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Graduate Theses, Dissertations, and Problem Reports (ETD)

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Raptor Abundance And Diversity And Red-Shouldered Hawk ( Buteo Lineatus) Habitat Characteristics On Reclaimed Mountaintop Mines In Southern West Virginia, Melissa J. Balcerzak Dec 2001

Raptor Abundance And Diversity And Red-Shouldered Hawk ( Buteo Lineatus) Habitat Characteristics On Reclaimed Mountaintop Mines In Southern West Virginia, Melissa J. Balcerzak

Graduate Theses, Dissertations, and Problem Reports (ETD)

Raptor abundance and diversity were compared between 4 treatments (grassland, shrub/pole, fragmented forest, and intact forest) over 3 seasons (migration, summer, and winter) on 3 mountaintop/valley fill mines in southern West Virginia. Habitat characteristics of Red-shouldered Hawks (Buteo lineatus) were examined at landscape and microhabitat scales. Forty-eight points were surveyed monthly (Feb. 2000--Jan. 2001) using broadcast calls. I quantified microhabitat characteristics within an 11.3 m radius plot and landscape characteristics within 1000 and 564 m buffer zones at each point. Abundance was highest in grasslands; richness did not differ among treatments. Overall, I detected a shift from a forest to …

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Robust Decentralized Control Of Power Systems Through Excitation Systems And Thyristor Controlled Series Capacitors, Lingling Fan Dec 2001

Robust Decentralized Control Of Power Systems Through Excitation Systems And Thyristor Controlled Series Capacitors, Lingling Fan

Graduate Theses, Dissertations, and Problem Reports (ETD)

The objective of this work is robust decentralized control of power systems through excitation systems and Thyristor Controlled Series Capacitors (TCSC). Hence the dissertation consists of two parts. In the first part an algorithm for the design of nonlinear decentralized excitation control is developed based on a feedback linearization technique. Feedback linearization technique is applied in excitation control of each generator to obtain an interconnected system where subsystems have linear system matrices and interconnections are represented by nonlinear terms. Different ways of achieving decentralization are investigated: (1) linear robust control combined with observer decoupled state space; (2) disturbance accommodation control. …

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Spatial And Temporal Analysis Of Radial Growth In An Appalachian Watershed, Desta Beyene Fekedulegn Dec 2001

Spatial And Temporal Analysis Of Radial Growth In An Appalachian Watershed, Desta Beyene Fekedulegn

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dendrochronological study used dated and measured tree-ring data to examine relationships between radial growth and climate for four hard wood species, yellow-poplar, northern red oak, chestnut oak and red maple, growing on contrasting topographic aspects of a watershed in north-central West Virginia.;The study showed that all species except northern red oak showed significant differences in growth between the mesic and xeric aspects. Where significant differences were found all except chestnut oak exhibited higher growth rates at the mesic aspect.;Yellow-poplar showed a sharp decline in growth from late 1950's to late 1960's, which was evidently caused by several years of …

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Prenatal Stress Alters Fear-Conditioned Behaviors And The Response To Serotonergic Drugs, William C. Griffin Iii Dec 2001

Prenatal Stress Alters Fear-Conditioned Behaviors And The Response To Serotonergic Drugs, William C. Griffin Iii

Graduate Theses, Dissertations, and Problem Reports (ETD)

Chronic, inescapable stress during pregnancy (i.e. prenatal stress) modifies the behavior of the adult offspring. Several behaviors were evaluated in adult prenatally stressed (PS) rats, most notably the acoustic startle response and behavioral inhibition (i.e. freezing). PS rats do not differ in baseline peak startle responding, or in the habituation of the peak startle response when compared to the non-prenatally stressed (CON) rats. However, PS rats have greater peak responses and longer latencies to reach the peak response following systemic doses of the 5-HT 1A agonist, 8-OH-DPAT, compared to CON rats. The PS rats had shorter latencies than the CON …

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Psychometric Properties Of The Social Interactions Questionnaire (Siq) In An Older Adult Sample, Kimberly Debra Kalish Dec 2001

Psychometric Properties Of The Social Interactions Questionnaire (Siq) In An Older Adult Sample, Kimberly Debra Kalish

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study examined the psychometric properties of the Social Interactions Questionnaire (SIQ; Kalish & Edelstein, 1996), a quick and efficient tool to measure negative social interactions. Overwhelming evidence has emerged over the past decade indicating that negative social interactions (NSIs) are strongly related to measures of mental and physical health. A critique of existing measures of NSIs reveals long and cumbersome interviews that are comprised of some, but not all, of the critical elements of NSIs. The SIQ efficiently measures these critical elements, which include (a) perceived versus structural components of NSIs, (b) seven different types of NSIs, (c) overall …

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Pharmacological Regulation Of C-Myc Gene Expression In Human Breast Cancer Cells, Zaroui Karlen Melkoumian Dec 2001

Pharmacological Regulation Of C-Myc Gene Expression In Human Breast Cancer Cells, Zaroui Karlen Melkoumian

Graduate Theses, Dissertations, and Problem Reports (ETD)

Previous studies demonstrated that quinidine causes G1/G0 cell cycle arrest and inhibition of proliferation in MCF-7 human breast cancer cell line (Woodfork, K. et al., 1995). The goal of studies reported here was to understand the molecular mechanisms of c-myc gene regulation by quinidine. C-myc is one of the most common oncogene aberrations in breast cancers (Deming, S. L. et al., 2000). C-myc functions include regulation of cell cycle, proliferation, differentiation, and apoptosis. The results of these studies demonstrated that quinidine causes rapid (within 1 hour) suppression of Myc protein and mRNA levels that precedes the quinidine-induced G1 cell cycle …

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Stand Dynamics And Disturbance History Of Five Oak -Dominated Old -Growth Stands In The Unglaciated Appalachian Plateau, James Spencer Rentch Dec 2001

Stand Dynamics And Disturbance History Of Five Oak -Dominated Old -Growth Stands In The Unglaciated Appalachian Plateau, James Spencer Rentch

Graduate Theses, Dissertations, and Problem Reports (ETD)

Stand dynamics and disturbance histories of five eastern, oak-dominated old-growth stands were investigated using ecological field sampling techniques, dendrochronologogical methods, and a review of historical resources of original forest composition and patterns of human and natural disturbance. Witness tree tallies from 18th century land surveys show that presettlement forests in the study areas were oak-dominated forests. Quercus alba was, at minimum, twice as abundant as Q. velutina, the second ranked species. Acer saccharum and Fagus grandifolia were among the top ten ranked species at each site; however their importance value was consistently less than one-third the value for Q. alba. …

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Synthesis Of Benzocarbazoles, Indoloquinolines And Indolonaphthridines From Thermolysis Of Benzoenynyl Ketenimines And Carbodiimides, Chongsheng Shi Dec 2001

Synthesis Of Benzocarbazoles, Indoloquinolines And Indolonaphthridines From Thermolysis Of Benzoenynyl Ketenimines And Carbodiimides, Chongsheng Shi

Graduate Theses, Dissertations, and Problem Reports (ETD)

The development of a general route to the N-[2-(1-alkynyl)phenyl]ketenimines (enyne-ketenimines) and N-[2-(1-alkynyl)phenyl]carbodiimides (enyne-carbodiimides) and their subsequent thermal behavior are described. Like enyne-allene and enyne-ketene systems, these enyne-hetereocumulenes undergo cycloaromatization through two competing biradical mechanisms under thermal conditions and therefore could serve as potential DNA cleaving agents. The resultant nitrogen-containing hetereocyclic compounds are also biologically interesting. The research described herein provides a easy access to the synthesis of benzo[b]carbazole, indoloquinoline and indolonaphthyridine alkaloids. In addition, the new synthetic strategies for these compounds are very versatile, providing access to a diverse array of analogs of these alkaloids.

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Transfer Of Heart Rate Feedback Training To Reduce Heart Rate Response To Laboratory Tasks, Jeffrey Louis Goodie Dec 2001

Transfer Of Heart Rate Feedback Training To Reduce Heart Rate Response To Laboratory Tasks, Jeffrey Louis Goodie

Graduate Theses, Dissertations, and Problem Reports (ETD)

Researchers have demonstrated that individuals can successfully reduce their heart rate (HR) response to a stressor when provided with heart rate feedback. However, it is unclear whether individuals can transfer HR reduction skills to stressors not used during HR feedback training. The present study used a multiple baseline, single subject design to examine the transfer of HR feedback training among six individuals. Participants were provided with HR feedback training during the presentation of a videogame, a mental arithmetic challenge, and a hand grip task until the participants reduced their HR to within 4 bpm of their resting HR or until …

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Chords Of Longest Circuits Of Graphs, Xuechao Li Dec 2001

Chords Of Longest Circuits Of Graphs, Xuechao Li

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis is on a long standing open conjecture proposed by one of the most prominent mathematicians, Dr. C. Thomassen: Every longest circuit of 3-connected graph has a chord. In 1987, C. Q. Zhang proved that every longest circuit of a 3-connected planar graph G has a chord if G is cubic or if the minimum degree is at least 4. In 1997, Carsten Thomassen proved that every longest circuit of 3-connected cubic graph has a chord.;In this dissertation, we prove the following three independent partial results: (1) Every longest circuit of a 3-connected graph embedded in a projective plane …

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Electrochemical Fabrication Of Semiconductor Nanostructure Arrays For Photonic Applications, Stephen Patrick Mcginnis Dec 2001

Electrochemical Fabrication Of Semiconductor Nanostructure Arrays For Photonic Applications, Stephen Patrick Mcginnis

Graduate Theses, Dissertations, and Problem Reports (ETD)

Theoretical and experimental investigations of the properties of semiconductor nanostructures have been an active area of research due to the enhanced performance that is observed when electrons and holes are spatially confined in one, two or three dimensions. However, the development of viable photonic devices using this phenomenon requires the development of appropriate fabrication techniques that can provide control over nanostructure size, material composition, and periodicity for structures with dimensions less than 20 nm. To address these challenges, a nanostructure synthesis technique has been developed that is based on the self-organization of nanometer scale pores during the anodization of aluminum …

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Women And Physical Culture In Modern Poland, Nameeta Mathur Dec 2001

Women And Physical Culture In Modern Poland, Nameeta Mathur

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation examines the interaction between the various forces of Polish "nationalism" and "feminism" in the construction of women's physical culture in modern Poland from the late nineteenth century until the end of the twentieth century. The basic premise of this work is that unlike most western countries where sportswomen have typically been marginalized in their athletic endeavors, Polish female athletes have earned far greater respect and recognition in the development of their physical culture. On many occasions, women's athleticism in Poland was a source of immense pride and prestige for both the state and society, albeit for varied reasons …

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Development Of Instrumentation For The Investigation Of Surface Regeneration For Candle Filters, Sean Patrick Gregory Dec 2001

Development Of Instrumentation For The Investigation Of Surface Regeneration For Candle Filters, Sean Patrick Gregory

Graduate Theses, Dissertations, and Problem Reports (ETD)

Two methods of improving efficiency of coal based power generation are integrated gasification combined-cycle (IGCC) and pressurized fluidized-bed combustion (PFBC). Both of these options require high-temperature gas stream particle cleanup for optimum efficiency. Candle filters in a pressurized vessel have received the greatest amount of attention in dealing with this topic, but problems still persist and there does not seem to be clear-cut answer to the problem. This research is an investigation of the candle filter cleaning process, a process known as surface regeneration.;The objective of this research program has been to develop the instrumentation necessary to investigate the surface …

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Optical Gradation For Crushed Limestone Aggregates, Ken Cheng Dec 2001

Optical Gradation For Crushed Limestone Aggregates, Ken Cheng

Graduate Theses, Dissertations, and Problem Reports (ETD)

The strength and durability of asphalt pavement is directly affected by the characteristics of its main ingredient, mineral aggregate. Besides material strength, research has shown that mixture properties such as particle shape and mixture gradation have a significant affect on the quality of the asphalt concrete. A standard called "Superpave" has been developed which sets forth specifications for material selection and methods for measurement of aggregate properties. These standards require monitoring of aggregate properties, particularly gradation. In this dissertation, the feasibility of developing an optically based method for determining aggregate gradation was explored. The physical system primarily consists of a …

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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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Potential Relations Between Extraversion And Cardiovascular Reactivity During Laboratory Stressors, Brandie K. Taylor Dec 2001

Potential Relations Between Extraversion And Cardiovascular Reactivity During Laboratory Stressors, Brandie K. Taylor

Graduate Theses, Dissertations, and Problem Reports (ETD)

This present study was designed to examine the relation between cardiovascular reactivity to stress and the behaviors of individuals classified as either "extraverts" or "introverts." Although experimental psychophysiological studies have been conducted to examine the relation between extraversion and physiological arousal, little is known about the ways in which extraversion and cardiovascular reactivity to stress are related. According to the optimal arousal theory, both extraverts and introverts would be expected to be more reactive to a social challenge than to a mundane non-social task, with introverts exhibiting greater reactivity to both tasks than extraverts. In contrast, a preferred task model …

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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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Conceptual Analysis Of A Four -Stroke Linear Engine, Sorin Petreanu Aug 2001

Conceptual Analysis Of A Four -Stroke Linear Engine, Sorin Petreanu

Graduate Theses, Dissertations, and Problem Reports (ETD)

During the past five years at West Virginia University, research into new auxiliary power generation devices has led to the development of a novel crankless reciprocating internal combustion engine. This dissertation presents a conceptual design of a Four-Stroke Linear Engine based on the numerical simulation of the operation of this type of linear engine. The engine consists of four opposed pistons linked by a connecting rod to a linear alternator. A series of numerical simulations was developed and employed to investigate the operation and performance of this crankless, four stroke linear engine. Since this linear engine is crankless, the numerical …

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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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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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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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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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Set-Theoretic And Algebraic Properties Of Certain Families Of Real Functions, Krzysztof Plotka Aug 2001

Set-Theoretic And Algebraic Properties Of Certain Families Of Real Functions, Krzysztof Plotka

Graduate Theses, Dissertations, and Problem Reports (ETD)

Given two families of real functions F1 and F2 we consider the following question: can every real function f be represented as f = f 1 + f2, where f1 and f2 belong to F1 and F2 , respectively? This question leads to the definition of the cardinal function Add: Add( F1,F2 ) is the smallest cardinality of a family F of functions for which there is no function g in F1 such that g + F is contained in F2 . This work is devoted entirely to the study of the function Add for different pairs of families of …

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Palladium -Catalyzed Synthesis Of Carbazole Derivatives And Formal Total Syntheses Of Several Naturally Occurring Carbazole Alkaloids, Tricia L. Scott Aug 2001

Palladium -Catalyzed Synthesis Of Carbazole Derivatives And Formal Total Syntheses Of Several Naturally Occurring Carbazole Alkaloids, Tricia L. Scott

Graduate Theses, Dissertations, and Problem Reports (ETD)

A mild and efficient route to substituted carbazolones has been developed. This novel procedure consists of two consecutive palladium-catalyzed reactions, an intermolecular Stille coupling followed by an intramolecular reductive N-heteroannulation. For example, 1,2-dihydro-4(3H)-carbazolone was prepared in good isolated yield (74%) by the reductive cyclization of 2-(2-nitrophenyl)-2-cyclohexen-1-one using Pd(dba)2 (6 mol%), 1,3-bis(diphenylphosphino)propane (6 mol%), 1,10-phenanthroline monohydrate (12 mol%), and carbon monoxide (90 psi) in DMF at 80°C. 2-(2-Nitrophenyl)-2-cyclohexen-1-one was prepared via a Stille coupling of 2-iodo-2-cyclohexen-1-one and 2-(tri-n-butylstannyl)-1-nitrobenzene. Many functional groups and ring sizes were tolerated in these reactions.;This novel approach to carbazolones was successfully applied to the formal total syntheses …

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Higher Order Chromatin Degradation Induced By Hydrogen Peroxide In Glial Cells, Raymond Mouzannar Aug 2001

Higher Order Chromatin Degradation Induced By Hydrogen Peroxide In Glial Cells, Raymond Mouzannar

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study addresses the genotoxicity of oxidative stress. We induced oxidative stress in cultured rat oligodendrocytes by exposure to hydrogen peroxide (H2O2). Intact genomic DNA was isolated by agarose embedding and its fragmentation was assessed by field inversion gel electrophoresis (FIGE). To detect single strand fragmentations, the DNA was digested with S1 nuclease before FIGE. We found that the exposure of oligodendrocytes to pathological concentrations of H2O2, induces a rapid digestion of nuclear chromatin in a pattern consistent with higher order chromatin degradation (HOCD). HOCD, the hallmark of programmed cell death (PCD), proceeds through single strand scissions that accumulate at …

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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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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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Effects Of Reinforcement Delays On Procrastination In Pigeons, Megan Elizabeth Meginley Aug 2001

Effects Of Reinforcement Delays On Procrastination In Pigeons, Megan Elizabeth Meginley

Graduate Theses, Dissertations, and Problem Reports (ETD)

Procrastination has been defined as the choice of a larger, later work requirement over a smaller, sooner work requirement. In one experiment (Mazur, 1996), pigeons chose a later-onset work requirement over an earlier-onset work requirement when work requirements were identical and reinforcement was at an equal delay from the choice point. In Phase I of the present experiment, reinforcement was delivered to pigeons immediately upon completion of either an early- or a late-onset work requirement in the terminal links of a concurrent-chains schedule. The early-onset work requirement was preferred. This preference held in Phase 2, when a delay to reinforcement …

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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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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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