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Articles 1501 - 1530 of 2035

Full-Text Articles in Engineering

Ultracapacitor Heavy Hybrid Vehicle: Model Predictive Control Using Future Information To Improve Fuel Consumption, Seneca Schepmann Aug 2010

Ultracapacitor Heavy Hybrid Vehicle: Model Predictive Control Using Future Information To Improve Fuel Consumption, Seneca Schepmann

All Theses

This research is concerned with the improvement in the fuel economy of heavy transport vehicles through the use of high power ultracapacitors in a mild hybrid electric vehicle platform. Previous work has shown the potential for up to 15% improvement on a hybrid SUV platform, but preliminary simulations have shown the potential improvement for larger vehicles is much higher.
Based on vehicle modeling information from the high fidelity, forward-looking modeling and simulation program Powertrain Systems Analysis Toolkit (PSAT), a mild parallel heavy ultracapacitor hybrid electric vehicle model is developed and validated to known vehicle performance measures. The vehicle is hybridized …

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Surface Characterization And Electrochemical Behavior Of Colloidal Particles, Cinta Pepin Aug 2010

Surface Characterization And Electrochemical Behavior Of Colloidal Particles, Cinta Pepin

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There is an ongoing interest in research focused on developing polymeric organic-light-emitting-devices (OLED) to replace inorganic devices. Compared to inorganic devices, OLEDs could present better properties such as higher efficiency, lower cost and simpler device fabrication. In an attempt to get a device with high efficiency, the hole transporting group and the electron transporting group were combined into a polymer to make an individual 'particle device'. The idea was to create a polymer particle containing both charge transporting moieties via emulsion polymerization. In this presentation, different techniques will be described that were used to determine the stability and the surface …

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Fabrication Of Fluorescent Nanoparticle-Polymer Composites For Photoactive-Based Materials, Brett Ellerbrock Aug 2010

Fabrication Of Fluorescent Nanoparticle-Polymer Composites For Photoactive-Based Materials, Brett Ellerbrock

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Nanocomposites of nanoparticles dispersed throughout a polymer matrix have been studied to great length to improve the overall polymer properties. These enhancements are observed in the thermal, physical, and/or optical characteristics. Being able to harness nanoparticles in such a way may help improve fiber technology into the 21st century.
This work was geared toward synthesizing rare earth doped lanthanum fluoride (LaF3) nanoparticles because good separation in the absorption and emission bands of the material and it fluoresces in the visible to near-infrared range. Terbium ions were added to a LaF3 crystal because of their distinct visible green …

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Infrared Thermography And Ultrasonic Inspection Of Adhesive Bonded Structures, Overview And Validity, Suhas Vedula Aug 2010

Infrared Thermography And Ultrasonic Inspection Of Adhesive Bonded Structures, Overview And Validity, Suhas Vedula

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The work focuses on establishing a relationship between two different techniques of Nondestructive testing, namely Infrared Thermography and Ultrasonic Inspection. The integration of the two testing techniques is done with an expectation to achieve accurate characterization and determination of internal defects in adhesive bonded structures.
Experiments are done on sandwich samples with defects using various ultrasonic testing methods like pulse-echo and immersion techniques. The results thus obtained are documented and location of the defects is marked. The same samples are then tested using Infrared thermography to visualize the defects.
The results obtained by both the methods are compared to check …

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Non-Contact Spatially Constrained Optical Scanning Methods Applied For Depth, Width And Gap Measurements, Konda Reddy Thotti Reddy Aug 2010

Non-Contact Spatially Constrained Optical Scanning Methods Applied For Depth, Width And Gap Measurements, Konda Reddy Thotti Reddy

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The thesis presents the non-contact laser projection based systems utilized for quantifying the feature dimensions like width, depth and air gaps. Laser diode, Charge coupled device (CCD) and post-processing software using image processing tools are the major components of the non-contact measurement systems. The study involves two methods where the first method comprises of active laser-based triangulation and morphological edge detection for depth and width measurement applications. The second method uses edge detection technique and Dynamic Field of View (DFOV) for gap detection and tracking. Using the developed techniques, the case studies are conducted with smooth plastic fenders with induced …

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Catalysis Of Ethanol Synthesis From Syngas, Jia Gao Aug 2010

Catalysis Of Ethanol Synthesis From Syngas, Jia Gao

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Catalytic synthesis of ethanol and other higher alcohols from CO hydrogenation has been a subject of significant research since the 1980s. The focus of this research is to establish a better fundamental insight into heterogeneous catalysis for CO hydrogenation reactions, in an attempt to design the best catalysts for ethanol synthesis.
It has been reported widely that promoted Rh-based catalysts can exhibit high selectivity to C2+ oxygenates during CO hydrogenation. The doubly promoted Rh-La-V/SiO2 catalysts exhibited higher activity and selectivity for ethanol and other C2+ oxygenates than singly promoted catalysts. The better performance appears to be due to a synergistic …

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Development Of Experimental Methods To Assess Adsorption Free Energy For Peptide-Surface Interactions, Yang Wei Jul 2010

Development Of Experimental Methods To Assess Adsorption Free Energy For Peptide-Surface Interactions, Yang Wei

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Because of its governing role in cellular response to implants and substrates for biomedical applications, the understanding and control of protein adsorption to material surfaces has been one of the major topics of research in the field of biomaterials. Unfortunately, it has proven to be extremely difficult to quantitatively understand and control these types of interactions because of the complexities involved, and existing methods that have been developed and used to characterize protein-surface interactions have proved to be inadequate to provide the level of detail necessary to achieve this understanding. New, more fundamental methods, both experimental and computational, are needed …

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Cell-Mediated Elastic Matrix Regeneration Toward Regression Of Abdominal Aortic Aneurysms, Carmen Gacchina Jun 2010

Cell-Mediated Elastic Matrix Regeneration Toward Regression Of Abdominal Aortic Aneurysms, Carmen Gacchina

All Dissertations

Abdominal aortic aneurysms (AAAs) are typically fusiform (symmetric) dilations of the aortic wall most commonly arising below the renal arteries. The progression is typically associated with an activated smooth muscle cell (SMC) phenotype, diminished density of mature medial elastic fibers, and an elevated presence of matrix-degrading enzymes (e.g., matrix-metalloproteases; MMPs), which may ultimately lead to vessel rupture. Currently, no surgical or non-surgical methods are available to regress AAAs via regeneration of new elastin matrices to regain normal vessel contour, particularly due to the inherently poor elastin synthesis by adult vascular cells and absence of methods to stimulate the same. Previously, …

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Fabrication Of Transparent Ceramic Laser Media For High Energy Laser Applications, Karn Serivalsatit May 2010

Fabrication Of Transparent Ceramic Laser Media For High Energy Laser Applications, Karn Serivalsatit

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Sesquioxides of yttrium, scandium, and lutetium, i.e., Y2O3, Sc2O3, and Lu2O3, have received a great deal of recent attention as potential high power solid state laser hosts. These oxides are receptive to lanthanide doping, including trivalent Er, Ho and Tm which have well known emissions at eye-safe wavelengths that can be excited using commercial diode lasers. These sesquioxides are considered superior to the more conventional yttrium aluminum garnet (YAG) due to their higher thermal conductivity, which is critical for high power laser system. Unfortunately, these oxides possess high …

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Occurrence And Formation Of Disinfection By-Products In Indoor Swimming Pools Water, Amer Kanan May 2010

Occurrence And Formation Of Disinfection By-Products In Indoor Swimming Pools Water, Amer Kanan

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Chlorination is used to prevent the spread of waterborne infectious diseases from swimming pools. This required disinfection practice also results in the formation of undesirable disinfection by-products (DBPs) from the reactions of chlorine with the organic matter (released by swimmers or present in the filling water of the pool) and bromide. Some of these DBPs have important adverse public health effects; as a result their concentrations in drinking waters are regulated. Unfortunately, DBPs formation and control in swimming pools have not been studied and investigated to the same extent as their formation and control in drinking water.
The main objective …

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Software Algorithms To Coordinate And Improve Voltage Sag Ridethrough Capabilities Of Networked Industrial Processes, Owen Parks May 2010

Software Algorithms To Coordinate And Improve Voltage Sag Ridethrough Capabilities Of Networked Industrial Processes, Owen Parks

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For those who design, operate, and troubleshoot industrial processes, electric power quality is a subject that requires much consideration. Processes that use electronic sensors, actuators, and computation devices are heavily reliant on a stable, consistent input power source. When a power quality event such as a voltage fluctuation occurs, automation equipment often behaves unpredictably and causes process malfunction or failure.
Because industrial power consumers often blame their electric utility for these events, some utilities offer process susceptibility studies as a service for their customers. During a typical study, utility technicians and engineers perform in-house tests on suspect components or systems …

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Vehicle Steering Systems - Hardware-In-The-Loop Simulator, Driving Preferences, And Vehicle Intervention, Jesse Black May 2010

Vehicle Steering Systems - Hardware-In-The-Loop Simulator, Driving Preferences, And Vehicle Intervention, Jesse Black

All Dissertations

The steering system is a critical component of all ground vehicles regardless of their propulsion source. Chassis directional control is provided by the steering system, which in turn relays valuable feedback about the road and vehicle behavior. As the primary feedback channel to the driver, the steering system also delivers the initial perception of a vehicle's handling and responsiveness to the consumer. Consequently, the steering system is an important aspect of the vehicle's evaluation and purchasing process, even if drivers are unaware of its direct influence in their decision making. With automobile purchases potentially hinging on the steering system, a …

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Cross-Layer Scheduling Protocols For Mobile Ad Hoc Networks Using Adaptive Direct-Sequence Spread-Spectrum Modulation, Brian Wolf May 2010

Cross-Layer Scheduling Protocols For Mobile Ad Hoc Networks Using Adaptive Direct-Sequence Spread-Spectrum Modulation, Brian Wolf

All Dissertations

We investigate strategies to improve the performance of transmission schedules for mobile ad hoc networks (MANETs) employing adaptive direct-sequence spread-spectrum (DSSS) modulation. Previously, scheduling protocols for MANETs have been designed under the assumption of an idealized, narrowband wireless channel. These protocols perform poorly when the channel model incorporates distance-based path loss and co-channel interference. Wideband communication systems, such as DSSS systems, are more robust in the presence of co-channel interference; however, DSSS also provides multiple-access capability that cannot be properly leveraged with a protocol designed for narrowband systems. We present a new transmission scheduling protocol that incorporates link characteristics, spreading …

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Grain Boundary Premelting And Activated Sintering In Binary Refractory Alloys, Xiaomeng Shi May 2010

Grain Boundary Premelting And Activated Sintering In Binary Refractory Alloys, Xiaomeng Shi

All Dissertations

Quasi-liquid intergranular film (IGF) which has been widely observed in ceramic systems can persist into sub-solidus region whereby an analogy to Grain boundary (GB) premelting can be made.
In this work, a grain boundary (GB) premelting/prewetting model in a metallic system was firstly built based on the Benedictus' model and computational thermodynamics, predicting that GB disordering can start at 60-85% of the bulk solidus temperatures in selected systems. This model quantitatively explains the long-standing mystery of subsolidus activated sintering in W-Pd, W-Ni, W-Co, W-Fe and W-Cu, and it has broad applications for understanding GB-controlled transport kinetics and physical properties. Furthermore, …

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Isolating Petroleum Pitch Oligomers Via Multistage Supercritical Extraction, Eduardo Cervo May 2010

Isolating Petroleum Pitch Oligomers Via Multistage Supercritical Extraction, Eduardo Cervo

All Dissertations

Petroleum pitches are carbonaceous materials that serve as precursors for advanced carbon products. Because of their highly graphitic nature, such pitches are of particular interest for producing high thermal conductivity carbon fibers for thermal management applications, such as microelectronics packaging for hybrid and plug-in vehicles.
Even though the properties of the final carbon products are impacted by the molecular composition of the starting pitch precursor, a fundamental understanding of this relationship has yet to be established. To this end, dense-gas extraction (DGE), a fractionation technique that allows for the production of pitches of controlled composition for both analytical and rheological …

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An Integral Equation Analysis Of A Two-Aperture Coaxial Waveguide, John Luke May 2010

An Integral Equation Analysis Of A Two-Aperture Coaxial Waveguide, John Luke

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Two different, two-aperture coaxial waveguide configurations are modeled. Integral equations are formulated and then solved by means of the Method of Moments. The results of the analyses are used to formulate a microwave network representation for each structure. Commercial electromagnetic modeling software, along with data acquired through the building and testing of one of the structures, is used to prove the validity of the solution technique developed within the text.

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Re-Engineering A Trash/Recycling Collection Vehicle Based On Challenging Customer Requirements, Edward Smith May 2010

Re-Engineering A Trash/Recycling Collection Vehicle Based On Challenging Customer Requirements, Edward Smith

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Engineering design starts with the definition of design requirements. These requirements define the design problem and must be satisfied for a solution to be acceptable. While many design methodologies exist for defining design requirements, none presently provides a systematic approach for designers to challenge requirements. Yet, Pahl and Beitz, Hazelrigg, and Suh all argue that a designer should continually question the need for each requirement and refine them as the product evolves. Thus, there exists a need to develop a comprehensive method that enables a designer to verify, review/question, and revise requirements throughout the design process. This research uses the …

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Sensitivity Constrained Pmu Placement Utilizing Multiple Methods, Zheng Zhao May 2010

Sensitivity Constrained Pmu Placement Utilizing Multiple Methods, Zheng Zhao

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Phasor Measurement Unit (PMU), which is based on the GPS technique, is able to provide power engineers with immediate and precise measurements. By utilizing PMUs, the reliability and stability in power system are expected to be improved. Conventionally, an optimal PMU placement is considered to use the least number of units to make the entire system completely observable. In this thesis, it is recommended to not only optimize the number of PMUs but also install the majority of PMUs on the most sensitive buses in a power system. Thus a bus sensitivity analysis based on Decoupled Power Flow method is …

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Biodegradable Polymer Blends And Composites From Proteins Produced By Animal Co-Product Industry, Bernice Nzioki May 2010

Biodegradable Polymer Blends And Composites From Proteins Produced By Animal Co-Product Industry, Bernice Nzioki

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ABSTRACT
Development of new green materials from by-products of animal rendering industries would provide a substantial economic return to animal rendering processors. Meat and bone meal (MBM), one of the products of the rendering industry, has potential for numerous bio-based applications. This research focuses on fabrication of plastics blends made of MBM (Meat and bone meal) and UHMWPE (ultra high molecular weight polyethylene). We investigated thermal, morphological, water absorption and mechanical properties of the plastics. The plastics were compression molded and their properties were examined.
DSC thermographs of the blends indicated that the thermal properties of UHMWPE did not change …

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An Assessment Of Linear Wrist Motion During The Taking Of A Bite Of Food, Meredith Drennan May 2010

An Assessment Of Linear Wrist Motion During The Taking Of A Bite Of Food, Meredith Drennan

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Motivated by the goal of building a device capable of detecting when a user takes a bite of food, we examine whether there is a correlation between linear wrist motion and bite detection. Such a device could be used to manage weight loss by tracking eating trends over time and providing real time feedback to the user regarding eating rate or total consumption. A comprehensive analysis of tracking linear motion using low cost inertial sensors is presented. Based on this theory, we discuss the design and tracking accuracy of a prototype bite counting device. We show that tracking position using …

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Comparision Of Open Graded Friction Course Mix Design Methods Currently Used In The United States, Laura Kline May 2010

Comparision Of Open Graded Friction Course Mix Design Methods Currently Used In The United States, Laura Kline

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This research compares the open graded friction course (OGFC) mix design methods which are currently being used in the United States. OGFCs are a type of porous pavement that have been used in the United States since 1944, but has provided inconsistent and highly variable performance results. The design procedures for several agencies were obtained, and then compared for similarities. All of the design methods were then conducted to determine the optimum binder content. The optimum binder content (OBC) of a single aggregate gradation for each method was tested for properties and performance characteristics.
The design methods which are currently …

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Kinetic And Finite Element Modeling For Firing Brick, Daniel Mckinney May 2010

Kinetic And Finite Element Modeling For Firing Brick, Daniel Mckinney

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Kinetic modeling and simulation were used to optimize the firing cycle for brick. This was done to develop a tool for the brick industry to reduce fuel consumption and emissions during firing. A kinetic model was built using shrinkage data from dilatometer measurements and mass loss data from thermogravimetry measurements in order to predict the density as a function of temperature and time. The density of brick was related to the absorption coefficient (C/B), an ASTM standard which is related to the durability of the brick. The kinetic model was used to optimize the firing curve using a rate controlled …

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A Proposed Method To Identify Requirements Significant To Mass Reduction, James Mclellan May 2010

A Proposed Method To Identify Requirements Significant To Mass Reduction, James Mclellan

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Reducing the mass of engineering products holds the potential for significant benefits by reducing material costs, environmental impact, transportation costs, and in the case of vehicles, reducing fuel consumption. While there are many approaches for reducing mass, analyzing requirements has the greatest potential since requirements definition is the earliest phase of product development, where the most design freedom exists. This thesis proposes a requirement analysis method that identifies requirements that impact significant amounts of mass. The research hypothesis is: Engineering requirements can be represented and processed in a systematic manner and linked to physical components and systems, thus enabling mass …

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Comprehensive Analysis Of A Student-Centered Active-Learning Integrated Statics And Dynamics Course For Mechanical Engineers, Marisa Orr May 2010

Comprehensive Analysis Of A Student-Centered Active-Learning Integrated Statics And Dynamics Course For Mechanical Engineers, Marisa Orr

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The Student-Centered Active Learning in Undergraduate Programs (SCALE-UP) approach to instructional design was adapted with the goal of delivering more effective statics, dynamics and multivariate calculus instruction and integrated course curricula. Inquiry-based learning exercises were designed, incorporating material from statics and dynamics into multivariable calculus, and vice-versa, as well as integrating statics and dynamics into one course. Analysis included an exploration of student study habits, multiple measures of course effectiveness, and an examination of curricular effects. Challenges of implementation are also discussed.
Study habits of students in an integrated Statics and Dynamics course were assessed through a voluntary survey in …

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Responses Of Problematic Algae To Algaecide Exposures, West Bishop May 2010

Responses Of Problematic Algae To Algaecide Exposures, West Bishop

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Excessive growths of algae can cause significant disruption of critical water resource usages including: drinking, irrigation, recreation as well as be aesthetically displeasing. Water resource managers are often compelled to take action to mitigate these nuisance algal infestations. Algaecides can be efficient and effective management options to rapidly suppress algal blooms and restore water usages. However, laboratory and field data are required to accurately predict responses to an application as well as potential risks to non-target organisms. Laboratory experiments were used to measure the responses of problematic algae to algaecide exposures and evaluate the margin of safety to sensitive, non-target …

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A Lyapunov Based Approach To Energy Maximization In Renewable Energy Technologies, Erhun Iyasere May 2010

A Lyapunov Based Approach To Energy Maximization In Renewable Energy Technologies, Erhun Iyasere

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This dissertation describes the design and implementation of Lyapunov-based control strategies for the maximization of the power captured by renewable energy harnessing technologies such as (i) a variable speed, variable pitch wind turbine, (ii) a variable speed wind turbine coupled to a doubly fed induction generator, and (iii) a solar power generating system charging a constant voltage battery.
First, a torque control strategy is presented to maximize wind energy captured in variable speed, variable pitch wind turbines at low to medium wind speeds. The proposed strategy applies control torque to the wind turbine pitch and rotor subsystems to simultaneously control …

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Liquid-Liquid Equilibrium For Iodine-Hydroiodic Acid-Water Mixtures At Elevated Temperatures And Pressures For The Sulfur-Iodine Cycle, Sarah Mena May 2010

Liquid-Liquid Equilibrium For Iodine-Hydroiodic Acid-Water Mixtures At Elevated Temperatures And Pressures For The Sulfur-Iodine Cycle, Sarah Mena

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An alternative scenario to the overdependence on fossil fuels is the use of thermochemical cycles to split water into hydrogen and oxygen. The Sulfur-Iodine (SI) cycle, developed at General Atomics in the mid 1970s, is a leading candidate of international interest for the centralized production of hydrogen from nuclear and/or solar power. For a comprehensive assessment of the SI cycle, thermodynamic data for I2-HI-H2O mixtures at elevated temperatures and pressures have been identified as a basic research need.

The focus of this study was liquid-liquid equilibrium (LLE) measurements for the above system. To carry out the measurements, a continuous-flow apparatus …

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Women As Sustainability Leaders In Engineering: Evidence From Industry And Academia, Jennilee Harrison May 2010

Women As Sustainability Leaders In Engineering: Evidence From Industry And Academia, Jennilee Harrison

All Theses

Women are underrepresented in engineering education and practice, which limits the quality of the engineering workforce. One way to increase the participation of women in engineering is to emphasize subjects that appeal to them and emphasize skills at which they are especially adept. A subject that may fit this description is sustainability. The purpose of this research is to compare the percentage of women in selected sustainable engineering leadership positions to the percentage of women in general engineering leadership positions, to examine whether the subject of sustainability may help increase participation of women in engineering. Gender data was collected for …

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Osteoclast-Mediated Cell Therapy As An Attempt To Treat Elastin-Specific Vascular Calcification, Chartrisa Simpson May 2010

Osteoclast-Mediated Cell Therapy As An Attempt To Treat Elastin-Specific Vascular Calcification, Chartrisa Simpson

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Vascular calcification occurs during physiological aging and is clinically recognized as a major risk factor for myocardial infarction, systolic hypertension, heart failure and coronary insufficiency caused by loss of aortic recoil. Medial arterial calcification is an active remodeling process that involves the deposition of bone-specific matrix in close association with elastic fibers. Elastin, a major structural protein in the extracellular matrix of arterial walls, provides elastic recoil to the arteries. Increasing evidence suggests that vascular calcification share features with skeletal bone formation such as bone matrix deposition and bone resorption. Bone morphogenetic proteins and bone cells have been found in …

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Biodegradation And Bioremediation Of Hexachlorocyclohexane Isomers, Chlorinated Ethenes, Chlorinated Benzenes And Benzene, Vijaikrishnah Elango May 2010

Biodegradation And Bioremediation Of Hexachlorocyclohexane Isomers, Chlorinated Ethenes, Chlorinated Benzenes And Benzene, Vijaikrishnah Elango

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ABSTRACT
Groundwater at an industrial site is contaminated with γ -hexachlorocyclohexane (HCH) and α-HCH (i.e., lindane) (0.3-0.5 ppm). Other contaminants in the 1-15 ppm range include 1,2,4-trichlorobenezene (TCB), 1,2-dichlorobenzene (DCB), 1,3-DCB, 1,4-DCB, chlorobenzene (CB), benzene, trichloroethene (TCE) and cis-1,2-dichloroethene (cDCE). The aquifer consists of a shallow layer of soil over fractured dolomite, where most of the contaminant mass resides. The objective of this study was to compare 1) anaerobic reductive dechlorination of the polychlorinated contaminants, followed by aerobic biodegradation of the daughter products (mainly DCBs, CB, and benzene); and 2) aerobic biodegradation of α- and γ-HCH, TCB, DCBs, CB and …

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