Physical Sciences and Mathematics Commons^™

Determining The Factors That Control Respiration And Carbon Use Efficiency In Crop Plants, Jonathan M. Frantz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the literature on plant respiration, there are two viewpoints concerning the source of respiratory control: supply (photosynthate availability) or demand (temperature dependent) limitations. While different studies indicate the primary dependency for respiration is either the supply or demand side, the two paradigms cannot both be true. The relative importance of each paradigm may depend on a number of factors including period of time during which respiration is measured, phase of plant development, environmental conditions, and species.

Studies were performed using continuous CO₂ gas-exchange instrumentation to monitor short- and long-term changes in whole canopies of lettuce, tomato, soybean, and …

Breeding Bird Communities Of Major Mainland Rivers Of Southeastern Alaska, Jim A. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Because of the scarcity of information for bird communities at the major mainland rivers of southeastern Alaska, the main objective of this study was to provide baseline information including distribution, status, and habitat associations of breeding birds.

I conducted a meta-analysis of all known reports (including the current study) conducted at major mainland rivers during the breeding season. I described bird species composition, distribution, abundance estimates, status, habitat associations, and guild membership for all birds recorded at 11 major mainland rivers. Based on incidental observations, 170 species were recorded by all studies. Of these, 134 species were known or suspected …

The Middle Cambrian Wheeler Formation: Sequence Stratigraphy And Geochemistry Across A Ramp-To-Basin Transition, Elizabeth S. Langenburg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Middle Cambrian Wheeler Formation is interpreted as having been deposited in the shallow ramp and deeper basin environments of the House Range embayment (HRE), presumably, during a single third-order sequence. In the Drum Mountains, the Wheeler Formation (295 m thick) is dominated by proximal and distal ramp deposits; at Marjum Pass, the Wheeler Formation (190m thick) is dominated by basinal shale deposits. The Wheeler Formation contains only one biozone marker; the first appearance of Ptyhagnostus atavus. Lack of other chronostratigraphic markers and distinctive stratal patterns in the basinal facies makes correlation along this ramp-to-basin transect difficult. Therefore, carbon-isotope …

Factors Affecting The Harvest Vulnerability Of Trumpeter Swans, Heidi L. Tangermann

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two species of swan are regularly found in Utah, tundra swans (Cygnus columbianus) and trumpeter swans (Cygnus buccinator). Tundra swans migrate through Utah. During the fall migration period they are hunted in the state under guidelines established by the United States Fish and Wildlife Service (USFWS). Trumpeter swans are occasional visitors to Utah during the same migration period. Because trumpeter swans are difficult to distinguish from tundra swans in flight, they 11 are at risk of being harvested during the swan hunt. In my thesis, I examine the factors that may influence trumpeter swan vulnerability to …

A Macroterrain Landtype Association Classification Model For The Great Basin, Frank L. Dougher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three Macroterrain Landtype Association classification models were developed to stratify and categorize Utah's West Desert. These models approached terrain segmentation using an energy-flow paradigm from erosional to transitional to depositional landscape. One model was developed as a slope-backed deterministic model that used slope-threshold limits to discriminate between Landtype Associations. A second model was developed as a stochastic, training-data driven supervised classification, using comparative t-values to classify the landscape to the most similar landtype class. The third model was a probabilistic algorithm, which classified the landscape to the most probable class based on multiple iterations of the stochastic model. These …

The Role Of Bandgap In The Secondary Electron Emission Of Small Bandgap Semiconductors: Studies Of Graphitic Carbon, Neal E. Nickles

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The question of whether the small bandgaps of semiconductors play a significant role in their secondary electron emission properties is investigated by studying evaporated graphitic amorphous carbon, which has a roughly 0.5 eV bandgap, in comparison with microcrystalline graphite, which has zero bandgap. The graphitic amorphous carbon is found to have a 30% increase in its maximum secondary electron yield over that of two microcrystalline graphite samples with comparable secondary electron yields: highly oriented pyrolytic graphite and colloidal graphite. The potentially confounding influence of the vacuum level has been isolated through the measurement of the photoelectron onset energy of the …

Stratigraphy And Paleoecology Of The Morrison Formation, Como Bluff, Wyoming, Melissa V. Connely

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Morrison Formation at Como Bluff, Wyoming, has been historically known for containing a rich source of Late Jurassic vertebrate fossils. However, when collected, most of these fossils were not positioned into a stratigraphic or sedimentologic framework. Research shows that the Morrison Formation at Como Bluff can be divided into three members. These members can be identified by lithologic and paleontological characteristics. The lower Morrison members include the Windy Hill Member and the recently described Lake Como Member. The Windy Hill Member primarily contains near-shore marine sandstone. Megavertebrate fauna is lacking. The Lake Como Member contains illitic clay in red …

Tournament Matrices An Overview, Russel O. Carlson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The results of a round robin tournament can be represented as a matrix of zeros and ones, by ordering the players and placing a one in the (i,j) position if player i beat player j, and zeros otherwise. These matrices, called tournament matrices, can be represented by graphs, called tournament graphs. They have been the subject of much research and study, yet there have been few attempts to give a wide exposition on the subject. Those that have been done tend to focus on the graph theoretical aspects of tournaments. S. Ree and Y. Koh did write a brief …

The Stratigraphic, Sedimentologic, And Paleogeographic Evolution Of The Eocene- Oligocene Grasshopper Extensional Basin, Southwest Montana, Joseph P. Matoush

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Grasshopper basin, located in southwest Montana, is an east-tilted graben bounded by the listric Muddy-Grasshopper fault and the Meriwether Lewis fault on the eastern and western margins of the basin, respectively. This basin contains a complex stratigraphy of intertonguing facies comprised of five unconformity-bounded sequences of Tertiary alluvial, flu vial, deltaic, and lacustrine sedimentary and volcanic rocks. Sequence 1 consists of the Challis volcanic Group (Middle Eocene). The sedimentary rocks of the Medicine Lodge beds (Late Eocene-Late Oligocene) represent sequence 2 and approximately 90% of the basin-fill within Grasshopper basin. Sequence 3 consists 11 of the Sedimentary Rocks of Everson …

Sedimentology, Facies Architecture, And Reservoir Characterization Of Lacustrine Rocks, Eocene Green River And Colton Formations, Uinta Basin, Utah, Andrew W. Taylor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Outcrop and petrographic studies of the Eocene Green River and Colton formations in the Uinta basin, Utah, document the facies architecture and heterogeneity characteristic of lacustrine reservoirs. A southwest-northeast transect of Eocene strata in the Uinta basin records three main marginal lacustrine depositional environments: fluvial, deltaic, and wave-dominated. Heterogeneity exists between and within individual depositional systems.

Reservoir rocks of Outcrops One and Two (the flu vial facies of the Colton Formation and the deltaic facies of the Green River Formation, respectively) consist of 2 to 18 m thick lenticular, tabular, or undulatory channel-fill, distributary channel, and distributary mouth bar deposits …

Coyote Foraging Ecology, Vigilance, And Behavioral Cascades In Response To Gray Wolf Reintroduction In Yellowstone National Park, T. Adam Switalski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Vigilance behavior can aid in the detection of predators and may also play a role in observation of conspecifics, in food acquisition, and in the prevention of kleptoparasitism. However, in most occasions, vigilance is most important as an antipredator function. Generally, factors that increase the risk of predation also increase the amount of vigilance. We examined whether the reintroduction of the large predator, the wolf, in Yellowstone National Park (YNP) would influence coyote vigilance and foraging ecology. From December 1997 to July 2000, we collected 1743 h of coyote activity budgets. Coyote home ranges occurred within wolf territories (termed high-use …

Adoption Of Range Management Innovations By Utah Livestock Producers, Elizabeth Anne Didier

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent years have seen changes in ecological conditions, ownership patterns, and political-legal forces that affect the sustainability of Western range livestock production. Enterprise diversification and implementation of improvements are advocated as ways for ranchers to cope with marginal returns from ranching while better managing resources. However, relatively few ranchers make such substantive changes in their operations, and previous research suggests that rates of adoption may be especially low in Utah.

Using a qualitative approach, this study explored innovation adoption among Utah ranchers. During preliminary interviews with 13 key informants, commitment to traditional ranching lifestyles, the state's settlement pattern, and availability …

Geometry And Physical Properties Of The Chelungpu Fault, Taiwan, And Their Effect On Fault Rupture, Richard V. Heermance

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rupture of the Chelungpu fault during the September 21, 1999, 7.6 M_wearthquake in Taiwan caused a 90-Jr,m-long surface rupture with variable displacement along strike. Analysis of core from two holes drilled through the fault zone, combined with geologic mapping and detailed investigation from three outcrops, define the fault geometry and physical properties of the Chelungpu fault in its northern and southern regions. In the northern region, the fault dips 45-60° east parallel to bedding and consists of a narrow (1-20 cm) core of dark-gray, sheared clay gouge at the base of a 30-50 m zone of increased fracture …

Relationships Between Tributary Catchments, Valley-Bottom Width, Debris-Fan Area, And Mainstem Gradient On The Colorado Plateau: A Case Study In Desolation And Gray Canyons On The Green River, Caroline M. Elliott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The alluvial forms of the rivers that drain the Colorado Plateau are a product of the water and sediment load that tributaries deliver to the trunk streams. Where the Green and Colorado Rivers cross structural barriers, narrow canyons have been incised. In the steep terrain adjacent to many of these canyons debris flows occur in the catchment basins of tributaries and deliver coarse sediment to the mainstem river corridor. Over time, debris flow deposits have aggraded in trunk stream valleys and created landforms known as debris fans. The sizes of these debris fans are related to the accommodation space available …

Geology Of The Cuesta Ridge Ophiolite Remnant Near San Luis Obispo, California: Evidence For The Tectonic Setting And Origin Of The Coast Range Ophiolite, Cameron A. Snow

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Cuesta Ridge ophiolite is one of the best-preserved remnants of mid-Jurassic ophiolite in California. Geologic mapping and petrologic studies show that it comprises (1) harzburgite mantle tectonite, (2) dunite-rich mantle transition zone (MTZ), (3) wehrlite and pyroxenite, (4) isotropic gabbro, (5) sheeted dike/sill complex, (6) volcanic rocks (7) late-stage dikes and flows, and (8) tuffaceous radiolarian chert.

The sheeted dike/sill complex is dominated by quartz diorite, with significant modal quartz and hornblende. The volcanic section is dominated by arc tholeiite and boninitic lavas. Boninites, with high MgO, Cr, and Ni comprise 40% of the volcanic rocks. Latestage dikes and …

Structural And Kinematic Evolution Of Eocene-Oligocene Grasshopper Extensional Basin, Southwest Montana, Julie C. Kickham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Grasshopper basin of southwest Montana is a complex east-dipping graben containing five unconformity-bounded sequences of Tertiary sedimentary rocks. The Eocene-Oligocene basin lies within the northern Rocky Mountain Basin and Range province. Geologic mapping in five and a half 7.5 minute quadrangles indicates that at least three distinct phases of extension characterize the Cenozoic tectonic evolution of Grasshopper basin from approximately 46 Ma to < Ma.

The significant phases of extension in Grasshopper basin were phases 1 and 3. During the first phase of extension (46-27 Ma) the nonplanar Muddy-Grasshopper fault was initiated and 90% of the basin fill was deposited. At …

Application Of Biophysical Data To An Unsupervised Classification To Map Ecoregional Boundaries In The Desert Southwest, Paxton R. Mcclurg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An unsupervised classification was applied to continuous biophysical variables in an attempt to delineate ecoregional boundaries in the desert southwest. Output was then compared with ecoregions delineated by the Natural Resources Conservation Service (NRCS), the Environmental Protection Agency (EPA), and the Forest Service at the national level. An attempt was made to use the same biophysical variables for input into the unsupervised classification as was emphasized by the various agencies with their ecoregional classifications at the desert level. Major constraints included data availability at such a large study area, data resolution, and data that were continuous. This eliminated categorical data …

Evolution Of A Miocene-Pliocene Low-Angle Normal-Fault System In The Southern Bannock Range, Southeast Idaho, Stephanie M. Carney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Geologic mapping, basin analysis, and tephrochronologic analysis in the Clifton quadrangle of southeast Idaho indicates that the modern Basin-and-Range topography is only a few million years old and that the bulk of Cenozoic extension was accommodated by slip on an older low-angle normal-fault system, the Bannock detachment system. The detachment system was active between ~12 and < 4 Ma and accommodated ~50 % extension.

Cross-cutting relationships show that the master detachment fault, the Clifton fault, is the youngest low-angle normal fault of the system, was active at a low angle, and has not been rotated to a low-dip angle through time. Map patterns and relationships indicate that the …

Nonlinear Schrödinger Type Equations With Asymptotically Linear Terms, Francois A. Van Heerden

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We study the nonlinear Schrödinger type equation

–Δu + (λg(x) + 1)u = f(u)

on the whole space R^N. The nonlinearity f is assumed to be asymptotically linear and g(x) ≥ 0 has a potential well. We do not assume a limit for g(x) as |x| → ∞ . Using variational techniques, we prove the existence of a positive solution for λ large. In the case where f is odd we obtain multiple pairs of solutions. The limiting behavior of solutions as λ → ∞ is also considered.

Ecology Of Treeline Whitebark Pine (Pinus Albicaulis) Populations In Central Idaho: Successional Status, Recruitment, And Mortality, And A Spring Temperature Reconstruction From Whitebark Pine Tree Rings, Dana Lee Perkins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research investigated the successional status of treeline whitebark pine (Pinus albicaulis) populations on 14 stands in central Idaho and used empirical statistical models to determine the principal factors affecting recruitment and mortality. The longest lived whitebark pines from four additional high-elevation sites were used to develop a tree-ring chronology to reconstruct over 1,000 years of average April-May temperature.

The assessment of stand structures using size-frequency distributions generally provides evidence that treeline whitebark pine populations are currently self-sustaining in areas of low to nonexistent incidence of white pine blister rust (Cronartium ribicola). However the presence of …

Controls On Channel Organization And Morphology In A Glaciated Basin In The Uinta Mountains, Utah, Betty E. Paepke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The organization and morphology of Middle Fork Sheep Creek and South Fork Sheep Creek, two mountain streams in the upper Sheep Creek basin, are controlled by the spatial distribution of glacial moraines. Both channels are organized into a reoccurring sequence of steep-gradient reaches changing downstream to low-gradient reaches. Steep-gradient reaches are located where the channels flow through moraine s. Low-gradient reaches are located in meadows downstream of the steep-gradient reaches and immediately upstream of the next moraine. Knickpoints in the longitudinal profiles of both streams coincide with the location of moraines.

Large boulder s, beyond the size transportable by the …

Intensification In A Risky Environment: The Case Of Improving Private Grazing Land For Beef Production In Utah, Louise D. Sainsbury

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utah ranchers commonly face risks to their livelihoods. The objective of this work was to determine if ranchers could make profitable improvements to private land forage given the combined threat of low beef prices, drought, and possible loss of public grazing.

We used linear programming (LINDO) to identify the most profitable solutions for private land investment with an 11-year simulation. Operations were divided into small, medium, and large size classes. Various forage improvements and public permits were options. Two phases of a beef price cycle (peak and trough) and 2 precipitation patterns (wet and drought) were combined as joint favorable …

Experimental Investigation Of Snapover: The Sudden Increase Of Plasma Current Drawn To A Positively Biased Conductor When Surrounded By A Dielectric, Clint D. Thomson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Snapover is particularly relevant to Earth-orbiting spacecraft powered by high-voltage solar arrays. During snapover, the current collected by a positively biased conductor that is immersed in a plasma suddenly increases when two conditions are met: i) there is an immediately adjacent insulator; ii) the conductor exceeds a positive threshold voltage with respect to the plasma. The enhanced current develops as a consequence of the insulator, either through secondary electron (SE) emission or by material ionization. Experiments were performed to examine snapover onset potential and current collection dependence on conductor and insulator materials, conductor size and shape, sample history, biasing rate, …

The Modern Mathematics Classroom: A Collection Of Virtual Manipulatives For Teachers And Students, David Stowell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An important assumption in the implementation of the National Council of Teachers of Mathematics (NCTM) Standards 2000 is that the mathematics classroom is a place where students are actively involved in the learning process. One way to foster such a learning environment is by using manipulatives. By their nature, manipulatives make the learning of mathematics a discovery-based activity. As computer use increases in the classroom, virtual manipulatives will become more important as instructional tools. Virtual manipulatives offer advantages over their traditional versions. Most important is their dynamic nature. Their dynamic capabilities provide two main benefits. First, the number of potential …

Effects Of High Ammonium/Nitrate Ratios On Nitrification And Growth Of Wheat In Hydroponics, Dawn J. Muhlestein

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen is the only plant nutrient taken up as both a cation (NH₄⁺) and anion (NO₃^-). Nitrate is considered the "safe" form of N and NH/ is generally thought to be toxic, especially at high levels. High NH₄⁺/NO₃^- ratios are thought to be toxic because they result in a rhizosphere pH low enough to damage root membranes, induced cation deficiencies, and build-up of NH3 caused by delayed NH/ assimilation. These factors can be minimized in hydroponic culture. The objective of these studies was to quantify the effects of high …

Structural And Geochemical Analyses Of Disseminated-Gold Deposits, Bald Mountain-Alligator Ridge District, Nevada: Insights Into Fault-Zone Architecture And Its Effect On Mineralization, K. Jill Hammond

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Structural and geochemical analyses of the Top and Casino deposits, Bald Mountain-Alligator Ridge district, Nevada, were conducted to determine how structures affected gold deposition in Carlin-type deposit s. We also examined how permeability changed over time in a fault that cuts siltstone-dominated sedimentary rocks. The association of gold and related arsenic with faults at the margins of a Jurassic pluton and sedimentary rocks suggests that ore fluids migrated along faults and fracture s. Permeability of the faults changed over time within the Casino deposit, where the ore-controlling fault was a distributed conduit in the early stages of mineralization but a …

Effectiveness Of Earthen Escape Ramps In Reducing Big Game Mortality In Utah, Mary L. Hammer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One-way escape gates and earthen escape ramps are structures used to enable deer to exit the highway right-of-way along fenced roads. I compared the use of one-way escape gates and earthen escape ramps by mule deer on two highways in Utah to determine if deer exhibited a preference for either structure. Results showed that earthen escape ramps were used by mule deer 8-11 times more frequently than one-way gates. Highway mortality data suggest that the installation of the escape ramps likely reduced mortality of mule deer in both study locations, because we could not attribute reductions in mortality to decreased …

Structural Analysis And A Kink Band Model For The Formation Of The Gemini Fault Zone, An Exhumed Left-Lateral Strike Slip Fault Zone In The Central Sierra Nevada, California, Matthew A. Pachell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The structure and regional tectonic setting of an exhumed, 9.3-km long, left-lateral strike-slip fault zone eludicates processes of growth, linkage, and termination for strike-slip fault zones in granitic rocks. The Gemini fault zone is composed of three steeply dipping, southwest-striking, noncoplanar segments that nucleated and grew along preexisting joints. The fault zone has a maximum slip of 131 m and is an example of a segmented, hard-linked fault zone in which geometrical complexities of the faults and compositional variations of protolith and host rock resulted in nonuniform slip orientations, complex interactions at fault segments, and an asymmetric slip-distance profile. Regional …

Generalized Minimum Penalized Hellinger Distance Estimation And Generalized Penalized Hellinger Deviance Testing For Generalized Linear Models: The Discrete Case, Huey Yan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this dissertation, robust and efficient alternatives to quasi-likelihood estimation and likelihood ratio tests are developed for discrete generalized linear models. The estimation method considered is a penalized minimum Hellinger distance procedure that generalizes a procedure developed by Harris and Basu for estimating parameters of a single discrete probability distribution from a random sample. A bootstrap algorithm is proposed to select the weight of the penalty term. Simulations are carried out to compare the new estimators with quasi-likelihood estimation. The robustness of the estimation procedure is demonstrated by simulation work and by Hapel's α-influence curve. Penalized minimum Hellinger deviance tests …

Incorporating Technology In Mathematics Education: A Suite Of E-Activities For The Modem Mathematics Classroom, Jennifer E. Youngberg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

National studies indicate major deficiencies in students' understanding of mathematics. Research suggests that students tend to view mathematics as a set of computational rules rather than a process of discovery and a tool for problem-solving. Most students fail to grasp the concepts behind the computations.

Technology provides a partial solution to this problem. Over the past decade, computers have emerged as a powerful tool in education. Computers place the control of action in the learning process with the student. They allow students to experiment with, explore, and discover mathematics at their own pace. With computers, students can consider more examples …