Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Clemson University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 2521 - 2550 of 2584

Full-Text Articles in Engineering

Study Of Structure Development During Melt Spinning Of Isotactic Polypropylene Fibers Using Raman Spectroscopy And Wide Angle X-Ray Diffraction Simultaneously , Dushyanth Pandana Jan 2007

Study Of Structure Development During Melt Spinning Of Isotactic Polypropylene Fibers Using Raman Spectroscopy And Wide Angle X-Ray Diffraction Simultaneously , Dushyanth Pandana

All Theses

ABSTRACT
Isotactic polypropylene (iPP) fibers have a wide variety of applications. Specific end-use applications require specific properties, which are dependent on the polymer morphology produced during processing. Therefore, the final properties of a material are dependent on the processing parameters. iPP fibers are produced mainly by melt spinning. The important processing parameters in the melt spinning process include, the extrusion temperatures, the throughput and shear rates, the rate of cooling, and the feed and draw roll take-up velocities. An understanding of how the morphology develops along the spinline, and the effect of processing parameters on the morphology is crucial in …

Go to article

Comparative Study Of Haptic And Visual Feedback For Kinesthetic Training Tasks, Ravikiran Singapogu Jan 2007

Comparative Study Of Haptic And Visual Feedback For Kinesthetic Training Tasks, Ravikiran Singapogu

All Theses

Haptics is the sense of simulating and applying the sense of human touch. Application of touch sensations is done with haptic interface devices. The past few years has seen the development of several haptic interface devices with a wide variety of technologies used in their design. This thesis introduces haptic technologies and includes a survey of haptic interface devices and technologies. An improvement in simulating and applying touch sensation when using the Quanser Haptic Wand with proSense is suggested in this work using a novel five degree-of-freedom algorithm. This approach uses two additional torques to enhance the three degree-of-freedom of …

Go to article

Synthesis And Photocatalysis Study Of Brookite Phase Titanium Dioxide Nanoparticles, Radhika Bhave Jan 2007

Synthesis And Photocatalysis Study Of Brookite Phase Titanium Dioxide Nanoparticles, Radhika Bhave

All Theses

Titanium dioxide is used in variety of applications like photocatalysis, self-cleaning coatings, fog proof glass and water purifier. A lot of research is being done in synthesis and applications of TiO2. Titanium dioxide or TiO2 mainly exists in three phases namely anatase, brookite and rutile. Current studies relate to synthesis of brookite phase TiO2 nanoparticles by ambient condition sol (ACS) process and characterization of these particles for phase purity, morphology and surface area analysis. The photoactivity of these particles was investigated and absorption in the visible light region was detected. This implies brookite to have good potential to be used …

Go to article

Application Of Classical Versus Bayesian Statistical Methods To On-Line Radiological Monitoring, Amy Attardo Jan 2007

Application Of Classical Versus Bayesian Statistical Methods To On-Line Radiological Monitoring, Amy Attardo

All Theses

The on-line monitoring for illicit radioactive material with a minimum number of false detections is a critical need for homeland security. The primary objectives of this work were to apply both Bayesian and classical statistical process control chart techniques to the on-line monitoring of radiological data and to then compare the Type I and Type II error incidence rates. Two versions of the cumulative sum (CUSUM) and Shiryayev-Roberts (S-R) procedures known as total reset and alarm reset methods were developed. The best method in terms of Type I errors was the S-R total reset method. In terms of Type II …

Go to article

Dynamic Networking Of Exemplars: Towards A Mechanical Design Visual Programming Language, Shashidhar Putti Jan 2007

Dynamic Networking Of Exemplars: Towards A Mechanical Design Visual Programming Language, Shashidhar Putti

All Theses

Developing mechanical engineering design automation applications using current day textual programming languages like C, C++ requires extensive programming skills. However, learning to program in these environments can be time consuming and often frustrating to mechanical engineers due to the use of complex textual constructs and syntax to represent an algorithm in a linear fashion. Further, these programming languages offer a poor visualization of the data and the data flow due to their textual nature. The use of graphical objects for programming makes visualization easier and also eliminates the need for linear representation of algorithms. This thesis initiates the development of …

Go to article

Impulsive-Actuation Part Positioning Through Constrained Energy Balance Planning, Laine Mears, Thomas R. Kurfess Jan 2007

Impulsive-Actuation Part Positioning Through Constrained Energy Balance Planning, Laine Mears, Thomas R. Kurfess

Publications

Impulsive actuation has been researched in the past two decades as an inexpensive alternative to multi-degree-of-freedom precision positioning systems. The position of a sliding workpiece can be controlled by a 2-degree-offreedom actuation system through simple pushing path planning. However, the final part position as a result of the last touch of the actuator is subject to uncertainty in the friction model used for actuation planning, particularly the free-sliding distance undergone by the workpiece after losing contact with the actuator. This paper first reviews an impact planning method, then augments it using a restitutionbased model that results in an explicit actuator …

Go to article

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.

Go to article

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 …

Go to article

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 …

Go to article

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 …

Go to article

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 …

Go to article

Elevated Neutral-To-Earth Voltage In Distribution Systems Including Harmonics, Jian Jiang Dec 2006

Elevated Neutral-To-Earth Voltage In Distribution Systems Including Harmonics, Jian Jiang

All Dissertations

The elevated neutral-to-earth voltage (NEV), and the related phenomenon called stray voltage, is analyzed in multigrounded distribution systems. Elevated NEV is typically caused by fundamental frequency currents returning to the source via the neutral conductor and earth. However, harmonic distortion is also found to contribute to elevated NEV. A multiphase harmonic load flow algorithm is developed to examine the effects of various factors on the NEV, including unsymmetrical system configuration, load unbalance and harmonic injection. To fulfill this objective, the system modeling is adapted to include the neutral conductor into the component equivalent circuit. The overhead transmission line is remodeled …

Go to article

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 …

Go to article

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 …

Go to article

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 …

Go to article

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 …

Go to article

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 …

Go to article

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 …

Go to article

Development Of Fatigue Predictive Models Of Rubberized Asphalt Concrete (Rac) Containing Reclaimed Asphalt Pavement (Rap) Mixtures, Feipeng Xiao Dec 2006

Development Of Fatigue Predictive Models Of Rubberized Asphalt Concrete (Rac) Containing Reclaimed Asphalt Pavement (Rap) Mixtures, Feipeng Xiao

All Dissertations

In recent years, some by-products such as crumb rubber has been used to save money, protect the environment, and extend the life of asphalt pavements. In addition, the utilization of reclaimed asphalt pavement (RAP) is an acceptable practice in many states around the United States and many countries all over the world. However, the use of RAP containing crumb rubber has not been investigated in great detail, so it is essential to explore whether these materials have a positive effect on the fatigue life of asphalt pavement. In general, previous experience shows that the use of RAP has proven to …

Go to article

A Multidimensional Scaling And Participatory Design Approach To Classify Open Ended Aircraft Maintenance Data, Kunal Kapoor Dec 2006

A Multidimensional Scaling And Participatory Design Approach To Classify Open Ended Aircraft Maintenance Data, Kunal Kapoor

All Dissertations

The quality assurance data to be analyzed by the web-based surveillance and auditing tool (WebSAT) is both qualitative and quantitative. The forced responses to checklist questions provide a definitive outcome identifying the effectiveness of the four quality assurance work functions. On the other hand, open-ended responses, the second type of response for capturing maintenance errors, are qualitative in nature since they reflect what the auditors and quality assurance representatives observe during their interactions at vendor locations. This research proposes to apply the statistical technique of multidimensional scaling (MDS) and the User centered Design (UCD) method of Participatory Design (PD) to …

Go to article

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 …

Go to article

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 …

Go to article

Modeling Of The Transient Behavior Of Heat Pipes With Room-Temperature Working Fluids, Pascal Brocheny Dec 2006

Modeling Of The Transient Behavior Of Heat Pipes With Room-Temperature Working Fluids, Pascal Brocheny

All Dissertations

The heat pipe is a capillary-driven and two-phase flow device, capable of transporting and converting large amounts of energy with minimal losses. As a means of thermal management, uses of heat pipe technology not only include thermal control of satellites and spacecrafts in aerospace applications, but also the cooling of electronic components for ground applications. Recently, there has been a flourishing interest in exploring the use of heat pipe technology in the automotive field. However, in many thermal control applications, heat pipes using room-temperature working fluids, such as water or ammonia, with operating temperatures between 200 K (-73ºC) and 550 …

Go to article

Investigation Of Flow And Microstructure In Rheometric And Processing Flow Conditions For Liquid Crystalline Pitch, Santanu Kundu Dec 2006

Investigation Of Flow And Microstructure In Rheometric And Processing Flow Conditions For Liquid Crystalline Pitch, Santanu Kundu

All Dissertations

A fundamental understanding of flow and its influence on the microstructure is required to obtain carbon materials with desired properties. The objective of this research was to investigate the flow and microstructural behavior of a synthetic mesophase pitch (AR-HP) in rheometric and processing flow conditions. In addition, simulation studies were performed to establish a frame work for modeling the flow behavior of this complex material in different flow situations.
The steady-shear viscosities obtained from a cone-plate rheometer during increasing rate-sweep experiments exhibited a shear-thinning region (Region I) with a slope of about -0.2 and a plateau (Region II) region. The …

Go to article

Use Of Personas For User Interface Design: Results Of Field And Experimental Studies , Pallavi Dharwada Dec 2006

Use Of Personas For User Interface Design: Results Of Field And Experimental Studies , Pallavi Dharwada

All Dissertations

Persona is a fictitious user serving as a role model for designers, helping them make difficult decisions from the users' perspective during the interface design process. This concept, which was introduced by Alan Cooper in 1999, has been found to be a powerful tool for engaging the designers with the users. Although personas do not replace the rich data acquired through user testing, they enhance the interface development process by focusing the designers' attention on the target user until the interface qualifies for testing. Recognizing the benefits of persona, many companies, including the Fortune 500 have embraced this concept as …

Go to article

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 …

Go to article

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 …

Go to article

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 …

Go to article

Tribological Systems For The Evaluation Of Supercritical Carbon Dioxide Sterilized Ultra-High Molecular Weight Polyethylene, John Desjardins Dec 2006

Tribological Systems For The Evaluation Of Supercritical Carbon Dioxide Sterilized Ultra-High Molecular Weight Polyethylene, John Desjardins

All Dissertations

Polymeric biomaterials are especially susceptible to changes in mechanical and surface material properties as a result of sterilization processes that involve heat, moisture and/or irradiation. This is problematic for polymeric materials used in total joint replacement bearings, as these constructs must retain their superior mechanical and tribological properties over their expected 10-20 years of implantation. A younger more active patient population has now exacerbated this longevity issue with service lifetimes of 20+ years now being expected. Supercritical phase carbon dioxide (SC-CO2) is an industrial solvent that has shown great promise as a sterilizing agent in the food industry. Recently, SC-CO2 …

Go to article

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 …

Go to article

First Prev Next Last