Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2001

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 1321 - 1350 of 3030

Full-Text Articles in Physical Sciences and Mathematics

Hydrography, Nutrients, And Carbon Pools In The Pacific Sector Of The Southern Ocean: Implications For Carbon Flux, Kendra L. Daly, Walker O. Smith Jr., Gregory C. Johnson, Et Al Apr 2001

Hydrography, Nutrients, And Carbon Pools In The Pacific Sector Of The Southern Ocean: Implications For Carbon Flux, Kendra L. Daly, Walker O. Smith Jr., Gregory C. Johnson, Et Al

VIMS Articles

PDF Tools Share

Abstract

We investigated the hydrography, nutrients, and dissolved and particulate carbon pools in the western Pacific sector of the Antarctic Circumpolar Current (ACC) during austral summer 1996 to assess the region's role in the carbon cycle. Low f CO2 values along two transects indicated that much of the study area was a sink for atmospheric CO2. The f CO2 values were lowest near the Polar Front (PF) and the Subtropical Front (STF), concomitant with maxima of chlorophyll a and particulate and dissolved organic carbon. The largest biomass accumulations did not occur at fronts, …


Double-Electron Removal From H2 By Slow, Highly Charged Xe²³⁺ Ions, Ronald E. Olson, C. R. Feeler Apr 2001

Double-Electron Removal From H2 By Slow, Highly Charged Xe²³⁺ Ions, Ronald E. Olson, C. R. Feeler

Physics Faculty Research & Creative Works

A five-body classical trajectory Monte Carlo model has been used to study double-electron removal from H2 by collisions with highly charged ions. The final-state correlations between ionized protons and projectile are calculated for Xe23+ impact on H2 at collisions energies ranging from 2.6 eVu-1 to 2.6 keVu-1. In the center-of-mass frame of the recoiling protons, as the projectile energy decreases the proton energy distribution broadens considerably and also shifts to lower energies relative to that for an isolated molecule Franck-Condon transition. At low collision energies the protons are found to be scattered to the forward direction …


Observations Of Volcanic Clouds In Their First Few Days Of Atmospheric Residence: The 1992 Eruptions Of Crater Peak, Mount Spurr Volcano, Alaska, William I. Rose, Gregg J. Bluth, David J. Schneider, Gerald G. J. Ernst, Colleen M. Riley, Lydia J. Henderson, Robert G. Mcgimsey Apr 2001

Observations Of Volcanic Clouds In Their First Few Days Of Atmospheric Residence: The 1992 Eruptions Of Crater Peak, Mount Spurr Volcano, Alaska, William I. Rose, Gregg J. Bluth, David J. Schneider, Gerald G. J. Ernst, Colleen M. Riley, Lydia J. Henderson, Robert G. Mcgimsey

Department of Geological and Mining Engineering and Sciences Publications

Satellite SO2 and ash measurements of Mount Spurr’s three 1992 volcanic clouds are compared with ground‐based observations to develop an understanding of the physical and chemical evolution of volcanic clouds. Each of the three eruptions with ratings of volcanic explosivity index three reached the lower stratosphere (14 km asl), but the clouds were mainly dispersed at the tropopause by moderate to strong (20–40 m/s) tropospheric winds. Three stages of cloud evolution were identified. First, heavy fallout of large (>500 μm) pyroclasts occurred close to the volcano (vent) during and immediately after the eruptions, and the cloud resembled an advected …


Temporal Decomposition For Low Rate Wideband Speech Compression, C. H. Ritz, I. Burnett Apr 2001

Temporal Decomposition For Low Rate Wideband Speech Compression, C. H. Ritz, I. Burnett

Faculty of Informatics - Papers (Archive)

An investigation into low bit rate wideband speech coding for applications such as unicast streaming is presented. Wideband spectral parameters are quantised below 1 kbit/s using temporal decomposition (TD) applied to the line spectral frequencies. Quantisation using TD performs significantly better than split vector quantisation at an equivalent bit rate.


First Results From The Anglo-Australian Planet Search: A Brown Dwarf Candidate And A 51 Peg-Like Planet, Chris G. Tinney, R. Paul Butler, Geoffrey W. Marcy, Hugh R. A. Jones, Alan J. Penny, Steve S. Vogt, Kevin Apps, Gregory W. Henry Apr 2001

First Results From The Anglo-Australian Planet Search: A Brown Dwarf Candidate And A 51 Peg-Like Planet, Chris G. Tinney, R. Paul Butler, Geoffrey W. Marcy, Hugh R. A. Jones, Alan J. Penny, Steve S. Vogt, Kevin Apps, Gregory W. Henry

Information Systems and Engineering Management Research Publications

We report results from the Anglo-Australian Planet Search, a survey for planets around 200 solar-type stars in the southern hemisphere that is being carried out on the 3.9 m Anglo-Australian Telescope. Limiting Doppler precisions of 3 m s-1 have been demonstrated from the first 2.5 years of operation, making this the highest-precision planet search in the southern hemisphere. From these data we report results for two new substellar detections. The first is a 51 Peg-like planet around the star HD 179949 with M sin i = 0.84 MJUP. Photometric study reveals this is not a transiting system. The second is …


Use Of Acetaminophen For Large-Scale Control Of Brown Treesnakes, Peter J. Savarie, John A. Shivik, Gary C. White, Jerome C. Hurley, Larry Clark Apr 2001

Use Of Acetaminophen For Large-Scale Control Of Brown Treesnakes, Peter J. Savarie, John A. Shivik, Gary C. White, Jerome C. Hurley, Larry Clark

United States Department of Agriculture Wildlife Services: Staff Publications

Because the brown treesnake (Boiga irregularis) has virtually extirpated the avifauna on Guam and is a threat to other Pacific islands, the development of alternative and efficient control methods is required. Therefore, we performed a large-scale field experiment to determine whether the acetaminophen baits we developed could be used to reduce population levels of brown treesnakes on Guam. Toxic baits were made by inserting 80 mg of acetaminophen into dead neonatal mice, and these mouse baits were used to treat plots. Reference plots were baited with unadulterated baits. We used mark-recapture methods to estimate snake abundance on plots …


First Measurement Of The Ratio B (TWb)/ B (TWq) And Associated Limit On The Cabibbo-Kobayashi-Maskawa Element |VTb|, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Apr 2001

First Measurement Of The Ratio B (T →Wb)/ B (T → Wq) And Associated Limit On The Cabibbo-Kobayashi-Maskawa Element |VTb|, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present the first measurement of the ratio of branching fractions RB(tWb)/B(tWq) from pp̅ collisions at √s =1.8 TeV. The data set corresponds to 109 pb-1 of data recorded by the Collider Detector at Fermilab during the 1992–95 Tevatron run. We measure R=-0.24+0.31(stat + syst) or R >0.61 (0.56) at 90% (95)% C.L., in agreement with the standard model predictions. This measurement yields a limit on the Cabibbo-Kobayashi-Maskawa quark mixing matrix element |Vtb| under the assumption of three generations …


Blowup In A Mass-Conserving Convection-Diffusion Equation With Superquadratic Nonlinearity, Todd L. Fisher, Christopher P. Grant Apr 2001

Blowup In A Mass-Conserving Convection-Diffusion Equation With Superquadratic Nonlinearity, Todd L. Fisher, Christopher P. Grant

Faculty Publications

A nonlinear convection-diffusion equation with boundary conditions that conserve the spatial integral of the solution is considered. Previous results on nite-time blowup of solutions and on decay of solutions to the corresponding Cauchy problem were based on the assumption that the nonlinearity obeyed a power law. In this paper, it is shown that assumptions on the growth rate of the nonlinearity, which take the form of weak superquadraticity and strong superlinearity criteria, are suffcient to imply that a large class of nonnegative solutions blow up in nite time.


Agenda: A Cartography Of Governance: Exploring The Province Of Environmental Ngos, University Of Colorado Boulder. School Of Law, University Of Colorado Boulder. Environmental Program, University Of Tulsa. National Energy-Environment Law & Policy Institute, University Of Colorado Boulder. United Government Of Graduate Students Apr 2001

Agenda: A Cartography Of Governance: Exploring The Province Of Environmental Ngos, University Of Colorado Boulder. School Of Law, University Of Colorado Boulder. Environmental Program, University Of Tulsa. National Energy-Environment Law & Policy Institute, University Of Colorado Boulder. United Government Of Graduate Students

A Cartography of Governance: Exploring the Province of Environmental NGOs (April 7-8)

Presented by: the Colorado Journal of International Environmental Law and Policy on April 7 & 8, 2001. Symposium director: Lakshman D. Guruswamy.

Co-sponsored by: University of Colorado School of Law, University of Colorado Environmental Program, University of Tulsa National Energy-Environment Law and Policy Institute, University of Colorado United Government of Graduate Students.

The papers and edited proceedings of the conference will be published in a special symposium issue of the Colorado Journal of International Environmental Law & Policy (CJIELP).

"The first objective of the Symposium was to understand and explore the growing importance of nongovernmental actors, and delineate the manner …


Globalization And The Nation State, Jayantha Dhanapala Apr 2001

Globalization And The Nation State, Jayantha Dhanapala

A Cartography of Governance: Exploring the Province of Environmental NGOs (April 7-8)

15 pages.


The United Nations And Civil Society, Jayantha Dhanapala Apr 2001

The United Nations And Civil Society, Jayantha Dhanapala

A Cartography of Governance: Exploring the Province of Environmental NGOs (April 7-8)

7 pages.


Oxidation Of Zeaxanthin And Characterization Of 3'-Alkyl Lutein Ethers, Jie Chi Apr 2001

Oxidation Of Zeaxanthin And Characterization Of 3'-Alkyl Lutein Ethers, Jie Chi

FIU Electronic Theses and Dissertations

One purpose of this study was to understand the oxidation metabolites of zeaxanthin, another was to prepare, purify, and characterize a series of 3'-alkyl lutein ethers for use as internal standards.

Studies have proven that lutein and zeaxanthin are two of the principal carotenoids in human serum and the only carotenoids found in the retina, but their metabolism and transport in the human body are still only poorly understood. In vitro oxidation of zeaxanthin with MnO2 produced three components. They were characterized by HPLC, UV/Vis, MS, NMR and identified as all-trans rhodoxanthin and its cis-isomers.

3'-alkyl lutein ethers have …


Trends. Cognitive Dissonance And Conflation Of Patriotism And Political Advocacy: On The Secrecy Of The Intelligence Budget, Ibpp Editor Apr 2001

Trends. Cognitive Dissonance And Conflation Of Patriotism And Political Advocacy: On The Secrecy Of The Intelligence Budget, Ibpp Editor

International Bulletin of Political Psychology

This article discusses the views of the Federation of American Scientists (FAS) regarding the budgeting practices of the U.S. Central Intelligence Agency (CIA).


Determination Of Lysophosphatidic Acids By Capillary Electrophoresis With Indirect Ultraviolet Detection, Yi Lung Chen, Yan Xu Apr 2001

Determination Of Lysophosphatidic Acids By Capillary Electrophoresis With Indirect Ultraviolet Detection, Yi Lung Chen, Yan Xu

Chemistry Faculty Publications

Lysophosphatidic acid (LPA) is the simplest form of lysophospholipid. Molecular species of LPA have been identified as the potent components in the ovarian cancer activation factor. The elevated plasma LPAs may be used as potential biomarkers for the early detection of ovarian cancer. This paper is the first report on the quantitative analysis of molecular species of LPA using capillary electrophoresis. In this work, the separation of LPAs was achieved within 14 min in an adenosine monophosphate-borate–methanol–water solution, and the measurement was accomplished by indirect UV detection. With LPA (D) as internal standard, the method had linear calibration ranges for …


Search For Dilepton Signatures From Minimal Low-Energy Supergravity In Pp̅ Collisions At √S = 1.8 Tev, B. Abbott, Gregory R. Snow, D0 Collaboration Apr 2001

Search For Dilepton Signatures From Minimal Low-Energy Supergravity In Pp̅ Collisions At √S = 1.8 Tev, B. Abbott, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

We report on a search for supersymmetry using the DØ detector. The 1994–1996 data sample of √s =1.8 TeV pp̅ collisions was analyzed for events containing two leptons (e or μ), two or more jets, and missing transverse energy. Assuming the minimal supergravity model, with A0=0 and μ < 0, various thresholds were employed to optimize the search. No events were found beyond expectation from the background. We set a lower limit at the 95% C.L. of 255 GeV/c2 for equal mass squarks and gluinos for tan β =2, and present exclusion contours in the (m0 , m1/2) plane for tan β =2–6.


Addressing Uncertainty In Tmdls: Short Course At Arkansas Water Resources Center 2001 Annual Conference, Marty Matlock, Matthew Murawski Apr 2001

Addressing Uncertainty In Tmdls: Short Course At Arkansas Water Resources Center 2001 Annual Conference, Marty Matlock, Matthew Murawski

Technical Reports

Management of a critical natural resource like water requires information on the status of that resource. The US Environmental Protection Agency (EPA) reported in the 1998 National Water Quality Inventory that more than 291,000 miles of assessed rivers and streams and 5 million acres of lakes do not meet State water quality standards. This inventory represents a compilation of State assessments of 840,000 miles of rivers and 17.4 million acres of lakes; a 22 percent increase in river miles and 4 percent increase in lake acres over their 1996 reports. Siltation, bacteria, nutrients and metals were the leading pollutants of …


A Search For Previously Unrecognized Metal-Poor Subdwarfs In The Hipparcos Astrometric Catalogue, I. N. Reid, F. Van Wyk, F. Marang, G. Roberts, D. Kilkenny, S. Mahoney Apr 2001

A Search For Previously Unrecognized Metal-Poor Subdwarfs In The Hipparcos Astrometric Catalogue, I. N. Reid, F. Van Wyk, F. Marang, G. Roberts, D. Kilkenny, S. Mahoney

Dartmouth Scholarship

We have identified 317 stars included in the Hipparcos astrometric catalogue that have parallaxes measured to a precision of better than 15 per cent, and the location of which in the (MV,(B−V)T) diagram implies a metallicity comparable to or less than that of the intermediate‐abundance globular cluster M5. We have undertaken an extensive literature search to locate Strömgren, Johnson/Cousins and Walraven photometry for over 120 stars. In addition, we present new UBV(RI)C photometry of 201 of these candidate halo stars, together with similar data for a further 14 known metal‐poor subdwarfs. These …


Management, Retrieval, And Visualization Of Spatial Data From Airborne Light Detection And Ranging System (Lidar) Survey, Zheng Cui Apr 2001

Management, Retrieval, And Visualization Of Spatial Data From Airborne Light Detection And Ranging System (Lidar) Survey, Zheng Cui

FIU Electronic Theses and Dissertations

The primary purpose of this research was to develop new methodologies to process and analyze large amount of topographic data from airborne LIDAR (light detection and ranging) survey.

This research developed a suite of algorithms to resample dense clouds of point data from LIDAR survey, cut the large data set into smaller tiles, and filtered data to remove points from non-ground surface features such as vegetations, buildings, and vehicles. These algorithms were implemented on the PC platform using C++. The test results showed that the developed application software package based on these algorithms worked well. This application software package provided …


The Teaching Marsh : A Tidal Wetland Restoration & Education Project, William Roberts, Karen Duhring Apr 2001

The Teaching Marsh : A Tidal Wetland Restoration & Education Project, William Roberts, Karen Duhring

Miscellaneous

The Teaching Marsh at the Virginia Institute of Marine Science is a one acre site restored to marshland for both practical and educational purposes. The marsh is designed and maintained by VIMS wetlands experts to naturally remove contaminants from Coleman Bridge storm water runoff, improving water quality in the York River.

The brochure describes the development, site, and plants selected for the field project.


From The Director: Spring 2001, Donald A. Wilhite Apr 2001

From The Director: Spring 2001, Donald A. Wilhite

Drought Network News (1994-2001)

I recently participated in an advanced course, “Management Strategies to Mitigate Drought in the Mediterranean: Monitoring, Risk Analysis, and Contingency Planning”, in Rabat, Morocco (May 21– 26). The course was organized by the Mediterranean Agronomic Institute of Zaragoza (CIHEAM– IAMZ) and the Institut Agronomique et Veterinaire Hassan II in Rabat, Morocco, with contribution from the European Commission. The National Drought Mitigation Center’s Mark Svoboda also participated. Other lecturers included M. Wassif (Desert Research Center, Cairo); Eddy dePauw (ICARDA); Ana Iglesias (Universidad Politecnica, Madrid, and Center for Climate Systems Research, Columbia University); Karl Monnik (Institute for Soil, Climate and Water/ARC, South …


Water Current, Volume 33, No. 2. April 2001 Apr 2001

Water Current, Volume 33, No. 2. April 2001

Water Current Newsletter

• Simple Sampler Assesses Buffer Strip Effectiveness by Steve Ress

• From the Director

• Meet the Faculty

• CLEAR Offers Help Restoring Community Lakes by Steve Ress

• UNL Water Lab Participates in NRD Water Programs Conference

• Summer Water and Natural Resources Tour Looks at Urban Water Quality and Quantity Concerns by Steve Ress

• 30th Annual Water Conference Held at Grand Island’s I-80 Holiday Inn by Steve Ress

• On the Subject of Lawns

• Irrigation, by the Numbers

• Water News Briefs


Mage: A Distributed Programming Model, Earl Barr, Raju Pandey, Michael Haungs Apr 2001

Mage: A Distributed Programming Model, Earl Barr, Raju Pandey, Michael Haungs

Computer Science and Software Engineering

Writing distributed programs is difficult. To ease this task, we introduce a new programming abstraction. which we call a mobility attribute. Mobility attributes provide a syntax that describes the mobility semantics of program components. Programmers attach mobility attributes to program components to dynamically control the placement of these components within the network. Mobility attributes intercept component invocations and decide whether and where to move a component before the component executes. This allows the programmer to improve her program's run-time efficiency by colocating components and resources. We present MAGE, an object oriented distributed system, that supports mobility attributes and illustrates their …


Gps-Determination Of Along-Strike Variation In Cascadia Margin Kinematics: Implications For Relative Plate Motion, Subduction Zone Coupling, And Permanent Deformation, M. Meghan Miller, Daniel J. Johnson, Charles M. Rubin, Herb Dragert, Kelin Wang, Anthony Qamar, Chris Goldfinger Apr 2001

Gps-Determination Of Along-Strike Variation In Cascadia Margin Kinematics: Implications For Relative Plate Motion, Subduction Zone Coupling, And Permanent Deformation, M. Meghan Miller, Daniel J. Johnson, Charles M. Rubin, Herb Dragert, Kelin Wang, Anthony Qamar, Chris Goldfinger

All Faculty Scholarship for the College of the Sciences

High‐precision GPS geodesy in the Pacific Northwest provides the first synoptic view of the along‐strike variation in Cascadia margin kinematics. These results constrain interfering deformation fields in a region where typical earthquake recurrence intervals are one or more orders of magnitude longer than the decades‐long history of seismic monitoring and where geologic studies are sparse. Interseismic strain accumulation contributes greatly to GPS station velocities along the coast. After correction for a simple elastic dislocation model, important residual motions remain, especially south of the international border. The magnitude of northward forearc motion increases southward from western Washington (3–7 mm/yr) to northern …


Circulation, Vol. 8, No. 1, Center For Coastal Physical Oceanography, Old Dominion University, Ann E. Gargett Apr 2001

Circulation, Vol. 8, No. 1, Center For Coastal Physical Oceanography, Old Dominion University, Ann E. Gargett

CCPO Circulation

Spring 2001 issue of CCPO Circulation featuring article "Remarks from a New Arrival: Dr. Ann Gargett"


Ice Storm Damage To Virginia Coastal Plain Forests During The Christmas 1998 Ice Storm, Peter Elstner, Stewart Ware Apr 2001

Ice Storm Damage To Virginia Coastal Plain Forests During The Christmas 1998 Ice Storm, Peter Elstner, Stewart Ware

Virginia Journal of Science

On December 23-25, 1998, a major ice storm struck southeastern Virginia. The storm-deposited glaze ice felled trees and limbs, causing a power outage and highway blockage. Between February and April, 1999, we recorded occurrence, severity, and type of damage to trees over 2.5 cm dbh in nine mostly gently sloping plots in Matoaka Woods at the College of William and Mary. Frequency and severity of damage varied with species and with size of trees. Canopy damage occurred in 75% of large Fagus grandifolia trees, but in only 6% of small Sassafras albidum stems. As a group, small (2.5 to 15 …


Trachelomonas Spp. And Other Euglenophyceae Taxa In A Southeastern Virginia Lake, Harold G. Marshall Apr 2001

Trachelomonas Spp. And Other Euglenophyceae Taxa In A Southeastern Virginia Lake, Harold G. Marshall

Virginia Journal of Science

Trachelomonas species from Lake Kilby, a reservoir lake in southeastern Virginia are described with supportive electron micrographs. The most abundant Trachelomonas species wereT. hispida and T. volvocina. Other members of the Euglenophyceae occurring in this lake are identified.


Abstracting Aristotle’S Philosophy Of Mathematics, John J. Cleary Apr 2001

Abstracting Aristotle’S Philosophy Of Mathematics, John J. Cleary

Research Resources

In the history of science perhaps the most influential Aristotelian division was that

between mathematics and physics. From our modern perspective this seems like an unfortunate deviation from the Platonic unification of the two disciplines, which guided Kepler and Galileo towards the modern scientific revolution. By contrast, Aristotle’s sharp distinction between the disciplines seems to have led to a barren scholasticism in physics, together with an arid instrumentalism in Ptolemaic astronomy. On the positive side, however, astronomy was liberated from commonsense realism for the conceptual experiments of Aristarchus of Samos, whose heliocentric hypothesis was not adopted by later astronomers because …


Of Manatees, Mangroves, And The Mississippi River: Is There An Estuarine Signature For The Gulf Of Mexico?, R. Eugene Turner Apr 2001

Of Manatees, Mangroves, And The Mississippi River: Is There An Estuarine Signature For The Gulf Of Mexico?, R. Eugene Turner

Faculty Publications

Important parameters of estuarine variability include morphology, flushing times, nutrient loading rates, and wetland: water ratios. This variability both reflects and disguises underlying relationships between the physics and biology of estuaries, which this comparative analysis seeks to reveal, using the Gulf of Mexico (GOM) estuaries as a starting point. A question used to focus this analysis is: are the GOM estuaries unique? The GOM receives the Mississippi River, a uniquely large, world-class river, which dominates the freshwater and nutrient inflows to the GOM continental shelf, whose margins include 35 major estuarine systems. These GOM estuaries have 28% and 41% of …


Solute Transport Through Laboratory-Scale Karstic Aquifers, Lee J. Florea, Carol M. Wicks Apr 2001

Solute Transport Through Laboratory-Scale Karstic Aquifers, Lee J. Florea, Carol M. Wicks

Lee J Florea, PhD, P.G.

Laboratory-scale models of branchwork and of network karstic aquifers were constructed to provide data needed for calibration of numerical models. The distribution and connectedness of the conduits and sinkholes were scaled similarly to those found in nature; however, the porosity of models (2 and 3%) and the recharge rate (80 cm/hr) could not be scaled appropriately. Pulses of 1-M NaCl were injected sequentially at ten locations on both models to determine transport parameters using QTRACER. For all experiments, the Reynolds numbers were <150, the Peclet numbers were >6, and the Froude numbers were ~0. The flow regime was laminar and subcritical and advective processes dominated …


Adenosine Triphosphate-Dependent Degradation Of A Fluorescent Λ N Substrate Mimic By Lon Protease, Irene Lee, Anthony J. Berdis Apr 2001

Adenosine Triphosphate-Dependent Degradation Of A Fluorescent Λ N Substrate Mimic By Lon Protease, Irene Lee, Anthony J. Berdis

Chemistry Faculty Publications

Escherichia coli Lon exhibits a varying degree of energy requirement toward hydrolysis of different substrates. Efficient degradation of protein substrates requires the binding and hydrolysis of ATP such that the intrinsic ATPase of Lon is enhanced during protein degradation. Degradation of synthetic tetrapeptides, by contrast, is achieved solely by ATP binding with concomitant inhibition of the ATPase activity. In this study, a synthetic peptide (FRETN 89-98), containing residues 89–98 of λ N protein and a fluorescence donor (anthranilamide) and quencher (3-nitrotyrosine), has been examined for ATP-dependent degradation by E. coli and human Lon proteases. The cleavage profile of FRETN 89-98 …