDA,DIV CONTAMINANTS CHEM,WASHINGTON,DC 20204. RP MACKEY, EA (reprint author), UNIV MARYLAND,DEPT CHEM & BIOCHEM,COLLEGE PK,MD 20742, USA. NR 8 TC 46 Z9 46 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD FEB 1 PY 1991 VL 63 IS 3 BP 288 EP 292 DI 10.1021/ac00003a019 PG 5 WC Chemistry, Analytical SC Chemistry GA EV495 UT WOS:A1991EV49500020 PM 1824014 ER PT J AU PELLA, PA MARINENKO, RB NORRIS, JA MARLOW, A AF PELLA, PA MARINENKO, RB NORRIS, JA MARLOW, A TI APPARENT BIAS IN THE X-RAY-FLUORESCENCE DETERMINATION OF TITANIUM IN SELECTED NIST SRM LOW-ALLOY STEELS SO APPLIED SPECTROSCOPY LA English DT Article DE TITANIUM; LOW-ALLOY STEELS; X-RAY FLUORESCENCE; INCLUSIONS; ELECTRON PROBE MICROANALYSIS AB X-ray fluorescence results of the analysis of titanium in NIST SRM 1165 and 1264 low-alloy steels were found to be significantly different from the certified values. These differences appear to be unique to the XRF results since results from other methods such as emission spectroscopy did not show any discrepancies. The microhomogeneity of selected samples was examined by electron probe microanalysis and revealed the presence of titanium inclusions containing varying amounts of zirconium, niobium, and tantalum. Differences in metallurgical uniformity are believed to be the major cause of apparent XRF bias in these SRMs. XRF analysis of the new 1760-series alloys indicates that these are more uniform and more accurate for purposes of calibration than the 1160 series and 1260 series for elements such as titanium. RP PELLA, PA (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 7 TC 3 Z9 3 U1 2 U2 3 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA PO BOX 1438, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD FEB PY 1991 VL 45 IS 2 BP 242 EP 245 DI 10.1366/0003702914337614 PG 4 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA EX852 UT WOS:A1991EX85200018 ER PT J AU DUTTON, EG ENDRES, DJ AF DUTTON, EG ENDRES, DJ TI DATE OF SNOWMELT AT BARROW, ALASKA, USA SO ARCTIC AND ALPINE RESEARCH LA English DT Article ID ARCTIC TUNDRA AB The date of snowmelt near Barrow, Alaska, for recent years is determined from radiometric in situ measurements of the tundra solar albedo. The snowmelt dates determined from the albedo measurements dispute recently published values based on routine visual observations at the Barrow National Weather Service (NWS) Office. Local heat-budget-altering effects of the village and its recent abrupt growth are suggested as the cause for the disagreement between the rural albedo and NWS "in town" observations. The open tundra albedo measurements combined with hitorical NWS observations suggest that there is no significant trend in the date of snowmelt near Barrow. RP DUTTON, EG (reprint author), NOAA,ENVIRONM RES LABS,CLIMATE MONITORING & DIAGNOST LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 10 TC 21 Z9 21 U1 0 U2 0 PU INST ARCTIC ALPINE RES PI BOULDER PA UNIV COLORADO, BOULDER, CO 80309 SN 0004-0851 J9 ARCTIC ALPINE RES JI Arct. Alp. Res. PD FEB PY 1991 VL 23 IS 1 BP 115 EP 119 DI 10.2307/1551445 PG 5 WC Environmental Sciences; Geography SC Environmental Sciences & Ecology; Geography GA FB019 UT WOS:A1991FB01900016 ER PT J AU ARUOMA, OI HALLIWELL, B GAJEWSKI, E DIZDAROGLU, M AF ARUOMA, OI HALLIWELL, B GAJEWSKI, E DIZDAROGLU, M TI COPPER-ION-DEPENDENT DAMAGE TO THE BASES IN DNA IN THE PRESENCE OF HYDROGEN-PEROXIDE SO BIOCHEMICAL JOURNAL LA English DT Article ID CHROMATOGRAPHY MASS-SPECTROMETRY; AROMATIC HYDROXYLATION; DEOXYRIBONUCLEIC-ACID; SUPEROXIDE-DISMUTASE; TUMOR PROMOTION; OXYGEN RADICALS; STRAND SCISSION; IRON; ASCORBATE; COMPLEXES AB Mixtures of Cu2+ and H2O2 at pH 7.4 caused damage to the bases in DNA greater than that caused by mixtures of Fe3+ and H2O2. Addition of ascorbic acid to the Cu2+/H2O2 system caused a very large increase in base damage, much greater than that produced by the Fe3+/H2O2/ascorbic acid system. The products of base damage in the presence of Cu2+ were typical products that have been shown to result from attack of hydroxyl radicals upon the DNA bases. Cytosine glycol, thymine glycol, 8-hydroxyadenine and especially 8-hydroxyguanine were the major products in both the Cu2+/H2O2 and the Cu2+/H2O2/ascorbic acid systems. Base damage in DNA by these systems was inhibited by the chelating agents EDTA and nitrilotriacetic acid and by catalase, but not by superoxide dismutase, nor by the hydroxyl-radical scavenger mannitol. It is proposed that Cu2+ ions bound to the DNA react with H2O2 and ascorbic acid to generate hydroxyl radicals, which then immediately attack the DNA bases in a site-specific manner. A hypoxanthine/xanthine oxidase system also caused damage to the DNA bases in the presence of Cu2+ ions. This was inhibited by superoxide dismutase and catalase. The high activity of Cu2+ ions, when compared with Fe3+ ions, in causing hydroxyl-radical-dependent damage to DNA and to other biomolecules, means that the availability of Cu2+ ions in vivo must be carefully controlled. C1 NATL INST STANDARDS & TECHNOL, CTR CHEM TOXICOL, GAITHERSBURG, MD 20899 USA. RP UNIV LONDON KINGS COLL, DEPT BIOCHEM, STRAND CAMPUS, LONDON WC2R 2LS, ENGLAND. RI Halliwell, Barry/C-8318-2009 NR 50 TC 342 Z9 345 U1 2 U2 13 PU PORTLAND PRESS LTD PI LONDON PA CHARLES DARWIN HOUSE, 12 ROGER STREET, LONDON WC1N 2JU, ENGLAND SN 0264-6021 EI 1470-8728 J9 BIOCHEM J JI Biochem. J. PD FEB 1 PY 1991 VL 273 BP 601 EP 604 PN 3 PG 4 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA EY139 UT WOS:A1991EY13900016 PM 1899997 ER PT J AU WARREN, SG LONDON, J HAHN, CJ AF WARREN, SG LONDON, J HAHN, CJ TI CLOUD HOLE OVER THE UNITED-STATES SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Letter C1 UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP WARREN, SG (reprint author), UNIV WASHINGTON,DEPT ATMOSPHERE SCI AK40,SEATTLE,WA 98195, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD FEB PY 1991 VL 72 IS 2 BP 237 EP 238 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FC269 UT WOS:A1991FC26900009 ER PT J AU HAUKSSON, E GROSS, S AF HAUKSSON, E GROSS, S TI SOURCE PARAMETERS OF THE 1933 LONG-BEACH EARTHQUAKE SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID INGLEWOOD FAULT ZONE; LOS-ANGELES BASIN; CALIFORNIA EARTHQUAKES; SOUTHERN-CALIFORNIA; WRENCH TECTONICS; STRESS AB Regional seismographic network and teleseimic data for the 1933 (M(L) = 6.3) Long Beach earthquake sequence have been analyzed. Both the teleseismic focal mechanism of the main shock and the distribution of the aftershocks are consistent with the event having occurred on the Newport-Inglewood fault. The focal mechanism had a strike of 315-degrees, dip of 80-degrees to the northeast, and rake of -170-degrees. Relocation of the foreshock-main shock-aftershock sequence using modern events as fixed reference events, shows that the rupture initiated near the Huntington Beach-Newport Beach City boundary and extended unilaterally to the northwest to a distance of 13 to 16 km. The centroidal depth was 10 +/- 2 km. The total source duration was 5 sec, and the seismic moment was 5* 10(25) dyne-cm, which corresponds to an energy magnitude of M(w) = 6.4. The source radius is estimated to have been 6.6 to 7.9 km, which corresponds to a Brune stress drop of 44 to 76 bars. Both the spatial distribution of aftershocks and inversion for the source time function suggest that the earthquake may have consisted of at least two subevents. When the slip estimate from the seismic moment of 85 to 120 cm is compared with the long-term geological slip rate of 0.1 to 1.0 mm/yr along the Newport-Inglewood fault, the 1933 earthquake has a repeat time on the order of a few thousand years. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP CALTECH, DIV GEOL & PLANETARY SCI, SEISMOL LAB, PASADENA, CA 91125 USA. OI Hauksson, Egill/0000-0002-6834-5051 NR 39 TC 42 Z9 42 U1 0 U2 4 PU SEISMOLOGICAL SOC AMER PI ALBANY PA 400 EVELYN AVE, SUITE 201, ALBANY, CA 94706-1375 USA SN 0037-1106 EI 1943-3573 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD FEB PY 1991 VL 81 IS 1 BP 81 EP 98 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA EY811 UT WOS:A1991EY81100004 ER PT J AU PRINCE, E AF PRINCE, E TI HISTORY OF X-RAY CRYSTALLOGRAPHY - COMMENT SO CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS LA English DT Note C1 NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7439 J9 CHEMOMETR INTELL LAB JI Chemometrics Intell. Lab. Syst. PD FEB PY 1991 VL 10 IS 1-2 BP 19 EP 19 DI 10.1016/0169-7439(91)80030-T PG 1 WC Automation & Control Systems; Chemistry, Analytical; Computer Science, Artificial Intelligence; Instruments & Instrumentation; Mathematics, Interdisciplinary Applications; Statistics & Probability SC Automation & Control Systems; Chemistry; Computer Science; Instruments & Instrumentation; Mathematics GA FC580 UT WOS:A1991FC58000004 ER PT J AU CURRIE, LA AF CURRIE, LA TI METROLOGICAL MEASUREMENT ACCURACY - DISCUSSION SO CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS LA English DT Discussion ID PRINCIPAL COMPONENT ANALYSIS; BALANCE RECEPTOR MODEL; CURVE RESOLUTION; LEAST-SQUARES; KEY SET; SPECTRA; SYSTEM C1 NAT INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899. NR 49 TC 14 Z9 14 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7439 J9 CHEMOMETR INTELL LAB JI Chemometrics Intell. Lab. Syst. PD FEB PY 1991 VL 10 IS 1-2 BP 59 EP 67 DI 10.1016/0169-7439(91)80034-N PG 9 WC Automation & Control Systems; Chemistry, Analytical; Computer Science, Artificial Intelligence; Instruments & Instrumentation; Mathematics, Interdisciplinary Applications; Statistics & Probability SC Automation & Control Systems; Chemistry; Computer Science; Instruments & Instrumentation; Mathematics GA FC580 UT WOS:A1991FC58000008 ER PT J AU DAVIS, RW MOORE, EF ROQUEMORE, WM CHEN, LD VILIMPOC, V GOSS, LP AF DAVIS, RW MOORE, EF ROQUEMORE, WM CHEN, LD VILIMPOC, V GOSS, LP TI PRELIMINARY-RESULTS OF A NUMERICAL EXPERIMENTAL-STUDY OF THE DYNAMIC STRUCTURE OF A BUOYANT JET DIFFUSION FLAME SO COMBUSTION AND FLAME LA English DT Article ID VISUALIZATION AB Preliminary results of a joint numerical-experimental investigation of the dynamic structure of a buoyant jet diffusion flame are presented. The purpose of this effort is to determine the nature of the unsteady interactions between flames and their associated vortex motions. A direct numerical simulation of an unsteady low-speed propane-air jet diffusion flame is carried out utilizing the flame sheet and conserved variable approximations. Counterrotating vortex structures internal and external to the flame surface appear and move upward along with flame sheet bulges. Tip-cutting (flickering) occurs with a frequency of 11-15 Hz. These dynamic features bear close resemblance to those observed experimentally by means of the rective Mie scattering (RMS) technique. Comparisons between computational and experimental (determined using thin filament pyrometry) near-instantaneous radial temperature profiles at four heights in the flame also show good agreement. The assumption of zero gravity in the computation results in the complete cessation of dynamical activity, thus demonstrating the important role that buoyancy plays in the behavior of this flame. C1 WRDC,AERO PROP LAB,WRIGHT PATTERSON AFB,OH 45433. UNIV IOWA,DEPT MECH ENGN,IOWA CITY,IA 52242. SYST RES LABS INC,DAYTON,OH 45440. RP DAVIS, RW (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899, USA. NR 16 TC 65 Z9 65 U1 0 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD FEB PY 1991 VL 83 IS 3-4 BP 263 EP 270 DI 10.1016/0010-2180(91)90074-L PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA FE583 UT WOS:A1991FE58300007 ER PT J AU HEATHER, RW AF HEATHER, RW TI AN ASYMPTOTIC WAVE-FUNCTION SPLITTING PROCEDURE FOR PROPAGATING SPATIALLY EXTENDED WAVE-FUNCTIONS - APPLICATION TO INTENSE FIELD PHOTODISSSOCIATION OF H-2+ SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID DEPENDENT SCHRODINGER-EQUATION; COLLISION-INDUCED DISSOCIATION; EXCITED ELECTRONIC STATES; FOURIER METHOD SOLUTION; MULTIPHOTON IONIZATION; SPECTRAL METHOD; COLLINEAR H+H2; WAVE-FUNCTION; DYNAMICS; LASER AB We describe an efficient procedure for propagation a spatially extended wavefunction evaluated on a small grid. The procedure involves the repeated splitting of the wavefunction into a part residing mainly in the interaction region (small fragment separation) and parts residing solely in the asymptotic region (large fragment separation), and propagation each part separately. The splitting is done by multiplying the wavefunction by the functions f(R) and 1 - f(R), where R is the internuclear separation of an unbound degree of freedom and f(R) equals one in the interaction region and falls to zero in the asymptotic region. Each asymptotic piece of the wavefunction is propagated to some final time, in the momentum representation where it does not spread or translate, by a single application of a free-particle propagator. Unlike the use of an absorbing boundary, the total wavefunction can be reassembled at a later time by adding the individual asymptotic pieces, propagated to a common final time with a free-particle propagator, to the part of the wavefunction remaining in the interaction region. This procedure is well suited to propagation methods that evaluate the wavefunction on a spatial grid, because the amount of asymptotic region included in the grid, and therefore the computational effort, can be minimized (the smaller the asymptotic region, the more frequent the splitting). The propagation method is demonstrated in the calculation of the fragment kinetic energy distribution produced by the intense field photodissociation of H2+. This example illustrates the propagation method for a system whose wavefunction becomes very extended with time due to multiphoton bound-continuum and continuum-continuum transitions. RP HEATHER, RW (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 40 TC 75 Z9 75 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD FEB PY 1991 VL 63 IS 1-3 BP 446 EP 459 DI 10.1016/0010-4655(91)90269-Q PG 14 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA FF110 UT WOS:A1991FF11000039 ER PT J AU MANNING, J AF MANNING, J TI MIDDLE ATLANTIC BIGHT SALINITY - INTERANNUAL VARIABILITY SO CONTINENTAL SHELF RESEARCH LA English DT Article ID SCOTIAN SHELF; YORK BIGHT; CIRCULATION; ORIGIN; WATER; MAINE; GULF AB Twenty-eight hydrographic surveys of the Middle Atlantic Bight (MAB) were conducted during 1977-1987 as part of the National Marine Fisheries Service's Marine Resources, Monitoring, Assessment, and Prediction program. The average temperature and salinity for Shelf Water (< 34 psu) in the MAB were determined for each survey. While temperature followed a well-defined seasonal cycle, the Shelf Water salinity exhibited large interannual variations. A stepwise multiple linear regression model is used to show that variations in river discharge and in precipitation can explain 70% of the year-to-year changes in the Shelf Water salinity. RP MANNING, J (reprint author), NOAA,NMFS,NEFC,WOODS HOLE,MA 02543, USA. NR 25 TC 26 Z9 27 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD FEB PY 1991 VL 11 IS 2 BP 123 EP 137 DI 10.1016/0278-4343(91)90058-E PG 15 WC Oceanography SC Oceanography GA FD640 UT WOS:A1991FD64000002 ER PT J AU PETERSON, RL AF PETERSON, RL TI SIDELOBE SUPPRESSION IN SMALL JOSEPHSON-JUNCTIONS SO CRYOGENICS LA English DT Article DE SUPERCONDUCTIVITY; JOSEPHSON JUNCTIONS; CRITICAL CURRENT; SHAPED JUNCTIONS; DIFFRACTION PATTERNS AB Many applications of Josephson junctions require that the sidelobes of the critical-current patterns as a function of magnetic field be as small as possible. The sidelobes can be significantly suppressed by appropriate choice of junction geometry. This paper emphasizes that suppression is not just a long-junction effect. For a wide variety of shaped small junctions, the diffraction patterns are given by simple expressions, inspection of which quickly shows the overall features of the patterns. For some shapes the highest sidelobes can be kept well under 1% of the central lobe. For applications requiring long junctions, the geometry of small junctions giving the desired pattern is a practical starting point for a long-junction analysis. RP PETERSON, RL (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 11 TC 33 Z9 33 U1 0 U2 0 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD FEB PY 1991 VL 31 IS 2 BP 132 EP 135 DI 10.1016/0011-2275(91)90259-Y PG 4 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA EV053 UT WOS:A1991EV05300010 ER PT J AU GUNARATNA, PC MARINENKO, G KOCH, WF AF GUNARATNA, PC MARINENKO, G KOCH, WF TI SODIUM ACTIVITY MEASUREMENTS IN PROTEIN SOLUTIONS WITH SODIUM AMALGAM ELECTRODES SO ELECTROANALYSIS LA English DT Article ID ION-SELECTIVE ELECTRODES; POTENTIOMETRIC ANALYSIS; THERMODYNAMIC FUNCTIONS; STANDARD POTENTIALS; POTASSIUM; CHLORIDE; NA+; K+ AB A method using sodium amalgam electrodes has been developed to study the effect of protein on activity measurements and residual liquid junction potential of sodium in protein-containing solutions. It was tested for reliability by application to aqueous sodium chloride solutions before it was applied to protein-containing solutions. The experimentally determined activity coefficients are in good agreement with the activity coefficients for aqueous sodium chloride solutions reported in literature. Therefore, we used this method to measure the activity of NaCl solutions containing varying concentrations of bovine serum albumin (BSA). The electrode slope of the electrode responses in a protein-containing medium does not differ from that of pure aqueous solutions. A functional relationship has been established between the concentration of protein and the percent bias in the measurements. Measurements of electromotive force made in protein-containing solutions do not show any evidence of protein effect on liquid junction potential. C1 NATL INST STANDARDS & TECHNOL,DIV INORGAN ANALYT RES,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. NR 15 TC 0 Z9 0 U1 2 U2 2 PU VCH PUBLISHERS INC PI DEERFIELD BEACH PA 303 NW 12TH AVE, DEERFIELD BEACH, FL 33442-1788 SN 1040-0397 J9 ELECTROANAL JI Electroanalysis PD FEB PY 1991 VL 3 IS 2 BP 125 EP 129 DI 10.1002/elan.1140030209 PG 5 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA EY871 UT WOS:A1991EY87100008 ER PT J AU BAIRD, TA OLLA, BL AF BAIRD, TA OLLA, BL TI SOCIAL AND REPRODUCTIVE-BEHAVIOR OF A CAPTIVE GROUP OF WALLEYE POLLOCK, THERAGRA-CHALCOGRAMMA SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE GADIDAE; SPAWNING; SPACING; AGGREGATION AB The social and reproductive behavior of a group of four male and seven female walleye pollock, Theragra chalcogramma, were observed in a large tank. Pollock spent most of their time swimming in a loose aggregation near the surface. Males descended from the aggregation more often than females to follow and make physical contact with other males as well as with females. The difference between males and females in the frequency of diving in our tank is consistent with the reported pattern of depth segregation of the sexes in natural pollock spawning aggregations. The frequency of social interactions increased when pollock became reproductively active and was higher at night and during twilight when most of the spawning occurred. Male interactions with females most frequently involved physical contact, while male interactions with other males were more often limited to following. There was no indication that male-male interactions result in the formation of stable social dominance relationships that determine priority of access to mates, as has been suggested previously for walleye pollock. Rather, following and contact interactions appear to promote male identification of potential mates and encounters with ripe females. The possible functional significance of male social interactions is discussed in relation to reports on natural walleye pollock spawning aggregations. C1 OREGON STATE UNIV,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365. NOAA,COOPERAT INST MARINE RESOURCES STUDIES,NW & ALASKA FISHERIES CTR,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365. NR 13 TC 12 Z9 12 U1 1 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD FEB PY 1991 VL 30 IS 3 BP 295 EP 301 DI 10.1007/BF02028845 PG 7 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA EY366 UT WOS:A1991EY36600003 ER PT J AU RYER, CH OLLA, BL AF RYER, CH OLLA, BL TI INFORMATION-TRANSFER AND THE FACILITATION AND INHIBITION OF FEEDING IN A SCHOOLING FISH SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE ALARM; ATTRACTION; BEHAVIOR; CHUM SALMON; ONCORHYNCHUS-KETA; THREAT; VIGILANCE; VISUAL COMMUNICATION ID ANTI-PREDATOR STRATEGY; SHOAL SIZE; BLUNTNOSE MINNOWS; BEHAVIOR; VIGILANCE; FLOCKING; RISK; STIMULI; DOVES; BIRDS AB Recent studies show that fish forage actively when perceived risk is low, but decrease foraging and increase vigilance when perceived risk is high. Isolated juvenile chum salmon, Oncorhynchus keta, were visually exposed to groups of conspecifics engaged in different activities to examine their ability to gain information about foraging opportunity and risk by interpreting conspecific behavior. Isolates ate most when exposed to feeding groups, less when exposed to nonfeeding groups, and least when exposed to alarmed groups. Isolates exposed to alarmed conspecifics also spent more time motionless than did fish exposed to either feeding or nonfeeding conspecifics. These findings indicate that schooling fish gain information by interpreting con-specific behavior, and are consistent with research showing that animals balance the conflicting demands of foraging and vigilance. C1 NOAA,COOPERAT INST MARINE RESOURCES STUDIES,NW & ALASKA FISHERIES CTR,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365. RP RYER, CH (reprint author), OREGON STATE UNIV,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365, USA. NR 35 TC 58 Z9 59 U1 1 U2 15 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD FEB PY 1991 VL 30 IS 3 BP 317 EP 323 DI 10.1007/BF02028847 PG 7 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA EY366 UT WOS:A1991EY36600005 ER PT J AU GALT, JA LEHR, WJ PAYTON, DL AF GALT, JA LEHR, WJ PAYTON, DL TI FATE AND TRANSPORT OF THE EXXON VALDEZ OIL-SPILL .4. SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article RP GALT, JA (reprint author), NOAA,SEATTLE,WA 98115, USA. NR 9 TC 68 Z9 69 U1 1 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD FEB PY 1991 VL 25 IS 2 BP 202 EP 209 DI 10.1021/es00014a001 PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA EV665 UT WOS:A1991EV66500004 ER PT J AU MORRISON, G WARD, DK AF MORRISON, G WARD, DK TI THERMODYNAMIC PROPERTIES OF 2 ALTERNATIVE REFRIGERANTS - 1,1-DICHLORO-2,2,2-TRIFLUOROETHANE (R123) AND 1,1,1,2-TETRAFLUOROETHANE (R134A) SO FLUID PHASE EQUILIBRIA LA English DT Article ID VAPOR-PRESSURES AB This paper describes two different sets of measurements of the properties of two proposed alternative refrigerants, 1,1,1,2-tetrafluoroethane (R134a) ** and 1,1-dichloro-2,2,2-trifluoroethane (R123) **. The first are vapor-liquid equilibrium measurements made in a simple variable-volume sapphire cell. The vapor pressures and saturation liquid densities were determined for both materials, between 268 K and the critical temperature for R134a and between 303 K and 373 K for R123. The saturation vapor density was also determined for R134a from 298 K to the critical point, where the critical conditions were measured. The second set of measurements were made with a vibrating tube densimeter from the saturation pressure to 5500 kPa for R134a and to 3500 kPa for R123 in the temperature range 278 K-368 K. These data are then compared with other determinations of similar properties. C1 NATL INST STAND & TECHNOL,CTR BLDG TECHNOL,DIV BLDG ENVIRONM,GAITHERSBURG,MD 20899. RP MORRISON, G (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 22 TC 74 Z9 74 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3812 J9 FLUID PHASE EQUILIBR JI Fluid Phase Equilib. PD FEB PY 1991 VL 62 IS 1-2 BP 65 EP 86 DI 10.1016/0378-3812(91)87006-U PG 22 WC Thermodynamics; Chemistry, Physical; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA EY902 UT WOS:A1991EY90200006 ER PT J AU FARMER, GL TEGTMEYER, KJ AF FARMER, GL TEGTMEYER, KJ TI ND ISOTOPIC GRADIENTS IN UPPER CRUSTAL MAGMA CHAMBERS - EVIDENCE FOR INSITU MAGMA-WALL-ROCK INTERACTION - REPLY SO GEOLOGY LA English DT Letter C1 UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309. RP FARMER, GL (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD FEB PY 1991 VL 19 IS 2 BP 186 EP 187 PG 2 WC Geology SC Geology GA EV835 UT WOS:A1991EV83500023 ER PT J AU ROSEN, JM KJOME, NT OLTMANS, SJ AF ROSEN, JM KJOME, NT OLTMANS, SJ TI BALLOON BORNE OBSERVATIONS OF BACKSCATTER, FROST POINT AND OZONE IN POLAR STRATOSPHERIC CLOUDS AT THE SOUTH-POLE SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Concurrent backscatter and ozone measurements were made with near-simultaneous frost point soundings over the South Pole when the center of the 1990 winter vortex was at or very near that location. The initial water vapor concentration in the stratosphere was approximately 5ppmv and decreased to approximately 1.5-2.0 ppmv as cooling took place. By mid-July the stratospheric temperature had decreased to the frost point and heavy polar stratospheric cloud (PSC) activity was observed presumably due to the condensation of water vapor. The lowest water vapor concentrations observed correspond to saturated air at the lowest temperatures encountered. The slow recovery of the water vapor concentration during spring warming indicates that the 12 to 22 km altitude region in the vortex is not readily penetrated by outside air. The observed large decrease in PSC backscatter above approximately 14 km before the stratosphere began to warm is consistent with loss of particles by sedimentation leading to significant dehydration and denitrification. The region of PSC activity in July is noted to be in the same region in which ozone depletion and the persistent dehydration is observed later in the year. At the end of August heavy PSC activity was observed in the lower stratosphere and upper troposphere, consistent with earlier observations from NASA aircraft. These lower clouds were in a region that apparently was still experiencing cooling. No compelling evidence was found supporting earlier claims that PSC layers are anti-correlated with ozone inside the vortex. C1 NOAA,CMDL,BOULDER,CO 80303. RP ROSEN, JM (reprint author), UNIV WYOMING,DEPT PHYS & ASTRON,LARAMIE,WY 82071, USA. NR 7 TC 19 Z9 19 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB PY 1991 VL 18 IS 2 BP 171 EP 174 DI 10.1029/90GL02678 PG 4 WC Geosciences, Multidisciplinary SC Geology GA EY529 UT WOS:A1991EY52900014 ER PT J AU FIONDA, E FALLS, MJ WESTWATER, ER AF FIONDA, E FALLS, MJ WESTWATER, ER TI ATTENUATION STATISTICS AT 20.6, 31.65 AND 52.85 GHZ DERIVED FROM EMISSION MEASUREMENTS BY GROUND-BASED MICROWAVE RADIOMETERS SO IEE PROCEEDINGS-H MICROWAVES ANTENNAS AND PROPAGATION LA English DT Article DE RADIOWAVE PROPAGATION (MILLIMETER WAVE); SATELLITE LINKS AND SPACE COMMUNICATION ID TEMPERATURE AB Two seasons (December 1987 to February 1988 and July 1988 to September 1988) of thermal emission measurements, taken by a multi-channel ground-based microwave radiometer, are used to derive single-station zenith attenuation statistics at 20.6 and 31.65 GHz. For the summer period, statistics are also derived at 52.85 GHz. In addition, data from two radiometers located 50 km apart are used to derive two-station attenuation diversity statistics at 20.6 and 31.65 GHz. The multichannel radiometer was operated at Denver, Colorado, USA and the dual-channel device was operated at Platteville, Colorado. The diversity statistics are presented by cumulative distributions and by bivariate frequency distributions. The frequency distributions are analysed when either one or both stations have liquid clouds. C1 NOAA,ENVIRONM LABS,WAVE PROPAGAT LAB,BOULDER,CO 80303. RP FIONDA, E (reprint author), FDN UGO BORDONI,190 VIALE EUROPA,I-00144 ROME,ITALY. NR 10 TC 3 Z9 3 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0950-107X J9 IEE PROC-H PD FEB PY 1991 VL 138 IS 1 BP 46 EP 50 PG 5 WC Optics SC Optics GA EV894 UT WOS:A1991EV89400008 ER PT J AU PARAMESWARAN, M ROBINSON, AM BLACKBURN, DL GAITAN, M GEIST, J AF PARAMESWARAN, M ROBINSON, AM BLACKBURN, DL GAITAN, M GEIST, J TI MICROMACHINED THERMAL-RADIATION EMITTER FROM A COMMERCIAL CMOS PROCESS SO IEEE ELECTRON DEVICE LETTERS LA English DT Article AB Fabrication of thermally isolated micromechanical structures capable of generating thermal radiation for dynamic thermal scene simulation (DTSS) is described. Complete compatibility with a commercial CMOS process is achieved through design of a novel, but acceptable, layout for implementation by the CMOS foundry using its regular process sequence. Following commercial production and delivery of the CMOS chips, a single maskless etch in an aqueous ethylenediamine-pyrocatechol mixture (EDP) is performed to realize the micromechanical structures. The resulting structures are suspended plates consisting of polysilicon resistors encapsulated in the field and CVD oxides available in the CMOS process. The plates are suspended by aluminum heater leads that are also encapsulated in the field and CVD oxides. Studies of the suitability of these structures for DTSS have been initiated, and early favorable results are reported. C1 UNIV ALBERTA,DEPT ELECT ENGN,EDMONTON T6G 2G7,ALBERTA,CANADA. UNIV ALBERTA,ALBERTA MICROELECTR CTR,EDMONTON T6G 2G7,ALBERTA,CANADA. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP PARAMESWARAN, M (reprint author), SIMON FRASER UNIV,SCH ENGN SCI,BURNABY V5A 1S6,BC,CANADA. RI Geist, Jon/D-5386-2013 NR 7 TC 56 Z9 57 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0741-3106 J9 IEEE ELECTR DEVICE L JI IEEE Electron Device Lett. PD FEB PY 1991 VL 12 IS 2 BP 57 EP 59 DI 10.1109/55.75702 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA EU689 UT WOS:A1991EU68900008 ER PT J AU WILSON, PF MA, MT AF WILSON, PF MA, MT TI FIELDS RADIATED BY ELECTROSTATIC DISCHARGES SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article DE ELECTROSTATIC DISCHARGE; PULSED CURRENT; RADIATED ELECTRIC FIELD; RADIATED MAGNETIC FIELD; SPECTRUM; TIME-DOMAIN TECHNIQUE AB Electrostatic discharge (ESD) metrology has, to date, primarily focused on the ESD current waveforms in order to develop simulators for susceptibility testing. Significantly less attention has been given to the fields generated by an ESD event. This paper examines ESD fields both analytically and experimentally. Measurements indicate that the electric fields can be quite significant (greater-than-or-equal-to 150V /m at a distance of 1.5 m for example) for short periods of time (a few nanoseconds), particularly for relatively low-voltage events (less-than-or-equal-to 6 kV). A relatively simple dipole model of an ESD spark is developed and used to predict the radiated fields. The agreement between theory and experiment is fair. The model may be used to predict ESD fields for a wide range of possible configurations, particularly in the near-field zone where no measurements are presently available. C1 NATL INST STAND & TECHNOL,DIV ELECTROMAGNET FIELDS,BOULDER,CO 80303. RP WILSON, PF (reprint author), ASEA BROWN BOVERI CORP RES,ABB EMI CONTROL CTR,BADEN,SWITZERLAND. NR 15 TC 94 Z9 105 U1 2 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD FEB PY 1991 VL 33 IS 1 BP 10 EP 18 DI 10.1109/15.68245 PG 9 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA ET610 UT WOS:A1991ET61000002 ER PT J AU GAO, G UNLU, MS MORKOC, H BLACKBURN, DL AF GAO, G UNLU, MS MORKOC, H BLACKBURN, DL TI EMITTER BALLASTING RESISTOR DESIGN FOR, AND CURRENT HANDLING CAPABILITY OF ALGAAS/GAAS POWER HETEROJUNCTION BIPOLAR-TRANSISTORS SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article AB A systematic investigation of the emitter ballasting resistor for power Heterojunction Bipolar Transistors (HBT's) is presented. The current handling capability of power HBT's is found to improve with ballasting resistance. An equation for the optimal ballasting resistance is presented, where the effects of thermal conductivity of the substrate material and the temperature coefficient of the ballasting resistor are taken into account. Current levels of 400 to 800 mA/mm of emitter periphery at case temperatures of 25 to -80-degrees-C for power AlGaAs/GaAs HBT's have been obtained using an on-chip lightly doped GaAs emitter ballasting resistor. Device temperature has been measured using both an infrared micro-radiometer and temperature-sensitive electrical parameters. Steady-state and transient thermal modeling were also performed. Although the measured temperature is spatially nonuniform, the modeling results show that such nonuniformities would occur for a uniform current distribution, as would be expected for an HBT with emitter ballasting resistors. C1 UNIV ILLINOIS,MAT RES LAB,URBANA,IL 61801. NATL INST STAND & TECHNOL,DIV SEMICOND ELECTR,GAITHERSBURG,MD 20899. RP GAO, G (reprint author), UNIV ILLINOIS,COORDINATED SCI LAB,URBANA,IL 61801, USA. RI Unlu, Selim/B-4244-2013 NR 21 TC 70 Z9 79 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD FEB PY 1991 VL 38 IS 2 BP 185 EP 196 DI 10.1109/16.69894 PG 12 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA ET276 UT WOS:A1991ET27600001 ER PT J AU COAKLEY, KJ AF COAKLEY, KJ TI A CROSS-VALIDATION PROCEDURE FOR STOPPING THE EM ALGORITHM AND DECONVOLUTION OF NEUTRON DEPTH PROFILING SPECTRA SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article AB The iterative EM algorithm is used to deconvolve neutron depth profiling spectra. Because of statistical noise in the data, artifacts in the estimated particle emission rate profile appear after too many iterations of the EM algorithm. To avoid artifacts, the EM algorithm is stopped using a cross-validation procedure. The data are split into two independent halves. The EM algorithm is applied to one half of the data to get an estimate of the emission rates. The algorithm is stopped when the conditional likelihood of the other half of the data passes through its maximum. The roles of the two halves of the data are then switched to get a second estimate of the emission rates. The two estimates are then averaged. RP COAKLEY, KJ (reprint author), NATL INST STANDARDS & TECHNOL,DIV STAT ENGN,BLDG 101,ROOM A337,GAITHERSBURG,MD 20899, USA. NR 12 TC 27 Z9 27 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD FEB PY 1991 VL 38 IS 1 BP 9 EP 15 DI 10.1109/23.64635 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA ET829 UT WOS:A1991ET82900003 ER PT J AU VOORHEES, KJ SCHULZ, WD KUNEN, SM HENDRICKS, LJ CURRIE, LA KLOUDA, GA AF VOORHEES, KJ SCHULZ, WD KUNEN, SM HENDRICKS, LJ CURRIE, LA KLOUDA, GA TI ANALYSIS OF INSOLUBLE CARBONACEOUS MATERIALS FROM AIRBORNE PARTICLES COLLECTED IN PRISTINE REGIONS OF COLORADO SO JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS LA English DT Article DE AIRBORNE PARTICLES; ACCELERATORY MASS SPECTROMETRY; C-14 ANALYSIS; GAS CHROMATOGRAPHY; INSOLUBLE CARBONACEOUS MATERIALS; MASS SPECTROMETRY; PYROLYSIS ID ATMOSPHERIC PARTICULATE MATTER; NORTH-ATLANTIC AIR; ORGANIC-CONSTITUENTS; TREES CONTRIBUTE; NORMAL-ALKANE; TROPOSPHERE; POLLUTION; GAS; HYDROCARBONS; AEROSOLS AB Atmospheric particulate samples collected from remote mountainous locations in Colorado were extracted in sequence with methanol, methylene chloride, acetone and hexane. The resulting insoluble material was investigated using pyrolysis-mass spectrometry (Py-MS) and accelerator mass spectrometric C-14 analysis. The pyrolysis produced a complex mixture of aromatic and aliphatic hydrocarbons. The aliphatic hydrocarbons were postulated as being derived from vegetation. The C-14 analysis and the GC/MS results suggested that the aromatics occurred from combustion of living materials and also from long-range transport of industrial pollution. Appropriate samples from power plants and controlled forest fires were used to substantiate the conclusions. C1 NATL INST STAND TECHNOL, CTR ANALYT CHEM, GAITHERSBURG, MD 20899 USA. RP VOORHEES, KJ (reprint author), COLORADO SCH MINES, DEPT CHEM & GEOCHEM, GOLDEN, CO 80401 USA. NR 27 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-2370 J9 J ANAL APPL PYROL JI J. Anal. Appl. Pyrolysis PD FEB PY 1991 VL 18 IS 3-4 BP 189 EP 205 DI 10.1016/0165-2370(91)87001-3 PG 17 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA EZ798 UT WOS:A1991EZ79800001 ER PT J AU LONG, GG JEMIAN, PR WEERTMAN, JR BLACK, DR BURDETTE, HE SPAL, R AF LONG, GG JEMIAN, PR WEERTMAN, JR BLACK, DR BURDETTE, HE SPAL, R TI HIGH-RESOLUTION SMALL-ANGLE X-RAY-SCATTERING CAMERA FOR ANOMALOUS SCATTERING SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID SYNCHROTRON RADIATION; CRYSTAL MONOCHROMATORS; SYSTEMATIC METHOD; OPTICAL-SYSTEMS; PERFORMANCE; SPACE AB The design and operation of a new small-angle X-ray scattering instrument, optimized for high throughput at a synchrotron source, high angular and wave-length resolution, large sample cross-sectional area, accurate energy tunning, excellent signal-to-noise ratio and harmonic rejection are presented. The principles of design and implementation are given, as are the details of primary calibration of absolute intensity and experimental desmearing. The instrument has been tested for application to anomalous-scattering measurements near the chromium K edge. Preliminary results on samples of a heat-treated steel are presented as a demonstration of the capability of this experiment to separate the microstructure evolution as a function of temperature of a chromium-rich precipitate from the thermal behavior of other precipitates in the steel. C1 NORTHWESTERN UNIV, INST TECHNOL, EVANSTON, IL 60208 USA. RP LONG, GG (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RI Weertman, Julia/B-7540-2009; USAXS, APS/D-4198-2013 NR 22 TC 80 Z9 80 U1 1 U2 13 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 FEB 1 PY 1991 VL 24 BP 30 EP 37 DI 10.1107/S0021889890009256 PN 1 PG 8 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA EY227 UT WOS:A1991EY22700005 ER PT J AU CROSS, RW PATTON, CE SRINIVASAN, G BOOTH, JG CHEN, M AF CROSS, RW PATTON, CE SRINIVASAN, G BOOTH, JG CHEN, M TI ANOMALOUS LOW-FREQUENCY BUTTERFLY CURVES FOR SUBSIDIARY AND FERROMAGNETIC-RESONANCE OVERLAP AT 3 GHZ SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB Subsidiary absorption butterfly curves of spin-wave instability threshold versus static in-plane field have been obtained for yttrium iron garnet (YIG) thin films at 3 GHz. The butterfly curves have been found to be rather anomalous, typically displaying a pronounced dip and a very low minimum threshold. These anomalous features are attributed to the overlap of the subsidiary absorption field region with ferromagnetic resonance (FMR). First-order instability theory was extended to include the uniform mode response near FMR. The extended theory yields good fits to the data for reasonable values of the YIG FMR linewidths. The theoretical analysis also shows a predicted flip in the azimuthal propagation angle phi-k for the unstable spin waves in the region of FMR overlap. With increasing field, there are predicted discontinuous changes in rho-k from 90-degrees to 0-degrees and back to 90-degrees in the region of FMR. C1 COLORADO STATE UNIV,DEPT PHYS,FT COLLINS,CO 80523. RP CROSS, RW (reprint author), NIST,BOULDER,CO 80303, USA. NR 7 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD FEB 1 PY 1991 VL 69 IS 3 BP 1569 EP 1573 DI 10.1063/1.347251 PG 5 WC Physics, Applied SC Physics GA EW671 UT WOS:A1991EW67100069 ER PT J AU HILL, DA AF HILL, DA TI A GENERALIZATION OF THE CORNU SPIRAL FOR LOSSY MEDIA SO JOURNAL OF APPLIED PHYSICS LA English DT Note AB The classical problem of Fresnel diffraction by a straightedge is extended to allow for loss in the medium. The loss modifies the usual Cornu spiral solution because the argument of the Fresnel integral becomes complex. For high loss the contributions of the outer Fresnel zones are highly attenuated. RP HILL, DA (reprint author), NIST,INST ELECTROMAGNET FIELDS,BOULDER,CO 80303, USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD FEB 1 PY 1991 VL 69 IS 3 BP 1772 EP 1774 DI 10.1063/1.347229 PG 3 WC Physics, Applied SC Physics GA EW671 UT WOS:A1991EW67100101 ER PT J AU ZRNIC, DS AF ZRNIC, DS TI COMPLETE POLARIMETRIC AND DOPPLER MEASUREMENTS WITH A SINGLE RECEIVER RADAR SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB The concept of the polarimetric scattering matrix applicable to hydrometeors is reviewed to indicate the total number of measurands that is possible from a radar system with two orthogonal linear polarizations. It is shown how to obtain this complete set of polarimetric measurands together with Doppler spectral moments through a single receiver by proper choice of polarization in a transmit-receive sequence pair. RP ZRNIC, DS (reprint author), NOAA,NATL SEVERE STORMS LAB,ENVIRONM RES LABS,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 0 TC 11 Z9 11 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD FEB PY 1991 VL 8 IS 1 BP 159 EP 165 DI 10.1175/1520-0426(1991)008<0159:CPADMW>2.0.CO;2 PG 7 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA FC515 UT WOS:A1991FC51500014 ER PT J AU MAUL, GA BAIG, SR BUSHNELL, M AF MAUL, GA BAIG, SR BUSHNELL, M TI NOWCASTING CROSS-STREAM PROFILES OF OCEAN SURFACE CURRENT IN THE STRAITS OF FLORIDA SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Note AB Cross-stream profiles of ocean surface currents between Florida and the Bahamas are highly correlated with the cross-stream-averaged current. When the cross-stream averaged speed is high, the speed axis of the Florida Current is to the west, and when the cross-stream-averaged speed is low, the speed axis is near the center of the straits. Since sea level and weather along the Florida coast are routinely used to nowcast cross-stream-averaged speed, nowcasts of cross-stream surface current profiles and location of the speed axis can also be routinely reported. An improved algorithm using cross-stream sea level difference and local weather, and a description of the revised NOAA Gulf Stream product from the National Hurricane Center are presented. RP MAUL, GA (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. RI Maul, George/M-1629-2015 OI Maul, George/0000-0001-8413-7853 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD FEB PY 1991 VL 8 IS 1 BP 179 EP 185 DI 10.1175/1520-0426(1991)008<0179:NCSPOO>2.0.CO;2 PG 7 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA FC515 UT WOS:A1991FC51500017 ER PT J AU SUR, A FRIEDMAN, RS MILLER, PJ AF SUR, A FRIEDMAN, RS MILLER, PJ TI ROTATIONAL DEPENDENCE OF THE RYDBERG VALENCE INTERACTIONS IN THE 1-PI-G STATES OF MOLECULAR-OXYGEN SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID O2; PREDISSOCIATION; SPECTROSCOPY; D1-PI-G; O-2 AB The two-photon d 1-PI-g (upsilon') <--<-- X 3-SIGMA-g- (upsilon") transition in O2 is studied using resonance enhanced multiphoton ionization (REMPI) spectroscopy and the lowest four vibrational levels of the d 1-PI-g Rydberg state are characterized. Anomalies in the rotational constants of the Rydberg vibrational levels and perturbations in the REMPI spectra are attributed to the interaction of the Rydberg state with a bound diabatic 1-PI-g valence state. The rotational dependence of the Rydberg-valence interaction is explored by solving the coupled eigenvalue equations describing the interaction of the two states. The results from solution of the coupled equations as well as observations from photoelectron spectroscopy experiments are used to understand the additional structure seen in the REMPI spectra in the vicinity of the upsilon' = 2 Rydberg vibrational level. C1 UNIV MINNESOTA,DEPT CHEM,MINNEAPOLIS,MN 55455. HARVARD UNIV,DEPT CHEM,CAMBRIDGE,MA 02138. HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. UNIV COLORADO,NIST,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. RP SUR, A (reprint author), MT HOLYOKE COLL,DEPT CHEM,S HADLEY,MA 01075, USA. NR 13 TC 2 Z9 2 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 1 PY 1991 VL 94 IS 3 BP 1704 EP 1711 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA EV576 UT WOS:A1991EV57600005 ER PT J AU MOUNTAIN, RD HARVEY, AH AF MOUNTAIN, RD HARVEY, AH TI COMPUTER-SIMULATION OF FLUID FLUID PHASE COEXISTENCE IN MIXTURES OF NONADDITIVE SOFT DISKS SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MONTE-CARLO SIMULATION; TEMPERATURE VAPOR LINE; GIBBS ENSEMBLE; HARD-SPHERES; EQUILIBRIA AB Fluid-fluid phase equilibrium in binary mixtures of positively nonadditive soft disks is studies using both molecular dynamics and Gibbs ensemble Monte Carlo simulations. The molecular dynamics simulations are unable to provide quantitative results for the phase transition, but they do indicate that some sort of ordering takes place as the temperature is lowered. In contrast, the Gibbs ensemble simulations demonstrate unambiguously the presence of a first-order transition and give quantitative results for the coexistence curve; however, convergence is very slow for mixtures that are not symmetric. Comparison with the Gibbs ensemble results indicates that a simple first-order perturbation theory provides good results far from the consolute point. Closer to the consolute point, the theory does not reproduce the flatness of the coexistence curve; this limitation is intrinsic in any mean-field theory. Comments are made regarding the relative merits of molecular dynamics and Gibbs ensemble simulations for studying fluid-fluid phase coexistence. RP MOUNTAIN, RD (reprint author), NIST,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 22 TC 18 Z9 18 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 1 PY 1991 VL 94 IS 3 BP 2238 EP 2243 DI 10.1063/1.459894 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA EV576 UT WOS:A1991EV57600065 ER PT J AU TOMAZIC, BB MAYER, I BROWN, WE AF TOMAZIC, BB MAYER, I BROWN, WE TI ION INCORPORATION INTO OCTACALCIUM PHOSPHATE HYDROLYZATES SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID SOLUBILITY; MECHANISM; DEPOSITS AB There is considerable evidence indicating that biominerals are formed by precipitation of octacalcium phosphate followed by its hydrolysis. Therefore, the hydrolysis of octacalcium phosphate was studied in aqueous solutions of alkali nitrates/chlorides or carbonates. The hydrolysis was accompanied by incorporation of alkali and carbonate ions into apatitic hydrolysis products. These were characterized by chemical analyses, infrared and X-ray diffraction spectroscopy, and solubility measurements. The extent of hydrolysis in carbonate-free media paralleled the extent of ion incorporation: Li > Na > K. The hydrolyses in corresponding carbonate media produced less crystalline apatitic products with B-type carbonate substitution. C1 HEBREW UNIV JERUSALEM,DEPT INORGAN & ANALYT CHEM,IL-91904 JERUSALEM,ISRAEL. RP TOMAZIC, BB (reprint author), NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,PAFFENBERGER RES CTR,GAITHERSBURG,MD 20899, USA. NR 27 TC 18 Z9 18 U1 1 U2 2 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 FEB PY 1991 VL 108 IS 3-4 BP 670 EP 682 DI 10.1016/0022-0248(91)90247-3 PG 13 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA FA412 UT WOS:A1991FA41200028 ER PT J AU SIMIU, E COOK, GR AF SIMIU, E COOK, GR TI CHAOTIC MOTIONS OF SELF-EXCITED FORCED AND AUTONOMOUS SQUARE PRISMS SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article ID NUMBER AB The motion of oscillators governed by the standard equations for the aerodynamic galloping of square prisms is studied for two cases: a harmonically forced, single elastically mounted bar immersed in a uniform flow, and an autonomous, elastically coupled pair of such bars. It is shown that the behavior of the forced oscillator has similarities to the behavior of the standard circle map. Thus it is possible to describe how locked-in oscillatory forms are organized within the forcing amplitude/frequency parameter space and to identify transitions from quasiperiodicity to chaos and turbulent intermittencies. For the coupled pair of oscillators, two stable attractors were identified on which the orbits are topologically similar, respectively, to the two normal modes of the associated linear system. Depending upon the system parameters, one of the attractors contains orbits that may be periodic, quasiperiodic, or chaotic. Beyond a critical flow velocity this attractor vanishes. For the other attractor, only periodic orbits were identified. This work is the first stage of a numerical and experimental investigation aimed at assessing the potential role of chaotic dynamics in bluff body fluid elasticity, with a view to application in ocean engineering. RP SIMIU, E (reprint author), NAT INST STAND & TECH,CTR BLDG TECH,GAITHERSBURG,MD 20899, USA. NR 14 TC 7 Z9 7 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD FEB PY 1991 VL 117 IS 2 BP 241 EP 259 DI 10.1061/(ASCE)0733-9399(1991)117:2(241) PG 19 WC Engineering, Mechanical SC Engineering GA EX121 UT WOS:A1991EX12100002 ER PT J AU SCHEINFEIN, MR UNGURIS, J AESCHLIMANN, M PIERCE, DT CELOTTA, RJ AF SCHEINFEIN, MR UNGURIS, J AESCHLIMANN, M PIERCE, DT CELOTTA, RJ TI SCANNING ELECTRON-MICROSCOPY WITH POLARIZATION ANALYSIS (SEMPA) - STUDIES OF DOMAINS, DOMAIN-WALLS AND MAGNETIC SINGULARITIES AT SURFACES AND IN THIN-FILMS SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article ID FERROMAGNETIC-FILMS; DIRECT OVERWRITE; MODEL; TBFE AB Scanning Electron Microscopy with Polarization Analysis (SEMPA) is used to investigate the surface magnetic microstructure of domain walls in thin permalloy films and the domain structure of magneto-optic TbFeCo alloys. Domain wall measurements confirm the results of micromagnetic theory. RP SCHEINFEIN, MR (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RI Aeschlimann, Martin/D-7141-2011; Unguris, John/J-3989-2014 OI Aeschlimann, Martin/0000-0003-3413-5029; NR 32 TC 5 Z9 5 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD FEB PY 1991 VL 93 BP 109 EP 115 DI 10.1016/0304-8853(91)90313-Y PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA FP221 UT WOS:A1991FP22100021 ER PT J AU ZACHARIAH, MR HUZAREWICZ, S AF ZACHARIAH, MR HUZAREWICZ, S TI AEROSOL PROCESSING OF YBACUO SUPERCONDUCTORS IN A FLAME REACTOR SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB Submicron YBa2Cu3O7-delta particles have been produced in an aerosol flame reactor by a spray pyrolysis method in which an aerosol composed of an aqueous solution of Y, Ba, and Cu nitrate salts was introduced into a flame. It was observed that the configuration of the flame is particularly important for the successful application of the method. A premixed flame gave particles with an x-ray diffraction pattern resembling the XRD spectra of materials exposed to high concentrations of water vapor. An over-ventilated diffusion flame configuration produced the desired result: submicron unagglomerated, solid crystalline particles with T(c) = 92 K. RP ZACHARIAH, MR (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899, USA. NR 7 TC 46 Z9 46 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD FEB PY 1991 VL 6 IS 2 BP 264 EP 269 DI 10.1557/JMR.1991.0264 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA EW655 UT WOS:A1991EW65500007 ER PT J AU ZHANG, H KING, AH THOMSON, R AF ZHANG, H KING, AH THOMSON, R TI THE INTERACTION BETWEEN DISLOCATIONS AND INTERGRANULAR CRACKS SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID BRITTLE-FRACTURE; MOLYBDENUM; CRYSTALS; DEFORMATION; EMISSION; DUCTILE AB The elastic interactions of dislocations and intergranular cracks in isotropic materials have been studied. In the first part of the paper, a model based on the Rice-Thomson theory is established under which the conditions for dislocation emission and crack propagation can be described in terms of an emission surface, cleavage surface, and loading line in the local k-space associated with a mixed mode intergranular crack. For a given crack, the local k-field changes with the emission of dislocations from the crack tip, which alters the balance of cleavage and emission. In the second part, we present experimental results of in situ TEM observations of intergranular cracks in molybdenum. Alternating brittle crack propagation and dislocation emission is observed. The number of emitted dislocations corresponding to each crack propagation is in good agreement with the calculated values. C1 NATL INST STAND & TECHNOL,CTR MAT SCI,GAITHERSBURG,MD 20899. RP ZHANG, H (reprint author), SUNY STONY BROOK,DEPT MAT SCI & ENGN,STONY BROOK,NY 11794, USA. RI King, Alexander/B-3148-2012; King, Alexander/P-6497-2015 OI King, Alexander/0000-0001-9677-3769; King, Alexander/0000-0001-7101-6585 NR 24 TC 7 Z9 7 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD FEB PY 1991 VL 6 IS 2 BP 314 EP 323 DI 10.1557/JMR.1991.0314 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA EW655 UT WOS:A1991EW65500013 ER PT J AU ORLANDO, JJ BURKHOLDER, JB BOPEGEDERA, AMRP HOWARD, CJ AF ORLANDO, JJ BURKHOLDER, JB BOPEGEDERA, AMRP HOWARD, CJ TI INFRARED MEASUREMENTS OF BRO (X2-PI-3/2) SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID SPECTRUM; RADICALS; KINETICS; MOLECULES; PRODUCT; OZONE C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP ORLANDO, JJ (reprint author), NOAA,AERON LAB,RE AL2 325 BROADWAY,BOULDER,CO 80303, USA. RI Burkholder, James/H-4914-2013 NR 26 TC 30 Z9 30 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD FEB PY 1991 VL 145 IS 2 BP 278 EP 289 DI 10.1016/0022-2852(91)90115-Q PG 12 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA EV389 UT WOS:A1991EV38900007 ER PT J AU OHASHI, N OLSON, WB AF OHASHI, N OLSON, WB TI FOURIER-TRANSFORM SPECTRUM OF THE 2ND TORSIONAL BAND OF HYDRAZINE SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID INVERSION; STATE C1 NATL INST STAND & TECHNOL,BETHESDA,MD. RP OHASHI, N (reprint author), KANAZAWA UNIV,FAC SCI,DEPT PHYS,KANAZAWA,ISHIKAWA 920,JAPAN. NR 7 TC 11 Z9 11 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD FEB PY 1991 VL 145 IS 2 BP 383 EP 391 DI 10.1016/0022-2852(91)90125-T PG 9 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA EV389 UT WOS:A1991EV38900017 ER PT J AU WHITE, GS FREIMAN, SW WILSON, AM AF WHITE, GS FREIMAN, SW WILSON, AM TI INDENTATION DETERMINATION OF CRACK-GROWTH PARAMETERS IN GALLIUM-ARSENIDE SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article DE GALLIUM ARSENIDE; CRACKING; MECHANICAL PROPERTIES; INDENTATION; CRACK GROWTH ID FRACTURE AB Indentation measurements of the environmentally enhanced crack growth parameter, n, in GaAs have been made in water, acetonitrile, and methanol. Reasonable agreement with n values obtained from double-cantilever-beam tests was obtained. It is concluded that the range of n values which can be measured by the indentation technique is much wider than previously observed, and is strongly dependent upon the experimental configuration employed. RP WHITE, GS (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 4 TC 4 Z9 4 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD FEB PY 1991 VL 74 IS 2 BP 419 EP 421 DI 10.1111/j.1151-2916.1991.tb06898.x PG 3 WC Materials Science, Ceramics SC Materials Science GA EX751 UT WOS:A1991EX75100027 ER PT J AU NILSSON, WB GAUGLITZ, EJ HUDSON, JK AF NILSSON, WB GAUGLITZ, EJ HUDSON, JK TI SOLUBILITIES OF METHYL OLEATE, OLEIC-ACID, OLEYL GLYCEROLS, AND OLEYL GLYCEROL MIXTURES IN SUPERCRITICAL CARBON-DIOXIDE SO JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY LA English DT Article DE CARBON DIOXIDE; DIOLEYLGLYCEROL; METHYL OLEATE; MONOOLEYLGLYCEROL; OLEIC ACID; PARTITION COEFFICIENTS; SOLUBILITY; SUPERCRITICAL FLUID; TRIOLEYLGLYCEROL ID FATTY-ACIDS; FISH OIL; FLUID EXTRACTION; COMPRESSED GASES; MENHADEN OIL; ESTERS; FRACTIONATION; CO2 AB Solubility isotherms for oleic acid and methyl oleate as well as mono-, di-, and trioleylglycerol (MO, DO, and TO) in supercritical fluid CO2 at 50 and 60-degrees-C are reported. Partition coefficients for quaternary (MO-DO-TO-CO2) mixtures were obtained at 60-degrees-C at pressures ranging from 172 to 309 bar. Data indicate that diolein, and especially monoolein, exhibit positive deviation from ideal behavior, possibly due to intermolecular hydrogen bonding. Supercritical fluid CO2 appears to be a good media for removal of mono- and diacylglycerol by-products from synthetic triglyceride reaction mixtures at moderate temperatures. RP NILSSON, WB (reprint author), NOAA, NATL MARINE FISHERIES SERV, NW FISHERIES CTR, DIV UTILIZAT RES, 2725 MONTLAKE BLVD E, SEATTLE, WA 98112 USA. NR 32 TC 59 Z9 60 U1 0 U2 13 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0003-021X EI 1558-9331 J9 J AM OIL CHEM SOC JI J. Am. Oil Chem. Soc. PD FEB PY 1991 VL 68 IS 2 BP 87 EP 91 DI 10.1007/BF02662323 PG 5 WC Chemistry, Applied; Food Science & Technology SC Chemistry; Food Science & Technology GA EX540 UT WOS:A1991EX54000006 ER PT J AU STAFFORD, GR CAHEN, GL STONER, GE AF STAFFORD, GR CAHEN, GL STONER, GE TI GRAPHITE FIBER-POLYMER MATRIX COMPOSITES AS ELECTROLYSIS ELECTRODES SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID MECHANISM; REDUCTION AB The effect of electrolysis on graphite fiber-polymer matrix composites used as electrodes in a simulated seawater electrolyte was studied with interest in the impact of several composite construction variables. It was found that the electrochemical behavior is a function of the matrix polymer as well as the fiber orientation. Cathodic performance was found to be stable, while anodic performance was not. Anodic behavior was not singularly dominated by oxidation of the graphite but was affected by geometric considerations caused by the differing orientations of the fibers as well as the result of the fibers being incorporated into a polymer matrix. C1 UNIV VIRGINIA,CTR ELECTROCHEM SCI & ENGN,DEPT MAT SCI,CHARLOTTESVILLE,VA 22903. RP STAFFORD, GR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 29 TC 2 Z9 2 U1 0 U2 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD FEB PY 1991 VL 138 IS 2 BP 425 EP 430 DI 10.1149/1.2085603 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA EV776 UT WOS:A1991EV77600015 ER PT J AU PALMER, AJ AF PALMER, AJ TI RADIATION-INDUCED ORIENTATION OF ATMOSPHERIC AEROSOLS SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID ICE AB A theoretical model is presented for computing the radiation-induced orientation of nonspherical particles in the atmosphere. This process is examined as a possible remote-sensing technique for determining size and shape characteristics of atmospheric aerosols. The theoretical model is applied to cirrus particles modeled as prolate dielectric spheroids. The radiation-induced perturbations in the average tip angle of the spheroids and in the backscattered depolarization ratio are computed for an assumed radiation flux of 5 mJ/cm2 for three different wavelengths. The computed perturbations are found to be approximately 30-40 dB down from the corresponding unperturbed values and appear marginally detectable by ground-based lidars. RP PALMER, AJ (reprint author), NOAA,WAVE PROPAGAT LAB,BOULDER,CO 80303, USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD FEB PY 1991 VL 8 IS 2 BP 366 EP 369 DI 10.1364/JOSAA.8.000366 PG 4 WC Optics SC Optics GA EW646 UT WOS:A1991EW64600016 ER PT J AU FATOUROS, PP MARMAROU, A KRAFT, KA INAO, S SCHWARZ, FP AF FATOUROS, PP MARMAROU, A KRAFT, KA INAO, S SCHWARZ, FP TI INVIVO BRAIN WATER DETERMINATION BY T1 MEASUREMENTS - EFFECT OF TOTAL WATER-CONTENT, HYDRATION FRACTION, AND FIELD-STRENGTH SO MAGNETIC RESONANCE IN MEDICINE LA English DT Article ID RELAXATION-TIMES; TEMPERATURE; EDEMA C1 VIRGINIA COMMONWEALTH UNIV,MED COLL VIRGINIA,DEPT NEUROSURG,RICHMOND,VA 23298. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP FATOUROS, PP (reprint author), VIRGINIA COMMONWEALTH UNIV,MED COLL VIRGINIA,DEPT RADIOL,DIV RADIAT PHYS,BOX 72,MCV STN,RICHMOND,VA 23298, USA. FU NINDS NIH HHS [NS-12587, R01-NS-19235] NR 19 TC 83 Z9 84 U1 0 U2 2 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0740-3194 J9 MAGNET RESON MED JI Magn.Reson.Med. PD FEB PY 1991 VL 17 IS 2 BP 402 EP 413 DI 10.1002/mrm.1910170212 PG 12 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA EW712 UT WOS:A1991EW71200011 PM 2062213 ER PT J AU RUSBY, RL HUDSON, RP DURIEUX, M SCHOOLEY, JF STEUR, PPM SWENSON, CA AF RUSBY, RL HUDSON, RP DURIEUX, M SCHOOLEY, JF STEUR, PPM SWENSON, CA TI THERMODYNAMIC BASIS OF THE ITS-90 SO METROLOGIA LA English DT Article ID PLATINUM RESISTANCE THERMOMETERS; PRACTICAL TEMPERATURE SCALE; STEFAN-BOLTZMANN CONSTANT; VAPOR-PRESSURE EQUATIONS; VIRIAL-COEFFICIENTS; GAS THERMOMETRY; RADIOMETRIC DETERMINATION; FIXED-POINTS; RANGE; HELIUM AB The International Temperature Scale of 1990, ITS-90 [1], came into effect on 1 January 1990, replacing the International Practical Temperature Scale of 1968, IPTS-68 [2], and the "Echelle Provisoire de Temperature de 1976 entre 0,5 K et 30 K", EPT-76 [3]. The present paper reviews the various experimental measurements of thermodynamic temperature T (often expressed as differences (T - T68)) in the range 0,65 K to 1 357,77 K, which were available prior to September 1989, and on the basis of which values of temperature were adopted in the ITS-90. Estimates are given for the uncertainties in the derivation of these values. C1 NATL PHYS LAB,DIV QUANTUM METROL,TEDDINGTON TW11 0LW,MIDDX,ENGLAND. BUR INT POIDS & MESURES,F-92312 SEVRES,FRANCE. LEIDEN UNIV,KAMERLINGH ONNES LAB,2311 SB LEIDEN,NETHERLANDS. NATL INST STAND & TECHNOL,DIV TEMP,GAITHERSBURG,MD 20899. IST METROL G COLONNETTI,SEZ TERMOMETR,I-10135 TURIN,ITALY. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. NR 68 TC 59 Z9 59 U1 2 U2 7 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD FEB PY 1991 VL 28 IS 1 BP 9 EP 18 DI 10.1088/0026-1394/28/1/003 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA JB182 UT WOS:A1991JB18200006 ER PT J AU THOMPSON, WT BURK, SD AF THOMPSON, WT BURK, SD TI AN INVESTIGATION OF AN ARCTIC FRONT WITH A VERTICALLY NESTED MESOSCALE MODEL SO MONTHLY WEATHER REVIEW LA English DT Article ID WEATHER PREDICTION MODEL; COLD-FRONT; FRONTOGENESIS; PARAMETERIZATION; STORMS; OCEAN; LAYER; CONDENSATION; ATMOSPHERE; SIMULATION AB A vertically mesoscale regional numerical weather prediction model is used to simulate an arctic front. The front was observed during the Arctic Cyclone Expedition of 1984. The regional model employs a unique vertical nesting scheme in which the dynamics computations are performed on a low vertical-resolution (coarse) grid and the physics computations are performed on a high vertical resolution (fine) grid nested within the coarse grid. Turbulent fluxes are parameterized using a second-order closure approach. The model forecast compares favorably with the observations. Moreover, the model develops detailed mesoscale and boundary layer structure that verifies against the observations when initialized using only sparse, synoptic-scale data. A control experiment is run in which identical, high vertical resolution is used on both the dynamics and the physics grids. Several additional simulations are performed in order to demonstrate the utility and accuracy of the vertical nesting methodology. With the typical nested configuration (14 coarse grid levels, 24 fine levels), the evolution of the front is nearly identical to the control. When the resolution is degraded to 14 points on both grids, significant structural differences in the boundary layer arise. The terms of the frontogenetic forcing function are evaluated in each of the experiments. In all of the simulations, the horizontal deformation is the dominant frontogenetic effect while the tilting term is the dominant frontolytic term for this arctic front, just as it is for midlatitude cold fronts. The diabatic term is predominantly frontolytic with the strongest heating occurring in the cold air as the front moves off the ice edge and out over the Barents Sea. In an experiment in which surface sensible and latent heat fluxes are deleted, a slightly stronger front having more pronounced ageostropic circulation develops. RP NOAA, ATMOSPHER DIRECTORATE, MONTEREY, CA 93943 USA. NR 35 TC 20 Z9 20 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD FEB PY 1991 VL 119 IS 2 BP 233 EP 261 DI 10.1175/1520-0493(1991)119<0233:AIOAAF>2.0.CO;2 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FD131 UT WOS:A1991FD13100001 ER PT J AU KUO, YH SHAPIRO, MA DONALL, EG AF KUO, YH SHAPIRO, MA DONALL, EG TI THE INTERACTION BETWEEN BAROCLINIC AND DIABATIC PROCESSES IN A NUMERICAL-SIMULATION OF A RAPIDLY INTENSIFYING EXTRATROPICAL MARINE CYCLONE SO MONTHLY WEATHER REVIEW LA English DT Article ID QE-II STORM; COASTAL CYCLONE; FRONTOGENESIS; CYCLOGENESIS; EVOLUTION; SYSTEM; HEAT; JET AB This study addresses the relative contributions of adiabatic baroclinic and diabatic processes and their interaction in the evolution of a rapidly intensifying marine cyclone. Two numerical experiments were performed using a limited-area mesoscale model. The adiabatic simulation showed that the surface cyclone was associated with the quasi-geostrophic vertical motion forcing of a midtropospheric short wave for a period greater than 12 hours, suggesting the presence of deep baroclinic forcing during the evolution of the storm. The full-physics simulation produced major cyclogenesis with a central pressure of 967 mb and a deepening of 37 mb in 24 h. The model simulated the development of comma-shaped cloud patterns, which compared favorably with satellite observations of the storm. Further analysis showed that the rapid cyclogenesis was strongly related to moist frontogenesis at the warm front. During rapid storm intensification, the heavy precipitation, the generation of vorticity, strong surface frontogenesis, and large surface pressure falls all took place in the vicinity of the warm front. Quasi-geostrophic vertical velocity diagnosis of the full-physics simulation suggested a strong interaction between baroclinic and diabatic processes in the course of rapid development. The latent heat release significantly modified the frontal structure of the storm to reinforce its adiabatic secondary circulation. As a result, the adiabatic component of the vertical motion in the full-physics simulation was three times larger than that in the adiabatic simulation. Moreover, the upward and downward vertical motion induced by latent heat release was in phase with the secondary circulation associated with the adiabatic frontogenesis. The enhanced frontal circulation provided strong low-level moisture convergence to stimulate further frontal precipitation, establishing a positive feedback. Because of the large amount of latent heating associated with the warm frontal precipitation, diabatic heating was the dominant forcing mechanism for the vertical motion of the simulated storm during its rapid intensification. These results clearly indicate that it is not appropriate to treat the contribution of latent heat release (or other physical processes) to rapid development as a linear addition to the adiabatic dynamics, as has been done in most model sensitivity experiments. Rather, extratropical cyclogenesis should be viewed in the context of moist baroclinic instability with nonlinear interactions between the baroclinic dynamics and diabatic processes. C1 NOAA,WAVE PROPAGAT LAB,BOULDER,CO 80303. RP KUO, YH (reprint author), NATL CTR ATMOSPHER RES,POB 3000,BOULDER,CO 80307, USA. NR 41 TC 102 Z9 109 U1 1 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD FEB PY 1991 VL 119 IS 2 BP 368 EP 384 DI 10.1175/1520-0493(1991)119<0368:TIBBAD>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FD131 UT WOS:A1991FD13100006 ER PT J AU BOND, NA SHAPIRO, MA AF BOND, NA SHAPIRO, MA TI POLAR LOWS OVER THE GULF OF ALASKA IN CONDITIONS OF REVERSE SHEAR SO MONTHLY WEATHER REVIEW LA English DT Article ID OCEAN; DISTURBANCES; INSTABILITY; PACIFIC; CISK; FLOW AB The formation of two polar lows over the Gulf of Alaska are studied, using observations taken during the OCEAN STORMS field experiment. Synoptic-scale and mesoscale analyses were constructed using NOAA P-3 aircraft flight-level and radar data and dropwindsonde profiles, in addition to conventional data sources. The synoptic-scale analyses show that polar low development occurred in a low-level mesoscale baroclinic zone near the center of a mature, occluded synoptic-scale low pressure system. The disturbances propagated along the zone in the reverse shear sense, i.e., in the direction opposite to the thermal wind within the zone. The mesoscale analysis reveals a boundary layer jet of 38 m s-1 on the cold side of the baroclinic zone accompanying the leading polar low. Indirect evidence suggests that a Sawyer-Eliassen secondary circulation was present; polar low development occurred in the region of a frontogenetical geostrophic deformation. Convective activity was not prominent during the growth phase of the polar lows, as determined from satellite imagery and radar reflectivity measurements. Extremely high ocean waves (approximately 13 m) occurred in response to intense wind forcing on the mesoscale on a sea state preconditioned by moderate forcing on the synoptic scale. The observed synopticscale and mesoscale structures are compared with results from previously studied polar lows. This case appears to represent an example of polar low development due primarily to moist baroclinic processes. C1 NOAA, WAVE PROPAGAT LAB, BOULDER, CO 80303 USA. RP UNIV WASHINGTON, JOINT INST STUDY ATMOSPHERE & OCEAN, SEATTLE, WA 98195 USA. NR 41 TC 25 Z9 25 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD FEB PY 1991 VL 119 IS 2 BP 551 EP 572 DI 10.1175/1520-0493(1991)119<0551:PLOTGO>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA FD131 UT WOS:A1991FD13100015 ER PT J AU PAULTER, NG MAJUMDAR, AK AF PAULTER, NG MAJUMDAR, AK TI A NEW TRIPLE CORRELATOR DESIGN FOR THE MEASUREMENT OF ULTRASHORT LASER-PULSES SO OPTICS COMMUNICATIONS LA English DT Article ID OPTICAL PULSES; GENERATION; PHASE AB A measurement device, a triple correlator, is proposed for the characterization of ultrashort optical pulses. The proposed triple correlator uses two consecutive nonlinear optical interactions, a sum frequency generation followed by a difference frequency generation, to produce a triple correlation output a the same optical frequencies as the input pulse. Phase matching for the triple correlator is greatly simplified by using the given design. The operation of the triple correlator is described and examples of expected output signals are given. The reconstructed optical pulse is quite insensitive to noise, as shown by computer simulations. C1 UNIV COLORADO,DEPT ELECT ENGN,DENVER,CO 80204. RP PAULTER, NG (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET FIELDS,BOULDER,CO 80303, USA. NR 19 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD FEB 1 PY 1991 VL 81 IS 1-2 BP 95 EP 100 DI 10.1016/0030-4018(91)90302-T PG 6 WC Optics SC Optics GA EZ622 UT WOS:A1991EZ62200021 ER PT J AU GILBERT, SL AF GILBERT, SL TI FREQUENCY STABILIZATION OF A TUNABLE ERBIUM-DOPED FIBER LASER SO OPTICS LETTERS LA English DT Article ID 1.5-MU-M DFB LASER; ABSORPTION; LINE; ACETYLENE; LOCKING; DIODE; NH3; MUM AB A single-frequency Er-doped fiber laser that is tunable from 1.52 to 1.58-mu-m has been constructed. The laser linewidth was determined to be less than 1.6 MHz FWHM by observing the spectrum of the beat between the fiber laser and a 1.523-mu-m He-Ne laser. The frequency of the fiber laser was locked to several absorption lines of acetylene near 1.53-mu-m. This research demonstrates the inherent stability of fiber lasers and their potential for use in a wavelength standard for optical communications. RP GILBERT, SL (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 13 TC 40 Z9 41 U1 2 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD FEB 1 PY 1991 VL 16 IS 3 BP 150 EP 152 PG 3 WC Optics SC Optics GA EV197 UT WOS:A1991EV19700012 PM 19773865 ER PT J AU ROSENBERG, L AF ROSENBERG, L TI 2ND-ORDER CORRECTION TO THE BLOCH-NORDSIECK SUM-RULE SO PHYSICAL REVIEW A LA English DT Article ID SCATTERING; RADIATION AB As shown many years ago by Bloch and Nordsieck [Phys. Rev. 52, 54 (1937)] and Nordsieck [Phys. Rev. 52, 59 (1937)], the cross section for scattering with the emission of an arbitrary number of soft photons is finite and can be expressed in terms of the cross section for scattering absence of the radiation field. The model used by Bloch and Nordsieck included only soft-photon modes of the field, with maximum frequency omega-s. They argued that corrections to their sum rule would be expressed in terms of two small parameters, r0-omega-s/c and h-omega-s/v, where r0 is the classical electron radius and v is the scattering energy. Corrections of first order were obtained previously by the author [Phys. Rev. A 21, 1939 (1980)], in the context of a nonrelativistic formulation scattering problem. Here all corrections of second order are derived. As in the earlier versions, the corrected cross section for scattering in the radiation field, summed over final states of the field, is determined from a knowledge of the field-free cross section. Use of unitarity property (the optical theorem) is found to be a simplifying technical device for this calculation, as indicated by the cancellation of divergences in the scattering amplitude in the forward direction. It is shown that in the dipole approximation the term in the electron-field interaction that is quadratic in the vector potential, while contributing to an energy-level shift, has no effect, to second order, on the final form of the sum rule. C1 NYU,DEPT PHYS,NEW YORK,NY 10003. RP ROSENBERG, L (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD FEB 1 PY 1991 VL 43 IS 3 BP 1324 EP 1330 DI 10.1103/PhysRevA.43.1324 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA EX008 UT WOS:A1991EX00800022 ER PT J AU ZHOU, F ROSENBERG, L AF ZHOU, F ROSENBERG, L TI LOW-FREQUENCY EXPANSIONS FOR LASER-ASSISTED COLLISIONS SO PHYSICAL REVIEW A LA English DT Article ID SCATTERING; FIELD AB A variational approach to the problem of scattering in a low-frequency laser field is adopted, with trial functions chosen to be of the type originally introduced by Kroll and Watson [Phys. Rev. A 8, 804 (1973)], who used them nonvariationally. The variational calculation leads to a low-frequency approximation that includes higher-order correction terms of relatively simple form. This provides the basis for an analysis of the accuracy of the approximation as the strength of the external field varies over a wide range of values. The cross-section sum rule is shown, for the case of a linearly polarized monochromatic field of moderate intensity, to be more accurate than had previously been realized by virtue of the cancellation of higher-order correction terms in the transition amplitude. The approach is shown to be applicable to elastic and inelastic electron-atom scattering in a multimode laser field with arbitrary polarization properties; it represents a natural generalization of the standard Kohn-type variational procedure frequently employed for field-free scattering problems, reducing to it in the absence of the field. The dressing of the target by the field, an effect which is known to have a significant influence on the scattering cross section in certain circumstances, is not accounted for in the construction of the trial function, but is properly included as part of the variational correction. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. RP ZHOU, F (reprint author), NYU,DEPT PHYS,NEW YORK,NY 10003, USA. NR 10 TC 10 Z9 10 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD FEB 1 PY 1991 VL 43 IS 3 BP 1336 EP 1344 DI 10.1103/PhysRevA.43.1336 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA EX008 UT WOS:A1991EX00800024 ER PT J AU GIBBLE, KE GALLAGHER, A AF GIBBLE, KE GALLAGHER, A TI MEASUREMENTS OF VELOCITY-CHANGING COLLISION KERNELS SO PHYSICAL REVIEW A LA English DT Article ID SATURATION SPECTROSCOPY; LINE-SHAPES; LASER; SODIUM; ATOMS AB Measurements of velocity-changing collision (VCC) kernels are obtained using velocity-selective optical pumping. This is the first measurement of the shape of an elastic VCC kernel over the full thermal range of velocity changes. Since ground-state collisions are studied (5S1/2 Rb and He, Ne, Ar, Kr, or Xe), very low buffer-gas pressures can be used, and therefore pressure broadening (dephasing collisions) does not obscure the effects of VCC's. The data are deconvolved to eliminate the effects of the natural linewidth and are then extrapolated with respect to buffer-gas pressure to determine the single-collision limit. For small initial velocities, the measured kernels are consistent with a hard-sphere model for large velocity changes, but differ significantly for small velocity changes. The measured VCC kernels for large initial velocities and large velocity changes do not exhibit this agreement with the hard-sphere kernel. This implies that information about the inter-atomic potential can be obtained from a measurement of VCC kernels. We also show the inadequacy of the much-used Keilson-Storer kernel [J. Appl. Math. 10, 243 (1952)]. RP GIBBLE, KE (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 23 TC 34 Z9 34 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD FEB 1 PY 1991 VL 43 IS 3 BP 1366 EP 1380 DI 10.1103/PhysRevA.43.1366 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA EX008 UT WOS:A1991EX00800026 ER PT J AU COSTELLO, JT KENNEDY, ET SONNTAG, BF CLARK, CW AF COSTELLO, JT KENNEDY, ET SONNTAG, BF CLARK, CW TI 3P PHOTOABSORPTION OF FREE AND BOUND CR, CR+, MN, AND MN+ SO PHYSICAL REVIEW A LA English DT Article ID PHOTOIONISATION CROSS-SECTIONS; TRANSITION-METAL HALIDES; XE-LIKE IONS; ABSORPTION-SPECTROSCOPY; PHOTO-IONIZATION; ATOMIC-MN; ISOELECTRONIC SEQUENCE; ANGULAR-DISTRIBUTION; LASER EXCITATION; POSITIVE-IONS AB A dual-laser-plasma technique has been used to measure photoabsorption by atomic Cr and Mn and their ions at photon energies between 40 and 70 eV, where the dominant absorption mechanism is excitation of the 3p subshell. No dramatic differences are observed between the absorption spectra of Mn and Mn+, and these spectra are similar to those of Mn metal and MnCl2. The spectra of Cr and Cr+ are strikingly dissimilar, the mean excitation energy being about 5 eV greater in the ion. We attribute this to strong mixing of the localized 3d6 configuration with 3d5nd Rydberg configurations, an effect that is also responsible for the anomalous appearance of the Cr spectrum with respect to those of the other iron-period elements. The absorption spectra of Cr metal and CrCl2 take forms intermediate between those of Cr and Cr+. We give spectroscopic assignments to most of the sharp absorption features of Cr+ and determine the 3p ionization thresholds from quantum-defect analysis. C1 UNIV HAMBURG,INST EXPTL PHYS 2,W-2000 HAMBURG 13,GERMANY. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP COSTELLO, JT (reprint author), DUBLIN CITY UNIV,DUBLIN 9,IRELAND. RI Clark, Charles/A-8594-2009; OI Clark, Charles/0000-0001-8724-9885; Costello, John/0000-0003-4677-9999 NR 70 TC 64 Z9 64 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD FEB 1 PY 1991 VL 43 IS 3 BP 1441 EP 1450 DI 10.1103/PhysRevA.43.1441 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA EX008 UT WOS:A1991EX00800033 ER PT J AU FERNANDEZBACA, JA NICKLOW, RM TUN, Z RHYNE, JJ AF FERNANDEZBACA, JA NICKLOW, RM TUN, Z RHYNE, JJ TI NEUTRON-SCATTERING STUDY OF THE MAGNETIC EXCITATIONS OF THULIUM METAL SO PHYSICAL REVIEW B LA English DT Article AB We have performed neutron-scattering experiments to study the magnetic excitations of Tm in its low-temperature ferrimagnetic-antiphase-domain (FAD) phase. Our measurements confirm our earlier finding that the excitation spectrum of Tm in its FAD phase consists of one magnon mode with limited dispersion (8.3-9.6 meV). This result suggests that the Hamiltonian is dominated by the crystal-field-anistropy energy and that the exchange interaction is relatively weak. Two additional lower-energy excitations have also been observed, and they have been identified as originating from magnetovibrational scattering from the TA phonon. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. ATOM ENERGY CANADA LTD,CHALK RIVER NUCL LABS,CHALK RIVER K0J 1J0,ONTARIO,CANADA. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RI Fernandez-Baca, Jaime/C-3984-2014 OI Fernandez-Baca, Jaime/0000-0001-9080-5096 NR 12 TC 7 Z9 7 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1991 VL 43 IS 4 BP 3188 EP 3191 DI 10.1103/PhysRevB.43.3188 PN B PG 4 WC Physics, Condensed Matter SC Physics GA FF086 UT WOS:A1991FF08600007 ER PT J AU SCHEINFEIN, MR UNGURIS, J BLUE, JL COAKLEY, KJ PIERCE, DT CELOTTA, RJ RYAN, PJ AF SCHEINFEIN, MR UNGURIS, J BLUE, JL COAKLEY, KJ PIERCE, DT CELOTTA, RJ RYAN, PJ TI MICROMAGNETICS OF DOMAIN-WALLS AT SURFACES SO PHYSICAL REVIEW B LA English DT Article ID ELECTRON-SPIN POLARIZATION; SOFT-FERROMAGNETIC MEDIA; BLOCH-TYPE BOUNDARIES; THIN-FILM; TEMPERATURE-DEPENDENCE; LORENTZ MICROSCOPY; PERMALLOY-FILMS; IRON FILMS; MAGNETIZATION; SCATTERING AB High-spatial-resolution magnetization maps of ferromagnetic surfaces are generated with use of scanning electron microscopy with polarization analysis (SEMPA). The structure of surface Neel walls is measured by SEMPA and compared directly to the results of micromagnetics simulations. We find that the surface magnetic properties observed with SEMPA can be modeled using standard micromagnetic theory using only bulk parameters. Surface-domain-wall magnetization profiles were measured, using two different probe diameters in each case, for an Fe(100) single crystal and for Permalloy films with thicknesses of 0.12, 0.16, 0.20, and 0.24-mu-m. In making the quantitative comparison to the surface-domain-wall profiles calculated from (bulk) micromagnetic theory, the rms deviations, the chi-2 statistic, a correlation statistic, and rms deviations at 5% and 95% confidence levels were determined for each case. The calculated and measured domain wall profiles agree on the average to within +/- 7.8% for 180-degrees walls in semi-infinite crystals of Fe(100), and +/- 4.5% for 180-degrees walls in thin films of Permalloy. The micromagnetic simulations show the 180-degrees wall of the bulk turning over into a Neel wall at the surface with the magnetization in the plane of the surface. The Neel wall extends from the surface into the bulk over a depth approximately equal to a Bloch-wall width. C1 SEAGATE TECHNOL, BLOOMINGTON, MN 55435 USA. RP SCHEINFEIN, MR (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. RI Unguris, John/J-3989-2014 NR 88 TC 104 Z9 104 U1 3 U2 19 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 FEB 1 PY 1991 VL 43 IS 4 BP 3395 EP 3422 DI 10.1103/PhysRevB.43.3395 PN B PG 28 WC Physics, Condensed Matter SC Physics GA FF086 UT WOS:A1991FF08600035 ER PT J AU SU, DH COLLICA, LA AF SU, DH COLLICA, LA TI ISDN CONFORMANCE TESTING SO PROCEEDINGS OF THE IEEE LA English DT Article AB This paper is intended to provide a general understanding of theory, practice, and standardization activities of conformance testing of the protocols for the integrated services digital network (ISDN). Basic concepts of testing, development of test suits and test tools, descriptions of testing operations of major vendors, as well as recommendations for future activites, are presented to provide the reader with an broad overview of conformance testing efforts. This paper is not intended to be an in-depth study of all testing laboratories or activities for ISDN conformance testing. RP SU, DH (reprint author), NATL INST STAND & TECHNOL,NATL COMP SYST LAB,GAITHERSBURG,MD 20899, USA. NR 33 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9219 J9 P IEEE JI Proc. IEEE PD FEB PY 1991 VL 79 IS 2 BP 190 EP 198 DI 10.1109/5.64406 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA EZ190 UT WOS:A1991EZ19000009 ER PT J AU WAKID, SA ROBERTS, K AF WAKID, SA ROBERTS, K TI APPLICATION PROFILE FOR ISDN SO PROCEEDINGS OF THE IEEE LA English DT Article AB This paper emphasizes some key data processing applications to be used in conjunction with the voice and facsimile services as a platform for deploying ISDN in North America. Special emphasis is placed on the emerging standards of both Accredited Standards Committees (ASC) T1 and X3 in an attempt to harmonize the computer and telecommunication industries towards providing the user with an integrated platform that is vendor transparent and ubiquitous. This generic platform, which spans a large spector of businesses, is only presented as a base context for defining user specific needs and incubating the applications that directly relate to businesses. Distributed Transaction Processing, Electronic Data Interchange, Information Retrieval, Electronic Mail, and File Transfer together with seven supplementary services for voice and G4 facsimile are proposed for ISDN deployment in the marketplace. This paper, therefore, describes how the relevant standards may be exercised via the various ISDN channels and emphasizes the value of the North American ISDN Users' Forum for commercializing this platform. RP WAKID, SA (reprint author), NATL INST STAND & TECHNOL,DIV ADV SYST,GAITHERSBURG,MD 20899, USA. NR 36 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9219 J9 P IEEE JI Proc. IEEE PD FEB PY 1991 VL 79 IS 2 BP 199 EP 204 DI 10.1109/5.64407 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA EZ190 UT WOS:A1991EZ19000010 ER PT J AU GUTMAN, GG AF GUTMAN, GG TI VEGETATION INDEXES FROM AVHRR - AN UPDATE AND FUTURE-PROSPECTS SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID SOLAR ZENITH ANGLE; INDEX GVI DATA; NOAA-AVHRR; CALIBRATION AB Procedures that are currently applied to data from Advanced Very High Resolution Radiometer (AVHRR) in deriving vegetation indices are analyzed. It is shown that the type of compositing used has a great impact on the final product. Some misconceptions concerning the global vegetation index (GVI) data set are discussed. Cloud-screened daily data over Kansas prairie during 1 month were used to develop a viewing angle correction for the observed range of sun angles and for that particular surface type. This example indicates that the variability in the calculated vegetation indices could be reduced, thus raising the confidence level in statistical comparisons of observations for different years. The correction developed is applied to a different crop area and improvement in the results is demonstrated. Errors in the calculations are analyzed. Prospects for future improvements in processing vegetation index data are discussed. RP GUTMAN, GG (reprint author), NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,ERA12,WORLD WEATHER BLDG 718,WASHINGTON,DC 20233, USA. NR 27 TC 188 Z9 209 U1 4 U2 11 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD FEB-MAR PY 1991 VL 35 IS 2-3 BP 121 EP 136 DI 10.1016/0034-4257(91)90005-Q PG 16 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA FR683 UT WOS:A1991FR68300005 ER PT J AU MAYER, R AF MAYER, R TI DIRECT IMAGING OF X-RAYS WITH A CCD USING HARDWARE PROCESSING SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID POSITION-SENSITIVE DETECTOR; STANDARD TV RATE; COUPLED-DEVICE; ROOM-TEMPERATURE; PERFORMANCE; RADIATION; SPECTROSCOPY AB This study investigated the direct imaging of low intensity x-rays by a room-temperature charge coupled device (CCD). Commercial CCD evaluation kits read out the information and provided initial processing of the data. The extraction of the signal from noise was achieved using NIM modules rather than by storing and numerically analyzing the data. Due to the fast processing at standard TV rates, the storage of the data required conversion of the signal from a timing to a pulse height analysis (PHA) spectrum. The tested CCDs were found to have lower efficiency relative to the proportional counter for the range of photon energies (1.5-8.0 keV) studied but had higher spatial resolution than gas-filled position-sensitive detectors. Application of CCDs for x-ray energy dispersive detectors is described. RP MAYER, R (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 20 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1991 VL 62 IS 2 BP 360 EP 363 DI 10.1063/1.1142128 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA EW414 UT WOS:A1991EW41400012 ER PT J AU BERG, RF DELUCA, NP AF BERG, RF DELUCA, NP TI MILLIWATT MIXER FOR SMALL FLUID SAMPLES SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB Mixing without excessive heating is sometimes needed for temperature-sensitive fluids. We modified an inexpensive low-frequency electronic filter based on a mechanical resonator to produce a compact (16 mm) and low-power (1-3 mW) mixer for low viscosity fluids. Tests made in air and methanol at room temperature and in fluoroform near its critical point are compared against the predictions of an electromechanical model. RP BERG, RF (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1991 VL 62 IS 2 BP 527 EP 529 DI 10.1063/1.1142098 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA EW414 UT WOS:A1991EW41400037 ER PT J AU SMITH, Z DRYER, M AF SMITH, Z DRYER, M TI NUMERICAL SIMULATIONS OF HIGH-SPEED SOLAR-WIND STREAMS WITHIN 1-AU AND THEIR SIGNATURES AT 1-AU SO SOLAR PHYSICS LA English DT Article ID MOMENTUM FLUX-DENSITY; DISTURBANCES; TEMPERATURE; WAVES; MODEL; PLANE AB A parametric study of the evolution within, and signatures at, 1 AU of high-speed streams is performed with the use of a MHD, 2 1/2-D, time-dependent model. This study is an extension of an earlier one by Smith and Dryer (1990) who examined the ecliptic plane consequences of relatively short-duration, energetic solar disturbances. The present study examines both the erupting and corotating parts of long-duration, high-speed streams characteristic of coronal hole flows. By examining the variation of the simulated plasma velocity, density, temperature, and magnetic field at 1 AU, as well as the location of the solar coronal hole sources relative to the observer at 1 AU, we are able to provide some insight into the identification of the solar sources of interplanetary disturbances. We present and discuss two definitions for angle locating the solar source of interplanetary disturbances at 1 AU. We apply our results to the suggestion by Hewish (1988) that low-latitude coronal holes are suitably positioned to be the sources of major geomagnetic storms when the holes are in the eastern half of the solar hemisphere at the time of the commencement of the storm. Our results indicate that, for these cases, the streams emanating from within the hole must be very fast, greater than 1000 km s-1, or very wide, greater than 60-degrees, at the inner boundary of 18 solar radii in our simulation. RP SMITH, Z (reprint author), NOAA,SPACE ENVIRONM LAB,RESE3,325 BROADWAY,BOULDER,CO 80303, USA. RI xue, yansheng/A-9712-2012 NR 31 TC 14 Z9 14 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD FEB PY 1991 VL 131 IS 2 BP 363 EP 383 DI 10.1007/BF00151644 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA EX927 UT WOS:A1991EX92700011 ER PT J AU STEIN, SE BROWN, RL AF STEIN, SE BROWN, RL TI PREDICTION OF CARBON HYDROGEN-BOND DISSOCIATION-ENERGIES FOR POLYCYCLIC AROMATIC-HYDROCARBONS OF ARBITRARY SIZE SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID STABILIZED RADICALS; SYSTEMS AB A method has been developed for estimating C-H bond dissociation energies at the edges of polycyclic aromatic hydrocarbons of arbitrary size. A series of reference molecules having well-established bond dissociation enthalpies are used to represent several types of dissociations. For each type, Huckel molecular orbital theory is used to calculate the pi-electron energy difference between reactant and product. This difference is then used to calculate relative bond dissociation enthalpies. Predictions are also made of C-H bond dissociation enthalpies at the perimeters of infinite graphite layers having several different edge structures. Energies depend principally on chemical structures near the bond of interest and little on overall molecular size. Along with available ionization energies, these results results also allow estimation of proton affinities at the edges of a layer of graphite. These proton affinities depend on both the chemical structures at the site of protonation and the overall molecular size. RP STEIN, SE (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899, USA. NR 31 TC 83 Z9 83 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 30 PY 1991 VL 113 IS 3 BP 787 EP 793 DI 10.1021/ja00003a009 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA EW178 UT WOS:A1991EW17800009 ER PT J AU MEOTNER, M SMITH, SC AF MEOTNER, M SMITH, SC TI ENTROPY BARRIERS TO PROTON-TRANSFER SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ION MOLECULE REACTIONS; VARIATIONAL TRANSITION-STATES; GAS-PHASE BASICITIES; ELECTRON CORRELATION; BOTTLENECKS; DEPENDENCE; AMINES AB Proton transfer between sterically hindered pyridines and amines proceeds through locked-rotor, low-entropy intermediates. The reactions exhibit slow kinetics (efficiencies of 0.1-0.0001) and large negative temperature coefficients (up to k = CT8.7). The rates become slower and the temperature dependencies steeper with increasing steric hindrance. The observations are reproduced by a multiple complex-switching RRKM model that allows several alternative complexes to be rate controlling: a series of loose complexes, a locked-rotor tight complex that occurs before the formation of a hydrogen-bonded complex, and a complex located at the central barrier. The rate-limiting transition state shifts from the loose to the tight and central-barrier complexes with increasing temperature. The model suggests that at elevated temperatures, above 1000 K, ion-molecule reactions will become slow even for unhindered, small reactants. Ion kinetics may then become similar to neutral radical kinetics. C1 UNIV CANTERBURY,DEPT CHEM,CHRISTCHURCH 1,NEW ZEALAND. RP MEOTNER, M (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899, USA. RI Smith, Sean/H-5003-2015 OI Smith, Sean/0000-0002-5679-8205 NR 28 TC 64 Z9 64 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 30 PY 1991 VL 113 IS 3 BP 862 EP 869 DI 10.1021/ja00003a020 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA EW178 UT WOS:A1991EW17800020 ER PT J AU CROSS, RW GOLDFARB, RB AF CROSS, RW GOLDFARB, RB TI ENHANCED FLUX CREEP IN NB-TI SUPERCONDUCTORS AFTER AN INCREASE IN TEMPERATURE SO APPLIED PHYSICS LETTERS LA English DT Article ID MAGNETS; FIELDS AB The magnetic fields of Superconducting Super Collider (SSC) dipole magnets change with time when the magnets are operated at constant current. The decay of the field is thought to be a consequence of flux creep in the Nb-Ti filaments in the superconducting cables. However, measured magnetic relaxation of small samples of SSC cable as a function of time is unlike the large decays that are observed in the fields of the actual magnets. We have made relaxation measurements on sample SSC conductors at 3.5 and 4.0 K after field cycling. The decay at both temperatures was 2.8% in 50 min. However, the relaxation measured after a temperature increase from 3.5 to 4.0 K was 4.8% to 50 min. A likely reason for the greater magnetization decay is that, after an increase in temperature, the Nb-Ti is in a supercritical state, with shielding currents flowing at a density greater than the new critical current density. This causes enhanced flux creep. We suggest that a small temperature rise during the operation of SSC magnets may contribute to the unexpectedly large magnetic field decay. RP CROSS, RW (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. RI Goldfarb, Ronald/A-5493-2011 OI Goldfarb, Ronald/0000-0002-1942-7974 NR 11 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 28 PY 1991 VL 58 IS 4 BP 415 EP 416 DI 10.1063/1.104651 PG 2 WC Physics, Applied SC Physics GA EV460 UT WOS:A1991EV46000033 ER PT J AU WALSH, T MORELAND, J ONO, RH KALKUR, TS AF WALSH, T MORELAND, J ONO, RH KALKUR, TS TI TUNNELING MEASUREMENTS OF THE ZERO-BIAS CONDUCTANCE PEAK AND THE BI-SR-CA-CU-O THIN-FILM ENERGY-GAP SO PHYSICAL REVIEW LETTERS LA English DT Article ID JUNCTIONS; BI2SR2CACU2OX; SURFACES AB We have examined the zero-bias conductance peak that is often found in high-temperature-superconductor tunnel-junction spectra. We have also measured the Bi-Sr-Ca-Cu-O thin-film energy gap. The zero-bias conductance peak can be explained in terms of quasiparticle tunneling, phase diffusion, and a supercurrent. The implications of this model are discussed. C1 UNIV COLORADO,COLORADO SPRINGS,CO 80933. RP WALSH, T (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 22 TC 43 Z9 43 U1 1 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 JAN 28 PY 1991 VL 66 IS 4 BP 516 EP 519 DI 10.1103/PhysRevLett.66.516 PG 4 WC Physics, Multidisciplinary SC Physics GA EU786 UT WOS:A1991EU78600031 ER PT J AU NAHOR, GS HAPIOT, P NETA, P HARRIMAN, A AF NAHOR, GS HAPIOT, P NETA, P HARRIMAN, A TI CHANGES IN THE REDOX STATE OF IRIDIUM OXIDE CLUSTERS AND THEIR RELATION TO CATALYTIC WATER OXIDATION - RADIOLYTIC AND ELECTROCHEMICAL STUDIES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID OXYGEN EVOLUTION; AQUA IONS; FILMS; CELL AB Radiolytically prepared iridium oxide (IrO(x).nH2O) clusters have been shown to catalyze the photochemical oxidation of water. These catalysts have been oxidized by radiolytic or electrochemical methods and the changes in their optical absorptions and redox states have been studied. The clusters contain four or five Ir atoms in a mixture of Ir(III) and Ir(IV) states, formally described as Ir3.2+. Time-resolved pulse-radiolytic studies revealed three processes in the subsecond time scale. The first step produces a short-lived intermediate (lambda-max approximately 360 nm), possibly an OH adduct, that is transformed to more stable oxidized species (lambda-max 340 and 580 nm). In the third step, there is a rise in the 580-nm absorption. The same species were observed in gamma-radiolysis and in spectroelectemical experiments. Cyclic voltammetric and coulometric measurements suggest that the initial IrO(x) cluster is oxidized in two stages, from Ir3.2+ to Ir3.8+ and then to Ir4+. Further oxidation of the cluster leads to oxidation of water to O2. The Ir4+ clusters decay within hours or days to regenerate IrO(x) clusters of lower oxidation state by secondary water oxidation. The kinetics of all the above processes are pH dependent and involve acid-base equilibria in the various oxidation states. C1 NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. UNIV TEXAS,CTR FAST KINET RES,AUSTIN,TX 78712. NR 27 TC 41 Z9 41 U1 2 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JAN 24 PY 1991 VL 95 IS 2 BP 616 EP 621 DI 10.1021/j100155a024 PG 6 WC Chemistry, Physical SC Chemistry GA EU486 UT WOS:A1991EU48600024 ER PT J AU JOVANOVIC, SV STEENKEN, S SIMIC, MG AF JOVANOVIC, SV STEENKEN, S SIMIC, MG TI KINETICS AND ENERGETICS OF ONE-ELECTRON-TRANSFER REACTIONS INVOLVING TRYPTOPHAN NEUTRAL AND CATION RADICALS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PULSE-RADIOLYSIS; REDOX POTENTIALS; TYROSINE DERIVATIVES; CHARGE-TRANSFER; MECHANISM; PROTEINS; ANIONS; PHENOL AB Reversible one-electron-transfer reactions involving the tryptophan cation and neutral radicals were investigated byh pulse radiolysis. The one-electron-reduction potential fo the neutral tryptophan radical at pH 7 was determined to be E7 = 1.01 +/- 0.03 V by using the bis(1,4,7-triazacyclononane)nickeld (III/II) redox couple with E = 0.95 V as a standard. The value obtained with promethazine (E = 0.98 V) as a standard at pH 6 was E6 = 1.11 V. From these measurements, a mean value E7 = 1.03 V results, in agreement with some earlier determinations (1.05 and 1.08 V) obtained in experiments with inorganic redox standards. The kietics and energetics of the reactions of the tryptophan neutral and cation radicals with selected electron donors were also investigated. The reactivity of the typtophan radical cation was found to be 1-2 orders of magnitude higher than that of the neutral radical. The lower reactivity of the neutral tryptophan radical is explained by the entropy loss due to protonation of the tryptophan anion, resulting from the changes in the solvation shell. C1 NATL INST STAND & TECHNOL,CTR RADIAT RES,GAITHERSBURG,MD 20899. MAX PLANCK INST STRAHLENCHEM,W-4330 MULHEIM,GERMANY. RP JOVANOVIC, SV (reprint author), BORIS KIDRIC INST NUCL SCI,LAB 030,POB 522,YU-11001 BELGRADE,YUGOSLAVIA. NR 25 TC 60 Z9 60 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JAN 24 PY 1991 VL 95 IS 2 BP 684 EP 687 DI 10.1021/j100155a035 PG 4 WC Chemistry, Physical SC Chemistry GA EU486 UT WOS:A1991EU48600035 ER PT J AU HARVEY, AH SENGERS, JMHL TANGER, JC AF HARVEY, AH SENGERS, JMHL TANGER, JC TI UNIFIED DESCRIPTION OF INFINITE-DILUTION THERMODYNAMIC PROPERTIES FOR AQUEOUS SOLUTES SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PARTIAL MOLAR VOLUMES; HEAT-CAPACITIES; CRITICAL-POINT; ARGON; ETHYLENE; MIXTURES; 600-K; XENON; GASES; WATER AB A linear expression, asymptotically correct near a solvent's critical point, is derived relating Henry's constant of a solute to the density of the pure solvent. Since the expression is general (i.e. not restricted to the solvent's saturation curve), it may be differentiated to yield other infinite-dilution thermodynamic properties such as partial molar volumes. This enables these properties for a solute to be predicted from a single fit of the Henry's constant expression to solubility data. Such predictions are compared with published measurements of apparent molar volumes and apparent molar heat capacities for aqueous argon, xenon, and ethylene. The volumes are predicted well over a wide range of conditions including the region near water's critical point, where large effects are observed. Agreement with heat capacity data is only qualitative; we show that this may be in part a consequence of a higher order term in the asymptotic expression that becomes important after two differentiations. The divergent behavior of the infinite-dilution properties near the critical point is determined by divergences in pure-solvent properties; the only solute dependence is in the amplitude of the divergence, which is proportional to the slope of the Henry's constant expression. While the experimental Henry's constant data yield a very large linear region, it now appears that the slope in this region is not the true asymptotic slope. Nevertheless, it appears that predictions of infinite-dilution thermodynamic properties based on Henry's constants are adequate over a wide range of conditions. C1 NATL INST STAND & TECHNOL,DIV CHEM THERMODYNAM,GAITHERSBURG,MD 20899. RP HARVEY, AH (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 31 TC 58 Z9 58 U1 2 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JAN 24 PY 1991 VL 95 IS 2 BP 932 EP 937 DI 10.1021/j100155a079 PG 6 WC Chemistry, Physical SC Chemistry GA EU486 UT WOS:A1991EU48600079 ER PT J AU NYDEN, MR NOID, DW AF NYDEN, MR NOID, DW TI MOLECULAR-DYNAMICS OF INITIAL EVENTS IN THE THERMAL-DEGRADATION OF POLYMERS SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID COMPUTER-SIMULATION AB Computer simulations, based on molecular dynamics, were used to investigate the kinetic stability of model polymers as a function of temperature, secondary structure, and molecular weight. The rate constants for random scission of the carbon-carbon bonds were obtained from simulations starting from both planar zigzag and coiled conformations. The coiled polymers were found to be more stable than planar zigzag polymers with the same primary structure. The computer-generated rates correlated reasonably well with the functional predictions of the Rice, Ramsperger, and Kassel theory of unimolecular reactivity; however, deviations were observed for some of the short-chained polymers. Computer movies revealed pronounced coiling in the vicinity of dissociating bonds. This behavior was examined in light of proposed mechanisms for intramolecular hydrogen transfer. C1 OAK RIDGE NATL LAB,DIV CHEM,OAK RIDGE,TN 37831. RP NYDEN, MR (reprint author), NATL INST STAND & TECHNOL,CTR FIRE RES,GAITHERSBURG,MD 20899, USA. NR 18 TC 23 Z9 25 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JAN 24 PY 1991 VL 95 IS 2 BP 940 EP 945 DI 10.1021/j100155a081 PG 6 WC Chemistry, Physical SC Chemistry GA EU486 UT WOS:A1991EU48600081 ER PT J AU DESROSIERS, MF COURSEY, BM AVILA, MJ PARKS, NJ AF DESROSIERS, MF COURSEY, BM AVILA, MJ PARKS, NJ TI RADIATION-DOSES SO NATURE LA English DT Letter C1 UNIV CALIF DAVIS,ENERGY RELATED HLTH RES LAB,DAVIS,CA 95616. RP DESROSIERS, MF (reprint author), NATL INST STAND & TECHNOL,CTR RADIAT RES,GAITHERSBURG,MD 20899, USA. NR 4 TC 11 Z9 12 U1 0 U2 1 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD JAN 24 PY 1991 VL 349 IS 6307 BP 287 EP 288 DI 10.1038/349287b0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA EU501 UT WOS:A1991EU50100032 PM 1846228 ER PT J AU HE, MJ LIU, YM YI, F MING, J HAN, CC AF HE, MJ LIU, YM YI, F MING, J HAN, CC TI SPINODAL DECOMPOSITION IN A HYDROGEN-BONDED POLYMER BLEND SO MACROMOLECULES LA English DT Article ID ANGLE NEUTRON-SCATTERING; POLYVINYL METHYL-ETHER); PHASE-BEHAVIOR; POLY(2,6-DIMETHYL-1,4-PHENYLENE OXIDE); SEMIDILUTE SOLUTION; BINARY-MIXTURES; POLYSTYRENE; MISCIBILITY; THERMODYNAMICS; SHEAR AB The spinodal decomposition of a hydrogen-bonded binary blend, which consists of a polystyrene with 1.5 mol % of p-(1,1,1,3,3,3-hexafluoro-2-hydroxyisopropyl)-a-methylstyrene comonomer and a poly(butyl methacrylate), has been studied. This system has a LCST with a very asymmetrical phase diagram. Also the critical point does not coincide with the temperature minimum of either the spinodal or the cloud-point curve. The kinetics follows the Cahn-Hilliard-Cook model for early spinodal decomposition and a self-similar mechanism for late-stage coarsening for most cases. For shallow quench cases and for close to glass transition temperature cases, double peaks have been observed during spinodal decomposition, which suggests that a second or an alternative relaxation mechanism may be dominating the coarsening process. A special procedure has been developed to measure the cloud point for this system, which should be applicable to any polymer blend system that has a cloud temperature close to the glass transition temperature. C1 NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. E CHINA UNIV CHEM TECHNOL,DEPT POLYMER SCI & ENGN,SHANGHAI 200237,PEOPLES R CHINA. FUDAN UNIV,INST MAT SCI,SHANGHAI 200433,PEOPLES R CHINA. NR 44 TC 42 Z9 44 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JAN 21 PY 1991 VL 24 IS 2 BP 464 EP 473 DI 10.1021/ma00002a020 PG 10 WC Polymer Science SC Polymer Science GA EU814 UT WOS:A1991EU81400020 ER PT J AU FISCHBACH, E GREENE, GL HUGHES, RJ AF FISCHBACH, E GREENE, GL HUGHES, RJ TI NEW TEST OF QUANTUM-MECHANICS - IS PLANCK CONSTANT UNIQUE SO PHYSICAL REVIEW LETTERS LA English DT Article ID FINE-STRUCTURE CONSTANT; NEUTRON AB We discuss the possibility that different realms of physics are described by distinct quantization constants. From the consistency of existing data, we infer limits on the differences between hypothetically distinct quantization constants for different elementary particles. Since the existence of multiple Planck constants implies violations of space-time symmetries, these limits may be viewed as precise tests of fundamental conservation laws, including the conservation of linear momentum and energy. C1 NATL INST STANDARDS & TECHNOL,GAITHERSBURG,MD 20899. UNIV CALIF LOS ALAMOS SCI LAB,DIV PHYS,LOS ALAMOS,NM 87545. RP FISCHBACH, E (reprint author), PURDUE UNIV,DEPT PHYS,W LAFAYETTE,IN 47907, USA. NR 17 TC 9 Z9 9 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 JAN 21 PY 1991 VL 66 IS 3 BP 256 EP 259 DI 10.1103/PhysRevLett.66.256 PG 4 WC Physics, Multidisciplinary SC Physics GA ET680 UT WOS:A1991ET68000003 ER PT J AU CIOFFI, DF SHULL, JM AF CIOFFI, DF SHULL, JM TI SIMULATIONS OF THE SUPERNOVA-DOMINATED INTERSTELLAR-MEDIUM IN DISK GALAXIES SO ASTROPHYSICAL JOURNAL LA English DT Article DE GALAXIES, INTERSTELLAR MATTER; NEBULAE, SUPERNOVA REMNANTS ID LARGE MAGELLANIC CLOUD; ADIABATIC BLAST WAVES; INTER-STELLAR MEDIUM; H-I HALO; NOVA REMNANTS; MOLECULAR CLOUDS; STAR FORMATION; SPHERICAL CLOUDS; GASEOUS HALO; CORONAL GAS AB preventing the establishment of long-lived "tunnel" networks of hot rarefied gas. remnants (SNRs). We have developed a computer stimulation that uses standard SNR evolutionary solutions to redistribute mass and energy throughout a rectangular, three-level grid. This model includes bremsstrahlung or metal cooling, creation and evaporation of clouds, mass injection to and return from a galactic halo, multiple correlated SNRs, and internally determined SNR lifetimes; we neglected magnetic fields and cooling by dust. We have confirmed the suspicion that spatial correlation of supernova sites can increase the global evolution rate of the metal-cooled ISM. Porosity theory is unable to predict the topology of the interstellar medium because it does not account for mass transport, averaging 0.007 M. pc-2 Myr-1 and 2 M. pc-2 into the halo. In "primeval" (zero metal abundance) galaxies, the enhanced mass transport by bremsstrahlung-cooled remnants continually agitates the ISM, preventing the establishment of long-lived "tunnel" networks of hot rarefied gas. One cannot use the simple SNR number-radius relation to infer evolutionary histories, because of its implicit assumptions of a homogeneous mass density and constant SNR lifetimes; a simple N(R) histogram conveys more information. If SNR shells are the main source of cold clouds in present-day galaxies, the initial size of the clouds can determine the global structure of the ISM. With small clouds (<< 1 pc) that are easily evaporated, less than 25% of interstellar material will be "locked up" in atomic hydrogen, leaving most of the material in a warm or hot phase at high pressure. If the created clouds are of the more usually assumed size (approximately 1 pc), about 70% of the disk mass will remain in cold, cloudy state, and the pressure assumes more conventional interstellar values. C1 NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO. CTR ASTROPHYS & SPACE ASTRON,BOULDER,CO. NR 113 TC 30 Z9 30 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 20 PY 1991 VL 367 IS 1 BP 96 EP 114 DI 10.1086/169606 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ER078 UT WOS:A1991ER07800010 ER PT J AU WILLIAMS, EJ FEHSENFELD, FC AF WILLIAMS, EJ FEHSENFELD, FC TI MEASUREMENT OF SOIL-NITROGEN OXIDE EMISSIONS AT 3 NORTH-AMERICAN ECOSYSTEMS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NITRIC-OXIDE; FIELD-MEASUREMENTS; UNITED-STATES; FOREST; NO; GRASSLAND; FLUXES AB Results from measurements of emission of nitrogen oxides from soils at three North American ecosystems are presented. These measurements were conducted during the summer and fall of 1988 at (1) a grassland site near Nunn, Colorado, (2) a coastal marine environment at North Inlet, South Carolina and (3) a deciduous forest near Oak Ridge, Tennessee. Emission of NO was highest from the grassland soil (mean: 10.0 ng N m-2s-1), intermediate at the forest area (mean: 0.28 ng N m-2s-1) and lowest at the coastal site (mean: 0.034 ng N m-2s-1). A comparison of the results from the present study with previous measurements indicates that NO(x) (NO + NO2) emission from grasslands and temperate forests are similar within each ecosystem independent of location. This suggests that simple approaches may be used to estimate soil emissions over wide areas. C1 UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP WILLIAMS, EJ (reprint author), NOAA, ERL, AERON LAB, R-E-AL7, 325 S BROADWAY, BOULDER, CO 80303 USA. RI Williams, Eric/F-1184-2010; Fehsenfeld, Frederick/I-4876-2013 NR 31 TC 96 Z9 98 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD JAN 20 PY 1991 VL 96 IS D1 BP 1033 EP 1042 DI 10.1029/90JD01903 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA EV403 UT WOS:A1991EV40300011 ER PT J AU KINSEL, GR MOWRY, CD MCKEOWN, PJ JOHNSTON, MV AF KINSEL, GR MOWRY, CD MCKEOWN, PJ JOHNSTON, MV TI RESOLUTION ENHANCEMENT IN LINEAR TIME-OF-FLIGHT MASS-SPECTROMETRY BY POST-SOURCE PULSE FOCUSING SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article AB Resolution enhancement in linear time-of-flight mass spectrometry is demonstrated for a new technique, post-source pulse focusing. The relatively simple procedure followed to perform pulse focusing is described including a discussion of the need to choose proper experimental conditions. A resolving power of ca. 1500 for m/z 228 is demonstrated. Finally, equations are presented which allow the electric field conditions necessary for optimum pulse focusing to be estimated for instruments with a wide range of instrumental configurations. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NR 6 TC 17 Z9 17 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1176 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. Ion Process. PD JAN 15 PY 1991 VL 104 IS 1 BP 35 EP 44 DI 10.1016/0168-1176(91)85003-5 PG 10 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA EW210 UT WOS:A1991EW21000003 ER PT J AU FRENCH, VA POWELL, RC BLACKBURN, DH CRANMER, DC AF FRENCH, VA POWELL, RC BLACKBURN, DH CRANMER, DC TI REFRACTIVE-INDEX GRATINGS IN RARE-EARTH-DOPED ALKALINE-EARTH GLASSES SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LASER-INDUCED GRATINGS AB Four-wave-mixing techniques were used to produce permanent laser-induced refractive index gratings in Eu3+ -doped silicate glasses. These gratings are associated with a thermally induced change in the local glass structure at the site of the Eu3+ ions, leading to a double-minimum potential well for the electronic energy levels of the Eu3+ ions. The effects on the characteristics of the permanent laser-induced gratings produced by changing the divalent modifier ions of the glass host are reported and a theoretical model is presented to explain the physical origin of the change in the refractive index of the material. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20894. RP FRENCH, VA (reprint author), OKLAHOMA STATE UNIV,CTR LASER RES,STILLWATER,OK 74078, USA. NR 11 TC 20 Z9 20 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 1991 VL 69 IS 2 BP 913 EP 917 DI 10.1063/1.347333 PG 5 WC Physics, Applied SC Physics GA EU225 UT WOS:A1991EU22500060 ER PT J AU ROY, P BARTLETT, RJ TRELA, WJ FERRETT, TA PARR, AC SOUTHWORTH, SH HARDIS, JE SCHMIDT, V DEHMER, JL AF ROY, P BARTLETT, RJ TRELA, WJ FERRETT, TA PARR, AC SOUTHWORTH, SH HARDIS, JE SCHMIDT, V DEHMER, JL TI VIBRONIC COUPLING AND OTHER MANY-BODY EFFECTS IN THE 4-SIGMA-G(-1) PHOTOIONIZATION CHANNEL OF CO2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PHOTOELECTRON ANGULAR-DISTRIBUTIONS; IONIZATION CROSS-SECTIONS; SHAPE-RESONANCE; HIGH-RESOLUTION; PHOTO-IONIZATION; SYNCHROTRON RADIATION; CARBON-DIOXIDE; ASYMMETRY PARAMETERS; SPECTROMETER SYSTEM; BRANCHING RATIOS AB Vibrational branching ratios and photoelectron angular distributions were measured for 4-sigma-g-1 photoionization of CO2 in the energy range 20-28 eV. Of particular interest are three vibrational components of the resulting CO2+ C approximately 2-SIGMA-g+ state-the allowed (000) and (100) bands and the forbidden (101) band. The wavelength dependence of the beta parameter for the forbidden band deviated significantly from that of the two allowed bands, showing instead a strong resemblance to that of the B approxiately 2-SIGMA-u+ state. This behaviour suggests that vibronic coupling to the B approximately 2-SIGMA-u+ state the responsible for the appearance of the (101) band in the C approximately 2-SIGMA-g+ state photoelectron spectrum. We also observe evidence for other many-body effects-shape-resonance-induced continuum-continuum coupling and doubly excited autoionizing resonances-in the present data. C1 UNIV CALIF LOS ALAMOS SCI LAB,LOS ALAMOS,NM 87545. NIST,DIV RADIOMETR,GAITHERSBURG,MD 20899. NIST,DIV RADIAT PHYS,GAITHERSBURG,MD 20899. UNIV FREIBURG,FAK PHYS,W-7800 FREIBURG,GERMANY. ARGONNE NATL LAB,ARGONNE,IL 60439. NR 63 TC 20 Z9 20 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 1991 VL 94 IS 2 BP 949 EP 956 DI 10.1063/1.459985 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA EU592 UT WOS:A1991EU59200014 ER PT J AU MCPHADEN, MJ HANSEN, DV RICHARDSON, PL AF MCPHADEN, MJ HANSEN, DV RICHARDSON, PL TI A COMPARISON OF SHIP DRIFT, DRIFTING BUOY, AND CURRENT-METER MOORING VELOCITIES IN THE PACIFIC SOUTH EQUATORIAL CURRENT SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID EL-NINO; ATLANTIC; VARIABILITY AB In this note we compare mean seasonal cycles of zonal and meridional velocity in the Pacific South Equatorial Current based on current meter mooring data, drifting buoy data, and ship drift data. Monthly averages of ship drift and drifting buoy data were computed over 2-degrees latitude by 10-degrees longitude rectangles centered at the positions of multiyear current meter moorings near 0-degrees, 110-degrees-W, and 0-degrees, 140-degrees-W. All three representations of the flow field show the basic character of the annual mean and its variations, provided that the sampling characteristics associated with each measurement technique are taken into account. In particular we find that more than 15 days of drifter data (regardless of year) are required on a 2-degrees latitude by 10-degrees longitude basis to produce monthly mean estimates that agree with moored estimates to within about 5-10 cm s-1 rms. We also infer that windage affects climatological monthly mean ship drift velocities, although uncertainties in the data limit a precise determination of the windage magnitude. An upper bound appears to be about 3% of the surface wind speed, though the actual effect of windage may be considerably smaller. C1 NOAA,ATLANTIC OCEANOG & METEOROL LAB,MIAMI,FL 33149. WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. RP MCPHADEN, MJ (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI McPhaden, Michael/D-9799-2016 NR 16 TC 12 Z9 12 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JAN 15 PY 1991 VL 96 IS C1 BP 775 EP 781 DI 10.1029/90JC02136 PG 7 WC Oceanography SC Oceanography GA FD792 UT WOS:A1991FD79200004 ER PT J AU LAVELLE, JW CUDABACK, CN PAULSON, AJ MURRAY, JW AF LAVELLE, JW CUDABACK, CN PAULSON, AJ MURRAY, JW TI A RATE FOR THE SCAVENGING OF FINE PARTICLES BY MACROAGGREGATES IN A DEEP ESTUARY SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID MARINE SNOW; VERTICAL FLUX; OCEAN; TRANSPORT; THORIUM; DYNAMICS; FJORD; WATER; SEA AB Th-234 activity profiles in Puget Sound have been studied using a model that incorporates reversible exchanges between dissolved, fine particulate, and macroaggregate Th reservoirs. Macroaggregate settling is made responsible for the downward flux of Th and the vertical gradients of activity in measured profiles. Least squares fits of model to data yield rates/time scales for the exchange processes involved. Fine-particle scavenging by macroaggregates is found to occur with a time scale of 4-6 days over a large range of macroaggregate settling speeds, w(s). Macroaggregate-disaggregation time scales are 1-4 days when w(s) is 100 m/d. Rates of sorption and remobilization characterizing the exchange between dissolved and fine-particulate forms of the isotope cannot be individually identified from these data, but acceptable model values include those measured in the laboratory. Rates of sorption that depend on particulate concentrations which increase to the seafloor result in profiles of dissolved Th having above-bottom maxima. Based on inferred exchange rates, the residence time for fine particles introduced at the surface of this deep (approximately 200 m) estuary is estimated to be 11-16 days when w(s) = 100 m/d. C1 UNIV WASHINGTON,SCH OCEANOG,SEATTLE,WA 98195. RP LAVELLE, JW (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. OI Murray, James/0000-0002-8577-7964 NR 30 TC 7 Z9 8 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JAN 15 PY 1991 VL 96 IS C1 BP 783 EP 790 DI 10.1029/90JC02197 PG 8 WC Oceanography SC Oceanography GA FD792 UT WOS:A1991FD79200005 ER PT J AU WILLIS, PT HALLETT, J AF WILLIS, PT HALLETT, J TI MICROPHYSICAL MEASUREMENTS FROM AN AIRCRAFT ASCENDING WITH A GROWING ISOLATED MARITIME CUMULUS TOWER SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID ICE NUCLEATION; CONDENSATION; COALESCENCE; CLOUDS AB The development of precipitation in the top of an isolated maritime cumulus tower is traced by four rapid penetrations with an instrumented aircraft between 400 and 1000 m below the visible top of the growing tower. The hydrometeor distribution evolves from the first appearance of a few large supercooled drops [0.45 l-1, D > 0.5 mm] to well developed precipitation (largely ice) in 500 s. This development results from accretion and coalescence growth in the cloud top volume, not from advection by the updraft of large drops from below. Large supercooled drops precede the appearance of ice at -9-degrees-C near the cloud top. The cloud- and precipitation-water budgets are computed and compared with observed values, which indicate that, once precipitation is well developed, the convective tower cannot maintain itself as a steady state entity. The budget computations demonstrate a sensitvity of cloud evolution to the ice particle density. C1 UNIV NEVADA,DESERT RES INST,RENO,NV 89557. RP WILLIS, PT (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,DIV HURRICANE RES,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. RI Willis, Paul/I-7034-2013 OI Willis, Paul/0000-0003-4506-9813 NR 25 TC 14 Z9 14 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD JAN 15 PY 1991 VL 48 IS 2 BP 283 EP 300 DI 10.1175/1520-0469(1991)048<0283:MMFAAA>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA EZ849 UT WOS:A1991EZ84900004 ER PT J AU DATLA, RU ROBERTS, JR BHATIA, AK AF DATLA, RU ROBERTS, JR BHATIA, AK TI RELATIVE POPULATIONS OF EXCITED-LEVELS WITHIN THE GROUND CONFIGURATION OF SI-LIKE CU, ZN, GE, AND SE IONS SO PHYSICAL REVIEW A LA English DT Note ID EXCITATION; XVII; LINES; NI AB Populations of 3p2 1D2, 3P1, 3P2 levels in Si-like Cu, Zn, Ge, and Se ions have been deduced from the measurements of absolute intensities of magnetic dipole transitions within the 3s(2)3p2 ground configuration. Observations have been made in the Texas Experimental Tokamak (TEXT). The measured population ratios are compared with theoretical calculations based on the distorted-wave approximation for the electron collisions and a semiclassical approximation for the proton collisions. The observed deviation from the statistical distribution for the excited-level populations within the ground configuration along the silicon isoelectronic sequence is in agreement with theoretical prediction. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP DATLA, RU (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JAN 15 PY 1991 VL 43 IS 2 BP 1110 EP 1113 DI 10.1103/PhysRevA.43.1110 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA EU856 UT WOS:A1991EU85600054 ER PT J AU WADA, N KAMITAKAHARA, WA AF WADA, N KAMITAKAHARA, WA TI INELASTIC NEUTRON-SCATTERING AND RAMAN-SCATTERING STUDIES OF MUSCOVITE AND VERMICULITE LAYERED SILICATES SO PHYSICAL REVIEW B LA English DT Article ID INTERCALATION COMPOUNDS; RIGIDITY; SOLIDS; WATER AB Investigations on the lattice dynamics of muscovite and vermiculite have been carried out by inelastic neutron scattering and Raman scattering. In the neutron measurements, dispersion curves for the out-of-plane and in-plane LA and TA phonons were fully obtained for muscovite, while more limited data were obtained for Mg vermiculite. Sound velocities were estimated from the slopes of the dispersion curves. Raman-scattering experiments revealed an interlayer shearing mode in Na and Sr vermiculites in the O-water-layer hydration state. The intercalated water molecules in Na and Sr vermiculites exhibited a broad Raman feature (OH stretching vibrations) at 3450 cm-1 with a full width at half maximum of approximately 300 cm-1. In addition, relatively sharp Raman peaks from the inner-layer hydroxyls in the host octahedral layers were found at approximately 3700 cm-1. These peaks were sensitive to the hydration state or charge in the intercalated layer. C1 IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. UNIV MARYLAND,COLLEGE PK,MD 20742. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP WADA, N (reprint author), COLORADO STATE UNIV,DEPT PHYS,FT COLLINS,CO 80523, USA. NR 17 TC 34 Z9 34 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1991 VL 43 IS 3 BP 2391 EP 2397 DI 10.1103/PhysRevB.43.2391 PG 7 WC Physics, Condensed Matter SC Physics GA EV605 UT WOS:A1991EV60500062 ER PT J AU WOICIK, JC BOULDIN, CE BELL, MI CROSS, JO TWEET, DJ SWANSON, BD ZHANG, TM SORENSEN, LB KING, CA HOYT, JL PIANETTA, P GIBBONS, JF AF WOICIK, JC BOULDIN, CE BELL, MI CROSS, JO TWEET, DJ SWANSON, BD ZHANG, TM SORENSEN, LB KING, CA HOYT, JL PIANETTA, P GIBBONS, JF TI CONSERVATION OF BOND LENGTHS IN STRAINED GE-SI LAYERS SO PHYSICAL REVIEW B LA English DT Note ID HETEROJUNCTION BIPOLAR-TRANSISTORS; ABSORPTION FINE-STRUCTURE; ALLOYS AB The combined techniques of x-ray-absorption fine structure and x-ray diffraction have been used to study the strain and bond distortions in epitaxial Ge-Si on Si(001). In a 31% Ge, 340-angstrom pseudomorphic Ge-Si film, the Ge-Ge and Ge-Si first-neighbor bond lengths have been found to be 2.44 +/- 0.02 and 2.38 +/0 0.02 angstrom, respectively. The lattice parameter perpendicular to the Ge-Si/Si(001) interface has been found to be alpha-perpendicular-to = 5.552 +/- 0.002 angstrom, in agreement with the predictions of macroscopic elastic theory. These results show that the bond-length strain in the epitaxial layer appears in the second and higher coordination shells, rather than in the nearest-neighbor bond lengths, which remain the same as in unstrained Ge-Si. A microscopic model is presented that accounts for these findings. C1 UNIV WASHINGTON,DEPT PHYS FM-15,SEATTLE,WA 98195. STANFORD UNIV,STANFORD ELECTR LABS,STANFORD,CA 94305. RP WOICIK, JC (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 13 TC 67 Z9 67 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1991 VL 43 IS 3 BP 2419 EP 2422 DI 10.1103/PhysRevB.43.2419 PG 4 WC Physics, Condensed Matter SC Physics GA EV605 UT WOS:A1991EV60500069 ER PT J AU WAHLIN, EK THOMPSON, JS DUNN, GH PHANEUF, RA GREGORY, DC SMITH, ACH AF WAHLIN, EK THOMPSON, JS DUNN, GH PHANEUF, RA GREGORY, DC SMITH, ACH TI ELECTRON-IMPACT EXCITATION OF SI3+(3S-]3P) USING A MERGED-BEAM ELECTRON-ENERGY-LOSS TECHNIQUE SO PHYSICAL REVIEW LETTERS LA English DT Article ID CROSS-SECTIONS; IONS AB For the first time, absolute cross sections for electron-impact excitation of a multiply charged ion have been measured using an electron-energy-loss technique. Cross sections for e + Si3+ (3s 2S1/2) --> e + Si3+ (3p 2P1/2, 3/2) - 8.88 eV have been measured with an accuracy of +/- 20% (at 90%-confidence level) over a narrow energy range (+/- 0.6 eV) about the threshold energy with an energy resolution of 0.2 eV. Results are in good agreement with close-coupling calculations. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV LONDON UNIV COLL,LONDON WC1E 6BT,ENGLAND. RP WAHLIN, EK (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. OI Thompson, Jeffrey/0000-0001-9699-5767 NR 15 TC 46 Z9 46 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 JAN 14 PY 1991 VL 66 IS 2 BP 157 EP 160 DI 10.1103/PhysRevLett.66.157 PG 4 WC Physics, Multidisciplinary SC Physics GA ER720 UT WOS:A1991ER72000009 ER PT J AU OLSSON, M SANDER, LC WISE, SA AF OLSSON, M SANDER, LC WISE, SA TI COMPARISON OF THE LIQUID-CHROMATOGRAPHIC BEHAVIOR OF SELECTED STEROID ISOMERS USING DIFFERENT REVERSED-PHASE MATERIALS AND MOBILE PHASE COMPOSITIONS SO JOURNAL OF CHROMATOGRAPHY LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; CYCLODEXTRIN-BONDED PHASES; COLUMN SELECTIVITY; STATIONARY PHASES; SEPARATION AB The retention behaviour of steroid isomers in reversed-phase liquid chromatography was studied. Selectivity for the isomers changed as a function of both temperature and mobile-phase composition. In addition, the influence of the stationary phase on steroid retention and selectivity was studied for a number of monomeric and polymeric C-18 columns and beta-cyclodextrin columns. The selectivity of a polymeric C-18 phase toward various androstane standards was similar to that for a liquid crystal phase used in supercritical fluid chromatography. C1 NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899. RP OLSSON, M (reprint author), KABI PHARMA RES & DEV,S-11287 STOCKHOLM,SWEDEN. NR 26 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR PD JAN 11 PY 1991 VL 537 IS 1-2 BP 73 EP 83 DI 10.1016/S0021-9673(01)88887-7 PG 11 WC Chemistry, Analytical SC Chemistry GA EW297 UT WOS:A1991EW29700006 ER PT J AU BLACK, MT ZUBER, MT MCADOO, DC AF BLACK, MT ZUBER, MT MCADOO, DC TI COMPARISON OF OBSERVED AND PREDICTED GRAVITY PROFILES OVER APHRODITE TERRA, VENUS SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS LA English DT Article ID GEOID ANOMALIES; HEAT-FLOW; TOPOGRAPHY; MODEL; OCEAN; CONVECTION; BATHYMETRY; TECTONICS; EVOLUTION; FIELD AB We compare observed Pioneer Venus orbiter (PVO) gravity profiles over Aphrodite Terra to profiles predicted from models of thermal isostasy, mantle convection, and Airy compensation. Similar approaches are used in order to investigate how well the models can be distinguished with the PVO data. Topography profiles across Aphrodite are compared to model spreading ridge profiles in order to further assess this model. Airy compensation depths and convection layer thicknesses are greater under eastern Aphrodite than western Aphrodite. Compensation depths in the east are greater than most estimates of lithospheric thickness, suggesting that this part of the ridge is dynamically supported. In parts of western Aphrodite, the spreading ridge model gravity provides a better fit to the data than either Airy compensation or mantle convection. Best-fit spreading rates are between 0.3 and 1.6 cm/yr. Airy compensation and mantle convection cannot be distinguished in most places using only PVO data. C1 NOAA,NATL OCEAN SERV,NATL GEODET SURVEY,CHARTING & GEODET SERV,ROCKVILLE,MD 20852. NASA,GODDARD SPACE FLIGHT CTR,GEODYNAM BRANCH,GREENBELT,MD 20771. RP BLACK, MT (reprint author), UNIV MARYLAND,ASTRON PROGRAM,COLLEGE PK,MD 20742, USA. RI McAdoo, Dave/F-5612-2010 OI McAdoo, Dave/0000-0002-7533-5564 NR 41 TC 11 Z9 12 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-SOLID PD JAN 10 PY 1991 VL 96 IS B1 BP 301 EP 315 DI 10.1029/90JB01853 PG 15 WC Geosciences, Multidisciplinary SC Geology GA ER677 UT WOS:A1991ER67700001 ER PT J AU ZHANG, ZY LIU, RZ HUIE, RE KURYLO, MJ AF ZHANG, ZY LIU, RZ HUIE, RE KURYLO, MJ TI A GAS-PHASE REACTIVITY STUDY OF OH RADICALS WITH 1,1-DICHLOROETHENE AND CIS-1,2-DICHLOROETHENE AND TRANS-1,2-DICHLOROETHENE OVER THE TEMPERATURE-RANGE 240-400-K SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID RATE CONSTANTS; HYDROXYL RADICALS; KINETICS AB Rate constants have been measured for the reactions of hydroxyl radicals with the three dichloroethenes over the temperature range 240-400 K by using the flash photolysis-resonance fluorescence technique. The Arrhenius equations derived from the data obtained predominantly at 35-Torr total pressure (in Ar) are (in units of cm3 molecule-1 s-1) k(trans-1,2-dichloroethene) = (9.37 +/- 1.47) X 10(-13) exp[(283 +/- 85)/T], k(cis-1,2-dichloroethene) = (2.21 +/- 0.34) X 10(-12) exp[(65 +/- 89)/T], and k(1,1-dichloroethene) = (2.30 +/- 0.44) X 10(-12) exp[(472 +/- 105)/T]. There was no apparent effect of pressure on the rate constant for the reaction of OH with trans-1,2-dichloroethene over the range 5-50 Torr (with Ar). C1 NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899. RI Huie, Robert/A-5645-2010; Kurylo, Michael/H-2201-2012 NR 8 TC 24 Z9 24 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD JAN 10 PY 1991 VL 95 IS 1 BP 194 EP 196 DI 10.1021/j100154a039 PG 3 WC Chemistry, Physical SC Chemistry GA ER473 UT WOS:A1991ER47300039 ER PT J AU JINNAI, H HASEGAWA, H HASHIMOTO, T HAN, CC AF JINNAI, H HASEGAWA, H HASHIMOTO, T HAN, CC TI TIME-RESOLVED SMALL-ANGLE NEUTRON-SCATTERING IN INTERMEDIATE-STAGE AND LATE-STAGE SPINODAL DECOMPOSITION OF DPB HPI BLENDS SO MACROMOLECULES LA English DT Article ID BINARY POLYMER MIXTURE; PHASE-SEPARATION; MOLECULAR-WEIGHT; POLYVINYL METHYL-ETHER); LIQUID MIXTURES; POLYSTYRENE; KINETICS; FLUCTUATION; DYNAMICS; BEHAVIOR AB Time-resolved small-angle neutron scattering (SANS) experiments were performed to study the later stage (i.e., the intermediate stage and the late stage) of spinodal decomposition (SD) of a critical mixture of perdeuterated polybutadiene (DPB) and protonated polyisoprene (HPI) with an LCST-type phase diagram and a critical temperature T(c) = 36.1-degrees-C. Time-sliced SANS intensity, S(q,t), is generally composed of the scattering due to growing domains, I(d)(q,t), and that due to the thermally induced local composition fluctuations inside the domain I(T)(q,t) where q and t are the scattering vector and time, respectively. S(q,t) as a function of q shows the "spatial crossover" such that at q much below and above a time-dependent wavenumber, q(s)(t), it depends only on I(d)(q,t) and I(T)(q,t), respectively. The time evolution of the composition difference between the two coexisting domains, DELTA-PHI(t), was determined from I(T)(q,t), which was found to be consistent with the prediction of the scattering theory based upon the random-phase approximation. DELTA-PHI(t) was found to increase with t and reach a constant equilibrium value DELTA-PHI-e at t > t(cr), where t(cr) is the crossover time from the intermediate to the late-stage SD. The crossover wavenumber, q(s)(t), also underwent a characteristic change at t(cr). C1 KYOTO UNIV,DEPT POLYMER CHEM,KYOTO 606,JAPAN. NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. RI Jinnai, Hiroshi/F-8456-2014 NR 36 TC 39 Z9 39 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JAN 7 PY 1991 VL 24 IS 1 BP 282 EP 289 DI 10.1021/ma00001a043 PG 8 WC Polymer Science SC Polymer Science GA ER452 UT WOS:A1991ER45200043 ER PT J AU BASCH, H STEVENS, WJ AF BASCH, H STEVENS, WJ TI THE STRONG HYDROGEN-BOND IN THE FORMIC ACID-FORMATE ANION SYSTEM SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID GAS-PHASE; ABINITIO CALCULATIONS; ION SOLVATION; ENERGIES AB Hydrogen bond energies and geometric structures of several symmetric and asymmetric formic acid-formate anion dimer complexes have been determined. Ab initio gradient optimization at the self-consistent field (SCF) level in a double-zeta + polarization + diffuse Gaussian function basis set was followed by a series of second-order Moller-Plesset (MP2) single-point calculations for the lowest energy structures. The equilibrium asymmetric dimer with the (anti) formic acid-(syn) formate anion conformation has the highest binding energy on both the SCF and MP2 levels at 28.8 and 33.0 kcal/mol, respectively. Experimentally, a gas-phase DELTA-H-degrees D value of 36.8 kcal/mol has been reported for the biformate anion (Meot-Ner, M.; Sieck, L. W. J. Am. Chem. Soc. 1986, 108, 7525). The calculated stability of this anti dimer includes a C-H...O interaction that is estimated to contribute approximately 2.4 (SCF) or approximately 1.8 (MP2) kcal/mol to the dimer binding energy. The corresponding proton-transferred (syn) formic acid-(anti) formate anion complex is calculated less stable by 5.6 (SCF) or 3.7 (MP2) kcal/mol, even though in the isolated monomer syn-formic acid is the lower energy conformer by 5.8 (SCF) or 5.4 (MP2) kcal/mol in the same basis set. The greater stability of the anti dimer can be attributed both to less interfragment exchange repulsion and to more coulomb attraction compared with the syn dimer conformation. The optimized proton transfer curve as a function of one O-H distance shows a (syn dimer) inflection point and an (anti dimer) minimum, while the MP2 curve shows only a single (anti dimer) minimum. However, the proton transfer energy profiles for a series of fixed R(O...O) distances in the strong H-bond region each show two minima, with the anti dimer always lower in energy, except at R(min) where the minima merge. Two equilibrium symmetric (C2h) structures were also found higher in energy than the asymmetric anti dimer; an anti-anticonformer by 4.1 (SCF) or approximately 1.0 (MP2) kcal/mol, and a syn-syn conformation by 7.1 (SCF) or 3.8 (MP2) kcal/mol. Experimentally, both symmetric type conformers and both the asymmetric syn-syn and (syn) formic acid-(anti) formate anion type dimers have been observed in bicarboxylic acid crystal structures. Comparison of bond lengths and angles between calculated and observed structures for the respective conformation shows very good agreement. The existence of all these conformer combinations experimentally and the small energy differences calculated between them theoretically show the sensitivity of the specific conformation of this strong H-bond system to molecular structure, environment, and level of theoretical treatment. C1 NATL INST STAND & TECHNOL,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. RP BASCH, H (reprint author), BAR ILAN UNIV,DEPT CHEM,IL-52100 RAMAT GAN,ISRAEL. NR 32 TC 32 Z9 32 U1 3 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 2 PY 1991 VL 113 IS 1 BP 95 EP 101 DI 10.1021/ja00001a016 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA ER082 UT WOS:A1991ER08200016 ER PT J AU FERRAIOLO, D FERRAIOLO, K AF FERRAIOLO, D FERRAIOLO, K GP NIST, NATL COMP SECUR CTR TI ANOTHER FACTOR IN DETERMINING SECURITY REQUIREMENTS FOR TRUSTED COMPUTER-APPLICATIONS SO 14TH NATIONAL COMPUTER SECURITY CONFERENCE - INFORMATION SYSTEMS SECURITY: REQUIREMENTS & PRACTICES, PROCEEDINGS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 14th National Computer Security Conference - Information Systems Security: Requirements and Practices CY OCT 01-04, 1991 CL WASHINGTON, DC SP NIST, NATL COMP SECUR CTR C1 NIST,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL INST STANDARDS & TECHNOLOGY PI BOULDER PA 325 BROADWAY, BOULDER, CO 80303-3328 PY 1991 BP 37 EP 44 PG 8 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BA51M UT WOS:A1991BA51M00005 ER PT J AU KUHN, DR AF KUHN, DR GP NIST, NATL COMP SECUR CTR TI PREDICATE DIFFERENCES AND THE ANALYSIS OF DEPENDENCIES IN FORMAL SPECIFICATIONS SO 14TH NATIONAL COMPUTER SECURITY CONFERENCE - INFORMATION SYSTEMS SECURITY: REQUIREMENTS & PRACTICES, PROCEEDINGS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 14th National Computer Security Conference - Information Systems Security: Requirements and Practices CY OCT 01-04, 1991 CL WASHINGTON, DC SP NIST, NATL COMP SECUR CTR C1 NATL INST STAND & TECHNOL,COMP SYST LAB,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL INST STANDARDS & TECHNOLOGY PI BOULDER PA 325 BROADWAY, BOULDER, CO 80303-3328 PY 1991 BP 436 EP 445 PG 10 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BA51M UT WOS:A1991BA51M00043 ER PT J AU TANK, RC CARINO, NJ AF TANK, RC CARINO, NJ TI RATE-CONSTANT FUNCTIONS FOR STRENGTH DEVELOPMENT OF CONCRETE SO ACI MATERIALS JOURNAL LA English DT Article DE CONCRETES; CONSTRUCTION; EQUIVALENT-AGE; MATURITY; MODELS; MORTARS (MATERIAL); RATE CONSTANT; STRENGTH; TEMPERATURE AB The rate constant for strength development of a particular concrete mixture is the initial slope of the relative strength-versus-age curve at constant temperature curing. The form of the rate constant versus temperature function is needed to describe the combined effects of time and temperature on strength development. This study investigates the relationship between the rate constant and curing temperature. Based on strength gain data for concrete and mortar specimens made with Type I cement and cured at 10, 23, and 40 C (50, 73, and 104 F), the following conclusions are drawn: (1) strength gain can be represented by a three-parameter hyperbolic function; (2) the rate constant is a nonlinear function of curing temperature and a simple exponential function describes this relationship; (3) tests of appropriate mortar specimens provide the information needed to predict relative strength development of the corresponding concrete; and (4) the proposed rate constant model accurately describes the development of relative strength as a function of the equivalent age. C1 NATL INST STAND & TECHNOL,BETHESDA,MD. RP TANK, RC (reprint author), NARMADA HYDRO POWER PROJECT,GUJARAT,INDIA. NR 23 TC 55 Z9 57 U1 0 U2 4 PU AMER CONCRETE INST PI FARMINGTON HILLS PA 38800 INTERNATIONAL WAY, COUNTRY CLUB DRIVE, PO BOX 9094, FARMINGTON HILLS, MI 48333-9094 SN 0889-325X J9 ACI MATER J JI ACI Mater. J. PD JAN-FEB PY 1991 VL 88 IS 1 BP 74 EP 83 PG 10 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA EX081 UT WOS:A1991EX08100011 ER PT J AU TODD, P PRETLOW, TG AF TODD, P PRETLOW, TG TI SEPARATION OF LIVING CELLS SO ACS SYMPOSIUM SERIES LA English DT Review ID ELECTROPHORETIC SEPARATION; 2-PHASE SYSTEMS; FLOW-CYTOMETRY; PROTEINS; PARTITION; TISSUES AB There are several reasons for isolating subpopulations of living cells, including biochemical study, product analysis in non-clonogenic cells, selection of fused cells, isolation of rare cell types for cloning, preparation of pure cells for transplantation, and bioreactor maintenance. Methods for separating cells include flow sorting, sedimentation, biphasic extraction, field-flow fractionation, affinity methods, magnetically enhanced affinity methods, and electrophoresis. Each method can be considered in terms of its resolution, purity, gentleness, convenience and cost. Recent advances in each of these methods improves its utility in routine cell-separation practice and its potential for scale-up. C1 CASE WESTERN RESERVE UNIV, DEPT PATHOL, CLEVELAND, OH 44106 USA. RP TODD, P (reprint author), NATL INST STAND & TECHNOL, CTR CHEM TECHNOL, 325 BROADWAY 831 02, BOULDER, CO 80303 USA. NR 75 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0097-6156 J9 ACS SYM SER JI ACS Symp. Ser. PY 1991 VL 464 BP 1 EP 24 PG 24 WC Chemistry, Multidisciplinary SC Chemistry GA FX574 UT WOS:A1991FX57400001 ER PT J AU TODD, P AF TODD, P TI COMPARISON OF METHODS OF PREPARATIVE CELL ELECTROPHORESIS SO ACS SYMPOSIUM SERIES LA English DT Review ID CONTINUOUS-FLOW ELECTROPHORESIS; DENSITY GRADIENT ELECTROPHORESIS; SEPARATION; SURFACE; CHARGE; SEDIMENTATION; POPULATIONS; DIFFUSION; PARTICLES; TISSUES AB In the electrophoretic separation of macromolecules, resolution, purity and yield establish the merits of a separation method. In the separation of living cells by electrophoresis, additional significant criteria include viability, capacity, convenience and cost, as the method must also be acceptable to cell biologists, nondestructive to living cells and in free solution. These demands lead to the following quantitative characteristics of methods of cell electrophoresis: separation (resolution), purity, capacity, product viability, convenience and capital cost. Thirteen different methods of electrophoretic cell separation were compared on the basis of these six criteria using a relative scale of 0 to 4. The methods compared were free zone electrophoresis, density gradient electrophoresis, ascending vertical electrophoresis, re-orienting density gradient electrophoresis, free-flow electrophoresis, agarose sol electrophoresis, low-gravity electrophoresis, continuous flow low-gravity electrophoresis, rotating annular electrophoresis, density-gradient isoelectric focusing, free flow isoelectric focusing, stable flow free boundary electrophoresis, and continuous magnetic belt electrophoresis. In each case the sum of the six scores provides an overall "figure of merit"; however, no method rates a perfect score of 24. While quantitative trade-offs, such as resolution for capacity and vice versa, impose technical limitations on each method, lack of convenience is one of the most significant factors in the failure of cell electrophoresis to become a widely popular method. RP TODD, P (reprint author), NATL INST STAND & TECHNOL, CTR CHEM TECHNOL, 325 BROADWAY 83102, BOULDER, CO 80303 USA. NR 98 TC 0 Z9 0 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0097-6156 J9 ACS SYM SER JI ACS Symp. Ser. PY 1991 VL 464 BP 216 EP 255 PG 40 WC Chemistry, Multidisciplinary SC Chemistry GA FX574 UT WOS:A1991FX57400015 ER PT J AU IYENGAR, GV AF IYENGAR, GV TI THE NEED FOR MULTIDISCIPLINARY APPROACHES IN BIOLOGICAL TRACE-ELEMENT RESEARCH SO ACS SYMPOSIUM SERIES LA English DT Review ID SAMPLE PREPARATION; REFERENCE VALUES; HEALTH AB Biological Trace Element Research (BTER) is a multidisciplinary science and directing research in this field requires a combination of both biological insight and analytical awareness. Quite frequently, the complexities involved here necessitate the use of a variety of scientific talents and a combination of several analytical techniques. For example, some of the special difficulties can be visualized in meeting the requirements of a "total" quality control in the overall context of a BTER investigation. These include experimental design, collection of biologically and analytically "valid" samples, the ability to carry out accurate analytical measurements on those specimens, and a proper evaluation of the analytical data (including data interpretation). Therefore, it follows that a team approach ensuring the required multidisciplinary interactions is a crucial component in any BTER endeavor. RP IYENGAR, GV (reprint author), NATL INST STAND & TECHNOL,REACTOR BLDG 235,B125,GAITHERSBURG,MD 20899, USA. NR 31 TC 5 Z9 5 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0097-6156 J9 ACS SYM SER PY 1991 VL 445 BP 1 EP 13 PG 13 WC Chemistry, Multidisciplinary SC Chemistry GA EV292 UT WOS:A1991EV29200001 ER PT J AU CURRIE, LA AF CURRIE, LA TI THE IMPORTANCE OF CHEMOMETRICS IN BIOMEDICAL MEASUREMENTS SO ACS SYMPOSIUM SERIES LA English DT Review AB Chemometrics as a discipline blends modern mathematical and statistical techniques with chemical knowledge for the design, control, and evaluation of chemical measurements. For complex systems, such as those involving biomedical trace element research, the multidisciplinary efforts toward problem formulation and measurement process design and evaluation can be substantially aided by exploratory chemometric approaches. Following a brief overview of potential chemometrics contributions primary attention is given to exploratory multivariate data analysis techniques, which can capture the essence of a complex data set in a few, visualizable dimensions. Such techniques are appropriate because nuclear-related measurements, quality control samples and data, global dietary intakes, and biological compositions all comprise multiple chemical species, frequently exhibiting correlated behavior. Applications of some of the more powerful techniques, such as principal component factor analysis, are illustrated by multivariable interlaboratory quality control, assessment of pollutant origins, and exploration of daily dietary intake data. RP CURRIE, LA (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 23 TC 4 Z9 4 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0097-6156 J9 ACS SYM SER PY 1991 VL 445 BP 74 EP 100 PG 27 WC Chemistry, Multidisciplinary SC Chemistry GA EV292 UT WOS:A1991EV29200006 ER PT J AU DEVOE, JR AF DEVOE, JR TI ESTABLISHING QUALITY MEASUREMENTS FOR INORGANIC ANALYSIS OF BIOMATERIALS SO ACS SYMPOSIUM SERIES LA English DT Review AB While there have been a number of excellent studies correlating the effects of trace element concentrations in biomaterials with a number of diseases and other health related processes, the inconsistencies of quantitative analytical data still limit progress. It is suggested that a well integrated system of laboratories that is dedicated to analytical chemistry quality assurance can provide an interlaboratory structure that will improve the quality of the measurements. Quantitative measurement of the elemental-bound compound appears to be greatly needed, and significant effort needs to be expended in this most difficult area. Progress can be greatly enhanced by including the analytical chemist in the biomedical research team. RP DEVOE, JR (reprint author), NATL INST STANDARDS & TECHNOL,CTR ANALYT CHEM,DIV INORGAN ANALYT RES,GAITHERSBURG,MD 20899, USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0097-6156 J9 ACS SYM SER PY 1991 VL 445 BP 101 EP 106 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA EV292 UT WOS:A1991EV29200007 ER PT J AU STONE, SF ZEISLER, R GORDON, GE VISCIDI, RP CERNY, EH AF STONE, SF ZEISLER, R GORDON, GE VISCIDI, RP CERNY, EH TI TRACE-ELEMENTS ASSOCIATED WITH PROTEINS - NEUTRON-ACTIVATION ANALYSIS COMBINED WITH BIOLOGICAL ISOLATION TECHNIQUES SO ACS SYMPOSIUM SERIES LA English DT Review AB Combinations of biological techniques with neutron activation analysis (NAA) can be employed for protein quantification in biological samples. A protein of interest can be isolated physically by a high resolution separation technique such as polyacrylamide gel electrophoresis (PAGE) or by an immunochemical technique, such as a specific antibody-antigen reaction. NAA is then used for quantification of the isolated protein by determining either an element that is structurally intrinsic, or one that has been introduced as a label. An example of the first method is the determination of phosphoproteins by PAGE-NAA. This method is discussed and results for two phosphoproteins, alpha-casein and phosvitin, are presented for several materials, including an alpha-casein concentration of 26 mg/mL in low-fat milk. The second method presented is an immunoassay with a colloidal gold tag and detection by NAA. C1 JOHNS HOPKINS UNIV,SCH MED,DEPT PEDIAT,EUDOWOOD DIV INFECT DIS,BALTIMORE,MD 21205. UNIV MARYLAND,DEPT CHEM & BIOCHEM,COLLEGE PK,MD 20742. UNIV GENEVA,FONDAT RECH MED,CH-1211 GENEVA 4,SWITZERLAND. RP STONE, SF (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 12 TC 4 Z9 4 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0097-6156 J9 ACS SYM SER PY 1991 VL 445 BP 265 EP 277 PG 13 WC Chemistry, Multidisciplinary SC Chemistry GA EV292 UT WOS:A1991EV29200021 ER PT J AU SMITH, DB MOODIE, LV HOWARD, BA SHAFFER, LR BACKLUND, P AF SMITH, DB MOODIE, LV HOWARD, BA SHAFFER, LR BACKLUND, P TI COORDINATING EARTH OBSERVATIONS FROM SPACE - TOWARD A GLOBAL EARTH OBSERVING SYSTEM SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 41ST INTERNATIONAL ASTRONAUTICAL FEDERATION CONGRESS : SPACE FOR PEACE AND PROGRESS CY OCT 08-12, 1990 CL DRESDEN, GER DEM REP AB The paper develops the rationale for coordination of Earth observation missions among national and regional agencies to overcome resource limitations, avoid duplication of effort, and make a significant contribution to global change monitoring and assessment. A global Earth observing system must involve all agencies with programmatic and funding responsibility and must be responsive both to scientific inputs and user needs. The paper briefly examines the objectives, current activities, and the linkages among existing Earth observation coordination groups. It advocates the need for a more effective forum for developing consensus across the whole spectrum of Earth and environmental observations satellite missions and proposes the strengthening of the Committee on Earth Observations Satellites (CEOS), a coordination group created as a result of the Group of Seven Economic Summit's Panel of Experts on Remote Sensing from Space. CEOS should be restructured to include representation of international scientific and intergovernmental user organizations and should develop formal linkages to other existing satellite coordination groups. A revitalized CEOS should focus on collaboration in the development and operation of research and operational missions, the sharing of data to assist in global change decision-making, and the construction of international data networks to facilitate global change data management. RP SMITH, DB (reprint author), NOAA,WASHINGTON,DC 20230, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PY 1991 VL 24 BP 83 EP 88 DI 10.1016/0094-5765(91)90154-W PG 6 WC Engineering, Aerospace SC Engineering GA FP763 UT WOS:A1991FP76300009 ER PT J AU SALTMAN, RG AF SALTMAN, RG TI COMPUTERIZED VOTING SO ADVANCES IN COMPUTERS LA English DT Article RP SALTMAN, RG (reprint author), NATL INST STAND & TECHNOL,NATL COMP SYST LAB,GAITHERSBURG,MD 20899, USA. NR 33 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0065-2458 J9 ADV COMPUT JI Adv. Comput. PY 1991 VL 32 BP 255 EP 305 PG 51 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA GM718 UT WOS:A1991GM71800005 ER PT B AU WALTER, PJ KINGSTON, HM SETTLE, FA PLEVA, MA BUOTE, W CHRISTO, J AF WALTER, PJ KINGSTON, HM SETTLE, FA PLEVA, MA BUOTE, W CHRISTO, J BE STRIMAITIS, JR LITTLE, JN TI AUTOMATED INTELLIGENT CONTROL OF MICROWAVE SAMPLE PREPARATION SO ADVANCES IN LABORATORY AUTOMATION ROBOTICS, VOL 7 SE ADVANCES IN LABORATORY AUTOMATION ROBOTICS LA English DT Proceedings Paper CT 8TH INTERNATIONAL SYMP ON LABORATORY ROBOTICS CY SEP 16-19, 1990 CL BOSTON, MA RP WALTER, PJ (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,DIV INORGAN ANALYT RES,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ZYMARK CORP PI HOPKINTON PA HOPKINTON BN 0-931565-06-5 J9 ADV LAB AUT PY 1991 BP 405 EP 416 PG 12 WC Energy & Fuels; Medical Laboratory Technology; Pharmacology & Pharmacy SC Energy & Fuels; Medical Laboratory Technology; Pharmacology & Pharmacy GA BT90W UT WOS:A1991BT90W00026 ER PT J AU MEYERS, TP BALDOCCHI, DD AF MEYERS, TP BALDOCCHI, DD TI THE BUDGETS OF TURBULENT KINETIC-ENERGY AND REYNOLDS STRESS WITHIN AND ABOVE A DECIDUOUS FOREST SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID ORDER CLOSURE-MODEL; PLANT CANOPIES; FLOW; VEGETATION; WIND AB Mean turbulence statistics obtained within and above a deciduous forest are used to examine the components in the budget equations for turbulent kinetic energy (TKE) and tangential shear stress. Comparisons from the measurements are made with predictions from a higher-order closure model for canopy flow. Wake-generated turbulence was found to exceed shear-produced turbulence in all but the upper level of the canopy. Beneath the tree crowns, turbulent transport was the dominant source of TKE and tangential shear stress. Below approximately 75% of the canopy height, the magnitude of all the TKE and shear stress budget components is small compared with values above this height, and the vertical gradients of second-and third-order moments are small. The turbulence statistics observed within the deciduous forest are remarkably similar to that observed within a tropical forest, which has a similar distribution of leaf area. When compared with results from experiments conducted in other canopies, the importance of the quantity and vertical distribution of the plant area in determining the turbulence structure is reinforced. RP MEYERS, TP (reprint author), NOAA,AIR RESOURCES LABS,DIV ATMOSPHER TURBULENCE & DIFFUS,POB 2456,OAK RIDGE,TN 37830, USA. RI Baldocchi, Dennis/A-1625-2009; Meyers, Tilden/C-6633-2016 OI Baldocchi, Dennis/0000-0003-3496-4919; NR 27 TC 45 Z9 45 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD JAN PY 1991 VL 53 IS 3 BP 207 EP 222 DI 10.1016/0168-1923(91)90058-X PG 16 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA EX988 UT WOS:A1991EX98800004 ER PT J AU CARASSO, AS AF CARASSO, AS TI PROBE WAVE-FORMS AND THE RECONSTRUCTION OF STRUCTURAL DYNAMIC GREENS-FUNCTIONS SO AIAA JOURNAL LA English DT Article ID NETWORKS AB Experimental identification of dynamic behavior in linear structural systems can be achieved by exciting the structure with a specifically synthesized pulse, and reconstructing the relevant dynamic Green's function by deconvolution of the measured response. The reconstruction procedure involves the solution of an ill-posed integral equation in the presence of noise. This paper underlines the rich variety of infinitely divisible pulse shapes that may be used while still retaining a tractable deconvolution problem. Flexibility in pulse shape is necessary to allow for possible perturbations caused by interfacing devices that convert electrical voltages into mechanical forces. A numerical experiment, using synthetic noisy data, shows that the reconstruction procedure remains effective even when the probe waveform deviates strongly from the preferred unimodal shape. A dispersive structural netweork that may be representative of a large space structure is used as an illustrative example. RP CARASSO, AS (reprint author), NATL INST STAND & TECHNOL,CTR COMP & APPL MATH,GAITHERSBURG,MD 20899, USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD JAN PY 1991 VL 29 IS 1 BP 114 EP 118 DI 10.2514/3.10552 PG 5 WC Engineering, Aerospace SC Engineering GA EY063 UT WOS:A1991EY06300015 ER PT J AU FORNEY, KA LEETE, AJ LINDBURG, DG AF FORNEY, KA LEETE, AJ LINDBURG, DG TI A BAR CODE SCORING SYSTEM FOR BEHAVIORAL-RESEARCH SO AMERICAN JOURNAL OF PRIMATOLOGY LA English DT Note DE PORTABLE COMPUTER; BEHAVIOR; DATA COLLECTION AB A data collection method using lap-top computers and bar codes was developed and used in behavioral research. The studies involved several common sampling methods and a variety of study subjects. Advantages and restrictions of the system are discussed. Overall, we found bar code technology to increase both efficiency and accuracy of behavioral data collection. C1 ZOOL SOC SAN DIEGO,POB 551,SAN DIEGO,CA 92112. NATL MARINE FISHERIES SERV,SW FISHERIES CTR,LA JOLLA,CA. US FISH & WILDLIFE SERV,SO CALIF FIELD OFF,VENTURA,CA. NR 6 TC 2 Z9 2 U1 0 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0275-2565 J9 AM J PRIMATOL JI Am. J. Primatol. PY 1991 VL 23 IS 2 BP 127 EP 135 DI 10.1002/ajp.1350230206 PG 9 WC Zoology SC Zoology GA EU709 UT WOS:A1991EU70900005 ER PT J AU AUSTER, PJ MALATESTA, RJ LAROSA, SC AF AUSTER, PJ MALATESTA, RJ LAROSA, SC TI MICROHABITAT USE BY CONTINENTAL-SLOPE MEGAFAUNA SO AMERICAN ZOOLOGIST LA English DT Meeting Abstract C1 UNIV CONNECTICUT,NOAA,NATL UNDERSEA RES,GROTON,CT. NR 0 TC 1 Z9 1 U1 0 U2 1 PU AMER SOC ZOOLOGISTS PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0003-1569 J9 AM ZOOL JI Am. Zool. PY 1991 VL 31 IS 5 BP A127 EP A127 PG 1 WC Zoology SC Zoology GA GV285 UT WOS:A1991GV28500504 ER PT J AU DEWAR, H GRAHAM, JB BRILL, RW AF DEWAR, H GRAHAM, JB BRILL, RW TI PHYSIOLOGICAL THERMOREGULATION IN THE YELLOWFIN TUNA, THUNNUS-ALBACARES SO AMERICAN ZOOLOGIST LA English DT Meeting Abstract C1 HONOLULU LAB,NMFS,HONOLULU,HI. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093. NR 0 TC 0 Z9 0 U1 0 U2 4 PU AMER SOC ZOOLOGISTS PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0003-1569 J9 AM ZOOL JI Am. Zool. PY 1991 VL 31 IS 5 BP A41 EP A41 PG 1 WC Zoology SC Zoology GA GV285 UT WOS:A1991GV28500158 ER PT J AU DUGUAY, SJ PARK, LK SAMADPOUR, M DICKHOFF, WW AF DUGUAY, SJ PARK, LK SAMADPOUR, M DICKHOFF, WW TI DISTRIBUTION AND EXPRESSION OF SALMON INSULIN-LIKE GROWTH FACTOR-I MESSENGER-RNA - EVIDENCE FOR 3 IGF-I PROHORMONES SO AMERICAN ZOOLOGIST LA English DT Meeting Abstract C1 UNIV WASHINGTON,SEATTLE,WA 98195. NW FISHERIES SCI CTR,SEATTLE,WA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC ZOOLOGISTS PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0003-1569 J9 AM ZOOL JI Am. Zool. PY 1991 VL 31 IS 5 BP A22 EP A22 PG 1 WC Zoology SC Zoology GA GV285 UT WOS:A1991GV28500081 ER PT J AU PLISETSKAYA, EM MOON, TW LARSEN, DA DICKHOFF, WW AF PLISETSKAYA, EM MOON, TW LARSEN, DA DICKHOFF, WW TI VIRTUAL ABSENCE OF LIVER-GLYCOGEN IN FEEDING SMOLTS OF ATLANTIC SALMON (SALMO-SALAR) IN SEAWATER SO AMERICAN ZOOLOGIST LA English DT Meeting Abstract C1 UNIV WASHINGTON,NW FISHERIES SCI CTR,SEATTLE,WA 98195. UNIV OTTAWA,OTTAWA K1N 6N5,ONTARIO,CANADA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC ZOOLOGISTS PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0003-1569 J9 AM ZOOL JI Am. Zool. PY 1991 VL 31 IS 5 BP A55 EP A55 PG 1 WC Zoology SC Zoology GA GV285 UT WOS:A1991GV28500213 ER PT J AU RASBERRY, SD AF RASBERRY, SD TI REFERENCE MATERIALS FOR ANALYTICAL-CHEMISTRY SO ANALUSIS LA English DT Article RP RASBERRY, SD (reprint author), NATL INST STAND & TECHNOL,OFF MEASUREMENT SERV,ROOM B-354,PHYS BLDG,GAITHERSBURG,MD 20899, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU EDITIONS SCIENTIFIQUES ELSEVIER PI PARIS CEDEX 15 PA 141 RUE JAVEL, 75747 PARIS CEDEX 15, FRANCE SN 0365-4877 J9 ANALUSIS JI Analusis PD JAN PY 1991 VL 19 IS 1 BP I35 EP I37 PG 3 WC Chemistry, Analytical SC Chemistry GA EZ172 UT WOS:A1991EZ17200009 ER PT J AU SONG, JF VORBURGER, TV AF SONG, JF VORBURGER, TV TI STYLUS PROFILING AT HIGH-RESOLUTION AND LOW FORCE SO APPLIED OPTICS LA English DT Article DE ATOMIC FORCE MICROSCOPE; CALIBRATION; DIAMOND; GRATING; PIEZOELECTRIC; PROFILING; RESOLUTION; ROUGHNESS; STYLUS; SURFACE ID SCANNING TUNNELING MICROSCOPY; OPTICAL-SURFACES; STATISTICAL PROPERTIES; INSTRUMENT AB This paper describes experimental work to improve the lateral resolution of stylus instruments. Our efforts involve (1) use of a fine stylus, (2) low stylus load, (3) high magnification in the lateral direction, and (4) specimens with fine surface structure by which the lateral resolution of stylus instruments could be detected. By using styli with tip widths between 0.05 and 0.15-mu-m, a stylus load of 0.6-1.2 X 10(-6)-N (0.06-0.12-mgf), and a piezostage for lateral displacement, we detected 0.05-0.15-mu-m lateral resolution on the surfaces of different kinds of specimens. To get a high lateral resolution, the most important consideration is a fine stylus with small tip size. RP SONG, JF (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 30 TC 37 Z9 41 U1 1 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JAN 1 PY 1991 VL 30 IS 1 BP 42 EP 50 PG 9 WC Optics SC Optics GA ER772 UT WOS:A1991ER77200006 PM 20581945 ER PT J AU HORN, RG SMITH, DT AF HORN, RG SMITH, DT TI ANALYTIC SOLUTION FOR THE 3-LAYER MULTIPLE BEAM INTERFEROMETER SO APPLIED OPTICS LA English DT Article ID SURFACE FORCES; FILMS; MICA AB We present a simple analytic solution for the condition of constructive interference for light transmitted through an interferometer incorporating three ideally transparent layers of arbitrary thickness and refractive index. We also consider the effect of adding two metallic coatings to the outer surfaces of the interferometer and give empirical expressions for the associated phase changes for silver coatings on silica, sapphire, and mica substrates. A particular application to fringes of equal chromatic order can be utilized to obtain precise measurements of the thickness of extremely thin films sandwiched between two substrates. RP NATL INST STAND & TECHNOL, DIV CERAM, GAITHERSBURG, MD 20899 USA. RI Horn, Roger/L-2782-2013; Smith, Douglas/I-4403-2016 OI Smith, Douglas/0000-0002-9358-3449 NR 20 TC 47 Z9 47 U1 0 U2 7 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 JAN 1 PY 1991 VL 30 IS 1 BP 59 EP 65 PG 7 WC Optics SC Optics GA ER772 UT WOS:A1991ER77200008 PM 20581947 ER PT J AU ENG, G TIERNEY, EJ OLSON, GJ BRINCKMAN, FE BELLAMA, JM AF ENG, G TIERNEY, EJ OLSON, GJ BRINCKMAN, FE BELLAMA, JM TI TOTAL SURFACE-AREAS OF GROUP IVA ORGANOMETALLIC COMPOUNDS - PREDICTORS OF TOXICITY TO ALGAE AND BACTERIA SO APPLIED ORGANOMETALLIC CHEMISTRY LA English DT Article DE ORGANOTIN; ORGANOLEAD; ORGANOSILICON; ORGANOGERMANIUM; TOXICITY; TOTAL SURFACE AREA (TSA); QUANTITATIVE STRUCTURE ACTIVITY RELATIONSHIPS (QSAR); MOLECULAR TOPOLOGY; GROUP IVA ORGANOMETALS; ESCHERICHIA-COLI; SELENASTRUM-CAPRICORNUTUM ID PARAMETERS AB There is a high correlation between molecular surface area (TSA) of triorganotin and triorganolead compounds and their toxicity towards a bacterium (Escherichia coli) and an alga (Selenastrum capricornutum). Parallel attempts to correlate other Group IVA organometals incorporating silicon or germanium were unsuccessful. It was further demonstrated, however, that a high correlation was obtainable between certain series of compounds with the same organic substituent but different metal centers involving all Group IVA elements. In both instances, the inability to obtain a quantitative structure-activity relationship (QSAR) for all systems studied appears to be a function of the solubility of the compounds. While organotin TSA values have been found to correlate well with their toxicities toward various organisms, this study clearly suggests that this type of QSAR can be readily extended to include other organometal systems, provided that there is no solubility problem and the toxicity is a function of the hydrophobicity of the organometal compounds. C1 UNIV DIST COLUMBIA,DEPT CHEM,WASHINGTON,DC 20005. UNIV MARYLAND,DEPT CHEM & BIOCHEM,COLLEGE PK,MD 20742. NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 17 TC 26 Z9 26 U1 0 U2 6 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0268-2605 J9 APPL ORGANOMET CHEM JI Appl. Organomet. Chem. PD JAN-FEB PY 1991 VL 5 IS 1 BP 33 EP 37 DI 10.1002/aoc.590050104 PG 5 WC Chemistry, Applied; Chemistry, Inorganic & Nuclear SC Chemistry GA EW378 UT WOS:A1991EW37800003 ER PT J AU DESROSIERS, MF WILSON, GL HUNTER, CR HUTTON, DR AF DESROSIERS, MF WILSON, GL HUNTER, CR HUTTON, DR TI ESTIMATION OF THE ABSORBED DOSE IN RADIATION-PROCESSED FOOD .1. TEST OF THE EPR RESPONSE FUNCTION BY A LINEAR-REGRESSION ANALYSIS SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID ELECTRON-SPIN-RESONANCE; FREE-RADICALS; IRRADIATED FOOD; SPECTROSCOPY; DOSIMETRY; BONES AB Free radicals produced in chicken bone tissue by Cs-137 gamma-rays were measured using electron paramagnetic resonance spectroscopy. The yield of radicals was found to be proportional to the absorbed dose. Additive re-irradiation of previously irradiated bones is the basis of a method to estimate the absorbed dose in radiation-processed foods. The ability of the method to provide accurate dose assessments for a range of doses (0.5-7.4 kGy) is tested here. A linear fit to the data yields reasonable dose estimates for bone irradiated < 2 kGy, but fails at the higher doses using a linear approximation to the dose response. These data and their implications are discussed. C1 MONASH UNIV,DEPT PHYS,CLAYTON,VIC 3168,AUSTRALIA. MONASH UNIV,DEPT ANAT,CLAYTON,VIC 3168,AUSTRALIA. RP DESROSIERS, MF (reprint author), NATL INST STAND & TECHNOL,CTR RADIAT RES,GAITHERSBURG,MD 20899, USA. NR 18 TC 46 Z9 48 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PY 1991 VL 42 IS 7 BP 613 EP 616 PG 4 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA FW355 UT WOS:A1991FW35500003 ER PT J AU DESROSIERS, MF AF DESROSIERS, MF TI ESTIMATION OF THE ABSORBED DOSE IN RADIATION-PROCESSED FOOD .2. TEST OF THE EPR RESPONSE FUNCTION BY AN EXPONENTIAL FITTING ANALYSIS SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID RESONANCE SPECTROSCOPY; IRRADIATED FOOD; DOSIMETRY; BONE AB The use of electron paramagnetic resonance spectroscopy to accurately evaluate the absorbed dose to radiation-processed bones (and thus meats) is examined. Additive re-irradiation of the bone produces a reproducible dose response function which can be used to evaluate the initial dose by back-extrapolation. It was found that an exponential fit (vs linear or polynomial) to the data provides improved accuracy of the estimated dose. These data as well as the protocol for the additive dose method are presented. RP DESROSIERS, MF (reprint author), NATL INST STAND & TECHNOL,CTR RADIAT RES,GAITHERSBURG,MD 20899, USA. NR 8 TC 50 Z9 51 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PY 1991 VL 42 IS 7 BP 617 EP 619 PG 3 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA FW355 UT WOS:A1991FW35500004 ER PT J AU COURSEY, BM CESSNA, J GARCIATORANO, E GOLAS, DB MALONDA, AG GRAY, DH HOPPES, DD ARCOS, JML MARTINCASALLO, MT SCHIMA, FJ UNTERWEGER, MP AF COURSEY, BM CESSNA, J GARCIATORANO, E GOLAS, DB MALONDA, AG GRAY, DH HOPPES, DD ARCOS, JML MARTINCASALLO, MT SCHIMA, FJ UNTERWEGER, MP TI THE STANDARDIZATION AND DECAY SCHEME OF RE-186 SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID COUNTING EFFICIENCY; PROGRAM AB Rhenium-186 has been standardized for activity by the CIEMAT/NIST method of 4-pi-beta-liquid-scintillation efficiency tracing with tritium, with an uncertainty (equivalent to 1 SD) of 1.61%. Half-life measurements with a pressurized ionization chamber give a T1/2 = 89.25 +/- 0.07 h. Photon emission rates were measured with semiconductor detectors, and the probability of emission of the principal gamma-ray at 137 keV was found to be P7 = 0.0945 +/- 0.0016. C1 CTR INVEST ENERGET MEDIOAMBIENTALES & TECHNOL,INST INVEST BAS,E-28040 MADRID,SPAIN. US COUNCIL ENERGY AWARENESS,WASHINGTON,DC 20006. RP COURSEY, BM (reprint author), NATL INST STAND & TECHNOL,CTR RADIAT RES,DIV IONIZING RADIAT,GAITHERSBURG,MD 20899, USA. OI Garcia-Torano, Eduardo/0000-0002-5930-475X NR 17 TC 25 Z9 25 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PY 1991 VL 42 IS 9 BP 865 EP 869 PG 5 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA GF251 UT WOS:A1991GF25100016 ER PT J AU HOPPES, DD HUTCHINSON, JMR AF HOPPES, DD HUTCHINSON, JMR TI INTERNATIONAL-COMMITTEE-FOR-RADIONUCLIDE-METROLOGY - GUIDELINES-FOR-INTERNATIONAL-ACCEPTANCE-OF-RADIOACTIVITY-CALIBRATION-SOU RCES SO APPLIED RADIATION AND ISOTOPES LA English DT Note C1 NATL INST STAND & TECHNOL,CTR RADIAT RES,GAITHERSBURG,MD 20899. NR 5 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PY 1991 VL 42 IS 9 BP 893 EP 897 PG 5 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA GF251 UT WOS:A1991GF25100022 ER PT J AU BERGER, MJ AF BERGER, MJ TI DIFFERENCES IN THE MULTIPLE-SCATTERING OF POSITRONS AND ELECTRONS SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT SYMP ON THE PHYSICS OF ELECTRON TRANSPORT CY APR 02-03, 1990 CL NIST, GAITHERSBURG, MD SP US DOE, OFF HLTH & ENVIRONM RES HO NIST AB After a brief review of differences between the scattering cross sections for electrons and positrons, results are presented on the transmission and reflection of these particles by foils. These results were obtained with the Monte Carlo code ETRAN, which takes into account positron-electron differences of stopping powers and elastic-scattering cross sections. The principal output of the calculations consists of number and energy transmission and reflection coefficients for electrons and positrons. A few results are also shown pertaining to differences of energy spectra and angular distributions of positrons and electrons reflected from thick foils. The calculated transmission coefficients for positrons are greater, and the reflection coefficients smaller, than those for electrons of the same energy. These results are in qualitative agreement with experimental data, but the quantitative agreement is not very close. RP BERGER, MJ (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 39 TC 8 Z9 8 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PY 1991 VL 42 IS 10 BP 905 EP 916 PG 12 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA GL858 UT WOS:A1991GL85800003 ER PT J AU SELTZER, SM AF SELTZER, SM TI ELECTRON PHOTON MONTE-CARLO CALCULATIONS - THE ETRAN CODE SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID ATOMIC-FIELD BREMSSTRAHLUNG; ORBITAL ELECTRONS; PAIR PRODUCTION; NEUTRAL ATOMS; POSITRON; SPECTRA; NUCLEI AB This paper briefly describes the Monte Carlo code ETRAN, developed for the solution of coupled electron-photon transport problems, We focus on the multiple-scattering distributions and underlying cross sections that form the basis of current versions of ETRAN, without details on sampling algorithms or numerical procedures. RP NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 67 TC 120 Z9 121 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PY 1991 VL 42 IS 10 BP 917 EP 941 PG 25 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA GL858 UT WOS:A1991GL85800004 ER PT J AU CASWELL, RS LOEVINGER, R AF CASWELL, RS LOEVINGER, R TI REMARKS ON THE CAREER OF BERGER,MARTIN,J. SO APPLIED RADIATION AND ISOTOPES LA English DT Item About an Individual RP CASWELL, RS (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PY 1991 VL 42 IS 10 BP R13 EP R14 PG 2 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA GL858 UT WOS:A1991GL85800002 ER PT J AU SELTZER, SM INOKUTI, M AF SELTZER, SM INOKUTI, M TI PROCEEDINGS OF THE SYMPOSIUM ON THE PHYSICS OF ELECTRON-TRANSPORT - GAITHERSBURG, MARYLAND, 2-3 APRIL 1990 SO APPLIED RADIATION AND ISOTOPES LA English DT Editorial Material C1 ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439. RP SELTZER, SM (reprint author), NATL INST STAND & TECHNOL,DIV IONIZING RADIAT,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PY 1991 VL 42 IS 10 BP R11 EP R11 PG 1 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA GL858 UT WOS:A1991GL85800001 ER PT J AU KELLY, GE PARK, C BARNETT, JP AF KELLY, GE PARK, C BARNETT, JP BE Geshwiler, M TI USING EMULATORS TESTERS FOR COMMISSIONING EMCS SOFTWARE, OPERATOR TRAINING, ALGORITHM DEVELOPMENT, AND TUNING LOCAL-CONTROL LOOPS SO ASHRAE TRANSACTIONS 1991, VOL 97, PT 1 SE ASHRAE TRANSACTIONS LA English DT Proceedings Paper CT 1991 Winter Meeting of the American-Society-of-Heating-Refrigerating-and-Air-Conditioning-Engineers -Incorporated CY JAN 19-23, 1991 CL NEW YORK, NY SP AMER SOC HEATING REFRIGERATING & AIR CONDITIONING ENGINEERS INC C1 NATL INST STAND & TECHNOL,CTR BLDG TECHNOL,DIV BLDG ENVIRONM,GAITHERSBURG,MD. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER SOC HEATING, REFRIGERATING AND AIR-CONDITIONING ENGS PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 J9 ASHRAE TRAN PY 1991 VL 97 BP 669 EP 678 PN 1 PG 10 WC Construction & Building Technology; Engineering, Mechanical SC Construction & Building Technology; Engineering GA BA38X UT WOS:A1991BA38X00083 ER PT B AU DOMANSKI, PA AF DOMANSKI, PA BE Geshwiler, M TI SIMULATION OF AN EVAPORATOR WITH NONUNIFORM ONE-DIMENSIONAL AIR-DISTRIBUTION SO ASHRAE TRANSACTIONS 1991, VOL 97, PT 1 SE ASHRAE TRANSACTIONS LA English DT Proceedings Paper CT 1991 Winter Meeting of the American-Society-of-Heating-Refrigerating-and-Air-Conditioning-Engineers -Incorporated CY JAN 19-23, 1991 CL NEW YORK, NY SP AMER SOC HEATING REFRIGERATING & AIR CONDITIONING ENGINEERS INC C1 NATL INST STAND & TECHNOL,THERMAL MACHINERY GRP,GAITHERSBURG,MD. NR 0 TC 45 Z9 59 U1 0 U2 1 PU AMER SOC HEATING, REFRIGERATING AND AIR-CONDITIONING ENGS PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 J9 ASHRAE TRAN PY 1991 VL 97 BP 793 EP 802 PN 1 PG 10 WC Construction & Building Technology; Engineering, Mechanical SC Construction & Building Technology; Engineering GA BA38X UT WOS:A1991BA38X00099 ER PT B AU FANNEY, AH BURCH, DM THOMAS, WC MATHENA, LR COLLIVER, D HEDLIN, C SPOLEK, G AF FANNEY, AH BURCH, DM THOMAS, WC MATHENA, LR COLLIVER, D HEDLIN, C SPOLEK, G BE Geshwiler, M TI MEASUREMENTS OF MOISTURE DIFFUSION IN BUILDING-MATERIALS SO ASHRAE TRANSACTIONS 1991, VOL 97, PT 2 SE ASHRAE TRANSACTIONS LA English DT Proceedings Paper CT 1991 Annual Meeting of the American-Society-of-Heating-Refrigerating-and-Air-Conditioning-Engineers -Incorporated CY JUN 22-26, 1991 CL INDIANAPOLIS, IN SP AMER SOC HEATING REFRIGERATING & AIR CONDITIONING ENGINEERS INC C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD. NR 0 TC 6 Z9 7 U1 0 U2 0 PU AMER SOC HEATING, REFRIGERATING AND AIR-CONDITIONING ENGS PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 J9 ASHRAE TRAN PY 1991 VL 97 BP 99 EP 113 PN 2 PG 15 WC Construction & Building Technology; Engineering, Mechanical SC Construction & Building Technology; Engineering GA BA38Y UT WOS:A1991BA38Y00014 ER PT J AU HUANG, PH AF HUANG, PH BE Geshwiler, M TI HUMIDITY MEASUREMENTS AND CALIBRATION STANDARDS SO ASHRAE TRANSACTIONS 1991, VOL 97, PT 2 SE ASHRAE TRANSACTIONS LA English DT Proceedings Paper CT 1991 Annual Meeting of the American-Society-of-Heating-Refrigerating-and-Air-Conditioning-Engineers -Incorporated CY JUN 22-26, 1991 CL INDIANAPOLIS, IN SP AMER SOC HEATING REFRIGERATING & AIR CONDITIONING ENGINEERS INC C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEATING, REFRIGERATING AND AIR-CONDITIONING ENGS PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 J9 ASHRAE TRAN PY 1991 VL 97 BP 298 EP 304 PN 2 PG 7 WC Construction & Building Technology; Engineering, Mechanical SC Construction & Building Technology; Engineering GA BA38Y UT WOS:A1991BA38Y00037 ER PT J AU DOMANSKI, PA AF DOMANSKI, PA BE Geshwiler, M TI RATING OF MIXED, SPLIT, RESIDENTIAL HEAT-PUMPS OPERATING IN THE HEATING MODE SO ASHRAE TRANSACTIONS 1991, VOL 97, PT 2 SE ASHRAE TRANSACTIONS LA English DT Proceedings Paper CT 1991 Annual Meeting of the American-Society-of-Heating-Refrigerating-and-Air-Conditioning-Engineers -Incorporated CY JUN 22-26, 1991 CL INDIANAPOLIS, IN SP AMER SOC HEATING REFRIGERATING & AIR CONDITIONING ENGINEERS INC C1 NATL INST STAND & TECHNOL,DIV BLDG ENVIRONM,GAITHERSBURG,MD. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEATING, REFRIGERATING AND AIR-CONDITIONING ENGS PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 J9 ASHRAE TRAN PY 1991 VL 97 BP 324 EP 330 PN 2 PG 7 WC Construction & Building Technology; Engineering, Mechanical SC Construction & Building Technology; Engineering GA BA38Y UT WOS:A1991BA38Y00041 ER PT J AU KLOTE, JH TAMURA, GT AF KLOTE, JH TAMURA, GT BE Geshwiler, M TI DESIGN OF ELEVATOR SMOKE CONTROL-SYSTEMS FOR FIRE EVACUATION SO ASHRAE TRANSACTIONS 1991, VOL 97, PT 2 SE ASHRAE TRANSACTIONS LA English DT Proceedings Paper CT 1991 Annual Meeting of the American-Society-of-Heating-Refrigerating-and-Air-Conditioning-Engineers -Incorporated CY JUN 22-26, 1991 CL INDIANAPOLIS, IN SP AMER SOC HEATING REFRIGERATING & AIR CONDITIONING ENGINEERS INC C1 NATL INST STAND & TECHNOL,BLDG FIRE PHYS GRP,GAITHERSBURG,MD. NR 0 TC 2 Z9 2 U1 1 U2 2 PU AMER SOC HEATING, REFRIGERATING AND AIR-CONDITIONING ENGS PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 J9 ASHRAE TRAN PY 1991 VL 97 BP 634 EP 642 PN 2 PG 9 WC Construction & Building Technology; Engineering, Mechanical SC Construction & Building Technology; Engineering GA BA38Y UT WOS:A1991BA38Y00077 ER PT J AU DRAKE, SA LINSKY, JL JUDGE, PG ELITZUR, M AF DRAKE, SA LINSKY, JL JUDGE, PG ELITZUR, M TI RADIO-CONTINUUM OBSERVATIONS OF A VARIETY OF COOL STARS SO ASTRONOMICAL JOURNAL LA English DT Article ID CIRCUMSTELLAR DUST SHELLS; MASS-LOSS; RADIATIVE-TRANSFER; VLA OBSERVATIONS; EVOLVED STARS; CARBON STARS; EMISSION; ENVELOPES; VARIABLES; IRC+10216 AB We present radio-continuum observations made at 2 and/or 6 cm of 26 cool stars (F0 and later), including 10 F-K main-sequence stars and 16 F-M giant and supergiant stars. The data were obtained as part of several Very Large Array2 observing programs. 22 of the observed stars were not detected as sources and have typical 3-sigma upper limits of approximately 0.35 mJy at 2 cm and approximately 0.15-0.60 mJy at 6 cm. The failure to detect any of the F-K dwarf stars reconfirms that such stars have intrinsically weak (log L(v) < 13-14 at 6 cm) radio emission, even if they have rotational periods and/or x-ray luminosities that are similar to those of the (radio detected) RS CVn binary systems. The evolved stars that were detected as radio sources include two M giants (g Her and R Lyr) and the infrared carbon star IRC + 10216. The results of this program when combined with those of our previous studies suggest the existence of a discontinuity in the average ionization fractions of the winds of red giants that occurs at about a spectral type of M6 III. This is also the point at which significant dust formation is observed in red giants. Giants earlier than M6 have f(ion) approximately 10(-2), while cooler giants have f(ion) less-than-or-equal-to 10(-4). The radio source associated with IRC + 10216 may be partially resolved at 2 cm; the brightness temperature at 2 cm, assuming that this is the case, is 1920 K. If the source is in fact unresolved, then the "true" brightness temperature must be greater than this. We discuss alternate models for the 2 and 6 cm radio emission of IRC + 10216 and conclude that the 6 cm emission is consistent with free-free emission from an expanding, partially ionized (f(ion) less-than-or-equal-to 10(-4) wind with an ionized mass loss rate of approximately 3 X 10(-9) M- yr-1. C1 UNIV KENTUCKY,DEPT PHYS & ASTRON,LEXINGTON,KY 40506. NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,BOULDER,CO 80309. RP DRAKE, SA (reprint author), ST SYST CORP,4400 FORBES BLVD,LANHAM,MD 20706, USA. NR 34 TC 31 Z9 31 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD JAN PY 1991 VL 101 IS 1 BP 230 EP 236 DI 10.1086/115683 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA EP496 UT WOS:A1991EP49600022 ER PT J AU YAAQUB, RR DAVIES, TD JICKELLS, TD MILLER, JM AF YAAQUB, RR DAVIES, TD JICKELLS, TD MILLER, JM TI TRACE-ELEMENTS IN DAILY COLLECTED AEROSOLS AT A SITE IN SOUTHEAST ENGLAND SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE AEROSOLS; TRACE METALS; NORTH SEA ID LONG-RANGE TRANSPORT; BACKGROUND AEROSOL; FILTER PAPERS; SULFATE; ACIDITY; METALS; SWEDEN; EUROPE; COAST; AIR AB Daily collections of aerosols have been made at a site in southeast England over a 1 year period and the samples analyzed for 13 components including soot carbon, major anions, some major cations and five trace metals (Pb, Cd, Zn, Mn and Ni). The results are consistent with other more limited studies in the southern North Sea and can be used to tentatively identify primary and secondary sources for the components of the aerosol. Elemental ratios for some components derived from anthropogenic sources vary slightly depending on the source region over which the air has recently travelled. Classification of the samples by back trajectory analysis shows that for all components, except those derived from seawater, concentrations are highest in air arriving from the east. This observation is discussed in terms of meteorological control on the transport and deposition of aerosols. Specifically, high pressure over Europe allows the accumulation of pollutants through reduced atmospheric dispersion and limited removal by precipitation. Subsequent long-range transport results in high concentrations of aerosols at the sampling site. By contrast, transport from the west is associated with efficient dispersal and removal processes. C1 UNIV E ANGLIA,SCH ENVIRONM SCI,NORWICH NR4 7TJ,NORFOLK,ENGLAND. BASHAH UNIV,MARINE SCI CTR,BASHAH,IRAQ. AIR RESOURCES LAB,SILVER SPRING,MD. NR 56 TC 69 Z9 70 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PY 1991 VL 25 IS 5-6 BP 985 EP 996 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA FF359 UT WOS:A1991FF35900015 ER PT J AU ROLPH, GD ARTZ, RS AF ROLPH, GD ARTZ, RS TI A PAIRED COMPARISON OF 2 PRECIPITATION CHEMISTRY SITES IN EAST-CENTRAL MISSISSIPPI SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE PRECIPITATION CHEMISTRY; NADP SITING CRITERIA ID ACID PRECIPITATION AB A paired comparison was performed on 2 years of precipitation chemistry data from Meridian and Newton, MS. The Meridian site is in violation of several National Atmospheric Deposition Program siting criteria, whereas the Newton site, 35 km west, is mostly in compliance. The two sites are compared through the use of volume-weighted means, deposition, logarithmic distributions, boxplots, paired t-tests, the nonparametric Wilcoxon test, and a form of linear regression analysis that accounts for cases in which both populations are subject to error. Results indicate Meridian has higher concentrations of all measured ions except NH4+. Elevated NH4+ concentrations at Newton are most likely due to the location of the site in a cattle pasture. Significant differences (95% confidence level) were found for Cl-, Na+, K+, Ca2+ and Mg2+ . SO42- was found to be borderline significant. RP ROLPH, GD (reprint author), NOAA,AIR RESOURCES LAB,SILVER SPRING,MD 20910, USA. RI Artz, Richard/P-6371-2015; Rolph, Glenn/P-6860-2015 OI Artz, Richard/0000-0002-1335-0697; NR 13 TC 1 Z9 1 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PY 1991 VL 25 IS 8 BP 1449 EP 1461 DI 10.1016/0960-1686(91)90004-Q PG 13 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA FP764 UT WOS:A1991FP76400004 ER PT J AU SIEVERING, H BOATMAN, J GALLOWAY, J KEENE, W KIM, Y LURIA, M RAY, J AF SIEVERING, H BOATMAN, J GALLOWAY, J KEENE, W KIM, Y LURIA, M RAY, J TI HETEROGENEOUS SULFUR CONVERSION IN SEA-SALT AEROSOL-PARTICLES - THE ROLE OF AEROSOL WATER-CONTENT AND SIZE DISTRIBUTION SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE SULFATE; SULFUR DIOXIDE; SEA-SALT; AEROSOL PARTICLES; SIZE DISTRIBUTION ID MARINE BOUNDARY-LAYER; NATURAL-WATERS; OXIDATION; SO2; SULFATE; CLOUDS; DEPOSITION; NEARSHORE; H2O2 AB Meteorological and chemical conditions during the July 1988 Bermuda-area sampling appear to have been favorable for conversion of sulfur gases to particulate excess sulfate (XSO4). Observed average XSO4 and SO2 concentrations of 11 and 2.1 nmol m-3, respectively, at 15 m a.s.l. in the marine boundary layer (MBL) upwind of Bermuda, indicate that conversion of SO2 to XSO4, over and above homogeneous conversion, may be necessary to explain the > 5.0 average molar ratio of XSO4 to SO2. Given an observed cloud cover of < 15% over the region and the < 3 nmol m-3 SO2 concentrations observed by aircraft, heterogeneous conversion mechanisms, in addition to cloud conversion of SO2, are necessary to explain the observed 11 nmol XSO4 m-3. Aerosol water content, estimated as a function of particle size distribution plus consideration of SO2 mass transfer for the observed particle size distribution, shows that SO2 was rapidly transferred to the sea-salt aerosol particles. Assuming that aqueous-phase SO2 reaction kinetics within the high pH sea-salt aerosol water are controlled by O3 oxidation, and considering mass-transfer limitations, SO2 conversion to XSO4 in the sea-salt aerosol water occurred at rates of approximately 5% h-1 under the low SO2 concentration, Bermuda-area sampling conditions. All of the 2 nmol XSO4 m-3 associated with sea-salt aerosol particles during low-wind-speed, Bermuda-area sampling can be explained by this conversion mechanism. Higher wind speed, greater aerosol water content and higher SO2 concentration conditions over the North Atlantic are estimated to generate more than 4 nmol XSO4 m-3 by heterogeneous conversion of SO2 in sea-salt aerosol particles. C1 HEBREW UNIV JERUSALEM,DEPT ENVIRONM SCI,JERUSALEM,ISRAEL. UNIV COLORADO,DEPT PHYS,DENVER,CO 80202. NOAA,AIR RESOURCES LAB,AEROSOL RES SECT,BOULDER,CO 80303. UNIV VIRGINIA,DEPT ENVIRONM SCI,CHARLOTTESVILLE,VA 22903. RP SIEVERING, H (reprint author), UNIV COLORADO,CTR ENVIRONM SCI,1200 LARIMER ST,DENVER,CO 80204, USA. RI Galloway, James/C-2769-2013 OI Galloway, James/0000-0001-7676-8698 NR 41 TC 107 Z9 111 U1 2 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PY 1991 VL 25 IS 8 BP 1479 EP 1487 DI 10.1016/0960-1686(91)90007-T PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA FP764 UT WOS:A1991FP76400007 ER PT J AU LURIA, M SIEVERING, H AF LURIA, M SIEVERING, H TI HETEROGENEOUS AND HOMOGENEOUS OXIDATION OF SO2 IN THE REMOTE MARINE ATMOSPHERE SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE SULFUR DIOXIDE; SULFATE AEROSOL; SEA-SALT AEROSOL; HETEROGENEOUS OXIDATION OF SO2 ID DIMETHYL SULFIDE; CHEMICAL MECHANISM; SULFUR-DIOXIDE; ATLANTIC-OCEAN; GAS-PHASE; SULFATE; CONVERSION; TRANSPORT; CHEMISTRY; AEROSOL AB A photochemical computer model was used to simulate production and removal of S-containing species in the remote marine atmosphere. The results of aircraft and shipboard trace gas and aerosol measurements, performed during the 1988 Coordinated Air-Sea Experiment/Western Atlantic Ocean Experiment (CASE/WATOX) were used for the model input. The modeling revealed that homogeneous oxidation can not explain the existence of excess sulfate on large particles. Thus, it must be supplemented by an additional process in order to obtain a balance between sources and sinks of sulfur species. A proposed heterogeneous pathway consisting of SO2 condensation on and oxidation in aerosol particles was tested. With the addition of the heterogeneous processes, and assuming that the rate-determining step is condensation of SO2 on large particles by molecular diffusion, it was possible to simulate the experimentally observed concentrations of all sulfur species. Results show that the upper limit for rate constants (dictated by diffusion theory) was 50-1500 times larger than the rate constants used in the model for the condensation process. The balance between sources and sinks, using this model, requires that nearly 60% of the observed oxidation should occur via the heterogeneous channel at a rate of about 0.015 h-1. The 24h average homogeneous rate was approximately 0.01 h-1. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,CTR ENVIRONM SCI,DENVER,CO 80202. UNIV COLORADO,DEPT PHYS,DENVER,CO 80202. HEBREW UNIV JERUSALEM,DEPT ENVIRONM SCI,IL-91904 JERUSALEM,ISRAEL. RP LURIA, M (reprint author), NOAA,ENVIRONM RES LAB,ATMOSPHER RES LAB,AEROSOL RES SECT,BOULDER,CO 80303, USA. NR 41 TC 61 Z9 63 U1 2 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PY 1991 VL 25 IS 8 BP 1489 EP 1496 DI 10.1016/0960-1686(91)90008-U PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA FP764 UT WOS:A1991FP76400008 ER PT J AU KAHL, JD SCHNELL, RC SHERIDAN, PJ ZAK, BD CHURCH, HW MASON, AS HEFFTER, JL HARRIS, JM AF KAHL, JD SCHNELL, RC SHERIDAN, PJ ZAK, BD CHURCH, HW MASON, AS HEFFTER, JL HARRIS, JM TI PREDICTING ATMOSPHERIC DEBRIS TRANSPORT IN REAL-TIME USING A TRAJECTORY FORECAST MODEL SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE ATMOSPHERIC TRANSPORT; TRAJECTORY; FORECAST AB An experiment is described in which a trajectory forecast model was used in real-time to estimate the transport of debris associated with a large chemical explosion in the south-western U.S. The forecast trajectories were used to vector sampling aircraft into a position favorable for intersecting the debris cloud. The forecasts are evaluated and compared with three independent measures of debris transport: diagnostic trajectories calculated after the experiment using observed wind fields; transport of a tracer balloon; and aircraft measurements of the debris cloud. Trajectory forecasts originating as early as 39 h before the explosion successfully predicted the downwind atmospheric drift pathway of the cloud. The forecast trajectories agreed well with diagnostic trajectories, confirming the high quality of the meteorological forecast data upon which the trajectories are based. The forecast trajectories also proved skilful in predicting real-time atmospheric motion at short notice. The results support our conclusion that forecast trajectory models are valuable tools for vectoring sampling aircraft in long-range atmospheric dispersion experiments and operations. These models should prove useful in the future when real-time estimates of atmospheric transport are needed. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. UNIV CALIF LOS ALAMOS SCI LAB,DIV ISOTOPE & NUCL CHEM,LOS ALAMOS,NM 87545. NOAA,AIR RESOURCES LAB,SILVER SPRING,MD 20910. NOAA,CLIMAT MONITORING & DIAGNOST LAB,BOULDER,CO 80303. RP KAHL, JD (reprint author), UNIV WISCONSIN,DEPT GEOSCI,MILWAUKEE,WI 53201, USA. NR 14 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PY 1991 VL 25 IS 8 BP 1705 EP 1713 DI 10.1016/0960-1686(91)90028-6 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA FP764 UT WOS:A1991FP76400028 ER PT J AU BODHAINE, BA AHLQUIST, NC SCHNELL, RC AF BODHAINE, BA AHLQUIST, NC SCHNELL, RC TI 3-WAVELENGTH NEPHELOMETER SUITABLE FOR AIRCRAFT MEASUREMENT OF BACKGROUND AEROSOL SCATTERING COEFFICIENT SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE NEPHELOMETER; AEROSOL; AEROSOL SCATTERING; AIRCRAFT AEROSOL MEASUREMENTS ID INTEGRATING NEPHELOMETERS AB A new nephelometer suitable for aircraft measurements of aerosol scattering extinction coefficient (sigma-sp) has been constructed and operated under field conditions. This instrument is vacuum tight for operation in a pressurized aircraft cabin and is capable of measuring background tropospheric sigma-sp at an averaging time of 1 min. For example, in a typical atmospheric profile the instrument can measure values of about 10(-4) m-1 with a time resolution of 2 s in a polluted region, and about 10(-7) m-1 with a time resolution of 1 min in a clean region. This sensitivity is made possible by: (1) subtracting in real time the air Rayleigh scattering from the total scattering signal by continuously measuring pressure and temperature in the sampling volume of the instrument; (2) correcting for the dark count and sensitivity of the photomultipliers using a rotating shutter; and (3) using a beam splitter arrangement to allow simultaneous detection by three photomultipliers. A laboratory measurement of instrument noise suggests a 550-nm noise level of about 5 x 10(-8) m-1 at an averaging time of 1 min. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP BODHAINE, BA (reprint author), NOAA,R-E-CG1,CLIMATE MONITORING & DIAGNOST LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 22 TC 31 Z9 33 U1 3 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PY 1991 VL 25 IS 10 BP 2267 EP 2276 DI 10.1016/0960-1686(91)90102-D PG 10 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA GB566 UT WOS:A1991GB56600019 ER PT J AU FRIED, A HENRY, B PARRISH, DD CARPENTER, JR BUHR, MP AF FRIED, A HENRY, B PARRISH, DD CARPENTER, JR BUHR, MP TI INTERCOMPARISON OF TUNABLE DIODE-LASER AND GAS FILTER CORRELATION-MEASUREMENTS OF AMBIENT CARBON-MONOXIDE SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE TROPOSPHERIC CARBON MONOXIDE MEASUREMENTS; CARBON MONOXIDE INTERCOMPARISON; TUNABLE DIODE LASER CO MEASUREMENTS; GAS FILTER CORRELATION CO MEASUREMENTS ID EARTHS ATMOSPHERE; INCREASE; REGION; OZONE; BANDS AB An intercomparison that involved a standards intercomparison, interferant spiking tests and simultaneous ambient measurements was carried out between two CO measurement systems: a tunable diode laser absorption spectrometer (TDLAS) and a gas filter correlation, non-dispersive infrared absorption instrument (GFC). Both the TDLAS and the GFC techniques responded to CO. No major interferences were found for the TDLAS system; tested species included H2O, O3 and OCS. The GFC instrument exhibited no interference from H2O or O3, but only a relatively high upper limit could be placed on the O3 interference. For CO measurements in ambient air at levels from 100 to 1500 ppbv, the results from the two instruments agreed within their combined uncertainties. On average the GFC technique was 6% higher than the TDLAS system, and there was no systematic, constant offset. The precision of the GFC instrument was about 10%, and the precision of the TDLAS system was better than 4%. C1 NOAA,AERON LAB,BOULDER,CO 80303. UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP FRIED, A (reprint author), NATL CTR ATMOSPHER RES,POB 3000,BOULDER,CO 80307, USA. RI Parrish, David/E-8957-2010 OI Parrish, David/0000-0001-6312-2724 NR 20 TC 23 Z9 23 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PY 1991 VL 25 IS 10 BP 2277 EP 2284 DI 10.1016/0960-1686(91)90103-E PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA GB566 UT WOS:A1991GB56600020 ER PT J AU HICKS, BB HOSKER, RP MEYERS, TP WOMACK, JD AF HICKS, BB HOSKER, RP MEYERS, TP WOMACK, JD TI DRY DEPOSITION INFERENTIAL MEASUREMENT TECHNIQUES .1. DESIGN AND TESTS OF A PROTOTYPE METEOROLOGICAL AND CHEMICAL-SYSTEM FOR DETERMINING DRY DEPOSITION SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE FILTERPACKS; DRY DEPOSITION; HNO3 MEASUREMENTS; SO2 MEASUREMENTS ID ACID; SO2 AB A simple filterpack system and a supporting meterological and surface-condition monitoring system have been deployed in a trial network to test methods by which dry deposition rates can be estimated on a routine basis, using average air concentration data and site-specific deposition velocities. The filterpack used in this dry deposition inferential measurement (DDIM) sampler differs from standard filterpacks by the use of a heated horizontal settling tube at the inlet. This modification is intended to protect the SO2 sampling system from adverse effects associated with filter liquefaction at high humidities, while at the same time providing a simple means for eliminating large particles from the sampled air. Tests indicate that the sampler works well for SO2 and for particulate species, and that HNO3 concentrations are underestimated by about 25%. The DDIM approach differs from previous network measurement programs in that the data sets are designed to permit extension from observations at a subset of research sites to less intensive routine measurement sites. Hence a major goal is the definition of a suitable set of supporting data from which dry deposition rates can be inferred using air concentration data. Local vegetation characteristics are noted. At present, the additional variables that are monitored are solar radiation, wind speed, wind direction standard deviation, temperature, humidity, surface wetness, and precipitation. Observers report changes in the surrounding surface, such as the presence of snow or unusual drought. RP HICKS, BB (reprint author), NOAA,ERL AIR RESOURCES LAB,DIV ATMOSPHER TURBULENCE & DIFFUS,POB 2456,OAK RIDGE,TN 37831, USA. RI Meyers, Tilden/C-6633-2016 NR 16 TC 81 Z9 82 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PY 1991 VL 25 IS 10 BP 2345 EP 2359 DI 10.1016/0960-1686(91)90109-K PG 15 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA GB566 UT WOS:A1991GB56600026 ER PT J AU MEYERS, TP HICKS, BB HOSKER, RP WOMACK, JD SATTERFIELD, LC AF MEYERS, TP HICKS, BB HOSKER, RP WOMACK, JD SATTERFIELD, LC TI DRY DEPOSITION INFERENTIAL MEASUREMENT TECHNIQUES .2. SEASONAL AND ANNUAL DEPOSITION RATES OF SULFUR AND NITRATE SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE DRY DEPOSITION; TOTAL DEPOSITION; NETWORK MEASUREMENTS; SEASONAL CONCENTRATIONS ID NITROGEN DEPOSITION; DECIDUOUS FOREST; NITRIC-ACID; VEGETATION; FLUXES; NO2; SO2; TERRESTRIAL; ECOSYSTEMS; VELOCITIES AB Since the autumn of 1984, a dry deposition research network has been operated to develop and refine methods to make defensible estimates of dry deposition rates of SO2, sulfate and nitrate (particulate and gaseous) on a routine basis. Ten of the sites are located in the eastern part of the U.S. while two are located in the western half. Annual dry deposition rates of sulfur (SO2 + SO4(2-)) are estimated to range from 2.5 kg ha-1 at Whiteface Mountain, NY to 14 kg ha-1 at Argonne, IL. The majority of deposited sulfur was delivered in the form of SO2. Deposition rates were highest during the summer season even though SO2 concentrations peaked during the winter months because the estimated deposition velocities (V(d)) were much greater in the summer. Nearly all of the dry deposited nitrogen (HNO3 + NO3-) was in the form of HNO3. An annual cycle was not evident in the time series of nitrogen deposition rates. For both sulfur and nitrogen, dry deposition was estimated to provide between 30% and 50% of the total input from the atmosphere (wet + dry) for all sites in the eastern U.S. RP MEYERS, TP (reprint author), NOAA,ERL AIR RESOURCES LAB,DIV ATMOSPHER TURBULENCE & DIFFUS,POB 2456,OAK RIDGE,TN 37831, USA. RI Meyers, Tilden/C-6633-2016 NR 29 TC 87 Z9 88 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PY 1991 VL 25 IS 10 BP 2361 EP 2370 DI 10.1016/0960-1686(91)90110-S PG 10 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA GB566 UT WOS:A1991GB56600027 ER PT J AU PENNER, JE MULHOLLAND, GW AF PENNER, JE MULHOLLAND, GW TI GLOBAL CLIMATIC EFFECTS OF AEROSOLS - THE AAAR SYMPOSIUM - AN OVERVIEW SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Review C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP PENNER, JE (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,PB 808,LIVERMORE,CA 94550, USA. RI Penner, Joyce/J-1719-2012 NR 0 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PY 1991 VL 25 IS 11 BP 2433 EP 2434 DI 10.1016/0960-1686(91)90158-4 PG 2 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA GD148 UT WOS:A1991GD14800001 ER PT J AU BRYNER, NP MULHOLLAND, GW AF BRYNER, NP MULHOLLAND, GW TI SMOKE EMISSION AND BURNING RATES FOR URBAN STRUCTURES SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE SMOKE EMISSIONS; BURNING RATES; URBAN FIRES; NUCLEAR WINTER; SMOKE GENERATION; CRIB BURNING; SCALE EFFECTS; WOOD; ABS PLASTICS; GYPSUM ID NUCLEAR WINTER; OXYGEN-CONSUMPTION; HEAT RELEASE; FIRES AB Cribs, ordered arrays of sticks, were burned to mimic post-nuclear building fires. As the packing density of the cribs was increased to simulate blast damage, the smoke yield increased and the smoke changed from strongly light absorbing to whitish in color. A ventilation parameter proportional to the ratio of the crib vent area to the total fuel surface area correlated the burning rate and smoke yield data for both large (3.81 cm stick thickness) and small (0.64 cm stick thickness) scale cribs. The globally averaged smoke optical depth inferred from the burning of the wood cribs is in the low range of Penner's (1986, Nature 324, 222-226) estimate. The smoke yield for freely burning cribs containing wood, gypsum, and plastic can be accounted for based on the high sooting yield of the plastic by itself. RP BRYNER, NP (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 20 TC 1 Z9 1 U1 2 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PY 1991 VL 25 IS 11 BP 2553 EP 2562 DI 10.1016/0960-1686(91)90172-4 PG 10 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA GD148 UT WOS:A1991GD14800015 ER PT J AU DRAXLER, RR DIETZ, R LAGOMARSINO, RJ START, G AF DRAXLER, RR DIETZ, R LAGOMARSINO, RJ START, G TI ACROSS NORTH-AMERICA TRACER EXPERIMENT (ANATEX) - SAMPLING AND ANALYSIS SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE ANATEX; LONG-RANGE TRANSPORT; DISPERSION; TRACER EXPERIMENT; PERFLUOROCARBON ID CAPTEX DATA; TRANSPORT; MODEL AB Between 5 January 1987 and 29 March 1987, there were 33 releases of different tracers from each of two sites: Glasgow, MT and St. Cloud, MN. The perfluorocarbon tracers were routinely released in a 3-h period every 2.5 days, alternating between daytime and night-time tracer releases. Ground-level air samples of 24-h duration were taken at 77 sites mostly located near rawinsonde stations east of 105-degrees-W and between 26-degrees-N and 55-degrees-N. Weekly air samples were taken at 12 remote sites between San Diego, CA and Pt. Barrow, AK and between Norway and the Canary Islands. Short-term 6-h samples were collected at ground level and 200 m AGL along an arc of five towers between Tulsa, OK and Green Bay, WI. Aircraft sampling within several hundred kilometers of both tracer release sites was used to establish the initial tracer path. Experimental design required improved sampler performance, new tracers with lower atmospheric backgrounds, and improvements in analytic precision. The advances to the perfluorocarbon tracer system are discussed in detail. Results from the tracer sampling showed that the average and peak concentrations measured over the daily ground-level sampling network were consistent with what would be calculated using mass conservative approaches. However, ground-level samples from individual tracer patterns showed considerable complexity due to vertical stability or the interaction of the tracer plumes with low pressure and frontal systems. These systems could pass right through the tracer plume without appreciable effect. Aircraft tracer measurements are used to confirm the initial tracer trajectory when the narrow plume may miss the coarser spaced ground-level sampling network. Tower tracer measurements showed a more complex temporal structure than evident from the longer duration ground-level sampling sites. Few above background plume measurements were evident in the more distant remote sampling network due to larger than expected uncertainties in the ambient background concentrations. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. ENVIRONM MEASUREMENTS LAB,NEW YORK,NY 10014. RP DRAXLER, RR (reprint author), NOAA,1325 E W HIGHWAY,SILVER SPRING,MD 20910, USA. NR 29 TC 42 Z9 44 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0004-6981 J9 ATMOS ENVIRON A-GEN PY 1991 VL 25 IS 12 BP 2815 EP 2836 DI 10.1016/0960-1686(91)90208-O PG 22 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA GN034 UT WOS:A1991GN03400014 ER PT J AU SNYDER, WH LAWSON, RE AF SNYDER, WH LAWSON, RE TI FLUID MODELING SIMULATION OF STACK-TIP DOWNWASH FOR NEUTRALLY BUOYANT PLUMES SO ATMOSPHERIC ENVIRONMENT PART A-GENERAL TOPICS LA English DT Article DE STACK-TIP DOWNWASH; ATMOSPHERIC DIFFUSION; WIND-TUNNEL MODELING; AIR POLLUTION AB Downwash of neutrally buoyant effluent on the immediate lee side of a circular stack was modeled using a wind-tunnel simulation. Both subcritical and supercritical turbulent flows were simulated, where the criticality refers to Reynolds numbers below and above the critical Reynolds number, Re(c) (congruent-to 2 x 10(5)), where the boundary layer on the cylinder becomes turbulent and the drag coefficient drops sharply. Subcritical Reynolds numbers are typically attained by small-diameter stacks in relatively light winds; supercritical ones are attained by large-diameter stacks in strong winds. The downwash characteristics differ markedly in the two regimes. In the subcritical regime, downwash begins when the ratio of effluent speed to wind speed (W/U) is about 1.5; in the supercritical regime, downwash begins at W/U congruent-to 1.1. The downwash in the immediate lee of the stack at W/U = 0.3 extends to 7 diameters down from the stack top in the subcritical regime and to 4 diameters down in the supercritical regime. Graphs and simple formulas are presented describing the plume trajectories and plume widths for 0.4 less-than-or-equal-to W/U less-than-or-equal-to 2.0 and for downwind distances from the source to 30 stack diameters. Practical recommendations are made for modeling the downwash of neutrally buoyant plumes. C1 NOAA, AIR RESOURCES LAB, DIV ATMOSPHER SCI MODELING, RES TRIANGLE PK, NC 27711 USA. RP SNYDER, WH (reprint author), US EPA, ATMOSPHER RES & EXPOSURE ASSESSMENT LAB, WASHINGTON, DC 20460 USA. NR 19 TC 13 Z9 13 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0004-6981 J9 ATMOS ENVIRON A-GEN PY 1991 VL 25 IS 12 BP 2837 EP 2850 DI 10.1016/0960-1686(91)90209-P PG 14 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA GN034 UT WOS:A1991GN03400015 ER PT J AU MISAKIAN, M AF MISAKIAN, M TI INVITRO EXPOSURE PARAMETERS WITH LINEARLY AND CIRCULARLY POLARIZED ELF MAGNETIC-FIELDS SO BIOELECTROMAGNETICS LA English DT Note DE DOSIMETRY; CURRENT DENSITY; ELECTRIC FIELD; EXPOSURE SYSTEM AB A comparison is made of induced current densities, electric fields, and rates of energy deposition during in vitro studies with linearly and circularly polarized, extremely low frequency magnetic fields for a cylindrical volume of culture medium. RP MISAKIAN, M (reprint author), NATL INST STAND & TECHNOL,DIV ELECT,BLDG 220,ROOM B344,GAITHERSBURG,MD 20899, USA. NR 1 TC 5 Z9 5 U1 0 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0197-8462 J9 BIOELECTROMAGNETICS JI Bioelectromagnetics PY 1991 VL 12 IS 6 BP 377 EP 381 DI 10.1002/bem.2250120606 PG 5 WC Biology; Biophysics SC Life Sciences & Biomedicine - Other Topics; Biophysics GA GN924 UT WOS:A1991GN92400005 PM 1750830 ER PT B AU IYENGAR, GV AF IYENGAR, GV BE SUBRAMANIAN, KS IYENGAR, GV OKAMOTO, K TI THE NEED FOR MULTIDISCIPLINARY APPROACHES IN BIOLOGICAL TRACE-ELEMENT RESEARCH SO BIOLOGICAL TRACE ELEMENT RESEARCH /: MULTIDISCIPLINARY PERSPECTIVES SE ACS SYMPOSIUM SERIES LA English DT Review CT SYMP ON BIOLOGICAL TRACE ELEMENT RESEARCH : MULTIDISCIPLINARY PERSPECTIVES CY DEC 17-22, 1989 CL HONOLULU, HI SP INT CHEM CONGRESS PACIFIC BASIN SOC ID SAMPLE PREPARATION; REFERENCE VALUES; HEALTH RP IYENGAR, GV (reprint author), NATL INST STAND & TECHNOL,REACTOR BLDG 235,B125,GAITHERSBURG,MD 20899, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA WASHINGTON BN 0-8412-1888-9 J9 ACS SYM SER PY 1991 VL 445 BP 1 EP 13 PG 13 WC Biology; Medicine, Research & Experimental; Multidisciplinary Sciences SC Life Sciences & Biomedicine - Other Topics; Research & Experimental Medicine; Science & Technology - Other Topics GA BS49J UT WOS:A1991BS49J00001 ER PT B AU CURRIE, LA AF CURRIE, LA BE SUBRAMANIAN, KS IYENGAR, GV OKAMOTO, K TI THE IMPORTANCE OF CHEMOMETRICS IN BIO-MEDICAL MEASUREMENTS SO BIOLOGICAL TRACE ELEMENT RESEARCH /: MULTIDISCIPLINARY PERSPECTIVES SE ACS SYMPOSIUM SERIES LA English DT Review CT SYMP ON BIOLOGICAL TRACE ELEMENT RESEARCH : MULTIDISCIPLINARY PERSPECTIVES CY DEC 17-22, 1989 CL HONOLULU, HI SP INT CHEM CONGRESS PACIFIC BASIN SOC RP CURRIE, LA (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA WASHINGTON BN 0-8412-1888-9 J9 ACS SYM SER PY 1991 VL 445 BP 74 EP 100 PG 27 WC Biology; Medicine, Research & Experimental; Multidisciplinary Sciences SC Life Sciences & Biomedicine - Other Topics; Research & Experimental Medicine; Science & Technology - Other Topics GA BS49J UT WOS:A1991BS49J00006 ER PT B AU DEVOE, JR AF DEVOE, JR BE SUBRAMANIAN, KS IYENGAR, GV OKAMOTO, K TI ESTABLISHING QUALITY MEASUREMENTS FOR INORGANIC ANALYSIS OF BIOMATERIALS SO BIOLOGICAL TRACE ELEMENT RESEARCH /: MULTIDISCIPLINARY PERSPECTIVES SE ACS SYMPOSIUM SERIES LA English DT Review CT SYMP ON BIOLOGICAL TRACE ELEMENT RESEARCH : MULTIDISCIPLINARY PERSPECTIVES CY DEC 17-22, 1989 CL HONOLULU, HI SP INT CHEM CONGRESS PACIFIC BASIN SOC RP DEVOE, JR (reprint author), NATL INST STANDARDS & TECHNOL,CTR ANALYT CHEM,DIV INORGAN ANALYT RES,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA WASHINGTON BN 0-8412-1888-9 J9 ACS SYM SER PY 1991 VL 445 BP 101 EP 106 PG 6 WC Biology; Medicine, Research & Experimental; Multidisciplinary Sciences SC Life Sciences & Biomedicine - Other Topics; Research & Experimental Medicine; Science & Technology - Other Topics GA BS49J UT WOS:A1991BS49J00007 ER PT B AU STONE, SF ZEISLER, R GORDON, GE VISCIDI, RP CERNY, EH AF STONE, SF ZEISLER, R GORDON, GE VISCIDI, RP CERNY, EH BE SUBRAMANIAN, KS IYENGAR, GV OKAMOTO, K TI TRACE-ELEMENTS ASSOCIATED WITH PROTEINS - NEUTRON-ACTIVATION ANALYSIS COMBINED WITH BIOLOGICAL ISOLATION TECHNIQUES SO BIOLOGICAL TRACE ELEMENT RESEARCH /: MULTIDISCIPLINARY PERSPECTIVES SE ACS SYMPOSIUM SERIES LA English DT Review CT SYMP ON BIOLOGICAL TRACE ELEMENT RESEARCH : MULTIDISCIPLINARY PERSPECTIVES CY DEC 17-22, 1989 CL HONOLULU, HI SP INT CHEM CONGRESS PACIFIC BASIN SOC RP STONE, SF (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA WASHINGTON BN 0-8412-1888-9 J9 ACS SYM SER PY 1991 VL 445 BP 265 EP 277 PG 13 WC Biology; Medicine, Research & Experimental; Multidisciplinary Sciences SC Life Sciences & Biomedicine - Other Topics; Research & Experimental Medicine; Science & Technology - Other Topics GA BS49J UT WOS:A1991BS49J00021 ER PT J AU FRISCH, AS AF FRISCH, AS TI ON THE MEASUREMENT OF 2ND MOMENTS OF TURBULENT WIND VELOCITY WITH A SINGLE DOPPLER RADAR OVER NONHOMOGENEOUS TERRAIN SO BOUNDARY-LAYER METEOROLOGY LA English DT Article AB The measurement of turbulent wind quantities with a single Doppler radar requires a horizontal homogeneity assumption. When the terrain is not horizontally homogeneous, then the measurement of the various moments is contaminated by the gradients of these moments. However, by scanning the radar at three different elevation angles, the contamination from these gradients can be removed from the second-moment quantities of interest. RP FRISCH, AS (reprint author), NOAA,ENVIRONM RES LABS,BOULDER,CO 80303, USA. NR 5 TC 3 Z9 3 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD JAN PY 1991 VL 54 IS 1-2 BP 29 EP 39 DI 10.1007/BF00119410 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA EW110 UT WOS:A1991EW11000002 ER PT J AU NAPPO, CJ AF NAPPO, CJ TI SPORADIC BREAKDOWNS OF STABILITY IN THE PBL OVER SIMPLE AND COMPLEX TERRAIN SO BOUNDARY-LAYER METEOROLOGY LA English DT Article ID INTERNAL GRAVITY-WAVES; BOUNDARY-LAYER; TURBULENCE; TOWER AB Breakdowns of stability in the PBL are examined using one-minute average horizontal wind speeds and temperatures observed over many nights at stations located in simple and complex terrain. The analysis is based on the temporal behavior of the wind speed-temperature covariance, which is obtained by digital bandpass filtering. It is shown that breakdowns are a common feature of the stable PBL over both simple and complex environments. Vertical fluxes of heat during breakdowns are estimated to be a significant fraction of the nighttime average heat flux. It is hypothesized that a major portion of the nighttime vertical transfer of heat, momentum, and atmospheric pollutants occurs during periods of stability breakdowns. RP NAPPO, CJ (reprint author), NOAA,AIR RESOURCES LAB,DIV ATMOSPHER TURBULENCE & DIFFUS,POB 23456,OAK RIDGE,TN 37831, USA. NR 24 TC 97 Z9 98 U1 0 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD JAN PY 1991 VL 54 IS 1-2 BP 69 EP 87 DI 10.1007/BF00119413 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA EW110 UT WOS:A1991EW11000005 ER PT J AU COLLETTE, BB PARIN, NV AF COLLETTE, BB PARIN, NV TI SHALLOW-WATER FISHES OF WALTERS SHOALS, MADAGASCAR RIDGE SO BULLETIN OF MARINE SCIENCE LA English DT Article ID NEW-ZEALAND; REEF-FISH; REVISION AB Walters Shoals is an isolated seamount reaching to within 18 m of the surface, and is located about 400 nautical miles south of Madagascar and 600 nm east of South Africa. It is part of a chain of seven islands and seamounts extending along the West Wind Drift from Gough and Tristan da Cunha in the South Atlantic to Amsterdam and St. Paul in the sourthern Indian Ocean. Fishes were collected during VITYAZ cruise 17 in December 1988. The shallow-water fish fauna comprises about 20 species and is composed of three elements: endemics (7-8 species), wide-spread temperate or subtropical species (5-6), and tropical Indo-West Pacific reef species (6). Three species, a carangid, Trachurus longimanus, a cheilodactylid, Acantholatris monodactylus, and a labrid, Nelabrichthys ornatus, are endemic to the West Wind Drift islands. A serranid, Lepidoperca coatsii, is known from four of the island groups and may also occur at Walters Shoals. Another serranid, Serranus novemcinctus, occurs only at the four Indian Ocean islands and seamounts. The common Gymnothorax is an undescribed species, probably endemic. A specimen of scorpaenid has been described as Scorpaenodes immaculatus, also probably endemic. A second species of Gymnothorax and the species of Plagiogeneion may also be endemic species. Thus, 30-40% of the shallow water fish fauna of Walters Shoals is endemic to some part of this chain of islands and seamounts. The species of Carcharhinus, Cheilopogon, Polyprion, Seriola, and Scomber are wide-spread in temperate or subtropical waters. Plectranthias longimanus, Apogon semiornatus, Chromis weberi, C. axillaris, Pterois cf. miles, and Kentrocapros rosapinto are tropical Indo-West Pacific reef fishes. The fish fauna of Walters Shoals links Briggs's Tristan-Gough Province of his southern South American Cold Temperate Region with the Amsterdam-St. Paul Province of his Southern African Warm Temperate Region into a single zoogeographic province, which is here called the West Wind Drift Islands Province. C1 PP SHIRSHOV OCEANOL INST,MOSCOW 117218,USSR. RP COLLETTE, BB (reprint author), NATL MUSEUM NAT HIST,NATL MARINE FISHERIES SERV,SYSTEMAT LAB,WASHINGTON,DC 20560, USA. NR 57 TC 25 Z9 26 U1 1 U2 3 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD JAN PY 1991 VL 48 IS 1 BP 1 EP 22 PG 22 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA FC807 UT WOS:A1991FC80700001 ER PT J AU BAER, VE AF BAER, VE TI THE TRANSITION FROM THE PRESENT RADAR DISSEMINATION SYSTEM TO THE NEXRAD INFORMATION DISSEMINATION SERVICE (NIDS) SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB The National Weather Service (NWS) will begin replacing its current system of weather radars with Next Generation Weather Radars (NEXRAD) in late 1990. Presented is an overview of previous and current systems, and the replacement NEXRAD Information Dissemination Service (NIDS), for the dissemination of radar products to government and private users. The NIDS will be implemented and operated for the NWS by private sector data providers under a memorandum of agreement. The requirements of the NIDS, the suite of products to be provided, and its implementation milestones are described. RP BAER, VE (reprint author), NOAA,NATL WEATHER SERV,OFF SYST OPERAT,DIV SYST INTEGRAT,SILVER SPRING,MD 20910, USA. NR 7 TC 27 Z9 27 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD JAN PY 1991 VL 72 IS 1 BP 29 EP 33 DI 10.1175/1520-0477(1991)072<0029:TTFTPR>2.0.CO;2 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA EY148 UT WOS:A1991EY14800003 ER PT J AU ALNESIR, R KEENAN, V LANGER, P AF ALNESIR, R KEENAN, V LANGER, P TI FIELD DEPENDENCE-INDEPENDENCE IN THE DEVELOPMENT OF REFERENTIAL COMMUNICATION SO BULLETIN OF THE PSYCHONOMIC SOCIETY LA English DT Article ID CHILDRENS C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,DEPT PSYCHOL,MUENZINGER PSYCHOL BLDG,BOULDER,CO 80309. MUTAH UNIV,MUTAH,JORDAN. NR 3 TC 2 Z9 2 U1 1 U2 1 PU PSYCHONOMIC SOC INC PI AUSTIN PA 1710 FORTVIEW RD, AUSTIN, TX 78704 SN 0090-5054 J9 B PSYCHONOMIC SOC PD JAN PY 1991 VL 29 IS 1 BP 17 EP 18 PG 2 WC Psychology, Mathematical SC Psychology GA EV519 UT WOS:A1991EV51900006 ER PT J AU ORSI, JA GISH, RK WING, BL AF ORSI, JA GISH, RK WING, BL TI NORTHERN RANGE EXTENSIONS OF 4 NEARSHORE MARINE FISHES IN ALASKA SO CANADIAN FIELD-NATURALIST LA English DT Article DE PAINTED GREENLING; OXYLEBIUS-PICTUS; BAY PIPEFISH; SYNGNATHUS-LEPTOHYNCHUS; MANACLED SCULPIN; SYNCHIRUS-GILLI; SPECKLED SANDDAB; CITHARICHTHYS-STIGMAEUS; PRINCE WILLIAM SOUND; ALASKA AB Northern range extensions of Oxylebius pictus (Hexagrammidae), Syngnathus leptorhynchus (Syngnathidae), Synchirus gilli (Cottidae), and Citharichthys stigmaeus (Bothidae) are reported. All four species were collected north of 60-degrees-N in Prince William Sound in the Gulf of Alaska from April through June 1989. This is the first published account of a verified specimen of O. pictus in Alaska. RP ORSI, JA (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,AUKE BAY LAB,POB 210155,AUKE BAY,AK 99821, USA. NR 0 TC 3 Z9 4 U1 0 U2 2 PU OTTAWA FIELD-NATURALISTS CLUB PI OTTAWA PA BOX 3264 POSTAL STATION C, OTTAWA ON K1Y 4J5, CANADA SN 0008-3550 J9 CAN FIELD NAT JI Can. Field-Nat. PD JAN-MAR PY 1991 VL 105 IS 1 BP 82 EP 86 PG 5 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA FR496 UT WOS:A1991FR49600014 ER PT J AU HINCKLEY, S BAILEY, KM PICQUELLE, SJ SCHUMACHER, JD STABENO, PJ AF HINCKLEY, S BAILEY, KM PICQUELLE, SJ SCHUMACHER, JD STABENO, PJ TI TRANSPORT, DISTRIBUTION, AND ABUNDANCE OF LARVAL AND JUVENILE WALLEYE POLLOCK (THERAGRA-CHALCOGRAMMA) IN THE WESTERN GULF OF ALASKA SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID SHELIKOF STRAIT; COASTAL CURRENT; SURVIVAL AB The spawning distribution of walleye pollock (Theragra chalcogramma) and subsequent southwesterly drift of eggs, lavae, and juveniles were investigated in Shelikof Strait, March-September 1987. In mid-March, a hydroacoustics survey found that spawning adults were concentrated in the deeper parts of Shelikof Strait, as were eggs collected in this area during an ichthyoplankton survey about 1 mo later. In May, a concentration of young larvae was found 100-150 km to the southwest of the spawning area. In late June and early July, the center of distribution of late larval and early juvenile walleye pollock was further to the southwest, between the Shumagin and Semidi Islands. By August and September, juveniles were mostly distributed downstream of the Shumagin Islands. The rate of drift of eggs and larvae through June was estimated at 4-6 cm/s. The trajectories of satellite-tracked buoys deployed in the region of greatest egg abundance revealed similar patterns to those of the early life stages of walleye pollock. These observations demonstrate that transport is an important factor determining the distribution of pollock larvae in downstream coastal nursery areas. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. RP HINCKLEY, S (reprint author), NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 30 TC 48 Z9 50 U1 3 U2 6 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD JAN PY 1991 VL 48 IS 1 BP 91 EP 98 DI 10.1139/f91-013 PG 8 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA ET781 UT WOS:A1991ET78100013 ER PT J AU WAPLES, RS AF WAPLES, RS TI GENETIC INTERACTIONS BETWEEN HATCHERY AND WILD SALMONIDS - LESSONS FROM THE PACIFIC-NORTHWEST SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article; Proceedings Paper CT SYMP ON THE ECOLOGICAL AND GENETIC IMPLICATIONS OF FISH INTRODUCTIONS CY MAY 17-19, 1990 CL UNIV WINDSOR, GREAT LAKES INST, WINDSOR, CANADA HO UNIV WINDSOR, GREAT LAKES INST ID EFFECTIVE POPULATION-SIZE; SOUTHERN BRITISH-COLUMBIA; ONCORHYNCHUS-KISUTCH; CONSERVATION GENETICS; STEELHEAD TROUT; INTERANNUAL VARIABILITY; STOCK IDENTIFICATION; PINK SALMON; COHO; OCEAN AB The potential for genetic interactions between hatchery and wild populations of salmonids in northwestern North America has increased considerably in recent decades. Efforts to mitigate severe losses to many wild stocks caused by overfishing, destruction of habitat, and blockage of migratory routes have focussed on boosting artificial production in public hatcheries. Opportunities for genetic interactions between hatchery and wild fish will increase if efforts to supplement wild production with hatchery-reared fish continue. Concerns center on three issues: (1) direct genetic effects (caused by hybridization and introgression); (2) indirect genetic effects (principally due to altered selection regimes or reductions in population size caused by competition, predation, disease, or other factors); and (3) genetic changes to hatchery stocks (through selection, drift, or stock transfers), which magnify the consequences of hybridization with wild fish. Strategies for minimizing these genetic risks and monitoring the consequences of various management options are discussed, and some important areas for future research are identified. RP WAPLES, RS (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES CTR,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. RI Waples, Robin/K-1126-2016 NR 85 TC 246 Z9 252 U1 2 U2 56 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PY 1991 VL 48 SU 1 BP 124 EP 133 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA HB543 UT WOS:A1991HB54300014 ER PT B AU TODD, P PRETLOW, TG AF TODD, P PRETLOW, TG BE KOMPALA, DS TODD, P TI SEPARATION OF LIVING CELLS SO CELL SEPARATION SCIENCE AND TECHNOLOGY SE ACS SYMPOSIUM SERIES LA English DT Review CT SYMP AT THE 199TH NATIONAL MEETING OF THE AMERICAN CHEMICAL SOC : CELL SEPARATION SCIENCE AND TECHNOLOGY CY APR 22-27, 1990 CL BOSTON, MA SP AMER CHEM SOC, DIV IND & ENGN CHEM, AMER CHEM SOC, DIV BIOCHEM TECHNOL ID ELECTROPHORETIC SEPARATION; 2-PHASE SYSTEMS; FLOW-CYTOMETRY; PROTEINS; PARTITION; TISSUES RP TODD, P (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,325 BROADWAY 831.02,BOULDER,CO 80303, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA WASHINGTON BN 0-8412-2090-5 J9 ACS SYM SER PY 1991 VL 464 BP 1 EP 24 PG 24 WC Chemistry, Multidisciplinary; Engineering, Biomedical SC Chemistry; Engineering GA BT66M UT WOS:A1991BT66M00001 ER PT B AU TODD, P AF TODD, P BE KOMPALA, DS TODD, P TI COMPARISON OF METHODS OF PREPARATIVE CELL ELECTROPHORESIS SO CELL SEPARATION SCIENCE AND TECHNOLOGY SE ACS SYMPOSIUM SERIES LA English DT Review CT SYMP AT THE 199TH NATIONAL MEETING OF THE AMERICAN CHEMICAL SOC : CELL SEPARATION SCIENCE AND TECHNOLOGY CY APR 22-27, 1990 CL BOSTON, MA SP AMER CHEM SOC, DIV IND & ENGN CHEM, AMER CHEM SOC, DIV BIOCHEM TECHNOL ID CONTINUOUS-FLOW ELECTROPHORESIS; DENSITY GRADIENT ELECTROPHORESIS; SEPARATION; SURFACE; CHARGE; SEDIMENTATION; POPULATIONS; DIFFUSION; PARTICLES; TISSUES RP TODD, P (reprint author), NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,325 BROADWAY 83102,BOULDER,CO 80303, USA. NR 0 TC 1 Z9 1 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA WASHINGTON BN 0-8412-2090-5 J9 ACS SYM SER PY 1991 VL 464 BP 216 EP 255 PG 40 WC Chemistry, Multidisciplinary; Engineering, Biomedical SC Chemistry; Engineering GA BT66M UT WOS:A1991BT66M00015 ER PT J AU TOMAZIC, BB SIEW, C BROWN, WE AF TOMAZIC, BB SIEW, C BROWN, WE TI A COMPARATIVE-STUDY OF BOVINE PERICARDIUM MINERALIZATION - A BASIC AND PRACTICAL APPROACH SO CELLS AND MATERIALS LA English DT Article DE BIOAPATITE; BOVINE PERICARDIUM; CARDIOVASCULAR BIOMINERALIZATION; HYDROXYAPATITE; OCTACALCIUM PHOSPHATE; SOLUBILITY ID BIOPROSTHETIC HEART-VALVES; OCTACALCIUM PHOSPHATE; CALCIFICATION; SOLUBILITY; COLLAGEN; DEPOSITS AB The biomineralization of bovine pericardium (BP) heart valve bioprostheses was investigated by simulation of the process under in vitro and in vivo conditions. The nature and composition of calcific deposits that formed in human heart valve bioprostheses were compared with the mineral formed on BP discs immersed in a calcifying medium or subcutaneously implanted into Sprague-Dawley rats. The early stage of experimental biomineralization in vitro took place on the surface only, while in vivo deposition appeared to be intrinsic, as documented by histological cross sections. The chemical composition of the initial mineral phase formed under in vitro conditions had a mean molar Ca/P ratio = 1.255, standard deviation (S.D.) = 0.057, (n = 6). The composition of mineral formed under in vivo conditions had a low initial Ca/P ratio. From 4 days to three weeks the average in vivo ratio was 1.239, S.D. = 0.203 (n = 38). This ratio increased to 1.707, S.D. = 0.038 (n = 6) following seven weeks of implantation. The latter ratio is similar to that of biomineral formed in human bioprostheses: Ca/P = 1.645, S.D. = 0.021 (n = 6). The deproteinated biomineral showed a population of microparticles in the range of 50-200 nm with a microcrystalline apatitic X-ray diffraction pattern. The biomineral contained a significant amount of carbonate, and the solubility was markedly higher than the solubility of hydroxyapatite. Combined information from in vitro, in vivo and bioprosthetic mineralization supports the concept that octacalcium phosphate is a precursor that transforms into bioapatite and is implicated in the calcification of bioprosthetic heart valves. C1 AMER DENT ASSOC FDN, RES INST, CHICAGO, IL 60611 USA. RP TOMAZIC, BB (reprint author), NATL INST STAND & TECHNOL, AMER DENT ASSOC FDN, PAFFENBARGER RES CTR, BLDG 224, ROOM A153, GAITHERSBURG, MD 20899 USA. NR 40 TC 6 Z9 6 U1 0 U2 0 PU SCANNING MICROSCOPY INT PI CHICAGO PA PO BOX 66507, AMF O'HARE, CHICAGO, IL 60666 USA SN 1051-6794 J9 CELL MATER JI Cells Mat. PY 1991 VL 1 IS 3 BP 231 EP 241 PG 11 WC Cell Biology; Medicine, Research & Experimental; Materials Science, Biomaterials SC Cell Biology; Research & Experimental Medicine; Materials Science GA GK713 UT WOS:A1991GK71300005 ER PT J AU WIEDERHORN, SM HOCKEY, BJ AF WIEDERHORN, SM HOCKEY, BJ TI HIGH-TEMPERATURE DEGRADATION OF STRUCTURAL COMPOSITES SO CERAMICS INTERNATIONAL LA English DT Article AB Ceramic matrix composites are being developed to improve the toughness of ceramics in structural applications. Modest success has been experienced in manufacturing ceramic matrix composites for which it is possible to double the room temperature toughness while still retaining the high strength of the untoughened material. As many of these new composites are expected to be used at high temperatures, their mechanical behavior at both high and low temperature must be characterized. In this paper, creep and creep rupture of both particulate and whisker reinforced ceramic matrix composites are discussed. Principal findings of experimental investigations on these materials indicate: (1) resistance to creep deformation is greater in compression than in tension; (2) the creep rupture lifetime follows a Monkman-Grant behavior in which the lifetime can be expressed as a power function of the steady state creep rate; (3) the principal mechanism of failure in creep is interfacial cavitation. Cavities nucleate at interfaces and then grow into full facet cavities. Failure occurs either by the growth or the linkage of these cavities to form critical size cracks in the composite. RP WIEDERHORN, SM (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 5 Z9 5 U1 0 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0272-8842 J9 CERAM INT JI Ceram. Int. PY 1991 VL 17 IS 4 BP 243 EP 252 DI 10.1016/0272-8842(91)90018-U PG 10 WC Materials Science, Ceramics SC Materials Science GA GF832 UT WOS:A1991GF83200004 ER PT J AU HSU, JCL PRESSER, C CLAY, DT AF HSU, JCL PRESSER, C CLAY, DT TI INSITU FUME PARTICLE-SIZE AND NUMBER DENSITY-MEASUREMENTS FROM A SYNTHETIC SMELT SO CHEMICAL ENGINEERING COMMUNICATIONS LA English DT Article DE FUME PARTICLES; MULTI-ANGULAR LIGHT SCATTERING; PARTICLE SIZE; POLARIZATION RATIO; RECOVERY BOILER; SYNTHETIC SMELT ID SPRAY C1 INST PAPER SCI & TECHNOL,ATLANTA,GA 30318. NATL INST STAND & TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899. NR 26 TC 2 Z9 2 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 0098-6445 J9 CHEM ENG COMMUN JI Chem. Eng. Commun. PY 1991 VL 102 BP 189 EP 209 DI 10.1080/00986449108910856 PG 21 WC Engineering, Chemical SC Engineering GA FR162 UT WOS:A1991FR16200011 ER PT J AU NISHIMOTO, M ROUBAL, WT STEIN, JE VARANASI, U AF NISHIMOTO, M ROUBAL, WT STEIN, JE VARANASI, U TI OXIDATIVE DNA DAMAGE IN TISSUES OF ENGLISH SOLE (PAROPHRYS-VETULUS) EXPOSED TO NITROFURANTOIN SO CHEMICO-BIOLOGICAL INTERACTIONS LA English DT Article DE ENGLISH SOLE; NITROFURANTOIN; OXIDATIVE DNA DAMAGE; 8-HYDROXY-2'-DEOXYGUANOSINE ID SUPEROXIDE PRODUCTION; REDUCTIVE METABOLISM; RAT HEPATOCYTES; FREE-RADICALS; LIVER; STRESS; FISH; 8-HYDROXY-2'-DEOXYGUANOSINE; 8-HYDROXYDEOXYGUANOSINE; 8-HYDROXYGUANINE AB Juvenile English sole were exposed intramuscularly to nitrofurantoin (NF) and the levels of 8-hydroxy-2'deoxyguanosine (8-OH-dG) in liver, kidney and blood were determined using reversed-phase HPLC with electrochemical detection. Identification and quantitation of the 8-OH-dG in the samples was accomplished by comparison with standard 8-OH-dG, which was characterized by UV spectroscopy and fast-atom bombardment mass spectrometry. The levels of hepatic 8-OH-dG increased (r2 = 0.59, P = 0.015) with the dose of NF (0.10-10 mg NF/kg fish). In kidney and blood, however, the levels of 8-OH-dG were significantly higher than controls only at the highest dose tested. The level of binding in liver ranged from 0.37 to 0.76 fmol 8-OH-dG/mu-g DNA. The levels of hepatic 8-OH-dG reached a maximum (approx. 1 fmol 8-OH-dG/mu-g DNA) between 1 and 3 days after exposure, followed by a decrease to control levels (approx. 0.25 fmol 8-OH-dG/mu-g DNA) at 5 days post-exposure. These data demonstrate the first direct evidence for the formation of oxidized DNA bases resulting from the metabolism of a nitroaromatic compound by fish. RP NISHIMOTO, M (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES CTR,DIV ENVIRONM CONSERVAT,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. NR 44 TC 29 Z9 32 U1 2 U2 4 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0009-2797 J9 CHEM-BIOL INTERACT JI Chem.-Biol. Interact. PY 1991 VL 80 IS 3 BP 317 EP 326 DI 10.1016/0009-2797(91)90091-K PG 10 WC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Toxicology SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Toxicology GA GU065 UT WOS:A1991GU06500006 PM 1954659 ER PT J AU HARRISON, WTA GIER, TE MORAN, KL NICOL, JM ECKERT, H STUCKY, GD AF HARRISON, WTA GIER, TE MORAN, KL NICOL, JM ECKERT, H STUCKY, GD TI STRUCTURES AND PROPERTIES OF NEW ZEOLITE X-TYPE ZINCOPHOSPHATE AND BERYLLOPHOSPHATE MOLECULAR-SIEVES SO CHEMISTRY OF MATERIALS LA English DT Note ID CRYSTAL-STRUCTURE C1 UNIV CALIF SANTA BARBARA,DEPT CHEM,SANTA BARBARA,CA 93106. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV MARYLAND,COLLEGE PK,MD 20742. RI Eckert, Hellmut/G-3176-2012 NR 12 TC 90 Z9 91 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JAN-FEB PY 1991 VL 3 IS 1 BP 27 EP 29 DI 10.1021/cm00013a012 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA EW486 UT WOS:A1991EW48600013 ER PT J AU MILLER, PJ BLOCK, S PIERMARINI, GJ AF MILLER, PJ BLOCK, S PIERMARINI, GJ TI EFFECTS OF PRESSURE ON THE THERMAL-DECOMPOSITION KINETICS, CHEMICAL-REACTIVITY AND PHASE-BEHAVIOR OF RDX SO COMBUSTION AND FLAME LA English DT Article ID 1,3,5,7-TETRANITRO-1,3,5,7-TETRAAZACYCLOOCTANE; NITROMETHANE; ACTIVATION; EXPLOSIVES; CELL; KBAR AB The effects of pressure on the thermal decomposition kinetics, chemical reactivity, and phase behavior of RDX have been studied by a combination of measurement techniques in conjunction with a high-pressure diamond anvil cell. These techniques include (1) Fourier transform infrared (FTIR) spectroscopy for kinetic measurements and phase identification, (2) energy dispersive x-ray powder diffraction for identification of the observed polymorphic forms and also compression measurements, and (3) optical polarizing microscopy for visual detection and confirmation of phase transformations and determinations of transition pressures. The ruby method of pressure measurement was used in all methods employed. Studies were generally limited to the region where decomposition rates could be measured within reasonable laboratory time, i.e., below 10 GPa and 573 K. The P-T phase diagram for RDX was determined to 573 K and 7.0 GPa, delineating the stability fields of three solid phases, alpha, beta, and gamma, and the liquidus. The alpha and beta phases of RDX were found to thermally decompose, while the gamma phase transformed to either alpha or beta before reaching decomposition temperatures. The decomposition rate of alpha phase was found to increase with increasing pressure, suggesting a bimolecular-type mechanism. An activation energy of 51 kcal/mol and activation volume of -5.6 cm3/mol were calculated for the thermal decomposition reaction of alpha RDX. C1 NATL INST STAND & TECHNOL,INST MAT SCI & ENGN,GAITHERSBURG,MD 20899. RP MILLER, PJ (reprint author), USN,CTR SURFACE WARFARE,WHITE OAK,MD 20910, USA. NR 26 TC 53 Z9 53 U1 3 U2 14 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD JAN PY 1991 VL 83 IS 1-2 BP 174 EP 184 DI 10.1016/0010-2180(91)90211-S PG 11 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA EW535 UT WOS:A1991EW53500013 ER PT J AU GORE, JP EVANS, DD MCCAFFREY, BJ AF GORE, JP EVANS, DD MCCAFFREY, BJ TI TEMPERATURE AND RADIATION OF DIFFUSION FLAMES WITH SUPPRESSION SO COMBUSTION SCIENCE AND TECHNOLOGY LA English DT Article ID REACTION-RATES; WATER; EXTINCTION C1 NATL INST STAND & TECHNOL,CTR FIRE RES,GAITHERSBURG,MD 20899. UNIV MARYLAND,DEPT MECH ENGN,CATONSVILLE,MD 21228. RP GORE, JP (reprint author), UNIV MARYLAND,DEPT MECH ENGN,COLLEGE PK,MD 20742, USA. NR 21 TC 1 Z9 1 U1 0 U2 3 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 0010-2202 J9 COMBUST SCI TECHNOL JI Combust. Sci. Technol. PY 1991 VL 77 IS 4-6 BP 189 EP 202 DI 10.1080/00102209108951727 PG 14 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Energy & Fuels; Engineering GA FX172 UT WOS:A1991FX17200002 ER PT J AU NORTON, TS SMYTH, KC AF NORTON, TS SMYTH, KC TI LASER-INDUCED FLUORESCENCE OF CH IN A LAMINAR CH4 AIR DIFFUSION FLAME - IMPLICATIONS FOR DIAGNOSTIC MEASUREMENTS AND ANALYSIS OF CHEMICAL RATES SO COMBUSTION SCIENCE AND TECHNOLOGY LA English DT Article ID INDUCED SATURATED FLUORESCENCE; LOW-PRESSURE FLAME; RADICAL REACTIONS; NONPREMIXED FLAMES; HYDROCARBON FLAMES; METHANE; TEMPERATURE; KINETICS; MECHANISMS; COMBUSTION RP NORTON, TS (reprint author), NATL INST STAND & TECHNOL,CTR FIRE RES,GAITHERSBURG,MD 20899, USA. NR 70 TC 32 Z9 32 U1 0 U2 3 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 0010-2202 J9 COMBUST SCI TECHNOL JI Combust. Sci. Technol. PY 1991 VL 76 IS 1-3 BP 1 EP 20 DI 10.1080/00102209108951700 PG 20 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Energy & Fuels; Engineering GA FL631 UT WOS:A1991FL63100001 ER PT J AU WANG, CM AF WANG, CM TI APPROXIMATE CONFIDENCE-INTERVALS ON POSITIVE LINEAR-COMBINATIONS OF EXPECTED MEAN SQUARES SO COMMUNICATIONS IN STATISTICS-SIMULATION AND COMPUTATION LA English DT Article DE VARIANCE COMPONENT; COVERAGE PROBABILITIES ID VARIANCE-COMPONENTS AB Let n(i)S(i)2/theta-i for i = 1,2,..., q represent independently distributed chi-squared random variables with n(i) degrees of freedom. In this article, we develop new procedures for obtaining approximate confidence intervals on positive linear combinations of the theta-i. The proposed approximations, in many cases, are the weighted average of liberal and conservative confidence limits. By choosing the appropriate weight, which can be easily determined from data, we show that the proposed methods produce confidence intervals with confidence coefficients very close to the stated level. Numerical examples compare the performance to other approximations. C1 NATL INST STANDARDS & TECHNOL,DIV STAT ENGN,BOULDER,CO 80303. NR 15 TC 4 Z9 4 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 0361-0918 J9 COMMUN STAT SIMULAT JI Commun. Stat.-Simul. Comput. PY 1991 VL 20 IS 1 BP 81 EP 96 DI 10.1080/03610919108812940 PG 16 WC Statistics & Probability SC Mathematics GA FK425 UT WOS:A1991FK42500006 ER PT J AU BOISVERT, RF HOWE, SE KAHANER, DK AF BOISVERT, RF HOWE, SE KAHANER, DK TI THE GUIDE TO AVAILABLE MATHEMATICAL SOFTWARE PROBLEM CLASSIFICATION-SYSTEM SO COMMUNICATIONS IN STATISTICS-SIMULATION AND COMPUTATION LA English DT Article DE CLASSIFICATION SYSTEM; SOFTWARE DOCUMENTATION; MATHEMATICAL SOFTWARE; SOFTWARE ADVISORY SYSTEMS; SOFTWARE CATALOGS; STATISTICAL SOFTWARE AB A vast collection of reusable mathematical and statistical software is now available for use by scientists and engineers in their modeling efforts. This software represents a significant source of mathematical expertise, created and maintained at considerable expense. Unfortunately, the collection is so heterogeneous that it is a tedious and error-prone task simply to determine what software is available to solve a given problem. In mathematical problem-solving environments of the future such questions will be fielded by expert software advisory systems. One way for such systems to systematically associate available software with the problems they solve is to use a problem classification system. In this paper we describe a detailed tree-structured problem-oriented classification system appropriate for such use. C1 NATL INST STAND & TECHNOL,COMP & APPL MATH LAB,GAITHERSBURG,MD 20899. OI Boisvert, Ronald/0000-0002-4445-1044 NR 10 TC 8 Z9 9 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 0361-0918 J9 COMMUN STAT SIMULAT JI Commun. Stat.-Simul. Comput. PY 1991 VL 20 IS 4 BP 811 EP 842 DI 10.1080/03610919108812986 PG 32 WC Statistics & Probability SC Mathematics GA GQ616 UT WOS:A1991GQ61600001 ER PT J AU KACKER, RN LAGERGREN, ES HILL, MD WINNIE, WN CHIANG, CK FULLER, ER AF KACKER, RN LAGERGREN, ES HILL, MD WINNIE, WN CHIANG, CK FULLER, ER TI AN EFFICIENT EXPERIMENT TO STUDY SUPERCONDUCTING CERAMICS SO COMMUNICATIONS IN STATISTICS-THEORY AND METHODS LA English DT Article DE MATERIALS PROCESSING; DESIGN OF EXPERIMENTS; MIXTURE EXPERIMENTS; POLYNOMIAL APPROXIMATIONS; HIGH-TEMPERATURE SUPERCONDUCTORS; COLLINEARITY AB Materials formulation and processing research are important industrial processes and most materials know-how comes from physical experiments. Our impression, based on discussions with materials scientists, is that statistically planned experiments are infrequently used in materials research. This scientific and engineering area provides an excellent opportunity for both using the available techniques of statistically planned experiments, including mixture experiments, and identifying opportunities for collaborative research leading to further advances in statistical methods for scientists and engineers. This paper describes an application of Scheffe's (1958) simplex approach for mixture experiments to formulation of high-temperature superconducting compounds. This example has given us better appreciation of the needs of materials scientists and has provided us opportunities for further collaborative research. C1 NATL INST STANDARDS & TECHNOL,DIV STAT ENGN,GAITHERSBURG,MD 20899. NATL INST STANDARDS & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899. NR 7 TC 4 Z9 4 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 0361-0926 J9 COMMUN STAT THEORY JI Commun. Stat.-Theory Methods PY 1991 VL 20 IS 2 BP 441 EP 456 DI 10.1080/03610929108830508 PG 16 WC Statistics & Probability SC Mathematics GA FR390 UT WOS:A1991FR39000004 ER PT J AU VECCHIA, DF IYER, HK AF VECCHIA, DF IYER, HK TI MOMENTS OF THE QUARTIC ASSIGNMENT STATISTIC WITH AN APPLICATION TO MULTIPLE-REGRESSION SO COMMUNICATIONS IN STATISTICS-THEORY AND METHODS LA English DT Article DE DISTRIBUTION-FREE INFERENCE; MIXING INDEXES; MULTIPLE REGRESSION; PEARSON DISTRIBUTION; PERMUTATION TEST ID MRPP AB We present the first three exact moments of the symmetric quartic assignment statistic. Efficient computational formulas have been derived to overcome severe difficulties in third moment calculations. Two examples illustrate applications of the quartic assignment statistic: evaluation of significant "clustering" or "mixing"; and distribution-free tests for quality of several planar regression models. This article extends previous results on the cubic assignment statistic in Iyer and Vecchia (1989). C1 NATL INST STAND & TECHNOL,DIV STAT ENGN,BOULDER,CO 80303. COLORADO STATE UNIV,DEPT STAT,FT COLLINS,CO 80523. NR 12 TC 0 Z9 0 U1 1 U2 1 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 0361-0926 J9 COMMUN STAT THEORY JI Commun. Stat.-Theory Methods PY 1991 VL 20 IS 10 BP 3253 EP 3269 DI 10.1080/03610929108830700 PG 17 WC Statistics & Probability SC Mathematics GA GK939 UT WOS:A1991GK93900014 ER PT J AU STABENAU, EK HEMING, TA MITCHELL, JF AF STABENAU, EK HEMING, TA MITCHELL, JF TI RESPIRATORY, ACID-BASE AND IONIC STATUS OF KEMPS RIDLEY SEA-TURTLES (LEPIDOCHELYS-KEMPI) SUBJECTED TO TRAWLING SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-PHYSIOLOGY LA English DT Article ID GAS-EXCHANGE; CARETTA-CARETTA; CHELONIA-MYDAS; GREEN TURTLE; BLOOD; REST AB 1. Kemp's ridley sea turtles were placed in a commercial shrimp trawl equipped with a turtle excluder device (TED), resulting in a burst of apneic swimming and a brief bout of forced submergence (less-than-or-equal-to 7.3 min). 2. Trawl tests induced a significant non-respiratory (metabolic) acidosis; blood pH declined almost 0.4 units and plasma [lactate] increased 6-fold from pre- to post-trawl conditions. 3. Significant changes in blood parameters occurred regardless of the duration of forced submergence (range 2.7-7.3 min), suggesting apneic activity was a significant contributor to the observed acid-base imbalance. C1 NOAA,NATL MARINE FISHERIES SERV,GALVESTON LAB,GALVESTON,TX 77550. NATL MARINE FISHERIES SERV,PASCAGOULA LAB,PASCAGOULA,MS. RP STABENAU, EK (reprint author), UNIV TEXAS,MED BRANCH,PULMONARY RES LABS,GALVESTON,TX 77550, USA. NR 21 TC 31 Z9 32 U1 5 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0300-9629 J9 COMP BIOCHEM PHYS A JI Comp. Biochem. Physiol. A-Physiol. PY 1991 VL 99 IS 1-2 BP 107 EP 111 DI 10.1016/0300-9629(91)90243-6 PG 5 WC Biochemistry & Molecular Biology; Physiology; Zoology SC Biochemistry & Molecular Biology; Physiology; Zoology GA FF833 UT WOS:A1991FF83300020 ER PT J AU PLISETSKAYA, EM BUCHELLINARVAEZ, LI HARDY, RW DICKHOFF, WW AF PLISETSKAYA, EM BUCHELLINARVAEZ, LI HARDY, RW DICKHOFF, WW TI EFFECTS OF INJECTED AND DIETARY ARGININE ON PLASMA-INSULIN LEVELS AND GROWTH OF PACIFIC SALMON AND RAINBOW-TROUT SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-PHYSIOLOGY LA English DT Article ID GAIRDNERI R; COHO SALMON; SECRETION; NUTRITION; PANCREAS; HORMONES; RADIOIMMUNOASSAY; REQUIREMENTS; HISTIDINE; GLUCAGON AB 1. Amino acids (arginine, alanine and lysine) injected intraperitoneally 6.6-mu-mol/g body weight elevate, while histidine decreases plasma circulating levels of insulin in coho salmon (Oncorhynchus kisutch). 2. Insulinotropic action of arginine (0.03-6.6-mu-mol/g body weight) can be observed at 0.5-5.0 hr after injection. The effect of arginine is dependent on the season being more prolonged in winter when water temperature is low. 3. Insulinotropic action of arginine seems to be direct rather than through stimulation of glucagon or glucagon-like peptide secretion. 4. Feeding coho salmon, chinook salmon (O. tshawytscha) and rainbow trout (O. mykiss) diets supplemented with arginine caused elevation of plasma insulin levels. Arginine supplemented diets (20-30 g/kg dry diet over the content of regular diet) had a short-lasting stimulatory effect on fish growth, an effect which could be detected only in fingerlings. C1 NATL MARINE FISHERIES SERV,NW FISHERIES CTR,SEATTLE,WA 98112. RP PLISETSKAYA, EM (reprint author), UNIV WASHINGTON,SCH FISHERIES HF-15,SEATTLE,WA 98195, USA. NR 41 TC 62 Z9 65 U1 3 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0300-9629 J9 COMP BIOCHEM PHYS A JI Comp. Biochem. Physiol. A-Physiol. PY 1991 VL 98 IS 1 BP 165 EP 170 DI 10.1016/0300-9629(91)90595-4 PG 6 WC Biochemistry & Molecular Biology; Physiology; Zoology SC Biochemistry & Molecular Biology; Physiology; Zoology GA ET075 UT WOS:A1991ET07500029 ER PT J AU STEIN, JE HOM, T SANBORN, HR VARANASI, U AF STEIN, JE HOM, T SANBORN, HR VARANASI, U TI EFFECTS OF EXPOSURE TO A CONTAMINATED-SEDIMENT EXTRACT ON THE METABOLISM AND DISPOSITION OF 17-BETA-ESTRADIOL IN ENGLISH SOLE (PAROPHRYS-VETULUS) SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-PHARMACOLOGY TOXICOLOGY & ENDOCRINOLOGY LA English DT Article ID C-14 POLYCHLORINATED-BIPHENYLS; RAINBOW-TROUT; INVITRO METABOLISM; H-3 BENZOPYRENE; LIVER-MICROSOMES; SALMO-GAIRDNERI; ESTRADIOL; XENOBIOTICS; ENZYMES; ASSAY AB 1. Effects of a contaminated sediment extract on the disposition and metabolism of H-3-17-beta-estradiol in juvenile English sole and on plasma levels of endogenous estradiol in gravid females were examined. 2. Plasma estradiol levels were reduced in both extract-treated juvenile and gravid-sole compared to controls, and in juvenile sole this decrease preceeded an increase in bile levels of H-3-17-beta-estradiol. 3. Extract treatment had no significant effect on types or proportions of 17-beta-estradiol metabolites or levels of related hepatic enzymes. 4. Thus, lower plasma estradiol levels in extract-treated sole were apparently due to alterations in physiological factors (e.g. increased bile flow) and not to enhanced metabolism of 17-beta-estradiol. RP STEIN, JE (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES CTR,DIV ENVIRONM CONSERVAT,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. NR 32 TC 18 Z9 20 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0742-8413 J9 COMP BIOCHEM PHYS C JI Comp. Biochem. Physiol. C-Pharmacol. Toxicol. Endocrinol. PY 1991 VL 99 IS 1-2 BP 231 EP 240 DI 10.1016/0742-8413(91)90104-2 PG 10 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism; Toxicology; Zoology SC Biochemistry & Molecular Biology; Endocrinology & Metabolism; Toxicology; Zoology GA FF834 UT WOS:A1991FF83400040 ER PT J AU GALLAGHER, L AF GALLAGHER, L TI DATABASE-MANAGEMENT STANDARDS - STATUS AND APPLICABILITY SO COMPUTER STANDARDS & INTERFACES LA English DT Article DE ANSI; DATABASE; DATA MODEL; FIPS; ISO; NETWORK; NDL; RDA; RELATIONAL; STANDARD; SQL AB This article presents the current status of existing and emerging ISO, ANSI, and FIPS standards for database management, specifically Database Languages NDL and SQL and Remote Database Access (RDA). It describes the general content of each standard and discusses its applicability, availability, completeness, maturity, stability, existing usage, and known limitations. Where appropriate, it also addresses the availability of conformance test suites and future plans for enhancements and follow-on standardization efforts. RP GALLAGHER, L (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5489 J9 COMP STAND INTER JI Comput. Stand. Interfaces PY 1991 VL 12 IS 3 BP 185 EP 192 DI 10.1016/0920-5489(91)90081-A PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA GT413 UT WOS:A1991GT41300002 ER PT J AU LIBES, D AF LIBES, D TI MODELING DYNAMIC SURFACES WITH OCTREES SO COMPUTERS & GRAPHICS LA English DT Article AB Past uses of octrees have been for representation of static objects. We discuss extensions necessary to model dynamic surfaces. One particularly important aspect of this is the ability to represent expanding surfaces that grow to be arbitrarily large. Our enhanced octree does exactly this, and models contraction as well. The ability to represent dynamic surfaces allows us to apply octrees to new problems which could not previously have been modeled with static octrees. One such problem is the entropy of random surfaces. Using dynamic octrees, we produced a simulation of self-avoiding random surfaces using Monte Carlo techniques. RP LIBES, D (reprint author), NATL INST STAND & TECHNOL,INTEGRATED SYST GRP,GAITHERSBURG,MD 20899, USA. NR 6 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0097-8493 J9 COMPUT GRAPH JI Comput. Graph. PY 1991 VL 15 IS 3 BP 383 EP 387 DI 10.1016/0097-8493(91)90008-6 PG 5 WC Computer Science, Software Engineering SC Computer Science GA GG886 UT WOS:A1991GG88600008 ER PT J AU AHARON, P AF AHARON, P TI RECORDERS OF REEF ENVIRONMENT HISTORIES - STABLE ISOTOPES IN CORALS, GIANT CLAMS, AND CALCAREOUS ALGAE SO CORAL REEFS LA English DT Article ID EASTERN JAVA SEA; HALIMEDA BIOHERMS; MONTASTREA-ANNULARIS; SCLERACTINIAN CORALS; BIOLOGICAL CARBONATES; PLEISTOCENE CORAL; NEW-GUINEA; OXYGEN; FRACTIONATION; C-13 AB Time-series delta-O-18 and delta-C-13 records from cohabiting massive coral Porites australiensis and giant clam Tridacna gigas from the Great Barrier Reef of Australia, and from calcareous green algae in a core through modern Halimeda bioherm accreting in the eastern Java Sea, provide insights into the complex links between environmental factors and stable isotopes imprinted in these reef skeletal materials. The aragonitic coral and giant clam offer 20 years and 15 years of growth history, respectively. The giant clam yields mean delta-O-18 and delta-C-13 values of -0.5 +/- 0.5 parts-per-thousand and 2.2 +/- 0.2 parts-per-thousand (n = 67), which agree well with the predicted equilibrium values. The coral yields mean delta-O-18 and delta-C-13 values of -5.6 +/- 0.5 parts-per-thousand and -1.8 +/- 0.7 parts-per-thousand (n = 84), offering a striking example of kinetic and metabolic fractionation effects. Although both the coral and giant clam harbor symbionts and were exposed to a uniform ambient environment during their growth histories, their distinct isotopic compositions demonstrate dissimilar calcification pathways. The delta-O-18 records contain periodicities corresponding to the alternating annual density bands revealed by X-radiography and optical transmitted light. Attenuation of the delta-O-18 seasonal amplitudes occurring in the giant clam record 8 years after skeletal growth commenced is attributed to a changeover from fast to slow growth rates. Extreme seasonal delta-O-18 amplitudes of up to 2.2 parts-per-thousand discerned in both the coral and giant clam records exceed the equivalent seasonal temperature contrast in the reef environment, and are caused by the combined effect of rainfall and evaporation during the monsoon and dry seasons, respectively. Thus in addition of being useful temperature recorders, reef skeletal material of sufficient longevity, such as Porites and Tridacna, may also indicate rainfall variations. Changing growth rates, determined from the annual growth bands, may exert a primary control on the coral delta-C-13 record which shows a remarkable negative shift of 1.7 parts-per-thousand over its growth history, by comparison with only 0.15 parts-per-thousand negative shift in the contemporaneous giant clam record. Use of coral delta-C-13 records as proxies of fossil fuel CO2 uptake by the ocean must be regarded with caution. The delta-O-18 and delta-C-13 records from Halimeda are remarkably uniform over 1000 years of bioherm accretion history (delta-O-18 = -1.7 +/- 0.2 parts-per-thousand; delta-C-13 = 3.9 +/- 0.1 parts-per-thousand, n = 28), in spite of variable Mg-calcite cements present in the utricles. Most of the cement infilling is probably syndepositional, and both the Halimeda aragonite and the Mg-calcite cements containing 12.3 mole % MgCO3 are deposited in isotopic equilibrium. Therefore, in favorable circumstances these algal skeletal remains may act as the shallow water analogs of benthic foraminifera in deep sea sediments in recording ambient sea water isotopic composition and temperature. RP LOUISIANA STATE UNIV, DEPT NOAA, BATON ROUGE, LA 70803 USA. NR 75 TC 103 Z9 108 U1 3 U2 14 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0722-4028 EI 1432-0975 J9 CORAL REEFS JI Coral Reefs PY 1991 VL 10 IS 2 BP 71 EP 90 DI 10.1007/BF00571826 PG 20 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA GD743 UT WOS:A1991GD74300004 ER PT J AU DUBE, WP SPARKS, LL SLIFKA, AJ AF DUBE, WP SPARKS, LL SLIFKA, AJ TI THERMAL-CONDUCTIVITY OF EVACUATED PERLITE AT LOW-TEMPERATURES AS A FUNCTION OF LOAD AND LOAD HISTORY SO CRYOGENICS LA English DT Article DE THERMAL CONDUCTIVITY; MATERIALS CHARACTERIZATION; PHYSICAL PROPERTIES AB Perlite, a powdered insulation, is commonly used in large cryogenic storage dewars. When these dewars are thermally cycled, the perlite in the evacuated space between the inner and outer vessels of the dewar experiences a changing mechanical load due to thermal expansion and contraction of the inner vessel. Thermal conductivity data were obtained using a boil-off calorimeter. The apparent thermal conductivity of evacuated perlite increases strongly with applied load. Hysteretic behaviour of the conductivity was observed when perlite was subjected to cyclic mechanical loading. RP DUBE, WP (reprint author), NATL INST STANDARDS TECHNOL,CTR CHEM TECHNOL,DIV CHEM ENGN SCI,325 BROADWAY,BOULDER,CO 80303, USA. RI Dube, William/I-1658-2013 OI Dube, William/0000-0003-1286-4087 NR 5 TC 6 Z9 6 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD JAN PY 1991 VL 31 IS 1 BP 3 EP 6 DI 10.1016/0011-2275(91)90183-W PG 4 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA EU179 UT WOS:A1991EU17900001 ER PT J AU HAMANN, IM SWIFT, JH AF HAMANN, IM SWIFT, JH TI A CONSISTENT INVENTORY OF WATER MASS FACTORS IN THE INTERMEDIATE AND DEEP PACIFIC-OCEAN DERIVED FROM CONSERVATIVE TRACERS SO DEEP-SEA RESEARCH PART A-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID NORTH PACIFIC; TROPICAL AREAS; FLOW PATTERNS; SOUTH-PACIFIC; CIRCULATION; SALINITY; CURRENTS AB Estimates of the characteristics and proportional importance of water mass factors are determined by exploratory multivariate Q-mode factor analysis (QMFA) of Pacific Ocean hydrographic data from the region north of 30-degrees-S. The inter-tracer ratios between potential temperature, salinity, the calculated parameters "NO" and "PO" and silicate are used to establish a matrix of similarity coefficients between all station locations. Its rotated eigenvectors ("factors") are viewed as distinct water types of the system. On individual key density surfaces QMFA shows that the spatial distribution of relative contributions from the primary factors can be linked to known or suspected water types and their subsequent spreading. The minor factors reflect smaller perturbations of the dominating ratios. Another QMFA was done in three dimensions by combining all density layers to determine factors derived from diapycnal as well as isopycnal property gradients. Two primary factors represent the opposing vertical temperature and salinity-nutrients gradient: "a deep water melange", which concentrates in the Northeast Pacific (maximum where sigma-1 greater-than-or-equal-to 31.93), and a "subtropical thermocline" factor (maximum on sigma-theta = 25.80) centered in the subtropical gyres. The spatially uneven decrease of relative contribution from a "shallow" factor as one moves down from the upper to the lower thermocline suggests areas where the exchange with the "deeper" factor may be enhanced. C1 UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,PHYS OCEANOGR RES DIV,A-030,LA JOLLA,CA 92093. RP HAMANN, IM (reprint author), NOAA,NATL MARINE FISHERIES,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 68 TC 4 Z9 4 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0198-0149 J9 DEEP-SEA RES PY 1991 VL 38 SU 1 BP S129 EP S169 PG 41 WC Oceanography SC Oceanography GA GD479 UT WOS:A1991GD47900008 ER PT J AU TAFT, BA HAYES, SP FRIEDERICH, GE CODISPOTI, A AF TAFT, BA HAYES, SP FRIEDERICH, GE CODISPOTI, A TI FLOW OF ABYSSAL WATER INTO THE SAMOA PASSAGE SO DEEP-SEA RESEARCH PART A-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article ID SOUTH-PACIFIC AB On the TEW Expedition a hydrographic section was made in June 1987 across the Samoa Passage; in addition, south of the Passage, a section was made through the Penrhyn and Samoa Basins and the Tonga Trench. In this paper the flow of the deep water with North Atlantic Deep Water and Antarctic characteristics below 3500 m is discussed. Temperature-salinity-oxygen relationships show a similarity of properties between the Tonga Trench and western boundary of the Samoa Basin. The salinity and silicate date show distinct signatures of North Atlantic Deep Water and Antarctic Bottom Water flowing into the Samoa Passage. Salinity and silicate data in the Samoa Basin and Passage are similar to those measured on the STYX Expedition (1968). Oxygen data show that the water along the Samoa Basin's western boundary is oxygen-rich relative to water in the eastern Basin, but with no oxygen maximum in deep water, as was observed on STYX. Geostrophic flow, based on a reference surface determined from T-S, O2 curves, shows strong northward components (> 10 cm s-1) in the Samoa Passage. On the west side of the Passage the flow was southward (< 1 cm s-1) below 4600 m. This flow reversal was associated with a reversal of the sign of the horizontal potential temperature gradient and also with lower values of oxygen, salinity and silicate next to the boundary. The northward transport of Lower Circumpolar Water between the Manihiki Plateau and the Tonga Trench was 12.3 +/- 3.6 x 10(6) m3 s-1; the flow into the Samoa Passage was 6.0 +/- 1.1 x 10(6) m3 s-1. Assuming that only flow above 4800 m can exit the northern Samoa Basin because of topographic restrictions, the total northward transport into the north Tokelau Basin was 9.6 +/- 1.8 x 10(6) m3 s-1. C1 WOCE INT PROJECT OFF, IOS DEACON LAB, WORMLEY GU8 5UB, SURREY, ENGLAND. MONTEREY BAY AQUARIUM RES INST, PACIFIC GROVE, CA 93950 USA. RP NOAA, PACIFIC MARINE ENVIRONM LAB, 7600 SAND POINT WAY NE, SEATTLE, WA 98115 USA. NR 17 TC 26 Z9 26 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0198-0149 J9 DEEP-SEA RES PY 1991 VL 38 SU 1 BP S103 EP S128 DI 10.1016/S0198-0149(12)80007-0 PG 26 WC Oceanography SC Oceanography GA GD479 UT WOS:A1991GD47900007 ER PT J AU BOEHLERT, GW YAMADA, J AF BOEHLERT, GW YAMADA, J TI INTRODUCTION TO THE SYMPOSIUM ON ROCKFISHES SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Editorial Material ID SEBASTES-SCHLEGELI; GENUS SEBASTES; SCORPAENIDAE; ENERGETICS; LARVAE C1 UNIV HAWAII,JOINT INST MARINE & ATMOSPHER RES,HONOLULU,HI 96822. HOKKAIDO UNIV,FAC FISHERIES,PHYSIOL & ECOL LAB,HAKODATE,HOKKAIDO 041,JAPAN. RP BOEHLERT, GW (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 49 TC 13 Z9 16 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD JAN PY 1991 VL 30 IS 1-2 BP 9 EP 13 DI 10.1007/BF02296871 PG 5 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA EU355 UT WOS:A1991EU35500002 ER PT J AU LENARZ, WH ECHEVERRIA, TW AF LENARZ, WH ECHEVERRIA, TW TI SEXUAL DIMORPHISM IN SEBASTES SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE ROCKFISH; BEHAVIOR; FEEDING; MORPHOLOGY; SCORPAENIDAE ID GENUS SEBASTES; ROCKFISH; REPRODUCTION; CALIFORNIA; GROWTH; SIZE AB Sexual dimorphism and factors that may cause it were investigated in 34 species of the genus Sebastes. Sexual dimorphism in standard length and morphometric characters are fairly common in rockfish. In many species males are shorter than females. However in males head legth, width of orbit, interorbital width, length of upper jaw, longest pectoral fin ray and longest dorsal spine tend to be larger at a specified size than in females. Water-column species tend to be more dimorphic than demersal species. We suggest that the observed differences in dimorphism in standard length may be related to differences in mating and territorial behavior. Dimorphisms in morphometric measurements may be related to compensation in feeding ability for reduced standard length of males, mating and territorial behavior. RP NATL MARINE FISHERIES SERV, SW FISHERIES CTR, TIBURON LAB, 3150 PARADISE DR, TIBURON, CA 94920 USA. NR 33 TC 8 Z9 11 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0378-1909 EI 1573-5133 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD JAN PY 1991 VL 30 IS 1-2 BP 71 EP 80 DI 10.1007/BF02296878 PG 10 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA EU355 UT WOS:A1991EU35500009 ER PT J AU BOEHLERT, GW KUSAKARI, M YAMADA, J AF BOEHLERT, GW KUSAKARI, M YAMADA, J TI OXYGEN-CONSUMPTION OF GESTATING FEMALE SEBASTES-SCHLEGELI - ESTIMATING THE REPRODUCTIVE COSTS OF LIVEBEARING SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article; Proceedings Paper CT US-JAPAN SYMP ON THE REPRODUCTION AND EARLY LIFE HISTORY IN SEBASTES : ROCKFISHES OF THE GENUS SEBASTES CY JUN, 1989 CL EAST WEST CTR, HONOLULU, HI HO EAST WEST CTR DE VIVIPARITY; EMBRYOS; TELEOST; RESPIRATION ID GENUS SEBASTES; DYNAMIC ACTION; ROCKFISH; FISH; ENERGETICS; GROWTH; FOOD; SCORPAENIDAE; DIPLOPROA; FECUNDITY AB During gestation, live-bearing fishes incur physiological energy costs, including provision of energy and respiratory gases to the developing embryos and removal of waste products. Fecundity in the genus Sebastes is high, and the ovaries represent a significant portion of the weight of gestating females. In this study, we compare oxygen consumption of gestating females with non-gestating females and males of kurosoi, Sebastes schlegeli, to estimate these costs. Oxygen consumption by pregnant females is significantly higher than that of males and immature females at similar sizes and weights. We estimate that a 1.5 kg gestating female consumes 68% more oxygen than a non-gestating fish during the 51.5-day period of gestation. Such an increase in oxygen consumption rates may have important implications to the metabolic scope of gestating females. The additional oxygen consumed by gestating females is greater than that predicted for the embryos alone, suggesting that costs of increased gill ventilation, ionic and osmotic regulation and cardiac output are relatively high. Such energetic costs represent a quantifiable expense of the viviparous mode of reproduction in Sebastes as compared with oviparous species. C1 UNIV HAWAII,JOINT INST MARINE & ATMOSPHER RES,HONOLULU,HI 96822. HOKKAIDO INST MARICULTURE,SHIKABE,HOKKAIDO,JAPAN. HOKKAIDO UNIV,FAC MINERAL CHEM,PHYSIOL & ECOL LAB,HAKODATE,HOKKAIDO 041,JAPAN. RP BOEHLERT, GW (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 41 TC 20 Z9 21 U1 0 U2 8 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD JAN PY 1991 VL 30 IS 1-2 BP 81 EP 89 DI 10.1007/BF02296879 PG 9 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA EU355 UT WOS:A1991EU35500010 ER PT J AU ELDRIDGE, MB WHIPPLE, JA BOWERS, MJ JARVIS, BM GOLD, J AF ELDRIDGE, MB WHIPPLE, JA BOWERS, MJ JARVIS, BM GOLD, J TI REPRODUCTIVE-PERFORMANCE OF YELLOWTAIL ROCKFISH, SEBASTES-FLAVIDUS SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE REPRODUCTION; SEX RATIO; MATURITY; FECUNDITY; GONADOGENESIS; SCORPAENIDAE ID MATURITY AB Field and laboratory studies were conducted for 3 years on the yellowtail rockfish, Sebastes flavidus, from Cordell Bank, California, in order to characterize the reproduction of this species whose northern stocks have declined. Research findings included reversal of the sex ratios and male-female ages and sizes at age throughout the annual cycle, heavier and longer females at age than males after sexual maturation, maturation of females at 6 and males at 8 years, long reproductive lifespans, distinct male and female gonadosomatic index patterns over the annual cycle, age- and size-specific fecundity, no difference between potential and realized fecundity and the seasonal changes associated with gonadogenesis. The reproductive profile of the Cordell Bank yellowtail rockfish provided a base for comparison with northern populations that appeared to differ, especially in age and size. RP NATL MARINE FISHERIES SERV, SW FISHERIES CTR, TIBURON LAB, 3150 PARADISE DR, TIBURON, CA 94920 USA. NR 30 TC 32 Z9 32 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0378-1909 EI 1573-5133 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD JAN PY 1991 VL 30 IS 1-2 BP 91 EP 102 DI 10.1007/BF02296880 PG 12 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA EU355 UT WOS:A1991EU35500011 ER PT J AU CONTE, FP TAKANO, K TAKEMURA, A BOEHLERT, GW AF CONTE, FP TAKANO, K TAKEMURA, A BOEHLERT, GW TI ONTOGENY OF THE SODIUM-PUMP IN EMBRYOS OF ROCKFISH OF THE GENUS SEBASTES SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article; Proceedings Paper CT US-JAPAN SYMP ON THE REPRODUCTION AND EARLY LIFE HISTORY IN SEBASTES : ROCKFISHES OF THE GENUS SEBASTES CY JUN, 1989 CL EAST WEST CTR, HONOLULU, HI HO EAST WEST CTR DE NA; K-ATPASE; TRANSPORTING ATPASE; FISH LARVAE; DEVELOPMENT ID TELEOST CLINUS-SUPERCILIOSUS; FUNDULUS-HETEROCLITUS; ENERGETICS; BERMUDAE; SEAWATER; SALINITY; BALANCE; LARVAE; FLUID; EGGS AB The purpose of the present investigation was to determine at what stages of embryonic development the sodium pump (Na +, K + -activated ATP phosphohydrolase, EC 3.6.1.3) appears and whether the ontogeny of the sodium pump plays a role in the matrotrophic viviparity of Sebastes. Early larval stages (stages 1-14) had embryonic tissues nearly devoid of Na, K-ATPase activity. After epiboly, tissues from embryos taken from both species, S. schlegeli and S. taczanowskii, had significant levels of enzymatic activity coincident with the appearance of neuronal tissue in the head fold (stages 15-20). Maximal levels of specific activities of the enzyme were reached with the onset of the vascular circulation and the opening of the buccal cavity together with maturation of the midgut and hindgut regions of the intestinal tract (stages 26 and 28). Ouabain, a specific inhibitor of Na, K-ATPase, was used to measure survival of embryos placed in different seawater concentrations under in vitro conditions. The most sensitive stages to external ouabain were 26-30. These findings support the hypothesis that the intestinal tract is functional prior to gestation and could be transporting important nutritive material found in maternal ovarian fluid. C1 HOKKAIDO UNIV,FAC HLTH EDUC,HAKODATE,HOKKAIDO 041,JAPAN. NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES CTR,HONOLULU LAB,HONOLULU,HI 96822. UNIV HAWAII,JOINT INST MARINE & ATMOSPHER RES,HONOLULU,HI 96822. RP CONTE, FP (reprint author), OREGON STATE UNIV,DEPT ZOOL,CORVALLIS,OR 97331, USA. NR 32 TC 7 Z9 7 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD JAN PY 1991 VL 30 IS 1-2 BP 127 EP 133 DI 10.1007/BF02296883 PG 7 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA EU355 UT WOS:A1991EU35500014 ER PT J AU YOKLAVICH, MM BOEHLERT, GW AF YOKLAVICH, MM BOEHLERT, GW TI UPTAKE AND UTILIZATION OF C-14 GLYCINE BY EMBRYOS OF SEBASTES-MELANOPS SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article; Proceedings Paper CT US-JAPAN SYMP ON THE REPRODUCTION AND EARLY LIFE HISTORY IN SEBASTES : ROCKFISHES OF THE GENUS SEBASTES CY JUN, 1989 CL EAST WEST CTR, HONOLULU, HI HO EAST WEST CTR DE ROCKFISH; VIVIPARITY; NUTRITION; PISCES; SCORPAENIDAE ID TELEOST CLINUS-SUPERCILIOSUS; MATERNAL-FETAL RELATIONSHIP; VIVIPAROUS TELEOST; ADAPTATIONS; LARVAE; SCORPAENIDAE; PERCIFORMES; ENERGETICS; SCHLEGELI; FISHES AB The ability of embryos of the viviparous scorpaenid Sebastes melanops to take up nutrients from an exogenous substrate was demonstrated by incubating embryos at various stages of development (18-30 days after fertilization) in C-14-labeled glycine for 24 h. Uptake was highest for embryos at the latest stages (28-30 days) and increased at a linear rate during the incubation period. Nutrient uptake was not time dependent in embryos at the early stages (18-22 days). Nutrient utilization by S. melanops embryos was measured by the oxidation of C-14-labeled glycine to (CO2)-C-14. The amount of respired (CO2)-C-14 by the oldest embryos increased significantly at a linear rate over the 24 h incubation period. There was no evidence of nutrient utilization by the youngest embryos. The developmental changes we observed in the uptake and utilization of exogenous glycine are supported by our previous findings that the oldest embryos have fully developed mouths and guts, and require additional nutrition from intraovarian sources at this stage of development. C1 NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115. NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES CTR,HONOLULU LAB,HONOLULU,HI 96822. UNIV HAWAII,JOINT INST MARINE & ATMOSPHER RES,HONOLULU,HI 96822. NR 24 TC 12 Z9 12 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD JAN PY 1991 VL 30 IS 1-2 BP 147 EP 153 DI 10.1007/BF02296885 PG 7 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA EU355 UT WOS:A1991EU35500016 ER PT J AU SHIMIZU, M KUSAKARI, M YOKLAVICH, MM BOEHLERT, GW YAMADA, J AF SHIMIZU, M KUSAKARI, M YOKLAVICH, MM BOEHLERT, GW YAMADA, J TI ULTRASTRUCTURE OF THE EPIDERMIS AND DIGESTIVE-TRACT IN SEBASTES EMBRYOS, WITH SPECIAL REFERENCE TO THE UPTAKE OF EXOGENOUS NUTRIENTS SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article; Proceedings Paper CT US-JAPAN SYMP ON THE REPRODUCTION AND EARLY LIFE HISTORY IN SEBASTES : ROCKFISHES OF THE GENUS SEBASTES CY JUN, 1989 CL EAST WEST CTR, HONOLULU, HI HO EAST WEST CTR DE VIVIPARITY; NUTRITION; HORSERADISH PEROXIDASE; RUTHENIUM RED; PINOCYTOSIS; ROCKFISH; PISCES; SCORPAENIDAE ID INTRACELLULAR DIGESTION; HORSERADISH-PEROXIDASE; VIVIPAROUS TELEOST; ENERGETICS; EPITHELIUM; SCHLEGELI; LARVAE; CELLS AB Ultrastructural features of the epidermis and rectum were studied in Sebastes schlegeli and S. melanops during the late stages of embryonic development, to confirm uptake of maternal substances. Ruthenium red (RR) and horseradish peroxidase (HRP) were used at fixation and in live embryos, respectively. Epidermal tissue of embryos after developmental stage 24 comprised two squamous cell layers. The outer, thinner cells and their intercellular spaces were easily infiltrated with RR, but the inner cells had no RR deposition. The HRP was not incorporated into the epidermis except in a few outer cells, which had well-developed microvillous projections of cytoplasm. Sacciform cells, chloride cells, and mucous cells distributed in the inner layer but protruding to the epidermal surface had no intracellular RR and HRP depositions. The rectal cells of embryos at about developmental stage 28 had many globular inclusions containing electron-dense substances. The rectal cells were found to take up and digest HRP actively. It is suggested that the embryonic epidermis is structurally loose and takes up low weight molecules, while rectal cells, after the opening of the mouth, actively ingest exogenous, high weight molecules. C1 HOKKAIDO FISHERIES EXPTL STN,YOICHI,HOKKAIDO 046,JAPAN. OREGON STATE UNIV,COLL OCEANOG,NEWPORT,OR 97365. NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES CTR,HONOLULU LAB,HONOLULU,HI 96822. UNIV HAWAII,JOINT INST MARINE & ATMOSPHER RES,HONOLULU,HI 96822. OREGON STATE UNIV,CTR MARINE SCI,NEWPORT,OR 97365. RP SHIMIZU, M (reprint author), HOKKAIDO UNIV,FAC MINERAL CHEM,HAKODATE,HOKKAIDO 041,JAPAN. NR 18 TC 17 Z9 18 U1 1 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD JAN PY 1991 VL 30 IS 1-2 BP 155 EP 163 DI 10.1007/BF02296886 PG 9 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA EU355 UT WOS:A1991EU35500017 ER PT J AU KENDALL, AW AF KENDALL, AW TI SYSTEMATICS AND IDENTIFICATION OF LARVAE AND JUVENILES OF THE GENUS SEBASTES SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article; Proceedings Paper CT US-JAPAN SYMP ON THE REPRODUCTION AND EARLY LIFE HISTORY IN SEBASTES : ROCKFISHES OF THE GENUS SEBASTES CY JUN, 1989 CL EAST WEST CTR, HONOLULU, HI HO EAST WEST CTR DE EARLY LIFE-HISTORY DESCRIPTIONS; TAXONOMY; SCORPAENIDAE ID FAMILY SCORPAENIDAE; SOUTHERN-CALIFORNIA; BAJA-CALIFORNIA; OREGON; FLAVIDUS; MELANOPS; ROCKFISH AB Current information on systematics and morphology of larvae and juveniles of Sebastes is reviewed, as are intrageneric relationships among the many species of the genus. Although some subgenera may remain after a cladistic analysis of the genus, others are probably artificial groupings of species that have convergent morphologies because of similar ecology. The relationships of Sebastes to other scorpaeniform fishes as well as the relationships of scorpaeniforms to other fishes are not resolved. Of the 102 species of Sebastes worldwide, 69 species have been illustrated as preflexion larvae, 35 as postflexion larvae and 65 as pelagic juveniles. Morphological characters of each of these stages were used to compare species, group them by similar appearances and then compare these groupings with existing subgenera. Some pigment patterns of preflexion larvae were rather consistent among species within certain subgenera but quite variable among species in other subgenera. Postflexion larvae fell into 11 groups based on pigment, head spines and body shape. These groups were not closely aligned with the subgeneric assignments of the component species. On the basis of pigment patterns of pelagic juveniles, six groups were evident, but the specific composition of these groups bore little resemblance to either the larval or subgeneric groups. RP KENDALL, AW (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115, USA. NR 51 TC 46 Z9 48 U1 3 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD JAN PY 1991 VL 30 IS 1-2 BP 173 EP 190 DI 10.1007/BF02296888 PG 18 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA EU355 UT WOS:A1991EU35500019 ER PT J AU SEEB, LW KENDALL, AW AF SEEB, LW KENDALL, AW TI ALLOZYME POLYMORPHISMS PERMIT THE IDENTIFICATION OF LARVAL AND JUVENILE ROCKFISHES OF THE GENUS SEBASTES SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article; Proceedings Paper CT US-JAPAN SYMP ON THE REPRODUCTION AND EARLY LIFE HISTORY IN SEBASTES : ROCKFISHES OF THE GENUS SEBASTES CY JUN, 1989 CL EAST WEST CTR, HONOLULU, HI HO EAST WEST CTR DE TAXONOMY; ELECTROPHORESIS; SCORPAENIDAE ID STARCH-GEL ELECTROPHORESIS; MITOCHONDRIAL-DNA; FISH; HETEROZYGOSITY; EXPRESSION; EVOLUTION; PATTERNS; ENZYMES; LOCUS; EGGS AB Many Sebastes larvae lack distinguishing morphological characteristics, particularly in the size range of 8-12 mm. Complete descriptions are available for only about 12 of the 72 northeastern Pacific species. Allozyme analysis has been very useful in the identification of adult Sebastes, and our objective was to determine whether it could be equally useful in the identification of larvae and juveniles. Individually dissected tissues (muscle, liver, eye, heart) were assayed from Sebastes juveniles (> 30 mm total length (TL)). The allozyme activity and resolution from the juveniles for 33 loci were indistinguishable from those obtained from adults. Larvae (5-12 mm TL) were prepared whole, and their allozyme expression varied by individual size and locus. A total of 32 loci were resolved from the larger (9-12 mm TL) larvae, but the allozyme activity was reduced in smaller (5-8 mm TL) larvae. Adequate resolution from the smaller larvae was obtained for 28 loci, a sufficient number to identify individuals to species. Allozyme analysis is a valuable technique to identify the species of Sebastes larvae and to aid in developing morphological and meristic descriptions. Other DNA-level techniques will likely further increase our ability to identify Sebastes larvae. C1 SO ILLINOIS UNIV,DEPT ZOOL,CARBONDALE,IL 62901. NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,SEATTLE,WA 98115. RP SEEB, LW (reprint author), SO ILLINOIS UNIV,FISHERIES RES LAB,CARBONDALE,IL 62901, USA. NR 59 TC 21 Z9 21 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD JAN PY 1991 VL 30 IS 1-2 BP 191 EP 201 DI 10.1007/BF02296889 PG 11 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA EU355 UT WOS:A1991EU35500020 ER PT J AU MOSER, HG BOEHLERT, GW AF MOSER, HG BOEHLERT, GW TI ECOLOGY OF PELAGIC LARVAE AND JUVENILES OF THE GENUS SEBASTES SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article; Proceedings Paper CT US-JAPAN SYMP ON THE REPRODUCTION AND EARLY LIFE HISTORY IN SEBASTES : ROCKFISHES OF THE GENUS SEBASTES CY JUN, 1989 CL EAST WEST CTR, HONOLULU, HI HO EAST WEST CTR DE SCORPAENIDAE; ROCKFISH; DISTRIBUTION; ICHTHYOPLANKTON ID CALIFORNIA CURRENT SYSTEM; SOUTHERN-CALIFORNIA; BAJA-CALIFORNIA; FISH LARVAE; ROCKFISH SCORPAENIDAE; VERTICAL-DISTRIBUTION; FAMILY SCORPAENIDAE; REDFISH SEBASTES; BLACK ROCKFISH; OREGON COAST AB Pelagic larvae and juveniles of the genus Sebastes are widely distributed in the continental shelf and slope waters of subarctic to temperate oceans, with greatest abundance in the Northern Hemisphere. We review the ecology and distribution of these planktonic and micronektonic life stages in relation to oceanographic conditions. Special attention is paid to the west coast of North America, where abundance of larvae from samples collected during 1951-1981 is described. After transformation, the pelagic juveniles are widely distributed, often at great distances from benthic adult habitats. These stages are most frequently distributed in either midwater or near-surface habitats; this dichotomy may require different strategies for successful recruitment. C1 NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES CTR,HONOLULU LAB,HONOLULU,HI 96822. UNIV HAWAII,JOINT INST MARINE & ATMOSPHER RES,HONOLULU,HI 96822. RP MOSER, HG (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES CTR,POB 271,LA JOLLA,CA 92038, USA. NR 95 TC 82 Z9 84 U1 3 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD JAN PY 1991 VL 30 IS 1-2 BP 203 EP 224 DI 10.1007/BF02296890 PG 22 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA EU355 UT WOS:A1991EU35500021 ER PT J AU BOEHLERT, GW LOVE, MS WOURMS, JP YAMADA, J AF BOEHLERT, GW LOVE, MS WOURMS, JP YAMADA, J TI A SUMMARY OF THE SYMPOSIUM ON ROCKFISHES AND RECOMMENDATIONS FOR FUTURE-RESEARCH SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article; Proceedings Paper CT US-JAPAN SYMP ON THE REPRODUCTION AND EARLY LIFE HISTORY IN SEBASTES : ROCKFISHES OF THE GENUS SEBASTES CY JUN, 1989 CL EAST WEST CTR, HONOLULU, HI HO EAST WEST CTR C1 UNIV HAWAII,JOINT INST MARINE & ATMOSPHER RES,HONOLULU,HI 96822. UNIV CALIF SANTA BARBARA,INST MARINE SCI,SANTA BARBARA,CA 93106. CLEMSON UNIV,DEPT BIOL SCI,CLEMSON,SC 29634. HOKKAIDO UNIV,FAC FISHERIES,PHYSIOL & ECOL LAB,HAKODATE,HOKKAIDO 041,JAPAN. RP BOEHLERT, GW (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 4 TC 4 Z9 4 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD JAN PY 1991 VL 30 IS 1-2 BP 273 EP 280 DI 10.1007/BF02296894 PG 8 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA EU355 UT WOS:A1991EU35500025 ER PT J AU SIMIC, MG AF SIMIC, MG TI DNA DAMAGE, ENVIRONMENTAL TOXICANTS, AND RATE OF AGING SO ENVIRONMENTAL CARCINOGENESIS REVIEWS-PART C OF JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH LA English DT Review ID OXIDATIVE DAMAGE; HYDROXYL RADICALS; THYMINE GLYCOL; TUMOR PROMOTER; RADIATION; REDUCTION; MITOCHONDRIAL; ANTIOXIDANT; MUTAGENESIS; MECHANISMS RP SIMIC, MG (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 72 TC 11 Z9 11 U1 0 U2 1 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 SN 1059-0501 J9 ENVIRON CARCIN ECO R JI Environ. Carcinog. Ecotoxical. Rev.-Pt. C J. Env. Sci. Health PY 1991 VL 9 IS 1 BP 113 EP 153 PG 41 WC Oncology; Environmental Sciences; Toxicology SC Oncology; Environmental Sciences & Ecology; Toxicology GA GR008 UT WOS:A1991GR00800005 ER PT J AU MURCHELANO, RA WOLKE, RE AF MURCHELANO, RA WOLKE, RE TI NEOPLASMS AND NONNEOPLASTIC LIVER-LESIONS IN WINTER FLOUNDER, PSEUDO-PLEURONECTES-AMERICANUS, FROM BOSTON HARBOR, MASSACHUSETTS SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article ID MICROGADUS-TOMCOD WALBAUM; HUDSON RIVER ESTUARY; ATLANTIC TOMCOD; AQUATIC ANIMALS; HEALTH MONITORS; RAINBOW-TROUT; PUGET-SOUND; NEW-YORK; FISH; HEPATOCYTES AB A variety of neoplasms and nonneoplastic hepatic lesions have been noted in winter flounder, Pseudopleuronectes americanus, from Boston Harbor, Massachusetts. Inflammatory lesions include cholangiitis, pericholangiitis, pericholangial fibrosis, hepatitis, and pancreatitis. Necrotic lesions consist essentially of focal coagulative necrosis and a distinctive vacuolated cell lesion of the hepatic parenchyma. The most conspicuous and numerous proliferative lesion is macrophage aggregate hyperplasia and hypertrophy. Preneoplastic lesions include principally basophilic foci of cellular alteration and hepatocellular adenoma. Carcinomas consist of several morphologic varieties: hepatocarcinoma, cholangiocarcinoma, and anaplastic adenocarcinoma. The pathogenesis of the lesions observed is discussed with respect to anthropogenically introduced chemical contaminants and the resistant hepatocyte model of hepatocarcinogenesis. This study, and others of bottom-living food fish with enzootic neoplastic disease, warrants further evaluation, particularly with respect to possible bioaccumulation of chemical contaminants in edible tissues. RP MURCHELANO, RA (reprint author), NATL MARINE FISHERIES SERV,NE FISHERIES CTR,WOODS HOLE LAB,WOODS HOLE,MA 02543, USA. NR 43 TC 65 Z9 68 U1 0 U2 1 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD JAN PY 1991 VL 90 BP 17 EP 26 DI 10.2307/3430841 PG 10 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA FD603 UT WOS:A1991FD60300004 PM 1646709 ER PT J AU FARLEY, CA PLUTSCHAK, DL SCOTT, RF AF FARLEY, CA PLUTSCHAK, DL SCOTT, RF TI EPIZOOTIOLOGY AND DISTRIBUTION OF TRANSMISSIBLE SARCOMA IN MARYLAND SOFTSHELL CLAMS, MYA-ARENARIA, 1984-1988 SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article ID SOFT-SHELL CLAM; MYTILUS-EDULIS; NEOPLASIA; PREVALENCE; DISORDERS; WATERS; SITES AB Seasonal and geographic studies of transmissible sarcoma in Maryland softshell clams, Mya arenaria, were carried out from 1984 to 1988. Three major epizootics occurred in our sampling location during this time, resulting in prevalences as high as 90%, with comparable mortalities in other high prevalence areas. The disease invaded populations of large adult clams first, later spreading to the small juvenile clam populations. An apparent 2-year cycle was noted with varying seasonal effects. Affected sites tended to be in the main stem of Chesapeake Bay north of Tangier Sound, primarily in the areas where the major harvesting occurs. Several sites, mostly in upstream locations, were consistently free of disease. The epizootiological study supports the interpretation that the disease is infectious exclusively to this species. Regression analysis between sarcoma prevalence and contaminant levels in clam tissues showed a significant correlation (p = 0.0001) between chlordane levels and this disease. No correlations were found with other contaminants that were analyzed. RP FARLEY, CA (reprint author), NATL MARINE FISHERIES SERV,MARYLAND DEPT NAT RESOURCES,OXFORD COOPERAT LAB,OXFORD,MD 21654, USA. NR 29 TC 31 Z9 32 U1 0 U2 1 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD JAN PY 1991 VL 90 BP 35 EP 41 DI 10.2307/3430843 PG 7 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA FD603 UT WOS:A1991FD60300006 PM 2050081 ER PT J AU OCONNOR, TP AF OCONNOR, TP TI CONCENTRATIONS OF ORGANIC CONTAMINANTS IN MOLLUSKS AND SEDIMENTS AT NOAA NATIONAL STATUS AND TREND SITES IN THE COASTAL AND ESTUARINE UNITED-STATES SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS AB Mean concentrations of PAHs, PCBs, and DDT in mollusks and sediments at sites in the National Status and Trends Program (NST) are distributed in log-normal fashion. The dry weight-based chlorinated organic concentrations in mollusks generally exceed those in nearby sediments by an order of magnitude. PAHs are found at similar concentrations in sediments and mollusks. Highest concentrations of PCBs and DDT in mollusks are in the ranges of 1000 to 4000 ng/g (dry) and 400 to 1000 ng/g (dry), respectively. The highest PAH concentrations in sediments are in the 10,000 to 50,000 ng/g (dry) range. While higher concentrations of contaminants can be found by sampling localized hot spots, the NST data represent the distribution of concentrations over general areas of the coastal United States. RP OCONNOR, TP (reprint author), NOAA,DIV OCEAN ASSESSMENTS,N-OMA32,6001 EXECUT BLDG,ROCKVILLE,MD 20852, USA. NR 12 TC 33 Z9 34 U1 0 U2 2 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD JAN PY 1991 VL 90 BP 69 EP 73 DI 10.2307/3430847 PG 5 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA FD603 UT WOS:A1991FD60300010 PM 1904811 ER PT J AU VARANASI, U STEIN, JE AF VARANASI, U STEIN, JE TI DISPOSITION OF XENOBIOTIC CHEMICALS AND METABOLITES IN MARINE ORGANISMS SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article ID SOLE PAROPHRYS-VETULUS; SEDIMENT-ASSOCIATED XENOBIOTICS; C-14 POLYCHLORINATED-BIPHENYLS; SALMON ONCORHYNCHUS-KISUTCH; PSEUDOPLEURONECTES-AMERICANUS; SIMULTANEOUS EXPOSURE; 9-C-14 PHENANTHRENE; H-3 BENZOPYRENE; WINTER FLOUNDER; PUGET-SOUND AB Studies with several bottom fish species from urban waterways show that of the identified xenobiotic chemicals in bottom sediments, polycyclic aromatic hydrocarbons (PAHs) are the most strongly associated with the prevalence of liver lesions, including neoplasms. Accordingly, there is concern about the transfer of contaminants, such as PAHs, from aquatic species to humans. Because PAHs exert their toxicity only after being biotransformed, increasing attention has been focused on the ability of aquatic organisms to metabolize these chemicals. Overall, the results of both laboratory and field studies show that generally low levels (nanograms per gram wet weight) of a few low molecular weight PAHs may be present in edible tissue of fish from contaminated areas and that high molecular weight PAHs, such as the carcinogen benzo(a)pyrene, will rarely be detected because of extensive metabolism. Additionally, the results from a few studies suggest that even though interactions between xenobiotics can affect both biochemical and physiological systems to alter the disposition of PAHs in fish, these interactions do not markedly change the relative proportions of metabolites to parent PAH in tissues. Thus, these studies clearly demonstrate that to obtain some insight into the questions of whether there is any risk to human health from consuming fish and crustaceans from urban areas, techniques must be developed that measure metabolites of carcinogens, such as PAHs, in edible tissue. Initial attempts may focus on semiquantitative methods that permit rapid assessment of the level of metabolites in edible tissues of fish and crustaceans from many urban areas. Based on information from such screening studies, further refinement in methodology leading to identification of specific compounds may be needed because certain metabolites may not be as toxic or carcinogenic as others. A scientifically sound database on a broad spectrum of contaminants and their metabolites in aquatic species is needed before we can adequately address the question of bioavailability or food chain transfer of these compounds to humans. RP VARANASI, U (reprint author), NOAA,NW FISHERIES CTR,DIV ENVIRONM CONSERVAT,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. NR 33 TC 84 Z9 85 U1 0 U2 18 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD JAN PY 1991 VL 90 BP 93 EP 100 DI 10.2307/3430850 PG 8 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA FD603 UT WOS:A1991FD60300013 PM 2050086 ER PT J AU CHAPMAN, PM LONG, ER SWARTZ, RC DEWITT, TH PASTOROK, R AF CHAPMAN, PM LONG, ER SWARTZ, RC DEWITT, TH PASTOROK, R TI SEDIMENT TOXICITY TESTS, SEDIMENT CHEMISTRY AND BENTHIC ECOLOGY DO PROVIDE NEW INSIGHTS INTO THE SIGNIFICANCE AND MANAGEMENT OF CONTAMINATED SEDIMENTS - A REPLY SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Letter ID RHEPOXYNIUS-ABRONIUS; INFAUNAL AMPHIPOD; WATER C1 NOAA,DIV OCEAN ASSESSMENTS,SEATTLE,WA 98115. US EPA,HATFIELD MARINE SCI CTR,NEWPORT,OR. OREGON STATE UNIV,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365. PTI ENVIRONM SCI INC,BELLEVUE,WA. RP CHAPMAN, PM (reprint author), EVS CONSULTANTS LTD,N VANCOUVER,BC,CANADA. RI Mason, Robert/A-6829-2011 NR 19 TC 20 Z9 20 U1 0 U2 1 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PY 1991 VL 10 IS 1 BP 1 EP 4 PG 4 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA EU280 UT WOS:A1991EU28000001 ER PT J AU LANDRUM, PF EADIE, BJ FAUST, WR AF LANDRUM, PF EADIE, BJ FAUST, WR TI TOXICOKINETICS AND TOXICITY OF A MIXTURE OF SEDIMENT-ASSOCIATED POLYCYCLIC AROMATIC-HYDROCARBONS TO THE AMPHIPOD DIPOREIA SP SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE POLYCYCLIC AROMATIC HYDROCARBONS; PONTOPOREIA; DIPOREIA SP; TOXICOKINETICS; SEDIMENTS ID PONTOPOREIA-HOYI; ORGANIC-CHEMICALS; BIOAVAILABILITY; WATERS AB Amphipods, Diporeia sp., were exposed to a reference sediment dosed with two radio-labeled polycyclic aromatic hydrocarbons (PAHs) and sediments dosed with a mixture of PAHs at four concentrations: 21.4, 41.0, 119.6, and 327.0 nmol g-1 dry sediment, as the molar sum of the PAH congeners. Diporeia sp. were sampled for mortality and toxicokinetics for up to 26 d. Significant sediment avoidance was observed at the highest dose out to 6 d of exposure. The toxicity for the mixture was 38 +/- 3% after 19 d of exposure at the highest dose, 327 nmol g-1 dry sediment as the molar sum of the PAHs. The measured organism concentration required to produce the mortality at day 19 was 2.9-mu-mol g-1 as the sum of the bioaccumulated PAHs. The uptake clearance (g dry sediment g-1 organism h-1) from sediments for the radiotracers increased with dose to an apparent plateau. Uptake clearance is the conditional constant relating the contaminant flux into the organism to the contaminant concentration in the referenced environmental compartment, in this case the sediment. This enhanced bioavailability with dose occurred even in the absence of overt effects and in the absence of changes in the measured partition coefficients for phenanthrene (273 +/- 98) and pyrene (540 +/- 212), between the freely dissolved radiotracers in interstitial water and the sediment particles. These changes in bioavailability with changes in PAH concentration suggest that predictions of bioaccumulation of PAH congeners from sediments under different field concentration conditions will not be possible with standard partitioning relationships. RP LANDRUM, PF (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 32 TC 79 Z9 82 U1 1 U2 7 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PY 1991 VL 10 IS 1 BP 35 EP 46 DI 10.1897/1552-8618(1991)10[35:TATOAM]2.0.CO;2 PG 12 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA EU280 UT WOS:A1991EU28000005 ER PT J AU LANDRUM, PF STUBBLEFIELD, CR AF LANDRUM, PF STUBBLEFIELD, CR TI ROLE OF RESPIRATION IN THE ACCUMULATION OF ORGANIC XENOBIOTICS BY THE AMPHIPOD DIPOREIA SP SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE UPTAKE KINETICS; HEXACHLOROBIPHENYL; PAH; DIPOREIA SP; RESPIRATION ID TROUT SALMO-GAIRDNERI; ACUTE TOXICITY SYNDROMES; PONTOPOREIA-HOYI; CARDIOVASCULAR RESPONSES; OXYGEN-UPTAKE; NAPHTHALENE; WATER; FISH; BIOTRANSFORMATION; BIOAVAILABILITY AB Accumulation of hydrophobic organic xenobiotics is though to occur by passive diffusion across the respiratory membrane of aquatic organisms. This route has been confirmed with fish. However, aquatic invertebrates tend to remove organic xenobiotics from water much more efficiently than oxygen, based on the relative uptake clearances. Uptake clearance is the rate coefficient that describes the volume of water stripped of analyte per g of organism per h. For the amphipod Diporeia sp., formerly classified as Pontoporeia hoyi, ratios of the contaminant uptake clearances to oxygen clearance were essentially constant at 3.9 +/- 0.4 (X + SE) for benzo[a]pyrene (BaP), 3.8 +/- 0.3 for hexachlorobiphenyl (HCBP), and 4.2 +/- 0.6 for phenanthrene (Phe). Therefore, based on the membrane transport efficiencies of nonpolar xenobiotics (60-80%) and oxygen (approximately 63%) in fish, and the uptake clearance for organic xenobiotics by Diporeia sp., either xenobiotics are accumulated through routes other than across the respiratory membrane or the accumulation efficiency of oxygen from water is much lower in amphipods than it is in fish. The variability in the uptake clearance for both BaP and HCBP was best described by regressions with the surface area-to-volume ratio, whereas the uptake clearance for the more hydrophilic Phe was best described by a total surface area relationship. RP LANDRUM, PF (reprint author), NOAA, GREAT LAKES ENVIRONM RES LAB, 2205 COMMONWEALTH BLVD, ANN ARBOR, MI 48105 USA. NR 34 TC 22 Z9 22 U1 1 U2 3 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0730-7268 EI 1552-8618 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PY 1991 VL 10 IS 8 BP 1019 EP 1028 DI 10.1897/1552-8618(1991)10[1019:RORITA]2.0.CO;2 PG 10 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA FZ385 UT WOS:A1991FZ38500006 ER PT J AU PITTS, WM AF PITTS, WM TI EFFECTS OF GLOBAL DENSITY RATIO ON THE CENTERLINE MIXING BEHAVIOR OF AXISYMMETRICAL TURBULENT JETS SO EXPERIMENTS IN FLUIDS LA English DT Article ID RAYLEIGH LIGHT-SCATTERING; ENTRAINMENT; TEMPERATURE; TRANSPORT; MOMENTUM; FLOWS AB Measurements, utilizing Rayleigh light scattering, of time-averaged concentration and unmixedness have been made along the centerlines of axisymmetric turbulent jets formed from six pairs of jet and ambient gases. Jet to ambient density ratios range from 0.14 to 5.11. Findings are compared with predictions of an approx. similarity analysis and with extensive previous literature measurements. It is shown that virtual origins for plots of inverse time-averaged concentration are strongly dependent on global density ratio. Unmixedness values first grow with increasing distance from the jet source and then achieve an asymptote. The flow distance required to reach this asymptote is a strong function of density ratio. RP PITTS, WM (reprint author), NATL INST STAND & TECHNOL,CTR FIRE RES,GAITHERSBURG,MD 20899, USA. RI tian, hongzhou/M-7867-2015 OI tian, hongzhou/0000-0003-1402-3855 NR 50 TC 64 Z9 65 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0723-4864 J9 EXP FLUIDS JI Exp. Fluids PY 1991 VL 11 IS 2-3 BP 125 EP 134 PG 10 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA FM330 UT WOS:A1991FM33000006 ER PT J AU PITTS, WM AF PITTS, WM TI REYNOLDS-NUMBER EFFECTS ON THE MIXING BEHAVIOR OF AXISYMMETRICAL TURBULENT JETS SO EXPERIMENTS IN FLUIDS LA English DT Article AB Measurements of time-averaged jet fluid mass fraction and unmixedness are reported along the centerlines of axisymmetric jets having Reynolds numbers (Re) covering a range of 3,950-11,880. Jet gases investigated are propane, carbon tetrafluoride, and sulfur hexafluoride. The slopes for the fall off of inverse centerline mass fraction with distance are found to be independent of Re for moderate downstream distances, but virtual origins for the data are shown to move downstream with increasing Re. Unmixedness measurements show that flows with higher Re require longer flow distances to achieve asymptotic behavior. Results of other investigations reported in the literature are discussed which support the conclusions of this work. The relationship between the centerline mixing and entrainment behaviors of these flows is explored. RP PITTS, WM (reprint author), NATL INST STAND & TECHNOL,CTR FIRE RES,GAITHERSBURG,MD 20899, USA. NR 21 TC 47 Z9 47 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0723-4864 J9 EXP FLUIDS JI Exp. Fluids PY 1991 VL 11 IS 2-3 BP 135 EP 141 PG 7 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA FM330 UT WOS:A1991FM33000007 ER PT J AU WILLIAMS, PA CLARK, NA ROS, MB WALBA, DM WAND, MD AF WILLIAMS, PA CLARK, NA ROS, MB WALBA, DM WAND, MD TI LARGE ELECTROCLINIC EFFECT IN NEW LIQUID-CRYSTAL MATERIAL SO FERROELECTRICS LA English DT Article; Proceedings Paper CT 3RD INTERNATIONAL CONF ON FERROELECTRIC LIQUID CRYSTALS ( FLC-91 ) CY JUN 23-28, 1991 CL BOULDER, CO SP CANON, CHISSO, USA, RES OFF, HOFFMANN LA ROCHE, FERROELECT, FUJITSU LABS, GORDON & BREACH SCI PUBL, HOECHST, IBM, MAT SCI & TECHNOL ID AC PHASE-CHANGE C1 UNIV COLORADO,DEPT PHYS,CONDENSED MATTER LAB,BOULDER,CO 80309. UNIV COLORADO,CTR OPTOELECTR COMP SYST,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. DISPLAYTECH INC,BOULDER,CO 80301. RP WILLIAMS, PA (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. RI Clark, Noel/E-9011-2010; Walba, David/F-7284-2013; OI , /0000-0003-4416-1036 NR 6 TC 37 Z9 37 U1 0 U2 1 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 0015-0193 J9 FERROELECTRICS PY 1991 VL 121 IS 1-4 BP 143 EP 146 DI 10.1080/00150199108217618 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GV774 UT WOS:A1991GV77400015 ER PT J AU CLARK, NA WALBA, DM AF CLARK, NA WALBA, DM TI PROCEEDINGS OF THE 3RD INTERNATIONAL-CONFERENCE ON FERROELECTRIC LIQUID-CRYSTALS - JUNE 23-28, 1991 - BOULDER, COLORADO, USA - PREFACE SO FERROELECTRICS LA English DT Editorial Material RP CLARK, NA (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. RI Clark, Noel/E-9011-2010; Walba, David/F-7284-2013 NR 0 TC 0 Z9 0 U1 0 U2 1 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 0015-0193 J9 FERROELECTRICS PY 1991 VL 121 IS 1-4 BP R17 EP R17 PG 1 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA GV774 UT WOS:A1991GV77400001 ER PT J AU GALLAWA, RL GOYAL, IC GHATAK, AK AF GALLAWA, RL GOYAL, IC GHATAK, AK TI OPTICAL WAVE-GUIDE ANALYSIS USING MODIFIED AIRY FUNCTIONS SO FIBER AND INTEGRATED OPTICS LA English DT Article AB We review a little-used but powerful method of solving the scalar wave equation. It uses a modification of the well-known Airy functions, which are easily calculated on desktop computers. The techniques are reminiscent of the WKBJ methodology, but the solution, although approximate, is much more useful than the traditional WKBJ solution and can be used with almost as much ease. The method is extremely powerful but, to our knowledge, is not used in the optics community. It is useful in analyzing integrated optical waveguide components. RP GALLAWA, RL (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 0146-8030 J9 FIBER INTEGRATED OPT JI Fiber Integr. Opt. PY 1991 VL 10 IS 1 BP 1 EP 10 DI 10.1080/01468039108201601 PG 10 WC Optics SC Optics GA GJ691 UT WOS:A1991GJ69100001 ER PT J AU BABRAUSKAS, V AF BABRAUSKAS, V TI EFFECTIVE MEASUREMENT TECHNIQUES FOR HEAT, SMOKE, AND TOXIC FIRE GASES SO FIRE SAFETY JOURNAL LA English DT Article AB The latest techniques which have been developed for the measurement of heat, smoke, and toxic gas emissions from fires are reviewed. The current objective of minimizing apparatus dependence of the data is emphasized. Forms of data and their units are outlined. Differences between data obtained in large-scale and in bench-scale tests are discussed, and areas where further research is needed are indicated. RP BABRAUSKAS, V (reprint author), NATL INST STAND & TECHNOL,CTR FIRE RES,GAITHERSBURG,MD 20899, USA. NR 0 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0379-7112 J9 FIRE SAFETY J JI Fire Saf. J. PY 1991 VL 17 IS 1 BP 13 EP 26 DI 10.1016/0379-7112(91)90010-V PG 14 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA FG686 UT WOS:A1991FG68600002 ER PT J AU GROSS, D AF GROSS, D TI ESTIMATING AIR LEAKAGE THROUGH DOORS FOR SMOKE CONTROL SO FIRE SAFETY JOURNAL LA English DT Article; Proceedings Paper CT SYMP ON THE SCIENCE OF BUILDING FIRE SAFETY, IN HONOR OF PROFESSOR OVE PETTERSSON ON HIS RETIREMENT CY MAY 24, 1989 CL LUND, SWEDEN AB A generalized, nondimensional relationship for flow through defined narrow gaps is used to predict leakage flow past closed door assemblies. Typical gap shapes considered include straight-through single or double sharp (90-degrees) bends; baffle at leading edge; comb-type labyrinth; and filament brush seal. Applications for prediction and design appropriate to smoke control systems are indicated. RP GROSS, D (reprint author), NATL INST STAND & TECHNOL,CTR FIRE RES,GAITHERSBURG,MD 20899, USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0379-7112 J9 FIRE SAFETY J JI Fire Saf. J. PY 1991 VL 17 IS 2 BP 171 EP 177 DI 10.1016/0379-7112(91)90040-6 PG 7 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA FQ656 UT WOS:A1991FQ65600013 ER PT J AU PEACOCK, RD BABRAUSKAS, V AF PEACOCK, RD BABRAUSKAS, V TI ANALYSIS OF LARGE-SCALE FIRE TEST DATA SO FIRE SAFETY JOURNAL LA English DT Article AB Large-scale room fire testing has evolved from simple fire performance measurements such as intensity and duration of 'room fires' to sophisticated measurements to understand the properties which cause the fire. This paper provides a overview of typical calculations, based upon published research results, that are used at the Center for Fire Research and elsewhere for the analysis of a large-scale room fire test. Analysis of large-scale fire test data requires the development of a series of algorithms that combine individual measurements to produce the desired physical quantity. A set of algorithms for the analysis of fire test data based upon published research results is described. Included are fire-specific calculations such as smoke and gas analysis, layer temperature and interface position, mass loss and flows, and rate of heat release. Examples of the application of the calculations are provided. RP PEACOCK, RD (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD, USA. NR 0 TC 13 Z9 15 U1 1 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0379-7112 J9 FIRE SAFETY J JI Fire Saf. J. PY 1991 VL 17 IS 5 BP 387 EP 414 DI 10.1016/0379-7112(91)90019-U PG 28 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA GB025 UT WOS:A1991GB02500003 ER PT J AU DEMARTINI, EE AF DEMARTINI, EE TI ANNUAL VARIATIONS IN FECUNDITY, EGG SIZE, AND THE GONADAL AND SOMATIC CONDITIONS OF QUEENFISH SERIPHUS-POLITUS (SCIAENIDAE) SO FISHERY BULLETIN LA English DT Article ID CLUPEA-HARENGUS-PALLASI; EL-NINO; NORTHERN ANCHOVY; FISH EGGS; GROWTH; FREQUENCY; WEIGHT; CALIFORNIA; HYPOTHESES; ABUNDANCE AB Batch fecundity, weight-specific fecundity (number of eggs per gram somatic weight), size of ripe ovarian eggs, and the somatic and gonadal conditions of adult female queenfish Seriphus politus were estimated for five spawning seasons during an 8-year (1979-86) period. The effects of female somatic weight were evaluated in analyses of covariance comparing batch fecundity, egg size, and gonadal condition among years. Batch fecundity was positively (and allometrically) related to female somatic weight. Fecundities were remarkably similar during four of the five years evaluated. After adjustment for annual differences in female size, fecundities were still significantly lower (by about one-fifth) during 1984, a major El Nino year, compared with the preceding (1979-80) or following (1985-86) pairs of years. Gonadal condition also was uniquely low in 1984. The 1984 declines in fecundity and gonadal condition co-occurred with low somatic condition during 1984, particularly for larger females. Mean size (diameter, dry weight) of eggs was indistinguishable among years. There was a positive relation between egg size and female body size, and a general decline in egg size as the spawning season advanced for females of all sizes. Likely links between declines in fecundity, gonadal and somatic condition, and the crash in planktonic production during the 1982-84 El Nino are discussed. RP DEMARTINI, EE (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 49 TC 24 Z9 27 U1 2 U2 7 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JAN PY 1991 VL 89 IS 1 BP 9 EP 18 PG 10 WC Fisheries SC Fisheries GA FE840 UT WOS:A1991FE84000002 ER PT J AU KIMURA, DK LYONS, JJ AF KIMURA, DK LYONS, JJ TI BETWEEN-READER BIAS AND VARIABILITY IN THE AGE-DETERMINATION PROCESS SO FISHERY BULLETIN LA English DT Article ID YELLOWTAIL ROCKFISH; VALIDATION; OTOLITHS AB At the Alaska Fisheries Science Center, one in five age readings produced for routine stock assessments are re-aged independently by a second age-reader. The Center now has a large database of repeated age readings that covers a variety of groundfish species and years. The purpose of this paper is to point out the problems and utility of interpreting such a database. The main problem of interpretation is fundamental, and relates to the fact that the true age of a fish is seldom known. Nevertheless, from a pragmatic point of view, these data can still provide useful insights into the age-determination process. Data from six marine fish species are used to show the overall levels of between-reader bias, agreement, and variability that have occurred on production age readings. Other uses for these data include objectively ranking the relative difficulty in ageing different species, maintaining quality control, examining between-reader differences in ageing criteria, and evaluating the possible importance of between-reader bias and variability in later analysis and modeling applications. Assuming reader bias is negligible, modeling results presented here indicate that estimated percentage agreements are consistent with the hypothesis that age determinations are normally distributed with a constant coefficient of variation over relatively wide age ranges. This result supports use of the coefficient of variation for measuring variability in age precision studies. RP KIMURA, DK (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 14 TC 107 Z9 114 U1 1 U2 9 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JAN PY 1991 VL 89 IS 1 BP 53 EP 60 PG 8 WC Fisheries SC Fisheries GA FE840 UT WOS:A1991FE84000006 ER PT J AU LEDGERWOOD, RD THROWER, FP DAWLEY, EM AF LEDGERWOOD, RD THROWER, FP DAWLEY, EM TI DIEL SAMPLING OF MIGRATORY JUVENILE SALMONIDS IN THE COLUMBIA RIVER ESTUARY SO FISHERY BULLETIN LA English DT Article AB Beach and purse seine catches at Jones Beach, River kilometer 75, were used to examine diel movement patterns of juvenile chinook salmon Oncorhynchus tshawytscha, coho salmon O. kisutch, and steelhead O. mykiss as they migrated downstream in the Columbia River estuary. The patterns were monitored during five 24-hour periods in 1978, 1979, and 1980, and compared with patterns obtained from extensive morning-hour sampling conducted during 1979-83. Diel catch patterns were generally consistent among the sampling periods and there was reasonable agreement with morning-hour sampling. However, diel movement was different than that reported for salmonids in other river systems and in other locations in the Columbia River. The times and lateral position of greatest downstream movement which provided the largest catches of salmonid juveniles were as follows: sunrise to early afternoon nearshore for subyearling chinook salmon, sunrise to early afternoon midriver for yearling chinook salmon, midmorning to early evening nearshore and sunrise to early afternoon midriver for coho salmon, and noon to early evening midriver for steelhead. Decreased movement during darkness was apparent for all salmonids. No relationship between tidal cycle and catch was evident from either beach or purse seine sampling. C1 NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,AUKE BAY LAB,AUKE BAY,AK 99821. RP LEDGERWOOD, RD (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,COASTAL ZONE & ESTUARINE STUDIES DIV,BLVD E,SEATTLE,WA 98112, USA. NR 23 TC 14 Z9 14 U1 0 U2 4 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JAN PY 1991 VL 89 IS 1 BP 69 EP 78 PG 10 WC Fisheries SC Fisheries GA FE840 UT WOS:A1991FE84000008 ER PT J AU MATLOCK, GC NELSON, WR JONES, RS GREEN, AW CODY, TJ GUTHERZ, E DOERZBACHER, J AF MATLOCK, GC NELSON, WR JONES, RS GREEN, AW CODY, TJ GUTHERZ, E DOERZBACHER, J TI COMPARISON OF 2 TECHNIQUES FOR ESTIMATING TILEFISH, YELLOWEDGE GROUPER, AND OTHER DEEP-WATER FISH POPULATIONS SO FISHERY BULLETIN LA English DT Article ID HUDSON SUBMARINE-CANYON; LOPHOLATILUS-CHAMAELEONTICEPS; MID-ATLANTIC; ABUNDANCE; GEORGIA; MORTALITY; BEHAVIOR; GROWTH; MEXICO; GULF AB Tilefish Lopholatilus chamaeleonticeps and yellowedge grouper Epinephelus flavolimbatus are deepwater fishes and targets of a relatively recent bottom longline fishery in the Gulf of Mexico. They are long-lived, slow growing, have very limited movements and distribution, and are susceptible to longlines. However, population size and life-history parameter estimates are generally unknown for Gulf fish. This study compared two methods for estimating population sizes to determine the most cost-effective one for use on long-term fishery-independent stock assessments. Bottom longlines were used to deplete fish from a small area, and a regression of catch per effort on cumulative catch was used to estimate the area's population prior to fishing. The population was also estimated by counting fish burrows from a submersible and expanding the mean number per unit area by the study site's area after correcting for the number of occupied burrows. Longlines and submersibles provided significantly different estimates of tilefish populations, the only species for which estimates could be compared. Longline estimates were probably more accurate because errors in area estimation and double counting were evident in submersible data. Longlines were less expensive to operate ($5000 vs. $8000 per day) and they afforded collection of size, age, and sex data on each fish caught. These data were not available from the submersible. Longlines could be used more cost-effectively than submersibles in determining long-term population changes. However, direct observation of fish behavior was not available from longlines, but was from the submersible. Submersibles also provide data on habitat and gear assessment, including deployment, efficiency, bait predation, and potential catch loss during retrieval. C1 NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,MIAMI,FL 33149. UNIV TEXAS,INST MARINE SCI,PORT ARANSAS,TX 78373. TEXAS PARKS & WILDLIFE DEPT,COASTAL FISHERIES BRANCH,ROCKPORT,TX 78382. NOAA,NATL MARINE FISHERIES SERV,MISSISSIPPI LAB,PASCAGOULA,MS 39567. RP MATLOCK, GC (reprint author), TEXAS PARKS & WILDLIFE DEPT,DIV FISHERIES,4200 SMITH SCH RD,AUSTIN,TX 78744, USA. NR 32 TC 11 Z9 11 U1 3 U2 8 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JAN PY 1991 VL 89 IS 1 BP 91 EP 99 PG 9 WC Fisheries SC Fisheries GA FE840 UT WOS:A1991FE84000010 ER PT J AU OVERHOLTZ, WJ MURAWSKI, SA MICHAELS, WL AF OVERHOLTZ, WJ MURAWSKI, SA MICHAELS, WL TI IMPACT OF COMPENSATORY RESPONSES ON ASSESSMENT ADVICE FOR THE NORTHWEST ATLANTIC MACKEREL STOCK SO FISHERY BULLETIN LA English DT Article ID DAILY RATION; FOOD; WESTERN AB Annual assessments of the Northwest Atlantic mackerel stock have occurred every year since 1973, providing useful advice to fishery managers involved in the decision making process for this important pelagic resource. Since 1985, assessment advice based on an F0.1 management strategy has indicated that catches in the 300,000 mt range are feasible because stock biomass has increased greatly after the collapse of the fishery in the mid-1970s. However, indications from previous research are that compensatory processes are very important, so a stochastic simulation model with density-dependent growth, maturity, and natural mortality was constructed to study how these mechanisms might affect our ability to provide short- and long-term advice for this important stock. Model results suggest that our present assessments may be too optimistic relative to yield projections and that minimum spawning-stock biomass levels may be difficult to maintain even with an F0.1 fishing strategy. Model results also reveal that natural mortality rates are probably much higher than previously thought and are important in determining trends in abundance in this stock. RP OVERHOLTZ, WJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,WOODS HOLE LAB,WOODS HOLE,MA 02543, USA. NR 37 TC 15 Z9 17 U1 0 U2 3 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JAN PY 1991 VL 89 IS 1 BP 117 EP 128 PG 12 WC Fisheries SC Fisheries GA FE840 UT WOS:A1991FE84000012 ER PT J AU POLOVINA, JJ AF POLOVINA, JJ TI EVALUATION OF HATCHERY RELEASES OF JUVENILES TO ENHANCE ROCKFISH STOCKS, WITH APPLICATION TO PACIFIC-OCEAN PERCH SEBASTES-ALUTUS SO FISHERY BULLETIN LA English DT Article AB The equilibrium contribution of hatchery-released juveniles to a rockfish fishery is evaluated by using a yield-per-recruit model. Hatchery-released juveniles may be worth up to an estimated US$0.16 per juvenile to the fishery. The use of hatchery releases to restore a depleted population of Pacific ocean perch Sebastes alutus is examined with the Deriso-Schnute model. This model indicates that hatchery releases have the potential to substantially increase a stock's yield and rate of recovery during the recovery period. RP POLOVINA, JJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,2570 DOLE ST,HONOLULU,HI 96822, USA. NR 15 TC 6 Z9 6 U1 0 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JAN PY 1991 VL 89 IS 1 BP 129 EP 136 PG 8 WC Fisheries SC Fisheries GA FE840 UT WOS:A1991FE84000013 ER PT J AU SOMERTON, DA AF SOMERTON, DA TI DETECTING DIFFERENCES IN FISH DIETS SO FISHERY BULLETIN LA English DT Article C1 NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,HONOLULU LAB,HONOLULU,HI 96822. NR 10 TC 11 Z9 13 U1 0 U2 6 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JAN PY 1991 VL 89 IS 1 BP 167 EP 169 PG 3 WC Fisheries SC Fisheries GA FE840 UT WOS:A1991FE84000017 ER PT J AU DIZDAROGLU, M AF DIZDAROGLU, M TI CHEMICAL DETERMINATION OF FREE RADICAL-INDUCED DAMAGE TO DNA SO FREE RADICAL BIOLOGY AND MEDICINE LA English DT Review DE HYDROXYL RADICAL; GAS CHROMATOGRAPHY MASS SPECTROMETRY; MAMMALIAN CHROMATIN; DNA BASE PRODUCTS; DNA-PROTEIN CROSS-LINKS; HYDROGEN PEROXIDE; IONIZING RADIATION; METAL IONS; SUPEROXIDE DISMUTASE; FREE RADICAL AB Free radical-induced damage to DNA in vivo can result in deleterious biological consequences such as the initiation and promotion of cancer. Chemical characterization and quantitation of such DNA damage is essential for an understanding of its biological consequences and cellular repair. Methodologies incorporating the technique of gas chromatography/mass spectrometry (GC/MS) have been developed in recent years for measurement of free radical-induced DNA damage. The use of GC/MS with selected-ion monitoring (SIM) facilitates unequivocal identification and quantitation of a large number of products of all four DNA bases produced in DNA by reactions with hydroxyl radical, hydrated electron, and H atom. Hydroxyl radical-induced DNA-protein cross-links in mammalian chromatin, and products of the sugar moiety in DNA are also unequivocally identified and quantitated. The sensitivity and selectivity of the GC/MS-SIM technique enables the measurement of DNA base products even in isolated mammalian chromatin without the necessity of first isolating DNA, and despite the presence of histones. Recent results reviewed in this article demonstrate the usefulness of the GC/MS technique for chemical determination of free radical-induced DNA damage in DNA as well as in mammalian chromatin under a vast variety of conditions of free radical production. RP DIZDAROGLU, M (reprint author), NATL INST STAND TECHNOL,CTR CHEM TECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 432 Z9 444 U1 1 U2 18 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0891-5849 J9 FREE RADICAL BIO MED JI Free Radic. Biol. Med. PY 1991 VL 10 IS 3-4 BP 225 EP 242 DI 10.1016/0891-5849(91)90080-M PG 18 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA FD464 UT WOS:A1991FD46400010 PM 1650738 ER PT J AU KARAM, LR BERGTOLD, DS SIMIC, MG AF KARAM, LR BERGTOLD, DS SIMIC, MG TI BIOMARKERS OF OH RADICAL DAMAGE INVIVO SO FREE RADICAL RESEARCH COMMUNICATIONS LA English DT Article; Proceedings Paper CT 5TH INTERNATIONAL CONF ON SUPEROXIDE AND SUPEROXIDE DISMUTASE CY SEP 17-22, 1989 CL JERUSALEM, ISRAEL DE HYDROXY RADICAL; ORTHO-TYROSINE; PHENYLALANINE; THYMIDINE GLYCOL; THYMINE ID L-PHENYLALANINE; ORTHO-TYROSINE; META-TYROSINE; PEPTIDES; RATS RP KARAM, LR (reprint author), NATL INST STAND & TECHNOL,CTR RADIAT RES,GAITHERSBURG,MD 20899, USA. NR 24 TC 46 Z9 46 U1 0 U2 2 PU HARWOOD ACAD PUBL GMBH PI READING PA C/O STBS LTD, PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 8755-0199 J9 FREE RADICAL RES COM JI Free Radic. Res. Commun. PY 1991 VL 12-3 BP 11 EP 16 DI 10.3109/10715769109145762 PN 1 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA FK861 UT WOS:A1991FK86100003 PM 1649078 ER PT J AU RHODERICK, GC AF RHODERICK, GC TI DEVELOPMENT OF A GAS STANDARD REFERENCE MATERIAL CONTAINING 18 VOLATILE ORGANIC-COMPOUNDS SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article AB A procedure to prepare primary gas cylinder standards for eighteen volatile organic compounds (VOC's) at the 1 - 15 nmol/mol (ppb) level was developed. The gas standards that were prepared by this procedure were intercompared by using gas chromatography with flame ionization detection (GC-FID) and electron capture detection (GC-ECD). The data, gravimetric concentration of the standards versus the respective GC peak area response, were plotted for each compound and fitted using linear regression. The regression analysis showed excellent agreement among the standards for each compound. These gas standards were evaluated over a period of 2 years and were determined to be stable and accurate. This research resulted in the development of Standard Reference Material (SRM) 1804, which contains these 18 volatile organic compounds in nitrogen at a nominal concentration of 5 nmol/mol for each compound. A batch of cylinders containing the mixture was procured from a commercial supplier. Each cylinder in the batch was analyzed for each of the 18 components. The data showed that the batch was homogeneous and stable for 15 of the 18 organic compounds, resulting in certification and issuance of SRM 1804. RP RHODERICK, GC (reprint author), NATL INST STAND & TECHNOL,CTR ANALYT CHEM,DIV GAS & PARTICULATE SCI,GAS METROL RES GRP,GAITHERSBURG,MD 20899, USA. NR 8 TC 12 Z9 12 U1 1 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0937-0633 J9 FRESEN J ANAL CHEM JI Fresenius J. Anal. Chem. PY 1991 VL 341 IS 9 BP 524 EP 531 DI 10.1007/BF00328489 PG 8 WC Chemistry, Analytical SC Chemistry GA GN737 UT WOS:A1991GN73700004 ER PT J AU KATYUSHINA, VV KRASINETS, MV NUSINOV, AA BART, CA ROTTMAN, GJ AF KATYUSHINA, VV KRASINETS, MV NUSINOV, AA BART, CA ROTTMAN, GJ TI A 2-COMPONENT MODEL OF VARIATION OF THE L-ALPHA-EMISSION DEPENDING ON THE SOLAR-ACTIVITY LEVEL SO GEOMAGNETIZM I AERONOMIYA LA Russian DT Article ID IRRADIANCE VARIATIONS; LYMAN-ALPHA; VARIABILITY; FLUX C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. RP KATYUSHINA, VV (reprint author), HYDROMETEOROL COMM RUSSIA,INST APPL GEOPHYS,MOSCOW,RUSSIA. NR 15 TC 2 Z9 2 U1 0 U2 1 PU MEZHDUNARODNAYA KNIGA PI MOSCOW PA 39 DIMITROVA UL., 113095 MOSCOW, RUSSIA SN 0016-7940 J9 GEOMAGN AERON+ JI Geomagn. Aeron. PD JAN-FEB PY 1991 VL 31 IS 1 BP 40 EP 45 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA FN905 UT WOS:A1991FN90500006 ER PT J AU ZHANG, ZY LIU, RH HUIE, RE KURYLO, MJ AF ZHANG, ZY LIU, RH HUIE, RE KURYLO, MJ TI RATE CONSTANTS FOR THE GAS-PHASE REACTIONS OF THE OH RADICAL WITH CF3CF2CHCL2 (HCFC-225CA) AND CF2CLCF2CHCLF (HCFC-225CB) SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HYDROXYL RADICALS AB Rate constants have been measured for the gas phase reactions of the hydroxyl radical (OH) with the hydrochlorofluorocarbons CF3CF2CHCl2 (HCFC-225ca) over the temperature range 270 to 400 K and CF2ClCF2CHClF (HCFC-225cb) over the temperature range 298 to 400 K. The Arrhenius expressions k(225ca) = (1.92 +/- 0.52) x 10(-12) exp(-1290 +/- 90/T) cm3 molecule-1 s-1 and k(225cb) = (6.75 +/- 3.70) x 10(-13) exp(-1300 +/- 180/T) cm3 molecule-1 s-1 were derived from the kinetic data. RP ZHANG, ZY (reprint author), NATL INST STAND & TECHNOL,DIV CHEM KINET,GAITHERSBURG,MD 20899, USA. RI Huie, Robert/A-5645-2010; Kurylo, Michael/H-2201-2012 NR 10 TC 11 Z9 11 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN PY 1991 VL 18 IS 1 BP 5 EP 7 DI 10.1029/90GL02647 PG 3 WC Geosciences, Multidisciplinary SC Geology GA EV010 UT WOS:A1991EV01000002 ER PT J AU MLYNCZAK, MG SOLOMON, S AF MLYNCZAK, MG SOLOMON, S TI MIDDLE ATMOSPHERE HEATING BY EXOTHERMIC CHEMICAL-REACTIONS INVOLVING ODD-HYDROGEN SPECIES SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LOWER THERMOSPHERE; MODEL; MESOSPHERE; DYNAMICS; HYDROXYL AB We calculate the rate of heating that occurs in the middle atmosphere (50 - 105 km) due to four exothermic reactions involving members of the odd-hydrogen family. These reactions are O + OH --> O2 + H, H + O2 + M --> HO2 + M, H + O3 --> OH + O2, and O + HO2 --> OH + O2. The energy lost from vibrationally excited OH (produced in the third reaction) by spontaneous emission is explicitly accounted for by using detailed kinetic models, so that only a portion of the exothermicity of this reaction is converted into heat. The heating rates due to these four reactions are found to rival the oxygen-related heating rates conventionally considered in models of the middle atmosphere, e.g., those due to O + O + M --> O2 + M, O + O2 + M --> O3 + M, O2 + hv --> O + O, and O3 + hv --> O + O2. The conversion of chemical potential energy into molecular translational energy (heat) by these odd-hydrogen reactions is a significant source of energy in the middle atmosphere which has not been previously considered. C1 NOAA,AERON LAB,BOULDER,CO 80303. RP MLYNCZAK, MG (reprint author), NASA,LANGLEY RES CTR,MAIL STOP 401B,HAMPTON,VA 23665, USA. RI Mlynczak, Martin/K-3396-2012 NR 15 TC 69 Z9 69 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN PY 1991 VL 18 IS 1 BP 37 EP 40 DI 10.1029/90GL02672 PG 4 WC Geosciences, Multidisciplinary SC Geology GA EV010 UT WOS:A1991EV01000010 ER PT B AU STANSBY, M AF STANSBY, M BE SIMOPOULOS, AP KIFER, RR MARTIN, RE BARLOW, SM TI CLINICAL-TESTS - COMMENTS SO HEALTH EFFECTS OF OMEGA3 POLYUNSATURATED FATTY ACIDS IN SEAFOODS SE WORLD REVIEW OF NUTRITION AND DIETETICS LA English DT Proceedings Paper CT 2ND INTERNATIONAL CONF ON THE HEALTH EFFECTS OF OMEGA3 POLYUNSATURATED FATTY ACIDS IN SEAFOOD CY MAR 20-23, 1990 CL WASHINGTON, DC SP US DEPT COMMERCE, NATL OCEAN & ATMOSPER ADM, NATL MARINE FISHERIES SERV, AMER ASSOC WORLD HLTH, CTR GENET NUTRIT & HLTH, INT ASSOC FISH MEAL MANUFACTURERS, NATL FISHERIES INST, US FDA, NCI, NIAAA, NIH, NIAMSD, NICHHD RP STANSBY, M (reprint author), NATL MARINE FISHERIES SERV,NW & ALASKA FISHERIES RES INST,SEATTLE,WA, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KARGER PI BASEL PA BASEL BN 3-8055-5244-0 J9 WORLD REV NUTR DIET JI World Rev.Nutr.Diet. PY 1991 VL 66 BP 12 EP 14 PG 3 WC Biochemistry & Molecular Biology; Nutrition & Dietetics SC Biochemistry & Molecular Biology; Nutrition & Dietetics GA BS88U UT WOS:A1991BS88U00003 PM 2053333 ER PT J AU BOECKER, B HALL, R INN, K LAWRENCE, J ZIEMER, P EISELE, G WACHHOLZ, B BURR, W AF BOECKER, B HALL, R INN, K LAWRENCE, J ZIEMER, P EISELE, G WACHHOLZ, B BURR, W TI CURRENT STATUS OF BIOASSAY PROCEDURES TO DETECT AND QUANTIFY PREVIOUS EXPOSURES TO RADIOACTIVE MATERIALS SO HEALTH PHYSICS LA English DT Article ID MASS-SPECTROMETRY; FALLOUT PLUTONIUM; URINARY-EXCRETION; AUTOPSY TISSUE; SOUTHERN FINNS; SYSTEMIC PU; VARIABILITY; IONIZATION AB This report was prepared by a working group established by the Oak Ridge Associated Universities (ORAU) for the purpose of assessing the current capabilities of bioassay methods that can be used to determine the occurrence and magnitude of a previous internal deposition of one or more radionuclides. The first five sections discuss general features of the use of in-vitro bioassay samples to achieve this purpose. The remainder of the report is focused on the possible use of urine bioassay procedures to detect and quantify internal depositions of radionuclides that may have occurred in United States occupation troops in Hiroshima or Nagasaki, Japan, prior to 1 July 1946, or to personnel who participated in atmospheric nuclear weapons tests conducted between 1945 and 1962. Theoretical calculations were made to estimate the quantities of various radionuclides produced in a 20-kiloton (kt) nuclear detonation that might still be present in measurable quantities in people today if they were exposed 25 to 40 y ago. Two radionuclides that emerged as good choices for this type of bioassay analysis were Sr-90, which emits beta particles, and Pu-239, Pu-240, which emits alpha particles. The current status and future prospects of chemical procedures for analyzing in-vitro urine bioassay samples for these two radionuclides were examined to determine the minimum amounts that could be detected with current methods and how much one might expect the sensitivity of detection to improve in the near future. Most routine Pu-239, Pu-240 bioassay analyses involve detection by alpha spectrometry. The current minimum detectable amount (MDA) is about 0.74 mBq L-1 (20 fCi L-1), but this could be lowered to 74-mu-Bq L-1 (2 fCi L-1). An MDA of 0.74 mBq L-1 (20 fCi L-1) is adequate for routine bioassay analyses but is too high to detect most uptakes of Pu-239, Pu-240 that may have occurred 25 to 40 y ago. Methods under development that are or can be much more sensitive and have lower MDAs than alpha spectrometry for Pu-239 are fission track analysis and mass spectrometry. Currently, the fission track analysis method has an MDA of about 19-mu-Bq L-1 (0.5 fCi L-1), and this may eventually be lowered to 1.9-mu-Bq L-1 (0.05 fCi L-1). The current MDA for Pu-239 by mass spectrometry is about 7.4 mBq L-1 (200 fCi L-1), but the potential exists that it could be lowered to a value of about 0.37-mu-Bq L-1 (0.01 fCi L-1). For Sr-90, low-background beta counting is one of the best methods currently available. Mass spectrometry could also be used if desired. The current minimum detectable amount, MDA, for Sr-90 in a urine sample using low-background beta counting is about 7.4 mBq L-1 (200 fCi L-1) of urine. This MDA could be reduced to about 1.1 mBq L-1 (30 fCi L-1) if needed. Bioassay measurements provide only an indirect measurement of how much of a particular radionuclide is present in the body at the time of sampling. Mathematical models are used to estimate the currently retained body burden, the initial body burden when uptake occurred, and the cumulative dose equivalents received by various body organs and tissues. Models of these types for Sr-90 and Pu-39, Pu-240 have received much scientific attention over the past 40 y, and the models available for use today appear to be reasonable for interpretation of bioassay results for intakes that may have occurred 25 to 40 y ago. One of the major problems that is encountered when interpreting a particular Sr-90 or Pu-239, Pu-240 bioassay result is that, because of worldwide fallout from past atmospheric detonations, everyone contains some Sr-90 and Pu-239, Pu-240. The amount of background Sr-90 or Pu-239, Pu-240 in people is quite variable and depends on a number of factors including age, diet, and geographical location. The accuracy of bioassay for detecting a previous exposure to Sr-90 or Pu-239, Pu-240 in an individual depends, among other things, on how well the expected background level for Sr-90 or Pu-239, Pu-240 in an individual can be estimated and subtracted from the total amount present to determine whether excess Sr-90 or Pu-239, Pu-240 is present. Exposure to other radionuclides from occupational, medical, or natural background sources can also interfere with a bioassay analysis, but they can be accounted for more easily than can background levels of Sr-90 or Pu-239, Pu-240. Propagation of uncertainty values that may be representative of those encountered in an actual bioassay program indicate that the uncertainty of the dose estimated from a bioassay sample is such that the 5th and 95th percentiles can be at least four to seven times smaller or larger, respectively, than the geometric mean values. A possible strategy for implementing such a biossay program is suggested in this report. It is based on the concept of testing the usefulness of bioassay in relatively small groups of military personnel who, by virtue of their location and/or activities, may have had the highest likelihood of an internal deposition. These could be selected from situations involving exposure to descending fallout or radionuclides resuspended from various surfaces. In addition to selection of individuals based on their location or activities, individuals with high film-badge readings could also be sampled. If these efforts indicate that urine bioassay can, in fact, provide useful information on past exposures, other groups can also be sampled. When no excess Sr-90 or Pu-239, Pu-240 is detected, it is then possible to place an upper bound on the internal deposition and associated radiation dose that may have been recieved but not detected. Improving sensitivity of the analytical methods available can substantially reduce the magnitude of such undetected uptakes and radiation doses, especially for Pu-239, Pu-240. C1 DUPONT CO, SAVANNAH RIVER LAB, AIKEN, SC 29801 USA. NBS, CTR RADIAT RES, GAITHERSBURG, MD 20899 USA. UNIV CALIF LOS ALAMOS SCI LAB, LOS ALAMOS, NM 87545 USA. PURDUE UNIV, SCH HLTH SCI, W LAFAYETTE, IN 47907 USA. OAK RIDGE ASSOCIATED UNIV, OAK RIDGE, TN 37831 USA. NCI, BETHESDA, MD 20892 USA. RP BOECKER, B (reprint author), LOVELACE INHALAT TOXICOL RES INST, POB 5890, ALBUQUERQUE, NM 87185 USA. NR 99 TC 42 Z9 42 U1 0 U2 1 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. PY 1991 VL 60 SU 1 BP 45 EP 100 PG 56 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 FE834 UT WOS:A1991FE83400004 PM 2004918 ER PT J AU SCHMUTZ, W KOENINGSBERGER, G UNDERHILL, AB OWOCKI, SP SCHULTELADBECK, RE POLLOCK, AMT AF SCHMUTZ, W KOENINGSBERGER, G UNDERHILL, AB OWOCKI, SP SCHULTELADBECK, RE POLLOCK, AMT TI OBSERVATIONS VERSUS ATMOSPHERIC MODELS OF WR STARS SO IAU SYMPOSIA LA English DT Article ID WOLF-RAYET STARS; LARGE MAGELLANIC CLOUD; FE-V; OPTICAL SPECTROPHOTOMETRY; ULTRAVIOLET-SPECTRUM; IUE OBSERVATIONS; EMISSION-LINES; HOT STARS; WN STARS; WC STARS AB Current knowledge of Wolf-Rayet continua is reviewed and observed continuum energy distributions are compared with model predictions. Good agreement is found. For WN stars a large range in intrinsic color is found for each subclass and the so far unexplained large range in the observed reddening-free continuum indices can be understood on the basis of atmospheric models. The strength of the continuum discontinuities determines the value of the index. Because of severe blending by the emission lines in WC spectra it can not be decided whether the intrinsic colors of WC stars of a given spectral type vary over a range of values or whether all stars of a given spectral type are similar. The reliability of model calculations for Wolf-Rayet stars is further tested by comparing observed and predicted correlations of helium line strengths. Satisfactory agreement is found for the Kiel/JILA models but not for the Bhatia-Underhill models. Methods used to determine the reddening due to interstellar extinction are reviewed and their accuracies estimated. C1 NATL AUTONOMOUS UNIV MEXICO,INST ASTRON,MEXICO CITY 04510,DF,MEXICO. UNIV BRITISH COLUMBIA,DEPT GEOPHYS & ASTRON,VANCOUVER V6T 1W5,BC,CANADA. UNIV DELAWARE,BARTOL RES INST,NEWARK,DE 19716. UNIV WISCONSIN,SPACE ASTRON LAB,MADISON,WI 53706. COMP & SCI CO LTD,SHEFFIELD S11 7EY,ENGLAND. RP SCHMUTZ, W (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Schmutz, Werner/B-4153-2014 OI Schmutz, Werner/0000-0003-1159-5639 NR 44 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 0074-1809 J9 IAU SYMP PY 1991 IS 143 BP 39 EP 52 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HK279 UT WOS:A1991HK27900004 ER PT J AU HILLIER, DJ POLLOCK, AMT UNDERHILL, AB LANGER, N AF HILLIER, DJ POLLOCK, AMT UNDERHILL, AB LANGER, N TI THEORY OF WOLF-RAYET ATMOSPHERES SO IAU SYMPOSIA LA English DT Article ID HE-II SPECTRA; WC STARS; ELECTRON-SCATTERING; IUE OBSERVATIONS; MASSIVE STARS; HOT STARS; WN STARS; HD-50896; ABUNDANCES; EVOLUTION AB Theoretical modeling of line and continuum formation in Wolf-Rayet (W-R) atmospheres is reviewed. We examine the basic premises on which the models are built, and critically compare theoretical models with observation. Discrepancies between theory and observation are analyzed to determine their implication for our understanding of W-R atmospheres. Line formation, continuum formation, and the ionization structure of W-R envelopes are examined in detail. Abundance determinations are briefly reviewed. C1 COMP & SCI CO LTD,SHEFFIELD S11 7EY,ENGLAND. UNIV BRITISH COLUMBIA,DEPT GEOPHYS & ASTRON,VANCOUVER V6T 1W5,BC,CANADA. UNIV GOTTINGEN,W-3400 GOTTINGEN,GERMANY. RP HILLIER, DJ (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 57 TC 2 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1991 IS 143 BP 59 EP 73 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HK279 UT WOS:A1991HK27900006 ER PT J AU NIEMELA, VS KOENIGSBERGER, G CONTI, PS SCHMUTZ, W MASSEY, PL AF NIEMELA, VS KOENIGSBERGER, G CONTI, PS SCHMUTZ, W MASSEY, PL TI NEW WOLF-RAYET BINARIES SO IAU SYMPOSIA LA English DT Article ID LARGE MAGELLANIC CLOUD; STARS AB Preliminary radial velocity orbits are presented for three binary systems containing Wolf-Rayet stars, namely Sk-71-degrees 34 in the LMC, and WR8 and WR98 in our galaxy. Sk-71-degrees 34 is found to be a WN3 + O6 double-lined binary with an elliptic orbit of period about 34 days. WR8 and WR98 both have WN type spectra with carbon lines. In WR8 the N and C lines appear to move in antiphase, while in WR98 all emission lines have the same orbital motion. C1 INST ASTRON & FIS ESPACIO,RA-1428 BUENOS AIRES,ARGENTINA. NATL AUTONOMOUS UNIV MEXICO,INST ASTRON,MEXICO CITY 04510,DF,MEXICO. UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. KITT PEAK NATL OBSERV,TUCSON,AZ 85726. NR 4 TC 2 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1991 IS 143 BP 201 EP 206 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HK279 UT WOS:A1991HK27900018 ER PT J AU DEGREVE, JP CONTI, PS CHEREPASHCHUK, AM VANBEVEREN, D UNDERHILL, AB MAEDER, A SCHULTELADBECK, RE SMITH, L MOFFAT, AFJ AF DEGREVE, JP CONTI, PS CHEREPASHCHUK, AM VANBEVEREN, D UNDERHILL, AB MAEDER, A SCHULTELADBECK, RE SMITH, L MOFFAT, AFJ TI WR BINARIES - THEORETICAL ASPECTS SO IAU SYMPOSIA LA English DT Article ID WOLF-RAYET STARS; MASSIVE CLOSE BINARIES; LOSS RATES; EVOLUTION; DIAGRAM AB The different channels for the formation of WR-stars, as suggested in the literature, are investigated. The presently available tools, in terms of evolutionary recipies, are reviewed and the results investigated of the use of these tools, with respect to the WR-binaries. Two of the three basic formation channels, mentioned in the literature, may serve as ways to obtain the presently observed group of WR-binaries: stellar wind mass loss in O-stars during the pre-WR phase and mass transfer in a massive close binary system. Discrepancies with observations necessitated the incorporation of stellar wind in the binary scenario. Theoretical developments in the last years are reviewed and confronted with the observations. The necessity of mass transfer in the formation process is argued for a major fraction of the double-lined WR-binaries. Using specific evolutionary ingredients, the original parameters of the systems are calculated. We also discuss the appearance and disappearance of double-lined WR-systems as well as the existence of eccentric WR-systems after mass transfer. The evolution of a number of specific systems is discussed individually. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. MV LOMONOSOV STATE UNIV,STERNBERG ASTRON INST,MOSCOW 117234,USSR. VRIJE UNIV BRUSSELS,INST FYS,B-1050 BRUSSELS,BELGIUM. UNIV BRITISH COLUMBIA,DEPT GEOPHYS & ASTRON,VANCOUVER V6T 1W5,BC,CANADA. OBSERV GENEVA,CH-1290 SAUVERNY,SWITZERLAND. UNIV WISCONSIN,SPACE ASTRON LAB,MADISON,WI 53706. UNIV MONTREAL,DEPT PHYS,MONTREAL H3C 3J7,QUEBEC,CANADA. RP DEGREVE, JP (reprint author), VRIJE UNIV BRUSSELS,INST ASTROPHYS,PLEINLAAN 2,B-1050 BRUSSELS,BELGIUM. NR 47 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1991 IS 143 BP 213 EP 228 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HK279 UT WOS:A1991HK27900020 ER PT J AU VILCHEZ, JM ESTEBAN, C SCHMUTZ VANDERHUCHT AF VILCHEZ, JM ESTEBAN, C SCHMUTZ VANDERHUCHT TI ABUNDANCES IN WR NEBULAE SO IAU SYMPOSIA LA English DT Article ID RING NEBULAE; STARS AB Within an ongoing program of long slit spectroscopy of the known WR nebulae, we show here some results for eight objects of the sample selected from the master list of Chu et al. (1983). We present an analysis of their ionisation structure and determine abundances of oxygen, nitrogen and helium in as many positions as possible. The implications of the abundance results for the chemical enrichment of the Interstellar Medium and stellar nucleosynthesis are briefly reviewed. C1 UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302. SRON SPACE RES UTRECHT,UTRECHT,NETHERLANDS. RP VILCHEZ, JM (reprint author), INST ASTROFIS CANARIAS,E-38200 LA LAGUNA,SPAIN. NR 13 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 1991 IS 143 BP 379 EP 384 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA HK279 UT WOS:A1991HK27900034 ER PT J AU ROCKEN, C JOHNSON, JM NEILAN, RE CEREZO, M JORDAN, JR FALLS, MJ NELSON, LD WARE, RH HAYES, M AF ROCKEN, C JOHNSON, JM NEILAN, RE CEREZO, M JORDAN, JR FALLS, MJ NELSON, LD WARE, RH HAYES, M TI THE MEASUREMENT OF ATMOSPHERIC WATER-VAPOR - RADIOMETER COMPARISON AND SPATIAL VARIATIONS SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID GLOBAL POSITIONING SYSTEM; BASELINE; INTERFEROMETRY; LENGTH; DELAY AB We conducted two water vapor radiometer (WVR) experiments to evaluate whether such instruments are both suitable and needed to correct for propagation effects that are induced by precipitable water vapor (PWV) on signals from the Global Positioning System (GPS) and Very Long Baseline Interferometry (VLBI). WVR's are suitable for these corrections if they provide wet path delays to better than 0.5 cm. They are needed if spatial variations of PWV result in complicated, direction-dependent propagation effects that are too complex to be parametrized in the GPS or VLBI geodetic solution. In the first experiment we addressed the suitability of radiometers by comparing six WVR's at Stapleton International Airport in Denver, Colorado, for two weeks. While two WVR's showed an average wet path delay bias of only 0.1 cm, others were biased by 1-3 cm relative to each other and relative to radiosondes. The second experiment addressed the question whether radiometers are needed for the detection of inhomogeneities in the wet delay. Three JPL D-series radiometers were operated at three sites in Colorado approximately 50-km apart. The WVR's simultaneously sampled PWV at different azimuths and elevations in search of spatial variations of PWV. On one day of this second experiment we found evidence for spatial variations of the wet path delay as high as 20% of the total wet path delay. C1 UNIV COLORADO,COLORADO CTR ASTRODYNAM RES,BOULDER,CO 80309. CALTECH,JET PROP LAB,PASADENA,CA 91109. NOAA,ENVIRONM RES LABS,BOULDER,CO 80303. RADIOMETR CORP,BOULDER,CO 80301. NASA,GODDARD SPACE FLIGHT CTR,INTERFEROMETR INC,GREENBELT,MD 20771. RP ROCKEN, C (reprint author), UNIV COLORADO,UNIV NAVSTAR CONSORTIUM,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309, USA. NR 24 TC 21 Z9 21 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 1991 VL 29 IS 1 BP 3 EP 8 DI 10.1109/36.103286 PG 6 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA ER649 UT WOS:A1991ER64900001 ER PT J AU KRUSE, FA HAUFF, PL AF KRUSE, FA HAUFF, PL TI IDENTIFICATION OF ILLITE POLYTYPE ZONING IN DISSEMINATED GOLD DEPOSITS USING REFLECTANCE SPECTROSCOPY AND X-RAY-DIFFRACTION - POTENTIAL FOR MAPPING WITH IMAGING SPECTROMETERS SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID NEVADA; MINE AB X-ray diffraction studies of clay minerals from disseminated gold deposits in Nevada demonstrate that illite polytypes are often laterally and vertically zoned around ore bodies. Polytypes act as geothermometers indicating temperatures of ore deposition and thus proximity to the hydrothermal fluids during deposition. Visible/infrared reflectance spectroscopy for field identification and mapping of the illite polytypes is evaluated. Laboratory spectral measurements demonstrate that systematic changes occur as the illites progress from the lower temperature, less ordered 1M variety through the higher temperature 2M type. Distinctive absorption features near 1.90 and 2.20-mu-m and between 2.3-2.5-mu-m differentiate interlayer water, structural water (OH-), and some octahedral layer characteristics. These changes were also observed in the laboratory using a field portable spectrometer and in situ at a major disseminated gold deposit. The results demonstrate that reflectance spectroscopy can be used to assist gold exploration efforts by providing detailed mineralogical information in real time at the field location. As the new generation of imaging spectrometers is developed, it is likely that subtle spectral differences such as those between the illite polytypes will become useful for remote exploration for gold deposits. RP KRUSE, FA (reprint author), UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,CTR STUDY EARTH SPACE,BOULDER,CO 80309, USA. NR 20 TC 11 Z9 14 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 1991 VL 29 IS 1 BP 101 EP 104 DI 10.1109/36.103298 PG 4 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA ER649 UT WOS:A1991ER64900013 ER PT J AU CAYULA, JF CORNILLON, P HOLYER, R PECKINPAUGH, S AF CAYULA, JF CORNILLON, P HOLYER, R PECKINPAUGH, S TI COMPARATIVE-STUDY OF 2 RECENT EDGE-DETECTION ALGORITHMS DESIGNED TO PROCESS SEA-SURFACE TEMPERATURE-FIELDS SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Note AB Two algorithms used for the detection of fronts in satellite-derived sea-surface temperature fields are compared and shown to give similarly good results. The main differences are that the algorithm based on a multilevel approach is faster and that it automatically adapts to process a wide range of SST images and regions within these images. C1 NOAA,DEPT NAVY,COMP SCI SECT,STENNIS SPACE CTR,MS 39529. RP CAYULA, JF (reprint author), UNIV RHODE ISL,GRAD SCH OCEANOG,NARRAGANSETT,RI 02882, USA. NR 3 TC 11 Z9 12 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 1991 VL 29 IS 1 BP 175 EP 177 DI 10.1109/36.103308 PG 3 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA ER649 UT WOS:A1991ER64900023 ER PT J AU HARMAN, D MCCOY, W TOENSE, R CANDELA, G AF HARMAN, D MCCOY, W TOENSE, R CANDELA, G TI PROTOTYPING A DISTRIBUTED INFORMATION-RETRIEVAL SYSTEM THAT USES STATISTICAL RANKING SO INFORMATION PROCESSING & MANAGEMENT LA English DT Article ID STRATEGIES; TEXT AB Centralized systems continue to dominate the information retrieval market, with increased competition from CD-ROM based systems. As more large organizations begin to implement office automation systems, however, many will find that neither of these types of retrieval systems will satisfy their requirements, especially those requirements involving easy integration into other systems and heavy usage by casual end users. A prototype distributed information retrieval system was designed and built using a distributed architecture and using statistical ranking techniques to help provide better service for the end user. The distributed architecture was shown to be a feasible alternative to centralized or CD-ROM information retrieval, and user testing of the ranking methodology showed both widespread user enthusiasm for this retrieval technique and very fast response times (on the order of one second for 300 megabytes of data). RP NIST, GAITHERSBURG, MD 20899 USA. NR 23 TC 7 Z9 7 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0306-4573 EI 1873-5371 J9 INFORM PROCESS MANAG JI Inf. Process. Manage. PY 1991 VL 27 IS 5 BP 449 EP 460 DI 10.1016/0306-4573(91)90062-Q PG 12 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA GF368 UT WOS:A1991GF36800003 ER PT J AU SALOMAN, EB AF SALOMAN, EB TI THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY RESONANCE IONIZATION SPECTROSCOPY RESONANCE IONIZATION MASS-SPECTROMETRY DATA SERVICE SO INSTITUTE OF PHYSICS CONFERENCE SERIES LA English DT Article AB A resonance ionization spectroscopy data service has been established at the National Institute of Standards and Technology. It publishes formatted data sheets which provide the atomic and laser physics information to apply RIS/RIMS to a given element. A first group of ten data sheets has been published. It covers As, B, Cd, C, Ge, Au, Fe, Pb, Si, and Zn. A second group has been submitted for publication. It covers Al, Ca, Cs, Cr, Co, Cu, Kr, Mg, Hg, and Ni. More will be produced in the future. RP NATL INST STAND & TECHNOL, DIV ELECTRON & OPT PHYS, GAITHERSBURG, MD 20899 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0951-3248 J9 INST PHYS CONF SER JI Inst. Phys. Conf. Ser. PY 1991 IS 114 BP 45 EP 48 PG 4 WC Physics, Multidisciplinary SC Physics GA FW899 UT WOS:A1991FW89900011 ER PT J AU LI, Q MCILRATH, TJ SALOMAN, EB LUCATORTO, TB AF LI, Q MCILRATH, TJ SALOMAN, EB LUCATORTO, TB TI RIS STUDIES OF AUTOIONIZATION IN CALCIUM SO INSTITUTE OF PHYSICS CONFERENCE SERIES LA English DT Article AB Autoionizing levels belonging to configurations of 3p6 3dnl are being studied as part of an effort to find efficient ionization pathways applicable to ultrasensitive isotopic analysis and laser isotope separation. The studies are performed in a RIMS apparatus with a time-of-flight mass spectrometer and simple thermal filament atomization source. Estimates of two-photon transition rates and excited state photoionization cross sections show that the 4s2 1S0--> -->3d5s 1D2-->3d7p 1P1 (autoionizing) ionization pathway might be efficient enough to allow effective isotopically selective ionization with cw Ti: sapphire lasers. C1 UNIV MARYLAND,IPST,COLLEGE PK,MD 20742. RP LI, Q (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 9 TC 2 Z9 2 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0951-3248 J9 INST PHYS CONF SER JI Inst. Phys. Conf. Ser. PY 1991 IS 114 BP 55 EP 58 PG 4 WC Physics, Multidisciplinary SC Physics GA FW899 UT WOS:A1991FW89900013 ER PT J AU PERUGINI, NE WADDINGTON, TR NOLL, GT AF PERUGINI, NE WADDINGTON, TR NOLL, GT TI IMPLEMENTATION OF THE HYDROGRAPHIC DATA ACQUISITION AND PROCESSING SYSTEM (HDAPS) IN THE NOAA FLEET SO INTERNATIONAL HYDROGRAPHIC REVIEW LA English DT Article AB The U.S. National Oceanic and Atmospheric Administration (NOAA) has developed an automated system for acquiring and processing hydrographic field data in support of its charting mission. The Hydrographic Data Acquisition and Processing System (HDAPS) addresses NOAA's broad requirement to conduct hydrographic surveys in the coastal waters of the U.S. Systems have been successfully deployed on ships, launches, and small boats. Two types of HDAPS data acquisition systems (DAS) are presented. The first system, based on Hewlett-Packard (HP) hardware, is deployed on ships and launches. The second type is a small boat, 24-volt system, based on IBM-PC compatible hardware. Both types of DAS are capable of conducting echo sounding and side scan sonar surveys. Data acquired by both systems are processed on an HP-based data processing system. RP PERUGINI, NE (reprint author), NOAA,HYDROG SURVEYS BRANCH,ROCKVILLE,MD 20852, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT HYDROGRAPHIC BUREAU PI MONTE CARLO PA AVE PRES J F KENNEDY, MONTE CARLO, MONACO SN 0020-6946 J9 INT HYDROGR REV JI Int. Hydrogr. Rev. PD JAN PY 1991 VL 68 IS 1 BP 127 EP 139 PG 13 WC Engineering, Marine; Oceanography; Water Resources SC Engineering; Oceanography; Water Resources GA EW593 UT WOS:A1991EW59300009 ER PT J AU HASTINGS, DA CLARK, DM AF HASTINGS, DA CLARK, DM TI GIS IN AFRICA - PROBLEMS, CHALLENGES AND OPPORTUNITIES FOR COOPERATION SO INTERNATIONAL JOURNAL OF GEOGRAPHICAL INFORMATION SYSTEMS LA English DT Article RP HASTINGS, DA (reprint author), NOAA,NATL GEOPHYS DATA CTR,325 BROADWAY,BOULDER,CO 80303, USA. NR 7 TC 17 Z9 17 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0269-3798 J9 INT J GEOGR INF SYST JI Int. J. Geogr. Inf. Syst. PD JAN-MAR PY 1991 VL 5 IS 1 BP 29 EP 39 DI 10.1080/02693799108927829 PG 11 WC Geography; Information Science & Library Science SC Geography; Information Science & Library Science GA FK051 UT WOS:A1991FK05100004 ER PT J AU HASTINGS, DA KINEMAN, JJ CLARK, DM AF HASTINGS, DA KINEMAN, JJ CLARK, DM TI DEVELOPMENT AND APPLICATION OF GLOBAL DATABASES - CONSIDERABLE PROGRESS, BUT MORE COLLABORATION NEEDED SO INTERNATIONAL JOURNAL OF GEOGRAPHICAL INFORMATION SYSTEMS LA English DT Article RP HASTINGS, DA (reprint author), NOAA,NATL GEOPHYS DATA CTR,325 BROADWAY,BOULDER,CO 80303, USA. NR 13 TC 6 Z9 6 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0269-3798 J9 INT J GEOGR INF SYST JI Int. J. Geogr. Inf. Syst. PD JAN-MAR PY 1991 VL 5 IS 1 BP 137 EP 146 DI 10.1080/02693799108927837 PG 10 WC Geography; Information Science & Library Science SC Geography; Information Science & Library Science GA FK051 UT WOS:A1991FK05100012 ER PT J AU BOUDEN, M DATTA, SK SHAH, AH AF BOUDEN, M DATTA, SK SHAH, AH TI DYNAMIC-RESPONSE OF A LAYERED HALF-SPACE WITH INTERFACIAL CRACKS SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article ID ELASTIC WAVE SCATTERING; DIFFRACTION; TRACTIONS; WATER AB The scattering of elastic waves by interfacial cracks in a layered medium is investigated in this paper. A hybrid numerical method is employed to obtain the solution. This method combines the finite element equations and the Green's function boundary integral representation. Numerical results are presented for the crack-opening displacements (CODs) and the Mode I and Mode II stress-intensity factors (SIFs) as functions of nondimensional frequency when normal and tangential time-harmonic line loads are applied to the free surface of the layered medium. C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV MANITOBA,DEPT CIVIL ENGN,WINNIPEG R3T 2N2,MANITOBA,CANADA. RP BOUDEN, M (reprint author), UNIV COLORADO,DEPT MECH ENGN,BOULDER,CO 80309, USA. NR 24 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PY 1991 VL 28 IS 5 BP 533 EP 548 DI 10.1016/0020-7683(91)90170-K PG 16 WC Mechanics SC Mechanics GA FY826 UT WOS:A1991FY82600001 ER PT J AU JACKSON, CL SHAW, MT AF JACKSON, CL SHAW, MT TI POLYMER LIQUID-CRYSTALLINE MATERIALS SO INTERNATIONAL MATERIALS REVIEWS LA English DT Review ID SIDE-CHAIN POLYMERS; RIGID-ROD POLYMERS; POLY(GAMMA-BENZYL L-GLUTAMATE) SOLUTIONS; PARA-AROMATIC POLYMERS; MAIN-CHAIN; RODLIKE PARTICLES; LIGHT-SCATTERING; STATISTICAL THERMODYNAMICS; THERMOTROPIC POLYESTERS; RHEOLOGICAL PROPERTIES AB A review of the chemical structures, physical properties, and current and potential applications of liquid crystalline polymers (LCPs) is presented. Comparisons are made between LCPs, low molecular weight liquid crystals (LCs), and conventional polymers for readers unfamiliar with the field. The ordered liquid phases are classified and molecular requirements for the formation of LC phases in both LCP melts (thermotropics) and LCP solutions (lyotropics) are discussed. The theoretical predictions of the formation of ordered phases given by Flory and Onsager are compared with experimental data, and other aspects of the phase behaviour of LCPs in solution are considered, including physical gelation and crystal-solvate complexes. A wide variety of polymer structures that exhibit LC behaviour are presented. These include main chain (rigid rod), semiflexible, main chain with flexible spacers, and side chain LCPs, and various new combinations that have been recently devised. An emphasis is placed on the relationship between chemical and physical structure of LCPs, rather than on the details of the synthesis. The unique physical properties of these materials, including the rheological or flow behaviour, optical, electrical, and mechanical properties, and possible applications in blends, composites, optical devices, elastomers, and other areas are highlighted. C1 NATL INST STAND & TECHNOL, GAITHERSBURG, MD USA. UNIV CONNECTICUT, INST MAT SCI, DEPT CHEM ENGN, STORRS, CT 06268 USA. NR 218 TC 11 Z9 11 U1 4 U2 21 PU MANEY PUBLISHING PI LEEDS PA STE 1C, JOSEPHS WELL, HANOVER WALK, LEEDS LS3 1AB, W YORKS, ENGLAND SN 0950-6608 EI 1743-2804 J9 INT MATER REV JI Int. Mater. Rev. PY 1991 VL 36 IS 5 BP 165 EP 186 PG 22 WC Materials Science, Multidisciplinary SC Materials Science GA GN875 UT WOS:A1991GN87500001 ER PT J AU FAHNENSTIEL, GL CARRICK, HJ ROGERS, CE SICKOGOAD, L AF FAHNENSTIEL, GL CARRICK, HJ ROGERS, CE SICKOGOAD, L TI RED FLUORESCING PHOTOTROPHIC PICOPLANKTON IN THE LAURENTIAN GREAT-LAKES - WHAT ARE THEY AND WHAT ARE THEY DOING SO INTERNATIONALE REVUE DER GESAMTEN HYDROBIOLOGIE LA English DT Article DE EPIFLUORESCENCE MICROSCOPY; FLOW CYTOMETRY; TRANSMISSION ELECTRON MICROSCOPY; RED FLUORESCING PHOTOTROPHIC PICOPLANKTON; LAURENTIAN GREAT LAKES ID LAKE-MICHIGAN PHYTOPLANKTON; VERTICAL-DISTRIBUTION; NORTH-ATLANTIC; WATER-QUALITY; COMMUNITIES; HURON; BIOMASS; SIZE; ULTRAPHYTOPLANKTON; AUTORADIOGRAPHY AB Epifluorescence microscopy, flow cytometry, and transmission electron microscopy were used to characterize the community of red fluorescing (emission > 665 nm when excited with blue light) phototrophic picoplankton (RFPP) in lakes Huron and Michigan. A population of coccoid to ovate eukaryotic cells with a mean size of 1.2-mu-m dominated the RFPP community in both surface and deep water samples. Abundant prochlorophyte populations were not found in any samples. Comparisons of counts with epifluorescence microscopy and flow cytometry, revealed that RFPP were adequately enumerated with standard epifluorescence microscopy. These RFPP were significant contributors to total phototrophic picoplankton abundance in both lakes Michigan (24 %) and Huron (18 %), with maximum seasonal abundance during the May-June period (surface mixing layer temperatures, 3-9-degrees-C). During thermal stratification, maximum vertical abundance was found in the metalimnion/hypolimnion at the 1-5 % isolumes. RFPP were only minor contributors (1-7 %) to total primary production. Growth rates of RFPP measured with dilution and small inocula growth experiments ranged from 0.05-1.0 d-1. Microzooplankton grazing rates on RFPP measured with dilution experiments were similar to estimated growth rates, accounting for 52-280 % of growth on any given date. C1 UNIV MICHIGAN,DEPT INTERNAL MED,SIMPSON FLOW CYTOMETRY FACIL,ANN ARBOR,MI 48109. UNIV MICHIGAN,CTR GREAT LAKES & AQUAT SCI,ANN ARBOR,MI 48109. RP FAHNENSTIEL, GL (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 37 TC 32 Z9 34 U1 2 U2 3 PU AKADEMIE VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0020-9309 J9 INT REV GES HYDROBIO JI Int. Rev. Gesamten Hydrobiol. PY 1991 VL 76 IS 4 BP 603 EP 616 DI 10.1002/iroh.19910760411 PG 14 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA HE115 UT WOS:A1991HE11500010 ER PT J AU FAHNENSTIEL, GL PATTON, TR CARRICK, HJ MCCORMICK, MJ AF FAHNENSTIEL, GL PATTON, TR CARRICK, HJ MCCORMICK, MJ TI DIEL DIVISION CYCLE AND GROWTH-RATES OF SYNECHOCOCCUS IN LAKES HURON AND MICHIGAN SO INTERNATIONALE REVUE DER GESAMTEN HYDROBIOLOGIE LA English DT Article DE SYNECHOCOCCUS; DIEL DIVISION PATTERN; FREQUENCY OF DIVIDING CELLS (FDC) METHOD; DURATION OF DIVISION ID MARINE SYNECHOCOCCUS; CELL-DIVISION; PATTERNS; LIGHT; CYANOBACTERIA; PHYTOPLANKTON; PICOPLANKTON; POPULATIONS AB A clone of Synechococcus isolated from Lake Huron and natural populations of Synechococcus from lakes Huron and Michigan were studied in 1989 to examine the diel division cycle and to provide estimates of the in situ growth rate based on the frequency of dividing cells (FDC) method. Cultured populations of Synechococcus exhibited a consistent diel division pattern with a midday/afternoon (1100-1800 h) peak in the percent of dividing cells. The maximum percent of dividing cells varied among cultures (8-27 %) and was related to the growth rate. A small fraction of dividing cells (3-5 %) remained throughout the dark period, suggesting that some cells were arrested in the doublet stage prior to division. The duration of division (t(d)) ranged from 2.6-4.9 h, with a 3.7 h mean for cultures with growth rates greater-than-or-equal-to 0.34 d-1 but increased to 8 h at a lower growth rate of 0.20 d-1. The diel division pattern for natural populations was very similar to the laboratory clone; an afternoon peak (1400-2100 h) in dividing cells and a small fraction of dividing cells (2-5 %) remained during the dark period. The maximum percent of dividing cells for natural populations ranged from 6-10 %. In situ growth rates, determined from the FDC and assuming a constant t(d) of 3.7 h, ranged from 0.30-0.42 d-1. The FDC method may provide accurate estimates of in situ growth, particularly in environments where the growth rate is > 0.34 d-1, but in lakes Huron and Michigan where growth rates can be lower and t(d) values may increase, FDC-growth rates must be viewed with caution. RP FAHNENSTIEL, GL (reprint author), GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 17 TC 10 Z9 10 U1 1 U2 1 PU AKADEMIE VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0020-9309 J9 INT REV GES HYDROBIO JI Int. Rev. Gesamten Hydrobiol. PY 1991 VL 76 IS 4 BP 657 EP 664 DI 10.1002/iroh.19910760415 PG 8 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA HE115 UT WOS:A1991HE11500014 ER PT J AU OSELLA, SA RIDDER, SD BIANCANIELLO, FS ESPINA, PI AF OSELLA, SA RIDDER, SD BIANCANIELLO, FS ESPINA, PI TI THE INTELLIGENT CONTROL OF AN INERT-GAS ATOMIZATION PROCESS SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article AB Intelligent control is an attempt to specify the function of a controller in ways which mimic the decision-making capabilities of humans. Traditionally, issues relating to the emulation of human-like capabilities have fallen in the domain of artificial intelligence. Intelligent processing is a specific form of intelligent control in which the system to be controlled is a process rather than the more conventional mechanical or electrical system. The National Institute of Standards and Technology's program on intelligent processing of metal powders is a multi-disciplinary research initiative investigating the application of intelligent control technologies to improve the state of the art of metal powder manufacturing. This paper reviews the design of the institute's supersonic inert-gas metal-atomizer control system. RP OSELLA, SA (reprint author), NATL INST STAND & TECHNOL,WASHINGTON,DC 20234, USA. NR 12 TC 3 Z9 4 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD JAN PY 1991 VL 43 IS 1 BP 18 EP 21 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA EV648 UT WOS:A1991EV64800003 ER PT J AU SINDERMANN, CJ AF SINDERMANN, CJ TI CASE-HISTORIES OF EFFECTS OF TRANSFERS AND INTRODUCTIONS ON MARINE RESOURCES - INTRODUCTION SO JOURNAL DU CONSEIL LA English DT Editorial Material RP SINDERMANN, CJ (reprint author), NATL MARINE FISHERIES SERV,NORTHEAST FISHERIES CTR,OXFORD LAB,OXFORD,MD 21654, USA. NR 6 TC 7 Z9 7 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0020-6466 J9 J CONSEIL PY 1991 VL 47 IS 3 BP 377 EP 378 PG 2 WC Marine & Freshwater Biology; Multidisciplinary Sciences; Oceanography SC Marine & Freshwater Biology; Science & Technology - Other Topics; Oceanography GA FB343 UT WOS:A1991FB34300009 ER PT J AU NGUYEN, T LIN, CJ AF NGUYEN, T LIN, CJ TI INSITU MEASUREMENT OF CHLORIDE-ION AT THE COATING METAL INTERFACE SO JOURNAL OF ADHESION LA English DT Article DE MECHANISM OF CORROSION; ION SELECTIVE MICROELECTRODES; ANALYTICAL INSTRUMENTATION; BLISTER FORMATION; STEEL; SURFACES ID ORGANIC COATINGS; CORROSION; MECHANISM RP NGUYEN, T (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 14 TC 7 Z9 7 U1 0 U2 3 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 0021-8464 J9 J ADHESION JI J. Adhes. PY 1991 VL 33 IS 4 BP 241 EP 252 DI 10.1080/00218469108026497 PG 12 WC Engineering, Chemical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA FA458 UT WOS:A1991FA45800003 ER PT J AU TINH, NY BYRD, E LIN, CJ AF TINH, NY BYRD, E LIN, CJ TI A SPECTROSCOPIC TECHNIQUE FOR INSITU MEASUREMENT OF WATER AT THE COATING METAL INTERFACE SO JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY LA English DT Article DE ATR; COATINGS; FTIR; INSITU; MULTIPLE INTERNAL REFLECTION SPECTROSCOPY; POLYMER METAL INTERFACE; WATER ID INFRARED-SPECTROSCOPY; SURFACE; VISCOSITY; FORCES AB A technique was developed based on Fourier transform infrared spectroscopy in the multiple internal reflection mode (FTIR-MIR) for measuring in situ water at the coating/metal interface. The technique requires a direct application of a transparent or opaque polymer coating of any thickness to a Ge internal reflection element (IRE). A water chamber was attached to the polymer-coated IRE and water was introduced through the chamber inlet. FTIR-MIR spectra were taken automatically at specified time intervals without realignment or readjustment of the ATR accessory and without disturbing the specimens or the conditions of the experiment. The intensities of the water bands increased and those of the coating bands decreased initially and then leveled off as the exposure times increased. Calculations are presented to demonstrate that the technique can provide information on water at the coating/metal interface. The method may also provide a convenient means for measuring the diffusion of polymer coatings on metals. RP TINH, NY (reprint author), NATL INST STAND & TECHNOL,BLDG 226,ROOM B348,GAITHERSBURG,MD 20899, USA. NR 28 TC 0 Z9 0 U1 1 U2 3 PU VSP BV PI ZEIST PA PO BOX 346, 3700 AH ZEIST, NETHERLANDS SN 0169-4243 J9 J ADHES SCI TECHNOL JI J. Adhes. Sci. Technol. PY 1991 VL 5 IS 9 BP 697 EP 709 PG 13 WC Engineering, Chemical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA GH722 UT WOS:A1991GH72200002 ER PT J AU CHAUMERLIAC, N RICHARD, E ROSSET, R NICKERSON, EC AF CHAUMERLIAC, N RICHARD, E ROSSET, R NICKERSON, EC TI IMPACT OF 2 MICROPHYSICAL SCHEMES UPON GAS SCAVENGING AND DEPOSITION IN A MESOSCALE METEOROLOGICAL MODEL SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID CLOUD DROP GROWTH; COLLECTION; SIMULATION; RAIN; AIR AB Two widely used microphysical schemes are compared to evaluate their possible impact on wet deposition mechanisms. They are based upon different spectral distributions for raindrops (Marshall-Palmer and lognormal distributions) and use different formulations for the autoconversion and evaporation processes, as well as for the fall velocity of raindrops. A comparative study of these two schemes is carried out for a two-dimensional mountain wave simulation in a mesoscale meteorological model. Differences in the spatial and temporal evolution of microphysical fields are investigated. The two schemes are compared for simple chemical scenarios: gas dissolution in cloud and rain, gas scavenging by raindrops, and wet deposition. Results contrast the differing behavior of the two schemes in describing processes such as the direct scavenging of gases by raindrops and the release of chemical species back into the atmosphere because of below-cloud evaporation of rain. C1 NOAA,FORECAST SYST LAB,BOULDER,CO 80303. RP CHAUMERLIAC, N (reprint author), OBSERV PHYS GLOBE CLERMONT FERRAND,ATMOSPHER & METEOROL PHYS LAB,12 AVE LANDAIS,F-6300 CLERMONT FERRAND,FRANCE. RI Richard, Evelyne/G-9506-2011 NR 14 TC 8 Z9 8 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD JAN PY 1991 VL 30 IS 1 BP 88 EP 97 DI 10.1175/1520-0450(1991)030<0088:IOTMSU>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA EZ146 UT WOS:A1991EZ14600005 ER PT J AU GULWADI, SM RAO, MV SIMONS, DS HOLLAND, OW HONG, WP CANEAU, C DIETRICH, HB AF GULWADI, SM RAO, MV SIMONS, DS HOLLAND, OW HONG, WP CANEAU, C DIETRICH, HB TI RANGE STATISTICS AND RUTHERFORD BACKSCATTERING STUDIES ON FE-IMPLANTED IN0.53GA0.47AS SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID HETEROSTRUCTURE INGAASP/INP LASER; SHALLOW P+ LAYER; CO-IMPLANT; ION; P/BE; INP AB Single-energy Fe implantation at energies in the range 50 keV-2MeV to achieve a peak Fe concentration of 1-2x10(18) cm-3 is performed into undoped (n-type) InGaAs layers grown on InP:Fe. The first four statistical moments of the Fe profiles measured by secondary-ion mass spectrometry are determined. The Pearson IV distribution calculated from these moments matches the implant-profile closely. Samples implanted with Fe to doses in the range 5x10(12)-2x10(15) cm-2 at 380 keV are analyzed by Rutherford backscattering measurements to study ion-induced damage. For 380-keV implants, amorphization begins at a dose of almost-equal-to 3 x 10(13)cm-2. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. BELLCORE,RED BANK,NJ 07701. USN,RES LAB,WASHINGTON,DC 20375. RP GULWADI, SM (reprint author), GEORGE MASON UNIV,DEPT ELECT & COMP ENGN,FAIRFAX,VA 22030, USA. NR 25 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 1 PY 1991 VL 69 IS 1 BP 162 EP 167 DI 10.1063/1.347738 PG 6 WC Physics, Applied SC Physics GA ER430 UT WOS:A1991ER43000028 ER PT J AU STAFFORD, TW HARE, PE CURRIE, L JULL, AJT DONAHUE, DJ AF STAFFORD, TW HARE, PE CURRIE, L JULL, AJT DONAHUE, DJ TI ACCELERATOR RADIOCARBON DATING AT THE MOLECULAR-LEVEL SO JOURNAL OF ARCHAEOLOGICAL SCIENCE LA English DT Article DE AMS DATING; C-14 DATING; QUATERNARY EXTINCTIONS ID ASPARTIC-ACID RACEMIZATION; MASS-SPECTROMETRY; ELECTROSTATIC ACCELERATORS; MICROGRAM SAMPLES; FOSSIL BONE; PALEOINDIAN SKELETONS; RADIOISOTOPE ANALYSIS; ORGANIC-MATTER; LAKE-SEDIMENTS; NORTH-AMERICA C1 CARNEGIE INST WASHINGTON, GEOPHYS LAB, WASHINGTON, DC 20015 USA. NIST, CTR ANALYT CHEM, GAITHERSBURG, MD 20899 USA. UNIV ARIZONA, DEPT PHYS, NSF ACCELERATOR FACIL RADIOISOTOPE ANAL, TUCSON, AZ 85721 USA. NR 168 TC 156 Z9 157 U1 0 U2 18 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0305-4403 J9 J ARCHAEOL SCI JI J. Archaeol. Sci. PD JAN PY 1991 VL 18 IS 1 BP 35 EP 72 DI 10.1016/0305-4403(91)90078-4 PG 38 WC Anthropology; Archaeology; Geosciences, Multidisciplinary SC Anthropology; Archaeology; Geology GA ET758 UT WOS:A1991ET75800003 ER PT J AU PETERSON, KI SUENRAM, RD LOVAS, FJ AF PETERSON, KI SUENRAM, RD LOVAS, FJ TI HYDRATION OF CARBON-DIOXIDE - THE STRUCTURE OF H2O-H2O-CO2 FROM MICROWAVE SPECTROSCOPY SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRIC-RESONANCE SPECTROSCOPY; DOPPLER INFRARED-SPECTRUM; WATER DIMER; INTERNAL-ROTATION; COMPLEXES; CATALYSIS; ACID; OCS; HF AB The structure of the gas-phase trimeric complex H2O-H2O-CO2 is determined through an analysis of the rotational spectra of ten isotopically substituted species. These spectra were measured in the region between 7.5 and 18 GHz using a pulsed-molecular-beam Fourier-transform microwave spectrometer. The nondeuterated species display two sets of transitions separated by approximately 1 MHz. The splittings of the perdeuterated form are smaller and three partially deuterated forms have no splittings. The rotational constants for the lower frequency set of transitions of the normal species are A = 6163.571(4) MHz, B = 2226.157(2) MHz, C = 1638.972(1) MHz, delta-J = 0.000 83(3) MHz, DELTA-J = 0.002 98(4) MHz, DELTA-JK = -0.0005(2) MHz. The differences in the rotational constants between the upper and lower states are DELTA-A = 498 kHz, DELTA-B = 520 kHz, and DELTA-C = -133 kHz. The dipole moments are mu-a = 1.571(5) D and mu-b = 0.761(4) D with mu-c = 0 D. The dipole moments and the intertial defect of -0.620 u-angstrom-2 both indicate an essentially planar complex. The structure is found to be cyclical with the dimer-type bond lengths within the trimer being approximately the same as those found in the free heterodimers. One water molecule is oxygen bound to the carbon atom of the CO2 and is also hydrogen bonded to the oxygen of the second water molecule. The second water molecule is in turn hydrogen bonded to one of the oxygens of the CO2 molecule. The observed splittings are most likely due to a hydrogen-exchanging internal rotation of this second water molecule. C1 NIST,DIV MOLEC PHYS,GAITHERSBURG,MD 20899. RP PETERSON, KI (reprint author), UNIV RHODE ISL,DEPT CHEM,KINGSTON,RI 02881, USA. NR 39 TC 32 Z9 32 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 1 PY 1991 VL 94 IS 1 BP 106 EP 117 DI 10.1063/1.460384 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ET473 UT WOS:A1991ET47300013 ER PT J AU LOVEJOY, CM NESBITT, DJ AF LOVEJOY, CM NESBITT, DJ TI ROTATIONAL PREDISSOCIATION, VIBRATIONAL MIXING, AND VANDERWAALS INTERMOLECULAR POTENTIALS OF NEDF SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HIGH-RESOLUTION SPECTROSCOPY; INFRARED-LASER SPECTROSCOPY; AR-HCL; HYDROGEN-FLUORIDE; INTERNAL DYNAMICS; COMPLEXES; SPECTRUM; ARHCL; SYSTEMS; NEHF AB The near-infrared spectrum of NeDF formed in a slit free jet expansion is recorded with a high resolution, tunable laser spectrometer. Four bands, consisting of the DF stretching fundamental and three internal rotation and van der Waals stretch combination bands, are observed and analyzed for both the Ne-20 and Ne-22 isotopomers. All three combination bands reveal a sudden onset of rotational predissociation at modest J, which is modeled with effective one-dimensional potentials to determine the binding energy D0 = 34. 34.7 +/- 0.8 cm-1 for (NeDF)-Ne-20 (upsilon = 0) and D0 = 35.1 +/- 0.8 cm-1 for (NeDF)-Ne-20 (upsilon = 1). The experimental results are compared with predictions of a recently published ab initio anisotropic potential surface, and an improved potential is developed and tested. This refined potential has an absolute minimum of -86 cm-1 in the linear Ne-D-F geometry, a secondary minimum at -55 cm-1 in the inverted linear Ne-F-D geometry, and an intervening saddle point at -39 cm-1 near the perpendicular geometry. The lowest bound state lies almost-equal-to 4 cm-1 above the saddle so internal DF rotation is only slightly hindered in this complex. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP LOVEJOY, CM (reprint author), UNIV COLORADO,NIST,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 37 TC 28 Z9 29 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 1 PY 1991 VL 94 IS 1 BP 208 EP 223 DI 10.1063/1.460379 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ET473 UT WOS:A1991ET47300023 ER PT J AU CASASSA, MP FOY, BR STEPHENSON, JC KING, DS AF CASASSA, MP FOY, BR STEPHENSON, JC KING, DS TI FRAGMENT ENERGY AND VECTOR CORRELATIONS IN THE OVERTONE-PUMPED DISSOCIATION OF HN3 X1A' SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FOURIER-TRANSFORM SPECTROSCOPY; LAMBDA-DOUBLET SELECTIVITY; HYDRAZOIC ACID; SPIN-DOUBLET; PHOTODISSOCIATION; DISTRIBUTIONS; DOPPLER; NH; TRANSITION; DYNAMICS AB NH stretching overtone and combination states in HN3 X approximately 1A' were excited by IR-visible double resonance pumping and by direct overtone pumping in the range 6v1 (17 670 cm-1) to 7v1 (20 070 cm-1). NH fragments in the a 1-delta and X3-SIGMA- states were detected by laser induced fluorescence with sub-Doppler resolution to determine branching ratios, correlated fragment rotational state and kinetic energy distributions, and fragment vector correlations. The spin-forbidden triplet channel was accessible to all states excited, while the threshold for the singlet channel was determined to lie in the range 18 190 to 18 755 cm-1. The measured energy release places limits on the HN-NN bond energy, and the heights of barriers to reaction. The barrier in the singlet exit channel is at least 540 cm-1. The singlet channel accessed by 7v1 dissociation is characterized by a Boltzmann-like NH rotational distribution ([J(NH)] almost-equal-to 3.5) highly excited N2 rotations ([J(N2)] greater-than-or-equal-to 20), and total translational energy release peaked away from zero ([E(T)] almost-equal-to 1350 cm-1). Vector correlations and LAMBDA-doublet propensities indicate that nonplanar dissociation processes influence the NH rotations, but become less important for higher NH rotational states. The principal correlations are a strong positive recoil anisotropy (BETA almost-equal-to 0.6), a weak positive v-J correlation (BETA-vJ almost-equal-to 0.17), and a J(NH)-dependent LAMBDA-doublet propensity. A model using parent vibrational motion projected onto fragment rotation is suggested to explain these observations. The triplet channel exhibits similar NH and N2 rotational state distributions, with most of the available energy (substantially greater than in the singlet channel) appearing as fragment kinetic energy. RP CASASSA, MP (reprint author), NIST,DIV MOLEC PHYS,GAITHERSBURG,MD 20899, USA. NR 47 TC 23 Z9 23 U1 0 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 1 PY 1991 VL 94 IS 1 BP 250 EP 261 DI 10.1063/1.460392 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ET473 UT WOS:A1991ET47300028 ER EF