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 1 - 30 of 2685

Full-Text Articles in Physical Sciences and Mathematics

Seasonal Migration Of Columbia Spotted Frogs (Rana Luteiventris) Among Complementary Resources In A High Mountain Basin, David S. Pilliod, Charles R. Peterson, Peter I. Ritson Dec 2001

Seasonal Migration Of Columbia Spotted Frogs (Rana Luteiventris) Among Complementary Resources In A High Mountain Basin, David S. Pilliod, Charles R. Peterson, Peter I. Ritson

USGS Staff -- Published Research

Information on how animals partition their activities and travel among complementary resources, such as breeding or overwintering habitats, is needed for species conservation. In a mountain basin at 2500 m elevation in central Idaho, we studied the habitat use and movement patterns of 736 marked and 87 radio-tagged Columbia spotted frogs (Rana luteiventris) from 1995 to 1998. The goals of this study were to (i) identify and characterize R. luteiventris breeding, summer foraging, and overwintering habitats, (ii) describe the movement patterns of juvenile, male, and female R. luteiventris among these resources, and (iii) detennine migration routes. Juvenile and adult R ...


Ocena Składu Gazów Odlotowych Z Procesów Spopielania Odpadów Niebezpiecznych Pod Kątem Trudności Oczyszczania I Toksyczności, Robert Oleniacz Dec 2001

Ocena Składu Gazów Odlotowych Z Procesów Spopielania Odpadów Niebezpiecznych Pod Kątem Trudności Oczyszczania I Toksyczności, Robert Oleniacz

Robert Oleniacz

Tightening of the European Union law in the field of the air emission limit values from waste incineration causes necessity for existing and new incineration plants to conform to the standards. It will often involve modernization of the flue gas cleaning system. Proposed in the paper the methodology of evaluation of the combustion gases composition in point of view cleaning difficulty should be useful to this end. Average toxicity factors for hazardous waste incineration flue gases were defined as well. Among other things they can be used in comparative analysis of the air pollutant concentration in the raw gas (before ...


Modeling Hydrogen Diffusion For Solar Cell Passivation And Process Optimization, Yi Zhang Dec 2001

Modeling Hydrogen Diffusion For Solar Cell Passivation And Process Optimization, Yi Zhang

Dissertations

A diffusion model for hydrogen (H) in crystalline silicon was established which takes into account the charged state conversion, junction field, mobile traps, and complex formation and dissociation at dopant and trap sites. Carrier exchange among the various charged species is a "fast" process compared to the diffusion process. A numerical method was developed to solve the densities of various charged species from the Poisson's equation that involves shallow-level dopants and one "negative U" impurity, e.g., H. Time domain implicit method was adopted in finite difference scheme to solve the fully coupled equations.

Limiting versions of the model ...


Simultaneous Removal Of Ortho-Dichlorobenzene And Ethanol Vapors In A Biotrickling Filter : Experimental Results And Process Modeling, Suchismita Bhattacharya Dec 2001

Simultaneous Removal Of Ortho-Dichlorobenzene And Ethanol Vapors In A Biotrickling Filter : Experimental Results And Process Modeling, Suchismita Bhattacharya

Dissertations

This study investigated the possibility of simultaneous removal of vapors of dissimilar volatile organic compounds from air streams in a biotrickling filter (BTF). Using a rricrobial consortium known to utilize ortho-dichlorobenzene (o-DCB) as sole carbon and energy source, a culture was developed on o-DCB/ethanol mixtures and a BTF unit was developed and operated with air streams carrying o-DCB and ethanol vapors. Simultaneous removal of the two compounds was observed in experiments that span a period of over three years.

Experiments were performed at air residence times ranging from 4 to 6.5 min, liquid flow rates from 3.6 ...


Development Of Analytical Systems And Monitoring Of Vocs Emissions During Polymer Processing, Qin Xiang Dec 2001

Development Of Analytical Systems And Monitoring Of Vocs Emissions During Polymer Processing, Qin Xiang

Dissertations

A method using direct flame ionization detector (FID) measurement was developed to study total volatile organic compounds (VOCs) emissions during thermal degradation of polymers. This was used to estimate organic emissions from both virgin polymer resins and commingled plastics. The effects of process parameters, i. e., temperature, heating rate and residence time, were also studied. Significant VOCs emissions were observed at normal processing temperatures, particularly from recycled polymers. Each polymer showed a distinct evolution pattern during its thermal degradation. Kinetics of VOCs emissions were also studied using a non-isothermal technique. The kinetic parameters were in agreement with data from the ...


University Of Nevada, Las Vegas Advanced Accelerator Applications University Participation Program: Quarterly Report, Third Quarter (September To November 2001), Anthony Hechanova Dec 2001

University Of Nevada, Las Vegas Advanced Accelerator Applications University Participation Program: Quarterly Report, Third Quarter (September To November 2001), Anthony Hechanova

Transmutation Research Program Reports (TRP)

This Quarterly Report is a primary deliverable from the University of Nevada, Las Vegas (UNLV) Advanced Accelerator Applications (AAA) University Participation Program (UPP) Director to the U.S. Department of Energy (DOE) as described in the UNLV AAA proposal and Statement of Work for the Third Quarter.

The UNLV AAA UPP Director implements the program’s administration using staff from the Harry Reid Center for Environmental Studies (HRC) to ensure that work conducted under the UNLV AAA UPP meets program objectives. The UNLV AAA UPP consists of three components: Program Support, Research Infrastructure Augmentation, and Student Research.


Detectability Of Excitatory Vs. Inhibitory Drive In A Thalamocortical Relay Neuron Model., Gregory D. Smith, S Murray Sherman Dec 2001

Detectability Of Excitatory Vs. Inhibitory Drive In A Thalamocortical Relay Neuron Model., Gregory D. Smith, S Murray Sherman

Applied Science Faculty and Graduate Publications

Although inhibitory inputs are often viewed as equal but opposite to excitatory inputs, excitatory inputs may alter the firing of postsynaptic cells more effectively than inhibitory inputs. This is because spike cancellation produced by an inhibitory input requires coincidence in time, whereas an excitatory input can add spikes with less temporal constraint. To test for such potential differences, especially in the context of the function of thalamocortical (TC) relay nuclei, we used a stochastic “integrate-and-fire-or-burst” TC neuron model to quantify the detectability of excitatory and inhibitory drive in the presence and absence of the low-threshold ...


The Siting Of Regional Sanitary Landfills Or Facilities For Municipal Solid Waste In The Upper Southern Region Of Thailand, Jantira Duangsai Dec 2001

The Siting Of Regional Sanitary Landfills Or Facilities For Municipal Solid Waste In The Upper Southern Region Of Thailand, Jantira Duangsai

Theses

The pollution problem from municipal solid waste in Thailand is serious. Population growth and rapid economic expansion have resulted in a significant increase in the quantity of solid waste. Inadequate provisions for waste collection, shortages of disposal equipment, and the inability of the responsible agencies to find appropriate disposal sites, also are major causes of the present problems. The environmental impacts that result from unsanitary disposal sites have become a serious public concern across the country.

Environmentally protective and publicly acceptable siting of regional sanitary landfills or facilities for municipal solid waste management in the upper southern region of Thailand ...


Comparative Molecular Field Analysis (Comfa) Of Protonated Methylphenidate Phenyl-Substituted Analogs, Kathleen Mary Gilbert Dec 2001

Comparative Molecular Field Analysis (Comfa) Of Protonated Methylphenidate Phenyl-Substituted Analogs, Kathleen Mary Gilbert

Theses

Protonated methylphenidate (pMP) and several phenyl-substituted pMP analogs were analyzed using Comparative Molecular Field Analysis (CoMFA) to develop a pharmacophore for dopamine transporter (DAT) binding. This research is a part of an interdisciplinary study on using methylphenidate (MP) analogs to block the binding of cocaine to the DAT as a treatment for addiction.

A random search conformational analysis using key pMP torsional angles was performed to create conformer families representing possible bioactive conformations. The lowest energy pMP conformer of each family was used as a template to create phenyl-substituted pMP analogs.

Partial least squares analysis was used to determine the ...


Short-Term Community Based Dune Management Activities On A Highly Developed Coast In New Jersey, Stacy Mccormack Dec 2001

Short-Term Community Based Dune Management Activities On A Highly Developed Coast In New Jersey, Stacy Mccormack

Theses

Recently, local governments have started to realize the effectiveness of dune building as a form of hazard mitigation and have engineered dunes for this purpose. This study evaluates dune management at the local level; specifically, short term management practices, physical constraints, dune management participants, and sources of guidance. A review of municipal regulations, topographic surveys, and interviews with local officials were conducted in four New Jersey communities: Belmar, Spring Lake, Sea Girt and Manasquan. The results of this study indicate that dunes were established as part of local hazard mitigation planning in response to the 1992 storm, and topographic surveys ...


A Tool For Phylogenetic Data Cleaning And Searching, Viswanath Neelavalli Dec 2001

A Tool For Phylogenetic Data Cleaning And Searching, Viswanath Neelavalli

Theses

Data collection and cleaning is a very important part of an elaborate Data Mining System. 'TreeBASE' is a relational database of phylogenetic information at the Harvard University with a keyword based searching interface. 'TreeSearch' is a Structure based search engine implemented at NJIT that can be used for searching phylogenetic data. Phylogenetic trees are extracted from the flat-file database at Harvard University, available at {ftp://herbaria.harvard.edu/pub/piel/Data/files/}. There is huge amount of information present in the files about the trees and the data matrices from which the trees are generated. The search tool implemented at ...


A Review And Assessment Of Novice Learning Tools For Problem Solving And Program Development, Christopher John Bladek Dec 2001

A Review And Assessment Of Novice Learning Tools For Problem Solving And Program Development, Christopher John Bladek

Theses

There is a great demand for the development of novice learning tools to supplement classroom instruction in the areas of problem solving and program development. Research in the area of pedagogy, the psychology of programming, human-computer interaction, and cognition have provided valuable input to the development of new methodologies, paradigms, programming languages, and novice learning tools to answer this demand.

Based on the cognitive needs of novices, it is possible to postulate a set of characteristics that should comprise the components an effective novice-learning tool. This thesis will discover these characteristics and provide recommendations for the development of new learning ...


A New Theory Of Premixed Flames In Near-Stoichiometric Mixtures, Eliana S. Antoniou Dec 2001

A New Theory Of Premixed Flames In Near-Stoichiometric Mixtures, Eliana S. Antoniou

Dissertations

In this dissertation, a new model of premixed flames in near-stoichiometric mixtures is derived. Unlike most previous theories, which are valid only for very lean or very rich, i.e. off-stoichiometric conditions, our model remains valid over the entire spectrum of mixture compositions, from lean to rich, including the near-stoichiometric regime. Since fuel-mixture composition is known to have a significant effect on flame behavior, such a model is expected to contribute new insights into classical problems in premixed combustion.

In the first part of this dissertation, we describe the derivation of a model for premixed flames in two-reactant mixtures in ...


Spherical Diffusion, Thomas Bülow Dec 2001

Spherical Diffusion, Thomas Bülow

Technical Reports (CIS)

Data defined on spherical domains occurs in various applications, such as surface modeling, omnidirectional imaging, and the analysis of keypoints in volumetric data. The theory of spherical signals lacks important concepts like the Gaussian function, which is permanently used in planar image processing. We propose a definition of a spherical Gaussian function as the Green's function of the spherical diffusion process. This allows to introduce a linear scale space on the sphere. We apply this new filter to the smoothing of 3D object surfaces.


Quantification Of Plasma And Egg 4,4′ Dinitrocarbanilide (Dnc) Residues For The Efficient Development Of A Nicarbazin-Based Contraceptive For Pest Waterfowl, John J. Johnston, Walter M. Britton, Alexander Macdonald, Thomas M. Primus, Margaret J. Goodall, Christi A. Yoder, Lowell A. Miller, Kathleen A. Fagerstone Dec 2001

Quantification Of Plasma And Egg 4,4′ Dinitrocarbanilide (Dnc) Residues For The Efficient Development Of A Nicarbazin-Based Contraceptive For Pest Waterfowl, John J. Johnston, Walter M. Britton, Alexander Macdonald, Thomas M. Primus, Margaret J. Goodall, Christi A. Yoder, Lowell A. Miller, Kathleen A. Fagerstone

USDA National Wildlife Research Center - Staff Publications

Urbanization and associated landscaping has increased the abundance of year-round habitat for waterfowl, resulting in vegetation damage, loss of recreational activities, air transportation mishaps and health hazards. As part of a research program to develop socially acceptable techniques for management of pest bird populations, we are evaluating nicarbazin as a contraceptive in pest and surrogate avian species. As reproductive studies with Canada Geese (Branta canadensis) are tedious due to the difficulty of conducting controlled field studies and/or breeding geese in captivity, we evaluated the effects of oral nicarbazin administration on the production and hatchability of chicken studies are being ...


Scroll Waves In The Presence Of Slowly Varying Anisotropy With Application To The Heart, S. Setayeshgar, Andrew J. Bernoff Dec 2001

Scroll Waves In The Presence Of Slowly Varying Anisotropy With Application To The Heart, S. Setayeshgar, Andrew J. Bernoff

All HMC Faculty Publications and Research

We consider the dynamics of scroll waves in the presence of rotating anisotropy, a model of the left ventricle of the heart in which the orientation of fibers in successive layers of tissue rotates. By choosing a coordinate system aligned with the fiber rotation and studying the phase dynamics of a straight but twisted scroll wave, we derive a Burgers’ equation with forcing associated with the fiber rotation rate. We present asymptotic solutions for scroll twist, verified by numerics, using a realistic fiber distribution profile. We make connection with earlier numerical and analytical work on scroll dynamics.


Open Source Software: A History, David Bretthauer Dec 2001

Open Source Software: A History, David Bretthauer

Published Works

In the 30 years from 1970-2000, open source software began as an assumption without a name or a clear alternative. It has evolved into a sophisticated movement which has produced some of the most stable and widely used software packages ever produced. This paper traces the evolution of three operating systems: GNU, BSD, and Linux, as well as the communities which have evolved with these systems and some of the commonly-used software packages developed using the open source model. It also discusses some of the major figures in open source software, and defines both “free software” and “open source software.”


Thin Polyimide Films Prepared By Ionic Self-Assembly, Mark Anderson, Richey Davis, C. Douglas Taylor, Michiaiah Parker, Spencer Clark, Daniela Marciu, Michael Miller Dec 2001

Thin Polyimide Films Prepared By Ionic Self-Assembly, Mark Anderson, Richey Davis, C. Douglas Taylor, Michiaiah Parker, Spencer Clark, Daniela Marciu, Michael Miller

Mark R. Anderson

Layer-by-layer electrostatic deposition of polyelectrolytes was used to modify a gold substrate with polydiallyl dimethylammonium chloride and an Ultem-type poly(amic acid) salt. Following deposition, heat treatment converted the poly(amic acid) salt into a polyimide. A decrease in the thin film thickness and a substantial increase in the interfacial contact angle accompanied thermal treatment. Results from cyclic voltammetry measurements also show that the imidized surface had a decreased dielectric constant relative to an unmodified or a poly(amic acid)-modified interface. Each of these results is consistent with formation of the polyimide. Infrared spectra of the thin films formed ...


Water Quality Conference 2002, Richard W. Larson Dec 2001

Water Quality Conference 2002, Richard W. Larson

Integrated Crop Management News

Plan to attend the 2002 Water Quality Conference "Agriculture and the Environment: The Challenge of Change" on March 4-6. This conference will provide a forum for awareness and discussion of critical issues affecting water resources in Iowa. Topic presentations and panel discussions will address how Iowa agriculture is changing and the impact of change on Iowa's water resources. 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 4; from 8:30 a.m. to 4:30 p.m. on March 5; and from ...


The Minimal Model Of Nonbaryonic Dark Matter: A Singlet Scalar, C Burgess, M Pospelov, Tonnis Ter Veldhuis Dec 2001

The Minimal Model Of Nonbaryonic Dark Matter: A Singlet Scalar, C Burgess, M Pospelov, Tonnis Ter Veldhuis

Tonnis ter Veldhuis

No abstract provided.


Radiation Transport Modeling Of Beam-Target Experiments For The Aaa Project: Quaterly Report, William Culbreth Dec 2001

Radiation Transport Modeling Of Beam-Target Experiments For The Aaa Project: Quaterly Report, William Culbreth

Reactor Campaign (TRP)

The national development of technology to transmute nuclear waste depends upon the generation of high energy neutrons produced by proton spallation. Proton accelerators, such as LANSCE at the Los Alamos National Laboratory, are capable of producing 800 MeV protons. By bombarding a lead/bismuth target, each proton may generate 500 or more neutrons that can activate fission products or induce the fission of transuranic isotopes.

The Monte Carlo radiation transport code MCNPX developed at LANL is an important tool in the design of transmuter technology. It must be validated, however, for the neutron energy that will be employed. Experiments are ...


Nuclear Criticality Analyses Of Separations Processes For The Transmutation Fuel Cycle: Quaterly Report, William Culbreth, Pang Tao Dec 2001

Nuclear Criticality Analyses Of Separations Processes For The Transmutation Fuel Cycle: Quaterly Report, William Culbreth, Pang Tao

Separations Campaign (TRP)

During the first quarter of the work, the tasks included training students in the use of Monte Carlo codes used in radiation transport studies and the assessment of neutron multiplication factors for specific problems outlined by ANL-East through Drs. Laidler and Vandegrift.

The proposal also included objectives for the first year of work on this project, as listed below. The work conducted in the first quarter of the project was in partial completion of these objectives.

• Train UNLV students in the use of SCALE and/or MCNP for the assessment of nuclear criticality.

• Assess neutron multiplication factor, keff, for ...


“[Cu(Pyrazine-2-Carboxylate)2]2Cd4I8: Unprecedented 1-D Serpentine Chains And Regular 2-D Regular Metal-Organic Square Grids In A 3-D Framework., Delia M. Ciurtin, Mark D. Smith, Hans Conrad Zur Loye Dec 2001

“[Cu(Pyrazine-2-Carboxylate)2]2Cd4I8: Unprecedented 1-D Serpentine Chains And Regular 2-D Regular Metal-Organic Square Grids In A 3-D Framework., Delia M. Ciurtin, Mark D. Smith, Hans Conrad Zur Loye

Faculty Publications

A novel three-dimensional coordination polymer containing
an unprecedented one-dimensional serpentine motif conjoined
with a two-dimensional square grid motif is presented.


Measuring The Speed Of Sound Of Quintessence, Christian Armendariz-Picon, Joel K. Erickson, R. R. Caldwell, Paul J. Steinhardt, V. Mukhanov Dec 2001

Measuring The Speed Of Sound Of Quintessence, Christian Armendariz-Picon, Joel K. Erickson, R. R. Caldwell, Paul J. Steinhardt, V. Mukhanov

Physics

Quintessence, a time-varying energy component that may account for the accelerated expansion of the universe, can be characterized by its equation of state and sound speed. In this paper, we show that if the quintessence density is at least one percent of the critical density at the surface of last scattering the cosmic microwave background anisotropy can distinguish between models whose sound speed is near the speed of light versus near zero, which could be useful in distinguishing competing candidates for dark energy.


Method Of Solubilizing Shortened Single-Walled Carbon Nanotubes In Organic Solutions, Robert C. Haddon, Jian Chen Dec 2001

Method Of Solubilizing Shortened Single-Walled Carbon Nanotubes In Organic Solutions, Robert C. Haddon, Jian Chen

Chemistry Faculty Patents

Naked single-walled nanotube carbon metals and semiconductors were dissolved in organic solutions by derivatization with SOCl2 and octadecylamine charge. Both ionic (charge transfer) and covalent solution phase chemistry with concomitant modulation of the single-walled carbon nanotubes (SWNT) band structure were demonstrated. Solution phase near-IR spectroscopy was used to study the effects of chemical modifications on the band gaps of the SWNTs. Reaction of solubilized SWNTs with dichlorocarbene led to functionalization of the nanotube walls.


Teco: Carbon Monoxide Consumption By Forest And Agroecosystem Soils, Gary M. King Dec 2001

Teco: Carbon Monoxide Consumption By Forest And Agroecosystem Soils, Gary M. King

University of Maine Office of Research Administration: Grant Reports

Carbon monoxide is a more dynamic component of the atmosphere than methane, occurring at a lower concentration but substantially higher flux. CO and hydroxyl radical interact rapidly, affecting a number of atmospheric parameters: the oxidative state of the troposphere; the fate and residence times of methane, non-methane organics and inorganics; tropospheric ozone; and the extent of thermal forcing. Soils consume atmospheric CO, accounting for 10-25% of the global carbon budget, depending on the source estimate. Some of the controls of soil CO uptake and production have been described generally, but much remains unknown. Details of CO uptake in agroecosystems are ...


Development Of Cfl-Free, Explicit Schemes For Multidimensional Advection-Reaction Equations, Hong Wang, Jiangguo Liu Dec 2001

Development Of Cfl-Free, Explicit Schemes For Multidimensional Advection-Reaction Equations, Hong Wang, Jiangguo Liu

Faculty Publications

We combine an Eulerian–Lagrangian approach and multiresolution analysis to develop unconditionally stable, explicit, multilevel methods for multidimensional linear hyperbolic equations. The derived schemes generate accurate numerical solutions even if large time steps are used. Furthermore, these schemes have the capability of carrying out adaptive compression without introducing mass balance error. Computational results are presented to show the strong potential of the numerical methods developed.


Ratio Of Isolated Photon Cross Sections In Pp̅ Collisions At √S = 630 And 1800 Gev, V. M. Abazov, Gregory R. Snow, D0 Collaboration Dec 2001

Ratio Of Isolated Photon Cross Sections In Pp̅ Collisions At √S = 630 And 1800 Gev, V. M. Abazov, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

The inclusive cross section for production of isolated photons has been measured in pp̅ collisions at √s = 630 GeV with the D0 detector at the Fermilab Tevatron Collider. The photons span a transverse energy (ET) range from 7–49 GeV and have pseudorapidity∣η∣ < 2.5. This measurement is combined with the previous D0 result at √s = 1800 GeV to form a ratio of the cross sections. Comparison of next-to-leading-order QCD with the measured cross section at 630 GeV and the ratio of cross sections show satisfactory agreement in most of the ET range.


Testing A Fourier Accelerated Hybrid Monte Carlo Algorithm, Simon Catterall, Sergey Karamov Dec 2001

Testing A Fourier Accelerated Hybrid Monte Carlo Algorithm, Simon Catterall, Sergey Karamov

Physics

We describe a Fourier Accelerated Hybrid Monte Carlo algorithm suitable for dynamical fermion simulations of non-gauge models. We test the algorithm in supersymmetric quantum mechanics viewed as a one-dimensional Euclidean lattice field theory. We find dramatic reductions in the autocorrelation time of the algorithm in comparison to standard HMC.


Search For Gluinos And Squarks Using Like-Sign Dileptons In Pp̅ Collisions At √S= 1.8 Tev, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Dec 2001

Search For Gluinos And Squarks Using Like-Sign Dileptons In Pp̅ Collisions At √S= 1.8 Tev, T. Affolder, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present results of the first search for like-sign dilepton (e±e±, e± μ±, μ± μ±) events associated with multijets and large missing energy using 106 pb-1 of data in pp̅ collisions at √s= 1.8 TeV collected during 1992–1995 by the CDF experiment. Finding no events that pass our selection, we examine pair production of gluinos () and squarks () in a constrained framework of the minimal supersymmetric standard model. At tanβ =2 and μ = -800 GeV/c2, we set 95% confidence level limits of M > 221 GeV/c2 for M –̴ Mq ...