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Full-Text Articles in Engineering

Optimizing The Mechanical Properties Of Partially Yttria Stabilized Zirconia With Alumina Additions, Ramanaganapathy Kandaswamy Dec 2010

Optimizing The Mechanical Properties Of Partially Yttria Stabilized Zirconia With Alumina Additions, Ramanaganapathy Kandaswamy

All Theses

Zirconia is one of the extensively studied solid oxide ceramics with respect to its use in various industrial applications like electrolyte in fuel cells, sensors, refractories and exhaust chamber in automobile industry. It can be found from the literature 1-4 that are contradictory results on the mechanical properties when alumina is added. There are several factors like microstructure, phase composition and method of processing that affects the mechanical properties of the material. The focus of this research is to examine how hardness, tensile strength and other properties varies with alumina content and deduce the optimal amount of alumina that is …


A Numerical And Experimental Study Of Differential Settling In Cohesive Sediment, Chad Heiliger Dec 2010

A Numerical And Experimental Study Of Differential Settling In Cohesive Sediment, Chad Heiliger

All Theses

Accurate sedimentation modeling has important applications in a number of fields. This includes modeling the accumulation of sediment in harbor channels and modeling the sedimentation and accumulation of particles in retention ponds in the still waters behind dams in order to calculate the trap efficiency. By accurately modeling sedimentation, engineering failures such as the 2008 TVA spill at the Kingston Fossil Plant could possibly be avoided. Three different numerical models comparing the settling rates of individual particles in quiescent waters were created to compare the change of settling velocity due to particle size distributions, change of local concentrations, and flocculation …


Mass And Assembly Time Reduction For Future Generation Automotive Vehicles Based On Existing Vehicle Model, Essam Namouz Dec 2010

Mass And Assembly Time Reduction For Future Generation Automotive Vehicles Based On Existing Vehicle Model, Essam Namouz

All Theses

This research presents method for evaluating the lightweightedness of a vehicle and an approach for vehicle assembly time savings potential developed through a case study. The Lazy Part Identification method for mass reduction specifically addresses those components whose primary purpose is to aid in manufacturing and assembly rather than to provide end-user function. Seven specific laziness indicators are described and illustrated: rigid-to-rigid connection, support for a flexible, non-moving part, positioning feature, duplicate geometry, fastener, bridging system, and material flow restriction. These indicators are used to evaluate individual vehicle components as part of a proposed method for identifying mass reduction potential. …


Determining The Global Maximum Biofuel Production Potential Without Conflicting With Food And Feed Consumption, Watcharapol Pumkaew Dec 2010

Determining The Global Maximum Biofuel Production Potential Without Conflicting With Food And Feed Consumption, Watcharapol Pumkaew

All Theses

This study tries to resolve the competition between food and biofuel by balancing the allocation between food and feed areas and biofuel areas for the entire world. The maximum energy production is calculated by determining the theoretical amount of energy that can be grown, once food and feed consumption is taken into account, based on the assumption that unprotected grass and woody lands and forest lands can be converted into cultivated lands. The total optimum land area for biofuel energy, 4,926.49 Mha, consists of corn, rapeseed, sugar beet, sugar cane, and grasses. When considering energy conversion efficiency, the maximum energy …


Molecular Physics Of Electrical Double Layers In Electrochemical Capacitors, Guang Feng Dec 2010

Molecular Physics Of Electrical Double Layers In Electrochemical Capacitors, Guang Feng

All Dissertations

At present, electrochemical capacitors (ECs) are emerging as a novel type of energy storage devices and have attracted remarkable attention, due to their key characteristics, such as high power density and excellent durability. However, the moderate energy density of ECs restricts their widespread deployment in everyday technology. To surmount this limitation, four strategies are adopted: (1) to reduce the total system mass, (2) to increase the specific surface area of electrodes, (3) to enhance normalized capacitance, and (4) to expand the range of potentials applied on electrodes. The implementation of these approaches critically relies on the fundamental understanding of physical …


Circuit Modules For Broadband Cmos Six-Port Systems, Chaojiang Li Dec 2010

Circuit Modules For Broadband Cmos Six-Port Systems, Chaojiang Li

All Dissertations

This dissertation investigates four circuit modules used in a CMOS integrated six-port measurement system. The first circuit module is a wideband power source generator, which can be implemented with a voltage controlled ring oscillator. The second circuit module is a low-power 0.5 GHz - 20.5 GHz power detector with an embedded amplifier and a wideband quasi T-coil matching network. The third circuit module is a six-port circuit, which can be implemented with distributed or lumped- lement techniques. The fourth circuit module is the phase sifter used as calibration loads. The theoretical analysis, circuit design, simulated or experimental verifications of each …


Comprehensive Thermal Modeling Of Power Split Hybrid Power-Train And Electronics, Abdel Mayyas Dec 2010

Comprehensive Thermal Modeling Of Power Split Hybrid Power-Train And Electronics, Abdel Mayyas

All Dissertations

Hybrid electric vehicle (HEV) uses both internal combustion engine (ICE) with an electric system. The combination of the electric power train with the ICE is intended to achieve both better fuel economies than the conventional vehicles and better performance. Several types of HEV exist with different layouts. Recent HEVs' make use of regenerative braking, which converts the vehicles' kinetic energy into electric energy instead of wasting it as heat as conventional brakes do. A hybrid-electric is more fuel efficient than ICE and has less environmental impact.
The new HEV with its new Key Characteristics and Configurations (i.e. Mechanical complexity, Multiple …


Sensitivity Analysis Of Uranium Speciation Modeling In Groundwater Systems With A Focus On Mobility, Andrew Scott Dec 2010

Sensitivity Analysis Of Uranium Speciation Modeling In Groundwater Systems With A Focus On Mobility, Andrew Scott

All Dissertations

Uranium is an important natural resource used in production of nuclear reactor fuel and nuclear weapons. The mining and processing of uranium has left a legacy of environmental contamination that remains to be addressed. There has been considerable interest in manipulating the oxidation state of uranium in order to put it into an environmentally immobile form. Uranium forms two stable oxidation states in nature, uranium (IV) being much less soluble than uranium (VI), and therefore the preferred state with regard to limiting the potential exposure of man. One of the tools used in evaluating potential effects of manipulating the natural …


A Meta-Analysis Of Human Factors Analysis And Classification System Causal Factors: Establishing Benchmarking Standards And Human Error Latent Failure Pathway Associations In Various Domains, Katherine Berry Dec 2010

A Meta-Analysis Of Human Factors Analysis And Classification System Causal Factors: Establishing Benchmarking Standards And Human Error Latent Failure Pathway Associations In Various Domains, Katherine Berry

All Dissertations

Many models of accident investigation have been created and have served as the basis for other tools and techniques. One of the most prominent techniques, Reason's Swiss Cheese Model (1990), is based on the idea of active and latent failures. Expanding on this idea, the Human Factors Analysis and Classification System (HFACS) was created with the idea to associate contributing factors and errors (Wiegmann & Shappell, 2003).
While HFACS has been frequently applied in the field of aviation in literature, other industry types are under-represented. Seventeen data sources encompassing various industry types were collected and included in this dissertation analysis. …


Modulated Properties Of Fully Absorbable Bicomponent Meshes, Shawn Peniston Dec 2010

Modulated Properties Of Fully Absorbable Bicomponent Meshes, Shawn Peniston

All Dissertations

Current meshes used for soft-tissue repair are mostly composed of single component, nonabsorbable yarn constructions, limiting the ability to modulate their properties. This situation has left the majority of soft tissue repair load-bearing applications to suffer distinctly from undesirable features associated, in part, with mesh inability to (1) possess short-term stiffness to facilitate tissue stability during the development of wound strength; (2) gradually transfer the perceived mechanical load as the wound builds mechanical integrity; and (3) provide compliance with load transfer to the remodeling and maturing mesh/tissue complex. The likelihood of long-term complications is reduced for fully absorbable systems with …


Order Picking And Storage Using Stackable Pallets In A Warehouse, Ahmed Hassan Aly Dec 2010

Order Picking And Storage Using Stackable Pallets In A Warehouse, Ahmed Hassan Aly

All Dissertations

Quarter Billion dollars could be saved annually by double stacking pallets. A forklift storing 100 double stacked pallets saves 2.5 working hours versus single pallets. More than one billion pallets and cases handled between Wal-Mart distribution centers according to BEA White Paper (2006) [1], assume only 500 million were stackable pallets. This translates to 12.5 million working hours. If a forklift driver earns $20 per hour, then $250 million can be saved.
Moreover, handling double stacked pallets takes up to 46 % of total time to pick and store. This is a significant element that was ignored in literature. All …


Novel Vascular Grafts Based On Polyphenol-Stabilized Acellular Tissue Scaffolds, Ting-Hsien Chuang Dec 2010

Novel Vascular Grafts Based On Polyphenol-Stabilized Acellular Tissue Scaffolds, Ting-Hsien Chuang

All Dissertations

The Cardiovascular diseases (CVDs) continue to be the leading cause of morbidity and mortality worldwide. The most common form of CVDs is occlusion of blood flow thus limiting blood supply to specific tissues or organs. Atherosclerosis is a leading cause of coronary heart disease and stroke, which were responsible for more than 25% of deaths in 2004.
The demand for vascular graft is huge. In United States alone, approximately 500,000 coronary artery bypass graft surgeries are performed annually. Synthetic polymers such as Dacron and ePTFE have been successfully applied in large diameter blood vessel prosthesis; however, for small diameter (inner …


Offshore Wind Power Integration Into The South Carolina Power System, Mountaga Fane Dec 2010

Offshore Wind Power Integration Into The South Carolina Power System, Mountaga Fane

All Theses

The steady state analysis of the impact of offshore wind on the South Carolina power transmission was conducted in three phases of incremental wind energy injection into the system using forecasted base power flow. The simulation of Phase I involved the generation capacity of 80 MW projected for 2014 in state water. The modeling Phases II and III, which will distribute the energy among neighboring utilities, involve a supplementary capacity of 1000 MW projected for 2020 and 2000 MW for 2030 in federal water. In addition to this steady state investigation, a contingency analysis was performed on the power system …


Design Decisions Under Risk And Uncertainty, Sravya Thoomu Dec 2010

Design Decisions Under Risk And Uncertainty, Sravya Thoomu

All Theses

In the contemporary world of engineering, engineers strive towards designing reliable and robust artifacts while considering and attempting to control manufacturing costs. In due course they have to deal with some sort of uncertainty. Many aspects of the design are the result of properties that are defined within some tolerances, of measurements that are appropriate, and of circumstances and environmental conditions that are out of their control. This uncertainty was typically handled by using factors of safety, and resulted in designs that may have been overly conservative. Therefore, understanding and handling the uncertainties is critical in improving the design, controlling …


Effect Of Ultrasonic Vibration On The Mass Transfer Coefficient In A Sieve Plate Scrubber, Dinora Monroy Melendez Dec 2010

Effect Of Ultrasonic Vibration On The Mass Transfer Coefficient In A Sieve Plate Scrubber, Dinora Monroy Melendez

All Theses

The air pollution technique of wet scrubbers for fumes, mists and suspended dusts as part of a polluted gas stream has been study as well as used for industries for many decades. The sieve tray is the simplest type of these scrubbers. A laboratory-scale single-stage, sieve tray countercurrent wet scrubber has been designed to study the effect of ultrasonic vibrations on the rate of mass transfer. A 20 kHz ultrasound frequency was chosen for a high performance cavitation to enhance the mass transport between the gas and liquid phases. Various perforation diameters and weir heights were employed in order to …


Determination Of Sorption Coefficients For Neptunium, Plutonium, Iodine, And Technetium In Engineered And Natural Systems Under Oxidizing And Reducing Conditions, Michael Lilley Dec 2010

Determination Of Sorption Coefficients For Neptunium, Plutonium, Iodine, And Technetium In Engineered And Natural Systems Under Oxidizing And Reducing Conditions, Michael Lilley

All Theses

Plutonium, neptunium, technetium, and iodine present appreciable risks at nuclear waste disposal sites around the world due to their potential mobility. Sorption of each of these radionuclides is profoundly influenced by oxidation/ reduction reactions. Therefore, the mobility of each radionuclide may be greatly influenced by redox conditions of the natural or engineered system. The primary focus of this study was to determine distribution coefficients (Kd) for each radionuclide for engineered concrete and saltstone systems with varying amounts of reducing slag (a cement additive to create a reducing environment), and for iodide/iodate in natural sediments. Saltstones are a mixture …


Modeling Greenhouse Gas Emissions From Conventional Wastewater Treatment Plants In South Carolina, Andrea Hicks Dec 2010

Modeling Greenhouse Gas Emissions From Conventional Wastewater Treatment Plants In South Carolina, Andrea Hicks

All Theses

Wastewater treatment is an essential part of life in the urbanized world. As global climate change becomes a more pressing issue, the greenhouse gas emissions created through wastewater treatment will become a more prominent concern. Tertiary treatment will likely be standard for wastewater treatment plants in the near future, and therefore must be included in a model of greenhouse gas emissions. Also, the geographic location of a WWTP will change the mix of power types (e.g., coal, nuclear, biomass) used to run the plant. Although GHG emissions from the waste sector are small compared to the emissions of the United …


On The Use Of Natural-Mode Basis Functions For Electromagnetic Analysis Of Arbitrary Conducting Surfaces, Joshua Lawrence Dec 2010

On The Use Of Natural-Mode Basis Functions For Electromagnetic Analysis Of Arbitrary Conducting Surfaces, Joshua Lawrence

All Theses

The natural modes defined in the singularity expansion method (SEM) are used as basis functions for the frequency- and time-domain current responses of arbitrary perfect electrically conducting (PEC) surfaces in this work. First, a method of determining the natural frequencies and corresponding modes which employs the electric field integral equation is presented. These quantities are then calculated for several geometries and the currents induced due to an incident plane wave in the frequency and time domains are approximated by a weighted sum of the natural modes. Additionally, the modal weights prescribed by SEM are compared to a set of weights …


Investigation Of Northeast Extreme Tee (Next) D Beam Bridges As An Alternative To Precast Hollow Core Bridges: An Exploration Of Appropriate Slab Design Forces, Daniel Deery Dec 2010

Investigation Of Northeast Extreme Tee (Next) D Beam Bridges As An Alternative To Precast Hollow Core Bridges: An Exploration Of Appropriate Slab Design Forces, Daniel Deery

All Theses

Adjacent precast, prestressed concrete beam bridges have become a popular solution throughout the country because deck forming can be eliminated and construction is rapid. In South Carolina, adjacent beam bridges primarily consist of flat slab or hollow core sections, and they are currently only used on secondary, low-volume, short-span bridges. Durability and load sharing issues stemming from cracking, however, have caused concern with the longevity of these bridge types. Thus, the South Carolina Department of Transportation (SCDOT) has sought an alternative to the flat slab for short span bridges that can be used on high volume roads without an overlay. …


Advanced Automotive Thermal Management - Operation Of An Electric Radiator Fan Array For Reduced Electric Power Consumption, Amit Jagarwal Dec 2010

Advanced Automotive Thermal Management - Operation Of An Electric Radiator Fan Array For Reduced Electric Power Consumption, Amit Jagarwal

All Theses

The depletion of fossil fuel reserves and the limited renewable energy resources have raised public awareness about the need to improve fuel efficiency in ground transportation vehicles. The internal combustion engine remains one of the primary industrial machines using gasoline or diesel fuel to produce mechanical work. In these engines, the cooling system performs the vital role of removing waste heat to ensure normal combustion processes in the cylinders. To accomplish this task, the radiator, the radiator fan(s), the thermostat valve, and the water pump operated by circulating cooling fluid through the engine block and rejecting heat to the atmosphere. …


Assessment And Analysis Of Emotional Intelligence In Engineering Students, Xiaodan Zhou Dec 2010

Assessment And Analysis Of Emotional Intelligence In Engineering Students, Xiaodan Zhou

All Theses

ABSTRACT
Current research on the importance and relevance of the relationship between emotional intelligence and work outcomes has continuously gained momentum since the publication of Daniel Goleman's best seller Emotional Intelligence: Why It Can Matter More Than IQ (Goleman, 1995). Professional expertise is no longer the only standard by which to evaluate graduates. 'Soft skills', like emotional intelligence are viewed as effective ways, to distinguish potential high-performance workers and those who will be 'no more than' a worker. This paper made an attempt to correlate emotional intelligence with academic performance of civil engineering students. The emotional capability of the students …


Correcting Liquefaction Resistance Of Partially Saturated Soil Using Compression Wave Velocity, Md Hossain Dec 2010

Correcting Liquefaction Resistance Of Partially Saturated Soil Using Compression Wave Velocity, Md Hossain

All Theses

Empirical relationships for correcting liquefaction resistance of partially saturated soil using longitudinal (P-) wave velocity (VP) and shear (S-) wave velocity (VS) are developed and evaluated in this thesis. The relationships are based on the laboratory test results for four different types of sands and one silt published by other investigators. The data used to develop the relationship with VP exhibit less scatter than the data used to develop the relationship with VP/VS. For this reason, the VP based relationship is recommended for correcting liquefaction resistance of partially saturated soil. …


Evaluation Of Utility Relocation Costs And Best Management Practices, Michael Reinke Dec 2010

Evaluation Of Utility Relocation Costs And Best Management Practices, Michael Reinke

All Theses

In recent years, the SCDOT has experienced a significant variation in estimated costs for the relocation of utilities on many projects. This has led to cost overruns and caused concerns for the district engineers responsible for the projects. Through meetings with SCDOT personnel and utility company representatives it was determined that a standardized cost estimate form combined with improved change order management and cost management strategies was needed. Recently submitted estimates were analyzed and rated by a panel on multiple criteria to generate a list of 'poor', 'good', and 'excellent' estimates. The 'excellent' estimates provided insight into the development of …


Analysis Of Alternative Manufacturing Processes For Lightweight Biw Designs, Using Analytical Hierarchy Process, Srinath Vijayakumar Dec 2010

Analysis Of Alternative Manufacturing Processes For Lightweight Biw Designs, Using Analytical Hierarchy Process, Srinath Vijayakumar

All Theses

The main objective of the analysis was to investigate the forming of Body in White (BIW) panels using alternative processes most suitable for replacing the conventional press working process in order to achieve a reduction in the total mass of the vehicle body structure. The selection of the alternatives was guided by multi criteria decision making tool, the Analytic Hierarchy Process (AHP). Here the alternatives were selected based on their relative importance to the different manufacturing attributes considered. The selected processes were applied to the manufacturing of different parts of BIW indicated in the BOM along with suggestion of the …


Analysis Of Part Consolidation Techniques For Automotive Body In White Panels Based On Advanced Sheet Metal Forming Technologies, Harish Thiruvengadam Dec 2010

Analysis Of Part Consolidation Techniques For Automotive Body In White Panels Based On Advanced Sheet Metal Forming Technologies, Harish Thiruvengadam

All Theses

The automotive industry is looking to move from mass production to mass customization in order to manufacture and sell a variety of products in different markets on a global scale. This requires a robust and cost effective manufacturing system which would help design new products in the shortest possible lead time. This thesis tries to investigate the current sheet metal forming process for body in white, identify the limitations and propose an alternative which would help the industry cut down product lead time and costs. Decision making tools are used to identify the technical requirements of a BIW manufacturing system …


Evaluation Of Tetrachloroethene Dechlorination Under Low Ph Conditions In Microcosms And Enrichment Cultures, Michael Hickey Dec 2010

Evaluation Of Tetrachloroethene Dechlorination Under Low Ph Conditions In Microcosms And Enrichment Cultures, Michael Hickey

All Theses

Chlorinated ethenes are among the most prevalent groundwater contaminants found at hazardous waste sites throughout the United States. Two such sites are the Statesville FCX OU3 Superfund Site in North Carolina and the C-area at the Savannah River Site (SRS) in Aiken, SC. Both sites are contaminated with two of the more common chlorinated ethenes; tetrachloroethene (PCE) and trichloroethene (TCE). Anaerobic biological reductive dechlorination is an increasingly common treatment option. There are two main concerns as to the feasibility of this approach. The first is if the microbes are present that are needed for carrying out complete reductive dechlorination of …


Characterization Of Anti-Proteolytic And Anti-Proliferative Activities Of Pentagalloylglucose; Its Potential Application As A Therapeutic Agent In Vascular Diseases, Chaitra Cheluvaraju Dec 2010

Characterization Of Anti-Proteolytic And Anti-Proliferative Activities Of Pentagalloylglucose; Its Potential Application As A Therapeutic Agent In Vascular Diseases, Chaitra Cheluvaraju

All Dissertations

Cardiovascular diseases are the leading causes of mortality in the United States and will cost around $500 billion this year alone. Elevated proteolytic activity, increased proliferation and migration of vascular smooth muscle cells are hallmarks of atherosclerosis, stenosis and aortic aneurysms. These diseases often manifest the transdifferentiation of vascular smooth muscle cells into osteoblast-like cells followed by deposition of hydroxyapatite–like mineral in the arterial walls.
Currently, there are no standard treatments available for vascular calcification or aneurysms. Atherosclerosis treatment options are limited to statins while balloon angioplasty and stenting – surgical procedures for stenosis, often end in restenosis. Therefore, we …


Characterization And Evaluation Of A Novel Tissue Engineered Aortic Heart Valve Construct, Mary Tedder Dec 2010

Characterization And Evaluation Of A Novel Tissue Engineered Aortic Heart Valve Construct, Mary Tedder

All Dissertations

Tissue engineering holds great promise for treatment of valvular diseases. Scaffolds for engineered heart valves must function immediately after implantation, but must also permit repopulation with autologous host cells and facilitate gradual remodeling.
Native aortic heart valves are composed of three layers, i.e. two strong external fibrous layers (ventricularis and fibrosa) separated by a central, highly hydrated spongiosa. The fibrous layers provide strength and resilience while the spongiosa layer facilitates shearing of the external layers. Our working hypothesis is that partially cross-linked collagen scaffolds that closely mimic the layered histo-architecture of the native valve would fulfill these requirements. To test …


An Investigation Of Metaheuristics Using Path- Relinking On The Quadratic Assignment Problem, Thashika Rupasinghe Dec 2010

An Investigation Of Metaheuristics Using Path- Relinking On The Quadratic Assignment Problem, Thashika Rupasinghe

All Dissertations

The Quadratic Assignment Problem (QAP) is a widely researched, yet complex, combinatorial optimization problem that is applicable in modeling many real-world problems. Specifically, many optimization problems are formulated as QAPs. To resolve QAPs, the recent trends have been to use metaheuristics rather than exact or heuristic methods, and many researchers have found that the use of hybrid metaheuristics is actually more effective. A newly proposed hybrid metaheuristic is path relinking (PR), which is used to generate solutions by combining two or more reference solutions. In this dissertation, we investigated these diversification and intensification mechanisms using QAP. To satisfy the extensive …


Packet Error Rate Predictive Model For Sensor Radios On Fast Rotating Structures, Lei Tang Dec 2010

Packet Error Rate Predictive Model For Sensor Radios On Fast Rotating Structures, Lei Tang

All Dissertations

Wireless sensing technologies have raised widespread interests in the applications for monitoring fast rotating or moving machinery structures in manufacturing environments. Over the past five years, a few wireless sensor systems have been implemented and proven to feasibly work under fast rotation conditions. However, few of these studies evaluated data transmission performance of the wireless communication systems. Although the manufacturing environments are known to be harsh for wireless communication, in many cases, an excellent data throughput is critical for such systems. Conventional statistical methods for studying wireless communication channels are not sufficient in this specific field.
This dissertation presents systematic …