Physical Sciences and Mathematics Commons^™

Breeding Bird Census On Four Shelterwood-Cut Stands In Buckingham County, Virginia, Sally Ann Statham

Theses & Honors Papers

The Breeding Bird Census (BBC) technique was used to study breeding bird populations on two paired shelter wood-cut oak stands in Buckingham County, Virginia. The four plots are part of a study to determine oak regeneration following controlled burns in the Virginia piedmont. There is an interest in determining how shelter wood-cut plots affect the breeding birds of Virginia. A total of twenty-seven bird species established and defended territories among the four plots. Ten bird species defended territories on all four plots. All of these species were birds characteristic of forest habitats.

Calibration, Installation Techniques, And Initial Measurements For Vertical Resistivity Probes Used In Hydrogeologic Investigations, Jeffrey Mark Groncki

Masters Theses

Vertical Resistivity Probes (VRPs) are being increasingly used in a variety of applications where detailed vertical resistivity information in both the vadose and saturated zones is needed. All the different possible array types and spacings must be calibrated for the effect of the 2" (outer diameter) insulating PVC cylinder on which the electrodes are mounted. Apparent resistivities must be corrected by calibration factors. Varying the installation parameters greatly influences the measured apparent resistivity because of the disturbed annulus and the composition of the backfill materials. Bentonite slurry is necessary for the installations to keep the electrodes in good contact with …

Reciprocal Transplantation Of The Desert Soil Crust: Can It Be Done?, Christina D. Cole

UNLV Theses, Dissertations, Professional Papers, and Capstones

A 100 meter X 100 meter study site was chosen at White Rock Springs in Red Rock Canyon National Conservation Area, Nevada. To examine Syntrichia caninervis, a desert crustal moss, reciprocal transplantations (20 mm and 40 mm diameter cores) were performed between shaded to shaded, exposed to exposed, and shaded to exposed microsites to determine if it was possible to transplant the study organism with reasonable survivorship. Transplants were inspected following rain events for percent hydration, number of dead stems, and change in percent cover. Data indicated that there was a low mortality rate of S. caninervis stems, and few …

Systemic Environmental Analysis Of The Legal Mechanisms For Controlling Air Pollution In The Las Vegas Valley, Richard Little

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study examines the air pollution control structure for the Las Vegas Valley. A System Dynamics computer model was created that represents the structure of the real world system for controlling air pollution, in order to examine how the current air pollution control system might behave in the future.

Network Security Versus Network Connectivity: A Framework For Addressing The Issues Facing The Air Force Medical Community, Franklin E. Cunningham Jr.

Theses and Dissertations

The Air Force has instituted Barrier Reef to protect its networks. The Air Force medical community operates network connections that are incompatible with Barrier Reef. To overcome this problem, OASD(HA) directed the Tri-Service Management Program Office (TIMPO) to develop an architecture that protects all military health systems and allows them to link with all three services and outside partners. This research studied the underlying networking issues and formed a framework based on data from network experts from the Air Force's medical centers and their base network organizations. The findings were compared TIMPO and a composite framework was developed that more …

Structural And Stratigraphic Relationships Of Ortho- And Paragneisses Southwest Of Marion, North Carolina, Brendan Richardson Bream

Masters Theses

This thesis examines the stratigraphic and structural relationships in the western Inner Piedmont of several orthogneisses and a paragneiss sequence. Detailed mapping was completed for an area slightly larger than one 7.5-minute quadrangle and is located southwest of Marion, North Carolina, at the northeast outcrop termination of the main Henderson Gneiss unit. From bottom to top, the stratigraphy of the study area consists of the Tallulah Falls Formation, Poor Mountain Amphibolite, and Poor Mountain Quartzite. Amphibolites and amphibole gneisses of the Tallulah Falls Formation, Poor Mountain Formation, and Dysartsville gneiss are interpreted as tholeiitic basalts related to rifting along the …

Power, Performance, And Perception (P3): Integrating Usability Metrics And Technology Acceptance Determinants To Validate A New Model For Predicting System Usage, Alan P. Fiorello

Theses and Dissertations

Currently, there are two distinct approaches to assist information technology managers in the successful implementation of office automation software. The first approach resides within the field of usability engineering, while the second approach is derived from the discipline of management information systems (MIS). However, neither approach has successfully produced conclusive evidence that explains what characteristics facilitate system use as well as influence user acceptance of the system. This study reports on the validity of a new model, entitled the Power, Performance, Perception (P3) model, that links the constructs of usability engineering to user acceptance. Additionally, speech recognition software (SRS) was …

Stratigraphic Analysis Of Diamicton Units In North-Central St. Joseph County, Michigan, Andrew C. Flint

Masters Theses

Seven subsurface glacial diamicton units, including a paleosol, have been characterized from two borings in north-central St. Joseph County, Michigan. These units have been characterized in terms of their clay mineralogy, texture, color, and stratigraphic position. t-Tests confirm that each unit displays a significant difference in mean 7A/10A peak height ratio from all other units.

Unit 4, informally called the Gray Marker tilt has been correlated between borings in this study and to the findings of others (Gardner, 1997, Nicks, in preparation). The Newbury till described by the Indiana Geological Survey (unpublished data) may also correlate to Unit 4, raising …

Evaporation Of Jet Fuels, Charles Eric Hack

Theses and Dissertations

Determining the fate and transport of JP-8 jet fuel is a complex and important problem. As part of the startup procedures for jet engines, fuel is passed through aircraft engines before combustion is initiated. Because of the extremely low temperatures at northern tier Air Force bases, the unburned fuel does not evaporate readily and may come into contact with ground crew. To determine the amount and duration of contaminant contact, the evaporation of the emitted fuel must be modeled. The amount and composition of the fuel upon reaching the ground crew may be determined by droplet evaporation models that have …

Trace-Level Determination Of Fluorescently Labeled Phenoxy Acid Herbicides And The Study Of Their Crop Uptake And Soil Accumulation, Noura Saeed Al Nuaimi

Theses

A challenging problem facing the determination of phenoxy acid herbicides in samples is their low UV absorptivity and the interference associated with the matrix in which these analytes exist. This thesis is concerned with improving the detection limits of this group of herbicid as well as reduce or eliminate interference associated with the sample matrix.

Native phenoxy acid herbicides could be analyzed by high performance liquid chromatography (HPLC) with ultraviolet detection. Phenoxy herbicides were analyzed by HPLC employing a gradient conditions that allowed baseline resolution of all analytes used in this study in approximately 20 min. However, the average detection …

Production Of The Subtropical Seagrass, Halodule Wrightii Aschers., In Lower Laguna Madre, Texas, Joseph L. Kowalski

Theses and Dissertations - UTB/UTPA

The autecology of shoal grass, Halodule wrightii Aschers., was studied at 1.2 m depth from June 1995 to February 1997 in Lower Laguna Madre (LLM), Texas. Halodule wrightii in LLM received about 47% surface irradiance, but otherwise displayed lower growth rates and biomass in nutrient-poor rhizosphere and water-column environments compared to H. wrightii populations in other Texas estuaries. High tissue N content and low C:N ratios belied low growth dynamics. Halodule wrightii in LLM is probably nutrient limited. A high nutrient demand by H. wrightii in a nutrient-poor environment may explain, in part, its gradual displacement by Thalassia testudinum and …

A Numerical Simulation Of A Carbon Black Suspension Cell Via A Time-Reversed, Double Layer Compute Algorithm, Gregg T. Anderson

Theses and Dissertations

A numerical simulation of a carbon black suspension cell is explored which models a laser-induced plasma within a liquid ethanol medium of approximately 1 mm thickness. The simulation model assumes a laser pulse with a pulse width of approximately 9 nsecs propagating in the left-to-right direction striking the front surface of the medium and focusing to a spot within the liquid volume. When the energy density within a given irradiated volume is sufficiently high, it ignites the carbon particles and generates a large number of free electrons, i.e., a plasma. The plasma couples with the in-coming laser energy on a …

Information System Incidents: The Development Of A Damage Assessment Model, Mark D. Horony

Theses and Dissertations

Information system (IS) incidents are on the rise. With low manning and undertrained information security specialists it is difficult for organizations to stop IS incidents from occurring. Once an incident has occurred it is the IS manager's responsibility to ensure that a full and accurate damage assessment has been accomplished. However, most IS managers lack the necessary tools to assess the damage from an incident. This exploratory thesis developed an IS incident damage assessment model (DAM) that can be part of the IS manager's tool kit. During the development of the model, it became apparent that the model was supported …

Towards A Game Theory Model Of Information Warfare, David A. Burke

Theses and Dissertations

The repeated game of incomplete information model, a subclass of game theory models, was modified to include aspects of information warfare. The repeated game of incomplete information model was first developed to analyze nuclear weapons disarmament negotiations. The central role of information in this model suggested its applicability to IW, which focuses on the defense and acquisition of information. A randomized experimental design was utilized to determine how people behave in a laboratory IW setting and to test the IW game model's basic predictions. The impact of experience and learning on IW performance was also assessed during the experiment. IW …

Application Of The Interaction Picture To Reactive Scattering In One Dimension, Michael J. Maclachlan

Theses and Dissertations

The interaction picture is used together with the channel-packet method in a new time-dependent approach to compute reactive scattering matrix elements. The channelpacket method enables the use of the interaction picture for computing reactive S-matrix elements by splitting the computational effort into two parts. First, asymptotic reactant and product wavepackets are individually propagated into the interaction region of the potential to form Moller states. The interaction picture, in contrast to the usual Schrödinger picture of quantum mechanics, is so constructed that a wavefunction that experiences no change in potential (that is, a free-particle wavefunction) remains always fixed, with no translation …

Mineral Paragenesis And Ore Fluids At The Turquoise Ridge Gold Deposit, Nevada, Michiko Shigehiro

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this study, mineral assemblages and related fluid inclusions at the Turquoise Ridge Carlin-type gold deposit were examined to answer the following questions: (1) What is the ore-stage mineral paragenesis? (2) At what pressures and temperatures did the deposits form? (3) What are the sources of ore fluids?

Pyrite with gold, jasperoid quartz, stibnite, orpiment, realgar, and calcite were successively deposited at Turquoise Ridge. Microthermometric data and isotopic ratios of inclusion fluids in ore-related minerals indicate entrapment of multiple generations of fluids in pre-ore, ore-, and late-ore stage minerals. Primary fluid inclusions in an ore-stage jasperoid quartz crystal have salinities …

Alteration Associated With Gold Deposition At The Getchell, Carlin-Type Gold Deposit, North-Central Nevada, Tracy Lynn Cail

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alteration at the Getchell deposit was examined to determine the effects of ore-bearing fluids on host lithologies and the relationship between K-bearing alteration minerals and Au deposition. The geochemistry of unaltered to highly altered and mineralized rocks from the Getchell deposit was quantified for 54 samples collected along 14 transects in calcareous siltstone, carbonaceous limestone, and a rhyodacitic dike. Each transect was collected along a single homogeneous bed that could be followed from visibly unaltered waste rock into high-grade ore.

Calculated elemental gains and losses record an increase in the concentrations of Au, Hg, Sb, Se, Si, Te, Tl, and …

Implementation Of Speech Recognition Software For Text Processing: An Exploratory Analysis, Sean P. Abell

Theses and Dissertations

The rationale behind implementing new information technologies is often to gain productivity improvements associated with the substitution of machinery for labor. However, the literature shows little direct evidence of a positive relationship between information technology investment and subsequent productivity benefits. This thesis reports on the examination into the productivity implications of implementing speech recognition software in a text processing environment. More specifically, research was conducted to compare text processing speeds and error rates using speech recognition software versus the keyboard and mouse. Of interest was the time required to input and proofread text processing tasks as well as the number …

Alkyl Nitrates During The Prophet ’98 Summer Intensive, Kristi A. Ostling

Masters Theses

As part of the PROPHET intensive held at the University of Michigan Biological Station in northern Michigan, a gas chromatography system for making fast-turnaround measurements of C1 to C5 alkyl nitrates was developed and deployed from July 19 to August 21, 1998. Every 30 minutes, samples were automatically acquired on a small Tenax trap made from silicosteel column and injected on a GC column by thermal desorption prior to ECD detection. Tests performed to measure breakthrough and on-trap destruction indicated no breakthrough for C3, C4, and C5 nitrates and excellent stability for these compounds on the trap. Chromatographic resolution of …

The Effect Of Divalent Cations On The Prophenoloxidase Enzyme Cascade Activity In The Freshwater Crayfish Cambarus Latimanus, Hans Skailand Eikaas

Theses and Dissertations

The effect of divalent cations such as cadmium, calcium, copper, lead and magnesium upon the prophenoloxidase system (proPO) was studied in hemocytes of the crayfish Cambarus latimanus. It was demonstrated that cadmium, calcium, copper and lead increased proPO activity significantly, whereas magnesium had no statistically significant effect on the system. Also, the molecular weight of the proPO enzyme was estimated using SDS-PAGE and found to be approximately 76 kDa.

On Measuring The Cost Of Children:The Case Of Rural Maharashtra., Manisha Chakrabarty Dr.

Doctoral Theses

In this dissertation we have attempted to measure the cost of children, which plays a crucial role in matters relating to welfare and public policy like child benefits and compensation policies of the government. The cost is measured based on the single equation as well as the systems approach using the 38th round National Sample Survey (NSS) data on household consumer expenditure for rural Maharashtra (relating to the period of January to December, 1983).The first chapter provides a brief account of the basic literature on empirical demand analysis which is relevant for welfare comparison between households. To be specific in …

To Host A Legacy System To The Web, Miguel Angel Bustamante

Student Work

The dramatic improvements in global interconectivity due to intranets, extranets and the Internet has led to many enterprises to consider migrating legacy systems to a web based systems. While data remapping is relatively straightforward in most cases, greater challenges lie in adapting legacy application software. This research effort describes an experiment in which a legacy system is migrated to a web-client/server environment. First, this thesis reports on the difficulties and issues arising when porting a legacy system International Invoice (IIMM) to a web-client/server environment. Next, this research analyzes the underlying issues, and offer cautionary guidance to future migrators and finally …

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

UNLV Theses, Dissertations, Professional Papers, and Capstones

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

The Microchannel Flow Of A Micropolar Fluid, Guohua Liu

Doctoral Dissertations

Micro-channel flows have been computed to investigate the influence of Navier-Stokes formulation for the slip-flow boundary condition, and a micro-polar fluid model, respectively.

The results of the slip boundary condition show that the current methodology is valid for slip-flow regime (i.e., for values of Knudsen number less than approximately 0.1). Drag reduction phenomena apparent in some micro-channels can be explained by slip-flow theory. These results are in agreement with some computations and experiments.

An ad hoc micro-polar fluid model is developed to investigate the influence of micro effects, such as micro-gyration, in micro-scale flows. The foundation of the ad hoc …

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

Chemistry & Biochemistry Theses & Dissertations

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

Efficient Simulation Via Validation And Application Of An External Analytical Model, Thomas H. Irish

Theses and Dissertations

This research makes significant contributions towards improving the efficiency of simulation studies using an external analytical model. The foundation for this research is the analytical control variate (ACV) method. The ACV method can produce significant variance reduction, but the resulting point estimate may exhibit bias. A Monte Carlo sampling method for resolving the bias problem is developed and demonstrated through a queueing network example. The method requires knowledge of the parameters and approximate distributions of the random variables used to produce the ACV. Often, some of these parameters or distributions are not known. Both parametric and non-parametric alternatives to the …

Formal Representation And Application Of Software Design Information, Thomas M. Schorsch

Theses and Dissertations

Formal methods for developing software use mathematical frameworks to specify, develop and verify software systems, especially safety critical systems where error free software is a necessity. A transformation system is a formal method that refines a requirement specification into an implementation by successively adding design decisions in the form of precisely verified design information. Current algebraic representations of design information (specifications, morphisms, and interpretations) and methods for applying algebraic specification design information (diagram refinement) cannot correctly represent and apply design information involving higher level design information. This investigation develops innovative methods for constructing and refining structured algebraic requirement specifications, as …

Multiple Comparison Pruning Of Neural Networks., Donald E. Duckro

Theses and Dissertations

Reducing a neural network's complexity improves the ability of the network to be applied to future examples. Like an overfitted regression function, neural networks may miss their target because of the excessive degrees of freedom stored up in unnecessary parameters. Over the past decade, the subject of pruning networks has produced non-statistical algorithms like Skeletonization, Optimal Brain Damage, and Optimal Brain Surgery as methods to remove connections with the least salience. There are conflicting views as to whether more than one parameter can be removed at a time. The methods proposed in this research use statistical multiple comparison procedures to …

Protein And Endotoxin Interactions And Endotoxin Removal From Protein Solutions, Liping Li

Dissertations

The investigation objectives of this study include: endotoxin disaggregation by proteins; protein concentration effect on protein-endotoxin binding and endotoxin removal; size exclusion high performance liquid chromatography (SE-HPLC) studies on endotoxin dissociation by bovin serum albumin (BSA); use of Ca⁺² to re-aggregate endotoxin in hemoglobin solutions and the subsequent removal of endotoxin by ultrafiltration; quantitative determination of Ca⁺² effects on endotoxin removal and protein yield in a two-stage ultrafiltration.

It is known that some proteins can disaggregate endotoxins and form complexes with lipopolysaccharides (LPS). It is also known that Ca can act as "bridges" to aggregate LPS in aqueous …

Comparative Molecular Field Analysis (Comfa) Of Phenyl Ring Substituted Methylphenidates, Milind Misra

Theses

Comparative Molecular Field Analysis (CoMFA) was performed on 30 methylphenidate analogues having phenyl ring substituents at the 2-, 3-, and 4-positions in an attempt to explain the structure-activity relationships of the analogues. Several CoMFA studies were carried out using different conformations of methylphenidate as the template structures for the corresponding alignment rules. The identification of the bioactive conformation was variously based on the interfeature distances in WIN 35,428, on cluster analysis, and on a comparison of active methylphenidate analogues. The sensitivity of the models to various CoMFA parameters was compared. These parameters included altering the size and spacing of the …