Physical Sciences and Mathematics Commons^™

Asymmetric Adsorbate And Substrate Interactions In Physisorbed Systems: N2 On Graphite And Dipolar Molecules On Ionic Substrates, Teresa Ellen Burns

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Asymmetries in physisorbed systems give rise to interesting phases and phase transitions in two-dimensional (2D) monolayer and multilayer systems. The effects of asymmetric adsorbate and substrate interactions in monolayers of dipolar molecules on ionic substrates and N₂ on graphite are studied.

In the case of dipolar molecules on ionic substrates, 2D dielectric phase transitions using a modified Blume-Emery-Griffiths (BEG) model are determined theoretically. A dipole adsorbed vertically above a metal ion lattice site, and pointing up (down), is assigned a spin S=+1 (S=-1). An empty lattice site is assigned a spin S=0. Analytic solutions for both ferroelectrically and antiferroelectrically …

Effect Of Iron Binding On The Ability Of Crocidolite To Cause Dna Single-Strand Breaks, Jeanne Ann Hardy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fibrous carcinogens, such as crocidolite asbestos, are known to catalyze many of the same reactions as iron, namely O₂ consumption, generation of reduced oxygen species, and damage to DNA, such as strand breaks, and modifications of bases. Upon inhalation, fibers are also known to become coated with an iron-rich material. The mechanism by which this iron is bound to fibers in the lung is not known, and the effect of this additional iron on the reactivity of the fibers is also not well understood. The studies described here were undertaken to elucidate the abilities of crocidolite asbestos, in its …

Sedimentology And Foraminiferal Taphonomy In Siliciclastic Environments: The Northern Gulf Of California, Mexico, Liping Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Holocene sediments from intertidal and shallow subtidal zones in Bahia la Choya, Mexico exhibit significant differences based on their mineralogical content, constituent composition, textural parameters, and foraminiferal assemblages. The intertidal sediments are characterized by low calcium carbonate content, being dominated by quartz, and are moderately well sorted and coarse skewed with a fine mean grain size {M_z = 2.73 phi}. Total numbers {living and dead} of benthonic Foraminifera per ml of sediment are relatively low (12/ml) in the intertidal zones. In contrast, the subtidal sediments are characterized by high calcium carbonate content, being dominated by molluscan shell fragments, and …

The Tectonic Evolution Of The Panther Creek Half-Graben In East-Central Idaho, Brian F. Hammond

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An integrated field, petrographic, structural, and geophysical analysis of the Panther Creek half-graben (PCHG), in east-central Idaho, was undertaken to determine its tectonic origin. Two competing theories as to the origin of the PCHG exist. One suggests that it formed as part of the TransChallis fault system (TCFS), a system of northeast-trending normal faults, eruptive centers, and graben that formed in Middle Eocene time. The graben of this system are bounded by northeast-striking normal faults, and show evidence of syn-tectonic deposition of basin-filling volcanic strata. The other theory suggests that the PCHG may have evolved as a result of a …

Magnitude Of Displacement And Styles Of Deformation On The Paris And Laketown Thrust Faults, Northern Utah, Richard D. Kendrick

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Surface geology is combined with abundant industry seismic-reflection and drill­-hole data in the central Bear River Range and Bear Lake Plateau to depict the forms and interactions of the Paris-Woodruff-Willard, Laketown-Meade-Home Canyon, and Crawford thrust faults. Displacement on the Paris thrust diminished to the south, and died out in splays where displacement was transferred to the Willard thrust. West of Woodruff, Utah, splays of the Laketown thrust deformed a complex footwall imbricate of the Willard thrust. To the east, a major northeast-striking Crawford thrust splay exhibits a change in slip vectors from east to southeast. Reorientation of these slip vectors …

A Study Of Magnetic Activity Effects On The Thermospheric Winds In The Low Latitude Ionosphere, Ricardo Cruz Davila

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this thesis is to examine the effects of magnetic activity on the low latitude F-region thermospheric winds. The F-region (120-1600 km) is a partially ionized medium where O⁺ and O are the major ion and neutral species, respectively. The thermospheric winds at these altitudes are driven primarily by pressure gradient forces resulting from the solar heating during the day and cooling at night. For this study, we use measured Fabry-Perot Interferometer (FPD winds at Arequipa (16.5°S, 71.5°W) and measured FPI and Incoherent Scatter Radar (ISR) winds at Arecibo (18.6°N, 66.8°W).

Previous wind studies at Arequipa and …

An Inverse Approach To A Probability Model For Fractured Networks, Stacy G. Vail

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A common problem in science and engineering applications deals with finding information about a system where only limited information is known. One example of this problem is determining the geometry of an aquifer or oil reservoir based on well tests taken at the site. The Conditional Coding Method attacks this type of problem. This method uses the Simulated Annealing Algorithm in conjunction with a probability model which generates possible solutions based on a uniform random number list. The Annealing Algorithm generates a conditional probability distribution on all possible solutions generated by the probability model, conditioned on the observed data set. …

The Pharmacodynamics And Toxicodynamics Of Inotropic Drugs In Calves With Natural And Artificial Hearts, Scott D. Everett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Inotropic support for the failing myocardium as the therapy for congestive heart failure (CHF) is intended to achieve an increase in cardiac output via positive responses in myocardial contractility and vasodilation. A novel approach to differentiate these two responses is the use of an animal with an implanted total artificial heart (TAH). Three inotropic drugs, dobutamine, enoximone, and pimobendan, were tested in eight animals with their natural heart intact and five animals implanted with a TAH. Baseline values of the TAH and natural heart (NH) were compared to determine their hemodynamic similarities. Each of the three drugs was given randomly …

Statistical Properties And Problems In Modeling The Bolivian Foreign Exchange Market, Gover Barja

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Bolivian foreign exchange market is explained in terms of the official and parallel exchange rates. The data covers the post hyper inflationary period from 1986 to 1992. The distribution of the rate of depreciation of the official and parallel exchange rates is long tailed and strongly departs from normality due to the existence of outliers. A market interactions model of the autoregressive kind is estimated using robust regression. This procedure produces M-parameter estimates using iteratively reweighted least squares. The robust method handles well the outlier problem and at the same time it reveals the true nature of the statistical …

A Monte Carlo Simulation Of Coulomb Collisions And Wave-Particle Interactions In Space Plasma At High Latitudes, Imad Ahmad Barghouthi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Four studies were considered to simulate the ion behavior in the auroral region and the polar wind.

In study I, a Monte Carlo simulation was used to investigate the behavior of O⁺ ions that are E x B-drifting through a background of neutral O, with the effect of O⁺(Coulomb) self-collisions included. Wide ranges of the ion-to-neutral density ratio n_i / n_n and electrostatic field E were considered in order to investigate the change of ion behavior with respect to the solar cycle and altitude. For low altitudes and/or solar minimum (n_i / …

Density And Feeding Habits Of Elk And Deer In Relation To Livestock Disturbance, Kenneth Clegg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Elk (Cervus elaphus) and mule deer (Odocoileus hemionus) density and foraging behavior were monitored in conjunction with disturbance by livestock (cattle and sheep) from 1991 to 1993 at Deseret Land and Livestock property near Woodruff, Utah. Elk and deer densities declined by as much as 92% in response to introduction of livestock, while associated areas where livestock were absent did not show this response. Biting rates and bite sizes were estimated and used to determine instantaneous intake rate. These measures were similar between pastures with cattle present or absent in 1992 but differed in 1993 for …

The Response Of Five Tropical Plant Species To Natural Solar Ultraviolet-B Radiation, Peter S. Searles

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tropical regions currently receive the highest global levels of solar ultraviolet-B radiation (UV-B, 280-320 nm) even without ozone depletion. Thus, the influence of natural, present-day UV-B irradiance in the tropics was examined for five tropical species, including three native rainforest tree species and two economically important species. Solar UV-B radiation conditions were obtained vi using either a UV-B excluding plastic film or a near-ambient UV-B transmitting film in a small clearing on Barro Colorado Island (BCI), Panama (9 ° N). Significant differences were often exhibited as increased foliar UV-B absorbing compounds, increased leaf mass per area, and reduced leaf blade …

Dungpat Microenvironmental Effects On Germination And Establishment Of Crested Wheatgrass, Ghulam Akbar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Complementary greenhouse and field studies investigated the effects of ambient environmental conditions on cattle dungpat moisture, temperature, nutrient concentration, and crust formation dynamics, which in turn influence seed germination and seedling establishment in dungpats. 'Hycrest' crested wheatgrass [Agropyron desertorum (Fisch. ex Link) X A. cristatum (L.) Gaert.] was used as a representative revegetation species.

After collecting feces from Holstein steers that had been fed crested wheatgrass seeds, uniform dungpats were prepared and placed on two soil types (loam and coarse sand) in containers under three watering treatments (field capacity, 1/2 field capacity, and no water) in the greenhouse. Dungpat …

Hydrogeology And Hydrochemistry Of The East-Central Portion Of The Salt Lake Valley, Utah, As Applied To Wellhead Protection In A Confined To Semiconfined Aquifer, Jeff W. Gadt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Safe Drinking Water Act includes provisions for state wellhead protection programs which address wellhead protection areas. In Utah, these areas are called drinking water source protection (DWSP) zones. Zones Two and Three are delineated according to analytical or numerical techniques, which are based on hydrogeological and time-of-travel data, as well as recharge information, accumulated through the use of hydrogeologic and hydrochemical techniques. The primary conclusions of this research are:

1. A fence diagram and site hydrostratigraphic diagram show that the hydrogeology is more complex than previously has been thought. The principal aquifer at the target well site comprises a sequence …