You limited your search to:

  Access Rights: Public
  Partner: UNT Libraries
 Collection: UNT Theses and Dissertations
Results 4911 - 4920 of 15,901
  |   |  
Work Function Study of Iridium Oxide and Molybdenum Using UPS and Simultaneous Fowler-Nordheim I-V Plots with Field Emission Energy Distributions

Work Function Study of Iridium Oxide and Molybdenum Using UPS and Simultaneous Fowler-Nordheim I-V Plots with Field Emission Energy Distributions

Date: August 1999
Creator: Bernhard, John Michael
Description: The characterization of work functions and field emission stability for molybdenum and iridium oxide coatings was examined. Single emission tips and flat samples of molybdenum and iridium oxide were prepared for characterization. The flat samples were characterized using X-ray Photoelectron Spectroscopy and X-ray diffraction to determine elemental composition, chemical shift, and crystal structure. Flat coatings of iridium oxide were also scanned by Atomic Force Microscopy to examine topography. Work functions were characterized by Ultraviolet Photoelectron Spectroscopy from the flat samples and by Field Emission Electron Distributions from the field emission tips. Field emission characterization was conducted in a custom build analytical chamber capable of measuring Field Emission Electron Distribution and Fowler-Nordheim I-V plots simultaneously to independently evaluate geometric and work function changes. Scanning Electron Microscope pictures were taken of the emission tips before and after field emission characterization to confirm geometric changes. Measurement of emission stability and work functions were the emphasis of this research. In addition, use of iridium oxide coatings to enhance emission stability was evaluated. Molybdenum and iridium oxide, IrO2, were characterized and found to have a work function of 4.6 eV and 4.2 eV by both characterization techniques, with the molybdenum value in agreement with previous ...
Contributing Partner: UNT Libraries
An Adaptive Linearization Method for a Constraint Satisfaction Problem in Semiconductor Device Design Optimization

An Adaptive Linearization Method for a Constraint Satisfaction Problem in Semiconductor Device Design Optimization

Date: May 1999
Creator: Chang, Chih-Hui, 1967-
Description: The device optimization is a very important element in semiconductor technology advancement. Its objective is to find a design point for a semiconductor device so that the optimized design goal meets all specified constraints. As in other engineering fields, a nonlinear optimizer is often used for design optimization. One major drawback of using a nonlinear optimizer is that it can only partially explore the design space and return a local optimal solution. This dissertation provides an adaptive optimization design methodology to allow the designer to explore the design space and obtain a globally optimal solution. One key element of our method is to quickly compute the set of all feasible solutions, also called the acceptability region. We described a polytope-based representation for the acceptability region and an adaptive linearization technique for device performance model approximation. These efficiency enhancements have enabled significant speed-up in estimating acceptability regions and allow acceptability regions to be estimated for a larger class of device design tasks. Our linearization technique also provides an efficient mechanism to guarantee the global accuracy of the computed acceptability region. To visualize the acceptability region, we study the orthogonal projection of high-dimensional convex polytopes and propose an output sensitive algorithm for ...
Contributing Partner: UNT Libraries
Adjustment of Kindergarten Children through Play Sessions Facilitated by Fifth Grade Students Trained in Child-Centered Play Therapy Procedures and Skills

Adjustment of Kindergarten Children through Play Sessions Facilitated by Fifth Grade Students Trained in Child-Centered Play Therapy Procedures and Skills

Date: May 1999
Creator: Baggerly, Jennifer N. (Jennifer Nalini)
Description: This research study investigated the effectiveness of the application of child-centered play therapy procedures and skills by trained fifth grade students in play sessions with kindergarten children who had adjustment difficulties. Specifically, this research determined if play sessions with trained fifth grade students facilitated change in kindergarten children's self concept, internalizing behavior, and externalizing behavior and their parents' stress level.
Contributing Partner: UNT Libraries
An Analysis of a Title I Inclusive Middle School Program in Texas over a Three Year Period: A Case Study

An Analysis of a Title I Inclusive Middle School Program in Texas over a Three Year Period: A Case Study

Date: May 1999
Creator: Restivo, Janet DiMaria
Description: The purpose of this study was to describe a Title I inclusion program in a north Texas middle school, to evaluate the degree of its success as a high achieving program, and to analyze how closely it met the requirements of the Improving America's Schools Act of 1994. Data were collected from the learning facilitators and teachers at the middle school with the permission of the school district. This study began with extensive research on the nature of adolescents and the beliefs and characteristics of high achieving middle schools. It addressed the steps which were recommended in the literature to improve middle schools and benefit students that are at-risk of failing to master the curriculum at their grade level. The researcher concluded by reporting effective strategies being used in middle school at-risk programs. These are strategies noted by experts as successful in identified programs. The population for this study was seventh and eighth grade Title I students who attended middle school during the 1992-1993, 1993-1994, 1994-1995 and 1995-1996 school years. The data collected by the researcher are presented in two parts: the description of the Title I inclusion program; and the results of the Texas Assessment of Academic Skills tests ...
Contributing Partner: UNT Libraries
An Analysis of Program Options for Gifted Middle School Students

An Analysis of Program Options for Gifted Middle School Students

Date: May 1999
Creator: Curry, Brenda Lierin
Description: The purpose of this study was to compare three different types of programming options for identified gifted and talented middle school students.
Contributing Partner: UNT Libraries
An Analysis of Status: Women in Texas, 1860-1920

An Analysis of Status: Women in Texas, 1860-1920

Date: May 1999
Creator: Breashears, Margaret Herbst
Description: This study examined the status of women in Texas from 1860 to 1920. Age, family structure and composition, occupation, educational level, places of birth, wealth, and geographical persistence are used as the measurements of status. For purposes of analysis, women are grouped according to whether they were married, widowed, divorced, or single.
Contributing Partner: UNT Libraries
Analyzing the Financial Condition of Higher Education Institutions Using Financial Ratio Analysis

Analyzing the Financial Condition of Higher Education Institutions Using Financial Ratio Analysis

Date: May 1999
Creator: Buddy, Nancy J.
Description: The problem concerned the financial indicators used to evaluate the financial condition of the six sister higher education institutions under the authority of the Board of Regents of Oklahoma Colleges. The purposes were to determine the financial ratios that best indicate financial condition; to calculate those financial ratios for the six designated Oklahoma higher education institutions; and to evaluate and compare the financial condition of the six institutions. This study attempted to further the use of financial ratio analysis as an objective addition to subjective studies that examine an institution's definition of its mission, objectives, and goals and its own assessment of the degree to which its resources allow it to attain those goals. The data were obtained from the Integrated Postsecondary Education Data System; the financial reports were audited by independent certified public accountants and presented to the Board of Regents of Oklahoma Colleges; and John Minter Associates, Inc., provided the national norms. The set of financial ratios identified provides a means to study a single higher education institution through trend analysis and in comparison to national norms. It also works well with a sample of homogeneous institutions with interinstitutional comparison. The techniques are intended to provide a general ...
Contributing Partner: UNT Libraries
The Anglo-American Council on Productivity: 1948-1952 British Productivity and the Marshall Plan

The Anglo-American Council on Productivity: 1948-1952 British Productivity and the Marshall Plan

Date: May 1999
Creator: Gottwald, Carl H.
Description: The United Kingdom's postwar economic recovery and the usefulness of Marshall Plan aid depended heavily on a rapid increase in exports by the country's manufacturing industries. American aid administrators, however, shocked to discover the British industry's inability to respond to the country's urgent need, insisted on aggressive action to improve productivity. In partial response, a joint venture, called the Anglo-American Council on Productivity (AACP), arranged for sixty-six teams involving nearly one thousand people to visit U.S. factories and bring back productivity improvement ideas. Analyses of team recommendations, and a brief review of the country's industrial history, offer compelling insights into the problems of relative industrial decline. This dissertation attempts to assess the reasons for British industry's inability to respond to the country's economic emergency or to maintain its competitive position faced with the challenge of newer industrializing countries.
Contributing Partner: UNT Libraries
The Applicability of SERVPERF in Judging Service Quality for Biomedical Information Professionals

The Applicability of SERVPERF in Judging Service Quality for Biomedical Information Professionals

Date: May 1999
Creator: Jenkins, Sharon D. (Sharon Dezel)
Description: The applicability of SERVPERF as a tool for judging the quality of services used by biomedical information professionals was tested using standard statistical procedures. Data was gathered nationally via a combination of electronic and non-electronic forms, from Area Health Education Center (AHEC) information professionals and the results consolidated to provide information for the study. It was determined that SERVPERF was applicable in making judgements about service quality for AHEC information professionals. Their perceptions about service quality tended to have a greater influence than did their level of actual satisfaction on whether or not they planned to use a particular service in the future. There is currently no validated tool available to ascertain the quality of services offered to these valuable members of the rural health care team. This dissertation proposes to provide such a tool, and to serve as a guide or template for other professionals seeking a means to judge service quality in their own disciplines.
Contributing Partner: UNT Libraries
Assembly of Pseudomonas putida Aspartate Transcarbamoylase and Possible Roles of the PyrC' Polypeptide in the Folding of the Dodecameric Enzyme

Assembly of Pseudomonas putida Aspartate Transcarbamoylase and Possible Roles of the PyrC' Polypeptide in the Folding of the Dodecameric Enzyme

Date: May 1999
Creator: Hongsthong, Apiradee, 1970-
Description: Aspartate transcarbamoylase (ATCase) of Pseudomonas putida consists of two different polypeptides, PyrB and PyrC' (Schurr et al, 1995). The role of the PyrC' and the assembly of PyrB and PyrC' have been studied. The ATCase made in vitro of P.putida PyrB with P.putida PyrC', and of E.coli PyrB with P.putida PyrC ' were generated under two different conditions, denaturation and renaturation, and untreated. It was found that PyrC' plays a role in the enzymatic regulation by ATP, CTP and UTP. In addition to playing a role in substrate binding, the PyrB polypeptide is also involved in effector binding (Kumar et al., manuscript in preparation). The most energetically preferred form of the P.putida WT is a dodecamer with a molecular mass of 480 kDa. The ratio between the PyrB and the PyrC' is 1:1. In studies of nucleotide binding, it was discovered that the P.putida PyrB was phosphorylated by a protein kinase in the cell extract. In the presence of 20 mM EDTA, this phosphorylation was inhibited and the inhibition could be overcome by the addition of divalent cations such as Zn2+ and Mg2+. This result suggested that the phosphorylation reaction required divalent cations. In the CAD complex of eukaryotes, phosphorylations ...
Contributing Partner: UNT Libraries