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Processing Of Particle Induced X-Ray Emission (Pixe) Spectra Contrasted With Electron Probe Microanalysis, J. L. Campbell

Scanning Microscopy

PIXE (proton-induced X-ray emission) analysis and EPMA (electron probe microanalysis) give rise to similar energy-dispersive X-ray spectra, and so the processing of these spectra has common elements. Consequently approaches developed for EPMA may be of use in PIXE, one example being methodology for removing the continuous background. However various special aspects of PIXE result in a somewhat more complex problem. The range of X-ray energies of interest is wider and K X-rays of medium atomic number elements tend to be used where EPMA would rely upon their L X-rays; since the projectile penetration is much greater, matrix corrections are larger; …

On-Farm Reservoir Construction In The Grand Prairie Region Of Arkansas: An Engineering Economic Analysis, Jayson K. Harper, Richard C. Peralta, Robert N. Shulstad

Civil and Environmental Engineering Faculty Publications

No abstract provided.

Multi-Layer Structure Of Nitrogen Adsorbed On Graphite, S. K. Wang, J. C. Newton, R. Wang, H. Taub, John R. Dennison, H. Shechter

All Physics Faculty Publications

Elastic neutron diffraction has been used to study the structure and layering of nitrogen films adsorbed on the (002) surfaces of an exfoliated graphite substrate. The neutron-diffraction pattern of the fully compressed monolayer at a coverage Θ=1.67 layers and a temperature ≲11 K which we reported earlier has been reanalyzed (unity coverage corresponds to a complete layer having the commensurate √3 × √3 structure). We now find it to be consistent with a four-sublattice pinwheel structure as well as the two-sublattice herringbone structure which we found previously. Below 11 K, we infer crystallization of the bilayer at Θ between 2.6 …

Navel Orangeworm (Lepidoptera:Pyralidae) Development In Mummified, Sunburned, And Walnut Husk Fly (Diptera:Tephritidae) Damaged Walnuts, Mark Douglas Shelton

Biology

The navel orangeworm, Amyelois transitella (Walker), completed development in sunburned walnuts late in the growing season, but moths did not emerge until post-harvest. Only sunburned walnuts with undamaged kernels were suitable for larval development. Navel orangeworm infestation levels up to 38% were recorded in sunburned walnut samples from the San Joaquin Valley of California. Sunburned and green, undamaged walnut kernel temperatures averaged 4.1°C and 1.8°C higher, respectively, than orchard shade air temperature. Premature hullsplit occurred in sunburned walnuts of early and later maturity varieties. Development of U.S.D.A. culture navel orangeworm moths in mummy Payne walnuts required a mean of 621 …

Cultural Resource Inventory And Testing In The Salt Creek Pocket And Devils Lane Areas, Needles District, Canyonlands National Park, Utah, Betsy L. Tipps, Nancy J. Hewitt, P-Iii Associates, Inc.

All U.S. Government Documents (Utah Regional Depository)

This document is the final technical report on the first phase of a multiyear archeological program conducted in Canyonlands National Park. Some of the purposes of this project are to gather information for upgrading the park's interpretive program, increase the scientific understanding of Canyonlands' prehistory, and prepare a research design to guide future investigation. Archeological inventory of 4500 acres in the Needles District revealed a previously undocumented Archaic occupation and showed that Formative peoples using the area were primarily the Mesa Verde Anasazi, not the Fremont and Anasazi as previously thought. The data also indicate that prehistoric peoples used the …

Utah State University Commencement, 1989 – Main Campus, Utah State University

Commencement Programs

Ninety-Sixth Annual Commencement of Utah State University

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 …

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 …

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 …

The Effects Of A Direct Instruction Program In Fractions On Academic And Mathematics Self-Concept, William H. Lowry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The study investigated the effect of a videodisc-based, teacher-controlled, direct instruction-based program in fractions content, on self-concept. Self-concept was operationally defined as scores on a slightly modified version of Marsh's Self-Description Questionnaire (Marsh, 1988). A quasi-experimental, nonequivalent control group design was used to compare the self-report self-concept of two groups of upper elementary students (N = 337). The treatment group (n = 171) received instruction in fractions via the teacher-directed, videodisc-based, Mastering Fractions program (Systems Impact, 1986a). The control group (n = 166) received their normal grade four or grade five mathematics program, but did not include common fractions.

Differences …

Density-Dependent Convective Flow In Closed Basins, Kim L. Mccleary

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Great Basin is a region of the Basin and Range Physiographic Province, which is completely isolated hydrologically from the sea. All precipitation that falls within the Great Basin is lost from the land surface or from the surface of closed inland lakes through evapotranspiration. Playas are often found at the base of these undrained basins. This study focuses on subsurface groundwater flow patterns in closed basins. Because all discharge from the basins occurs via evapotranspiration on and near the playa, the water table of the aquifer beneath the playa is often just below the ground surface. Fluctuations of the …

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 …

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 …

An Apple Rest Model For Mild Winter Conditions, Jose Ignacio Del Real Laborde

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two areas of research are reported: an experiment on the effects of warm temperature prestratification treatments on seed dormancy and a new chill unit model.

Crabapple seeds (Malus sargentii Rehd.) were allowed to imbibe water and were given warm pretreatments at temperatures of 16, 20, 24 and 28C for periods of 3, 10, 20 or 30 days before cold stratification at 4C for 20, 40, 60, 80 or 100 days. Pretreatments resulted in increased chilling requirements for seedling emergence. A short chilling period (20 days) also altered the leaf area, shoot length, internodal length and root/shoot ratio of the …

An Assessment Of Thematic Mapper Satellite Data For Classifying Conifer Types In Northern Utah, Madeline R. Mazurski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Land-cover identification and mapping are an integral part of natural resource planning and management. Satellite imagery provides a way to obtain land cover information, particularly for large tracts of land such as those administered by federal and state agencies.

This study assesses the usefulness of the Brightness/Greenness Transformation of Landsat Thematic Mapper data for differentiating conifer forest types in northern Utah. Satellite data for the Logan Ranger District of the Wasatch-Cache National Forest were classified into 27 vegetation classes. Of these, nine were determined to be conifer classes and were used in subsequent analyses. Ten sites of each conifer class …

Chemical Evaluation And Biological Vitamin A Activity Of The Major Carotenoids In The Hybrid Carrot Beta Iii, Cynthia M. Schweitzer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Genetically enhanced high-carotene Beta III hybrid carrot was compared to a commercial carrot cultivar, Nantes Coreless, for carotene content and macronutrient composition. Beta III contained more than twice the total carotene content of Nantes Coreless, with α-carotene/β-carotene ratios higher in Beta III. Total solids from protein, lipids, and carbohydrate were greater in Beta III than in Nantes Coreless. Beta III contained about five times the amount of sucrose and one-fifth the amount of glucose and fructose than Nantes Coreless or reported literature values.

Comparison of the bioavailability of carotenes in Beta III and Nantes Coreless to purified β-carotene and retinyl …

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 …

Neuroanatomical Asymmetry, Handedness, And Family History Of Handedness: A Study Of The Markers Of Structural And Functional Lateralization, Steven A. Lifson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study investigated the associations between (1) handedness (demonstrated preference of one hand for the performance of most unimanual tasks) and neuroanatomical asymmetry (measurable differences in width between the cerebral hemispheres) and (2) familial history of handedness (the presence of a left-handed sibling or parent of a right-handed subject) as an intervening factor in the relation between handedness and neuroanatomical asymmetry. Width measurements of the brain were derived from computerized tomographic (CT) films and grouped in to categories by hand preference (measured by the Edinburgh Handedness Inventory) and family history. The measurements of right (n=68), right with left-handed relatives (n=24), …

Reaction Time In Elderly Subjects: The Effects Of Practice On Two Different Reaction Time Tasks, Dawn Marie Birk

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The reaction time of four groups of elderly human subjects were examined to determine the effects of stimulus presentation and task practice. Each group practiced different tasks, each requiring a response when more than one alternative was available. Two tasks involved making responses based on either visually or auditorily presented stimuli only. One task required decisions to be made on the basis of both auditory and visual stimuli. The fourth group acted as a comparison group and did not practice a reaction-time task; although they did perform a task on the computer and their reaction times were measured. Before and …

Incremental Returns To Cattle Feeding From Alternative Feedlot Practices, Ibrahim R. Hani

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The main goals of this study are to: 1) identify the influence of various breeds, feeds, and hormone additives on the final weight or the rate of gain of feeder cattle; 2) determine the physical relationships among breeds, feeds, hormone additives, and other variables; and 3) estimate the costs and benefits associated with alternative feed and/or hormone additives and other variables to determine whether the benefits of using different breeds, feeds, and hormone additives exceed the costs. The linear mode l was initially chosen and showed that Rumensin additive and Angus and Simmental cross breeds were not significant on the …

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.

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 …

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 …

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, …

The Vascularization Of The Skin Of The Atlantic Hagfish, Myxine Glutinosa L. As Revealed By Scanning Electron Microscopy Of Vascular Corrosion Casts, A. Lametschwandtner, T. Weiger, U. Lametschwandtner, V. Georgieva-Hanson, R. A. Patzner, H. Adam

Scanning Microscopy

The vascularization of three different (A, B, C) skin regions (from the level of the heart to the cloaca including dorsal, lateral and ventral skin areas) of the Atlantic hagfish, Myxine glutinosa L. was studied by scanning electron microscopy of vascular corrosion casts. Vessel variables were measured either from semithin sections (diameters) or from vascular corrosion casts (diameters, lengths) and total blood capacities as well as vessel surfaces per unit skin area (mm²) were calculated. There are no significant differences in the number of subepidermal capillary meshes (ranging from 164 to 185 meshes per micrograph) in areas A, …

Mapping The Wind In The Polar Thermosphere: A Case Study Within The Cedar Program, R W. Smith, J W. Meriwether, G Hernandez, R David, Vincent B. Wickwar, O De La Beaujardiere, T L. Killeen

All Physics Faculty Publications

The thermosphere is that region of neutral atmosphere in which atmospheric constituents are gravitationally bound to the Earth but are barometrically distributed according to their molecular or atomic weights. Unlike the lower atmosphere, mixing processes a reweak, which allows each constituent gas to behave independently. The thermosphere begins at about 100-km-altitude and extends up to 500 km or beyond. The temperature increases with height throughout the layer, which is a stabilizing influence.

Computational Aspects Of Chance-Constrained Sustained Groundwater Yield Management, R. R.A. Cantiller, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

A methodology for including chance-constraints in models for maximizing regional sustained-yield groundwater extraction is presented. The procedure utilizes the spatially distributed mean and variance of saturated thickness in a confined aquifer. This data is derivable from kriging, a geostatistical technique. The technique is applied to a scenario of somewhat egalitarian agricultural development dependent on groundwater. Decision makers in this situation know that groundwater availability is insufficient to supply all potential demand. They plan to implement a sustained yield groundwater extraction strategy. They know that because of uncertain knowledge of aquifer parameters, at some point in the future, available groundwater in …

Nature Of Carbon-Carbon Bonding In Evaporated And Ion-Sputtered (Diamondlike) Amorphous Carbon From (E, 2e) Spectroscopy, Chao Gao, Yun Yu Wang, A. L. Ritter, John R. Dennison

All Physics Faculty Publications

The local carbon-carbon bonding in evaporated (e-C) and ion-sputtered (i-C) amorphous carbon has been investigated by transmission electron-energy-loss spectroscopy (EELS) and by (e, 2e) spectroscopy. The EELS data indicate that the e-C is graphiclike and the i-C is diamondlike. The (e, 2e) data demonstrate that the concentration of sp² bonding is ∼100% in both materials (0.85≤c_sp²≤1.0) for e-C and 0.75≤c_sp²≤1.0 for i-C). There is significant rehybridization of the π orbital in i-C.

Modeled F Region Response To Auroral Dynamics Based Upon Dynamics Explorer Auroral Observations, Jan Josef Sojka, Robert W. Schunk, J. D. Cravens, L. A. Frank, J. Sharber, J. D. Winningham

All Physics Faculty Publications

Auroral images from the Dynamics Explorer 1 (DE 1) scanning auroral imager have been combined with in situ auroral precipitation data from the DE 2 low altitude plasma instrument to form a time-dependent global auroral energy flux model. This model has both good time (12 min) and spatial (100 km) resolution compared to that currently available for global scale ionospheric and thermospheric modeling. The development and comparison of this model with others are discussed. Data from an aurorally active period, November 25, 1981, are presented and used as a case study for this model. Using a global ionospheric model, the …

Global Scale, Physical Models Of The F Region Ionosphere, Jan Josef Sojka

All Physics Faculty Publications

During the last decade, ionospheric F region modeling has reached an accurate climatological level. We now have global computer models of the F region which simulate the interactions between physical processes in the ionosphere. Because of their complexity, these climatological models are confined to modern day supercomputers. This review focuses on the development and verification of these physical ionospheric models. Such models are distinct from local models, steady state models, and empirical models of the ionosphere, which are, by their conception, unable to represent physically the range of F region variability or storm dynamics. This review examines the limitations of …