Physical Sciences and Mathematics Commons^™

Quaternary Geology And Neotectonics Of Southern Star Valley And The Southwest Flank Of The Salt River Range, Western Wyoming, Gregory A. Warren

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Southern Star Valley is a structural and physiographic basin bounded on the east by the southern Star Valley fault, an active normal fault associated with Basin and Range extension. The southern Star Valley fault separates southern Star Valley from the Salt River Range and forms a dramatic north-south trending topographic escarpment. Statistical analysis of relative-age dating (RD) parameters taken from glacial deposits in the Salt River Range defined distinctive age groups for the deposits, and comparison of RD data allowed correlations with late Pleistocene and Holocene glacial deposits elsewhere in the Rocky Mountains. However, the sedimentary lithologies in the glacial …

Spatial And Temporal Variations Of The Pilot Valley Playa Interpreted From Remotely Sensed Images, Llyn Doremus

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the Basin and Range Province, the geologic regime of the Pilot Valley, linear trending block faults have isolated many valleys both topographically and hydrologically. Discharge from these arid, closed basins occurs only as evaporation. Minerals dissolved in discharging fluid are precipitated at the valley floor as the liquid evaporates. The resulting salt flats and high density brines are known as playas.

The Pilot Valley Playa surface was sampled concurrently with the recording of a Thematic Mapper remotely sensed image to define the surface conditions that correspond to image data. An association was found between the band 7 (infrared wavelength …

Desert Bighorn Sheep And Riverboat Interactions In Cataract Canyon, Utah, Mark C. Stanger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I studied desert bighorn sheep (Ovis canadensis nelsoni) behavior and habitat use in response to boating activities during 1985. The percent of total observed time in attention behavior before the boating season, during the boating season, and while riverboats were< 0.8 km from bighorn sheep groups was 1, 1.4, and 12.2, respectively. Estimated energy expenditure did not significantly differ for high riverboat pressures (2 > 0.2) or seasonal comparisons (2 > 0.1). Habitat use significantly differed for proximity to the river, which was probably related to the summer use of the river for drinking. Moderate, minor, and no responses to passing riverboats were observed 3, 39, and 58%, respectively. Responses to riverboats did not significantly differ according to time of day (2 > 0.15) or …

The Influence Of Redd Distribution And Microhabitat Availability On The Distribution And Abundance Of Young-Of-The-Year Trout In The Green River, Utah, Michael J. Buntjer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Redd distribution, redd density, and physical habitat were used to explain the distribution and abundance of young-of-the-year (YOY) brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) in the Green River, Utah. The importance of variables at both a microhabitat and macrohabitat scale were assessed using stepwise regression analysis. Availability of cover (rock and vegetation) and proximity to spawning sites were the most important variables used to explain the distribution and abundance of YOY brown trout and rainbow trout. In addition, YOY brown trout and rainbow trout occupied specific microhabitats and showed patterns of use for …

Dynamic Multi-Species Animal Habitat Modeling With Forest Succession Models, Stephen A. Compton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research determines and demonstrates the ability to simulate dynamic multi-species animal habitat suitability with forest succession models. A literature review of dynamic animal habitat models is presented. The structure of an existing forest simulation model (MASS10) was modified from a basal area-based model to a volume-based model (DYNAM10). The forest model was calibrated using data from permanent-plot growth and vegetation samples collected by USDA Forest Service Forest Survey procedures. The theoretical growth parameters used to simulate stand development were validated. Predictions of DBH and height growth, as well as stand-level behavior, were verified. A subroutine, VEGDYN, was added to …

Soil Heterogeneity And Its Exploitation By Plants, Robert B. Jackson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this dissertation I first examine the ability of individual plants in the field to garner localized soil nutrients. I then measure actual soil variability around perennial plants and use various statistics to quantify the scale and degree of that variability.

Soil patches on opposite sides of Pseudoroegneria spicata tussocks were treated with distilled water or a nutrient solution containing N, P, or K in three field experiments. When P was augmented in the enriched soil patches, rates of P uptake increased significantly for roots from enriched patches compared with roots in control patches. Rates of ammonium and potassium uptake …

An Embedded Ring Approach To The Vibrational Dynamics Of Disordered Two-Dimensional Materials, Timothy Edwin Doyle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A theoretical approach was developed to model the vibrational dynamics of amorphous, two-dimensional materials. The materials were modeled as continuous random networks (CRN's) comprising an assemblage of planar rings of diverse size. In-plane vibrational modes for symmetric 4-, 5-, 6-, 7-, and 8-membered rings were examined. Vibrational states of isolated rings were modified by coupling the rings to a continuous network to represent rings embedded in a CRN. An effective force constant was used to couple the ring vibrations to the network's collective motions. Potentials were approximated with the use of a central force model (bond-stretching force constant) and a …

A Comparison Of Estimation Procedures For The Beta Distribution, Huey Yan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The beta distribution may be used as a stochastic model for continuous proportions in many situations in applied statistics. This thesis was concerned with estimation of the parameters of the beta distribution in three different situations.

Three different estimation procedures-the method of moments, maximum likelihood, and a hybrid of these two methods, which we call the one-step improvement-were compared by computer simulation, for beta data and beta data contaminated by zeros and ones. We also evaluated maximum likelihood estimation in the context of censored data, and Newton's method as a numerical procedure for solving the likelihood equations …

Origins Of Low-Angle Normal Faults Along The West Side Of The Bear River Range In Northern Utah, Jon E. Brummer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper presents new interpretations of two normal-slip, low-angle faults near Smithfield and Richmond, Utah. The faults have previously been interpreted as landslides, gravity slides, slide blocks, and depositional contacts. Recent work in the Basin and Range province allows new interpretations concerning the origins of the low­-angle faults.

Working hypotheses used to interpret origins of the faults are classified as folded thrust fault, rotated high-angle normal fault, gravity slide, listric normal fault, and low-angle normal fault. Among these general categories are several subhypotheses. The evaluation of each hypothesis includes a description of the geologic requirements of the hypothesis, a comparison …

Is Rainbow Trout Condition Influenced By Invertebrate-Drift Density?, Randall B. Filbert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Users of the Instream Flow Incremental Methodology CTFIM) commonly assume that there is a positive linear relationship between available habitat (WUA) and stream fish biomass. However, several studies have shown a lack cf correlation between WUA and biomass. Such poor relationships may occur if other factors limit fish abundance. Food availability is a potentially important factor limiting abundance of stream fishes and can affect blomass by influencing fish condition (individual weight). I collected rainbow trout (Oncorhynchus mykiss) exposed to different levels of invertebrate-drift density to determine if condition was greater where food was more abundant. I also examined …

Mathematical Programming Applications In Agroforestry Planning, Laurence H. Reeves

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Agroforestry as a sustainable production system has been recognized as a land use system with the potential to slow encroachment of agriculture onto forested lands in developing countries. However, the acceptance of nontraditional agroforestry systems has been hampered in some areas due to the risk-averse nature of rural agriculturalists. By explicitly recognizing risk in agroforestry planning, a wider acceptance of agroforestry is possible. This thesis consists of a collection of three papers that explore the potential of modern stock portfolio theory to reduce financial risk in agroforestry planning.

The first paper presents a theoretical framework that incorporates modern stock portfolio …

Linear Operators Strongly Preserving Polynomial Equations Over Antinegative Semirings, Sang-Gu Lee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We characterized the group of linear operators that strongly preserve r-potent matrices over the binary Boolean semiring, nonbinary Boolean semirings, and zero-divisor free antinegative semirings. We extended these results to show that linear operators that strongly preserve r-potent matrices are equivalent to those linear operators that strongly preserve the matrix polynomial equation p(X) = X. where p(X) = X^r₁ + X^r₂ + ... + X^r_t and r₁>r₂>...>r_t≥2.

In addition, we characterized the group of linear operators that strongly preserve r-cyclic matrices over the same semirings. We …

Extension Of The Metal Light Pipe Infrared Spectroscopy Technique: Applications To Surface Adsorption And High Tc Superconductors, Torsten Will

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The development of an infrared instrument for the study of surface adsorption and high T_c superconductors is presented and its applicability is discussed. The use of and theoretical background for the metal light pipe multiple-reflection technique are discussed in comparison to other infrared devices. Measurements are carried out to determine its limitations with powdered substrates as well as its sensitivity limitation for thin films. The results of the two test measurements, adsorption of CO on MgO and investigation of the energy gap of high T_c superconductors, are presented. Comparisons of the spectra with the experimental and theoretical literature …

The Effects Of Disease, Prey Fluctuation, And Clear-Cutting On American Marten In Newfoundland, Canada, Richard J. Fredrickson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Individual variation in survival and behavior of American marten (Martes americana) was studied in relation to disease, prey fluctuation, and clear-cutting from 10 January 1986 through 20 August 1987 in Newfoundland, Canada. Thirty-seven of forty marten captured on the study area were telemetered and monitored for part or all of the study.

Marten mortality was concentrated in two intervals, fall 1986 and late winter 1987. Mortality during fall 1986 was attributable to encephalitis, while marten deaths during late winter 1987 resulted from predation and starvation attributable to the prey decline. Nonsuppurative encephalitis was first detected 7 October 1986; …

A Descriptive Study Of Range Livestock Operations In The Somali Central Rangelands, Abdinasir M. Abdulle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Information on livestock operations, particularly what kind of livestock operations are practiced in the Somali central rangelands, and how these operations differ for different herders in different vegetation types and farming systems, could serve as a major tool in making management decisions. This study provides a detailed description of range livestock operations in the Somali Central Rangelands. It also answers some important management questions.

Range livestock operations were inventoried through personal interviews with the owners and herders. Data are supplemented by previous nation-wide and regional survey statistics. Herd productivity data which include herd structures, age, age-related sales, slaughters, gifts, and …

Laramide Deformation In Precambrian Granitic Rocks, Northeastern Wind River Range, Wyoming, Mark A. Dubois

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fractures and faults in the Jakey's Fork area, northeastern Wind River Range, Wyoming, caused by brittle Laramide deformation in the Precambrian granitic basement have been studied in detail at airphoto, outcrop, and thin-section scales. The study area is bounded on the south by the approximately east-west and vertical Jakey's Fork Fault and on the east by the approximately northwest-southeast and vertical Ross Lakes Fault. Both were active during Laramide deformation. Four distinct structural domains, defined by fracture pat terns and proximity to the two major faults nave emerged in this study. The areas are: 1) Along Ross Lakes Fault granite …

Irrigation Management Considering Soil Variability And Climatic Uncertainty, Dani Or

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The increase in multipurpose use of water resources, dwindling xii water supplies, and a decline in the economic viability of many agricultural operations make efficient irrigation management imperative. Soil variability and climatic uncertainty are major obstacles to efficient irrigation management due to a lack of reliable information for decision making. This study was aimed at identifying sources of uncertainty and examining methods for reducing the effects of uncertainty on irrigation scheduling schemes.

A method for spatial-temporal estimation that combines spatial information from few measurements with a physically based model of the system dynamics is proposed. The spatial phase of the …

The Effect Of Seasonal Cattle Grazing On California Bighorn Sheep Habitat Use, Melanie J. Steinkamp

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of seasonal cattle grazing on a newly reintroduced population of California bighorn sheep (Ovis canadensis californiana) in Big Cottonwood Canyon, Idaho, was studied. The hypothesis that bighorn sheep avoid cattle was tested. The issue of avoidance between bighorn sheep and livestock is arguable. Some studies have found that bighorn sheep avoid cattle while others have found no response of bighorn sheep to cattle.

Evidence was found to document the avoidance of cattle by bighorn sheep. The size of the bighorn's home range and core area decreased with the movement of cattle into areas of high bighorn …

Soil Temperature Influence On Water Use And Yield Under Variable Irrigation, Jon M. Wraith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The need for efficient use of water resources has increased the importance of optimum soil water usage in agricultural systems. Soil temperature has been shown to be important in influencing the early development of many plant species. Many agricultural regions have suboptimal soil temperature regimes for plant growth, and some cultural practices have been shown to reduce near-surface soil temperatures. The seasonal influence of soil temperature on soil water extraction and aboveground and belowground plant growth under variable irrigation was investigated at the USU Greenville Farm in Logan, UT. Soil surface mulches and buried heat cables were used to modify …

A Study Of Denitrosation Of N-Nitroso Compounds By Irradiation With Long-Wavelength Uv Light, Zhenyu J. Wang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

N-Nitrosamines and N-nitrosamides have been reported to be mutagenic. N-Nitrosamides are direct mutagens that need no activation to be mutagenic, whereas N-nitrosamines need to be enzymatically activated to exert their mutagenicity. Oxidative demethylation of nitrosamines is a commonly accepted activation mechanism. Another pathway of nitroso compounds, denitrosation, has recently been proposed. The mechanism of denitrosation, however, is still unknown.

The purpose of this study was to use a photo -reaction model to explore the possible denitrosation mechanism of N-nitroso compounds. An N-nitrosamine, N-nitrosomorpholi ne (NMOR), and an N-nitrosamide, N-methyl-N'-nitrosoguanidine (MMNG), were irradiated with long-wavelength UV light in the presence of …

Root Exploitation Of Fertile Soil Microsites, Robert B. Jackson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Root exploitation of enriched soil microsites was examined for the tussock grasses Agropyron desertorum and Agropyron spicatum and the shrub Artemisia tridentata. Two mechanisms of exploitation of the microsites were examined: root proliferation and changes in nutrient uptake capacity. One day after nutrient solution was applied to small soil patches, the mean relative growth rate of Agropyron desertorum roots in enriched patches was two to four times greater than for roots of the same plants in soil patches treated with distilled water. This rapid and striking root proliferation occurred in response to N-P-K enrichment as well as to P or …

Using Computer Imaging To Assess Visual Impacts Of Forest Insect And Disease Pests, Daniel Rabin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Forest insect and disease pests alter the appearance of trees, thereby impacting visual resources. Because of the complexity of most forest landscapes, the degree of visual impact of pest-infested forest stands is difficult to quantify.

This paper describes a method of measuring visual impacts of pest-infested forest stands. Photographs of healthy Ponderosa pine trees were entered into a computer video-image-processing system. Using this system, images of trees were altered to simulate different degrees of infestation by limb rust, a forest pathogen.

The altered and unaltered images were shown to groups of observers who rated the scenes in terms of "scenic …

Modeling Forest Dynamics Based On Stand Level Resource Allocation, Geoffrey Candler Poole

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An ecologically based model of forest succession is presented. In the model, trees compete for a share of limited growth resources available from their environment. Competition is reflected by each tree's effect on the resource pool and is not explicitly modeled. Model parameters were fit to field data from subalpine forests of the Rocky Mountains. A technique for estimating model parameters from understory-tolerance rankings and silvical characteristics of each species is also presented. The model's output was consistent with our current understanding of forest dynamics. Emergent properties of the model also mimicked natural processes such as self-thinning, release, and maximum …

Management, Foraging Behavior, Diet Composition And Forage Quality Of Free-Ranging But Herded Camels In Ceeldheer District, Central Somalia, Ahmed A. Elmi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In Somalia, camel (Camelus dromedarius) survivability and milk production has been higher than for other domestic livestock and contributes substantially to the subsistence of Somali pastoralists. The objective of this research was to study management, foraging behavior and nutrition of camels in their natural habitat to determine how production continues under seasonal nutritional stress.

Management systems of Ceeldheer pastoralists are based on available natural pasture and water. The natural rotation grazing system maintained an ecological equilibrium in the District.

Pastoralists manipulate their herds to suit existing environmental conditions, family needs and labor availability for herding. In herd management, …

Footwall Deformation And Structural Analysis Of The Footwall Of The Willard Thrust Fault, Northern Wasatch Range, Utah, Douglas Scott Neves

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Deformation mechanisms in the footwall of the Willard thrust fault, northern Wasatch Range, Utah, change from dominantly plastic to dominantly cataclastic (both microscopically and macroscopically) in the Ophir Formation and Maxfield Limestone before the thrust begins to ramp laterally upsection southward, just to the north of the North Ogden Canyon field area. This transition in compressional deformation style and mechanism is located within a lateral distance of 3.2-kilometers along the 22-kilometer long trace of the thrust fault.

Between Willard Canyon and North Ogden Canyon penetrative deformation is localized within 200 meters of the thrust surface and is characterized by transposed …

Origin And Evolution Of Dolostone In The Middle Cambrian Langston Formation, Northern Utah, Mark C. Hall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Six major generations of dolomite are present within the Cambrian Langston Formation in the Wellsville Mountains and Bear River Range of northern Utah. Identification of dolomite generations and delineation of their relative sequences are based on normal light petrography, cathodoluminescence, staining, chemistry, inferred burial history, and deformation features. The earliest stage is believed to be Middle to Late Cambrian in age. The presence of dolomite rhombs and dolomitized echinoid fragments and peloids suggests that this stage probably formed under sabkha reflux conditions. Extensive nonferroan, polymodal, nonplanar ("xenotopic") dolomite formed next under confined mixing zone conditions. A succeeding generation of pervasive …

Probability Of Discrete Failures, Weibull Distribution, Mary Jo Hansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The intent of this research and these is to describe the development of a series of charts and tables that provide the individual and cumulative probabilities of failure applying to the Weibull statistical distribution. The mathematical relationships are developed and the computer programs are described for deterministic and Monte Carlo models that compute and verify the results. Charts and tables reflecting the probabilities of failure for a selected set of parameters of the Weibull distribution functions are provided.

Groundwater Flow Systems And Thermal Regimes Near Cooling Igneous Plutons: Influence Of Surface Topography, Mark U. Birch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Previous studies of cooling igneous plutons did not consider the possible influence of sloping surface topography. Topographically-driven fluids in high relief terrain, however, are thought to interact with deep buoyancy-driven fluids to produce large lateral-flow systems up to 5 km long and 20 km long in silicic and andesitic volcanic terrain, respectively. In this study, a quantitative investigation of the interaction of topographically-driven and buoyancy-driven fluid flow is conducted through the use of a finite element numerical model to simulate the fluid flow and thermal regimes associated with a cooling igneous pluton in the presence of significant topographic relief. The …

Parameter Estimation For Generalized Pareto Distribution, Der-Chen Lin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The generalized Pareto distribution was introduced by Pickands (1975). Three methods of estimating the parameters of the generalized Pareto distribution were compared by Hosking and Wallis (1987). The methods are maximum likelihood, method of moments and probability-weighted moments.

An alternate method of estimation for the generalized Pareto distribution, based on least square regression of expected order statistics (REOS), is developed and evaluated in this thesis. A Monte Carlo comparison is made between this method and the estimating methods considered by Hosking and Wallis (1987). This method is shown to be generally superior to the maximum likelihood, method of moments and …

A Model Of Energy Expenditure In White-Tailed Jackrabbits (Lepus Townsendii) Based On Integrated Studies Of Energetics And Field Ecology, Gordon L. Rogowitz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Field and laboratory studies were conducted to develop a model of energy expenditure in a population of white-tailed jackrabbits (Lepus townsendii). Field work in southwestern Wyoming during 1985-87 showed that the breeding season commenced at snowmelt and ceased during late- July drought. Adult females reproduced relatively synchronously and produced a mean of three litters annually. Greatest fetal production occurred in the second litter period. Collections indicated a 1:1 sex ratio, few jackrabbits >2 years-old, and a density of 7 animals / km² in the population. Postnatal growth was sigmoidal, culminating in heavier adult females than males. Using …