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Full-Text Articles in Engineering

Determining Transverse Design Forces For A Next-D Bridge Using 3d Finite Element Modeling, Robert Funcik Dec 2011

Determining Transverse Design Forces For A Next-D Bridge Using 3d Finite Element Modeling, Robert Funcik

All Theses

This thesis looks into the use of 3D Finite Element Modeling to determine the transverse design forces for short-span bridges built using the Northeast Extreme Tee with integral deck (NEXT-D) beam. Models were built using either solid elements or shell elements to represent the bridge deck, and the results were compared. The stiffness of the shear keys were taken into account during the modeling process. Results were compared to the AASHTO strip width method for design bridge decks, and the results showed that the strip width method would not be adequate for the design of NEXT-D bridges, so specific live …


Using Gis-Based, Hitchcock Algorithm To Optimize Parking Allocations For Special Events, Wayne A. Sarasua, Prashant Malisetty, Mashrur Chowdhury Dec 2011

Using Gis-Based, Hitchcock Algorithm To Optimize Parking Allocations For Special Events, Wayne A. Sarasua, Prashant Malisetty, Mashrur Chowdhury

Publications

Clemson, a small college town in South Carolina, deals with a massive over-saturation of its transportation system during special events, especially during home football games, resulting in total system failure. This research has developed a methodology to optimize parking, using a Geographic Information System (GIS)-based transshipment algorithm, and it has produced great time savings compared with the individual, “manual” efforts of thousands of drivers attempting to find spaces where available. As such, this research constitutes an effective implementation of the Hitchcock Transportation Algorithm for solving a transshipment problem applied to parking lot distribution. Because the Hitchcock Algorithm considers the network …


Formation Of Halonitromethanes And Iodo-Trihalomethanes In Drinking Water Summary, Tanju Karanfil, Jia Hu, Darryl B. Jones, Jesse W. Addison, Hocheol Song Dec 2011

Formation Of Halonitromethanes And Iodo-Trihalomethanes In Drinking Water Summary, Tanju Karanfil, Jia Hu, Darryl B. Jones, Jesse W. Addison, Hocheol Song

Publications

The main purpose of this study was to examine the conditions and precursors involved in the formation of two emerging classes of disinfection by-products (DBPs), halonitromethanes (HNMs) and iodo-trihalomethanes (I-THMs), which are not currently regulated but have been observed in some drinking water systems.


Highly Conductive Carbon Nanotube Fibers For Biomedical Applications, Vijoya Sa Dec 2011

Highly Conductive Carbon Nanotube Fibers For Biomedical Applications, Vijoya Sa

All Dissertations

We developed a wet spinning process for the formation of polymeric fibers with high loading of single walled carbon nanotubes. The dissertation consists of five chapters. In the first chapter, the research goals were formulated and the art and technologies of fiber spinning from carbon nanotubes were critically analyzed. The next three chapters report the original results. Last chapter summarizes all the findings.
In the second chapter, we describe a surfactant based method of stabilization of carbon nanotube dispersions. The conditions of stability of nanotube dispersions in aqueous solutions of sodium dodecyl sulfate were analyzed. Using surface tension isotherms, the …


Evaluating The Use Of Functional Representations For Ideation In Conceptual Design, Benjamin Caldwell Dec 2011

Evaluating The Use Of Functional Representations For Ideation In Conceptual Design, Benjamin Caldwell

All Dissertations

Functional representations are often used in the conceptual stages of design because they encourage the designer to focus on the intended use and purpose of a system rather than the physical solution. Function models have been proposed by many researchers as a tool to expand the solution search space and guide concept generation, and many design tools have been created to support function-based design. These tools require designers to create function models of new or existing artifacts, but there is limited published research describing what types of functions should be included in a model or the appropriate level of abstraction …


Accelerating Pattern Recognition Algorithms On Parallel Computing Architectures, Kenneth Rice Dec 2011

Accelerating Pattern Recognition Algorithms On Parallel Computing Architectures, Kenneth Rice

All Dissertations

The move to more parallel computing architectures places more responsibility on the programmer to achieve greater performance. The programmer must now have a greater understanding of the underlying architecture and the inherent algorithmic parallelism. Using parallel computing architectures for exploiting algorithmic parallelism can be a complex task. This dissertation demonstrates various techniques for using parallel computing architectures to exploit algorithmic parallelism. Specifically, three pattern recognition (PR) approaches are examined for acceleration across multiple parallel computing architectures, namely field programmable gate arrays (FPGAs) and general purpose graphical processing units (GPGPUs).
Phase-only filter correlation for fingerprint identification was studied as the first …


An Investigation Of The Application Of Phase Change Materials In Practical Thermal Management Systems, David Ewing Dec 2011

An Investigation Of The Application Of Phase Change Materials In Practical Thermal Management Systems, David Ewing

All Dissertations

This work investigates the application of alternative cooling techniques to thermal management. In the first section, this work presents models and extensive simulation studies on an alternative cooling strategy based upon phase change materials (PCMs) for the thermal management system of a LED headlight assembly. These studies have shown that properly chosen PCMs, when suspended in metal foam matrices, increased the thermal conductivity of the PCM. The increased thermal conductivity can enhance the cooling characteristics of a practical thermal management system for a LED headlight system. To further enhance the advantages of using PCMs, nanoparticle enhanced fluids (nanofluids) are desirable …


Automated Digital Machining For Parallel Processors, Joshua Tarbutton Dec 2011

Automated Digital Machining For Parallel Processors, Joshua Tarbutton

All Dissertations

When a process engineer creates a tool path a number of fixed decisions are made that inevitably produce sub-optimal results. This is because it is impossible to process all of the tradeoffs before generating the tool path. The research presents a methodology to support a process engineers attempt to generate optimal tool paths by performing automated digital machining and analysis. This methodology automatically generates and evaluates tool paths based on parallel processing of digital part models and generalized cutting geometry. Digital part models are created by voxelizing STL files and the resulting digital part surfaces are obtained based on casting …


Optimization-Based Power Management Of Hybrid Power Systems With Applications In Advanced Hybrid Electric Vehicles And Wind Farms With Battery Storage, Hoseinali Borhan Dec 2011

Optimization-Based Power Management Of Hybrid Power Systems With Applications In Advanced Hybrid Electric Vehicles And Wind Farms With Battery Storage, Hoseinali Borhan

All Dissertations

Modern hybrid electric vehicles and many stationary renewable power generation systems combine multiple power generating and energy storage devices to achieve an overall system-level efficiency and flexibility which is higher than their individual components. The power or energy management control, ``brain' of these ``hybrid' systems, determines adaptively and based on the power demand the power split between multiple subsystems and plays a critical role in overall system-level efficiency. This dissertation proposes that a receding horizon optimal control (aka Model Predictive Control) approach can be a natural and systematic framework for formulating this type of power management controls. More importantly the …


Quantitative Analysis And Structural Characterization Of Carbonaceous Pitches, Sourabh Kulkarni Dec 2011

Quantitative Analysis And Structural Characterization Of Carbonaceous Pitches, Sourabh Kulkarni

All Dissertations

Both petroleum pitches and pitches derived from pure polycyclic aromatic hydrocarbons (PAHs) are oligomeric materials that can serve as precursors for a wide variety of advanced carbon materials. The goal of this study was the structural characterization and quantitative analysis of the dominant constituent oligomers and species present in these pitches.
A key requirement for such work is the ability to fractionate these complex mixtures into samples of narrow molecular weight distribution (mol wt; MWD) that can be used as standards. To this end, semicontinuous (or semibatch) dense-gas/supercritical extraction (DGE/SCE) was used to produce monomer, dimer, and trimer fractions of …


Development Of A Design Method To Reduce Change Propagation Effects, Prabhu Shankar Dec 2011

Development Of A Design Method To Reduce Change Propagation Effects, Prabhu Shankar

All Dissertations

ABSTRACT
This dissertation presents a design method to reduce engineering changes caused due to change propagation effect. The method helps designers to systematically plan a verification, validation, and test (VV&T) plan. The rationale behind such a method is founded on a well-accepted principle that a robust validation plan can reduce design changes. However, such method has not yet been developed in mechanical engineering domain, so a method from software engineering has been adopted and extended to address the limitations in the existing design evaluation tools.
Tools extensively used in industry, such as FMEA, and in academia have been reviewed to …


Modeling And Synthesis Of Functionalized Meta-Poly(Phenylene Ethynylene) Helical Structures, Ha Nguyen Dec 2011

Modeling And Synthesis Of Functionalized Meta-Poly(Phenylene Ethynylene) Helical Structures, Ha Nguyen

All Dissertations

The ability of meta-poly(phenylene ethynylene) (mPPE) materials to undergo random coil to helix conformational changes under select conditions affords many opportunities for their use in sensor, separation, catalysis, and bio-related applications. Thus, to advance the development of these materials, a modeling procedure based on replica exchange molecular dynamics (REMD) simulation was developed to reliably assess factors affecting the folding behaviors of functionalized mPPE variants in solution. A combinational modeling study of 20 functionalized mPPEs in five solvent conditions provided insight into how mPPE secondary structure is impacted by the complex relationship between mPPE functional groups and solvent moieties. Further, these …


Probabilistic Approaches To Stability And Deformation Problems In Braced Excavation, Zhe Luo Dec 2011

Probabilistic Approaches To Stability And Deformation Problems In Braced Excavation, Zhe Luo

All Dissertations

This dissertation is aimed at applying probabilistic approaches to evaluating the basal-heave stability and the excavation-induced wall and ground movements for serviceability assessment of excavation in clays. The focuses herein are the influence of spatial variability of soil parameters and small sample size on the results of the probabilistic analysis, and Bayesian updating of soil parameters using field observations in braced excavations.
Simplified approaches for reliability analysis of basal-heave in a braced excavation in clay considering the effect of spatial variability in random fields are presented. The proposed approaches employ the variance reduction technique (or more precisely, equivalent variance method) …


Fabrication Of Grooved Hollow Fiber Membrane For Nerve Regeneration: Process Modeling And Performance Evaluation, Jun Yin Dec 2011

Fabrication Of Grooved Hollow Fiber Membrane For Nerve Regeneration: Process Modeling And Performance Evaluation, Jun Yin

All Dissertations

Nerve injury is a general but intractable disease in traumatic injuries, leading to a significant reduction of functions in the nervous system. Extensive efforts are made on nerve injury rehabilitation. Since the appropriate connections between neurons and their targets are necessary, guiding axonal outgrowth is an essential step for neuron outgrowth in nervous system development, functioning, and regeneration. Besides the direct surgical nerve connection, an artificial means of guiding nerve regeneration called nerve conduits is widely applied in nerve injury rehabilitation. The main function of nerve conduits is to bridge the nerve gap, to help regenerating axons across damaged regions …


Spectral Engineering Of Optical Fiber Through Active Nanoparticle Doping, Tiffany Lindstrom-James Dec 2011

Spectral Engineering Of Optical Fiber Through Active Nanoparticle Doping, Tiffany Lindstrom-James

All Dissertations

The spectral engineering of optical fiber is a method of intentional doping of the core region in order to absorb/emit specific wavelengths of light therby providing enhanced performance over current fibers. Efforts here focused on developing an understanding of optically active nanoparticles based on alkaline earth fluorides that could be easily and homogeneously incorporated into the core of a silica based optical fiber preform and result in efficient and tailorable spectral emissions.
Doped and undoped calcium, strontium and barium fluoride nanoparticles were successfully synthesized and characterized for their physical, chemical, and optical behavior. Distinct spectroscopic differences as a result of …


Pitch-Based Activated Carbon Fibers: The Effect Of Precursor Composition On Pore Structure, Halil Tekinalp Dec 2011

Pitch-Based Activated Carbon Fibers: The Effect Of Precursor Composition On Pore Structure, Halil Tekinalp

All Dissertations

Although researchers have previously investigated the effect of precursor differences on the final properties of activated carbon fibers (ACFs), those precursors were not well-characterized. In particular, detailed information about their molecular composition and anisotropy was not available.
In this study, seven oligomeric fractions, each of well-defined composition and molecular weight (mol wt) distribution, were isolated from a commercially produced isotropic petroleum pitch (i.e., Marathon M–50) and used for the production of ACFs. Four of these precursors of varying oligomeric composition were fully isotropic and three contained different levels of mesophase, so that the effects of molecular composition and molecular order …


The Design Of A Haptic Device For Training And Evaluating Surgeon And Novice Laparoscopic Movement Skills, Ryan Bontreger Dec 2011

The Design Of A Haptic Device For Training And Evaluating Surgeon And Novice Laparoscopic Movement Skills, Ryan Bontreger

All Theses

As proper levels of force application are necessary to ensure patient safety, and training hours with an expert on live subjects are difficult, enhanced computer-based training is needed to teach the next generation of surgeons. Considering the role of touch in surgery, there is a need for a device capable of discerning the haptic ability of surgical trainees. This need is amplified by minimally invasive surgical techniques where a surgeon's sense of tissue properties comes not directly through their own hands but indirectly through the tools. A haptic device capable of producing a realistic range of forces and motions that …


Evaluation Of Bioaugmentation Strategies To Treat High Concentrations Of Chloroform And Carbon Tetrachloride, Han Wang Dec 2011

Evaluation Of Bioaugmentation Strategies To Treat High Concentrations Of Chloroform And Carbon Tetrachloride, Han Wang

All Theses

Halogenated methanes, including carbon tetrachloride (CT) and chloroform (CF), are significant groundwater contaminants. Options for bioremediation of high concentrations are limited. Previous studies have shown that an enrichment culture (designated DHM-1) that grows on corn syrup has the potential for use in bioaugmentation. DHM-1 cometabolically biotransforms high concentrations of CT and CF to nontoxic end products (mainly CO, CO2, and organic acids) in the presence of vitamin B12 (approximately 3% of chlorinated methanes on a molar basis). Sulfide is also required by this culture to function properly. However, insufficient data are available on its performance under field conditions. Also, it …


Robust Design And Monitoring Tools For Sustainable And Resilient Structural Design And Infrastructure Management, Sarah Dalton Dec 2011

Robust Design And Monitoring Tools For Sustainable And Resilient Structural Design And Infrastructure Management, Sarah Dalton

All Theses

Structural systems are subject to inherent uncertainties due to the variability in many hard-to-control `noise factors' that include but are not limited to external loads, material properties, and construction workmanship. Two design methodologies have been widely accepted in the practicing engineering realm to manage the variability associated with operational structures: Allowable Stress Design (ASD) and Load and Resistance Factor Design (LRFD). These traditional approaches explicitly recognize the presence of uncertainty; however, they do not take robustness against this uncertainty into consideration. Overlooking this robustness against uncertainty in the structural design process has two drawbacks. First, the design may not satisfy …


Fault-Tree Model For Bridge Collapse Risk Analysis, Caitlyn Davis-Mcdaniel Dec 2011

Fault-Tree Model For Bridge Collapse Risk Analysis, Caitlyn Davis-Mcdaniel

All Theses

Bridges are vital components of the United States surface transportation infrastructure and, moreover, support the growth of our nation's economy. However, over the past few decades the design capacity and service condition of many bridges in the U.S. has been challenged. Numerous incidents of bridge collapse call for an urgent need to develop a systematic method of assessing the failure risks and identifying the initiating events that can lead to a bridge collapse. This thesis presents a process of bridge failure risk analysis through fault-tree modeling and identification of specific countermeasures, to minimize failure risk, related to structural health monitoring …


The Integration Of Building Information Modeling (Bim) Into Civil Engineering Curricula, Jason Cooksey Dec 2011

The Integration Of Building Information Modeling (Bim) Into Civil Engineering Curricula, Jason Cooksey

All Theses

Building Information Modeling (BIM) is an emerging technology used in the Architecture/Engineering/Construction (AEC) industry. The proliferation of BIM usage across the industry has been swift and prolific. Academia has lagged behind the adoption rate of the industry by not producing enough students with BIM exposure. Thus, the question is whether civil engineering curricula should provide an understanding of BIM technology to students entering the design and construction profession. The immediate objective of this research is to determine if it is important to provide exposure of BIM to undergraduate or graduate students in the civil engineering curricula and if so to …


Fabrication And Characterization Of Multi-Functional Non-Spherical Particles Via Mechanical Deformation, Venkata Shilpa Varahagiri Dec 2011

Fabrication And Characterization Of Multi-Functional Non-Spherical Particles Via Mechanical Deformation, Venkata Shilpa Varahagiri

All Theses

Nanoparticles bridge the gap between bulk materials and molecules. They possess exciting but contrasting mechanical, chemical, magnetic and optical properties when compared to their bulk counterparts due to their shape and size. When the size of noble metal nanoparticles is reduced to less than the wavelength of light, the particles intensely absorb and scatter light at wavelengths that depend on the particle size, shape, and local dielectric environment due to Localized Surface Plasmon Resonance (LSPR) modes. Recently, plasmonic particles have been used in a wide variety of sensor and optical device applications including immunoassays and surface enhanced Raman spectroscopy substrates. …


Printing Carbon Nanotube Based Supercapacitors For Packaging, Alexandra Hartman Dec 2011

Printing Carbon Nanotube Based Supercapacitors For Packaging, Alexandra Hartman

All Theses

Living in a world full of portable electronics, there is great need for energy storage devices. Currently, limitations for storage involve power inefficiencies as well as bulkiness. This is why printable charge storage devices that display good electrochemical performance are needed. It is for this reason that research into the production and packaging of carbon nanotube based super capacitors was carried out.
A super capacitor can be built by using high surface area multi-walled carbon nanotubes suspended in an ionic liquid. The two active electrodes are made from a combination of the multi-walled carbon nanotubes and an ionic liquid, ground …


The Effects Of Solvent Mixture On The Thermal And Mechanical Properties Of Solvent Cast Poly-Lactic Acid (Pla) Film, Jeremy Hughes Dec 2011

The Effects Of Solvent Mixture On The Thermal And Mechanical Properties Of Solvent Cast Poly-Lactic Acid (Pla) Film, Jeremy Hughes

All Theses

CH 1 ABSTRACT
The objective of this study was to investigate the effects of various solvents on the crystallinity and thermal expansion stability of PLA film. Three different PLA films were produced by the solvent casting technique; PLA in chloroform (PLA-C), PLA in methylene chloride (PLA-M), and PLA in methylene chloride: acetonitrile = 50: 50 (PLA-MA). The PLA-MA had higher % crystallinity, 46.15, than the PLA-C, 24.03, and the PLA-M, 14.25. With this increase in crystallinity, the PLA-MA had improved thermal expansion stability as shown by very low accumulated dimensional changes at 20-100 ¡C. Wide angle x-ray diffraction identified multiple …


Effect Of Selected Phase Change Materials Concentration And Manufacturing Process On The Properties Of Plaster Mixture Systems, Rong Cui Dec 2011

Effect Of Selected Phase Change Materials Concentration And Manufacturing Process On The Properties Of Plaster Mixture Systems, Rong Cui

All Theses

Phase change materials (PCM) are generally used in building construction materials for their ability to absorb and release large amounts of energy when their phase change happens at their specific melting temperature. This results in a significant increase in thermal mass of the building, a reduction in temperature fluctuations and therefore a reduction in heating and cooling loads. However, in order to properly select a PCM and optimize its integration in a specific building, the properties of building construction materials enhanced with PCM must be known. This research focuses on studying the effects of the concentration of a micro-encapsulated PCM …


Chlorine Absorption Utilizing Caustic Sodium Sulfite, Henry Mcdonald Dec 2011

Chlorine Absorption Utilizing Caustic Sodium Sulfite, Henry Mcdonald

All Theses

A scrubber was required to abate a waste stream containing chlorine gas created in the electrolytic dissolution step of the aqueous polishing process at the Mixed Oxides Fuel Fabrication Facility at Savannah River Site, South Carolina. A method of absorption that utilized caustic sodium sulfite as the scrubbing agent was studied for implementation in the process. This method was found to be highly efficient with respect to process requirements, and it was also found to provide enhanced performance over the more conventional method of chlorine scrubbing which uses only aqueous sodium hydroxide as a reagent. Sulfite provides an additional advantage …


Parallel Implementation Of The Singular Value Decomposition Using Opencl, Bhushan Rayrikar Dec 2011

Parallel Implementation Of The Singular Value Decomposition Using Opencl, Bhushan Rayrikar

All Theses

General-Purpose Graphics Processing Units (GPGPUs) have massively parallel computational capabilities. Low cost and ease of programming make them a popular choice over other parallel architectures such as large clusters and accelerators such as Field-Programmable Gate Arrays (FPGAs). Mature programming frameworks for GPGPUs, such as CUDA from Nvidia and OpenCL from the Khronos Group, reduce the learning curve and development time for programming GPGPU architectures. OpenCL, a relatively new industry standard for parallel computing makes it possible to write a single program for heterogeneous platforms that is portable across multiple platforms including GPGPUs and multi-core processors with minimal coding modifications.
GPGPU …


Modeling Impacts Of Foothills Parkway Construction On Stream Water Quality Using Real-Time Remote Monitoring, Clark Chewning Dec 2011

Modeling Impacts Of Foothills Parkway Construction On Stream Water Quality Using Real-Time Remote Monitoring, Clark Chewning

All Theses

ABSTRACT
The need to monitor surface water quality has been increasingly recognized in recent years in environmental and natural resource management. The advent of real-time remote monitoring technologies has accelerated and enhanced this process. Field observations of water quality data are able to be conducted and analyzed in ways that were previously unavailable.
The objectives of this research were to deploy and test a real-time remote monitoring system for three small watersheds (Hembree, Dunn, and Rudd Hollows) in the Great Smoky Mountains. The watersheds ranged in size from 12 to 19 ha. Real-time remote monitoring stations were established in three …


A Methodology For Estimating And Comparing The Lifecycles Of High-Build And Conventional Waterborne Pavement Markings On Primary And Secondary Roads In South Carolina, Joseph Robertson Dec 2011

A Methodology For Estimating And Comparing The Lifecycles Of High-Build And Conventional Waterborne Pavement Markings On Primary And Secondary Roads In South Carolina, Joseph Robertson

All Theses

Highway pavement markings constitute a vital component of roadway transportation systems and provide crucial visual cues for the basic driver task of following the road. In 2008, the South Carolina Department of Transportation (SCDOT) initiated a multi-year study to evaluate pavement markings on non-interstate primary and secondary roads in South Carolina. This thesis discusses development of a methodology for estimating and comparing the lifecycles of high-build and conventional waterborne pavement markings based on retroreflectivity levels. The methodology was developed using nearly 3 years of field data from 66 sites throughout South Carolina. This thesis provides an overview of data collection …


New Analytical Bounds On The Probability Of Code-Word Error For Convolution Codes With Viterbi Decoding, Shweta Tomar Dec 2011

New Analytical Bounds On The Probability Of Code-Word Error For Convolution Codes With Viterbi Decoding, Shweta Tomar

All Theses

New analytical bounds are developed for the probability of code-word error in a communication system with convolutional coding and soft-decision Viterbi decoding. The bounds are applicable to communications in channels with asynchronous interferers which are modeled as independent, partial-time white Gaussian interference sources. This model is often used in simulations to reflect the circumstances encountered in many packet radio communication networks. The new results include both purely analytical bounds and offline-simulation-aided bounds that permit implementation of accurate communication-link models with much lower online computational and storage requirements than are required with traditional Monte Carlo simulations of link performance. They significantly …