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Graduate Theses, Dissertations, and Problem Reports (ETD)

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Improved Velocity Data In Circular Jets Using An Avalanche Photodiode-Based 2-Component Point Doppler Velocimeter, Thomas Trent Scarberry Dec 2001

Improved Velocity Data In Circular Jets Using An Avalanche Photodiode-Based 2-Component Point Doppler Velocimeter, Thomas Trent Scarberry

Graduate Theses, Dissertations, and Problem Reports (ETD)

An existing Point Doppler Velocimeter (pDv) has been modified in an effort to improve the RMS velocity results. Improvements have been made by reducing the probe volume size by focusing the incident laser beam, thereby reducing the effects of spatial averaging on the mean and RMS velocity measurements.;In particular, the PIN photodetectors used previously, were tested using the reduced probe volume, and were then replaced by high-gain, high signal-to-noise ratio large area avalanche photodetectors (APD's).;Comparisons have been made between the data acquired and hot wire data obtained on the same jet flow, as well as data obtained in previous pDv …

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Detection Of Subsurface Anomalies In Fiber-Reinforced Polymer (Frp) Wrapped Timber Bridge Components Using Infrared Thermography, William Edward Steele Iii Dec 2001

Detection Of Subsurface Anomalies In Fiber-Reinforced Polymer (Frp) Wrapped Timber Bridge Components Using Infrared Thermography, William Edward Steele Iii

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis presents the results of an experimental study on the use of Infrared Thermography technique for detection of subsurface anomalies in fiber reinforced polymer (FRP) wrapped timber bridge components. An extensive literature review on the application of various nondestructive evaluation techniques to composite structures has also been presented.;Simulated subsurface delaminations were constructed in the laboratory in timber piles wrapped with FRP composite fabric. The delaminations varied in size, thickness, and severity. These delaminations were placed between the 1/8&inches; thick FRP wrap and timber surface. The thermal images from the delaminated specimens were compared with thermal images from undamaged specimens …

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Study Of West Virginia Wood Industry Roundwood Consumption In 1999, O'Dell Emanuel Tucker Dec 2001

Study Of West Virginia Wood Industry Roundwood Consumption In 1999, O'Dell Emanuel Tucker

Graduate Theses, Dissertations, and Problem Reports (ETD)

Use of wood composite products has increased over the last decade in the market for construction material. Softwood species and soft hardwood species are the preferred forest resources for manufacturing these products. Reduction in available softwood forest resources from the Western states has forced a shift to use of more soft hardwood species in the Northeast. What impact this shift may have on the forest resources in the Northeast is not known.;The objective of this study was to canvass primary wood manufacturers in and around the forest of West Virginia and determine how roundwood consumption has changed since the shift …

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Parent-Infant Interactions During Acute Painful Procedures, Catherine Bradford Mcclellan Dec 2001

Parent-Infant Interactions During Acute Painful Procedures, Catherine Bradford Mcclellan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Despite the current recognition of infant procedural pain and distress, there is a dearth of research, both in the assessment and treatment literature, of infant procedural distress. This study examined how specific parent behaviors relate to infant procedural distress and whether this relation is mediated by birth order. Results indicated that females were rated as more distressed than were males, and that birth order did not prove to be a distinguishing factor in infant distress. Finally, while some behaviors appear to have a similar influence on both preschoolers' and infants' behaviors, parents' behavior during infants' distressing procedures were found to …

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Order Effects Of Fear And Pain Induction, Kevin Erik Vowles Dec 2001

Order Effects Of Fear And Pain Induction, Kevin Erik Vowles

Graduate Theses, Dissertations, and Problem Reports (ETD)

Although pain responding and emotional states such as fear are highly correlated and appear to interact, the causal relations between these variables have yet to be fully defined. This study sought to further illuminate these relations by investigating how exposure to one of these states (i.e., pain or fear) affects responding to the other. The order in which participants experienced fearful or painful stimuli was manipulated, as well as fear level (i.e., "low" & "high"). Measures of behavioral escape, heart rate, and verbal reports were obtained throughout four experimental trials, as well as rankings of aversiveness for all stimuli encountered. …

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Green Tea Antioxidants Inhibition Of Oxidation And Mutation, Paul Stout Mcconnell Aug 2001

Green Tea Antioxidants Inhibition Of Oxidation And Mutation, Paul Stout Mcconnell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Green tea is a complex mixture containing several major potent antioxidants e.g., flavins and/or polyphenols. These antioxidants in green tea may react directly or indirectly with strong oxidizers e.g. peroxynitrite or its constituents (superoxide or nitric oxide). Green tea antioxidants can destroy the oxidants. Based on a simple chemical interaction of peroxynitrite (OONO-) and luminol, blue light is produced upon oxidation. It was shown that green tea and constituents have light inhibitory capabilities. In order to show the possible beneficial effects of green tea with DNA, plasmids were chosen to determine whether or not green tea was also capable of …

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Simulation Based Modeling Of The Elastic Properties Of Structural Wood Based Composite Lumber, Laszlo Bejo Aug 2001

Simulation Based Modeling Of The Elastic Properties Of Structural Wood Based Composite Lumber, Laszlo Bejo

Graduate Theses, Dissertations, and Problem Reports (ETD)

The importance of wood-based composite lumber is increasing in the US market for construction materials. Manufacturers of such composites strive to make their products more competitive by increasing their value. This dissertation describes the development of simulation models that can aid these efforts by estimating the elastic characteristics of composite lumber products. The study included the assessment of the orthotropic mechanical properties of the raw material, the effect of densification it experiences during the hot-pressing procedure, and the geometric structure of the composites. Using the results of these investigations, computer models were created based on principles of deterministic and stochastic …

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Analytical And Experimental Study Of Frp Honeycomb Sandwich Panels With Sinusoidal Core, Justin Mark Robinson Aug 2001

Analytical And Experimental Study Of Frp Honeycomb Sandwich Panels With Sinusoidal Core, Justin Mark Robinson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Fiber reinforced plastic (FRP) composite materials and structures have been increasingly used in highway bridge applications. Recent applications have demonstrated that FRP honeycomb sandwich panels with sinusoidal core can be effectively and economically used for highway bridge deck systems. In this study, analytical and experimental characterizations are presented for a FRP honeycomb panel with sinusoidal core geometry in the plane and extending vertically between face laminates. To verify the accuracy of the a closed-form solution, several honeycomb sandwich beams with sinusoidal core waves either in the longitudinal or transverse directions are tested in bending and torsion. Also, a deck panel …

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Exploratory Study On High-Performance Concrete For Bridge Decks In West Virginia, Wenbo Zhang Aug 2001

Exploratory Study On High-Performance Concrete For Bridge Decks In West Virginia, Wenbo Zhang

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study is intended to provide guidelines for a future global effort on the development of HPC mixes in West Virginia using several types of available aggregates. The objective of the present study is to explore the performance of two types of mixtures using fly ash and slag, respectively, and the same limestone coarse aggregate, natural sand, and constant water/cementitious ratio. For each type, three mixtures were evaluated, with one of the three being defined according to the WVDOT-DOH specifications as a reference (20% fly ash and 30% slag by weight of total cementitious material), from which we varied the …

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Nondestructive Testing Of Reinforced And Prestressed Concrete Structures Using Acoustic Waveguides, Komwut Wissawapaisal Aug 2001

Nondestructive Testing Of Reinforced And Prestressed Concrete Structures Using Acoustic Waveguides, Komwut Wissawapaisal

Graduate Theses, Dissertations, and Problem Reports (ETD)

The main objective of this research is to develop both passive and active nondestructive testing techniques for reinforced and prestressed concrete structures using acoustic waveguides. The first technique introduces a two-dimensional surface waveguide to enlarge the acoustic emission (AE) monitoring area of a reinforced concrete structure. A two-dimensional steel wire system is developed as an acoustic waveguide to study the AE behavior of a reinforced concrete floor slab. AE sensors are mounted to the end of the waveguides to detect AE signals, which are generated by pencil-lead breaks at various locations on concrete surface. Results show that the use of …

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Effect Of Pretreatment On The Performance Of Metal Contaminated Commercial Fcc Catalyst, Oguz Bayraktar Aug 2001

Effect Of Pretreatment On The Performance Of Metal Contaminated Commercial Fcc Catalyst, Oguz Bayraktar

Graduate Theses, Dissertations, and Problem Reports (ETD)

The performance of fluid catalytic cracking (FCC) catalyst decreases due to the severe negative effects of metal contaminants (e.g., nickel, vanadium and iron) deposited on the catalyst from the hydrocarbon feed. The metal contaminants cause an increase in the production of gas and coke at the expense of gasoline.;In this work the effect of pretreatment with hydrogen and methane gases on the performance of commercial, metal-contaminated, FCC equilibrium catalysts was investigated. Cracking reactions of both sour imported heavy gas oil (SIHGO) and n-hexadecane were carried out in a microactivity test (MAT) unit using three commercial equilibrium catalysts with different metals …

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Numerical Model For Determining The Wetting Front In A Clay Layer Of A Leaking Composite Barrier, Mustafa Eftelioglu Aug 2001

Numerical Model For Determining The Wetting Front In A Clay Layer Of A Leaking Composite Barrier, Mustafa Eftelioglu

Graduate Theses, Dissertations, and Problem Reports (ETD)

Composite barriers for hazardous and solid waste landfills are designed to minimize hydraulic transport of the contaminant leachate of the landfill; however, the geomembrane can be damaged during construction or otherwise contain imperfections from manufacturing. It is desirable to estimate the discharge characteristics and the flow width of such a leachate should leaks in the geomembrane occur.;Numerical solutions of the flow equations for unsaturated soil barriers can provide an understanding of the movement of a leachate through a composite barrier. The purpose of this investigation was to develop a computer model that simulated two-dimensional migration of leachate beneath holes in …

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Damage Mechanics Of Human Cortical Bone, Gagik Parsam Parsamian Aug 2001

Damage Mechanics Of Human Cortical Bone, Gagik Parsam Parsamian

Graduate Theses, Dissertations, and Problem Reports (ETD)

Skeletal fragility is an important orthopedic concern including the prevention of osteoporosis, long-term stability of prosthetic implants and stress fractures. Damage in human cortical bone has been implicated as a cause of increased fragility and is thought to initiate bone remodeling. Therefore, characterization of the mechanisms of damage initiation and accumulation in bone is challenging not only from the engineering prospective but also has a potential of revealing new insights in its physiology. The main objectives of this dissertation work were to study the early stages of damage development in human cortical bone and develop a constitutive formulation describing damage …

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Design And Analysis Of A Hybrid Steel/Composite Pipe For High-Pressure Applications, William Jennings Briers Iii Aug 2001

Design And Analysis Of A Hybrid Steel/Composite Pipe For High-Pressure Applications, William Jennings Briers Iii

Graduate Theses, Dissertations, and Problem Reports (ETD)

Once limited almost exclusively to aerospace applications, the use of composite materials has become widespread among many high performance industries. Today's petroleum industry is requiring piping systems to sustain high pressures, impact, rugged handling, and harsh environmental conditions such as corrosion and temperature. Advances in the last decade of engineered materials have opened the way for more conversions from metal to composites.;The objective of this research is to develop a lightweight composite pipe that meets the performance requirements of an existing high-pressure steel pipe. This development is crucial to the petroleum industry where hydraulic-fracturing services are demanding lighter weight materials …

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Real World Heavy-Duty Vehicle Emissions Modeling, Paul Andrei Aug 2001

Real World Heavy-Duty Vehicle Emissions Modeling, Paul Andrei

Graduate Theses, Dissertations, and Problem Reports (ETD)

Heavy-duty vehicle emissions represent a significant portion of the mobile source emissions inventory. Accurate estimation of their contribution is essential as on-highway and non-road heavy-duty diesel emissions account for at least one third of the oxides of nitrogen (NOx) in the inventory. West Virginia University (WVU) has developed an extensive database of continuous transient gaseous emissions levels from a wide variety of heavy-duty vehicles in field operation. The database was built using WVU Transportable Heavy-Duty Vehicle Emissions Testing Laboratories (THDVETL). Several different transient cycles were utilized for testing including the Central Business District (CBD) schedule.;Several speed correction factors were developed …

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Green-Ampt Infiltration Model Parameter Determination Using Scs Curve Number (Cn) And Soil Texture Class, And Application To The Scs Runoff Model, Elena Viktorovna Brevnova Aug 2001

Green-Ampt Infiltration Model Parameter Determination Using Scs Curve Number (Cn) And Soil Texture Class, And Application To The Scs Runoff Model, Elena Viktorovna Brevnova

Graduate Theses, Dissertations, and Problem Reports (ETD)

The U.S. Department of Agriculture (USDA) Soil Conservation Service Curve Number (SCS CN) method is a simple and widely popular technique of estimation of direct runoff volume for design and natural rainfall events in small watersheds. The SCS CN procedure is incorporated into such computer programs as TR-20 and TR-55. Although the method reliably predicts 24-hr runoff volume, the predicted distribution of runoff during a storm event is not realistic. This shortcoming of the SCS CN method is due to weakness in the infiltration concept of the method. Use of a physically realistic and distributed Green-Ampt infiltration model can significantly …

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Hybrid Arq With Parallel And Serial Concatenated Convolutional Codes For Next Generation Wireless Communications, Naveen Chandran Aug 2001

Hybrid Arq With Parallel And Serial Concatenated Convolutional Codes For Next Generation Wireless Communications, Naveen Chandran

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research focuses on evaluating the currently used FEC encoding-decoding schemes and improving the performance of error control systems by incorporating these schemes in a hybrid FEC-ARQ environment. Beginning with an overview of wireless communications and the various ARQ protocols, the thesis provides an in-depth explanation of convolutional encoding and Viterbi decoding, turbo (PCCC) and serial concatenated convolutional (SCCC) encoding with their respective MAP decoding strategies.;A type-II hybrid ARQ scheme with SCCCs is proposed for the first time and is a major contribution of this thesis. A vast improvement is seen in the BER performance of the successive individual FEC …

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Development Of A Micro-Dilution Tunnel System For In-Use, On-Board Heavy-Duty Vehicle Particulate Matter Emissions Measurement, Emily Deanna Cirillo Aug 2001

Development Of A Micro-Dilution Tunnel System For In-Use, On-Board Heavy-Duty Vehicle Particulate Matter Emissions Measurement, Emily Deanna Cirillo

Graduate Theses, Dissertations, and Problem Reports (ETD)

A novel portable particulate matter measuring system was designed, developed and qualified. The heavy-duty engine Federal Test Procedure (FTP) requires the use of a full-flow tunnel to measure particulate emissions from diesel fueled engines. However, a full-flow tunnel based constant volume sampler (CVS) system is not only expensive to build and maintain, it also requires a large work space. The portable micro-dilution system that could be used for measuring on-board, in-use emissions from heavy-duty vehicles would cost significantly less. The micro-dilution tunnel operates on the same principle as a full-flow dilution tunnel. The added advantage of the proposed design is …

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Numerical Modeling Of Chemical Recovery From Black Liquor Char, Dharmarajan Hariharan Aug 2001

Numerical Modeling Of Chemical Recovery From Black Liquor Char, Dharmarajan Hariharan

Graduate Theses, Dissertations, and Problem Reports (ETD)

A complete CFD model for the char burning stage of chemical recovery from black liquor is presented. Chemical recovery from black liquor is characterized by the occurrence of multiple, simultaneous reactions occurring in dynamic flow conditions. Rate equations for the different chemical reactions are incorporated into a multiphase CFD code MFIX. Rate equations for sulfate reduction by carbon, gasification of carbon by CO2 and H2O, and, COS and H2S formation, are incorporated into MFIX, to simulate the chemical kinetics occurring in the char burning stage. Oxidation of carbon and Na 2S by O2 are also included.;Pyrolysis of black liquor char …

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Static And Dynamic Inventory Models Under Inflation, Time Value Of Money And Permissible Delay In Payment, Babak Khorrami Aug 2001

Static And Dynamic Inventory Models Under Inflation, Time Value Of Money And Permissible Delay In Payment, Babak Khorrami

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this research a number of mathematical models were developed for static and dynamic deterministic single-item inventory systems. Economic factors such as inflation, time value of money and permissible delay in payment were considered in developing the models. Nonlinear optimization techniques were used to obtain the optimal policies for the systems.;First, a static single-item inventory model was considered in which shortages are allowed and a delay is permitted in payment. In this case, suppliers allow the customers to settle their accounts after a fixed delay period during which no interest is charged.;An extension of the model was then considered in …

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Numerical Modeling Of Cold Flow And Hot Gas Desulfurization In A Circulating Fluidized Bed, Neeraj N. Pugalia Aug 2001

Numerical Modeling Of Cold Flow And Hot Gas Desulfurization In A Circulating Fluidized Bed, Neeraj N. Pugalia

Graduate Theses, Dissertations, and Problem Reports (ETD)

Section I. This work was carried out to understand the behavior of the solid and gas phases in a CFB riser. Only the riser is modeled as a straight pipe. A model with linear algebraic approximation to solids viscosity of the form, mus = 5.34epsilons, (epsilon s is the solids volume fraction) with an appropriate boundary condition at the wall obtained by approximate momentum balance solution at the wall to account for the solids recirculation is tested against experimental results. The work done was to predict the flow patterns in the CFB risers from available experimental data, including data from …

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Mobile Agent-Based Attack-Resistant Architecture For Distributed Intrusion Detection System, Sentil Kumar Selliah Aug 2001

Mobile Agent-Based Attack-Resistant Architecture For Distributed Intrusion Detection System, Sentil Kumar Selliah

Graduate Theses, Dissertations, and Problem Reports (ETD)

The majority of the Distributed Intrusion Detection systems lack measures for providing security and integrity to their own components. The hierarchical organization and the static nature of the intrusion detection components in a largely distributed environment make them the likely targets of attacks. By disabling few operationally critical components along the hierarchy, an attacker can succeed in disabling the system's capability to correctly detect intrusions. One solution to this problem is to eliminate the system components' static nature by wrapping them as mobile agents. Through mobility we achieve an attack resistant architecture for the hierarchical distributed intrusion detection components. As …

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Analysis Of Particulate Matter Concentration And Size Distribution In Heavy-Duty Vehicle Exhaust Emissions, Zhuyun Xu Aug 2001

Analysis Of Particulate Matter Concentration And Size Distribution In Heavy-Duty Vehicle Exhaust Emissions, Zhuyun Xu

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study put forward a method to predict the concentration field in the plume of a heavy-duty truck, operating at highway speed. It provided information regarding computation of dispersion coefficients in the area near a stack.;The numerical cumulative frequency fit method obtained in this study provided an effective and quick means for determining the particle size distribution parameters (the mass median aerodynamic diameters and geometric standard deviations) of sample data for the multi-modal distribution.;The particle size distribution of the compressed natural gas buses tested was characterized by a bi-modal particle size distribution; the clean diesel buses had a uni-modal particle …

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Seasonal Plasticity Of A15 Dopaminergic Neurons In The Ewe, Van Lee Adams Aug 2001

Seasonal Plasticity Of A15 Dopaminergic Neurons In The Ewe, Van Lee Adams

Graduate Theses, Dissertations, and Problem Reports (ETD)

In the ewe, anestrus is caused by increased sensitivity to E2 negative feedback that is mediated by A15 dopaminergic neurons that are only responsive to E2 in anestrus. Experiment 1, tested the hypothesis that synaptic input on A15 neurons varies with season by examining synapsin-positive close contacts on A15 cells using immunofluorescence and confocal microscopy. The number of contacts on dendrites, but not somata, increased during anestrus. There were also corresponding changes in dendritic morphology including an increase in dendritic length, surface area, and number of bifurcations. Because thyroid hormones are necessary for the transition to anestrus, we next examined …

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Factors Contributing To College Freshmen Placed On Academic Probation, Lee Ann Vecellio Aug 2001

Factors Contributing To College Freshmen Placed On Academic Probation, Lee Ann Vecellio

Graduate Theses, Dissertations, and Problem Reports (ETD)

The responses of college freshmen placed on academic probation to a survey examining the factors leading to their poor academic performance were studied to ascertain the perceived problem areas. One hundred and seventy-two college freshmen selected factors concerning motivation, time management, social, and financial components, which they believed contributed to their poor academic performance during their freshman year. For males, inadequate balance between time and other activities was perceived as the number one factor contributing to their demise. On the other hand, females selected lack of academic motivation as their number one factor. Interestingly, these factors were reversed when identifying …

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Genetic Evaluation Of Cytochrome P450 Expression In Smoking And Nonsmoking Women, Satya Vijayanand Vadlamuri May 2001

Genetic Evaluation Of Cytochrome P450 Expression In Smoking And Nonsmoking Women, Satya Vijayanand Vadlamuri

Graduate Theses, Dissertations, and Problem Reports (ETD)

1. Regiospecific expression of CYP1A1 and CYP1B1 in human uterus of nonsmokers. The goal of this study was to investigate the expression of these isoforms in different regions of the human uterus. Expression was determined in the endometrium, endocervix and squamous (exocervix) regions from six nonsmoking women by using RT-PCR. The transcripts encoding for CYP1A1 were significantly higher (p < 0.05) in the squamous (exocervix) region compared to other areas. However the expression of CYP1B1 was significantly higher (p < 0.05) in the endometrium. CYP1B1 expression appeared to be extremely low in a woman in the secretory stage of the menstrual phase, relative to the endometrium of the other patients who were all in the proliferative stage at hysterectomy. It appears that variability in the expression of these isoforms may be responsible for the differential susceptibility to cancer in women.;2. Influence of menstrual phase and smoking status on expression of CYP1A1 and CYP1B1 in different regions of the uterus. The goal of this study was to investigate the expression of these isoforms in different regions of the uterus from smokers and nonsmokers. These results indicate that CYP1A1 and CYP1B1 are expressed variably in different regions of the human uterus. The expression of CYP1B1 may be susceptible both to hormonal control and cigarette smoking. The variability in the expression of these isoforms may be responsible for the differential susceptibility to cancer in some women.;3. The effect of menstrual phase on CYP3A expression in human endometrium. The CYP3A family consists of four closely related proteins. Of these, CYP3A3/4 is the most abundant P450 isoform and is responsible for metabolizing estrogen as well as a variety of therapeutic agents, whereas CYP3A7, the fetal liver form, is involved in the biosynthesis of estriol. The goal of this study was to evaluate the expression of these two major CYP3A isoforms in human uterine tissue during the proliferative (PROL) and secretory (SEC) phases of the menstrual cycle. Expression of CYP3A7 in endometrium appeared to be several fold higher (∼10-fold) in the proliferative phase compared to the secretory phase. CYP3A4 expression was comparable between the two phases of the menstrual cycle. The RTPCR results indicated differential expression of CYP3A7 in various phases of the menstrual cycle. These results indicate that CYP3A isoforms may be subject to hormonal regulation during the menstrual cycle in endometrium of premenopausal women. (Abstract shortened by UMI.).

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Perceptions Of Benefits/Problems Of Part-Time Employment On The Job Performance Of Secondary Teachers Of Agricultural Education, Connie Mcclung Scarbrough May 2001

Perceptions Of Benefits/Problems Of Part-Time Employment On The Job Performance Of Secondary Teachers Of Agricultural Education, Connie Mcclung Scarbrough

Graduate Theses, Dissertations, and Problem Reports (ETD)

The purpose of the study was to examine the self-perceived potential benefits and/or problems of part-time employment on the job performance of secondary teachers of Agricultural Education. The population consisted of 108 agricultural educators who held teaching positions during the 2000--2001 school year in West Virginia, Ohio, and Kentucky and were employed within a 150-mile radius of Ripley, West Virginia. A descriptive research design was used for the study. There have been no studies conducted as to the number of agricultural educators involved in part-time employment and to what extent they are involved. Many have questioned the feasibility of a …

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Using Virtual Reality For Requirements Validation, Dejan Desovski May 2001

Using Virtual Reality For Requirements Validation, Dejan Desovski

Graduate Theses, Dissertations, and Problem Reports (ETD)

Failures of high consequence systems are intolerable. Studies have shown that a significant percentage of safety problems can be traced back to errors in the specification. An important problem that arises during validation is how to include a domain expert in this process. Although the domain experts have exclusive knowledge about the system operation, they may not understand formalisms used for system specification.;Essential type of "evidence" of the correctness of the formalization process must be provided by human-based calculation. Human calculation can be significantly amplified by shifting from symbolic representation to graphical representations. This, in turn, provides an environment for …

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Pattern Recognition In Software Engineering Trend Adapting, Dapeng Chen May 2001

Pattern Recognition In Software Engineering Trend Adapting, Dapeng Chen

Graduate Theses, Dissertations, and Problem Reports (ETD)

Whether and when to adapt to certain software engineering trends are difficult questions to be answered by many decision-makers. The main reasons are due to the fact that evolution of software engineering trends itself is determined by various factors, many of which come from the fields outside of the software technology, thus hard to predict. So it is even harder to estimate the cost and benefit when adapting to certain trends. This paper is intended to study ways to decrease the risk involved in such decision making processes, by developing a pattern from past software engineering trends. While the pattern …

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Field Observations Of The Early-Age Behavior Of Jointed Plain Concrete Pavements, Troy Haden Schell May 2001

Field Observations Of The Early-Age Behavior Of Jointed Plain Concrete Pavements, Troy Haden Schell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Newly constructed rigid PCC highway pavements with open graded stabilized base courses have been found to develop non-uniform, transverse saw-cut joint-crack developments and extensive slab movement behaviors, which cause unwanted premature joint failures. Phase I of this study determined the variables associated with the sporadic, large joint opening development by literature review, laboratory tests and some field collected data. The large joints were believed to develop at early-ages of the slabs curing (within the first 48 hours). The early-age stress developments were found controlled by slab temperature history, material property development and frictional resistance. Minimal recommendations for corrects to the …

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