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1999

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Articles 241 - 270 of 2333

Full-Text Articles in Physical Sciences and Mathematics

Chiral Lagrangian Treatment Of Pi Eta Scattering, Joseph Schechter, Deirdre Black, Amir H. Fariborz Oct 1999

Chiral Lagrangian Treatment Of Pi Eta Scattering, Joseph Schechter, Deirdre Black, Amir H. Fariborz

Physics - All Scholarship

We study pi eta scattering in a model which starts from the tree diagrams of a non-linear chiral Lagrangian including appropriate resonances. Previously, models of this type were applied to pi pi and pi K scattering and were seen to require the existence of light scalar sigma(560) and kappa(900) mesons and to be consistent with the f0(980). The present calculation extends this to include the a0(980), thereby completing a possible nonet of light scalars, all ``seen'' in the same manner. We note that, at the initial level, the pi eta channel is considerably cleaner than the pi pi and pi …


Differential Photometry Of Suspected Cataclysmic Variables, N. Bennert, I. König, E. Manthey, H. Bleul, K. Fieger, M. Hess, A. Hovest, W. Hovest, T. Jürges, J. Kleimann, C. Kriegeskorte, E. Krusch, D. Münstermann, D. Reymann, K. Rösler, M. Nielbock, M. Pohlen, L. Schmidtobreick, C. Tappert, R. Vanscheidt Oct 1999

Differential Photometry Of Suspected Cataclysmic Variables, N. Bennert, I. König, E. Manthey, H. Bleul, K. Fieger, M. Hess, A. Hovest, W. Hovest, T. Jürges, J. Kleimann, C. Kriegeskorte, E. Krusch, D. Münstermann, D. Reymann, K. Rösler, M. Nielbock, M. Pohlen, L. Schmidtobreick, C. Tappert, R. Vanscheidt

Physics

No abstract provided.


Differential Projectile Energy Loss In Multiply Ionizing Collisions, M. Schulz, R. Moshammer, W. Schmitt, H. Kollmus, R. Mann, S. Hagmann, Ronald E. Olson, J. Ullrich Oct 1999

Differential Projectile Energy Loss In Multiply Ionizing Collisions, M. Schulz, R. Moshammer, W. Schmitt, H. Kollmus, R. Mann, S. Hagmann, Ronald E. Olson, J. Ullrich

Physics Faculty Research & Creative Works

The momentum vectors of the recoil ion and up to three electrons were measured in coincidence with the projectiles which did not change charge state for 3.6 MeV amu-1 Au53+ → Ne collisions. New techniques were applied to obtain differential energy-loss spectra for multiple-target ionization as a function of the recoil-ion charge state. A resolution unprecedented for this energy regime was achieved. The data are in good agreement with a classical trajectory Monte Carlo calculation. Our studies represent a first step for a method of modelling stopping powers on a microscopic level and are relevant for plasma applications.


State-To-State Rotational Excitation Of Co By H2 Near 1000 Cm-1 Collision Energy, Stiliana Antonova, Antonis P. Tsakotellis, Ao Lin, George C. Mcbane Oct 1999

State-To-State Rotational Excitation Of Co By H2 Near 1000 Cm-1 Collision Energy, Stiliana Antonova, Antonis P. Tsakotellis, Ao Lin, George C. Mcbane

Peer Reviewed Articles

Relative state-to-state rotationally inelastic cross sections for excitation of carbon monoxide by hydrogen were measured in a crossed molecular beam experiment at collision energies 795, 860, and 991 cm-1. The results are compared to predictions of a recent ab initio potential energy surface [J. Chem. Phys. 108, 3554 (1998)]. The agreement is very good. A comparison with older data on thermally averaged total depopulation cross sections [Chem. Phys. 53, 165 (1980)] indicates that the absolute magnitudes of the cross sections predicted by the surface are too high. The CO excitation is dominated by collisions that are …


Method Of Storing Active Zero Valent Zinc Metal, Reuben D. Rieke Oct 1999

Method Of Storing Active Zero Valent Zinc Metal, Reuben D. Rieke

Department of Chemistry: Faculty Publications

A novel Zerovalent Zinc species and an organozinc reagent are disclosed. The Zerovalent Zinc species is directly pro duced by reaction of a reducing agent on a Zinc Salt, preferably Zn(CN). The organozinc regent results from the reaction of the Zerovalent Zinc species and an organic compound having one or more stable anionic leaving groups. These organozinc reagents include a wide spectrum of functional groups in the organic radical, and are useful in a variety of reactions Schemes.


Macrocyclic Antibiotics As Separation Agents, Daniel W. Armstrong Oct 1999

Macrocyclic Antibiotics As Separation Agents, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

Macrocyclic antibiotics having ring structures with at least 10 members act as separation agents in crystallization, precipitation, filtration, electrophoresis and chromatography. The macrocyclic antibiotics include ansamacrolides, macrolides, macrocyclic peptides, polyenes and derivatives thereof. The process has been found to be especially advantageous for separation of optical isomers by electrophoresis and chromatography.


Phonon And Elastic Instabilities In Moc And Mon, Gus L. W. Hart, Barry M. Klein Oct 1999

Phonon And Elastic Instabilities In Moc And Mon, Gus L. W. Hart, Barry M. Klein

Faculty Publications

We present several results related to the instability of MoC and MoN in the B1 (sodium chloride) structure. These compounds were proposed as potential superconductors with moderately high transition temperatures. We show that the elastic instability in B1-structure MoN, demonstrated several years ago, persists at elevated pressures, thus offering little hope of stabilizing this material without chemical doping. For MoC, another material for which stoichiometric fabrication in the B1 structure has not proven possible, we find that all of the cubic elastic constants are positive, indicating elastic stability. Instead, we find X-point phonon instabilities in MoC (and in MoN as …


North Fork Of The New River Benthic Macroinvertebrate Recruitment Study: Final Report, Charles G. Messing Oct 1999

North Fork Of The New River Benthic Macroinvertebrate Recruitment Study: Final Report, Charles G. Messing

Marine & Environmental Sciences Faculty Reports

Over the last several years, the Broward County Department of Natural Resource Protection has identified a series of major environmental problems in the North Fork of the New River, including illegal wastewater sludge discharge and heavy metal contamination of sediments (DNRP 1993 1994). A qualitative survey suggests that benthic macroinvertebrates have been negatively affected (DNRP 1997). Restoration projects have included removal in the summer of 1997 of a remnant sludge blanket from an area of the channel east of Interstate 95 and north of Broward Boulevard. However, the effectiveness of such dredging in terms of habitat restoration has not previously …


Sar By Ms For Functional Genomics (Structure-Activity Relation By Mass Spectrometry), Bruce Randall Donald, Chris Bailey-Kellogg, John J. Kelley Iii, Cliff Stein Oct 1999

Sar By Ms For Functional Genomics (Structure-Activity Relation By Mass Spectrometry), Bruce Randall Donald, Chris Bailey-Kellogg, John J. Kelley Iii, Cliff Stein

Computer Science Technical Reports

Large-scale functional genomics will require fast, high-throughput experimental techniques, coupled with sophisticated computer algorithms for data analysis and experiment planning. In this paper, we introduce a combined experimental-computational protocol called Structure-Activity Relation by Mass Spectrometry (SAR by MS), which can be used to elucidate the function of protein-DNA or protein-protein complexes. We present algorithms for SAR by MS and analyze their complexity. Carefully-designed Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight (MALDI TOF) and Electrospray Ionization (ESI) assays require only femtomolar samples, take only microseconds per spectrum to record, enjoy a resolution of up to one dalton in $10^6$, and (in the case of …


Isotope Ratio Studies Of Marine Mammals In Prince William Sound, Donald M. Schell, Amy Hirons Oct 1999

Isotope Ratio Studies Of Marine Mammals In Prince William Sound, Donald M. Schell, Amy Hirons

Marine & Environmental Sciences Faculty Reports

No abstract provided.


Simultaneous Photometry And Spectroscopy Of The Newly Discovered Γ Doradus Variable Hr 8330=Hd 207223, Anthony B. Kaye, Gregory W. Henry, Francis C. Fekel, Douglas S. Hall Oct 1999

Simultaneous Photometry And Spectroscopy Of The Newly Discovered Γ Doradus Variable Hr 8330=Hd 207223, Anthony B. Kaye, Gregory W. Henry, Francis C. Fekel, Douglas S. Hall

Information Systems and Engineering Management Research Publications

We present BV photometry and simultaneous high-resolution, high signal-to-noise ratio spectroscopy of the newly-discovered γ Doradus variable HR 8330 taken during the 1997 and 1998 observing seasons. We calculate power spectra for the B- and V-band data sets and for the time series defined throughout the observing season at each point across the Fe iiλ4508.289 and the Ti iiλ4501.278 line profiles to search for periodic variability. Period analysis reveals a single, 2.6-d period in both the photometric and the spectroscopic data, with a 237° phase lag between them. Based on the location of HR 8330 in the HR diagram and …


Preliminary Investigation Of The Extent Of Sediment Contamination In The Lower Grand River, Richard Rediske, Carissa Bertin, Jessica Blunt, Min Qi Oct 1999

Preliminary Investigation Of The Extent Of Sediment Contamination In The Lower Grand River, Richard Rediske, Carissa Bertin, Jessica Blunt, Min Qi

Scientific Technical Reports

A preliminary investigation of the nature and extent of sediment contamination in the lower Grand River was performed. Three areas in the lower Grand River exceeded sediment quality guidelines for heavy metals and selected organic chemicals. The locations and parameters of concern are listed below:

Harbor Island (G20). Exceeds sediment PEL values for chromium, lead, nickel, and DDE in the top core section. Deeper core sections were extensively contaminated with heavy metals.

Spring Lake (G6). Exceeds sediment PEL values for chromium, lead, cadmium, nickel, and DDE.

Grand Haven (G12). Exceeds sediment PEL values for chromium and nickel. The sediments at …


Water Resources Review - Fall 1999 Vol 12 No 2, Annis Water Resources Institute Oct 1999

Water Resources Review - Fall 1999 Vol 12 No 2, Annis Water Resources Institute

AWRI Reviews

No abstract provided.


Earth In Four Dimensions: Development Of The Ideas Of Geologic Time And History, Robert F. Diffendal Jr. Oct 1999

Earth In Four Dimensions: Development Of The Ideas Of Geologic Time And History, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

Changes in ideas and in technology can come about as slow incremental modifications, as well as by major paradigm shifts. In the case of the development of the ideas of geologic history and time, I will try to present these changes broadly and then look at how some of these have affected interpretation of Nebraska geology. Changes of view on three fronts were important in the development of geologic history and time concepts. First is the question of the nature of time. Is time cyclic or is it linear? The Greco-Oriental cultures had a world view based on cosmic cycles, …


Earth In Four Dimensions: Development Of The Ideas Of Geologic Time And History, Robert F. Diffendal Jr. Oct 1999

Earth In Four Dimensions: Development Of The Ideas Of Geologic Time And History, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Changes in ideas and in technology can come about as slow incremental modifications, as well as by major paradigm shifts. In the case of the development of the ideas of geologic history and time, I will try to present these changes broadly and then look at how some of these have affected interpretation of Nebraska geology. Changes of view on three fronts were important in the development of geologic history and time concepts.

First is the question of the nature of time. Is time cyclic or is it linear? The Greco-Oriental cultures had a world view based on cosmic cycles, …


Resource Law Notes Newsletter, No. 47, Fall Issue, 1999, University Of Colorado Boulder. Natural Resources Law Center Oct 1999

Resource Law Notes Newsletter, No. 47, Fall Issue, 1999, University Of Colorado Boulder. Natural Resources Law Center

Resource Law Notes: The Newsletter of the Natural Resources Law Center (1984-2002)

No abstract provided.


High-Order Harmonic Generation In Magnetic And Parallel Magnetic And Electric Fields, Dejan B. Miloševic, Anthony F. Starace Oct 1999

High-Order Harmonic Generation In Magnetic And Parallel Magnetic And Electric Fields, Dejan B. Miloševic, Anthony F. Starace

Anthony F. Starace Publications

We demonstrate control of high-harmonic generation (HHG) by a linearly polarized laser field using uniform static magnetic and electric fields parallel to the laser polarization. We show that the harmonic intensity can be considerably increased for particular values of the magnetic field. The maximum values of the harmonic intensity correspond to such values of magnetic induction for which an integer multiple of the classical cyclotron period of the electron’s motion perpendicular to the magnetic field is equal to the return time of the ionized electron wave packet to the nucleus under the influence of the laser field (and static electric …


Human History As A Natural Science. Review Of: Guns, Germs, And Steel: The Fates Of Human Societies By Jared Diamond, Robert Costanza Oct 1999

Human History As A Natural Science. Review Of: Guns, Germs, And Steel: The Fates Of Human Societies By Jared Diamond, Robert Costanza

Institute for Sustainable Solutions Publications and Presentations

Book review of Guns, Germs, and Steel: The Fates of Human Societies. Jared Diamond. W. W. Norton, New York, 1997.


A Simplified Gaas Polarized Electron Source, H. M. Al-Khateeb, B. G. Birdsey, T. C. Bowen, A. S. Green, M. E. Johnston, Timothy J. Gay Oct 1999

A Simplified Gaas Polarized Electron Source, H. M. Al-Khateeb, B. G. Birdsey, T. C. Bowen, A. S. Green, M. E. Johnston, Timothy J. Gay

Timothy J. Gay Publications

We report operational and construction details of a simplified GaAs polarized electron source. It is contained in a modified 4.63 in. Conflat four-way cross, and uses a single 56 ℓ /s turbomolecular pump. The design incorporates multiple cesiators to extend source lifetime, a new spring-clamp GaAs crystal mounting design to provide uniform crystal heating, and a very simple tubular 90° electrostatic deflector. We also discuss matters related to preparing, heat cleaning, and activating the GaAs crystal.


Observations Of Shallow Groundwater Contamination Due To Leakage Of Dairy Effluent Ponds On The Swan Coastal Plain, Wa, Richard J. George Dr, D L. Bennett, J R M Bell, Roger Wrigley Oct 1999

Observations Of Shallow Groundwater Contamination Due To Leakage Of Dairy Effluent Ponds On The Swan Coastal Plain, Wa, Richard J. George Dr, D L. Bennett, J R M Bell, Roger Wrigley

Resource management technical reports

In response to the risk of pollution of surface water from farm runoff, dairy farmers have been encouraged to install effluent storage ponds. Previous research has indicated that leachate from these storages can contribute to groundwater contamination. This project assessed the performance of storages at eight sites on the Swan Coastal Plain (SCP), WA. Groundwater conditions were monitored for over three years to study the influence of soil type, water table depth and waste water characteristics.


Water Current, Volume 31, No. 5, October 1999 Oct 1999

Water Current, Volume 31, No. 5, October 1999

Water Current Newsletter

Fall NWCC Meeting Well Attended
From the Director
Wyoming Development Fund Highlighted on Four States Irrigation Summer Tour
Center Pivot Inventory Map
Husker Harvest Days Winners
Status of Cooperative Agreement After Two Years
The Definitions of Science
Water News Briefs
New EPA Bioremediation Site
GovSpot Offers Best in Government and Civic Web Info
Source Water Assessment and Protection Workshop Guide Available Free from the Groundwater Foundation
Hazard Web Sites
"Watershed 2000" Call for Papers
Water Resources Lecture Series Addresses Interstate Water Commitments


Enhanced Biotransformation Of Carbon Tetrachloride By Acetobacterium Woodii Upon Addition Of Hydroxocobalamin And Fructose, Syed A. Hashsham, David L. Freedman Oct 1999

Enhanced Biotransformation Of Carbon Tetrachloride By Acetobacterium Woodii Upon Addition Of Hydroxocobalamin And Fructose, Syed A. Hashsham, David L. Freedman

Publications

The objective of this study was to evaluate the effect of hydroxocobalamin (OH-Cbl) on transformation of high concentrations of carbon tetrachloride (CT) by Acetobacterium woodii (ATCC 29683). Complete transfor-mation of 470 􀀀M (72 mg/liter [aqueous]) CT was achieved by A. woodii within 2.5 days, when 10 􀀀M OH-Cbl was added along with 25.2 mM fructose. This was approximately 30 times faster than A. woodii cultures (live or autoclaved) and medium that did not receive OH-Cbl and 5 times faster than those controls that did receive OH-Cbl, but either live A. woodii or fructose was missing. CT transformation in treatments with …


Gray Whales (Eschrichtius Robustus) Off Sakhalin Island, Russia: Seasonal And Annual Patterns Of Occurrence, David Weller, Bernd Wursig, Amanda Bradford, Alexander Burdin, Sergey Blokhin, Hiroya Minakuchi, Robert L. Brownell Jr. Oct 1999

Gray Whales (Eschrichtius Robustus) Off Sakhalin Island, Russia: Seasonal And Annual Patterns Of Occurrence, David Weller, Bernd Wursig, Amanda Bradford, Alexander Burdin, Sergey Blokhin, Hiroya Minakuchi, Robert L. Brownell Jr.

United States Department of Commerce: Staff Publications

The annual return, seasonal occurrence, and site fidelity of Korean-Okhotsk or western gray whales on their feeding grounds off northeastern Sakhalin Island, Russia, were assessed by boat-based photo-identification studies in 1994-1998. A total of 262 pods were observed, ranging in size from 1 to 9 whales with an overall mean of 2.0'. Sixty-nine whales were individually identified, and a majority of all whales (71.0%) were observed in multiple years. Annual sighting frequencies ranged from 1 to 18 d, with a mean of 5.4 d. The percentage of whales re-identified from previous years showed a continuous annual increase, reaching 87.0% by …


Metadata In A Digital Special Library: The Energy And Environmental Information Resources Center In Lafayette, Louisiana, Dan Foley Oct 1999

Metadata In A Digital Special Library: The Energy And Environmental Information Resources Center In Lafayette, Louisiana, Dan Foley

E-JASL: Electronic Journal of Academic and Special Librarianship (1999-2009, Volumes 1-10)

This paper discusses three kinds of metadata and how they are used in the Energy & Environmental Information Resources Center (EE-IR Center), a digital special library of text, numeric, and geospatial data, located in Lafayette, Louisiana. These metadata are Dublin Core (DC), MARC21 (formerly USMARC), and Federal Geographic Data Committee (FGDC) metadata.

The EE-IR Center was formed as a partnership between the National Wetlands Research Center (NWRC) of the U.S. Geological Survey and the Center for Advanced Computer Studies of the University of Southwestern Louisiana (CACS/USL). Both partners are located in Lafayette, Louisiana. The EE-IR Center is funded by a …


Impact Of Transmission Impairments On The Teletraffic Performance Of Wavelength-Routed Optical Networks, Byrav Ramamurthy, Debasish Datta, Helena Feng, Jonathan P. Heritage, Biswanath Mukherjee Oct 1999

Impact Of Transmission Impairments On The Teletraffic Performance Of Wavelength-Routed Optical Networks, Byrav Ramamurthy, Debasish Datta, Helena Feng, Jonathan P. Heritage, Biswanath Mukherjee

School of Computing: Faculty Publications

In a wavelength-routed optical network, a transmitted signal remains in the optical domain over the entire route (lightpath) assigned to it between its source and destination nodes. The optical signal may have to traverse a number of crossconnect switches (XCS’s), fiber segments, and optical amplifiers, e.g., erbium-doped fiber amplifiers (EDFA’s). Thus, while propagating through the network, the signal may degrade in quality as it encounters crosstalk at the XCS’s and also picks up amplified spontaneous emission (ASE) noise at the EDFA’s. Since these impairments continue to degrade the signal quality as it progresses toward its destination, the received bit error …


Parity Nonconservation In 106pd And 108pd Neutron Resonances, Bret E. Crawford, J D. Bowman, P P J. Delheij, T Haseyama, J N. Knudsen, L Y. Lowie, A Masaike, Y Matsuda, G E. Mitchell, S I. Penttila, H Postma, N R. Roberson, S J. Seestrom, E I. Sharapov, Sharon L. Stephenson, V W. Yuan Oct 1999

Parity Nonconservation In 106pd And 108pd Neutron Resonances, Bret E. Crawford, J D. Bowman, P P J. Delheij, T Haseyama, J N. Knudsen, L Y. Lowie, A Masaike, Y Matsuda, G E. Mitchell, S I. Penttila, H Postma, N R. Roberson, S J. Seestrom, E I. Sharapov, Sharon L. Stephenson, V W. Yuan

Physics and Astronomy Faculty Publications

Parity nonconservation (PNC) has been studied in the neutron p-wave resonances of 106Pd and 108Pd in the energy range of 20 to 2000 eV. Longitudinal asymmetries in p-wave capture cross sections are measured using longitudinally polarized neutrons incident on ∼20-g metal-powder targets at LANSCE. A CsI γ-ray detector array measures capture cross section asymmetries as a function of neutron energy which is determined by the neutron time-of-flight method. A total of 21 p-wave resonances in 106Pd and 21 p-wave resonances in 108Pd were studied. One statistically significant PNC effect was observed in106Pd, and no …


Fall 1999, Nsu Oceanographic Center Oct 1999

Fall 1999, Nsu Oceanographic Center

Currents

No abstract provided.


A Scintillating Plastic Fiber Tracking Detector For Neutron And Proton Imaging And Spectroscopy, James M. Ryan, John R. Macri, Mark L. Mcconnell, Richard A. Messner, Wenhui Li, Hansford H. Cutlip, Quihua Zheng, Carlos Castaneda, Juan L. Romero Oct 1999

A Scintillating Plastic Fiber Tracking Detector For Neutron And Proton Imaging And Spectroscopy, James M. Ryan, John R. Macri, Mark L. Mcconnell, Richard A. Messner, Wenhui Li, Hansford H. Cutlip, Quihua Zheng, Carlos Castaneda, Juan L. Romero

Space Science Center

We report the results of recent calibration data analysis of a prototype scintillating fiber tracking detector system designed to perform imaging, spectroscopy and particle identification on 20 to 250 MeV neutrons and protons. We present the neutron imaging concept and briefly review the detection principle and the prototype description. The prototype detector system records ionization track data on an event-by-event basis allowing event selection criteria to be used in the off-line analysis. Images of acrylic phantoms from the analysis of recent proton beam calibrations (14 to 65 MeV range) are presented as demonstrations of the particle identification, imaging and energy …


Diagenesis Of Lower Cretaceous Pelagic Carbonates, North Atlantic: Paleoceanographic Signals Obscured, Tracy D. Frank, Michael A. Arthur, Walter E. Dean Oct 1999

Diagenesis Of Lower Cretaceous Pelagic Carbonates, North Atlantic: Paleoceanographic Signals Obscured, Tracy D. Frank, Michael A. Arthur, Walter E. Dean

Department of Earth and Atmospheric Sciences: Faculty Publications

The stable isotope and minor element geochemistry of Neocomian (Lower Cretaceous) pelagic carbonates of the North Atlantic Basin (Deep Sea Drilling Project Sites 105, 367, 387, 391, and 603) was examined to develop a diagenetic model for pelagic limestones. In particular, we hoped to test the fidelity of whole-rock geochemical records as paleoceanographic indicators for pelagic deposits of pre-Aptian age, in which individual microfossils are not available for analysis. Data indicate that in addition to depth of burial, rhythmic variations in primary carbonate content have strongly controlled diagenetic patterns and associated geochemical signatures in these Neocomian sequences. Samples become increasingly …


1999 Scholars And Artists Bibliography, Michael Schwartz Library, Cleveland State University, Friends Of The Michael Schwartz Library Oct 1999

1999 Scholars And Artists Bibliography, Michael Schwartz Library, Cleveland State University, Friends Of The Michael Schwartz Library

Scholars and Artists Bibliographies

This bibliography was created for the annual Friends of the Michael Schwartz Library Scholars and Artists Reception, recognizing scholarly and creative achievements of Cleveland State University faculty, staff and emeriti