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Full-Text Articles in Engineering

Elastic Degradable Polyurethanes For Biomedical Applications, Changhong Zhang Dec 2006

Elastic Degradable Polyurethanes For Biomedical Applications, Changhong Zhang

All Theses

Several series of polyurethanes were synthesized with linear or crosslinked structures by using different synthesis routes. Two studies are mentioned: (1) the synthesis of degradable polyurethanes with linear structure and the investigation of the elasticity and cytophilicity of the materials as function of the chain extender, and (2) the synthesis and the investigation of the biocompatibility, degradation, hydrophilicity and mechanical properties of the polyurethane-based hydrogels with crosslinked structure.


Influence Of Socio-Economic And Demographic Factors On Crashes In Rural South Carolina At Sub-County Level, Sunil Jakhadi Dec 2006

Influence Of Socio-Economic And Demographic Factors On Crashes In Rural South Carolina At Sub-County Level, Sunil Jakhadi

All Theses

State of South Carolina ranks high in the fatality rates. The state is a predominately a rural state with more percentage of rural roads. This research focuses on the statistical variation of crash rates between the county and block-group, especially rural once to the state. Also, it focuses on the possibility of various socio-economic and demographic characters influence on the high crash rates particularly in rural South Carolina.
Crash database for the year 2004 was acquired from South Carolina Department of Transportation and was processed by the research team at Clemson University. This processed database was imported into GIS. Spatial …


Validation Of An Inertial Sensor System For Quantifying Knee Function, Aaron Koslin Dec 2006

Validation Of An Inertial Sensor System For Quantifying Knee Function, Aaron Koslin

All Theses

Gait analysis has become a useful tool for clinicians in evaluating the progression of pathologies through functional analysis. The high cost and dedicated laboratories associated with the traditional camera-based motion analysis systems present the need for an alternative system. Direct measurement of kinetic parameters using inertial sensors (gyroscopes and accelerometers), in place of indirect calculations from position data obtained using cameras, has been shown effective in resolving important gait parameters.
In order to directly compare gait parameters obtained using inertial sensors and a camera system, data was simultaneously collected from both systems for seven test subjects during normal gait. Three …


Life Cycle Cost Analysis Of Pavements: State-Of-The-Practice, Zeynep Guven Dec 2006

Life Cycle Cost Analysis Of Pavements: State-Of-The-Practice, Zeynep Guven

All Theses

Life Cycle Cost Analysis (LCCA) is performed by transportation agencies in the design phase of transportation projects in order to be able to implement more economical strategies, to support decision processes in pavement type selection (flexible or rigid) and also to assess the relative costs of different rehabilitation options within each type of pavement. However, most of the input parameters are inherently uncertain. In order to implement the LCCA process in a reliable and trustworthy manner, this uncertainty must be addressed. This thesis summarizes a through research that aims at improving the existing LCCA approach for South Carolina Department of …


Effect Of South Caroline Belt Law On Safety Belt Use, Sourabh Patki Dec 2006

Effect Of South Caroline Belt Law On Safety Belt Use, Sourabh Patki

All Theses

A number of factors and accessories help save lives and prevent injuries to road users, yet safety belts have become synonymous with automobile safety today, unlike any accessory before or since their introduction in automobiles. However, the scientific advances in automobile safety, followed by the acceptance of the necessity for safety in automobiles by both the manufacturers and the population, finally leading to the introduction of safety features and their incorporation within the laws occurred over a much longer span, continuing even today. Today's Safety movement aims at increasing safety belt using an awareness campaigns, accompanied by enforcement. Safety belt …


Optimizing Production Methods For Artifical Silk Proteins Through Bioreactor And Purification Studies Of Recombinant Proteins Expressed From Pichia Pastoris, Aaron Ramey Dec 2006

Optimizing Production Methods For Artifical Silk Proteins Through Bioreactor And Purification Studies Of Recombinant Proteins Expressed From Pichia Pastoris, Aaron Ramey

All Theses

Advancements in the field of biomaterials are being made to produce an artificial silk fiber. A gene was constructed which utilized components from both the dragline silk of Nephila clavipes and nematode collagen. For this engineered protein, the yeast strain Pichia pastoris was chosen to be the host organism. Previous research has shown P. pastoris to have comparatively low amounts of specific protein productivity. Therefore, this problem must be compensated for by obtaining extremely high cell densities. The main focus of this study was to optimize the fermentation parameters of transgenic yeast cultures within a bioreactor in order to increase …


Tannic Acid Crosslinked Collagens And Potential For Breast Tissue Engineering, Cheryl Parzel Dec 2006

Tannic Acid Crosslinked Collagens And Potential For Breast Tissue Engineering, Cheryl Parzel

All Theses

The purpose of this study was to develop and assess a potential key feature in a minimally-invasive breast reconstruction device and to collect information for an in vitro tissue test system. Tannic acid is a hydrolysable plant tannin, and it has been determined that tannic acid functions as a collagen crosslinking agent through both hydrogen bonding mechanisms and hydrophobic effects. Additionally, current research suggests that tannic acid may have anti-tumor properties. Therefore, it has been proposed that tannic acid can be used as an agent to induce apoptotic processes in any transplanted adult stem cells that are inclined to spontaneously …


Emission Reduction In Small Displacement Diesel Engines Using Cooled Exhaust Gas Recirculation, Chris Simoson Dec 2006

Emission Reduction In Small Displacement Diesel Engines Using Cooled Exhaust Gas Recirculation, Chris Simoson

All Theses

A reduced-order dynamic model is presented and experimentally validated to demonstrate the use of cooled exhaust gas recirculation to alleviate the tradeoff between nitric oxide reduction and performance preservation in a small displacement diesel engine. Exhaust gas recirculation (EGR) is an effective method for internal combustion engine oxides of nitrogen (NOx) reduction, but its thermal throttling diminishes power efficiency. The capacity to cool exhaust gases prior to merging with intake air may achieve the desired pollutant effect while minimizing engine performance losses.
Simulation and experimental results revealed significant NOx reductions throughout all testing scenarios using EGR, but also experienced a …


Haptics In Robotics And Automotive Systems, Erhun Iyasere Dec 2006

Haptics In Robotics And Automotive Systems, Erhun Iyasere

All Theses

Haptics is the science of applying touch (tactile) sensation and control to interaction with computer applications. The devices used to interact with computer applications are known as haptic interfaces. These devices sense some form of human movement, be it finger, head, hand or body movement and receive feedback from computer applications in form of felt sensations to the limbs or other parts of the human body. Examples of haptic interfaces range from force feedback joysticks/controllers in video game consoles to tele-operative surgery. This thesis deals with haptic interfaces involving hand movements. The first experiment involves using the end effector of …


Hierarchical State Estimation For Wide Area Power Systems, Srivatsan Lakshminarasimhan Dec 2006

Hierarchical State Estimation For Wide Area Power Systems, Srivatsan Lakshminarasimhan

All Theses

This thesis presents the application of hierarchical state estimation techniques to consolidate the state output of a wide area power system network. In a wide area network a large number of interconnections exist between various utilities of the wide area. Power transactions between areas occur over large distances and hence for better security there is a need to monitor the state of the entire wide area systems. Hierarchical state estimation is preferred over integrated state estimation, due to the reduced computational time.
Using existing state estimators of the member utilities of the wide area in the bottom level of hierarchical …


Influence Of Temperature And Polymer/ Mold Surface Interactions On Micro-Feature Replication At Ambient Pressure In Micro Injection Molding, Varun Thakur Dec 2006

Influence Of Temperature And Polymer/ Mold Surface Interactions On Micro-Feature Replication At Ambient Pressure In Micro Injection Molding, Varun Thakur

All Theses

This study assesses micro-feature replication at elevated mold temperature and ambient pressure using a variety of polymers. Moldings were made on the surface of stainless steel and silicon wafers containing features as small as 130 nm under isothermal conditions in a heated chamber by allowing polymer to spread over the features at ambient pressure. Feature replication was analyzed via AFM and SEM. Polymer behavior was characterized via melt contact angle and melt viscosity. While feature detail was well replicated, the moldings exhibited poor dimensional accuracy due to shrinkage. In general, polymers with low viscosity and surface tension comparable to the …


Development Of A Cellular Fiber Spinning Technology For Regenerative Medicine, Willie Jones Dec 2006

Development Of A Cellular Fiber Spinning Technology For Regenerative Medicine, Willie Jones

All Theses

In order to prove that our textile hollow fiber spinning apparatus was adequate for cellular encapsulation, we confirmed the viability and metabolic activity of green fluorescent protein (GFP) labeled bovine mammary epithelial cells (MAC-Ts) that were encapsulated in either the wall or lumen of alginate fibers. After a 21 day in vitro macroscopic evaluation, no decrease in fluorescence was observed; and it was determined that MAC-Ts encapsulated under both methods produced lactic acid and consumed glucose. Histomorphological analyses revealed that the diameter of the MAC-Ts increased under both encapsulation scenarios, with little to no evidence of cell cluster propagation. Based …


Dielectric Properties And Method Of Characterizing Ceramic Powders And Multiphase Composites, Ravi Kiran Kota Dec 2006

Dielectric Properties And Method Of Characterizing Ceramic Powders And Multiphase Composites, Ravi Kiran Kota

All Theses

Barium Titanate was the first developed ferroelectric ceramic material and even today it is widely used. It is also a well-known material used for capacitors. The only reason behind a wide range of applications is that barium titanate boasts of high dielectric properties. A phase transition from cubic to tetragonal at normal working temperatures provides enhanced dielectric properties in this electronic material. For any application and design, the most inquired property is the dielectric constant. Predicting the dielectric constant is very much required as it is the pre-requisite. This is the major objective of the present work. To estimate the …


Nonlinear Control Techniques For Robot Manipulators, Nitendra Nath Dec 2006

Nonlinear Control Techniques For Robot Manipulators, Nitendra Nath

All Theses

This Masters thesis describes the design and implementation of control strategies for the following topics of research: i) Whole Arm Grasping Control for Redundant Robot Manipulators, ii) Neural Network Grasping Controller for Continuum Robots and, iii) Coordination Control for Haptic and Teleoperator Systems.

An approach to whole arm grasping of objects using redundant robot manipulators is presented. A kinematic control which facilitates the encoding of both the end-effector position, as well as body self-motion positioning information as a desired trajectory signal for the manipulator joints is developed.

An approach is presented to whole arm grasping control for continuum robots. The …


Simulation And Characterization Of Tire Nonuniformity-Induced Steering Nibble Vibrations Through Integrated Subsystems Modeling, Derek Mangun Dec 2006

Simulation And Characterization Of Tire Nonuniformity-Induced Steering Nibble Vibrations Through Integrated Subsystems Modeling, Derek Mangun

All Theses

Periodic force variations produced by nonuniform tire/wheel assemblies are known root causes of torsional steering wheel vibrations known as 'nibble'. Previous studies have sought to investigate this issue through modeling or experimentation involving the entire vehicle or specific subsystems, however a direct link between objectively measured tire force variations and the vibration levels perceived by vehicle occupants has yet to be established. Analytical models of a nonuniform tire, double-wishbone suspension system, and rack and pinion steering system are sourced from literature and integrated into a single subsystem-level model validated against experimental data obtained as part of a collaborative effort. The …


Best Practices For Developing The Engineer's Estimate, Karl Niedzwecki Dec 2006

Best Practices For Developing The Engineer's Estimate, Karl Niedzwecki

All Theses

The research project 'Best Practices for Developing the Engineering Estimate' was executed by Clemson University on behalf of the South Carolina Department of Transportation (SCDOT). The primary objective of this research project was to investigate the strengths and weaknesses of two types of estimating methods being utilized today by state department of transportations (DOT) nationwide. These two types of estimating methods are the unit cost line item approach, which the SCDOT utilizes, and the cost-based estimating approach. This research report identifies accuracy obtained, resources expended, and methodologies utilized when implementing either type of estimating approach. This was done so the …


Developing A Benchmark Suite For The Evaluation Of Orientation Sensors, Kelly Waller Dec 2006

Developing A Benchmark Suite For The Evaluation Of Orientation Sensors, Kelly Waller

All Theses

This paper examines the problem with the lack of standardization through which MEMS orientation sensors are evaluated. These sensors are sold with data sheets that outline their performance, but lack the conditions under which the testing takes place. In this research, a testing apparatus was developed, and testing routines were designed to evaluate the different characteristics of orientation sensors under different motion conditions. Three orientation sensors, each in a different price range, were evaluated with the benchmark suite. The testing apparatus is a turntable that can precisely spin an orientation sensor via a stepper motor, and can record its exact …


Evaporation Estimation Using A Floating Pan, Michael Klink Dec 2006

Evaporation Estimation Using A Floating Pan, Michael Klink

All Theses

Almost all regions in the United States must accurately estimate evaporation to have effective water management programs. The purpose of this study is to develop a better method for measuring evaporation. Lake evaporation along with meteorological data are measured directly from a floating pan. The floating pan is specifically designed to account for one of the most sensitive parameters of evaporation, the water surface temperature, which the design achieves. However, other design factors such as air movement, solar radiation, stability, heat transfer, wave action, water level range, and site location were also taken into consideration. The evaporation measured from the …


Optimizing The Project Team's Contribution To Business Objectives, Chad Rowland Dec 2006

Optimizing The Project Team's Contribution To Business Objectives, Chad Rowland

All Theses

The traditional expectations of the project team are for the processes of engineering, procurement, construction, and start-up to be expertly administered. However, these performance criteria can be satisfied yet still not meet the ultimate business needs of the owner. The purpose of this thesis was to determine ways to improve the likelihood of achieving owner's business objectives. Fifty-one questionnaire survey forms were analyzed to obtain data for thirty-three pre-project planning activities. A data analysis concluded with a degree of statistical significance that for thirteen of the thirty-three activities, the more successful projects, as defined by the satisfaction of the business …


A Cross-Layer Approach To Increase Spatial Reuse And Throughput For Ad Hoc Networks, Steven Boyd Dec 2006

A Cross-Layer Approach To Increase Spatial Reuse And Throughput For Ad Hoc Networks, Steven Boyd

All Theses

Ad hoc networks employing adaptive-transmission protocols can alter transmission parameters to suit the channel environment. Channel-access mechanisms are used to govern temporal use of the transmission medium amongst nodes. Effective operation of a channel-access mechanism can improve the ability of an adaptive-transmission protocol to accommodate changing channel conditions. The interoperability of these two mechanisms motivates cross-layer design of adaptive-transmission protocols.
In this thesis we examine the integration of a new channel-access mechanism with a physical-layer adaptive-transmission protocol to create a cross-layer protocol with enhanced capabilities. We derive specific physical-layer measurements which are used to control channel-access behavior in a distributed …


Using A Spline To Model The Motion Of A 4-Man Fireteam During Building Clearing Exercises, Marshall Werner Dec 2006

Using A Spline To Model The Motion Of A 4-Man Fireteam During Building Clearing Exercises, Marshall Werner

All Theses

This paper examines the problem of tracking positions of a fireteam (4-5 men) as they perform building clearing exercises in order to predict future motion od the team. This was done by examining the team as a single entity rather than 4 or 5 separate entities. A team model was used under the assumption that the team stays together as a group and moves in specific patterns. The model chosen for this experiment was a spline curve. This spline curve allowed for movement in straight lines through hallways as well as curving around corners.


A Comparison Of The Zns(Ag) Scintillation Detector To The Silicon Semiconductor Detector For Quantification Of Alpha Radioactivity In Aqueous Solutions, Jennifer Foster Dec 2006

A Comparison Of The Zns(Ag) Scintillation Detector To The Silicon Semiconductor Detector For Quantification Of Alpha Radioactivity In Aqueous Solutions, Jennifer Foster

All Theses

A ZnS(Ag) detector was successfully used in the direct detection of alpha particles from aqueous solutions and the results were compared to the passivated ion implanted planar silicon (PIPS) continuous air monitor (CAM) detector. The ZnS(Ag) detector is recommended for on-line detection of gross alpha radioactivity from high-level liquid waste process streams; however, the detector suffers from limitations due to variations in detection efficiency with alpha energies. The beta and gamma interference did not significantly spillover into the alpha region of interest of the ZnS(Ag) detector which provided absolute detection efficiencies of 7.19 ± 0.13%, 5.37 ± 0.02%, and 4.21 …


The Effects Of Viscoelastic Behavior On The Operation Of A Delayed Resonator Vibration Absorber, John Cowans Dec 2006

The Effects Of Viscoelastic Behavior On The Operation Of A Delayed Resonator Vibration Absorber, John Cowans

All Theses

Delayed resonators have proven to be effective vibration absorbers (VAs) for tracking and canceling the effects of harmonic excitations on a structure. The Delayed Resonator (DR) is selfcontained, as no information from outside of its substructure is required for proper operation. It adjusts for variations in frequency using time-delay and gain as control parameters.
This thesis examines the relationship between viscoelastic (VE) loss mechanisms in systems with DR and the choice of modeling method used to calculate control parameters and determine system stability. It is hypothesized that a VE loss mechanism approximated by a single viscous dashpot may lead to …


Soccer Headgear Effects On Impact Profiles During A Heading Scenario, Ryan Posey Dec 2006

Soccer Headgear Effects On Impact Profiles During A Heading Scenario, Ryan Posey

All Theses

The risk of head injuries in the sport of soccer has recently become a topic of concern, particularly with youth players whom may suffer long-lasting or even permanent effects from a severe head injury. In response to these worries, headguards have been developed specifically for use in soccer. These headguards have been studied using crash test dummy heads mounted with various electronic instruments - accelerometers, gyroscopes, etc. The headgear-mounted dummy heads have been struck with various objects (soccer ball, another dummy head, pole, etc) to test for changes in head acceleration response.
Testing of soccer headgear has previously been limited …


Internal Combustion Engine Cooling Strategies: Theory And Test, John Chastain Dec 2006

Internal Combustion Engine Cooling Strategies: Theory And Test, John Chastain

All Theses

Advanced internal combustion engine thermal management systems can enhance overall engine performance through the use of computer controlled cooling system actuators. Existing ground vehicle cooling systems generally have performance limitations due to the fixed behavior of the wax-based thermostat valve and crankshaft dependent operation of the coolant pump and radiator fan. Upgrading the traditional thermostat valve, water pump, and radiator fan with actuators permit real time computer control for improved temperature tracking and reduced power consumption. In this paper, the benefits associated with advanced automotive cooling systems are experimentally investigated. A 4.6L engine with a real-time data acquisition and control …


The Effects Of Calcium Magnesium Acetate Deicers On Portland Cement Mortar Bars, Jeffrey Davis Dec 2006

The Effects Of Calcium Magnesium Acetate Deicers On Portland Cement Mortar Bars, Jeffrey Davis

All Theses

This thesis involves the investigation of the effects of Calcium Magnesium Acetate (CMA) deicers on Portland cement mortar bars. In addition to mass-loss, length change, pulse velocity and soak solution pH, the thesis also contains a rigorous chemical analysis of the mortar completed at the National Institute of Standards and Technology (NIST) in Gaithersburg, MD. The research completed at NIST was done using a technique known as X-ray Mapping. The X-ray techniques were employed to determine the exact nature of the damage caused by CMA. The thesis is a combination of two papers, on the physical effects of CMA and …


Unsupervised Neural Pattern Classifiers For Oral Vowel Pronunciation Of Foreign-Accented Speech, Joseph Hecker Dec 2006

Unsupervised Neural Pattern Classifiers For Oral Vowel Pronunciation Of Foreign-Accented Speech, Joseph Hecker

All Theses

This thesis describes the development of unsupervised neural-based pattern classifiers for the training of vowel pronunciations for students learning a foreign language. This paper examines American learners of the French language. A corpus of single word utterances is compiled from a group of native French speakers. Cepstral features are used to train two unsupervised neural pattern classifiers: a self-organizing map and a growing neural gas. The development and justification for the use of these classifiers is presented. The output from the classifier is translated to a bar graph for visual assessment. The degree to which the utterance sounds native is …