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2000

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Articles 1 - 30 of 2619

Full-Text Articles in Physical Sciences and Mathematics

Course In Computational Number Theory, David Bressoud, Stan Wagon Feb 2008

Course In Computational Number Theory, David Bressoud, Stan Wagon

Stan Wagon, Retired

No abstract provided.


Oczyszczanie Gazów Odlotowych Ze Spalania Odpadów Niebezpiecznych, Robert Oleniacz Dec 2000

Oczyszczanie Gazów Odlotowych Ze Spalania Odpadów Niebezpiecznych, Robert Oleniacz

Robert Oleniacz

Flue gas cleaning system is a very important part of each hazardous waste incineration plant. Air pollutant emission limit values permissible for this process in Member States of the European Union are so rigorous that the installation designers there are forced to use very effective and of course expensive solutions. In the paper a review of methods and systems used to the treatment of flue gases from hazardous waste incineration is presented. This can be particularly useful in the face of the adaptation of existing waste incineration plant operating in Poland with European Union requirements.

English title: Cleaning of flue ...


Paths In Graphs, Béla Bollobás, Amites Sarkar Dec 2000

Paths In Graphs, Béla Bollobás, Amites Sarkar

Mathematics

We prove that if 10 ≦ (k2) ≦ m < (k+12) then the number of paths of length three in a graph G of size m is at most 2m(m – k)(k - 2)/k. Equality is attained if G is the union of Kk and isolated vertices. We also give asymptotically best possible bounds for the maximal number of paths of length s, for arbitrary s, in graphs of size m. Lastly, we discuss the more general problem of maximizing the number of subgraphs isomorphic to a given graph H in graphs of size m.


Ramanujan-Like Congreuences Of The Distinct Partition Function, Ian Blumenfeld, Christi Carlstead, Mimi Cukier, Wesley Terway Dec 2000

Ramanujan-Like Congreuences Of The Distinct Partition Function, Ian Blumenfeld, Christi Carlstead, Mimi Cukier, Wesley Terway

Mathematical Sciences Technical Reports (MSTR)

In his work with the partition function, Ramanujan observed several congruences of the form p(An + B) = 0 (mod m). We adapt this form to several congruences of the distinct partition function, p2(n). We show that one can determine all ordered pairs of integers (A;B) for which p2(An + B)=0 (mod 2) and show families of congruences modulo 4. Finally, we offer a proof of a congruence modulo 5 satisfied by the distinct partition function.


Optimal Solvability For The Dirichlet And Neumann Problem In Dimension Two, Atanas Stefanov, Gregory C. Verchota Dec 2000

Optimal Solvability For The Dirichlet And Neumann Problem In Dimension Two, Atanas Stefanov, Gregory C. Verchota

Mathematics - Faculty Scholarship

We show existence and uniqueness for the solutions of the regularity and the Neumann problems for harmonic functions on Lipschitz domains with data in the Hardy spaces Hp1,(partial D)(Hp (partial D)), p>2/3-E, where D C R2 and E is a (small) number depending on the Lipschitz nature of D. This in turn implies that solutions to the Dirichlet problem with data in the Holder class C1/2+E(partial D) are themselves in C1/2+E(D). Both of these results are sharp. In fact, we prove a more general ...


Evaluation Of Striped Bass Stocks In Virginia, Monitoring And Tagging Studies, 1999-2003 Annual Report, 1 September 1999 - 31 October 2000, Philip W. Sadler, Robert E. Harris, John E. Olney, Robert J. Latour Dec 2000

Evaluation Of Striped Bass Stocks In Virginia, Monitoring And Tagging Studies, 1999-2003 Annual Report, 1 September 1999 - 31 October 2000, Philip W. Sadler, Robert E. Harris, John E. Olney, Robert J. Latour

Reports

To document continued compliance with Federal law, the Anadromous Fishes Program of the Virginia Institute of Marine Science (VIMS) has monitored the size and age composition, sex ratio and maturity schedules of the spawning striped bass stock in the Rappahannock River since December 1981 utilizing commercial pound nets and, since 1991, variable-mesh experimental gill nets. Spawning stock assessment was expanded to include the James River in 1994 utilizing 11 commercial fyke nets and variable-mesh experimental gill nets. The use of fyke nets was discontinued after 1997. In conjunction with the monitoring studies, tagging programs have been conducted in the James ...


Upper White River Bmp Implementation Project (Nps Final Report), Paul F. Vendrell, K. F. Steele, M. A. Nelson, R. W. Mcnew Dec 2000

Upper White River Bmp Implementation Project (Nps Final Report), Paul F. Vendrell, K. F. Steele, M. A. Nelson, R. W. Mcnew

Technical Reports

The project objective was to monitor agricultural best management practices implemented to minimize sediment, nutrient, and bacterial impact on water quality of the Upper White River watershed. The project targeted the primary agricultural causes of non-point source nutrient and bacterial pollution in three sub-basins of the White River in the Beaver Lake Watershed. Areas with high animal densities targeted high source areas. High source areas were treated with best management practices (BMP) in an effort to reduce the impact to the White River and Beaver Lake. The predominant BMP implemented was waste management, a component of the farm nutrient management ...


Beryllium In Granulite-Facies Pegmatites In Archean Napier Complex, Antarctica, Edward S. Grew Dec 2000

Beryllium In Granulite-Facies Pegmatites In Archean Napier Complex, Antarctica, Edward S. Grew

University of Maine Office of Research Administration: Grant Reports

This award, provided by the Office of Polar Programs of the National Science Foundation, supports participation of a researcher from the University of Maine in an expedition of the Japanese Antarctic Research Expedition (JARE) to study beryllium enriched minerals in Enderby Land. Beryllium is a rare element in crustal rocks and enrichments are especially unusual in granulite-facies (high temperature and pressure, and relatively dry conditions) metamorphic rocks. This project focuses on unique beryllium-enriched pegmatites in the Archean ultra-high temperature (up to 1000 degrees C) granulite-facies Napier Complex in eastern Casey Bay, Enderby Land, East Antarctica. The primary objective is to ...


Nonlinear Effects Of Physisorption On Static Friction, G.T. Gao, Xiao Cheng Zeng, Dennis J. Diestler Dec 2000

Nonlinear Effects Of Physisorption On Static Friction, G.T. Gao, Xiao Cheng Zeng, Dennis J. Diestler

Xiao Cheng Zeng Publications

The effects of a physisorbed film on the force of static friction in a model contact (monatomic adsorbate confined between plane-parallel walls) were investigated by Monte Carlo simulation. At fixed coverage the friction curve (shear yield stress vs normal stress) exhibits a marked nonlinearity, which results from a competition between adsorbate–wall interactions that predominate at low loads and wall–wall interactions that set in beyond a threshold load, which increases with coverage. Previous proximal-probe and computer experiments, carried out at high coverages, see only the initial (low-load) linear portion of the friction curve.


Unitarized Pseudoscalar Meson Scattering Amplitudes In Three Flavor Linear Sigma Models, Joseph Schechter, Deirdre Black, Amir H. Fariborz, Sherif Moussa, Salah Nasri Dec 2000

Unitarized Pseudoscalar Meson Scattering Amplitudes In Three Flavor Linear Sigma Models, Joseph Schechter, Deirdre Black, Amir H. Fariborz, Sherif Moussa, Salah Nasri

Physics

The three flavor linear sigma model is studied as a ``toy model'' for understanding the role of possible light scalar mesons in the \pi \pi, \pi K and \pi \eta scattering channels. The approach involves computing the tree level partial wave amplitude for each channel and unitarizing by a simple K-matrix prescription which does not introduce any new parameters. If the renormalizable version of the model is used there is only one free parameter. While this highly constrained version has the right general structure to explain \pi \pi scatteirng, it is ``not quite'' right. A reasonable fit can be made ...


Phase Diagram Of Three-Dimensional Dynamical Triangulations With A Boundary, Simon Catterall, Simeon Warner, Ray Renken Dec 2000

Phase Diagram Of Three-Dimensional Dynamical Triangulations With A Boundary, Simon Catterall, Simeon Warner, Ray Renken

Physics

We use Monte Carlo simulation to study the phase diagram of three-dimensional dynamical triangulations with a boundary. Three phases are indentified and characterized. One of these phases is a new, boundary dominated phase; a simple argument is presented to explain its existence. First-order transitions are shown to occur along the critical lines separating phases.


Optically Induced Periodic Structures In Smectic-C Liquid Crystals, Antal Jákli, A. Vajda, E. Benkler, Janossy, Peter Palffy-Muhoray Dec 2000

Optically Induced Periodic Structures In Smectic-C Liquid Crystals, Antal Jákli, A. Vajda, E. Benkler, Janossy, Peter Palffy-Muhoray

Antal Jakli

We explore periodic structures of smectic-C (SmC) liquid crystals, induced optically by a polarization grating. The studied cells contain a passive surface of rubbed polyimide and an active photosensitive substrate of ate-dye doped polyimide. In a nematic phase the director field can be periodic independent of the angle between the grating vector and the rubbing direction. In the SmA phase periodic structure can be induced only by layer undulations. The SmC behaves similarly to the nematic phase, but the director can rotate only on a cone, which results in a more complex geometry. The periodic pattern is superimposed with four ...


Constant Mean Curvature Surfaces With Three Ends, Karsten Grosse-Brauckmann, Robert Kusner, John M. Sullivan Dec 2000

Constant Mean Curvature Surfaces With Three Ends, Karsten Grosse-Brauckmann, Robert Kusner, John M. Sullivan

Robert Kusner

We announce the classification of complete almost embedded surfaces of constant mean curvature, with three ends and genus zero. They are classified by triples of points on the sphere whose distances are the asymptotic necksizes of the three ends.


Water Quality Conference 2001, Richard W. Larson Dec 2000

Water Quality Conference 2001, Richard W. Larson

Integrated Crop Management News

Plan to attend the 2001 Water Quality Conference "Agriculture and the Environment: State and Federal Initiatives" on March 5-7. The conference will address federal and state nonpoint source pollution policies that could potentially impact land management in agricultural watersheds. Topics will address both programs and current research for total maximum daily loads, nutrient loading and nutrient criteria, animal feeding operations, and source water protection. The conference will be held at the Scheman Building, Iowa State University, Ames, from 9:45 a.m. to 5:00 p.m. on March 5, from 8:30 a.m. to 5:00 p.m ...


Phosphorus In Aquatic Systems, John A. Downing, John A. Downing, Antonio P. Mallarino, John E. Sawyer, John Creswell, Michael J. Tidman Dec 2000

Phosphorus In Aquatic Systems, John A. Downing, John A. Downing, Antonio P. Mallarino, John E. Sawyer, John Creswell, Michael J. Tidman

Integrated Crop Management News

This article continues a series that provides producers with information to aid in phosphorus (P) management and to understand environmental issues relating to P management. It focuses on P in aquatic systems (wetlands, streams, rivers, and lakes) and its impact on surface water quality.


Higher Twist Contributions To R-Hadron Phenomenology In The Light Gluino Scenario, Thomas D. Gutierrez, R. Vogt, J. F. Gunion Dec 2000

Higher Twist Contributions To R-Hadron Phenomenology In The Light Gluino Scenario, Thomas D. Gutierrez, R. Vogt, J. F. Gunion

Physics

The open light gluino window allows non-trivial higher-twist gluino contributions to the proton wave function. Using a two-component model originally developed for charm hadroproduction, higher-twist intrinsic gluino contributions to final-state R-hadron formation are shown to enhance leading-twist production in the forward xnF region. We calculate R-hadron production at Pnlab=800 GeV in pp, pBe, and pCu interactions with light gluino masses of 1.2, 1.5, 3.5, and 5.0 GeV.


Chemical And Dynamical Speciation Of Mobile Ions In The Glassy Fast Ionic Conductor Ag2s+B2s3+Sis2: A 109ag Nuclear Magnetic Resonance Study, Tomoko Akai, Steve W. Martin, Ferdinando Borsa Dec 2000

Chemical And Dynamical Speciation Of Mobile Ions In The Glassy Fast Ionic Conductor Ag2s+B2s3+Sis2: A 109ag Nuclear Magnetic Resonance Study, Tomoko Akai, Steve W. Martin, Ferdinando Borsa

Materials Science and Engineering Publications

109Ag NMR in the highly conductive glass 0.525Ag2S+0.475(0.5B2S3+0.5SiS2) was investigated from 230 to 433 K. The 109Ag NMR spectra reveal for the first time three well resolved lines corresponding to three kinds of chemically speciated Ag ions in sites with different chemical shifts in a macroscopically homogeneous glass. This chemical speciation of Ag ions is discussed in relation to the microstructure of the glass. As the temperature is increased, the three lines that originate from three different species of ions are narrowed, but these lines exist independently up to 433 K, the highest ...


The Savannah River Site: Site Description, Land Use And Management History, David L. White, Karen F. Gaines Dec 2000

The Savannah River Site: Site Description, Land Use And Management History, David L. White, Karen F. Gaines

Publications

The 78,000-ha Savannah River Site, which is located in the upper Coastal Plain of South Carolina along the Savannah River, was established as a nuclear production facility in 1951 by the Atomic Energy Commission. The site’s physical and vegetative characteristics, land use history, and the impacts of management and operations are described. Aboriginal and early European settlement was primarily along streams, where much of the farming and timber cutting have occurred. Woodland grazing occurred in the uplands and lowlands. Land use intensity increased after the Civil War and peaked in the 1920s. Impacts from production of cotton and ...


An Evaluation Of Stream Flow Characteristics And Fecal Coliform Loads In Sayler's Creek Watershed, South Central Virginia, David Straton Gilbert Dec 2000

An Evaluation Of Stream Flow Characteristics And Fecal Coliform Loads In Sayler's Creek Watershed, South Central Virginia, David Straton Gilbert

Theses, Dissertations & Honors Papers

The Sayler's Creek watershed is located within Prince Edward County, Nottoway, and Amelia Counties of the south central region of Virginia. The Sayler's Creek Watershed consists of two small creeks: Big Sayler's Creek and Little Sayler's Creek. The Environmental Protection Agency has Big Sayler's Creek listed as impaired and not Little Sayler's Creek. Based upon visual inspections of the Sayler's Creek watershed throughout the year, Little Sayler's Creek is inlpaired for fecal coliform instead of Big Sayler's Creek. Another hypothesis of this study is that fecal coliform levels are directly related ...


Electrons In Image States Near Roughened Metal Surfaces, Brian K. Clark, Brian W. Gregory, Jean M. Standard Dec 2000

Electrons In Image States Near Roughened Metal Surfaces, Brian K. Clark, Brian W. Gregory, Jean M. Standard

Faculty Publications – Chemistry

Electrons near roughened Ag and Au surfaces with chemisorbed dielectric overlayers of alkanethiol or alkaneselenol self-assembled monolayers are shown to move within the sulfur or selenium head-group layer on the metal terraces. The electrons exist in image states with respect to Ag or Au step edges. There is no substantial image force between the electrons and the terraces.


A Two-Chain Path Integral Model Of Positronium, L. Larrimore, R. N. Mcfarland, P. A. Sterne, Amy Lisa Graves Dec 2000

A Two-Chain Path Integral Model Of Positronium, L. Larrimore, R. N. Mcfarland, P. A. Sterne, Amy Lisa Graves

Physics & Astronomy Faculty Works

We have used a path integral Monte Carlo technique to simulate positronium (Ps) in a cavity. The primitive propagator is used, with a pair of interacting chains representing the positron and electron. We calculate the energy and radial distribution function for Ps enclosed in a hard, spherical cavity, and the polarizability of the model Ps in the presence of an electrostatic field. We find that the positron distribution near the hard wall differs significantly from that for a single particle in a hard cavity. This leads to systematic deviations from predictions of free-volume models which treat Ps as an effective ...


Temporal Changes In The Observed Relationship Between Cloud Cover And Surface Air Temperature, Bomin Sun, Pavel Ya. Groisman, Raymond S. Bradley, Frank T. Keimig Dec 2000

Temporal Changes In The Observed Relationship Between Cloud Cover And Surface Air Temperature, Bomin Sun, Pavel Ya. Groisman, Raymond S. Bradley, Frank T. Keimig

Raymond S Bradley

The relationship between cloud cover and near-surface air temperature and its decadal changes are examined using the hourly synoptic data for the past four to six decades from five regions of the Northern Hemisphere: Canada, the United States, the former Soviet Union, China, and tropical islands of the western Pacific. The authors define the normalized cloud cover–surface air temperature relationship, NOCET or dT/dCL, as a temperature anomaly with a unit (one-tenth) deviation of total cloud cover from its average value. Then mean monthly NOCET time series (night- and daytime, separately) are area-averaged and parameterized as functions of surface ...


Detection Of Variable Frequency Signals Using A Fast Chirp Transform, F. A. Jenet, T. A. Prince Dec 2000

Detection Of Variable Frequency Signals Using A Fast Chirp Transform, F. A. Jenet, T. A. Prince

Physics and Astronomy Faculty Publications and Presentations

The detection of signals with varying frequency is important in many areas of physics and astrophysics. The current work was motivated by a desire to detect gravitational waves from the binary inspirai of neutron stars and black holes, a topic of significant interest for the new generation of interferometric gravitational wave detectors such as LIGO. However, this work has significant generality beyond gravitational wave signal detection. We define a fast chirp transform (FCT) analogous to the fast Fourier transform. Use of the FCT provides a simple and powerful formalism for detection of signals with variable frequency just as Fourier transform ...


Fractional Derivatives, John M. Beach Dec 2000

Fractional Derivatives, John M. Beach

Theses and Dissertations

In this thesis, the reader will not find a study of any kind; there is no methodology, questionnaire, interview, test, or data analysis. This thesis is simply a research paper on fractional derivatives, a topic that I have found to be fascinating. The reader should be delighted by a short history of the topic in Chapter 1, where he/she will read about the contributions made by some of the great mathematicians from the last three centuries.

In Chapter 2 the reader will find an intuitive approach for finding the general fractional derivative for functions such as eax, x ...


Powre: High-Resolution Chronology Of Millennial-Scale Lake-Level Fluctuations In The Dry Valleys (Antarctica) From Uranium-Thorium And Radiocarbon Dating, Brenda L. Hall Dec 2000

Powre: High-Resolution Chronology Of Millennial-Scale Lake-Level Fluctuations In The Dry Valleys (Antarctica) From Uranium-Thorium And Radiocarbon Dating, Brenda L. Hall

University of Maine Office of Research Administration: Grant Reports

The Professional Opportunities for Women in Research and Engineering (POWRE) program affords new research and educational enhancement opportunities for women scientists. This project, which addresses the fundamental problem of the cause of millennial-scale climate change, contains components specifically designed to increase the educational and research skills of the principal investigator. She will learn the following new information/skills: 1) thermal ionization mass spectrometry (TIMS) uranium/thorium (U/TH) dating with Dr. G. Henderson at Lamont-Doherty Earth Observatory (LDEO) and Oxford University, 2) millennial-scale climate change with Drs. W. Broecker and G. Bond, LDEO, and with Drs. D. Oppo and L ...


Master Equation For Hydrogen Recombination On Grain Surfaces, Gianfranco Vidali, Ofer Biham, Itay Furman, Valerio Pirronello Dec 2000

Master Equation For Hydrogen Recombination On Grain Surfaces, Gianfranco Vidali, Ofer Biham, Itay Furman, Valerio Pirronello

Physics

Recent experimental results on the formation of molecular hydrogen on astrophysically relevant surfaces under conditions similar to those encountered in the interstellar medium provided useful quantitative information about these processes. Rate equation analysis of experiments on olivine and amorphous carbon surfaces provided the activation energy barriers for the diffusion and desorption processes relevant to hydrogen recombination on these surfaces. However, the suitability of rate equations for the simulation of hydrogen recombination on interstellar grains, where there might be very few atoms on a grain at any given time, has been questioned. To resolve this problem, we introduce a master equation ...


The Dynamics And Significance Of Carbon Monoxide Exchanges Between Wetlands And The Atmosphere, Gary M. King Dec 2000

The Dynamics And Significance Of Carbon Monoxide Exchanges Between Wetlands And The Atmosphere, Gary M. King

University of Maine Office of Research Administration: Grant Reports

Carbon monoxide (CO) plays a major role in atmospheric chemistry. Through a series of reactions, CO can contribute to the formation of tropospheric ozone, which poses a serious health concern on a regional scale. While anthropogenic sources of CO are reasonably well understood, relatively little is known about natural CO sources and sinks. Wetlands have been discounted as CO sources on the basis of sediment CO concentrations. However, plant leaves and stems produce significant amounts of CO when illuminated by the sun. Because of their large amounts of plant biomass, wetlands are likely strong net CO sources. Our work will ...


Cross Section For B-Jet Production In P̅P Collisions At √S = 1.8 Tev, B. Abbott, Gregory R. Snow, D0 Collaboration Dec 2000

Cross Section For B-Jet Production In P̅P Collisions At √S = 1.8 Tev, B. Abbott, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

Bottom-quark production in p̅p collisions at √s = 1.8 TeV is studied with 5 pb-1 of data collected in 1995 by the D0 detector at the Fermilab Tevatron Collider. The differential production cross section for b jets in the central rapidity region (∣yb∣< 1) as a function of jet transverse energy is extracted from a muon-tagged jet sample. Within experimental and theoretical uncertainties, D0 results are found to be higher than, but compatible with, next-to-leading-order QCD predictions.


Effects Of Temperature Anomalies On The Palmer Drought Severity Index In The Central United States, Q. Steven Hu, Garry D. Wilson Dec 2000

Effects Of Temperature Anomalies On The Palmer Drought Severity Index In The Central United States, Q. Steven Hu, Garry D. Wilson

Papers in Natural Resources

The purpose of this study is to improve our understanding of temperature and precipitation effects on the Palmer Drought Severity Index (PDSI). Both theoretical and observational analyses were applied to separate and compare temperature and precipitation effects on PDSI. The results showed that because of the dependence of PDSI on the ‘climatologically appropriate rainfall’, which is a function of time and varies with surface air temperature, the PDSI can be equally affected by temperature and precipitation, when both have similar magnitudes of anomalies. Calculations using observational data further illustrated the temperature influence on PDSI in different climate regions in the ...


Comparisons Of Gravity Anomalies At Pseudofaults, Fracture Zones, And Nontransform Discontinuities From Fast To Slow Spreading Areas, Sarah E. Kruse, Sarah F. Tebbens, David F. Naar, Qingyuan Y. Lou, Robert T. Bird Dec 2000

Comparisons Of Gravity Anomalies At Pseudofaults, Fracture Zones, And Nontransform Discontinuities From Fast To Slow Spreading Areas, Sarah E. Kruse, Sarah F. Tebbens, David F. Naar, Qingyuan Y. Lou, Robert T. Bird

Geology Faculty Publications

Published mechanisms for rift tip propagation at spreading centers include extensional deformation and an initial period of slow spreading. We investigate whether the gravity signal and inferred crustal structure at pseudofaults formed in medium to superfast spreading environments resemble the gravity signal at fracture zones or nontransform discontinuities formed in slow spreading environments. We find that altimetry-based gravity anomalies on the Mathematician, Bauer, Easter, Juan Fernandez, and northern Chile Ridge pseudofaults, located in 75–150 mm/yr (full rate) seafloor spreading environments, are similar in amplitude and form to Atlantic fracture zones with 20–30 mm/yr spreading rates. A ...