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Graduate Theses, Dissertations, and Problem Reports (ETD)

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Creating Virginia: The Role Of John Lederer In The Transition Of Western Virginia From A Wilderness Into A Colony, Richard Jason Burns May 2006

Creating Virginia: The Role Of John Lederer In The Transition Of Western Virginia From A Wilderness Into A Colony, Richard Jason Burns

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis seeks to explore and explain the role of John Lederer, a German physician and expedition leader, in the creation of the colony of Virginia. Lederer led three expeditions into the western mountains of Virginia in the years 1670-71, and was the first European to document his expeditions in writing. Sir William Berkeley, Governor of Virginia, commissioned him to explore the western frontier of Virginia in hopes of finding a short route to the East India Sea. The immense commodities, trade, and settlement possibilities within the western Virginia region eventually overshadowed this initial goal.;Following the three expeditions, Lederer's expedition …

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Thermal Conductivity Characterization Of Composite Materials, Bhyrav Mutnuri May 2006

Thermal Conductivity Characterization Of Composite Materials, Bhyrav Mutnuri

Graduate Theses, Dissertations, and Problem Reports (ETD)

Thermal conductivity of a polymer composite is a function of resin type, fiber type and architecture, fiber volume fraction, direction of heat flow, and service temperature. Recognizing the thermal responses in Fiber Reinforced Polymer (FRP) composite decks play a critical role in their performance, accurate thermal measurements of FRP decks are essential.;The objective of the research is to attain better understanding of global and local thermal behavior of a composite structural system through fundamental understanding of thermal conductivity properties. The literature reveals that a major focus has been placed on measurements of thermal conductivity in through-the-thickness direction of a FRP …

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Livestock And Dairy Producers' Knowledge Of Quality Assurance Issues, Andrea L. Flanagan May 2006

Livestock And Dairy Producers' Knowledge Of Quality Assurance Issues, Andrea L. Flanagan

Graduate Theses, Dissertations, and Problem Reports (ETD)

The purpose of this study was to determine the level of knowledge and use of quality assurance practices by dairy and beef producers in West Virginia and to determine if differences in the level of use existed between D/BQA certified producers and non-certified producers. The population consisted of 125 West Virginia dairy producers identified on a Health Department list of regulated dairy farms within the state and 2,720 West Virginia beef producers from a database comprised of WV BQA certified producers and the South Branch and Buckhannon Stockyards mailing lists. A random sample of 92 dairy producers and 340 beef …

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Oxidative Stress In Skin Induced By Chemical And Physical Agents, Ashley Rebecca Murray May 2006

Oxidative Stress In Skin Induced By Chemical And Physical Agents, Ashley Rebecca Murray

Graduate Theses, Dissertations, and Problem Reports (ETD)

Free radicals threaten various tissues and are involved in the development and progression of many pathological states and diseases. More than other tissues, the skin is exposed to a variety of chemical, environmental, and physical agents which are capable of inducing radical formation resulting in the development of oxidative stress. The skin possesses an elaborate antioxidant network to deal with reactive oxygen species (ROS); however, excessive exposure and/or radical production can overwhelm the antioxidant capabilities of the skin causing oxidative damage to proteins, DNA, and lipids. The central hypothesis of these studies is that exposure to oxidizible chemicals and/or environmental …

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Intestinal And Systemic Cytotoxic T Lymphocyte And Humoral Immune Responses To Oral And Parenteral Reovirus Infection, Jonathan Reid Fulton May 2006

Intestinal And Systemic Cytotoxic T Lymphocyte And Humoral Immune Responses To Oral And Parenteral Reovirus Infection, Jonathan Reid Fulton

Graduate Theses, Dissertations, and Problem Reports (ETD)

This work was undertaken to determine effects of routes of infection with reovirus induction of responder cytotoxic T lymphocytes (CTL). Further, this work concerns differential effects of age on humoral and CTL responses following oral and parenteral reovirus infection. Despite considerable knowledge about non-intestinal systemic viral immunity, intestinal immune response to viral infection is less understood, and it remains unknown what differences, may occur in CTL populations induced by local viral infections in the intestine or systemic periphery.;We infected mice orally or in hind footpads with reovirus, serotype 1, strain Lang (TIL), and utilized flow cytometry to assess T cell …

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Effects Of Environmental Factors On The Paternal Brood Pouch And Sound Production In Two Sympatric Pipefish Species From The Chincoteague Bay, Virginia, Jennifer L. Ripley May 2006

Effects Of Environmental Factors On The Paternal Brood Pouch And Sound Production In Two Sympatric Pipefish Species From The Chincoteague Bay, Virginia, Jennifer L. Ripley

Graduate Theses, Dissertations, and Problem Reports (ETD)

Pipefishes and seahorses of the family Syngnathidae are important inhabitants of diminishing grass beds threatened by excessive nutrient loads, sedimentation, and chemical contaminants. This research examined the influence of these environmental factors on two sympatric pipefishes from the Chincoteague Bay, Virginia. Syngnathids are characterized by a unique mode of reproduction in which the male carries developing embryos in a placenta-like ventral brood pouch until the fry are free-swimming. Interspecific comparisons revealed differences in parental nutrient allocation to embryos. In Syngnathus fuscus, females produce nutritionally poor eggs and males implant developing embryos adjacent to blood vessels. The loose connection between eggs …

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Predictive Factors Of Brachial Plexus Neuropathy In Wrestling Athletes: A Prospective Longitudinal Study, Deena M. Dillard May 2006

Predictive Factors Of Brachial Plexus Neuropathy In Wrestling Athletes: A Prospective Longitudinal Study, Deena M. Dillard

Graduate Theses, Dissertations, and Problem Reports (ETD)

Context. Brachial plexus neuropathies are prevalent within wrestling. Objective. The purpose was to examine possible predisposing factors to brachial plexus neuropathy. Design. This study was a prospective longitudinal study. Setting. An athletic training room at an Eastern Wrestling League University (EWL). Patients and other participants. Twenty-three collegiate wrestlers ranging in age from 19.83 +/- 1.62 years volunteered to participate. Interventions. Neck strength, Head-neck segment, Head-neck length, and neck girth were measured. Previous history and number of years of wrestling were measured using a questionnaire. Main outcome measures. Neck strength and previous history may predispose wrestlers to brachial plexus neuropathy. Results. …

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Teaching Leadership Development At The Secondary Level: A National Study, Nathan Taylor May 2006

Teaching Leadership Development At The Secondary Level: A National Study, Nathan Taylor

Graduate Theses, Dissertations, and Problem Reports (ETD)

The purpose of this study was to determine the importance of different leadership skills taught to agriculture students and FFA members at the chapter level, where students and members receive leadership training, the frequency of training, and identify the instructors that provide leadership training. This study was a descriptive survey research conducted with agricultural science instructors who serve as FFA advisors of chapters recognized in the National Chapter Awards Program at the 78th National FFA Convention. The 10 most important skills identified by agriculture science teachers were (in order of importance); teamwork, opportunities in FFA, being responsible, setting personal or …

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A Comprehensive Analysis Of The Determinants Of State Medicaid Prescription Drug Expenditures, Sanjoy Roy May 2006

A Comprehensive Analysis Of The Determinants Of State Medicaid Prescription Drug Expenditures, Sanjoy Roy

Graduate Theses, Dissertations, and Problem Reports (ETD)

Prescription drug payments are the fastest growing and most widely varying expenditures across state Medicaid programs. To aid health policy efforts, this study identified determinants of drug utilization and expenditures using Andersen's Behavior Model of Health Services Utilization. A Structure Equation Model was built using five-year data for 48 states, to test relationships among the latent constructs of policy, access, predisposing characteristics, enabling resources, and need for healthcare; and, their influence on drug utilization. Only predisposing characteristics and enabling resources showed significant effects on drug utilization. Cluster Analysis classified state Medicaid programs into eight groups that differ on federal matching, …

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Decision -Making In The Use Of Instructional Technology By Novice And Experienced Public School Teachers, Amy L. Kuhn May 2006

Decision -Making In The Use Of Instructional Technology By Novice And Experienced Public School Teachers, Amy L. Kuhn

Graduate Theses, Dissertations, and Problem Reports (ETD)

The body of research on instructional technology (IT) reveals "what" influences teachers to use technologies and "which" technologies they use. Investigations into IT have not explored "how" and "why" teachers make decisions about teaching with technology. This study was not designed as yet another investigation into instructional technologies teachers use or to persuade teachers to use technology, but focused on teachers' decision-making to promote students' learning and the role of instructional technologies in this educational process.;Three novice (each with two years of teaching experience) and three experienced teachers (with an average of 26 years teaching experience) participated in this study. …

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Sensitivity Comparison Evaluation Of Computer-Generated Three Dimensional Surface Topography To Conventional Maxillofacial Radiographic Imagery, Michael A. Hazey Iii May 2006

Sensitivity Comparison Evaluation Of Computer-Generated Three Dimensional Surface Topography To Conventional Maxillofacial Radiographic Imagery, Michael A. Hazey Iii

Graduate Theses, Dissertations, and Problem Reports (ETD)

Objectives. LumenIQ's ImageIQ software enhances conventional radiographs by adding 3-D depth. This study evaluated whether a preference exists for ImageIQ format versus conventional radiographs, determined whether ImageIQ format is as sensitive as 2-D radiographs when detecting existing periodontal defects and simulated periodontal defects. Methods. 34 dental practitioners compared 12 radiographic cases with ImagelQ format. A panel of evaluators classified periodontal defects from 2-D radiographs and ImageIQ images. Simulated periodontal defects were radiographed with various radiographic variables altered, converted to ImageIQ 3-D format, and measured to evaluate the ImageIQ format compared to the 2-D control. Results . ImageIQ format showed improved …

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Spatial Variation In Brook Trout (Salvelinus Fontinalis ) Population Dynamics And Juvenile Recruitment Potential In An Appalachian Watershed, Zachary W. Liller May 2006

Spatial Variation In Brook Trout (Salvelinus Fontinalis ) Population Dynamics And Juvenile Recruitment Potential In An Appalachian Watershed, Zachary W. Liller

Graduate Theses, Dissertations, and Problem Reports (ETD)

I examined the spatial variation in brook trout population dynamics and juvenile recruitment potential in the upper Shavers Fork watershed, West Virginia. The objectives of my research were to (1) identify physico-chemical factors contributing to the spatial variation in the abundance of juvenile brook trout within small basin area stream reaches, (2) quantify patterns of brook trout distribution, movement, and post reproductive demographic parameters across multiple spatial scales, and (3) place the upper Shavers Fork watershed brook trout population along the continuum of watershed-scale metapopulation models. I sampled brook trout population size structure, physical habitat, and water chemistry at the …

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Chemotherapy Disrupts Bone Marrow Stromal Cell Function, Suzanne Davis Clutter May 2006

Chemotherapy Disrupts Bone Marrow Stromal Cell Function, Suzanne Davis Clutter

Graduate Theses, Dissertations, and Problem Reports (ETD)

A variety of bone marrow microenvironment derived signals influence steady state hematopoiesis as well as hematopoietic recovery following bone marrow transplantation. Bone marrow stromal cells found in this unique anatomical niche influence hematopoiesis, in pail, through production of soluble cytokines and chemokines. Developmental signals are also initiated by physical interaction of hematopoietic progenitor cells with stromal cells which are mediated by binding of their integrins to receptors on the stromal cell surface. Finally, the extracellular matrix, including many components produced by stromal cells, provides structure as well as a scaffold on which hematopoietic growth factors can be concentrated and stabilized …

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The Comparative Effects Of A Six-Week Balance Training Program, Gluteus Medius Strength Training Program, And Combined Balance Training/Gluteus Medius Strength Training Program On Dynamic Postural Control, Vincent J. Leavey May 2006

The Comparative Effects Of A Six-Week Balance Training Program, Gluteus Medius Strength Training Program, And Combined Balance Training/Gluteus Medius Strength Training Program On Dynamic Postural Control, Vincent J. Leavey

Graduate Theses, Dissertations, and Problem Reports (ETD)

Little is known about proprioception, gluteus medius strength, or combination training programs for improving dynamic balance. The purpose of this study was to assess the outcome of six weeks of gluteus medius strength training, proprioception training, and a combination of the two on dynamic balance. The study was a 2x4x8 and a 2x4 factorial design with three experimental groups and a control group. This study included 48 healthy, physically active, college-aged subjects. The six-week protocol for the experimental groups was conducted following a specific program three times a week for an average of 30-minutes. The proprioception training program included a …

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A Spatial Simultaneous Growth Equilibrium Modeling Of Agricultural Land Development In The Northeast United States, Yohannes G. Hailu May 2006

A Spatial Simultaneous Growth Equilibrium Modeling Of Agricultural Land Development In The Northeast United States, Yohannes G. Hailu

Graduate Theses, Dissertations, and Problem Reports (ETD)

With population growth and expansion of economic activities, urbanized places have expanded; and with growing per capita income, residential location preferences have shifted towards suburban and rural locations. In many places, such new growth has been accommodated with the development of agricultural lands. The concern from natural resource economics perspective is that agricultural lands are multifunctional. They have production uses, for which there are efficient markets, and amenity and environmental benefits, for which there are no efficient markets to value these attributes. This multifunctionality and the possible under-valuation of agricultural lands, irreversibility of development, and speculative effects of development on …

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Analysis Of Hybrid-Arq Based Relaying Protocols Under Modulation Constraints, Tarik K. Ghanim May 2006

Analysis Of Hybrid-Arq Based Relaying Protocols Under Modulation Constraints, Tarik K. Ghanim

Graduate Theses, Dissertations, and Problem Reports (ETD)

In a seminal paper published in 2001, Caire and Tuninetti derived an information theoretic bound on the throughput of hybrid-ARQ in the presence of block fading. However, the results placed no constraints on the modulation used, and therefore the input to the channel was Gaussian. The purpose of this thesis is to investigate the impact of modulation constraints on the throughput of hybrid-ARQ in a block fading environment. First, we consider the impact of modulation constraints on information outage probability for a block fading channel with a fixed length codeword. Then, we consider the effect of modulation constraints upon the …

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Projection Of Truck Traffic Volumes At Interstate Permanent Automatic Traffic Recorders, Alex M. Sanchez May 2006

Projection Of Truck Traffic Volumes At Interstate Permanent Automatic Traffic Recorders, Alex M. Sanchez

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study documents the development of a methodology and models to forecast truck traffic volumes on Interstate Highways at a selection of Permanent Automatic Traffic Recorder (PATR) sites. The models were developed using data collected over a period nine years (1995 to 2003) from sixteen permanent count stations located throughout the state. Eight sites were ultimately utilized, five along rural interstate highways and the others from urban interstate highways. Model development was based on the time series method, using two techniques: regression analysis and the growth factor technique. Both were analyzed and compared in order to select the most reliable …

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Perceptions Of Faculty And Students Toward The Obstacles Of Implementing E -Government In Educational Institutions In Saudi Arabia, Salah J. M. Alharbi May 2006

Perceptions Of Faculty And Students Toward The Obstacles Of Implementing E -Government In Educational Institutions In Saudi Arabia, Salah J. M. Alharbi

Graduate Theses, Dissertations, and Problem Reports (ETD)

The purpose of this study was to examine the perceptions of faculty members and students towards the obstacles of e-government implementation in educational institutions in Saudi Arabia. To collect data, the researcher developed two surveys and employed a quantitative research technique. The research population involved 101 faculty members and 305 students from the IPA, KSU and IMBSIU. Descriptive statistics, frequency and percentage were conducted for each variable. Means and standard deviations for all Likert-type scale variables were calculated. Testing for the equality of groups' means was conducted using t-test or Analyses of Variance (ANOVA). The level of significance was 0.05 …

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Detection And Analysis Of Deck Cracks In A Long Span Empirically Designed Bridge Deck Through Embedded Sensory Systems, Mourad Y. Riad May 2006

Detection And Analysis Of Deck Cracks In A Long Span Empirically Designed Bridge Deck Through Embedded Sensory Systems, Mourad Y. Riad

Graduate Theses, Dissertations, and Problem Reports (ETD)

Bridge decks exhibit premature longitudinal and transverse cracks leading to dramatic decrease in their service lives. Because of safety concerns, state highway agencies are overburdened by conducting annual visual inspections to detect signs of distresses in bridge elements and to provide continuous records of the conditions of such bridges. Those inspections are time consuming, and have multiple limitations which often yield controversial outputs. In this study, an instrumentation based system is designed and implemented on the Star City Bridge near Morgantown WV, to provide more sophisticated, and accurate methods to assess the structural performance of bridge elements, and hence provide …

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Object-Oriented Shipboard Electric Power System Library, Ram Praveen Saladi May 2006

Object-Oriented Shipboard Electric Power System Library, Ram Praveen Saladi

Graduate Theses, Dissertations, and Problem Reports (ETD)

The objective of this thesis is to explore the powerful capabilities of using an object-oriented modeling language to model and simulate an all electric Naval Shipboard Power System. Modelica has been used to model and simulate the shipboard power system which acts as an alternative simulation tool. The shipboard system is developed using the concept of packages. Different components like the buck converter, inverter, and AC machines have been modeled as a part of the library to develop the power system. The shipboard system has been simulated as two decoupled systems, the AC and DC systems. This research further focuses …

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The Development Of A Typology For Interracial Relationships, Juan M. D'Brot May 2006

The Development Of A Typology For Interracial Relationships, Juan M. D'Brot

Graduate Theses, Dissertations, and Problem Reports (ETD)

The purpose of this study was to determine whether Foeman and Nance's (1999) model of interracial relationship development could be adapted into a generalizable interracial relationship typology and whether there would be distinct differences in the affective, cognitive, and behavioral dimensions of each stage. Long-table analysis of four focus group interviews confirmed differences among the four stages of Foeman and Nance's model. Further examination of focus group transcripts revealed differences between the affective, cognitive, and behavioral dimension of each stage, but few differences between the affective and cognitive dimensions across stages. Implications for the study of relationship development, limitations, and …

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A Translator For Automated Code Generation For Service-Based Systems, Sanjib (Sean) Banerjee Jan 2006

A Translator For Automated Code Generation For Service-Based Systems, Sanjib (Sean) Banerjee

Graduate Theses, Dissertations, and Problem Reports (ETD)

Service based systems are playing a major role in industry today, everything from the verification of credit cards to booking airplane reservations are using some form of a service based approach. This unfortunately brings up a really big problem, how do we know that these services are actually doing what they are supposed to? Or, how do we know the service based system doesn't get somehow compromised when handling sensitive information.;A collaborative project involving Arizona State University and West Virginia University began in 2004 to first create a language, called alpha-calculus. We can prove that the code written in alpha-calculus …

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Shape Based Automated Mapping Of Histological Mouse Brain Sections, Manasa Danda Jan 2006

Shape Based Automated Mapping Of Histological Mouse Brain Sections, Manasa Danda

Graduate Theses, Dissertations, and Problem Reports (ETD)

In the development of an automatic image mapping system for mouse brain images, we focus on obtaining the best match in the two dimensional atlas images for the query image of a mouse brain section. The matching issue has to deal with the tissue distortions and tears, which are routinely encountered and possible scale, rotation and shear changes. With the goal to achieve high performance for image matching, a dual-stage approach is proposed which is based on radial distributions and region-based template matching.;Our main challenge is identifying shape features and corresponding distance metrics that produce effective characterization of 2D sections …

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Minimizing The Makespan In A Flexible Flowshop With Sequence Dependent Setup Times, Uniform Machines, And Limited Buffers, Bret Crowder Jan 2006

Minimizing The Makespan In A Flexible Flowshop With Sequence Dependent Setup Times, Uniform Machines, And Limited Buffers, Bret Crowder

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research addresses the problem of minimizing the makespan in a flexible flowshop with sequence dependent setup times, uniform machines, and limited buffers. A mathematical model was developed to solve this problem. The problem is NP-Hard in the strong sense and only very small problems could be solved optimally. For exact methods, the computation times are long and not practical even when the problems are relatively small. Two construction heuristics were developed that could find solutions quickly. Also a simulated annealing heuristic was constructed that improved the solutions obtained from the construction heuristics. The combined heuristics could compute a good …

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Three Essays On Political Regimes, Military Spending, And Economic *Growth, Pavel A. Yakovlev Jan 2006

Three Essays On Political Regimes, Military Spending, And Economic *Growth, Pavel A. Yakovlev

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation is a collection of essays on the issues in political and defense economics. Chapter 1 gives a brief introduction to the role that political and institutional arrangements play in affecting government policy and economic well-being. The second chapter examines how different political regimes and military manpower systems affect the value of life in military conflicts. The results in Chapter 2 show that democracies suffer lower battlefield casualties than dictatorships. Also noteworthy is that more volunteer based armies, per capita income, and economic freedom lead to lower battlefield deaths. Thus, political and economic liberties are found to increase the …

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Thermal Stress In Concrete Slabs Under Different Constraints, Dhananjay Rao Hejamadi Jan 2006

Thermal Stress In Concrete Slabs Under Different Constraints, Dhananjay Rao Hejamadi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Previous research has shown that thermal stresses developed in concrete pavements due to daily and seasonal temperature variations may be larger than those induced due to traffic loading. Dowel bars that are used for load transfer at the transverse joints of concrete pavements introduce high stresses at their interfaces with concrete leading to various forms of transverse joint distress. To solve this problem, Shoukry et al. (2001) developed an alternative design of dowel bars called "Shok Bar" that was installed by Shoukry and his team in a concrete pavement section placed at the parking lot of WVDOT Maintenance Shop at …

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Experimental And Numerical Investigation Of Seepage Into Longitudinal Drains, Ricardo Constantino Kiriakidis Longhi Jan 2006

Experimental And Numerical Investigation Of Seepage Into Longitudinal Drains, Ricardo Constantino Kiriakidis Longhi

Graduate Theses, Dissertations, and Problem Reports (ETD)

The effectiveness of longitudinal drains was investigated by using experimental and numerical methods. The main objective of the longitudinal drains was to extract and deflect the water flowing through the soil. The influence of water level, drain spacing, slope inclination and soil type was investigated. Results show that the longitudinal drains can reduce the amount of water flowing through the soil significantly.;Several soil types were used in order to cover a wide range of properties. Different soil types were obtained by mixing Ohio River sand and Kaolinite clay in different proportions depending on the desired hydraulic conductivity. In this research …

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Signaling Pathways Involved In Regulation Of Glucose -6 -Phosphate Dehydrogenase (G6pd) By Arachidonic Acid, Indrani Talukdar Jan 2006

Signaling Pathways Involved In Regulation Of Glucose -6 -Phosphate Dehydrogenase (G6pd) By Arachidonic Acid, Indrani Talukdar

Graduate Theses, Dissertations, and Problem Reports (ETD)

Glucose-6-phosphate dehydrogenase (G6PD) is the rate-limiting enzyme of pentose phosphate pathway and provides NADPH for de novo fatty acid biosynthesis. For the later reason, G6PD is known as a lipogenic enzyme. Insulin induces expression of G6PD mRNA via activating the PI3 kinase pathway in primary rat hepatocytes. Addition of arachidonic acid, a polyunsaturated fatty acid, in the medium interferes with the PI3 kinase pathway, and thus inhibits the insulin-mediated induction of G6PD. Arachidonic acid in the presence of insulin induces p38 MAP kinase pathway over insulin treatment alone. Activation of p38 MAP kinase by arachidonic acid interferes with the insulin …

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Transition-Metal Ions In Ii-Vi Semiconductors: Zinc Selenide And Zinc Telluride., Ming Luo Jan 2006

Transition-Metal Ions In Ii-Vi Semiconductors: Zinc Selenide And Zinc Telluride., Ming Luo

Graduate Theses, Dissertations, and Problem Reports (ETD)

II-VI semiconductors doped with transitional-metal (TM) ions have received much research interest for applications such as broadly tunable mid-infrared lasers and saturable absorber for 1.5 μm eyesafe lasers. In this work, several characterization techniques including absorption, photoluminescence (PL), time-resolved photoluminescence (TRPL) and electron paramagnetic resonance (EPR) were applied to study some TM-ion-doped samples. These samples include a set of Cr-doped ZnTe epilayers prepared by the molecular-beam epitaxy technique (MBE) and seven bulk polycrystalline ZnSe samples doped with Fe and/or Co. The PL study in the visible region applied on the set of Cr-doped ZnTe film samples revealed the possible contaminants …

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Epr And Endor Studies Of Point Defects In The Nonlinear Optical Crystals Rubidium Titanium Oxide Phosphate And Potassium Titanium Oxide Arsenate., Yongquan Jiang Jan 2006

Epr And Endor Studies Of Point Defects In The Nonlinear Optical Crystals Rubidium Titanium Oxide Phosphate And Potassium Titanium Oxide Arsenate., Yongquan Jiang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Four studies of point defects RbTiOPO4 and KTiOAsO4 crystals are described in this dissertation. In the first study, electron paramagnetic resonance (EPR) and electronnuclear double resonance (ENDOR) are used to characterize the complex hyperfine patterns exhibited by the primary radiation-induced trapped hole center in single crystals of RbTiOPO4 (commonly referred to as RTP). These defects are produced at 77 K by irradiating with x rays, and they are destroyed by raising the temperature above approximately 170 K. In this center, the hole resides on a bridging oxygen ion located between two titanium ions and is stabilized by a nearby rubidium …

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