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Clemson University

2012

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Full-Text Articles in Engineering

Induced Elastic Matrix Synthesis Within 3-Dimensional Collagen Constructs, Lavanya Venkataraman Dec 2012

Induced Elastic Matrix Synthesis Within 3-Dimensional Collagen Constructs, Lavanya Venkataraman

All Dissertations

Elastin, a primary component of elastic arteries, maintains structural stability of the cyclically recoiling artery, and critically regulates vascular cell behavior. Accelerated degradation of elastic matrix, such as that seen in vascular pathologies like abdominal aortic aneurysms (AAA), can therefore severely compromise vessel homeostasis. Tissue engineering and in-situ matrix repair strategies evaluated so far are primarily limited in inducing adult vascular cells to replicate the complex elastic matrix assembly process, and restore lost matrix integrity. Previously, our lab established the elastogenic benefits of concurrent delivery of TGF-β1 and HA-oligomers (together termed elastogenic factors, EFs), within 2D cultures of rat aortic …


Managing Elective And Non-Elective Case Assignments For An Operating Room Suite, Narges Hosseini Dec 2012

Managing Elective And Non-Elective Case Assignments For An Operating Room Suite, Narges Hosseini

All Dissertations

The success of operating room management depends on all levels of decision making, from strategic to tactical and operational decisions. One key decision in systems with block booking is to assign sufficient amount of block time to surgeons and surgery groups. While the typical method of block assignment identifies the share of surgery groups from OR times based on average of past usage, this method does not count for the difference between cost of under and overtime. One of the goals of this research is to develop a decision framework for block assignment. This work is presented in chapter two. …


Photo-Thermal Processing Of Semiconductor Fibers And Thin Films, Nishant Gupta Dec 2012

Photo-Thermal Processing Of Semiconductor Fibers And Thin Films, Nishant Gupta

All Dissertations

Furnace processing and rapid thermal processing (RTP) have been an integral part of several processing steps in semiconductor manufacturing. The performance of RTP techniques can be improved many times by exploiting quantum photo-effects of UV and vacuum ultraviolet (VUV) photons in thermal processing and this technique is known as rapid photo-thermal processing (RPP). As compared to furnace processing and RTP, RPP provides higher diffusion coefficient, lower stress and lower microscopic defects. In this work, a custom designed automated photo assisted processing system was built from individual parts and an incoherent light source. This photo-assisted processing system is used to anneal …


Supply Chain Network Design: Risk-Averse Vs. Risk-Neutral Decision Making, Alireza Madadi Dec 2012

Supply Chain Network Design: Risk-Averse Vs. Risk-Neutral Decision Making, Alireza Madadi

All Dissertations

Recent events, such as the Heparin tragedy, highlight the necessity for designers and planners of supply chain networks to consider the risk of disruptions in spite of their low probability of occurrence. One effective way to hedge against supply chain network disruptions is to have a robustly designed supply chain network. This involves strategic decisions, such as choosing which markets to serve, which suppliers to source from, the location of plants, the types of facilities to use, and tactical decisions, such as production and capacity allocation. In this dissertation, we focus on models for designing supply chain networks that are …


Develop Novel Frap Techniques For Determining Anisotropic Solute Diffusion In Cartilaginous Tissues, Changcheng Shi Dec 2012

Develop Novel Frap Techniques For Determining Anisotropic Solute Diffusion In Cartilaginous Tissues, Changcheng Shi

All Dissertations

Cartilaginous tissue is a connective tissue composed of specialized cells (e.g., chondrocytes and fibroblasts) that produce a large amount of extracellular matrix (ECM), which is comprised mostly of collagen fibers, abundant ground substance rich in proteoglycan, and elastic fibers. It is characterized by its avascular structures within the tissue, implying that nutrition for normal tissue cells, for maintaining a healthy ECM, is mainly supplied through diffusion from nearby vascularized tissues and synovial fluid. Poor nutritional supply to the cartilaginous tissue is believed to be an important factor leading to tissue degeneration. Moreover, due to the complex collagen fiber structures, the …


Application Of Carbon Dioxide Towards The Development Of Smart Materials, Green Reaction Schemes And Metallic Nanoparticle Synthesis, Fiaz Mohammed Dec 2012

Application Of Carbon Dioxide Towards The Development Of Smart Materials, Green Reaction Schemes And Metallic Nanoparticle Synthesis, Fiaz Mohammed

All Dissertations

Global carbon dioxide (CO2) emissions have steadily risen over the last 50 years, with 34 billion tons of CO2 released in 2009 alone. Its potential as a greenhouse gas has negatively affected of our lives and environment by the resulting ocean acidification and climate change. To mitigate atmospheric CO2, various strategies have been implemented for CO2 separation, capture, storage and use as a chemical feedstock. The use of CO2 in various chemical industries is attractive as its non-flammable, non-toxic, and relatively inert properties have made it an inherently safer alternative to traditional organic …


Environmental And Biological Applications And Implications Of Soft And Condensed Nanomaterials, Pengyu Chen Dec 2012

Environmental And Biological Applications And Implications Of Soft And Condensed Nanomaterials, Pengyu Chen

All Dissertations

Recent innovations and growth of nanotechnology have spurred exciting technological and commercial developments of nanomaterails. Their appealing physical and physicochemical properties offer great opportunities in biological and environmental applications, while in the meantime may compromise human health and environmental sustainability through either unintentional exposure or intentional discharge.
Accordingly, this dissertation exploits the physicochemical behavior of soft dendritic polymers for environmental remediation and condensed nano ZnO tetrapods for biological sensing (Chapter two-four), and further delineate the environmental implications of such nanomaterials using algae- the major constituent of the aquatic food chain-as a model system (Chapter five).
This dissertation is presented as …


Development Of Feature Recognition Algorithm For Automated Identification Of Duplicate Geometries In Cad Models, Aravind Shanthakumar Dec 2012

Development Of Feature Recognition Algorithm For Automated Identification Of Duplicate Geometries In Cad Models, Aravind Shanthakumar

All Theses

This research presents a feature recognition algorithm for the automated identification of duplicate geometries in the CAD assembly. The duplicate geometry is one of the seven indicators of the lazy parts mass reduction method. The lazy parts method is a light weight engineering method that is used for analyzing parts with the mass reduction potential. The duplicate geometry is defined as any geometries lying equal to or within the threshold distance with the user-defined orientation between them and have the percentage similarity that is equal to or greater than the threshold value. The feature recognition system developed in this research …


Characterization And Restoration Of Historic Rosendale Cement Mortars For The Purpose Of Restoration, Stephanie Hart Dec 2012

Characterization And Restoration Of Historic Rosendale Cement Mortars For The Purpose Of Restoration, Stephanie Hart

All Theses

Mortar was a very common building material in today's historic sites. Before Portland cement was manufactured at a global level, Rosendale cement was commonly used in these mortars. Over time, these mortars in historic sites have begun to break down and wear away. With Rosendale cement in production again, measures can be taken to restore and repair the historic mortars. However, little testing has been done to establish durability of modern Rosendale cement mortars. This presentation highlights the common mix techniques used at the time, and undergoes experiments to establish general properties and predict future durability. Six different mortar mixes …


Analysis And Evaluation Of Existing And Novel Turbulent Dynamic Pressure Based Methods For Measuring Bridge Pier And Abutment Scour, Murray Fisher Dec 2012

Analysis And Evaluation Of Existing And Novel Turbulent Dynamic Pressure Based Methods For Measuring Bridge Pier And Abutment Scour, Murray Fisher

All Dissertations

Scour is one of the most significant threats to bridge infrastructure and is the leading cause of failure within the United States. Given this risk to the nation’s transportation infrastructure, it is necessary to understand the development of scour holes around bridge piers and abutments. This can be achieved with scour monitoring, a Federal Highway Administration approved scour countermeasure. As the monitoring techniques available range from simple devices that rest on or in the channel bed to advanced scanning systems that provide a bed contour profile, a concise study of the state of the art in real time scour measurement …


Towards Trustworthy, Efficient And Scalable Distributed Wireless Systems, Ze Li Dec 2012

Towards Trustworthy, Efficient And Scalable Distributed Wireless Systems, Ze Li

All Dissertations

Advances in wireless technologies have enabled distributed mobile devices to connect with each other to form distributed wireless systems. Due to the absence of infrastructure, distributed wireless systems require node cooperation in multi-hop routing. However, the openness and decentralized nature of distributed wireless systems where each node labors under a resource constraint introduces three challenges: (1) cooperation incentives that effectively encourage nodes to offer services and thwart the intentions of selfish and malicious nodes, (2) cooperation incentives that are efficient to deploy, use and maintain, and (3) routing to efficiently deliver messages with less overhead and lower delay. While most …


The Effects Of Low Dose Ionizing Radiation Exposure On The Metabolic And Mechanical Properties Of Articular Cartilage, Carl Lindburg Dec 2012

The Effects Of Low Dose Ionizing Radiation Exposure On The Metabolic And Mechanical Properties Of Articular Cartilage, Carl Lindburg

All Theses

Radiation therapy is necessary treatment for many cancer patients due to its non-surgical, yet aggressive and efficacious properties. In fact, over 50% of patients with cancer will undergo some form of radiotherapy during the course of their treatment. While the biological response to ionizing radiation has been examined over the years and many adverse effects have been identified, the effects of radiation on mature cartilage and musculoskeletal tissues are not well understood. Bone, once thought to be a tissue relatively resistant to radiation, has recently been shown to have osteoporosis-like bone atrophy after exposure to low doses (2 Gy) of …


Development Of A Two-Dimensional Model Of A Pneumatic Tire, Timothy Lewis Dec 2012

Development Of A Two-Dimensional Model Of A Pneumatic Tire, Timothy Lewis

All Theses

The pneumatic tire has been studied extensively since its invention in 1888. With the advent of high-powered computers and the use of the finite element method, the understanding of the tire's complex non-linear behavior has grown tremendously. However, one weakness of finite element models is that parameter studies are difficult and time consuming to perform. In contrast, an analytical model can quickly and easily perform extensive parameter studies. To the knowledge of the author, all existing analytical models of the tire make assumptions concerning the tire's behavior and construction that while useful for obtaining some of the first-order characteristics, are …


Evaluation Of Rubber Modified Porous Asphalt Mixtures, Kimberly Lyons Dec 2012

Evaluation Of Rubber Modified Porous Asphalt Mixtures, Kimberly Lyons

All Theses

A porous pavement is a type of sustainable pavement that allows stormwater to infiltrate through the pavement into the natural soil bed. Rubber modified binder is the combination of regular asphalt binder mixed with ground crumb rubber, which is derived from used rubber tires by shredding or grinding the tires into small fragments. This research investigated the effects of rubber modified binder on the performance properties of porous asphalt mixtures, which include draindown, porosity, permeability, abrasion resistance, moisture susceptibility, and rutting resistance.
The addition of cellulose fibers has been used to increase the optimum binder content of porous asphalt mix …


Network Target Coordination For Design Optimization Of Decomposed Systems, Wenshan Wang Dec 2012

Network Target Coordination For Design Optimization Of Decomposed Systems, Wenshan Wang

All Dissertations

A complex engineered system is often decomposed into a number of different subsystems that interact on one another and together produce results not obtainable by the subsystems alone. Effective coordination of the interdependencies shared among these subsystems is critical to fulfill the stakeholder expectations and technical requirements of the original system. The past research has shown that various coordination methods obtain different solution accuracies and exhibit different computational efficiencies when solving a decomposed system. Addressing these coordination decisions may lead to improved complex system design. This dissertation studies coordination methods through two types of decomposition structures, hierarchical, and nonhierarchical.
For …


Assessment Of Fidelity To Data And Robustness To Uncertainty To Assure Credible Predictions In The Modeling Of Wind Turbine Blades, Kendra Van Buren Dec 2012

Assessment Of Fidelity To Data And Robustness To Uncertainty To Assure Credible Predictions In The Modeling Of Wind Turbine Blades, Kendra Van Buren

All Dissertations

In the field of wind energy, modeling and simulation techniques provide an efficient and economical alternative to experimentation for studying the behavior of wind turbines. Numerical models however are approximations of reality, thusly making it crucial to evaluate various sources of uncertainties that influence the model predictions. Credibility of a numerical model rests on the model's ability to replicate existing experimental data, widely known as fidelity-to-data. This dissertation advocates that fidelity-to-data, while necessary, is insufficient to claim credibility of a numerical model. Herein, the objective is to develop numerical models that not only provide agreement to experimental data, but also …


Phoneme Weighting And Energy-Based Weighting For Speaker Recognition, Eric Fang Dec 2012

Phoneme Weighting And Energy-Based Weighting For Speaker Recognition, Eric Fang

All Dissertations

This dissertation focuses on determining specific vowel phonemes which work best for speaker identification and speaker verification, and also developing new algorithms to improve speaker identification accuracy. Results from the first part of our research indicate that the vowels /i/, /E/ and /u/ were the ones having the highest recognition scores for both the Gaussian mixture model (GMM) and vector quantization (VQ) methods (at most one classification error). For VQ, /i/, /I/, /e/, /E/ and /@/ had no classification errors. Persons speaking /E/, /o/ and /u/ have been verified well by both GMM and VQ methods in our experiments. For …


Novel Electron Shuttling Compounds, Ramasubramanian Neeraja Dec 2012

Novel Electron Shuttling Compounds, Ramasubramanian Neeraja

All Theses

Electron mediator's usage in remediation technologies might be an excellent alternative to increase the rate of transformation of various contaminants such as nitroamine, polyhalogenated compounds and many others. Employing electron shuttles open up different pathways for the contaminant transformation and the reaction goes to completion at a much faster rate. Anthraquinone-2,6-disulfonate (AQDS) has been known to be a model electron shuttle with good shuttling capacity followed by humic acids. But the necessity for identifying electron shuttles suitable for field applications is important. As remediation technologies will command application of the shuttles on a large scale, tracing shuttles which are cheap, …


Product Display Versus Graphical Representation On Packaging, Joshua Galvarino Dec 2012

Product Display Versus Graphical Representation On Packaging, Joshua Galvarino

All Theses

ABSTRACT
Previous research conducted (Hurley, et al., 2012) concerning physical and graphical product visibility from the primary display panel (PDP) is limited to one product category. This research expands previous peer-reviewed research, which indicates that there is a significant difference between consumer preferences of graphical display vs. physical product display on packaging.
The shelf presence of packages showing actual product visibility versus packages showing only a graphical representation of the product was evaluated. Both shopping results and quantitative data using eye-tracking technology were collected and cross-referenced with a qualitative, post-experiment survey.
Specifically, variables of packaging within pasta, snacks, prepared frozen …


3d Reconstruction For Post-Disaster Analysis Of Civil Infrastructure, Joshua Caron Dec 2012

3d Reconstruction For Post-Disaster Analysis Of Civil Infrastructure, Joshua Caron

All Theses

Following a natural disaster, there is a need to rapidly assess the safety of civil infrastructure. This job is typically undertaken by local governments with the help of volunteer civil engineers with structural expertise, as well as organizations such as Cal EMA and ASCE. However, the inspection process is labor-intensive and a bit tedious, and results are prone to error as they tend to rely on the individual expertise of the inspectors. 3D reconstruction stands to become a useful tool in the safety evaluation process, as well as providing valuable opportunities for forensic engineering. This research explores the application of …


Bioswellable Amphiphilic Copolymers, David Ingram Dec 2012

Bioswellable Amphiphilic Copolymers, David Ingram

All Theses

The suture is one of the most commonly used medical devices, consisting of a fiber, a surgical needle and the packaging in which it is stored. The fiber itself remains after implantation for a defined time and is responsible for the approximation of the wound during the healing process. The needle merely serves to aid in insertion, and preferably has a diameter larger than the diameter of the fiber .
The 1970's marked the birth of a new family of fibrous materials for the approximation of wounds: synthetic absorbable sutures. This family has the ability to provide wound support during …


Investigation Of Auxiliary Winding Harmonic Resonance Phenomena In Single Phase Induction Motors, Gaurav Singh Dec 2012

Investigation Of Auxiliary Winding Harmonic Resonance Phenomena In Single Phase Induction Motors, Gaurav Singh

All Theses

In recent years, the proliferation of single phase power electronics based loads has given rise to a number of power quality issues in the power grid. Harmonics in voltage and current waveforms are one of the biggest problems in this family of power quality issues. Until some years back, power system utilities did not consider harmonics due to small single phase loads to be a big problem. In fact, only large loads were considered as potential hotspots for power quality problems. However, the advent of compact fluorescent lamps (CFLs), personal computers and consumer electronic devices, which utilize rectifier front ends, …


Updated Force Model For Milling Nickel-Based Superalloys, Andrew Henderson Dec 2012

Updated Force Model For Milling Nickel-Based Superalloys, Andrew Henderson

All Dissertations

Nickel-based superalloys are commonly used in applications which require high strength and resistance to creep and oxidation in extreme conditions. All nickel-based superalloys are considered difficult to machine; however, cast gamma-prime-strengthened nickel-based superalloys are more difficult to machine than common nickel-based superalloys. Machining comprises a significant portion of manufacturing processes and with advancements in technology and material properties, the methods and models used must be adapted in order to keep pace.
In this research, correlations are made, using fundamental principles, between measurements made with on-machine touch probes and the cutting tool's wear state, those correlations are used in an adaptive …


Integrated Production And Distribution Problem With Single Perishable Product, Wennian Li Dec 2012

Integrated Production And Distribution Problem With Single Perishable Product, Wennian Li

All Dissertations

This dissertation investigated the extension of the Integrated Production and Distribution Scheduling Problem (IPDSPP) using a variety of perishable products, applying the JIP principle and make-to-order strategy to integrate the production and distribution schedules. A single perishable product with a constant lifetime after production was used in the model discussed here. The objective of the problem was to find the solution that results in minimal system total transportation costs while satisfying customer demand within a fixed time horizon. In the solution, the fleet size, vehicle route and distribution schedule, plant production batch size and schedule were determined simultaneously. This research …


The Control Of Nitrogenous And Carbonaceous Disinfection Byproduct Precursors With Magnetic Ion Exchange, Xiaojie Gan Dec 2012

The Control Of Nitrogenous And Carbonaceous Disinfection Byproduct Precursors With Magnetic Ion Exchange, Xiaojie Gan

All Theses

The objective of this study was to examine the potential of the magnetic ion exchange (MIEX®) process to remove nitrogenous disinfection byproduct (N-DBP) precursors while minimizing carbonaceous DBP (C-DBP) precursors in different water matrices. In the first phase of the study, the MIEX® process was tested in raw dinking waters and waters impacted effluent from wastewater treatment plant. Samples were collected from several drinking water/wastewater treatment plants in South Carolina. The effluent impacted source waters were prepared by mixing treated wastewater effluents with a drinking water. For all samples, formation potential (FP) tests were conducted for regulated trihalomethanes (THMs), haloacetic …


Dynamic And Static Effects In Wetting Of Capillaries And Fibers, Taras Andrukh Dec 2012

Dynamic And Static Effects In Wetting Of Capillaries And Fibers, Taras Andrukh

All Dissertations

This research is centered on the analysis of static and dynamic effects of wetting of single capillaries and fibers. We discuss specifics of the capillary rise and drop-on-fiber techniques and develop new methods of characterization of surface energy of single fibers when its contact angle varies between zero and ninety degrees. The contact angles were evaluated and compared for different substrates. We study the dynamics of the meniscus formation inside and outside of capillaries and fibers. We develop a mathematical model of liquid uptake by capillaries and analyze the factors affecting liquid uptake. The derived fundamental equation describes the dynamics …


A Process Analysis Of Engineering Problem Solving And Assessment Of Problem Solving Skills, Sarah Grigg Dec 2012

A Process Analysis Of Engineering Problem Solving And Assessment Of Problem Solving Skills, Sarah Grigg

All Dissertations

In the engineering profession, one of the most critical skills to possess is accurate and efficient problem solving. Thus, engineering educators should strive to help students develop skills needed to become competent problem solvers. In order to measure the development of skills, it is necessary to assess student performance, identify any deficiencies present in problem solving attempts, and identify trends in performance over time. Through iterative assessment using standard assessment metrics, researchers/instructors are able to track trends in problem solving performance across time, which can serve as a gauge of students' learning gains.
This research endeavor studies the problem solving …


Synthesis And Characterization Of Nanoscale Fluorescent Polymer Films, Maryus Chyasnavichyus Dec 2012

Synthesis And Characterization Of Nanoscale Fluorescent Polymer Films, Maryus Chyasnavichyus

All Dissertations

Performance of the chemical sensing devices is based sensitivity to the targeted analytes and accuracy of the measurements. Of many different types of chemical sensors, fluorescence based sensing devices draw much attention as efficient yet small and straightforward devices, capable of detection of various analytes at extremely small quantities.
Polymeric materials provide support for the fluorescent materials and usually serve as a host for the chromophores, protecting them from harsh environments, and serve as a transport media for the analyte.
In the present study thin fluorescent polymer films, sensitive to the environment are synthesized and studied. Poly(glycidyl methacrylate) was used …


Phase Transformation In Ti-Mo-O, Herbert Boeckels Dec 2012

Phase Transformation In Ti-Mo-O, Herbert Boeckels

All Dissertations

The present dissertation has investigated the effect of oxygen on the ù and á phase stability in metastable Ti-Mo â titanium alloys using thermal analysis, hardness measurements, electron microscopy, and x-ray diffraction.
Single crystal x-ray diffraction has shown that oxygen atoms are located in the tetrahedral interstitial lattice sites in the rapidly cooled bcc Ti crystal structure, interfering directly with the reversible displacive formation of ù, with this transformation involving collapse of the bcc lattice along â. Subsequent thermal exposure of reversible ù, as occurring during slower cooling, heating, and aging, prompts short range diffusion and the formation of chemical …


Network Traffic Analysis Using Stochastic Grammars, Chen Lu Dec 2012

Network Traffic Analysis Using Stochastic Grammars, Chen Lu

All Dissertations

Network traffic analysis is widely used to infer information from Internet
traffic. This is possible even if the traffic is encrypted. Previous work uses
traffic characteristics, such as port numbers, packet sizes, and frequency,
without looking for more subtle patterns in the network traffic. In this work,
we use stochastic grammars, hidden Markov models (HMMs) and probabilistic
context-free grammars (PCFGs), as pattern recognition tools for traffic
analysis.
HMMs are widely used for pattern recognition and detection. We use a HMM
inference approach. With inferred HMMs, we use confidence intervals (CI) to
detect if a data sequence matches the HMM. To …