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Adherence/Diffusion Barrier Layers for Copper Metallization: Amorphous Carbon:Silicon Polymerized Films (open access)

Adherence/Diffusion Barrier Layers for Copper Metallization: Amorphous Carbon:Silicon Polymerized Films

Semiconductor circuitry feature miniaturization continues in response to Moore 's Law pushing the limits of aluminum and forcing the transition to Cu due to its lower resistivity and electromigration. Copper diffuses into silicon dioxide under thermal and electrical stresses, requiring the use of barriers to inhibit diffusion, adding to the insulator thickness and delay time, or replacement of SiO2 with new insulator materials that can inhibit diffusion while enabling Cu wetting. This study proposes modified amorphous silicon carbon hydrogen (a-Si:C:H) films as possible diffusion barriers and replacements for SiO2 between metal levels, interlevel dielectric (ILD), or between metal lines (IMD), based upon the diffusion inhibition of previous a-Si:C:H species expected lower dielectric constants, acceptable thermal conductivity. Vinyltrimethylsilane (VTMS) precursor was condensed on a titanium substrate at 90 K and bombarded with electron beams to induce crosslinking and form polymerized a-Si:C:H films. Modifications of the films with hydroxyl and nitrogen was accomplished by dosing the condensed VTMS with water or ammonia before electron bombardment producing a-Si:C:H/OH and a-Si:C:H/N and a-Si:C:H/OH/N polymerized films in expectation of developing films that would inhibit copper diffusion and promote Cu adherence, wetting, on the film surface. X-ray Photoelectron Spectroscopy was used to characterize Cu metallization of …
Date: May 2004
Creator: Pritchett, Merry
System: The UNT Digital Library
Analysis of Leadership Perceptions Using Multirater Feedback. (open access)

Analysis of Leadership Perceptions Using Multirater Feedback.

Performance improvement intervention begins with assessment. How that assessment is interpreted can mean the difference between success and failure. Previous research of 360-degree feedback instruments has tried to reconcile the differences between multiple rater groups. Rather than searching for agreement, this research proposes to understand the meaning of the differences using multirater feedback. Individuals determine ratings based upon their own perspective and building upon the understanding of rater perspective may result in improved assessments. Data from an existing data set was processed using a second-order CFA in structural equation modeling. Covariance between the second-order factors and rater groups determined the difference in how each rater group perceived the leader.
Date: May 2004
Creator: Bradley, Thomas P.
System: The UNT Digital Library
Analysis of Perceptional Differences Among Department Chairs, Faculty, and Instructors Toward the Barrier to Using Multiple Teaching Strategies in Two-Year Technical and Community College Electronics Courses (open access)

Analysis of Perceptional Differences Among Department Chairs, Faculty, and Instructors Toward the Barrier to Using Multiple Teaching Strategies in Two-Year Technical and Community College Electronics Courses

The purpose of this study was to identify and analyze perceptional differences among department chairs, faculty, and instructors toward the barrier to using multiple teaching strategies in two-year technical and community college electronics courses. The literature review focused on defining multiple teaching strategies and identifying and discussing four major perceived barriers to implementing them in the electronics classroom: student, resources, classroom environmental, and teacher training/teaching technology. The targeted population consisted of 150 out of 231 electronics teaching technical and community college department chairs, faculty, and instructors throughout the state of Texas. In actuality, the targeted population's breakdown consisted of 36 full-time electronics teaching department chairs, 96 full-time electronics teaching faculty and instructors, and 18 part-time electronics teaching faculty and instructors who were actively involved in the delivery of instruction in their respective schools. Analysis of the data revealed that: (1) there are no significant differences among the perceptions of department chair people, faculty, and instructors toward the four perceived barriers to implementing multiple teaching strategies in a post-secondary electronics program; and (2) there are no significant differences in the perceptions electronics faculty members categorized by years teaching experience toward each of the four perceived barrier categories to implementing multiple teaching …
Date: May 2004
Creator: Hutyra, Jerry Emil
System: The UNT Digital Library
An Analysis of the Genesis of Motive, Rhythm, and Pitch in the First Movement of the Sonata for Two Pianos and Percussion by Béla Bartók. (open access)

An Analysis of the Genesis of Motive, Rhythm, and Pitch in the First Movement of the Sonata for Two Pianos and Percussion by Béla Bartók.

This dissertation presents evidence that Béla Bartók created his masterwork, the Sonata for Two Pianos and Percussion (1937), in a very complex period of his life. Since it was a mature piece, Bartók utilized typically "Bartókian" compositional techniques and styles. His ethnomusicological studies were also influential factors in the creation of the Sonata for Two Pianos and Percussion. We can be witness to how different the first draft was to the published version; the minor and major changes are revealed in the draft study of the Sonata for Two Pianos and Percussion 's first movement. These changes allow today's musicians to reconstruct the compositional process. The first movement introduces some interesting uses of sonata form, to be explored in more detail in the analysis. Starting with linear analysis, the basic motives and rhythmic patterns are discussed and supported with Bartók's own explanations. The conclusion of this study has important ramifications for performance: it eases up the pressure on the performers, since problematic passages are analyzed and explained - preparing the players' mentally for the performance. This is music which is hard to play and difficult to analyze. The analysis, combining the results of both theoretical and musicological studies, is intended …
Date: May 2004
Creator: Ujj-Hilliard, Emöke
System: The UNT Digital Library
Analysis of Web Services on J2EE Application Servers (open access)

Analysis of Web Services on J2EE Application Servers

The Internet became a standard way of exchanging business data between B2B and B2C applications and with this came the need for providing various services on the web instead of just static text and images. Web services are a new type of services offered via the web that aid in the creation of globally distributed applications. Web services are enhanced e-business applications that are easier to advertise and easier to discover on the Internet because of their flexibility and uniformity. In a real life scenario it is highly difficult to decide which J2EE application server to go for when deploying a enterprise web service. This thesis analyzes the various ways by which web services can be developed & deployed. Underlying protocols and crucial issues like EAI (enterprise application integration), asynchronous messaging, Registry tModel architecture etc have been considered in this research. This paper presents a report by analyzing what various J2EE application servers provide by doing a case study and by developing applications to test functionality.
Date: May 2004
Creator: Gosu, Adarsh Kumar
System: The UNT Digital Library
An Assessment of the Effectiveness of the CHAMPS/Life Skills Program at the University of North Texas: A Pilot Study (open access)

An Assessment of the Effectiveness of the CHAMPS/Life Skills Program at the University of North Texas: A Pilot Study

This study seeks to determine the effectiveness of the Challenging Athletes Minds for Personal Success (CHAMPS)/Life Skills program at the University of North Texas, as perceived by the student athletes who participate or participated in this program. The study attempts to measure the extent to which the student athletes feel that the program had value; if they received helpful information to support them through their college career to career transition; if the student athletes felt that the program provided them with skills to encourage better self-esteem; and if they believed that the CHAMPS/Life Skills program provided them with leadership and character education. The study, conducted in the Fall of 2003, had 163 respondents. An instrument was developed to determine student athletes' perceptions of the effectiveness of the CHAMPS/Life Skills program at UNT. The instrument consisted of 30 questions using a Likert-type scale. A Mann-Whitney U, a non-parametric t-Test, was utilized to analyze the data. This type of t-Test was used because it is specifically designed to compare the means of the same variable with two different groups and account for non-homogeneous groups. The lack of homogeneity was very likely influenced by the unequal group sizes. Generally, all aspects of the …
Date: May 2004
Creator: Goddard, Michael
System: The UNT Digital Library
Associations Between Neuromotor and Neurocognitive Functioning in Adults with Schizotypal Personality Disorder (open access)

Associations Between Neuromotor and Neurocognitive Functioning in Adults with Schizotypal Personality Disorder

Individuals diagnosed with schizotypal personality disorder (SPD) exhibit patterns of cognitive deficits in (1) attention (Lees-Roitman, Cornblatt, Bergman, Obuchowski, Mitropoulou, Keefe, Silverman, & Siever, 1997), (2) memory (Bergman, Harvey, Lees-Roitman, Mohs, Margerm, Silverman, & Siever, 1998), (3) executive functioning (Cadenhead, Perry, Shafer, & Braff, 1999), and recently (4) neuromotor functioning (Neumann & Walker, 1999), similar to individuals with a diagnosis of schizophrenia. Furthermore, recent research suggests a link between neuromotor and cognitive functioning in schizophrenia spectrum disorders (SSDs) (Neumann & Walker, 2003). The current study is an extension of research on non-drug-induced neuromotor disturbances in individuals with SPD and examines how such disturbances covary with neurocognitive measures. Approximately thirty-three adults (18-65) were rated for SPD symptoms. Motor assessments included a computerized motor task and finger tapping test. Cognitive assessments included measures of attention, verbal and visual memory, and executive functioning. Consistent with previous research, the SPD group displayed significant right hand (left hemisphere) motor disturbances (i.e., increased force and force variability) compared to healthy controls after excluding all cases reporting a history of head injury. In addition, results indicate significant associations between motor, cognitive, and symptom variables. Consistent with previous research, neuromotor functioning and the relationships between motor and cognitive …
Date: May 2004
Creator: Reynolds, Felicia D.
System: The UNT Digital Library
Bacterial Cyanide Assimilation: Pterin Cofactor and Enzymatic Requirements for Substrate Oxidation (open access)

Bacterial Cyanide Assimilation: Pterin Cofactor and Enzymatic Requirements for Substrate Oxidation

Utilization of cyanide as the sole nitrogen source by Pseudomonas fluorescens NCIMB 11764 (Pf11764) occurs via oxidative conversion to carbon dioxide and ammonia, the latter satisfying the nitrogen requirement. Substrate attack is initiated oxygenolytically by an enzyme referred to as cyanide oxygenase (CNO), which exhibits properties of a pterin-dependent hydroxylase. The pterin requirement for Pf11764 CNO was satisfied by supplying either the fully (tetrahydro) or partially (dihydro) reduced forms of various pterin compounds at catalytic concentrations (0.5 µM). These compounds included, for example, biopterin, monapterin and neopterin, all of which were also identified in cell extracts. A related CNO-mediated mechanism of cyanide utilization was identified in cyanide-degrading P. putida BCN3. This conclusion was based on (i) the recovery of CO2 and NH3 as enzymatic reaction products, (ii) the dependency of substrate conversion on both O2 and NADH, and (iiii) utilization of cyanide, O2 and NADH in a 1:1:1 reaction stoichiometry. In contrast to findings reported for Pf11764, it was not possible to demonstrate a need for exogenously added pterin as a cofactor for the PpBCN3 enzyme system. However, results which showed that cells of PpBCN3 contained approximately seven times the amount of pterin as Pf11764 (of which a significant portion …
Date: May 2004
Creator: Dolghih, Elena
System: The UNT Digital Library

Baeyer-Villiger Oxidation of 1,7- & 1,9-dibromopentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione

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Baeyer-Villiger oxidation of 1,9-dibromopentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione (1,9-dibromo-PCU-8,11-dione) was performed by using an excess amount of m-chloroperbenzoic acid (3 equivalents) and resulted in the formation of the corresponding monolactone. The reaction would not proceed to the dilactone stage. The structure of the reaction product was established unequivocally via single crystal X-ray diffraction. Baeyer-Villiger oxidation of 1,9-dibromo-PCU-8,11-dione using ceric ammonium nitrate (CAN) was also performed and afforded a mixture of lactones. Only one of these lactones, which also contained an alkene functionality, could be isolated and characterized. 1,7-dibromo-PCU-8,11-dione was also reacted with CAN, yielding the mono-lactone, which has also been characterized.
Date: May 2004
Creator: Akinola, Adeniyi O.
System: The UNT Digital Library

Bioavailability and toxicity of 2,4,6-trinitrotoluene in sediment.

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TNT (2,4,6-trinitrotoluene) is a persistent contaminant at many military installations and poses a threat to aquatic ecosystems. Data from environmental fate and toxicity studies with TNT revealed that sediment toxicity test procedures required modification to accurately assess sediment TNT toxicity. Key modifications included aging TNT-spiked sediments 8-14 d, basing lethal dose on measured sediment concentrations of the molar sum of TNT and its main nitroaromatic (NA) transformation products (SNA), basing sublethal dose on average sediment SNA concentrations obtained from integration of sediment SNA transformation models, avoiding overlying water exchanges, and minimizing toxicity test durations. Solid phase microextraction fibers (SPMEs) were investigated as a biomimetic chemical measure of toxicity and bioavailability. Both organism and SPME concentrations provided measures of lethal dose independent of exposure scenario (TNT-spiked sediment or TNT-spiked water) for Tubifex tubifex. Among all benthic organisms tested (Chironomus tentans, Ceriodaphnia dubia, T. tubifex) and matrixes, median lethal dose (LC50) estimates based on SPME and organism concentrations ranged from 12.6 to 55.3 mmol SNA/ml polyacrylate and 83.4 to 172.3 nmol SNA/g tissue, ww, respectively. For Tubifex, LC50s (95% CI) based on SNA concentrations in sediment and SPMEs were 223 (209-238) nmol SNA/g, dw and 27.8 (26.0-29.8) mmol SNA/ml, respectively. Reproductive effects …
Date: May 2004
Creator: Conder, Jason M.
System: The UNT Digital Library

Biogeography of Montane Mammals on the Colorado Plateau and Adjacent Regions

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This study identifies the biogeographic factors that structure small mammal communities on mountains of the Colorado Plateau and adjacent regions. Forty six isolated ranges were characterized across a 5-state study area encompassing the Colorado Plateau, including the central high plateaus of Utah and the Basin and Range Province (i.e. the Great Basin and mountains of Arizona and New Mexico). Presence/absence data of 25 montane mammal species were used to explore the interactions between historical and ecological processes affecting local and regional diversity patterns. Multivariate analyses, such as non-metric dimensional scaling, were used to explore factors which influence community composition. Results of these analyses revealed the Colorado River as a significant biogeographic barrier that affects montane mammal community structure. MtDNA cytochrome b sequence variation was analyzed among populations of the long-tailed vole, Microtus longicaudus, sampled from five interior ranges of the Colorado Plateau- Abajo, LaSal, Henry, and Chuska Mts., and Boulder Mountain of the Aquarius Plateau-and analyzed using traditional phylogenetic approaches (parsimony and likelihood) as well as nested clade analysis. Results support previous documentation of a major east-west phylogeographic break occurring between populations southeast of the Colorado River (eastern Arizona, Colorado, Wyoming and New Mexico) and all other western populations, which …
Date: May 2004
Creator: Carr, Carla B.
System: The UNT Digital Library

Carbon Nanotube/Microwave Interactions and Applications to Hydrogen Fuel Cells.

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One of the leading problems that will be carried into the 21st century is that of alternative fuels to get our planet away from the consumption of fossil fuels. There has been a growing interest in the use of nanotechnology to somehow aid in this progression. There are several unanswered questions in how to do this. It is known that carbon nanotubes will store hydrogen but it is unclear how to increase that storage capacity and how to remove this hydrogen fuel once stored. This document offers some answers to these questions. It is possible to implant more hydrogen in a nanotube sample using a technique of ion implantation at energy levels ~50keV and below. This, accompanied with the rapid removal of that stored hydrogen through the application of a microwave field, proves to be one promising avenue to solve these two unanswered questions.
Date: May 2004
Creator: Imholt, Timothy James
System: The UNT Digital Library

City of Denton Municipal Solid Waste Characterization and Management Strategies

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Due to concern about diminishing landfill space, the City of Denton contracted a municipal solid waste characterization study in 1999 that would identify materials for diversion. This paper describes the results of 5 1-week waste sorting events, a scale-house analysis, a recycling participation study, a recycler profile and a similar city study. The results of the characterization studies suggest that at least 50% of each waste stream is recyclable or divertible though paper products accounted for no more than 45% by weight of any waste stream. Curbside recycling participation rate was 71% during the 6-week study period though the average weekly set-out rate was 37%. Recycling participation rates varied significantly by zip code and by home value categories but not by gender. Denton is fairly progressive in its waste management approach when compared to demographically similar cities on a 15-question assessment though recommendations for improvement have been identified.
Date: May 2004
Creator: Brady, Patricia D.
System: The UNT Digital Library
Clockwork Plums (open access)

Clockwork Plums

Based on a story by Joshua Forehand with additional lyrics by Joshua Bradford, Clockwork Plums is an original musical work that integrates techniques and ideas from composers and different cultures. The accompanying essay about the work includes a summary of the story, "Clockwork Plums," some historical background covering 30 years of pop music, an analysis focusing on the use of African and Reichian compositional devices, and discussion about controlled improvisation and use of the voice as compositional tools. The music consists of three sections scored for 5 voices (lead male vocalist and SATB), flute (doubling tenor saxophone), Bb clarinet (doubling baritone saxophone), violin, cello, piano, electronic keyboard, electric guitar, electric bass, drum set, and percussion.
Date: May 2004
Creator: Bradford, Joshua
System: The UNT Digital Library
Combat Posttraumatic Stress Disorder: Effect of Intelligence on Symptomatology (open access)

Combat Posttraumatic Stress Disorder: Effect of Intelligence on Symptomatology

The objective of this study was to examine the relations between Posttraumatic Stress Disorder symptomatology and intelligence. Thirty American combat veterans of the Vietnam War, diagnosed with chronic PTSD, were given a psychodiagnostic structured interview. Participants were assessed for Intelligence Quotient as well as the veracity of their self report. The study found that there were significant differences in how participants experienced their PTSD symptoms that were correlated with intelligence. The higher IQ participants reported more frequent and intense guilt related symptoms as well as more intense intrusive recollections. The lower IQ participants experienced more frequent startle responses, more intense problems related to falling or remaining asleep and more frequent affective symptoms related to emotional numbing. Psychologists could use these differences in how PTSD is experienced in treatment planning. It may be useful for therapy to address sleep disturbances and affective numbing in lower IQ individuals. Therapy for higher IQ individuals may be more useful if it addresses feelings of guilt and intrusive recollections.
Date: May 2004
Creator: Crisp, William A.
System: The UNT Digital Library
A Comparison of the Status of Widows in Eighteenth-Century England and Colonial America. (open access)

A Comparison of the Status of Widows in Eighteenth-Century England and Colonial America.

This thesis compares the status of upper-class widows in England to Colonial America. The common law traditions in England established dower, which was also used in the American colonies. Dower guaranteed widows the right to one-third of the land and property of her husband. Jointure was instituted in England in 1536 and enabled men to bypass dower and settle a yearly sum on a widow. The creation of jointure was able to proliferate in England due to the cash-centered economy, but jointure never manifested itself in Colonial America because of the land centered economy. These two types of inheritance form the background for the argument that upper-class women in Colonial America had more legal and economical freedoms than their brethren in England.
Date: May 2004
Creator: Jones, Sarah E.
System: The UNT Digital Library
The Concept of Collision Strength and Its Applications (open access)

The Concept of Collision Strength and Its Applications

Collision strength, the measure of strength for a binary collision, hasn't been defined clearly. In practice, many physical arguments have been employed for the purpose and taken for granted. A scattering angle has been widely and intensively used as a measure of collision strength in plasma physics for years. The result of this is complication and unnecessary approximation in deriving some of the basic kinetic equations and in calculating some of the basic physical terms. The Boltzmann equation has a five-fold integral collision term that is complicated. Chandrasekhar and Spitzer's approaches to the linear Fokker-Planck coefficients have several approximations. An effective variable-change technique has been developed in this dissertation as an alternative to scattering angle as the measure of collision strength. By introducing the square of the reduced impulse or its equivalencies as a collision strength variable, many plasma calculations have been simplified. The five-fold linear Boltzmann collision integral and linearized Boltzmann collision integral are simplified to three-fold integrals. The arbitrary order linear Fokker-Planck coefficients are calculated and expressed in a uniform expression. The new theory provides a simple and exact method for describing the equilibrium plasma collision rate, and a precise calculation of the equilibrium relaxation time. It generalizes …
Date: May 2004
Creator: Chang, Yongbin
System: The UNT Digital Library
Contributions of W. A. Criswell to the Establishment and Development of The Criswell College (open access)

Contributions of W. A. Criswell to the Establishment and Development of The Criswell College

This study researched the role of W. A. Criswell as Chancellor of The Criswell College and his involvement in the areas of development, facilities acquisitions, personnel, and academics. This qualitative historical research was taken from Criswell's personal files from 1968 through 2001. W. A. Criswell gave written approval for this review and publication in November 2001. Included in Criswell's files were primary and secondary sources including copies of letters, board meeting minutes, personal notes, catalogs, newspaper articles, sermons, speeches, and other printed forms of communication. All documents pertaining to Criswell's involvement in these four categories were copied and the documents organized in chronological order, by the decade of the 1970s, the 1980s, and 1990s. Primary sources also included personal interviews and telephone interviews with eyewitnesses who were present at the events described, and board meeting minutes. Secondary sources included newspaper articles, magazine articles, national Christian magazines, and journals. Findings were summarized, evaluated and the following research questions answered (1) What was the purpose for establishing a Christian institution of higher education sponsored by First Baptist Church in Dallas, Texas? (2) What was the rationale for establishing a Christian institution of higher education in an area where a high density of …
Date: May 2004
Creator: Cowan, Gloria
System: The UNT Digital Library

A Country With No Name

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A Country With No Name is a collection of thirty-four poems with a preface explaining the style and influences of the author. The preface defends plain-language techniques in poetry, using W.H. Auden, Wislawa Szymborska, and Paul Simon as examples of poets who take a similar approach. The poems range in topic from personal and familial to societal and abstract. The main subjects encompass interpersonal relationships, romantic and otherwise, and larger concerns, such as the effects of war and modern lifestyles.
Date: May 2004
Creator: Hunziker, April
System: The UNT Digital Library

Culturing Vallisneria americana for Restoration Efforts

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Robust Vallisneria americana was cultured for restoration purposes. Preliminary studies, with various iron treatments, were conducted to ascertain the amount of phosphorous release into the water column from sediments. There was a significant difference in the amount of phosphorous released if commercial sediment was used with a low iron amendment or without an iron amendment. The second study consisted of planting V. americana on two different sediment types while supplying half of the plants with additional CO2. Plants grown on pond sediment with additional CO2 had significantly more biomass. In the third study all plants were grown on pond sediment, and half were treated with CO2. All plants that were treated with additional CO2 had significantly more biomass than those that were aerated.
Date: May 2004
Creator: Tanski, Erin M.
System: The UNT Digital Library

Cyanide Assimilation in Pseudomonas Fluorescens: Characterization of Cyanide Oxygenase as a Pterin-Dependent Multicomponent Enzyme Complex

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Cyanide utilization in Pseudomonas fluorescens NCIMB 11764 occurs via oxidative conversion to carbon dioxide and ammonia, the latter satisfying the nitrogen requirement. Substrate attack is initiated by an enzyme referred to as cyanide oxygenase (CNO), previously shown to require components in both high (H) (>30 kDa) and low (L) (<10 kDa) molecular weight cell fractions. In this study, tetrahydrobiopterin (H4biopterin) was identified as a cofactor in fraction L, thus making CNO appear as a pterin- dependent hydroxylase. CNO was purified 150-fold (specific activity 0.9 U/mg) and quantitatively converted cyanide to formate and ammonia as reaction products. When coupled with formate dehydrogenase, the complete enzymatic system for cyanide oxidation to carbon dioxide and ammonia was reconstituted. CNO was found to be an aggregate of known enzymes that included NADH oxidase (Nox), NADH peroxidase (Npx), cyanide dihydratase (CynD) and carbonic anhydrase (CA). A complex multi-step reaction mechanism is proposed in which Nox generates hydrogen peroxide which in turn is utilized by Npx to catalyze the oxygenation of cyanide to formamide accompanied by the consumption of one and two molar equivalents of oxygen and NADH, respectively. The further hydrolysis of formamide to ammonia and formate is thought to be mediated by CynD. The …
Date: May 2004
Creator: Fernandez, Ruby
System: The UNT Digital Library
Density, Distribution and Habitat Requirements for the Ozark Pocket Gopher (Geomys Bursarius Ozarkensis) (open access)

Density, Distribution and Habitat Requirements for the Ozark Pocket Gopher (Geomys Bursarius Ozarkensis)

A new subspecies of the plains pocket gopher (Geomys bursarius ozarkensis), located in the Ozark Mountains of north central Arkansas, was recently described by Elrod et al. (2000). Current range for G. b. ozarkensis was established, habitat preference was assessed by analyzing soil samples, vegetation and distance to stream and potential pocket gopher habitat within the current range was identified. A census technique was used to estimate a total density of 3, 564 pocket gophers. Through automobile and aerial survey 51 known fields of inhabitance were located extending the range slightly. Soil analyses indicated loamy sand as the most common texture with a slightly acidic pH and a broad range of values for other measured soil parameters and 21 families of vegetation were identified. All inhabited fields were located within an average of 107.2m from waterways and over 1,600 hectares of possible suitable habitat was identified.
Date: May 2004
Creator: Kershen, Audrey Allbach
System: The UNT Digital Library

Design of Power Amplifier Test Signals with a User-Defined Multisine

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Cellular radio communication involves wireless transmission and reception of signals at radio frequencies (RF). Base stations house equipment critical to the transmission and reception of signals. Power amplifier (PA) is a crucial element in base station assembly. PAs are expensive, take up space and dissipate heat. Of all the elements in the base station, it is difficult to design and operate a power amplifier. New designs of power amplifiers are constantly tested. One of the most important components required to perform this test successfully is a circuit simulator model of an entire communication system that generates a standard test signal. Standard test signals 524,288 data points in length require 1080 hours to complete one test of a PA model. In order to reduce the time taken to complete one test, a 'simulated test signal,' was generated. The objective of this study is to develop an algorithm to generate this 'simulated' test signal such that its characteristics match that of the 'standard' test signal.
Date: May 2004
Creator: Nagarajan, Preeti
System: The UNT Digital Library
A Detailed Proof of the Prime Number Theorem for Arithmetic Progressions (open access)

A Detailed Proof of the Prime Number Theorem for Arithmetic Progressions

We follow a research paper that J. Elstrodt published in 1998 to prove the Prime Number Theorem for arithmetic progressions. We will review basic results from Dirichlet characters and L-functions. Furthermore, we establish a weak version of the Wiener-Ikehara Tauberian Theorem, which is an essential tool for the proof of our main result.
Date: May 2004
Creator: Vlasic, Andrew
System: The UNT Digital Library