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Graduate Theses, Dissertations, and Problem Reports (ETD)

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Processing And Characterization Of Contacts On Mbe-Grown Gallium Nitride, Carlo Requiao Da Cunha May 2001

Processing And Characterization Of Contacts On Mbe-Grown Gallium Nitride, Carlo Requiao Da Cunha

Graduate Theses, Dissertations, and Problem Reports (ETD)

Gallium nitride, a III-V compound semiconductor, is a good candidate for applications such as blue laser diodes and power devices due to its wide bandgap. One of the main challenges related to this compound is the growth of high quality crystals. If crystals with high level of purity are grown, the carrier concentration is therefore low, and the resulting high resistivity of the bulk imposes some difficulties for capacitance-related measurements. This thesis deals with the problem of processing and characterization of contacts on highly resistive materials such as unintentionally doped n-type gallium nitride. The ideal electrical model of a depletion …

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Mass Media Framing Of Hip-Hop Artists And Culture, Marc Allen Rutherford May 2001

Mass Media Framing Of Hip-Hop Artists And Culture, Marc Allen Rutherford

Graduate Theses, Dissertations, and Problem Reports (ETD)

The purpose of the mass news media is to inform individuals and society of important issues and events of the day. This coverage is influenced by the reporter's background, experience, time constraints, and a host of other factors. The way a reporter chooses to cover a particular story gives the story its slant or frame. Examining a cross section of media outlets from around the country gives a more complete picture of how a story is presented to society as a whole. Media coverage of hip-hop culture and the artists associated with it on a national level has been decidedly …

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Mitigation Of Water Quality And Ecosystem Impacts Of Roadway Construction Through Retrospective Engineering Analyses, Jaime Monique Sayre May 2001

Mitigation Of Water Quality And Ecosystem Impacts Of Roadway Construction Through Retrospective Engineering Analyses, Jaime Monique Sayre

Graduate Theses, Dissertations, and Problem Reports (ETD)

During the construction of a segment of Appalachian Corridor H between Buckhannon and Elkins, West Virginia, mine spoils and land use features related to historic mining were disturbed. An assessment of the water quality, benthic macro invertebrates, and fish populations was conducted to ascertain the condition of the water and to assess the biological productivity of Laurel Run, a tributary of the Tygart Valley River which runs parallel to Corridor H. The water quality and biological impairments were attributed to the ineffective vegetation of the spoils pile, which permitted water infiltration and thus, served as a source of metals and …

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Software Tool For Reliability Estimation, Manish Jhunjhunwala May 2001

Software Tool For Reliability Estimation, Manish Jhunjhunwala

Graduate Theses, Dissertations, and Problem Reports (ETD)

Reliability engineering is now an essential part of product development. In the area of electronics, reliability needs to be checked for each critical component before the product is shipped. Electronic products can range from computers to pace makers.;Over the years, several tools have been developed to estimate hardware/software reliability. Typically, such tools are either for hardware or software. This thesis presents a Software Tool for Reliability Estimation (STORE), which can be used for hardware components, software components, and for systems having both hardware and software components.;The objective of this research was to study several hardware-software reliability models, existing algorithms to …

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Direct Liquefaction Of Coal With Coal-Derived Solvents To Produce Precursors For Carbon Products, David Christopher Fenton May 2001

Direct Liquefaction Of Coal With Coal-Derived Solvents To Produce Precursors For Carbon Products, David Christopher Fenton

Graduate Theses, Dissertations, and Problem Reports (ETD)

Direct liquefaction (hydrogenation) of coal has frequently been pursued as one avenue for the production of value added products from coal. The focus of this research was to evaluate five coal-derived liquids as substitutes for tetralin in the coal hydrogenation process. A mid-distillate by-product liquid from the production of high quality char was obtained from Antaeus Technical Services, Inc. and split into three fractions, the original liquid (RACL), its heavy fraction (DACL-H), and its light fraction (DACL-L). The other two liquids were heavy creosote oil (HCO) and carbon black base #1 (CBB) from Koppers Industries, Inc. These liquids were used …

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Computer Usage By Building -Level Administrators In West Virginia Public Schools, Kevin Gail Cain May 2001

Computer Usage By Building -Level Administrators In West Virginia Public Schools, Kevin Gail Cain

Graduate Theses, Dissertations, and Problem Reports (ETD)

By gaining a better understanding of the general computer usage of building-level administrators, effective training programs can be designed to enhance the leadership roles of the school principal. Administrators, supervisors, directors, and program coordinators at the West Virginia Department of Education will be able to use the information found through this study to assist administrators in becoming more effective leaders within their respective schools. More effective leaders will lead to more effective schools. Further, the technologically literate principal will be better equipped to take on a more active role in the technological advancements at his/her respective school.;The purpose of this …

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Comparison Study Of The Savings Between A Single And A Double Step Toll Systems, Juan Arturo Kuthy-Saenger May 2001

Comparison Study Of The Savings Between A Single And A Double Step Toll Systems, Juan Arturo Kuthy-Saenger

Graduate Theses, Dissertations, and Problem Reports (ETD)

Solving the problem of highway congestion requires solutions that go beyond the capacity expansion of the roadway and towards effective capacity expansion though innovative operations of facilities. One such innovation is the implementation of congestion tolls in order to set volume levels at economically optimal levels. Transportation researches, for some time, have known the potential of congestion tolls as one solution to the congestion problem, and we are now seeing several cases of facilities operating under a congestion toll. However, essentially all of these cases operate under a single toll, i.e. the toll is fixed and does not change with …

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Time-Dependent Circumferential Deformation Of Cortical Bone Subjected To Internal Radial Loading, Christopher Uriah Brown May 2001

Time-Dependent Circumferential Deformation Of Cortical Bone Subjected To Internal Radial Loading, Christopher Uriah Brown

Graduate Theses, Dissertations, and Problem Reports (ETD)

Human cortical bone is a complex composite material that displays time-dependent deformation. The response of bone to loads in the transverse orientation is not well understood and has implications to the stability of a press-fit hip implant. Total hip arthroplasty is a surgical procedure to replace the hip joint. It involves inserting an implant into the shaft of the femur. One method of implant fixation is a press-fit of the implant into the bone canal. Press-fit fixation relies on the elastic response of the proximal femur to hold the implant in place until new bone growth occurs. The radial load …

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Multimedia -Assisted Reading In Spanish And Its Relationship With The Cognitive Control Of Field Dependence And Field Independence, Laura Janes Little May 2001

Multimedia -Assisted Reading In Spanish And Its Relationship With The Cognitive Control Of Field Dependence And Field Independence, Laura Janes Little

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study examines the influence of the cognitive controls of field independence and field dependence on the use of a multimedia-assisted reading program and reading recall. The participants were 11 university students of intermediate Spanish as a second language. The participants were classified as field dependent or field independent based on GEFT scores. The participants read a passage about Mayan architecture that was converted to a multimedia-assisted format. Participants could access as many or as few of the multimedia aids as they chose. After completing the reading, a recall measure was obtained in which participants wrote everything they could recall …

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Effects Of Work Stoppages At Selected Steel Mills On Production And Safety Systems, Daniel Hartley May 2001

Effects Of Work Stoppages At Selected Steel Mills On Production And Safety Systems, Daniel Hartley

Graduate Theses, Dissertations, and Problem Reports (ETD)

The purpose of this research was to identify if there was a significant difference between the OSHA recordable incidence rates at a selected steel manufacturer prior to a major work stoppage and subsequent to the work stoppage. Monthly and quarterly time periods were evaluated to determine the level of change that occurred between prior and post work stoppage periods. Raw steel production was also evaluated to determine the effects of the work stoppage on production totals. OSHA recordable incidence rates were generally lower after the work stoppage, while production totals were higher after the work stoppage. In many instances the …

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Fastener Withdrawal Resistance Of Wood-Based Composite Panel Products, Steven M. Cook May 2001

Fastener Withdrawal Resistance Of Wood-Based Composite Panel Products, Steven M. Cook

Graduate Theses, Dissertations, and Problem Reports (ETD)

The purpose of this research project was to evaluate the performance of currently available wood-based panel products as sub-floor materials when used under quality oak strip flooring and exposed to cyclic EMC conditions. The critical evaluation criterion was the fastener holding capacity of various sub-floor materials. To accomplish this, investigation of the in-plane density variations of currently available panel products was performed, as was an investigation of the relationship between panel density and the fastener holding capacity of different panel materials. In addition, a comparison of the fastener holding capacity of six different panel products was investigated during and after …

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Wood Deck Bridges-Stress Laminated Wood Panels On Steel Beams, Bryan Lin King May 2001

Wood Deck Bridges-Stress Laminated Wood Panels On Steel Beams, Bryan Lin King

Graduate Theses, Dissertations, and Problem Reports (ETD)

The objective of this project was to simulate a stress laminated timber bridge deck model stiffened with wide flange steel stringers for performance monitoring. The simulation accounted for typical HS-20 repetitive loadings offered by a mechanically controlled actuator.;Based on the results incorporated in this report and additional projects accredited in the literature review, some general recommendations can be established regarding the best approach for constructing timber bridges in the future.;In general, short span prestressed timber bridges appear to be a reliable alternative in rural bridge design applications. Pure aesthetics responsive to timber construction add to the allure of this optional …

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Development Of An Apparatus To Quantify The Volitional Muscle Performance Of Rat Plantar Flexors In Vivo, Vineet Shastri May 2001

Development Of An Apparatus To Quantify The Volitional Muscle Performance Of Rat Plantar Flexors In Vivo, Vineet Shastri

Graduate Theses, Dissertations, and Problem Reports (ETD)

An in vivo animal model was developed to study the effects of voluntary eccentric, concentric, and isometric muscle actions and varying work-rest cycles on muscle performance, behavior, and histological and biochemical response. Using a custom-designed apparatus that was attached to a standard operant chamber, rats were operantly conditioned with food rewards to perform a voluntary lifting task to generate controlled movement of the plantar flexors. An opening in the front panel of the operant chamber allowed the rat to enter a Plexiglas tube that was mounted vertically to restrict the movement of the rat. A load cell was embedded in …

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Relational Specification As A Testing Oracle, Harjinder Sandhu May 2001

Relational Specification As A Testing Oracle, Harjinder Sandhu

Graduate Theses, Dissertations, and Problem Reports (ETD)

Software engineering community is well aware of the usefulness of formal methods for specifying, designing and testing of the software. Despite this testing literature rarely deals with specification based testing. Testing from formal specifications offers a simple, structured and more rigorous approach to the functional tests than testing techniques. An important application of specification in testing is providing test oracles. The rise of use of computers in control safety critical systems, i.e., flight control systems, necessitates that rigorous system testing is performed before the deployment. In flight control systems, requirements are mostly concerned with the safety and maneuverability of an …

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Teaching Web Design At The Higher Education Level, Randall Franklin Mull May 2001

Teaching Web Design At The Higher Education Level, Randall Franklin Mull

Graduate Theses, Dissertations, and Problem Reports (ETD)

For the latter half of the last decade the new phenomenon known as the Internet has taken over media and journalism in many ways. It has changed the way that news and information is delivered to the public. It has made people also perceive the media in a new way. The public now, more than ever, demands information fast and accurately.;That is why it is critical that students of journalism today learn about this new tool which they can use to their advantage. In order to address this need within the P. I. Reed School of Journalism a new course …

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Scheduling Flexible Flowshops With Sequence -Dependent Setup Times, Kanchana Sethanan May 2001

Scheduling Flexible Flowshops With Sequence -Dependent Setup Times, Kanchana Sethanan

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation addresses the scheduling problem in a flexible flowshop with sequence-dependent setup times. The production line consists of S production stages, each of which may have more than one non-identical (uniform) machines. Prior to processing a job on a machine at the first stage, a setup time from idling is needed. Also sequence dependent setup times (SDST) are considered on each machine in each stage. The objective of this research is to minimize the makespan. A mathematical model was developed for small size problems and two heuristic algorithms (Flexible Flowshop with Sequence Dependent Setup Times Heuristic (FFSDSTH) and Tabu …

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Studies Of The Initial Stage Of Silicon Carbide Growth On Silicon, Katherine Stewart Ziemer May 2001

Studies Of The Initial Stage Of Silicon Carbide Growth On Silicon, Katherine Stewart Ziemer

Graduate Theses, Dissertations, and Problem Reports (ETD)

The lack of understanding concerning the initial stage of silicon carbide (SiC) growth on silicon (Si) substrates gives rise to heated debates on the growth mechanisms, the characteristics of the "optimal" initial layers, and the processing parameters necessary to produce high-quality cubic or beta silicon carbide (beta-SiC) on these initial layers. If the potential of beta-SiC as a semiconductor for electronic devices is to be realized, the growth of the initial layers (i.e. the initial stage of growth) must be understood and then controlled.;This dissertation presents results from the comparison of the initial stages of beta-SiC growth by gas source …

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Sensor Technology For The Breast Examination Training Instrument, Bratislav Matic May 2001

Sensor Technology For The Breast Examination Training Instrument, Bratislav Matic

Graduate Theses, Dissertations, and Problem Reports (ETD)

Latest medical research has shown high percentage of American women, diagnosed with breast cancer. If detected in its early stage, cancer can be treated successfully. Breast examination might be obtained through three procedures: breast self-examination (BSE), clinical breast examination (CBE) and mammography. Project BETI was developed with idea of educating and training women and health care professionals in BSE. This instrument consists of a silicone breast model, tactile sensors and serial communication capability. Software was developed for a generic PC that supports an integrated system including: (1) an interactive video demonstrating BSE techniques, (2) a practical examination using the instrumented …

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Computational Modeling Of Hydrogen Embrittlement Of Iron Aluminides, Roxana Cisloiu May 2001

Computational Modeling Of Hydrogen Embrittlement Of Iron Aluminides, Roxana Cisloiu

Graduate Theses, Dissertations, and Problem Reports (ETD)

Comparative fracture tests of two Fe-28%Al iron aluminides revealed that alloys with B, Zr, and C addition (FA189) are extrinsically more susceptible to environmental embrittlement than the base ternary alloy (FA186) under constant tensile loading condition. This may due to the effect of smaller grain sizes caused by alloy addition. To further investigate the grain boundary size effect as related to the susceptibility of hydrogen embrittlement, comparative finite element modeling simulations of intergranular fracture of two iron aluminides (FA186 and FA189) were carried out. The computational simulations involved sequentially coupled stress and hydrogen diffusion analyses to determine crack-tip stress state …

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Scenario-Based Verification And Validation Of Dynamic Uml Specifications, Alaa El-Sayed Ibrahim May 2001

Scenario-Based Verification And Validation Of Dynamic Uml Specifications, Alaa El-Sayed Ibrahim

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Unified Modeling Language (UML) is the result of the unification process of earlier object oriented models and notations. Verification and validation (V&V) tasks, as applied to UML specifications, enable early detection of analysis and design flaws prior to implementation. In this work, we address four V&V analysis methods for UML dynamic specifications, namely: Timing analysis and automatic V&V of timing constraints, automated Architectural-level Risk assessment, Performance Modeling and Fault Injection analysis. For each we present: approaches, methods and/or automated techniques. We use two case studies: a Cardiac Pacemaker and a simplified Automatic Teller Machine (ATM) banking subsystem, for illustrating …

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Analyses Of Coal Extraction And Spoil Handling Techniques In Mountainous Areas, Shiva Prasad B. Kolli May 2001

Analyses Of Coal Extraction And Spoil Handling Techniques In Mountainous Areas, Shiva Prasad B. Kolli

Graduate Theses, Dissertations, and Problem Reports (ETD)

Surface mining of multiple seams by mountaintop mining methodology is complex in the Appalachian region of West Virginia. Mining operations in these mountainous areas can be considered as customized forms of surface mining techniques. The customization of the mining methods is greatly dominated by the location, geology, and stratigraphic succession of coal seams in the area.;Owing to its unique mining operations, and the environmental effects associated with it, mountaintop removal method of mining has become an issue of public concern. The pertinence of the present mountaintop mining operations and reclamation techniques, with respect to being in compliance with Surface Mining …

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Design And Simulation Of High-Performance Hybrid Electric Vehicle Powertrains, Samuel P. Taylor May 2001

Design And Simulation Of High-Performance Hybrid Electric Vehicle Powertrains, Samuel P. Taylor

Graduate Theses, Dissertations, and Problem Reports (ETD)

The intent of this study was the design, modeling, and simulation of several high-performance light-duty hybrid electric vehicle powertrains. The design requirements of each proposed configuration are to meet or exceed a set of performance baselines based on a composite set of particular high-performance conventional vehicles presently available, while demonstrating increased fuel efficiency over regulated government cycles.;Several hybrid powertrain configurations were studied; however, the most promising and feasible for production designs were selected for further modeling. All of the proposed designs are post-transmission parallel hybrids for primarily performance reasons, with the auxiliary motive power coming after the transmission, utilizing a …

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Cmos Fingerprint Sensor Electrostatic Modeling, Praveen Kumar Soora May 2001

Cmos Fingerprint Sensor Electrostatic Modeling, Praveen Kumar Soora

Graduate Theses, Dissertations, and Problem Reports (ETD)

The use of Biometrics in personal identification is an important emerging technology in modern electronic society. Fingerprints are one of the most popular biometric technologies, currently used in majority of biometric applications. In recent years, solid-state capacitive fingerprint sensors which image fingerprints using Silicon CMOS Technology are gaining much acceptance in the market. This research work is carried out to quantify and explore approaches for achieving improved sensitivity of the capacitive imaging process through reduction of parasitic capacitances and sensor cell scaling for future generation devices. Evaluation of sensor cell and array geometries was completed using a commercial 2-D electrostatic …

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Stress Concentration Around Dowel Bars In Jointed Rigid Concrete Pavements, Mourad Youssef Riad May 2001

Stress Concentration Around Dowel Bars In Jointed Rigid Concrete Pavements, Mourad Youssef Riad

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this study, the magnitude and state of stresses induced around dowel bars were identified through detailed 3D Finite Element (3DFE) modeling of dowel jointed rigid pavement structures. Both straight and skewed joints were modeled using extremely fine meshing that allows accurate modeling of the friction and separation at dowel concrete interfaces. The model response was examined for the case of joint loading with an equivalent axle load of 18000 lb. It was found that significantly large tensile stresses develop in the concrete on both sides of the loaded dowel. The magnitude of the tensile stress approaches the tensile modulus …

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Propagation Of Updates To Replicas Using Error-Correcting Codes, Karthik Palaniappan May 2001

Propagation Of Updates To Replicas Using Error-Correcting Codes, Karthik Palaniappan

Graduate Theses, Dissertations, and Problem Reports (ETD)

With the increase in percentage of replicas of data in the Internet, reducing the amount of bandwidth needed for propagation of updates across the replicas has become a major issue. Objective of our investigation is to design an update propagation mechanism focused on reducing the amount of bandwidth needed to propagate the change across multiple distinct versions of the replicas in a distributed system. We obtain the estimated amount of bytes changed from the user and generate parity information needed to correct these bytes using Error Correcting Codes. Transferring the parity information propagates the update. The updated data can be …

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Evaluation Of Exhaust Flowrate Measurement Techniques For A Mobile Emissions Monitoring System, Eric Todd Meyer May 2001

Evaluation Of Exhaust Flowrate Measurement Techniques For A Mobile Emissions Monitoring System, Eric Todd Meyer

Graduate Theses, Dissertations, and Problem Reports (ETD)

West Virginia University designed and developed Mobile Emissions Monitoring System (MEMS) for the six settling Heavy-Duty Diesel Engine (S-HDDE) manufacturers. The MEMS measures emissions concentrations while operating in a real world environment. The best method for measuring the emissions concentrations was found to be through raw exhaust sampling. In order to properly calculate the emissions concentrations the total exhaust flowrate through the engine must be determined. The devices evaluated were an Annubar, an Accutube, a hot film anemometer, a Pitot static tube, a venturi, and a vortex shedder.;The evaluation of the devices was broken down into two parts, the first …

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Design And Evaluation Of The Emissions Measurement Components For A Heavy-Duty Diesel-Powered Vehicle Mobile Emissions Measurement System (Mems), Wesley Clark Riddle May 2001

Design And Evaluation Of The Emissions Measurement Components For A Heavy-Duty Diesel-Powered Vehicle Mobile Emissions Measurement System (Mems), Wesley Clark Riddle

Graduate Theses, Dissertations, and Problem Reports (ETD)

The objective of this study was the design, construction, and preliminary qualification of the Mobile Emissions Measurement System (MEMS) for in-use, on-road testing of heavy-duty diesel-powered vehicles. This included selection of emissions analyzers and sampling system components capable of producing emissions results of similar accuracy to those attained with laboratory-grade instruments. A thorough investigation of commercially available systems, and a literature review, identified no suitable designs. Therefore, a complete emissions measurement system, designed specifically for the testing of heavy-duty diesel powered vehicles, was developed using available components.;The candidate analyzers that performed successfully during bottled gas bench tests were then incorporated …

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Dsp Implementation Of Trellis Coded Modulation And Distributed Space Time Coding, Yipeng Tang May 2001

Dsp Implementation Of Trellis Coded Modulation And Distributed Space Time Coding, Yipeng Tang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Trellis coded modulation (TCM) combines convolutional coding with modulation, and offers approximately 2--3 dB of coding gain without requiring a corresponding bandwidth expansion. This thesis describes the process of encoding TCM, convolutional codes, decoding using the Viterbi Algorithm (VA), M-ary modulation formats suitable for TCM, and the evaluation of TCM performance.;The concept of multiple TCM, which is a generalization of ordinary TCM, gives rise to the concept of space time codes (STC). With STC, coded signals are transmitted from multiple antennas at the same time over a Rayleigh fading channel. STC combines of transmit diversity, coding and M-ary modulation to …

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Pretreatment And Enzymatic Hydrolysis Of Lignocellulosic Materials, Wei Cheng May 2001

Pretreatment And Enzymatic Hydrolysis Of Lignocellulosic Materials, Wei Cheng

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research aims to increase the efficiency of utilizing lignocellulosic materials, which have great potential as future energy and chemical feed stocks, and may finally substitute the diminishing hydrocarbon resources. This work involved two main parts: (a) comparison of efficiency of different pretreatment methods on lignocellulosic materials; and (b) enhancing enzymatic hydrolysis in a continuous tubular membrane reactor (TMR) process.;The alkaline oxidation pretreatment method was found to be more efficient than ammonia steeping pretreatment in lignin removal and digestible cellulose enrichment for the raw substrates chosen for this study, namely, yellow poplar (hardwood) and corn cob (herbaceous crop).;A combination of …

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Optimum Hybrid Vehicle Configurations For Heavy Duty Applications, Jonathan Burke Smith May 2001

Optimum Hybrid Vehicle Configurations For Heavy Duty Applications, Jonathan Burke Smith

Graduate Theses, Dissertations, and Problem Reports (ETD)

Increased concern about the fuel economy of and emissions from automobiles has led to interest in the use of hybrid electric powertrains and the introduction of several production vehicles in both heavy-duty and light-duty applications. Hybrid electric vehicles (HEVs) use a combination of electric motor(s) and another power source such as an internal combustion engine (ICE) or fuel cell. While these vehicles show great potential for use in a wide variety of driving situations, the optimization of components and control strategies is quite complex.;In this thesis, Class 2B, Class 6, and Class 8 vehicles are determined by averaging a variety …

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