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Distribution and Probable Sources of Nitrate in the Seymour Aquifer, North Central Texas, USA

Description: This study utilized GIS and statistical methods to map the spatial variability of nitrate and related groundwater constituents in 30 counties above the Seymour Aquifer, analyze temporal patterns of nitrate pollution, identify probable sources of pollution, and recommend water development strategies to minimize exposure to nitrate and reduce future aquifer contamination. Nitrate concentrations in excess of 44 mg/L (US EPA limit) were commonly observed in the Seymour Aquifer region, especially in the central agricultural belt. Data indicated that this is an ongoing problem in the Seymour Aquifer and that agricultural activity and rural septic systems are the likely sources of the nitrate. Inconclusive results emphasized the need for a more comprehensive spatial and temporal water quality monitoring.
Date: May 2001
Creator: Hillin, Clifford K.

Mechanical Properties of Polymer Modified Mortar

Description: The mechanical properties of the polymer-modified mortar are markedly improved over conventional cement mortar. We utilized recycled ABS in powder form and a polymer latex emulsion, polymer percentage ranges from 0 to 25 percent by polymer/cement ratio were investigated. The mechanical properties investigated were compression strength and adhesion strength. Compression strength effects did not have an impact on adhesion strength. Adhesion strength was calculated with pullout testing apparatus designed by the author. Results indicate that recycled ABS had a lower adhesive strength than the acrylic latex emulsion and the base mortar, but did increase in adhesive strength when mixed with maleic-anhydride. The adhesive strength was investigated for a Fiber Reinforced Polymer (FRP) made of an "E" glass fiber that is a continuous strand roving oriented and pre-tensioned longitudinally in an isopthalic polyester matrix material. The FRP rebar was compared to standard steel rebars, and found that the standard steel corrugated rebar had a higher adhesive strength, due to mechanical interlocking. This was clarified by measurements using a smooth steel rebar. Characterization of the polymer-modified mortar was conducted by pore analysis and scanning electron microscopy. Scanning Electron Microscopy was implemented to view the polymer particles, the cement fibrils formed by the hydration, and to prove Ohama's theory of network structure.
Date: August 2002
Creator: Palos, Artemio

Reflections of Other/Reflections of Self

Description: This Thesis collection contains a critical preface and five stories. The preface, “Reflejos y Reflexiones” (translated: Images and Thoughts), addresses the issues of writing the cultural or gendered Other; these issues include methodology, literary colonialism, a dialogue between works, and creating distance through defamiliarizing the self. “Perennials” is the story of Noemi Tellez, an immigrant to the U.S. who must choose between working and taking care of her family. In “Load Bearing” Luis, the eldest child, faces his family and friends on one of his last days before moving away to college. “La Monarca” deals with Lily's, the youngest daughter, struggle to mediate a place between her friends and her family. In “Reflections in the River,” Arabela, the second youngest, faces the ghost of an unwanted pregnancy and La Llorona. “La Cocina de Su Madre” is the story of Magda, the oldest daughter, and her own teenage girl, Natalia, as they attempt to find themselves in a new town after moving a thousand miles from home.
Date: August 2002
Creator: Bebout, Lee

Ranges of consideration: crossing the fields of ecology, philosophy and science studies.

Description: Environmental issues are often complex with many different constituents operating according to a broad range of communication techniques. In order to foster negotiations, different perspectives need to be articulated in lucid ways sensitive to various viewpoints and circumstances. In my thesis I investigate how certain approaches to environmental discourse effect dialogue and negotiation. My first two chapters focus on environmental problems surrounding rangeland ecology along the U.S./Mexico border; whereas the last two chapters explore more theoretical conflicts concerning the philosophy of nature. Throughout the thesis I show the significance of nonhumans (prairie dogs, cattle, biological assessment sheets, environmental laws, etc.) in the human community. Only by considering the roles of nonhumans do we broaden and enrich the conversation between ourselves concerning environmental issues.
Date: December 2002
Creator: Dinneen, Nathan

A Physiological Age-Grading System for Female Hydrellia pakistanae Deonier (Diptera: Ephydridae)

Description: Conflicting opinions about the effectiveness of H. pakistanae as a biological control agent for hydrilla prompt researchers to find a method for assessing the fly's success. Developing a physiological age-grading system for the fly using ovarian morphology to detect changes in reproductive activity is useful for evaluating reproductive status of the fly in field populations. Changes in the appearance of follicular relics in ovaries with oviposition provide a reliable method to estimate fecundity. Characteristics of follicular relics were used to develop a system with eight physiological age classes, three nulliparous and five parous. Changes that occur in the fat body were used to assist in classification of nulliparous females or those with low egg counts.
Date: December 2002
Creator: Lenz, Jennifer Marie

A model for designing a new telecommunication system in Mongolia

Description: The objective of this research is to design, and determine the feasibility of, a telecommunication system for the city of Erdenet, Mongolia. The Mongolian Telecommunication Company, Telecommunication Company of Erdenet city, and the National Statistical Office of Mongolia provided the data required for telecommunication forecasting of Erdenet. The literature review and analysis of the telecommunication forecasting indicate the need for a model of a new Telecommunication system in Erdenet, Mongolia. The model, as indicated, should become a useful example for planning and updating the telecommunication system in Mongolia. The design of a proposed telecommunication network involves the following considerations: analyzing and forecasting telephone traffic, calculating the required number of channels, determining exchange locations, traffic matrix, and establishing a basic hierarchical structure.
Date: May 2001
Creator: Baatarjav, Enkhbat

Job Embeddedness as a Predictor of Voluntary Turnover: Validation of a New Instrument

Description: Voluntary turnover has become a problem for many organizations in today's society. The cost of this turnover reaches beyond organizational impact, but also affects the employees themselves. For this reason, there has been a plethora of research conducted by both academicians and practitioners on the causes and consequences of voluntary turnover. The purpose of this study is to test the validity and generalizability of the job embeddedness model of voluntary turnover to the information technology (IT) industry. The IT field has been plagued with high turnover rates in recent years. In this study, the job embeddedness model (Mitchell et al., 2001) is applied to a population sample consisting of health care information technology employees.
Date: December 2003
Creator: Besich, John S.

Comparative Bioavailability of Dietary and Dissolved Cadmium to Freshwater Aquatic Snails

Description: Heavy metal bioaccumulation in aquatic organisms may occur through direct or indirect uptake routes. Research indicates that the significance of uptake route varies with contaminant and organism exposed. The relative importance of different metal sources in aquatic systems was investigated by exposing freshwater snails to dietary or dissolved sources of cadmium. Snails were exposed to control, contaminated food only, contaminated water only, and contaminated food and water treatments. During the 15-day exposure, samples were taken to determine Cd concentration in snail soft tissue, snail shell, algal food, and overlying water. Analyses of snail soft tissue and shells indicate that exposure route significantly affects Cd concentrations in the tissues. In both cases, dissolved Cd is the primary contributor to metal body burden.
Date: December 2003
Creator: White, Jessica C.

James Earl Rudder: A Lesson in Leadership

Description: This thesis is the about the life of Rudder. The emphasis of this work, however, is that Rudder was successful primarily because of his character and leadership style. Much of the study was drawn from primary sources. Secondary sources were also consulted. This thesis opens with a brief Introduction, which discusses the need for this work. Chapter 1 discusses Rudder's life prior to WW II, emphasizing particular characteristics that benefited his leadership ability. Chapter 2 examines the 2nd Ranger Battalion's transformation under Rudder's leadership and guidance. Chapter 3 chronicles the 2nd Ranger Battalion's assault on the Pointe du Hoc battery, ending in December 1944, when Col. Rudder was reassigned to the 109th Infantry Regiment. Moreover, the controversy surrounding the Ranger's mission is also examined in this chapter. Chapter 4 describes Col. Rudder's leadership with the 109th in the Battle of the Bulge. A chapter accounting Rudder's political career and leadership follows. Chapter 6 examines his term as chancellor and president of the Texas A&M University system, until his death in 1970, and the major institutional changes that he enacted during his tenure, which resulted in A&M becoming the respected research university it is today. This significance and recapitulation of Rudder's life and leadership will follow in the Conclusion.
Date: December 2003
Creator: Bean, Christopher B.

Dead Fox Run: A Collection of Stories

Description: This collection consists of a critical preface and five linked short stories. The preface analyzes the usage of violence in literate and other forms of media, and specifically the ways in which literature can address violence without aggrandizing or stylizing it. The stories explore this idea through the lens of the lives of two young men, following them from boyhood marked by violence to adulthood crushed by the trauma of the American Civil War. Collection includes the stories "Dead Foxes," "Cow Pen," "Fatherless," "Woodsmoke," and "Brotherhood."
Date: May 2011
Creator: Starz, Andrew

Texas Annexation and the Presidential Election of 1844 in the Richmond, Virginia, and New Orleans, Louisiana, Newspaper

Description: This thesis examines the issue of Texas annexation from the viewpoints of two southern cities: Richmond, Virginia, and New Orleans, Louisiana. It looks primarily at four major newspapers, two in each city: the Richmond Enquirer and the Richmond Whig; and the New Orleans Times-Picayune and the New Orleans Whig. These four newspapers were examined thoroughly from January 1844 to July 1845. In addition to the above newspapers, the Congressional Globe and national voting patterns on Texas annexation were examined. Analysis of the editorial articles in the above newspapers offers the best possibility of understanding public sentiment toward Texas annexation and the presidential election of 1844. The evidence examined in this study indicates that Texas annexation became a decisive issue in the presidential election of 1844. It also shows that, although the press and elements within both Democratic and Whig parties were aware that the slavery question was intricately linked to the Texas annexation issue, slavery and sectional politics were not the primary factors influencing annexation. Ultimately, fundamental concerns regarding western expansion in general, especially for the Whigs, and political party loyalty proved the decisive factors in the presidential election of 1844 and Texas annexation. The evidence gathered in this study indicates that Texas annexation deliberately became an issue in the presidential election by the Democratic party. It also shows that although consideration was given to the slavery question by elements of both the Whig and Democratic parties, sectional politics did not enter into play concerning the annexation of Texas.
Date: December 2001
Creator: Short, Steven W.

Performance Evaluation of Data Integrity Mechanisms for Mobile Agents

Description: With the growing popularity of e-commerce applications that use software agents, the protection of mobile agent data has become imperative. To that end, the performance of four methods that protect the data integrity of mobile agents is evaluated. The methods investigated include existing approaches known as the Partial Result Authentication Codes, Hash Chaining, and Set Authentication Code methods, and a technique of our own design, called the Modified Set Authentication Code method, which addresses the limitations of the Set Authentication Code method. The experiments were run using the DADS agent system (developed at the Network Research Laboratory at UNT), for which a Data Integrity Module was designed. The experimental results show that our Modified Set Authentication Code technique performed comparably to the Set Authentication Code method.
Date: December 2003
Creator: Gunupudi, Vandana

Improved Approximation Algorithms for Geometric Packing Problems With Experimental Evaluation

Description: Geometric packing problems are NP-complete problems that arise in VLSI design. In this thesis, we present two novel algorithms using dynamic programming to compute exactly the maximum number of k x k squares of unit size that can be packed without overlap into a given n x m grid. The first algorithm was implemented and ran successfully on problems of large input up to 1,000,000 nodes for different values. A heuristic based on the second algorithm is implemented. This heuristic is fast in practice, but may not always be giving optimal times in theory. However, over a wide range of random data this version of the algorithm is giving very good solutions very fast and runs on problems of up to 100,000,000 nodes in a grid and different ranges for the variables. It is also shown that this version of algorithm is clearly superior to the first algorithm and has shown to be very efficient in practice.
Date: December 2003
Creator: Song, Yongqiang

When Reality Was Surreal: Lee Miller's World War II War Correspondence for Vogue

Description: During World War II, Lee Miller was an accredited war correspondent for Vogue magazine. Miller was trained as a surrealist photographer by Man Ray, and her wartime work, both photographic and written, is indicative of a combination of journalism and surrealism. This thesis examines Lee Miller's war correspondence within the context of Vogue magazine, establishing parallels between the photographs and writing to determine how surrealism informs it stylistically and ideologically. Using surrealist techniques of juxtaposition and an unmanipulated photographic style, and the surrealist concepts of the Marvelous and Convulsive Beauty, Miller presented the war as a surreality, or a surreal reality. This study concludes by using Miller's approach to suggest a new concept of journalistic practice: surrealist journalism.
Date: December 2003
Creator: Rose, Josh

Anchor Nodes Placement for Effective Passive Localization

Description: Wireless sensor networks are composed of sensor nodes, which can monitor an environment and observe events of interest. These networks are applied in various fields including but not limited to environmental, industrial and habitat monitoring. In many applications, the exact location of the sensor nodes is unknown after deployment. Localization is a process used to find sensor node's positional coordinates, which is vital information. The localization is generally assisted by anchor nodes that are also sensor nodes but with known locations. Anchor nodes generally are expensive and need to be optimally placed for effective localization. Passive localization is one of the localization techniques where the sensor nodes silently listen to the global events like thunder sounds, seismic waves, lighting, etc. According to previous studies, the ideal location to place anchor nodes was on the perimeter of the sensor network. This may not be the case in passive localization, since the function of anchor nodes here is different than the anchor nodes used in other localization systems. I do extensive studies on positioning anchor nodes for effective localization. Several simulations are run in dense and sparse networks for proper positioning of anchor nodes. I show that, for effective passive localization, the optimal placement of the anchor nodes is at the center of the network in such a way that no three anchor nodes share linearity. The more the non-linearity, the better the localization. The localization for our network design proves better when I place anchor nodes at right angles.
Date: August 2010
Creator: Pasupathy, Karthikeyan

The Effects of Response Restriction on Non-Socially Maintained Self-Injury

Description: This study examined the effects of response restriction (blocking and protective equipment) on subsequent durations of self-injury with two female participants with developmental disabilities. First, a functional analysis was conducted with each participant to identify potential maintaining variables of the self-injury. Second, access to the response was systematically restricted in a multiple schedule restriction paradigm. A baseline extended alone was conducted without the restriction component in place as a control condition. For one participant the results suggested that response restriction may have increased subsequent durations of responding once the restriction element was removed. For a second participant responding did not appear to be affected by the restriction component.
Date: May 2003
Creator: Blevins, Travis

Suppressive effects of a stimulus correlated with reprimands for automatically-maintained eye poking.

Description: A functional analysis, conducted to assess the variables maintaining the chronic eye poking of a female diagnosed with profound mental retardation, indicated that the behavior persisted in the absence of social contingencies. A procedure was initiated in a training environment in which a punisher (mild reprimand) was delivered contingent on eye poking in the presence, but not in the absence, of a neutral stimulus (wristbands). Using a combination of multiple baseline and multielement experimental designs, it was determined that that eye poking was suppressed in the presence of the previously neutral stimulus, even in environments in which the reprimand contingency was inoperative.
Date: May 2003
Creator: McKenzie, Scott Daniel

Divine and the Everyday Devil (Short Stories)

Description: Divine and the Everyday Devil contains a scholarly preface that discusses the experiences and literary works that influenced the author's writing with special attention in regards to spirituality and sexuality. The preface is followed by six original short stories. "Evil" is a work addressing a modern conception of evil. "Eschatology" concerns a man facing his own mortality. "The Gospel of Peter" tells the story of a husband grappling with his wife's religious beliefs. "The Mechanics of Projects" relates the experiences of a woman looking for love in Mexico. "The Rocky Normal Show" involves a husband growing apart from his wife and "Mutant: An Origin Story" is about a teenager trying to find his own unique identity.
Date: May 2003
Creator: Burks, T. Stephen

A parametric analysis of the immediate and subsequent effects of response restriction on hand mouthing.

Description: The immediate and subsequent effects of different durations of response restriction were evaluated in a multiple schedule design. Response restriction components of 15, 30, and 60 minutes were conducted between 15 minute alone components. Levels of responding subsequent to the termination of response restriction procedures were compared to free operant levels prior to the implementation of response restriction. Responding during response restriction components reduced to near zero levels. Subsequent levels of responding were similar to or exceeded free operant baseline levels. Results are discussed in terms of potential operant mechanisms responsible for levels of responding subsequent to response restriction.
Date: May 2003
Creator: Soderlund, Michael J.

Sex and Gender Differences in Perceived and Actual Leadership Performance: Self- and Subordinate Views

Description: The purpose of this study was to examine how male and female leaders view their own effectiveness as compared to their objective performance. This study also examined sex and gender differences in subordinate's views of male and female leaders. Forty-two mixed-sex groups led by appointed male and female leaders were observed to assess objective and perceived leader effectiveness. Gender role of participants was assessed using the Bem Sex Role Inventory (BSRI). No sex or gender differences were found in objective leadership effectiveness. An unexpected finding was that male and female leaders perceived themselves accurately as leaders. Significant differences were found in the way male subordinates rated men and women leaders when taking into account gender role. Results indicated that the study of gender bias in leadership is complex and should be examined in conjunction with gender role. Social role theory helps to explain this bias.
Date: May 2003
Creator: Rivero, Arlene Jean

Increasing the Dynamic Range of Audio THD Measurements Using a Novel Noise and Distortion Canceling Methodology

Description: The objective of this study was to determine how a new experimental methodology for measuring Total-Harmonic-Distortion (THD) of operational amplifiers functioned when compared with two standard methodologies, and whether the new methodology offers any improvement in noise floor and dynamic range along with distortion canceling of the sine-wave source used in the testing. The new methodology (THD) is being tested against two standard methodologies: Spectral Analysis using a tuned receiver type Spectrum Analyzer with Notch Filter pre-processing, and a digitized Fast Fourier Transform (FFT) using Notch Filter pre-processing. The THD results appear to agree across all methodologies, and across all items of the sample within all methodologies, to within a percent or less. The distortion and noise canceling feature of the new methodology appeared to function as expected and in accordance with theory. The sample tested in the study consisted of thirty-five NE5534 operational amplifiers produced by Texas Instruments, Inc. and purchased from a local store. The NE5534 is a low-noise, low-distortion, operational amplifier that is widely used in industry and is representative of today's best audio amplifiers.
Date: May 2003
Creator: Dunipace, Richard Alan

Characterizaton of Triethoxyfluorosilane and Tetraethoxysilane Based Aerogels

Description: Aerogels are highly porous, low dielectric constant (low k) materials being considered by the semiconductor industry as an interlayer dielectric. Low k materials are needed to overcome capacitance problems that limit device feature sizes. Precursors triethoxyfluorosilane (TEFS) and tetraethoxysilane (TEOS) were used to prepare bulk aerogels. Samples were prepared by sol-gel methods, and then carbon dioxide supercritically-dried. Effects of varying the water to precursor ratio were studied with respect to aerogel properties and microstructure. Methods of analysis for this study include FTIR-ATR, TEM, RBS, EDS, SEM, dielectric constant determination by impedance and surface area by gas adsorption. Si-F bonds were determined to be present in both acid- and base-catalyzed TEFS as well as HF-catalyzed TEOS. Fluorine promotes a fractal network microstructure as opposed to a particle-like microstructure. Surface area and dielectric constant were determined to increase slightly with increases in the water to precursor ratio.
Date: December 2001
Creator: Roepsch, Jodi Ann

Breaking Through: A Composition for Symphony Orchestra

Description: Breaking Through is a single-movement composition for symphony orchestra based on a fourteen-note melody. Every harmonic and melodic figure except the bass line is derived from this source melody. The structure of the work is based on a number of musical dichotomies that work on both local and large-scale levels. The local dichotomies contrast consonance with dissonance and ambiguity with clarity (in respect to texture and rhythm). The dichotomy of two-part form versus three-part form and the dichotomy of simplicity versus complexity operate on the large scale. The unity lended by the single source melody coupled with the contrasts furnished by the aforementioned dichotomies allow Breaking Through to be both coherent and interesting.
Date: August 2002
Creator: Dribus, John Alexander

The Relationship Between Sociometric Status of Preschool Children and Parenting Styles

Description: The purpose of the project was to examine the relationship between the social development of preschool children and parenting styles. Preschool social development was accessed by the use of sociometry. Parenting styles of mothers and fathers were determined by a questionnaire. The parenting styles and the sociometric status of the children were analyzed to determine a relationship using the chi-square analysis. The analysis indicated that there was no significant relationship between parenting styles and the sociometric status of preschool children. It is recommended that more research be done in the fields of parenting styles and sociometry.
Date: August 2002
Creator: Evans, Irene Denise