States

Development and evaluation of high resolution quadrupole mass analyzer and an inductively coupled plasma-Mach disk (open access)

Development and evaluation of high resolution quadrupole mass analyzer and an inductively coupled plasma-Mach disk

By definition a plasma is an electrically conducting gaseous mixture containing a significant concentration of cations and electrons. The Inductively Coupled Plasma (ICP) is an electrodeless discharge in a gas at atmospheric pressure. This discharge is an excellent one for vaporizing, atomizing, and ionizing elements. The early development of the ICP began in 1942 by Babat and then by Reed in the early 1960s. This was then followed by the pioneering work of Fassel and coworkers in the late 1960s. Commercial ICP spectrometers were introduced in the mid 1970s. A major breakthrough in the area of ICP took place in the early 1980s when the ICP was shown to be an excellent ion source for mass spectrometry.
Date: December 10, 1999
Creator: Amad, Ma'an Hazem
System: The UNT Digital Library

Development of a Coaxiality Indicator

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The geometric dimensioning and tolerancing concept of coaxiality is often required by design engineers for balance of rotating parts and precision mating parts. In current practice, it is difficult for manufacturers to measure coaxiality quickly and inexpensively. This study examines feasibility of a manually-operated, mechanical device combined with formulae to indicate coaxiality of a test specimen. The author designs, fabricates, and tests the system for measuring coaxiality of holes machined in a steel test piece. Gage Repeatability and Reproducibility (gage R&R) and univariate analysis of variance is performed in accordance with Measurement System Analysis published by AIAG. Results indicate significant design flaws exist in the current configuration of the device; observed values vary greatly with operator technique. Suggestions for device improvements conclude the research.
Date: December 1999
Creator: Arendsee, Wayne C.
System: The UNT Digital Library
Examining the Nature of Interactions which Facilitate Learning and Impact Reading Achievement During a Reading Apprenticeship: A Case Study of At-risk Adolescent Readers (open access)

Examining the Nature of Interactions which Facilitate Learning and Impact Reading Achievement During a Reading Apprenticeship: A Case Study of At-risk Adolescent Readers

The purpose of this qualitative case study was to explore the interactions that take place during a reading apprenticeship which facilitate the learning of reading strategies by adolescent students who are at the middle school level and are still at-risk for reading failure and to investigate how a reading apprenticeship affects reading achievement in the areas of fluency, vocabulary development, comprehension, and the self-perception of the reader. The case study was descriptive and interpretive in nature, and examined two students, each of whom was part of a one-to-one reading apprenticeship. The researcher served as participant observer in both cases and was the teacher in each of the one-to-one reading apprenticeships. The primary data set was qualitative in nature, and elements of quantitative data were also considered. Sessions included pretesting and posttesting using the Classroom Assessment of Reading Processes (Swearingen & Allen, 1997), reading from narrative or expository books, working with words, writing, and dialoguing about the reading. Reading strategies were directly taught, modeled, and reinforced by the teacher/researcher with the goal of the students internalizing the strategies and improving their reading in the areas of fluency, vocabulary development, and comprehension, as well as improving their attitudes toward reading and their …
Date: December 1999
Creator: Arthur, Mary L.
System: The UNT Digital Library
Media Effects on the Body Shape Ideal and Bulimic Symptomatology in Males (open access)

Media Effects on the Body Shape Ideal and Bulimic Symptomatology in Males

This study investigates the impact of sociocultural mediators in relation to eating disorders among male undergraduates. Literature on eating disorders has demonstrated that a thin body shape ideal depicted in the media directly contributes to eating pathology among females, but little research has investigated the direct effects of ideal body shape images among men. The focus of the present investigation was to assess the direct effects of exposure to the ideal male body shape on men’s affect, self esteem, body satisfaction, and endorsement of U. S. societal ideals of attractiveness. In addition, the relation of these variables to bulimic symptomatology was examined. Modeling a study conducted on women (Stice & Shaw, 1994), male undergraduates between the ages of 18 to 25 participated in premeasure (N = 169) and post measure (N = 95) conditions. Participants in the post measure were randomly exposed to pictures from magazines containing either male models depicting the ideal body shape, an average body or pictures of clothing without models. Results from repeated mulitvariate analysis indicated that exposure to the ideal body shape condition did not demonstrate significant negative changes in men’s affect, self esteem, body satisfaction or endorsement of U. S. societal ideals of attractiveness. …
Date: December 1999
Creator: Barta, Jonna Lee
System: The UNT Digital Library

A Descriptive Study of Students Who Were Accepted for Admission at West Texas A&M University But Did Not Enroll

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Each year, institutions of higher education devote valuable financial and personnel resources in the hope of enhancing student recruitment and matriculation. The purpose of this study was to examine the demographic characteristics, the factors that influenced students’ decisions to apply for admission to a university, their educational intentions, and their reasons for not enrolling after they had been admitted. The subjects of the study were first-time freshmen accepted for admission to a mid-size, public, southwestern university who did not enroll for the fall 1997 semester. Statistically significant differences were found when comparing no-shows and enrolled students by gender, ethnicity, age, ACT/SAT score, and distance of their hometown from the university. There were more female no-shows, and more males enrolled than females; a greater percentage of no-shows reported the distance of their hometown to be more than 200 miles; and the mean test score for no-shows was higher. Factors important in the college selection process found to be statistically significant among the groups were: a greater percentage of Minorities than Caucasians reported the importance of the financial aid award or a scholarship offer; students living within 100 miles of the campus reported the proximity of the university as important, advice received …
Date: December 1999
Creator: Barton, Mary Edna
System: The UNT Digital Library
Characterization of electrical resistivity as a function of temperature in the Mo-Si-B system (open access)

Characterization of electrical resistivity as a function of temperature in the Mo-Si-B system

Measurements of electrical resistivity as a function of temperature from 25 to 1,500 C were conducted on polycrystalline samples in the Mo-Si-B system. Single phase, or nearly single phase, samples were prepared for the following phases: Mo{sub 3}Si, Mo{sub 5}SiB{sub 2}, Mo{sub 5}Si{sub 3}B{sub x}, MoB, MoSi{sub 2}, and Mo{sub 5}Si{sub 3}. Thesis materials all exhibit resistivity values within a narrow range(4--22 x 10{sup {minus}7}{Omega}-m), and the low magnitude suggests these materials are semi-metals or low density of states metals. With the exception of MoSi{sub 2}, all single phase materials in this study were also found to have low temperature coefficient of resistivity(TCR) values. These values ranged from 2.10 x 10{sup {minus}10} to 4.74 x 10{sup {minus}10}{Omega}-m/{degree} C, and MoSi{sub 2} had a TCR of 13.77 x 10{sup {minus}10}{Omega}-m/{degree} C. The results from the single phase sample measurements were employed in a natural log rule-of-mixtures model to relate the individual phase resistivity values to those of multiphase composites. Three Mo-Si-B phase regions were analyzed: the binary Mo{sub 5}Si{sub 3}-MoSi{sub 2} system, the ternary phase field Mo{sub 5}Si{sub 3}B{sub x}MoB-MoSi{sub 2}, and the Mo{sub 3}Si-Mo{sub 5}SiB{sub 2}-Mo{sub 5} Si{sub 3}B{sub x} ternary region. The experimental data for samples in each of …
Date: December 10, 1999
Creator: Beckman, Sarah E.
System: The UNT Digital Library

Cure Kinetics and Processing Parameters of Neat and Reinforced High Performance Epoxy Resins: Evaluation of Techniques

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Kinetic equation parameters for the curing reaction of a commercial glass fiber reinforced high performance epoxy prepreg composed of the tetrafunctional epoxy tetraglycidyl 4,4-diaminodiphenyl methane (TGDDM), the tetrafunctional amine curing agent 4,4’-diaminodiphenylsulfone (DDS) and an ionic initiator/accelerator, are determined by various thermal analysis techniques and the results compared. The reaction is monitored by heat generated determined by differential scanning calorimetry (DSC). The changes in physical properties indicating increasing conversion are followed by shifts in glass transition temperature determined by DSC and temperature-modulated DSC (TMDSC), thermomechanical (TMA) and dynamic mechanical (DMA) analysis and thermally stimulated depolarization (TSD). Changes in viscosity, also indicative of degree of conversion, are monitored by DMA. Thermal stability as a function of degree of cure is monitored by thermogravimetric analysis (TGA). The parameters of the general kinetic equations, including activation energy and rate constant, are explained and used to compare results of various techniques. The utilities of the kinetic descriptions are demonstrated in the construction of a useful time-temperature-transformation (TTT) diagram for rapid determination of processing parameters in the processing of prepregs. Copyright is held by the author, unless otherwise noted. All rights reserved. Files: Thesis.pdf Special Conditions
Date: December 1999
Creator: Bilyeu, Bryan
System: The UNT Digital Library
The Human Object: Explorations of the Figurative Toy (open access)

The Human Object: Explorations of the Figurative Toy

This Problem in Lieu of Thesis documents the thought processes that led to the completion of a series of five interactive sculptures. Each piece incorporates a part of the human body taken from its normal context and placed into the context of children's playground equipment.
Date: December 1999
Creator: Blytas, Christina
System: The UNT Digital Library
"Marvelous Accidents": The Concerto for Prepared Piano and Chamber Orchestra of John Cage (open access)

"Marvelous Accidents": The Concerto for Prepared Piano and Chamber Orchestra of John Cage

John Cage’s Concerto for Prepared Piano and Chamber Orchestra (1950-51) holds a unique position within the composer’s oeuvre as the first work based in part on chance-derived compositional procedures. Cage entered into such practice gradually, incrementally abandoning subjective taste and personal expression through the course of the work. Drawing from the philosophical framework provided by Cage’s "Lecture on Nothing" (1950) and "Lecture on Something" (c. 1951-52), this thesis explores the aesthetic foundations of the concerto and examines Cage’s compositional methodology throughout its three movements. Special attention is paid to the procedure underlying the first movement, whose analysis is based largely on the composer’s manuscript materials for the work.
Date: December 1999
Creator: Boutwell, Brett N.
System: The UNT Digital Library
Reactions and Learning as Predictors of Job Performance in a United States Air Force Technical Training Program (open access)

Reactions and Learning as Predictors of Job Performance in a United States Air Force Technical Training Program

This study is based on Kirkpatrick's (1996) four level evaluation model. The study assessed the correlation between and among three levels of data that resulted from evaluation processes used in the U.S. Air Force technical training. The three levels of evaluation included trainee reaction (Level 1), test scores (Level 2), and job performance (Level 3). Level 1 data was obtained from the results of a 20 item survey that employed a 5-point Likert scale rating. Written test scores were used for Level 2 data. The Level 3 data was collected from supervisors of new graduates using a 5-point Likert scale survey. The study was conducted on an existing database of Air Force technical training graduates. The subjects were trainees that graduated since the process of collecting and storing Levels 1 and 2 data in computerized database began. All subjects for this study graduated between March 1997 and January 1999. A total of 188 graduates from five Air Force specialties were included. Thirty-four cases were from a single course in the aircrew protection specialty area; 12 were from a single course in the munitions and weapons specialty area; and 142 were from three separate courses in the manned aerospace maintenance specialty …
Date: December 1999
Creator: Boyd, Steven W.
System: The UNT Digital Library
A Personal Documenation System for Scholars: A Tool for Thinking (open access)

A Personal Documenation System for Scholars: A Tool for Thinking

This exploratory research focused on a problem stated years ago by Vannevar Bush: "The problem is how creative men think, and what can be done to help them think." The study explored the scholarly work process and the use of computer tools to augment thinking. Based on a review of several related literatures, a framework of 7 major categories and 28 subcategories of scholarly thinking was proposed. The literature was used to predict problems scholars have in organizing their information, potential solutions, and specific computer tool features to augment scholarly thinking. Info Select, a personal information manager with most of these features (text and outline processing, sophisticated searching and organizing), was chosen as a potential tool for thinking. The study looked at how six scholars (faculty and doctoral students in social science fields at three universities) organized information using Info Select as a personal documentation system for scholarly work. These multiple case studies involved four in-depth, focused interviews, written evaluations, direct observation, and analysis of computer logs and files collected over a 3- to 6-month period. A content analysis of interviews and journals supported the proposed AfFORD-W taxonomy: Scholarly work activities consisted of Adding, Filing, Finding, Organizing, Reminding, and Displaying …
Date: December 1999
Creator: Burkett, Leslie Stewart
System: The UNT Digital Library
The Implications of National Culture on American Knowledge Work Teams: A Model of a Collaborative Corporate Culture to Support Team Functioning (open access)

The Implications of National Culture on American Knowledge Work Teams: A Model of a Collaborative Corporate Culture to Support Team Functioning

In order to remain competitive, many American businesses implement team-based work strategies. In many cases, however, teams fail in American organizations, which may be in part due to a conflict between American culture and the cooperative environment necessary for teams to function effectively. By comparing the literature regarding American culture, challenges faced by teams, and then corporate culture, it becomes evident that there are aspects of American culture that pose challenges but also that an appropriate corporate culture can mediate some areas of incompatibility. A collaborative corporate culture can induce cooperation among employees without asking employees to work in a manner that is counterintuitive, thus gaining the benefits of teams.
Date: December 1999
Creator: Bussey, Jennifer Amy
System: The UNT Digital Library

Counselor Effectiveness and Correlations With Select Demographic Variables for Masters Level Counseling Students

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Counselor education programs are charged with the responsibility to train students to be effective counselors. Despite relative consistency in academic and clinical experiences, some students are less effective than others. It was the intent of this research to investigate possible relationships which may exist between students' background and experiences and their levels of demonstrated counselor effectiveness as measured by the Counselor Rating Form - Short Version (CRF-S) and the Supervisor Rated-Counselor Interaction Analysis (SR-CIA). It was hypothesized that counselor effectiveness would be negatively correlated with prior teaching experience and level of religious participation. Data was collected using a demographic survey from masters level counseling students participating in their practicum semester. Counseling tapes from each of the participants were collected towards the end of the semester. These tapes were then rated by doctoral students using the CRF-S and the SR-CIA. The total sample size was 28. Regression analysis was used to investigate the hypotheses. Three models were constructed. The dependent variables used were scores from the CRF-S, the SR-CIA and a third comprised of a normalized composite of CRF-S and SR-CIA termed COMPOSITE. Each model used, as the independent variables, years of teaching experience, and hours of religious participation. Results from …
Date: December 1999
Creator: Calhoun, Kenneth
System: The UNT Digital Library
The Effects of Age, Sex, and Class Stratification and the Use of Health Care Services among Older Adults in the United Kingdom (open access)

The Effects of Age, Sex, and Class Stratification and the Use of Health Care Services among Older Adults in the United Kingdom

As the population ages, providing health services for the growing number of older people will become an increasingly difficult problem. In countries where the health services are provided by the government, these problems are involved with complicated issues of finance and ethics. This is the case of the National Health Service, the government institution providing health care for the citizens of the United Kingdom. Knowing what social factors influence health care usage can be a link to match usage and funding. Literature has shown that health care utilization can be predicted by social factors, as well as the medical model, and from this orientation social variables were drawn from the 1994 General Household Survey. Social factors were analyzed to determine relationships that exist between certain types of health care use and these factors. Age, sex, and class, the three main factors shown in literature to affect usage, were then analyzed to determine if services are allocated on the basis of these factors or the basis of need from illness and disability. Results of the study show that of the predisposing variables, age, sex, and class, are associated with most types of health care use. From the enabling variables, both source …
Date: December 1999
Creator: Carter, Holly R.
System: The UNT Digital Library

Precision Atomic Spectroscopy with an Integrated Electro- Optic Modulator and DBR Diode Laser at 1083nm

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We have explored the use of recently developed high speed integrated electro optic modulators and DBR diode lasers as a tool for precision laser studies of atoms. In particular, we have developed a technique using a high speed modulator as a key element and applied it to the study of the fine structure of the 23P state of atomic helium. This state has been of long standing interest in atomic physics and its study has been the aim of several recent experiments using various precision techniques. We present our method and results, which will describe a new method for determining the fine structure constant, and lead to a precision test of atomic theory.
Date: December 1999
Creator: Castillega, Jaime
System: The UNT Digital Library
Adhesion/Diffusion Barrier Layers for Copper Integration: Carbon-Silicon Polymer Films and Tantalum Substrates (open access)

Adhesion/Diffusion Barrier Layers for Copper Integration: Carbon-Silicon Polymer Films and Tantalum Substrates

The Semiconductor Industry Association (SIA) has identified the integration of copper (Cu) with low-dielectric-constant (low-k) materials as a critical goal for future interconnect architectures. A fundamental understanding of the chemical interaction of Cu with various substrates, including diffusion barriers and adhesion promoters, is essential to achieve this goal. The objective of this research is to develop novel organic polymers as Cu/low-k interfacial layers and to investigate popular barrier candidates, such as clean and modified tantalum (Ta) substrates. Carbon-silicon (C-Si) polymeric films have been formed by electron beam bombardment or ultraviolet (UV) radiation of molecularly adsorbed vinyl silane precursors on metal substrates under ultra-high vacuum (UHV) conditions. Temperature programmed desorption (TPD) studies show that polymerization is via the vinyl groups, while Auger electron spectroscopy (AES) results show that the polymerized films have compositions similar to the precursors. Films derived from vinyltrimethyl silane (VTMS) are adherent and stable on Ta substrates until 1100 K. Diffusion of deposited Cu overlayers is not observed below 800 K, with dewetting occurred only above 400 K. Hexafluorobenzene moieties can also be incorporated into the growing film with good thermal stability. Studies on the Ta substrates demonstrate that even sub-monolayer coverages of oxygen or carbide on polycrystalline …
Date: December 1999
Creator: Chen, Li
System: The UNT Digital Library
Development of highly magnetostrictive composites for applications in magnetomechanical torque sensors (open access)

Development of highly magnetostrictive composites for applications in magnetomechanical torque sensors

The objective of this work was to investigate and develop a magnetomechanical material with high magnetomechanical response and low hysteresis. This material will be used in electronic torque sensors for advanced steering systems in automobiles which will replace the costly and fuel inefficient hydraulic steering systems currently in use. Magnetostruction and the magnetomechanical effect under torsional stress of magnetostrictive composites have been investigated in the present study.
Date: December 1, 1999
Creator: Chen, Yonghua
System: The UNT Digital Library
Korean Studies in North America 1977-1996: A Bibliometric Study (open access)

Korean Studies in North America 1977-1996: A Bibliometric Study

This research is a descriptive bibliometric study of the literature of the field of Korean studies. Its goal is to quantitatively describe the literature and serve as a model for such research in other area studies fields. This study analyzed 193 source articles and 7,166 citations in the articles in four representative Korean and Asian studies journals published in North America from 1977 to 1996. The journals included in this study were Korean Studies (KS), the Journal of Korean Studies (JKS), the Journal of Asian Studies (JAS), and the Harvard Journal of Asiatic Studies (HJAS). Subject matters and author characteristics of the source articles were examined, along with various characteristics such as the form, date, language, country of origin, subject, key authors, and key titles of the literature cited in the source articles. Research in Korean studies falls within fourteen broad disciplines, but concentrated in a few disciplines. Americans have been the most active authors in Korean studies, followed closely by authors of Korean ethnicity. Monographic literature was used most. The mean age of publications cited was 20.87 and the median age of publications cited was 12. The Price Index of Korean studies as a whole is 21.9 percent. Sources …
Date: December 1999
Creator: Chun, Kyungmi
System: The UNT Digital Library

Hospitality Students' Attitudes and Behavioral Intentions toward Learning and Using Computer Technology

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Following Ajzen/Fishbein's 1980 Theory of Reasoned Action, influences of hospitality students' external variables (age, gender, university classification, and work experience) on computer attitudes, and relationships between computer attitudes and intentions to learn and use computers were tested. A sample of 412 hospitality students completed two measurements: Loyd/Gressard's 1984 Computer Attitude Scale, and Behavioral Intentions to Learn and Use Computers. Males and females had positive computer attitudes. Graduates had more positive computer attitudes. No interaction effect existed between gender and classification. No relationships existed between age and work experience on computer attitudes. Computer attitudes positively correlated with intentions to learn and use computers. Results supported the Theory of Reasoned Action. External variables partially influence attitudes and attitudes influence intentions.
Date: December 1999
Creator: Chuvessiriporn, Suttichai
System: The UNT Digital Library
X-ray absorption spectroscopy on the calcium cofactor to the manganese cluster in photosynthetic oxygen evolution (open access)

X-ray absorption spectroscopy on the calcium cofactor to the manganese cluster in photosynthetic oxygen evolution

Along with Mn, calcium and chloride ions are necessary cofactors for oxygen evolution in Photosystem II (PS II). To further test and verify whether Ca is close to the Mn cluster, the authors substituted strontium for Ca and probed from the Sr point of view for any nearby Mn. The extended X-ray absorption fine structure (EXAFS) of Sr-reactivated PS II indicates major differences between the intact and NH{sub 2}OH-treated samples. In intact samples, the Fourier transform of the Sr EXAFS shows a Fourier peak that is missing in inactive samples. This peak II is best simulated by two Mn neighbors at a distance of 3.5 Angstrom, confirming the proximity of Ca (Sr) cofactor to the Mn cluster. In addition, polarized Sr EXAFS on oriented Sr-reactivated samples shows this peak II is dichroic: large magnitude at 10 degrees (angle between the PS II membrane normal and the x-ray electric field vector) and small at 80 degrees. Analysis of the dichroism yields the relative angle between the Sr-Mn vector and membrane normal (23 degrees {+-} 4 degrees), and the isotropic coordination number for these layered samples. X-ray absorption spectroscopy has also been employed to assess the degree of similarity between the manganese …
Date: December 16, 1999
Creator: Cinco, Roehl M.
System: The UNT Digital Library
Asleep in the Arms of God (open access)

Asleep in the Arms of God

A work of creative fiction in the form of a short novel, Asleep in the Arms of God is a limited-omniscient and omniscient narrative describing the experiences of a man named Wafer Roberts, born in Jack County, Texas, in 1900. The novel spans the years from 1900 to 1925, and moves from the Keechi Valley of North Texas, to Fort Worth and then France during World War One, and back again to the Keechi Valley. The dissertation opens with a preface, which examines the form of the novel, and regional and other aspects of this particular work, especially as they relate to the postmodern concern with fragmentation and conditional identity. Wafer confronts in the novel aspects of his own questionable history, which echo the larger concern with exploitative practices including racism, patriarchy, overplanting and overgrazing, and pollution, which contribute to and climax in the postmodern fragmentation. The novel attempts to make a critique of the exploitative rage of Western civilization.
Date: December 1999
Creator: Clay, Kevin M.
System: The UNT Digital Library

Exploration of Sculpture

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The images that I sculpt deal with reflections of human traits. Wood lends itself to this endeavor, offering minimal resistance to manipulation. Keeping the origin and qualities of the material while manipulating it into another object is a statement within itself. Letting the wood do what it does naturally keeps the viewer in touch with the fact it is still just an object of nature. Wood does not make itself any less real because of the relationship of the sculpture to it as wood.
Date: December 1999
Creator: Coldewey, Charles
System: The UNT Digital Library

Empowerment: The Paradigm for Success for the Nursing Homes of the 21st Century

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For a workplace to be successful, it needs to have a higher morale, thus leading to higher quality of care for residents. For a workplace to be successful in empowerment, it must have developed strong teams, and everyone must work as a team and respect one another. The research for this paper focused on many issues. The most important part of my research came from a study of the nursing assistants at Jennings Hall (JH) in Garfield, Ohio. From the data received, I concluded that the two biggest problems in many nursing homes are lack of respect and lack of team-centered attitude.
Date: December 1999
Creator: Connorton, Margaret L.
System: The UNT Digital Library
A Narrative Herstory of Women's Studies at the University of North Texas (open access)

A Narrative Herstory of Women's Studies at the University of North Texas

In the late 1960's the academic field of Women's Studies was created to give women a more equal education and a more accurate reflection of their history and impact on society. At the University of North Texas the effort to implement Women's Studies was not begun seriously until the late 1980's. This paper covers the effort to establish Women's Studies at UNT. My thesis is that this has been a grassroots effort led by professors and students who succeeded not only in establishing Women's Studies but also in changing the face and feeling of the University, creating a more positive environment for women. The bulk of the paper is made up of narrative selections drawn from oral history interviews with key individuals.
Date: December 1999
Creator: Cook, Charles
System: The UNT Digital Library