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2001

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Articles 2701 - 2730 of 2764

Full-Text Articles in Physical Sciences and Mathematics

Mathematical Models Of Quiescent Solar Prominences, Iain Mckaig Jan 2001

Mathematical Models Of Quiescent Solar Prominences, Iain Mckaig

Mathematics & Statistics Theses & Dissertations

Magnetic fields in the solar atmosphere suspend and insulate dense regions of cool plasma known as prominences. The convection zone may be the mechanism that both generates and expels this magnetic flux through the photosphere in order to make these formations possible. The connection is examined here by modeling the convection zone as both one-dimensional, then more realistically, two-dimensional.

First a Dirichlet problem on a semi-infinite strip is solved using conformal mapping and the method of images. The base of the strip represents the photosphere where a current distribution can be given as a boundary condition, and the strip extends …


The Coupling Of Biotechnology With Electrochemistry: Electrodenitrification Of Water Using The Enzyme Nitrate Reductase, Cyril Geyer Jan 2001

The Coupling Of Biotechnology With Electrochemistry: Electrodenitrification Of Water Using The Enzyme Nitrate Reductase, Cyril Geyer

Dissertations and Theses @ UNI

Nitrate is a worldwide contaminant that causes environmental (eutrophication) and human health (methemoglobinemia, cancers) concerns. Very few techniques are available to eliminate it from natural environment and they suffer from major drawbacks, such as production of unwanted byproducts (toxins or brine). The electrochemical reduction of nitrate on any electrode is relatively slow and catalysts or electron mediators are needed. The goal of this project was to develop a new process that could overcome these disadvantages. The project demonstrates the feasibility of using an enzyme, nitrate reductase, and a mediator, methyl viologen to transfer the electrons from the electrode to nitrate, …


An Analysis Of A Radio Frequency Sensor As A Means To Remotely Sense Selected Surface Topographies In An Agriculture Environment, Barry Michael Alexia Jan 2001

An Analysis Of A Radio Frequency Sensor As A Means To Remotely Sense Selected Surface Topographies In An Agriculture Environment, Barry Michael Alexia

Dissertations and Theses @ UNI

Remote sensing is the science and art of obtaining information about an object, area or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation. The remotely sensed data can be of many forms, including variations in force distribution, acoustic wave distribution, or electromagnetic energy distribution.Information thus acquired can be used for observing,monitoring, and studying planetary surfaces and environments.

Because there are many ways to acquire data about targets of interest, there are many types of remote sensors that can be used, including visible, infrared, and active …


Corba: A Quantitative And Qualitative Comparison Of Industrial Strength, Commercial Corba Orbs For The Java Platform, Michelle Leigh Mckeller Jan 2001

Corba: A Quantitative And Qualitative Comparison Of Industrial Strength, Commercial Corba Orbs For The Java Platform, Michelle Leigh Mckeller

UNF Graduate Theses and Dissertations

In distributed systems design, middleware is a key component. Middleware establishes the communication between a client and server in a multi-tiered architecture. One approach to middleware is implementing the OMG's CORBA standard, through the use of ORBs. Three of the more popular commercially available ORBs are Sun's Java 2 ORB, Borland's VisiBroker for Java, and IONA's Orbix 2000 for Java. The purpose of this graduate project was to compare the three ORBs both quantitatively and qualitatively. The project compares the ORBs quantitatively by measuring the performance of each ORB, in terms of response time. The comparison was done qualitatively by …


Teaching Effectiveness In An Introductory High School Honors Physics Course As Measured By The Force Concept Inventory, April Crawford Moore Jan 2001

Teaching Effectiveness In An Introductory High School Honors Physics Course As Measured By The Force Concept Inventory, April Crawford Moore

Dissertations and Theses @ UNI

Of importance to many teachers is that students emerge from a course of study with an acceptable level of comprehension of the subject matter presented and that students' course grades reflect that understanding. The primary question of this research was, "How effective in promoting comprehension of Newtonian concepts is this teacher's use of selected interactive strategies?" Secondary questions were: 1. What modifications to instruction, if any, have to be made for implementation of interactive-engagement strategies? 2. Following instruction in mechanics, which misconceptions probed by the Force Concept Inventory (FCI) are retained by students, and which misconceptions are corrected? 3. How …


Field Methodology For The Determination Of The Prevalence Of Giardia Cysts And Cryptosporidium Oocysts Drinking Water And Its Association To The Development Of Diarrheal Disease In The Transylvania Region Of Romania, Rick J. Bauer Jan 2001

Field Methodology For The Determination Of The Prevalence Of Giardia Cysts And Cryptosporidium Oocysts Drinking Water And Its Association To The Development Of Diarrheal Disease In The Transylvania Region Of Romania, Rick J. Bauer

Dissertations and Theses @ UNI

The purpose of this study was to analyze the drinking water of 69 individuals living in the Transylvania region of Romania for the presence of Giardia cysts and Cryptosporidium oocysts. The ultimate objective was to determine if a correlation exists between the presence and concentrations of these two protozoa and the reported frequency and average severity of diarrheal disease in the study group members.

To accomplish this goal, a collection, emulsion, concentration, labeling, and identification method had to be developed that could operate effectively in an international field setting. The protocol selected included the collection of samples using a compressed …


La Révolution Scientifique, Les Révolutions, Et L'Histoire Des Sciences. Comment Ernest Coumet Nous A Libérés De L'Héritage D'Alexandre Koyré, Marco Panza Jan 2001

La Révolution Scientifique, Les Révolutions, Et L'Histoire Des Sciences. Comment Ernest Coumet Nous A Libérés De L'Héritage D'Alexandre Koyré, Marco Panza

MPP Published Research

Dans son intervention au colloque Koyré (Paris, 1986), Ernest Coumet a suggéré que le terme «révolution scientifique» ne désigne pas chez Koyré un événement historique, mais un idéaltype, au sens de Max Weber. L'auteur discute d'abord cette thèse de Coumet et expose les arguments que ce dermier apporte pour la soutenir. Dans la deuxième partie de l'article, il critique l'usage de la notion de révolution en histoire des sciences, en s'opposant en particulier à la possibilité de distinguer dans les productions des savants une «pensée scientifique» qui serait influencée par la «pensée philosophique» et dont les bouleversements marqueraient l'avènement d'une …


Gravitational Descendants And The Moduli Space Of Higher Spin Curves, Tyler J. Jarvis, Takashi Kimura, Arkady Vaintrob Jan 2001

Gravitational Descendants And The Moduli Space Of Higher Spin Curves, Tyler J. Jarvis, Takashi Kimura, Arkady Vaintrob

Faculty Publications

The purpose of this note is introduce a new axiom (called the Descent Axiom) in the theory of r-spin cohomological field theories. This axiom explains the origin of gravitational descendants in this theory. Furthermore, the Descent Axiom immediately implies the Vanishing Axiom, explicating the latter (which has no a priori analog in the theory of Gromov-Witten invariants), in terms of the multiplicativity of the virtual class. We prove that the Descent Axiom holds in the convex case, and consequently in genus zero.


Adaptive Web Sites By Web Usage Mining, Mario Rodney Creado Jan 2001

Adaptive Web Sites By Web Usage Mining, Mario Rodney Creado

Masters Theses

The World Wide Web has become a very popular marketing medium during the recent years. Many businesses use it extensively to publicize their products. Initially it began with static web sites. However as web sites got bigger and better, their maintenance became problematic. Just as business strategies change, so also will the orgainization of their web sites change. Hence the need of the hour is an adaptive web site (i.e. a web site that can organize itself based upon its usage). For this purpose, web usage mining techniques are used. The characteristics of the user's activity on the web site …


Constraining The Crystallization And Post-Crystallization History Of The Wallamatogus Pluton, Maine, Using Compositional Data From Garnet, Biotite And Muscovite, Joy Kathleen Drake Jan 2001

Constraining The Crystallization And Post-Crystallization History Of The Wallamatogus Pluton, Maine, Using Compositional Data From Garnet, Biotite And Muscovite, Joy Kathleen Drake

Masters Theses

"The Wallamatogus Pluton, Maine, exhibits systematic variation in grain size, mineralogy, and phenocryst abundance (alkali-feldspar) from the margin to the center of the pluton. Three facies are recognized: 1) outermost, seriate, coarse-grained (Owe), 2) porphyritic medium- to fine-grained (Dwp ), 3) innermost, fine-grained equigranular (Dwf). These facies are concentrically arranged and their contacts are gradational. Muscovite and biotite occur in all facies; the outer two facies contain garnet, and tourmaline. Muscovite and biotite grains within micaceous enclaves compositionally overlap primary muscovite, suggesting that they are early-crystallized accumulations. Muscovite in multiphase clusters and secondary muscovite compositionally overlap, suggesting formation during post-crystallization …


A Web-Enabled Temporal Database Human Resources Application, Joseph A. Brooke Iii Jan 2001

A Web-Enabled Temporal Database Human Resources Application, Joseph A. Brooke Iii

UNF Graduate Theses and Dissertations

Despite the inclusion of a variety of time-related or 'temporal' datatypes in the SQL-92 standard, vendors of commercially-available Relational Database Management Systems (RDBMS) have universally elected to not fully comply with the standard. Perhaps even more frustrating is the fact that each vendor has chosen to include a different subset of temporal datatypes than their competitors, with most vendors adding a proprietary twist to their datatypes not even contained within the standard.

This lack of conformity has left users of these database products faced with a difficult choice: either avoid temporal functionality within their database applications or develop and manage …


Single-Pulse Characteristics Of The Millisecond Radio Pulsar Psr B1937 + 21 At 430 Mhz, F. A. Jenet, S. B. Anderson, T. A. Prince Jan 2001

Single-Pulse Characteristics Of The Millisecond Radio Pulsar Psr B1937 + 21 At 430 Mhz, F. A. Jenet, S. B. Anderson, T. A. Prince

Physics & Astronomy Faculty Publications

The single-pulse characteristics of the millisecond pulsar PSR B1937 + 21 are studied using the recently installed Caltech baseband recorder at the Arecibo Radio Observatory in Puerto Rico. This is the first such analysis of this object that includes both average intensity pulses as well as \"giant pulses.\" Pulse ensemble-averaging techniques are developed in order to study the characteristics of PSR B1937 + 21's single pulses since the high time resolution signal-to-noise ratio is less than unity. This analysis reveals that the non-giant pulse radio emission is extremely stable. All observed fluctuations are consistent with diffractive interstellar scattering. Such intrinsic …


Spatial Distribution Of Phosphorus In Fluvial Sediments From The James River Basin, Sw Missouri, Briain Fredrick Jan 2001

Spatial Distribution Of Phosphorus In Fluvial Sediments From The James River Basin, Sw Missouri, Briain Fredrick

Graduate Theses/Dissertations

Degraded ·water quality in the James River Arm of Table Rock Lake, southwest Missouri has raised concerns about sources and transport of nutrients, especially phosphorus, in the James River Basin. Sections of the James River Basin have been identified as having excessive nutrient problems on the Missouri Department of Natural Resources 303d list and ranked fifth in the state for water quality improvements. Understanding the sources and transport patterns of phosphorus in the James River is necessary to evaluate contamination problems and the effectiveness of management efforts to reduce phosphorus inputs to the lake. This study uses bed sediments to …


Spatial Patterns And Floodplain Contributions Of Mining-Related Contaminants In Chat Creek Watershed, Southwest Missouri, Jimmy Trimble Jan 2001

Spatial Patterns And Floodplain Contributions Of Mining-Related Contaminants In Chat Creek Watershed, Southwest Missouri, Jimmy Trimble

Graduate Theses/Dissertations

Past mining activities have left a legacy of water quality problems in the Tri-State Mining District. Contemporary environmental risks stem from the release of lead and zinc from mine tailings previously dispersed far downstream in alluvial deposits as well as abandoned tailings piles. This study examines mining-related heavy metal contamination in the Chat Creek Watershed. Chat Creek drains the area near Aurora, Missouri on the eastern edge of the Tri-State District where mining occurred from 1886 to about 1930. This study identifies the spatial distribution of metal contamination in fluvial sediments and quantifies the role of bank erosion as a …


Verification Of A Distortion In The Microstructure Of Gan Detected By Exafs Using Ab Initio Density Functional Theory Calculations, Nicholas Dimakis, Grant Bunker, M. Katsikini, E. C. Paloura Jan 2001

Verification Of A Distortion In The Microstructure Of Gan Detected By Exafs Using Ab Initio Density Functional Theory Calculations, Nicholas Dimakis, Grant Bunker, M. Katsikini, E. C. Paloura

Physics & Astronomy Faculty Publications

X-ray absorption fine structure (XAFS) measurements on a series of epitaxially grown GaN samples have shown a distortion in the microstructure of GaN. More specifically the central N atom is 4-fold coordinated but the four Ga atoms are not equidistant. It has been shown that 2.9 to 3.5 of them (depending on the growth conditions) are found in the expected from XRD distance of 1.94 A and the remaining are at a distance longer by approximately 15%. Second derivative calculation of the conformation energy using the Density Functional Theory (DFT) is used to investigate if the symmetric GaN cluster as …


Polymer Depletion Interaction Between Two Parallel Repulsive Walls, F. Schlesener, Andreas Hanke, R. Kimpel, S. Dietrich Jan 2001

Polymer Depletion Interaction Between Two Parallel Repulsive Walls, F. Schlesener, Andreas Hanke, R. Kimpel, S. Dietrich

Physics & Astronomy Faculty Publications

The depletion interaction between two parallel repulsive walls confining a dilute solution of long and flexible polymer chains is studied by field-theoretic methods. Special attention is paid to self-avoidance between chain monomers relevant for polymers in a good solvent. Our direct approach avoids the mapping of the actual polymer chains on effective hard or soft spheres. We compare our results with recent Monte Carlo simulations [A. Milchev and K. Binder, Eur. Phys. J. B 3, 477 (1998)] and with experimental results for the depletion interaction between a spherical colloidal particle and a planar wall in a dilute solution of nonionic …


Modified Critical Correlations Close To Modulated And Rough Surfaces, Andreas Hanke, Mehran Kardar Jan 2001

Modified Critical Correlations Close To Modulated And Rough Surfaces, Andreas Hanke, Mehran Kardar

Physics & Astronomy Faculty Publications

Correlation functions are sensitive to the presence of a boundary. Surface modulations give rise to modified near surface correlations, which can be measured by scattering probes. To determine these correlations, we develop a perturbative calculation in deformations in height from a flat surface. The results, combined with a renormalization group around four dimensions, are also used to predict critical behavior near a self-affine rough surface. We find that a large enough roughness exponent can modify surface critical behavior.


Chemical Transferability Of Single- And Multiple-Scattering Exafs Debye-Waller Factors, Nicholas Dimakis, Grant Bunker Jan 2001

Chemical Transferability Of Single- And Multiple-Scattering Exafs Debye-Waller Factors, Nicholas Dimakis, Grant Bunker

Physics & Astronomy Faculty Publications

Single- and multiple-scattering EXAFS Debye-Waller factors are amplitude reduction parameters that appear in the EXAFS x(k) equation accounting for the structural and thermal disorder of a given sample. These parameters must be known accurately in order to obtain quantitative agreement between theory and experiment. Since experimental data can only support a limited number of fitted parameters these factors must be known from another source. Although various approaches have been considered in the past with a variety of results, the self-consistent ab initio Density functional theory stands for the most accurate and reliable method regardless of molecular symmetry or other specific …


Apex Version 2.0: Latest Version Of The Cross-Platform Analysis Program For Exafs, Nicholas Dimakis, Grant Bunker Jan 2001

Apex Version 2.0: Latest Version Of The Cross-Platform Analysis Program For Exafs, Nicholas Dimakis, Grant Bunker

Physics & Astronomy Faculty Publications

This report describes recent progress on APEX, a free, open source, cross platform set of EXAFS data analysis software. In a previous report we described APEX 1.0 (Dimakis, N. and Bunker, G., 1999), a free and open source code suite of basic X-Ray Absorption Fine Structure (XAFS) data analysis programs for classical data reduction and single scattering analysis. The first version of APEX was the only cross platform (linux/irix/windows/MacOS) EXAFS analysis program to our knowledge, but it lacked important features like multiple scattering fitting, generic format conversion from ASCII to University of Washington (UW) binary-type files, and user friendly interactive …


Probing The Strong Boundary Shape Dependence Of The Casimir Force, Thorsten Emig, Andreas Hanke, Ramin Golestanian, Mehran Kardar Jan 2001

Probing The Strong Boundary Shape Dependence Of The Casimir Force, Thorsten Emig, Andreas Hanke, Ramin Golestanian, Mehran Kardar

Physics & Astronomy Faculty Publications

We study the geometry dependence of the Casimir energy for deformed metal plates by a path integral quantization of the electromagnetic field. For the first time, we give a complete analytical result for the deformation induced change in Casimir energy δE in an experimentally testable, nontrivial geometry, consisting of a flat and a corrugated plate. Our results show an interesting crossover for δE as a function of the ratio of the mean plate distance H, to the corrugation length λ: For λ≪H we find a slower decay ∼H−4, compared to the H−5 behavior predicted by the commonly used pairwise summation …


An Assessment Of The Role And Impact Of Non-Governmental Organizations (Ngos) In The Management And Sustainability Of Local Environmental Resources: A Case Study Of Nanun, Ghana, Iddrisu Adam Jan 2001

An Assessment Of The Role And Impact Of Non-Governmental Organizations (Ngos) In The Management And Sustainability Of Local Environmental Resources: A Case Study Of Nanun, Ghana, Iddrisu Adam

Theses and Dissertations (Comprehensive)

NGOs have been heralded as the vehicle of choice for aid delivery by international organizations lice the World Bank and the United Nations and also by western governments, especially in the last two decades. This is a tacit acceptance of their role as development agents in the South. However, no substantive research has been done to find out if these NGOs are indeed contributing to the better management of local environmental resources. This research sets out to examine the role and impact of non-governmental organizations (NGOs) in the management and sustainability of local environmental resources in rural Ghana. What makes …


Weathering Crust Processes On Melting Glacier Ice (Alberta, Canada), Corinne Joanne Schuster Jan 2001

Weathering Crust Processes On Melting Glacier Ice (Alberta, Canada), Corinne Joanne Schuster

Theses and Dissertations (Comprehensive)

This thesis examines the relationship between the energy balance and hydrology of a glacier at the ice surface interface during the melt season. Experimental sub-catchments were established on the ablation area of the Peyto Glacier, Alberta, Canada, during the summers of 1994, 1995 and 1997. These sub-catchments were equipped with meteorological and hydrological instrumentation to examine relationships in the surface layer. Specifically, the development of a phenomenon known as the weathering crust is followed by examining the ratio between potential surface lowering (calculated from energy available for melt) and actual surface lowering (as measured in the field). This enables an …


"References" For Carnivore Conservation, John L. Gittleman, Stephan M. Funk, David Macdonald, Robert K. Wayne, Eric M. Gese Jan 2001

"References" For Carnivore Conservation, John L. Gittleman, Stephan M. Funk, David Macdonald, Robert K. Wayne, Eric M. Gese

United States Department of Agriculture Wildlife Services: Staff Publications

119-page bibliography of works cited in in CARNIVORE CONSERVATION, edited by John L. Gittleman, Stephan M. Funk, David Macdonald, and Robert K. Wayne, Cambridge University Press, 2001.

Includes approximately 2,000 items.


Experimental Infection Of Nontarget Species Of Rodents And Birds With Brucella Abortus Strain Rb51 Vaccine, Matt C. Januszewski, Steven C. Olsen, Robert G. Mclean, Larry Clark, Jack C. Rhyan Jan 2001

Experimental Infection Of Nontarget Species Of Rodents And Birds With Brucella Abortus Strain Rb51 Vaccine, Matt C. Januszewski, Steven C. Olsen, Robert G. Mclean, Larry Clark, Jack C. Rhyan

United States Department of Agriculture Wildlife Services: Staff Publications

The Brucella abortus vaccine strain RB51 (SRB51) is being considered for use in the management of brucellosis in wild bison (Bison bison) and elk (Cervus elaphus) populations in the Greater Yellowstone Area (USA). Evaluation of the vaccine’s safety in non-target species was considered necessary prior to field use. Between June 1998 and December 1999, ground squirrels (Spermophilus richardsonii, n=21), deer mice (Peromyscus maniculatus, n=14), prairie voles (Microtus ochrogaster, n=21), and ravens (Corvus corax, n=13) were orally inoculated with SRB51 or physiologic saline. Oral and …


Serological Responses Of Coyotes To Two Commercial Rabies Vaccines, Frederick F. Knowlton, Marianna Roetto, Deborah Briggs Jan 2001

Serological Responses Of Coyotes To Two Commercial Rabies Vaccines, Frederick F. Knowlton, Marianna Roetto, Deborah Briggs

United States Department of Agriculture Wildlife Services: Staff Publications

Between August 1993 and September 1994 we documented serological responses of coyotes (Canis latrans) vaccinated with two commercial rabies vaccines licensed for use in domestic dogs. Serologic responses were documented by testing for rabies virus neutralizing antibodies with the rapid fluorescent focus inhibition test (RFFIT) at 30, 90, 180, 270, and 365 days post-vaccination. All coyotes vaccinated with Imrab 3® (Rhone-Merieux, Inc.), and 75% of those vaccinated with Dura-Rab 3® (Immunovet, Inc.) seroconverted, as evidenced by the presence of antirabies antibody titers ≥1:5 in one or more of the five post-vaccination samples. The percent of coyotes …


Focus Group Evaluation For Web-Based Courses, James P. Turley, Meena Hussein, Doris L. Ross Jan 2001

Focus Group Evaluation For Web-Based Courses, James P. Turley, Meena Hussein, Doris L. Ross

Faculty, Staff and Student Publications

No abstract provided.


Dental Postgraduates Prefer Hypertutorial Statistics Lessons In Randomized Web Course Comparisons, Craig W. Johnson Jan 2001

Dental Postgraduates Prefer Hypertutorial Statistics Lessons In Randomized Web Course Comparisons, Craig W. Johnson

Faculty, Staff and Student Publications

No abstract provided.


So You Want To Work With Wolves?, John A. Shivik Jan 2001

So You Want To Work With Wolves?, John A. Shivik

United States Department of Agriculture Wildlife Services: Staff Publications

Growing up with three older sisters was a bit like being raised by wolves. One of their favorite games was called “stop hitting yourself.” To play, I was immobilized, and then with my arms overpowered, I was forced to repeatedly pummel my own noggin while they uttered the name of the game. Watching yourself hit yourself, feeling the pain and humiliation, yet being unable to stop is somewhat like being a federal biologist working with wolves. I’ve learned humility from my experiences but also formed the opinion that if you want to work with wolves, first consider medication; if that …


Non-Target Hazard Assessment Of Using Drc-1339 Avicide To Manage Blackbirds In Sunflower, John D. Eisemann, George M. Linz, John J. Johnston Jan 2001

Non-Target Hazard Assessment Of Using Drc-1339 Avicide To Manage Blackbirds In Sunflower, John D. Eisemann, George M. Linz, John J. Johnston

United States Department of Agriculture Wildlife Services: Staff Publications

Terrestrial hazard assessments were conducted for the spring blackbird baiting program to protect sunflower crops. Risk Assessment methodology proposed by the Ecological Committee on FIFRA Risk Assessment Methods (ECOFRAM) and the method currently used by the U.S. Environmental Protection Agency (LD50s/ft2) were compared for their predictive strengths and for the ease of adapting the assessment to site specific conditions. While the ECOFRAM and LD50s/ft2 methods identified the same groups of organisms as being at risk, the flexibility of the ECOFRAM methodology allowed more latitude in adapting the assessment to unique behaviors of individual …


Estimation Of Red-Winged Blackbird Mortality From Toxic Bait Application, James F. Glahn, Michael L. Avery Jan 2001

Estimation Of Red-Winged Blackbird Mortality From Toxic Bait Application, James F. Glahn, Michael L. Avery

United States Department of Agriculture Wildlife Services: Staff Publications

Application of slow-acting toxic bait is one method of reducing local populations of depredating blackbirds. Estimating numbers of birds killed in such baiting operations is difficult because affected birds die off-site and are seldom recovered. We conducted bioassays and flight pen studies of red-winged blackbirds (Agelaius phoeniceus) with a slow-acting, toxic brown rice bait to determine whether bird mortality could be predicted accurately using the Poisson and binomial discrete probability distributions. Bioassays confirmed that brown rice treated with 2% (w/w) 2-chloro-p-acetotoluidide was effective as a 1-particle lethal bait for redwings. Within a 0.2-ha flight pen, we offered this …