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A simulation-based study of HighSpeed TCP and its deployment

Description: The current congestion control mechanism used in TCP has difficulty reaching full utilization on high speed links, particularly on wide-area connections. For example, the packet drop rate needed to fill a Gigabit pipe using the present TCP protocol is below the currently achievable fiber optic error rates. HighSpeed TCP was recently proposed as a modification of TCP's congestion control mechanism to allow it to achieve reasonable performance in high speed wide-area links. In this research, simu… more
Date: April 29, 2003
Creator: Souza, Evandro de
Partner: UNT Libraries Government Documents Department
open access

High-Throughput Genetic Analysis and Combinatorial Chiral Separations Based on Capillary Electrophoresis

Description: Capillary electrophoresis (CE) offers many advantages over conventional analytical methods, such as speed, simplicity, high resolution, low cost, and small sample consumption, especially for the separation of enantiomers. However, chiral method developments still can be time consuming and tedious. They designed a comprehensive enantioseparation protocol employing neutral and sulfated cyclodextrins as chiral selectors for common basic, neutral, and acidic compounds with a 96-capillary array syst… more
Date: August 5, 2003
Creator: Zhong, Wenwan
Partner: UNT Libraries Government Documents Department
open access

Geometry, topology, and string theory

Description: A variety of scenarios are considered which shed light upon the uses and limitations of classical geometric and topological notions in string theory. The primary focus is on situations in which D-brane or string probes of a given classical space-time see the geometry quite differently than one might naively expect. In particular, situations in which extra dimensions, non-commutative geometries as well as other non-local structures emerge are explored in detail. Further, a preliminary exploratio… more
Date: July 10, 2003
Creator: Varadarajan, Uday
Partner: UNT Libraries Government Documents Department
open access

Structural studies of conformational changes of proteins upon phosphorylation: Structures of activated CheY, CheY-N16-FliM complex, and AAA {sup +} ATPase domain of NtrC1 in both inactive and active states

Description: Protein phosphorylation is a general mechanism for signal transduction as well as regulation of cellular function. Unlike phosphorylation in eukaryotic systems that uses Ser/Thr for the sites of modification, two-component signal transduction systems, which are prevalent in bacteria, archea, and lower eukaryotes, use an aspartate as the site of phosphorylation. Two-component systems comprise a histidine kinase and a receiver domain. The conformational change of the receiver domain upon phosphor… more
Date: April 10, 2003
Creator: Lee, Seok-Yong
Partner: UNT Libraries Government Documents Department
open access

Maskless, resistless ion beam lithography

Description: As the dimensions of semiconductor devices are scaled down, in order to achieve higher levels of integration, optical lithography will no longer be sufficient for the needs of the semiconductor industry. Alternative next-generation lithography (NGL) approaches, such as extreme ultra-violet (EUV), X-ray, electron-beam, and ion projection lithography face some challenging issues with complicated mask technology and low throughput. Among the four major alternative NGL approaches, ion beam lithogra… more
Date: March 10, 2003
Creator: Ji, Qing
Partner: UNT Libraries Government Documents Department
open access

Patterning nanocrystals using DNA

Description: One of the goals of nanotechnology is to enable programmed self-assembly of patterns made of various materials with nanometer-sized control. This dissertation describes the results of experiments templating arrangements of gold and semiconductor nanocrystals using 2'-deoxyribonucleic acid (DNA). Previously, simple DNA-templated linear arrangements of two and three nanocrystals structures have been made.[1] Here, we have sought to assemble larger and more complex nanostructures. Gold-DNA conjuga… more
Date: September 1, 2003
Creator: Williams, Shara Carol
Partner: UNT Libraries Government Documents Department
open access

SPA-LEED Study of the Morphology and Nucleation of a Novel Growth Mode and the ''devil's staircase'' on Pb/Si(111)

Description: This thesis was developed to address the following questions for the Pb/Si(111) system: (1) Is it possible to control the nano-structure growth by changing the initial substrate; (2) is the nucleation theory applicable to the case of the 7-step growth mode; and (3) what phase or phases could be formed between coverage 6/5 ML and 4/3 ML? The first question was answered in chapter 2, different growth results were observed for different initial substrate, suggesting the possibility of controlling … more
Date: December 12, 2003
Creator: Yeh, Wang-Chi Vincent
Partner: UNT Libraries Government Documents Department
open access

Bioanalytical Applications of Real-Time ATP Imaging Via Bioluminescence

Description: The research discussed within involves the development of novel applications of real-time imaging of adenosine 5'-triphosphate (ATP). ATP was detected via bioluminescence and the firefly luciferase-catalyzed reaction of ATP and luciferin. The use of a microscope and an imaging detector allowed for spatially resolved quantitation of ATP release. Employing this method, applications in both biological and chemical systems were developed. First, the mechanism by which the compound 48/80 induces rel… more
Date: December 12, 2003
Creator: Gruenhagen, Jason Alan
Partner: UNT Libraries Government Documents Department
open access

VE-Suite: Coupling Visualization and Computational Environments to Support on-the-fly Engineering Design

Description: CFD (Computational Fluid Dynamics) is a widely used technique in engineering design field. It uses mathematical methods to simulate and predict flow characteristics in a certain physical space. Since the numerical result of CFD computation is very hard to understand, VR (virtual reality) and data visualization techniques are introduced into CFD post-processing to improve the understandability and functionality of CFD computation. In many cases CFD datasets are very large (multi-gigabytes), and … more
Date: August 5, 2003
Creator: Li, Song
Partner: UNT Libraries Government Documents Department
open access

Correlation Between Domain Behavior and Magnetic Properties of Materials

Description: Correlation between length scales in the field of magnetism has long been a topic of intensive study. The long-term desire is simple: to determine one theory that completely describes the magnetic behavior of matter from an individual atomic particle all the way up to large masses of material. One key piece to this puzzle is connecting the behavior of a material's domains on the nanometer scale with the magnetic properties of an entire large sample or device on the centimeter scale. In the firs… more
Date: May 31, 2003
Creator: Leib, Jeffrey Scott
Partner: UNT Libraries Government Documents Department
open access

Nuclear Spin Lattice Relaxation and Conductivity Studies of the Non-Arrhenius Conductivity Behavior in Lithium Fast Ion Conducting Sulfide Glasses

Description: As time progresses, the world is using up more of the planet's natural resources. Without technological advances, the day will eventually arrive when these natural resources will no longer be sufficient to supply all of the energy needs. As a result, society is seeing a push for the development of alternative fuel sources such as wind power, solar power, fuel cells, and etc. These pursuits are even occurring in the state of Iowa with increasing social pressure to incorporate larger percentages … more
Date: May 31, 2003
Creator: Meyer, Benjamin Michael
Partner: UNT Libraries Government Documents Department
open access

Process Optimization for Solid Extraction, Flavor Improvement and Fat Removal in the Production of Soymilk From Full Fat Soy Flakes

Description: Traditionally soymilk has been made with whole soybeans; however, there are other alternative raw ingredients for making soymilk, such as soy flour or full-fat soy flakes. US markets prefer soymilk with little or no beany flavor. modifying the process or using lipoxygenase-free soybeans can be used to achieve this. Unlike the dairy industry, fat reduction in soymilk has been done through formula modification instead of by conventional fat removal (skimming). This project reports the process opt… more
Date: May 31, 2003
Creator: Prawiradjaja, Stanley
Partner: UNT Libraries Government Documents Department
open access

Is Lutein a Physiologically Important Ligand for Transthyretin in Humans?

Description: Lutein and zeaxanthin are the only carotenoids accumulated in the macula of the human retina and are known as the macular pigments (MP). These pigments account for the yellow color of the macula and appear to play an important role in protecting against age-related macular degeneration (AMD). The uptake of lutein and zeaxanthin in human eyes is remarkably specific. It is likely that specific transport or binding proteins are involved. The objective is to determine whether transthyretin (TTR) is… more
Date: May 31, 2003
Creator: Chen, Liwei
Partner: UNT Libraries Government Documents Department
open access

Long-Term Cyclic Oxidation Behavior of Wrought Commercial Alloys at High Temperatures

Description: The oxidation resistance of a high-temperature alloy is dependent upon sustaining the formation of a protective scale, which is strongly related to the alloying composition and the oxidation condition. The protective oxide scale only provides a finite period of oxidation resistance owing to its eventual breakdown, which is especially accelerated under thermal cycling conditions. This current study focuses on the long-term cyclic oxidation behavior of a number of commercial wrought alloys. The a… more
Date: August 5, 2003
Creator: Li, Bingtao
Partner: UNT Libraries Government Documents Department
open access

Miniaturized Analytical Platforms From Nanoparticle Components: Studies in the Construction, Characterization, and High-Throughput Usage of These Novel Architectures

Description: The scientific community has recently experienced an overall effort to reduce the physical size of many experimental components to the nanometer size range. This size is unique as the characteristics of this regime involve aspects of pure physics, biology, and chemistry. One extensively studied example of a nanometer sized experimental component, which acts as a junction between these three principle scientific theologies, is deoxyribonucleic acid (DNA) or ribonucleic acid (RNA). These biopolym… more
Date: August 5, 2003
Creator: Pris, Andrew David
Partner: UNT Libraries Government Documents Department
open access

Electron-positron production in ultra-peripheral heavy-ion collisions with the STAR experiment

Description: This thesis presents a measurement of the cross-section of the purely electromagnetic production of e{sup +}e{sup -} pairs accompanied by mutual nuclear Coulomb excitation AuAu {yields} Au*Au* + e{sup +}e{sup -}, in ultra-peripheral gold-gold collisions at RHIC at the center-of-mass collision energy of {radical}S{sub NN} = 200 GeV per nucleon. These reactions were selected by detecting neutron emission by the excited gold ions in the Zero Degree Calorimeters. The charged tracks in the e{sup +}e… more
Date: August 1, 2003
Creator: Morozov, Vladimir Borisovitch
Partner: UNT Libraries Government Documents Department
open access

Process environmental philosophy

Description: A process-information approach is examined as a foundation for an environmental philosophy that is dynamic and elastic, with particular emphasis on value, beauty, integrity and stability supporting Aldo Leopold's vision. I challenge one of the basic assumptions of Western philosophy, namely the metaphysical primacy of substance. The classical, medieval and modern metaphysics of substance is presented with particular attention given the paradoxes of substance. Starting from the philosophy of Her… more
Date: May 2003
Creator: Corbeil, Marc J.V.
Partner: UNT Libraries
open access

An Investigation into the Effects of Long-term Staff Development on Teacher Perceptions and Reading Achievement on Young Children

Description: The effectiveness of long-term staff development (Reading Academy Project-RAP) on students' reading scores on the Texas Assessment of Academic Skills (TAAS) test was examined to determine if teachers transferred newly learned teaching strategies into practice and changed their beliefs about reading instruction. In a four-year cohort longitudinal study in an East Texas rural community, the effects of long-term staff development on third grade students' TAAS test reading scores, teacher practices… more
Date: May 2003
Creator: Boatman, Vikki
Partner: UNT Libraries
open access

Knowledge and attitudes of preservice teachers towards students who are gay, lesbian, bisexual, or transgendered.

Description: The study used a survey design to ascertain the levels of knowledge and attitudes of special education and non-special education preservice and inservice teachers towards students with different sexual orientations. The results of this study are based on 408 responses from preservice and inservice teachers enrolled at seven institutions of higher education within North Carolina, Virginia, and the District of Columbia offering teacher training programs in regular and/or special education. Two pr… more
Date: December 2003
Creator: Morgan, Daniel J.
Partner: UNT Libraries
open access

Developmental Patterns of Metabolism and Hematology in the Late Stage Chicken Embryo (Gallus Domesticus) at Two Incubation Temperatures.

Description: How temperature affects physiological development in the chicken embryo is unknown. Embryos incubated at 38°C or 35°C showed no difference in growth or survival. The time to hatching was longer in 35°C than 38°C embryos (23.7 vs. 20.6 days), but unaffected was the relative timing of appearance of developmental landmarks (internal, external pipping). At stage 43-44, 38°C embryos maintained oxygen consumption around 1 mL/g/h despite acute temperature reduction (suggesting thermoregulatory maturat… more
Date: May 2003
Creator: Black, Juli
Partner: UNT Libraries
open access

Cost Savings Realized Through Proper Sizing of an Excessive Instrument Air System.

Description: The purpose of this research was to determine if installing a smaller air compressor could reduce the electrical usage of a large semiconductor manufacturing plant. A 200 horsepower Atlas Copco compressor was installed with the existing 500 horsepower Ingersoll-Rand compressors. Testing was conducted during the regular manufacturing process at MEMC Southwest in Sherman, Texas. Analysis of the data found that installing the new compressor could reduce electrical consumption. The study also found… more
Date: December 2003
Creator: Condron, Ewell D.
Partner: UNT Libraries
open access

Texas Cities and the Economic Development Sales Tax

Description: Competition to lure corporations has become an enormous issue between states. Smaller communities feel unable to participate in economic development opportunities since their budgets do not provide the necessary funding. In 1979, the Texas state legislature passed the Development Corporation Act in an attempt to aid the smaller communities' quest for economic development. The Act allowed for the creation of local development corporations; however, it did not provide a sufficient funding source … more
Date: December 2003
Creator: Comer-HaGans, DeLawnia
Partner: UNT Libraries
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