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1999

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Articles 301 - 330 of 2555

Full-Text Articles in Physical Sciences and Mathematics

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 …


Validity Of The Independent-Particle Approximation In X-Ray Photoemission: The Exception, Not The Rule, D. Hansen, Oliver Hemmers, H. Wang, Dennis W. Lindle, P. Focke, I. A. Sellin, Clemens Heske, H. S. Chakraborty, P. C. Deshmukh, S. T. Manson Oct 1999

Validity Of The Independent-Particle Approximation In X-Ray Photoemission: The Exception, Not The Rule, D. Hansen, Oliver Hemmers, H. Wang, Dennis W. Lindle, P. Focke, I. A. Sellin, Clemens Heske, H. S. Chakraborty, P. C. Deshmukh, S. T. Manson

Environmental Studies Faculty Publications

A combined experimental and theoretical study of argon valence photoionization illustrates the discovery of the broad lack of validity of the independent-particle approximation (IPA) for x-ray photoemission. In addition to previously known breakdowns of the IPA, which are limited to high photon energies and regions very near threshold, the observed breakdown in photoionization at intermediate energies demonstrates generally that the IPA is valid only in very restricted domains. These restrictions are expected to be relevant throughout the periodic table, with consequences for a wide variety of applications.


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 …


Three-Dimensional Reconstructions Of Tadpole Chondrocrania From Histological Sections, Gary P. Radice, Mary Kate Boggiano, Mark Desantis, Peter M. Larson, Joseph Oppong, Matthew T. Smetanick, Todd M. Stevens, James Tripp, Rebecca A. Weber, Michael Kerckhove, Rafael O. De Sá Oct 1999

Three-Dimensional Reconstructions Of Tadpole Chondrocrania From Histological Sections, Gary P. Radice, Mary Kate Boggiano, Mark Desantis, Peter M. Larson, Joseph Oppong, Matthew T. Smetanick, Todd M. Stevens, James Tripp, Rebecca A. Weber, Michael Kerckhove, Rafael O. De Sá

Biology Faculty Publications

Reconstructing three dimensional structures (3DR) from histological sections has always been difficult but is becoming more accessible with the assistance of digital imaging. We sought to assemble a low cost system using readily available hardware and software to generate 3DR for a study of tadpole chondrocrania. We found that a combination of RGB camera, stereomicroscope, and Apple Macintosh PowerPC computers running NIH Image, Object Image, Rotater. and SURFdriver software provided acceptable reconstructions. These are limited in quality primarily by the distortions arising from histological protocols rather than hardware or software.


Measurement Of B0-B̅0 Flavor Oscillations Using Jet-Charge And Lepton Flavor Tagging In Pp̅ Collisions At √S =1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Oct 1999

Measurement Of B0-B̅0 Flavor Oscillations Using Jet-Charge And Lepton Flavor Tagging In Pp̅ Collisions At √S =1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a measurement of the mass difference Δmd for the B0 meson and the statistical power of the b flavor tagging methods used. The measurement uses 90 pb-1 of data from pp̅ collisions at √s =1.8 TeV collected with the CDF detector. An inclusive lepton trigger is used to collect a large sample of B hadron semileptonic decays. The mass difference Δmd is determined from the proper time dependence of the fraction of B hadrons that undergo flavor oscillations. The flavor at decay is inferred from the charge of the lepton from semileptonic …


Mapping A Continental Shelf And Slope In The 1990s: A Tale Of Three Multibeams, James V. Gardner, J.E. Hughes Clarke, Larry A. Mayer, Art Kleiner, Mark Paton Oct 1999

Mapping A Continental Shelf And Slope In The 1990s: A Tale Of Three Multibeams, James V. Gardner, J.E. Hughes Clarke, Larry A. Mayer, Art Kleiner, Mark Paton

Center for Coastal and Ocean Mapping

Increasing societal pressures on the U.S. continental shelves adjacent to dense population centers have brought to light the lack of accurate base maps in these areas. Existing bathymetric maps and random sidescan sonar surveys are either not accurate enough or do not provide the coverage necessary to make policy decisions. Until the mid 1990s, it was not financially prudent nor technically efficient to map the shallow shelves. However, the availability of high-resolution multibeam mapping systems now allow efficient and accurate mapping of the continental margins. In 1996 the U.S. Geological Survey began a large-scale seafloor mapping campaign on the continental …


Data Handling Methods And Target Detection Results For Multibeam And Sidescan Data Collected As Part Of The Search For Swissair Flight 111, John E. Hughes Clarke, Larry A. Mayer, John Shaw, R Parrott, Mike Lamplugh, Jim Bradford Oct 1999

Data Handling Methods And Target Detection Results For Multibeam And Sidescan Data Collected As Part Of The Search For Swissair Flight 111, John E. Hughes Clarke, Larry A. Mayer, John Shaw, R Parrott, Mike Lamplugh, Jim Bradford

Center for Coastal and Ocean Mapping

The crash of SwissAir Flight 111, off Nova Scotia in September 1998, triggered one of the largest seabed search surveys in Canadian history. The primary search tools used were sidescan sonars (both conventional and focussed types) and multibeam sonars. The processed search data needed to be distributed on a daily basis to other elements of the fleet for precise location of divers and other optical seabed search instruments (including laser linescan and ROV video). As a result of the glacial history of the region, many natural targets, similar in gross nature to aircraft debris were present. These included widespread linear …


Collisional Dynamics Of Bi2 A(0U+). I. Quantum-Resolved Vibrational Energy Transfer For V′=0–4, Robert E. Franklin, Glen P. Perram Oct 1999

Collisional Dynamics Of Bi2 A(0U+). I. Quantum-Resolved Vibrational Energy Transfer For V′=0–4, Robert E. Franklin, Glen P. Perram

Faculty Publications

Vibrational-to-translational energy transfer between the lowest vibrational levels (v′=0–4) of the A(0+u) state of Bi2 has been investigated using spectrally resolved, laser-induced fluorescence techniques. The small vibrational spacing (ω′e≃132 cm−1) leads to highly nonadiabatic conditions, particularly for the Bi2(A)–He collision pair. However, the Δv=−1 transition probabilities for collisions with the rare gases range from 0.75% to 1.75% per collision, considerably lower than would be anticipated from standard vibrational energy transfer theory. Multiquantum (Δv′=±2) transfer rates are low, consistent with the low anharmonicity of the A(0+u) state. The rates for …


How Much Justice Hangs In The Balance? A New Look At Hung Jury Rates, Paula Hannaford-Agor, Valerie P. Hans, G. Thomas Munsterman Oct 1999

How Much Justice Hangs In The Balance? A New Look At Hung Jury Rates, Paula Hannaford-Agor, Valerie P. Hans, G. Thomas Munsterman

Cornell Law Faculty Publications

Reports of apparent increases in the number of hung juries in some jurisdictions have caused concern among policy makers. A 1995 report by the California District Attorneys Association cited hung jury rates in 1994 that exceeded 15 percent in some jurisdictions (the rates varied from 3 to 23 percent across the nine counties for which data were available). In 1996, the District of Columbia Superior Court reported a higher-than-expected hung jury rate of 11 percent. Why juries hang at these rates isn't clear, but some commentators have claimed that hung juries are the product of eccentric or nullifying holdout jurors …


กิจกรรมสิ่งแวดล้อม Oct 1999

กิจกรรมสิ่งแวดล้อม

Thai Environment

No abstract provided.


ข่าวสิ่งแวดล้อม Oct 1999

ข่าวสิ่งแวดล้อม

Thai Environment

No abstract provided.


ดัชนีคุณภาพอากาศ, นพภาพร พานิช Oct 1999

ดัชนีคุณภาพอากาศ, นพภาพร พานิช

Thai Environment

No abstract provided.


ความหมายของการพัฒนาอย่างยั่งยืนภายใต้แนวคิดการพัฒนาประเทศ, สุรินทร์ เศรษฐมานิต Oct 1999

ความหมายของการพัฒนาอย่างยั่งยืนภายใต้แนวคิดการพัฒนาประเทศ, สุรินทร์ เศรษฐมานิต

Thai Environment

No abstract provided.


กรณีสารสีส้มและฝนเหลืองที่บ่อฝ้าย : ในทัศนะของนักวิชาการด้านสิ่งแวดล้อม, ทวีศักดิ์ ปิยะกาญน์ Oct 1999

กรณีสารสีส้มและฝนเหลืองที่บ่อฝ้าย : ในทัศนะของนักวิชาการด้านสิ่งแวดล้อม, ทวีศักดิ์ ปิยะกาญน์

Thai Environment

No abstract provided.


แผนปฏิบัติการประชาสัมพันธ์และประมาณค่าใช้จ่ายด้านการจัดการสิ่งแวดล้อมของโครงการ, เสถียร รุจิรวนิช Oct 1999

แผนปฏิบัติการประชาสัมพันธ์และประมาณค่าใช้จ่ายด้านการจัดการสิ่งแวดล้อมของโครงการ, เสถียร รุจิรวนิช

Thai Environment

No abstract provided.


สภาพปัญหาสิ่งแวดล้อมจากอุตสาหกรรมบริเวณพื้นที่ตำบลบางกระดี อำเภอเมือง จังหวัดปทุมธานี, ธนพรรณ สุนทระ Oct 1999

สภาพปัญหาสิ่งแวดล้อมจากอุตสาหกรรมบริเวณพื้นที่ตำบลบางกระดี อำเภอเมือง จังหวัดปทุมธานี, ธนพรรณ สุนทระ

Thai Environment

No abstract provided.


ขยะ "ของร้อน" บนเส้นทางขนานของการพัฒนาเมือง, ธีรพล คังคะเกตุ Oct 1999

ขยะ "ของร้อน" บนเส้นทางขนานของการพัฒนาเมือง, ธีรพล คังคะเกตุ

Thai Environment

No abstract provided.


แนะนำโครงการของสถาบันวิจัยสภาวะแวดล้อม : การเผยแพร่โปรแกรมจัดการสารเคมี (Chemtrack) สู่มหาวิทยาลัย, วรรณี พฤฒิถาวร Oct 1999

แนะนำโครงการของสถาบันวิจัยสภาวะแวดล้อม : การเผยแพร่โปรแกรมจัดการสารเคมี (Chemtrack) สู่มหาวิทยาลัย, วรรณี พฤฒิถาวร

Thai Environment

No abstract provided.


Remote Sensing Of Natural Areas: Procedures And Considerations For Assessing Vegetation Composition Change, Land Development, And Erosion, Jason Goldberg, James Perry, John Anderson, Virginia Institute Of Marine Science, Wetlands Program Oct 1999

Remote Sensing Of Natural Areas: Procedures And Considerations For Assessing Vegetation Composition Change, Land Development, And Erosion, Jason Goldberg, James Perry, John Anderson, Virginia Institute Of Marine Science, Wetlands Program

Reports

No abstract provided.


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 …


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 …


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.


An Xps Study Of The Radiation-Induced Effect On The Thermal Degradation And Charring Of Butadiene And Its Copolymers, Jianwei Hao, Shaoli Wu, Charles Wilkie, Jianqi Wang Oct 1999

An Xps Study Of The Radiation-Induced Effect On The Thermal Degradation And Charring Of Butadiene And Its Copolymers, Jianwei Hao, Shaoli Wu, Charles Wilkie, Jianqi Wang

Chemistry Faculty Research and Publications

A pseudo-in-situ XPS approach shows that cross-linking induced by irradiation may lead to char formation even though it shows only a small or no effect on the onset temperature of degradation.


What Is Y2k And How Did The University Of Nevada System Solve It?, Diane R. Dietrich Oct 1999

What Is Y2k And How Did The University Of Nevada System Solve It?, Diane R. Dietrich

UNLV Theses, Dissertations, Professional Papers, and Capstones

The turn of the century change from 1999 to 2000 will create chaos for the world's computer systems. This paper will discuss the causes of the Y2K problem, the reaction to this problem by the University of Nevada System Computer Services and possible repercussions of this problem for Nevada, the United States and the world.


Shoreline Management In Chesapeake Bay, C. Scott Hardaway Jr., Robert J. Byrne Oct 1999

Shoreline Management In Chesapeake Bay, C. Scott Hardaway Jr., Robert J. Byrne

Reports

This document describes and illustrates specific, practical responses to shoreline management issues. We will begin with a look at the evolution of the Chesapeake Bay and its ongoing, long-term processes. We will proceed to a discussion of the daily, physical mechanisms that affect shoreline change and the topics professionals address in evaluating sites. We will then discuss strategies for managing shorelines, such as bulkheads, seawalls, revetments, groins, breakwaters, beach nourishment, and marsh fringes, as well as taking no action. Finally, we will give you a framework to apply these ideas in terms of the physical environment at the site and …


A Game-Theoretic Formulation Of Multi-Agent Resource Allocation, Jonathan Bredin, Rajiv T. Maheswaran, Cagri Imer, Tamer Basar, David Kotz, Daniela Rus Oct 1999

A Game-Theoretic Formulation Of Multi-Agent Resource Allocation, Jonathan Bredin, Rajiv T. Maheswaran, Cagri Imer, Tamer Basar, David Kotz, Daniela Rus

Computer Science Technical Reports

This paper considers resource allocation in a network with mobile agents competing for computational priority. We formulate this problem as a multi-agent game with the players being agents purchasing service from a common server. We show that there exists a computable Nash equilibrium when agents have perfect information into the future. We simulate a network of hosts and agents using our strategy to show that our resource-allocation mechanism effectively prioritizes agents according to their endowments.


Humic Substances As Interferences In The Analysis Of Nitrite In Water, Stephanie Ann Tebault Oct 1999

Humic Substances As Interferences In The Analysis Of Nitrite In Water, Stephanie Ann Tebault

Chemistry & Biochemistry Theses & Dissertations

Humic substances are of current interest because of their roles in environmental processes involving pollutants. It is also becoming recognized that humic substances may interfere in analysis of environmental samples though the possible adverse effects do not appear to be fully appreciated. The present effort focuses on determining whether humic materials interfere in the analysis of nitrite in water using the Griess reaction. This is a well-known reaction using nitrosation to gjve a diazonium salt followed by coupling with an appropriate reagent to form a dye. This colorimetric method continues to be applied in the laboratory and the field for …


Investigations Of Offshore Beach Sands : Virginia Beach And Sandbridge, Virginia, C. S. Hardaway, C. H. Hobbs Iii, D. A. Milligan Oct 1999

Investigations Of Offshore Beach Sands : Virginia Beach And Sandbridge, Virginia, C. S. Hardaway, C. H. Hobbs Iii, D. A. Milligan

Reports

The City of Virginia Beach is faced with an ongoing problem of erosion along its ocean beaches. The "Resort Strip," the backbone of beach-going tourism in the Commonwealth, must be renourished annually. Steel bulkheads or seawalls have been constructed along most of the 7 km (4.5 mile) ocean shoreline of Sandbridge, a semi-private, ocean-side community. The City is looking for beach material to reestablish its sandy coast. Maintaining a protective and recreational beach is the_primary goal in both locales.

Previous sources of sand for the "Resort Strip" have been upland borrow pits that either have closed or are located too …


Development And Student Use Of Web-Based Prelabs In Analytical Chemistry Courses, Mark Anderson, Brian Tissue Sep 1999

Development And Student Use Of Web-Based Prelabs In Analytical Chemistry Courses, Mark Anderson, Brian Tissue

Mark R. Anderson

No abstract is currently available.


Final Technical Report For The Enhancement Of Autonomous Marine Vehicle Testing In The South Florida Testing Facility Range, South Florida Ocean Measurement Center (Sfomc) Partners Sep 1999

Final Technical Report For The Enhancement Of Autonomous Marine Vehicle Testing In The South Florida Testing Facility Range, South Florida Ocean Measurement Center (Sfomc) Partners

Marine & Environmental Sciences Faculty Reports

The purpose of this grant was to carry out the six scientific experiments on the South Florida Testing Facility (SFTF) Range. In addition to the enhancements to the range, work was performed on all six with some being successfully completed while research continues on the long term tasks.