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 2191 - 2220 of 2584

Full-Text Articles in Engineering

Operation Assessment Of Reservoirs In The Savannah River Basin, Travis Yates Aug 2009

Operation Assessment Of Reservoirs In The Savannah River Basin, Travis Yates

All Theses

Hydropower is generated from three reservoirs in the United States Army Corps of Engineer's Savannah District. These reservoirs include J. Strom Thurmond, Richard B. Russell, and Hartwell. Currently, a contract in place specifies that certain amount of energy must be provided to the region. The contract for the hydropower was based upon the critical hydrologic year of 1981. Historically, this was the most severe drought on record and assumed to provide the lowest net inflows for the three reservoirs, thus providing an attainable or reliable energy amount for the system, which suggests a dependable energy yield.
Reevaluating the contract amount …

Go to article

The Effect Of Relative Humidity On The Microbial Barrier Properties Of Porous Packaging Materials Used In The Medical Device Industry, Jennifer Blocher Aug 2009

The Effect Of Relative Humidity On The Microbial Barrier Properties Of Porous Packaging Materials Used In The Medical Device Industry, Jennifer Blocher

All Theses

Porous packaging materials, such as medical-grade paper and Tyvek¨, are used often by the medical device industry for packaging sterile devices when the products are sterilized post packaging. Their use can be attributed to the fact that multiple sterilization methods require the ability for vapors to enter and/or exit the package efficiently, while simultaneously reducing the amount of microbes entering the package. Much research as been done to study the effects of multiple material and environmental factors, such as material structure and dispersion concentration, on the microbial barrier properties of these materials, however no research had been conducted to examine …

Go to article

Dynamic Finite Element Simulation Of Ultrasonic Consolidation, Daniel Mccullough Aug 2009

Dynamic Finite Element Simulation Of Ultrasonic Consolidation, Daniel Mccullough

All Theses

Ultrasonic Consolidation (UC) is a promising solid state rapid manufacturing process that provides the ability to create functional, multilayered, and often geometrically complex parts. This thesis seeks to address one of the primary obstacles faced when using the process, namely the apparent build height limit encountered when using UC to construct high aspect ratio specimens. A fully transient, three dimensional Finite Element model is created to study the dynamic behavior of an ultrasonically consolidated part during the UC process. The model is used to find the cause of bond failure at the build height limit and a potential way to …

Go to article

Effects Of Phase And Amplitude Errors On Qam Systems With Error-Control Coding And Soft Decision Decoding, Jason Ellis Aug 2009

Effects Of Phase And Amplitude Errors On Qam Systems With Error-Control Coding And Soft Decision Decoding, Jason Ellis

All Theses

Demodulation of M-ary quadrature amplitude modulation (M-QAM) requires the receiver to estimate the phase and amplitude of the received signal. The demodulator performance is sensitive to errors in these estimates, and the sensitivity increases as M increases. We examine the effects of phase and amplitude errors on the performance of QAM communication systems with error-control coding and soft-decision decoding. A mathematical analysis of these effects is presented for two soft-decision decoding metrics. Performance comparisons are given for 16-QAM and 64-QAM for two error-control coding techniques and two soft-decision decoding metrics.

Go to article

Biohydrogen Production From Cull Peach Medium By Hyperthermophilic Bacterium Thermotoga Neapolitana, Abhiney Jain Aug 2009

Biohydrogen Production From Cull Peach Medium By Hyperthermophilic Bacterium Thermotoga Neapolitana, Abhiney Jain

All Theses

ABSTRACT
Thermotoga neapolitana is a marine hyperthermophilic bacterium that ferments various sugars to hydrogen and acetate. In this study, cull peaches were used as carbon source in a defined medium for biohydrogen production and produced 18 % to 25% hydrogen in the headspace. The hydrogen production varied from 6.4-7.7 mmol H2/g peach (dry weight). The hydrogen concentration did not increase after 20 hours of incubation. The final pH decreased to 4.9 after 20 hours. Unautoclaved peach medium can be used for hydrogen production. The hydrogen production did not increase with the increase in peach concentration from 50 g/L to 100 …

Go to article

Leaching Of Dissolved Organic Carbon And Selected Inorganic Constituents From Scrap Tires, Meric Selbes Aug 2009

Leaching Of Dissolved Organic Carbon And Selected Inorganic Constituents From Scrap Tires, Meric Selbes

All Theses

An environmentally friendly method for the disposal of scrap tires is currently unavailable; as a result, ultimate disposal of used vehicle tires continues to be a major challenge around the world. In the United States (US), during the past two decades, scrap tires have been generated at the rate of approximately one tire per person per year (i.e., approximately 290 million new scrap tires every year). It is estimated that there are currently 2 billion tires stockpiled in the US. Due to various problems involved in the disposal of scrap tires, different alternatives for recycle and reuse have been examined; …

Go to article

Predictive Energy Management In Smart Vehicles: Exploiting Traffic And Traffic Signal Preview For Fuel Saving, Behrang Asadi Aug 2009

Predictive Energy Management In Smart Vehicles: Exploiting Traffic And Traffic Signal Preview For Fuel Saving, Behrang Asadi

All Theses

This master thesis proposes methods for improving fuel economy and emissions of vehicles via use of future information of state of traffic lights, traffic flow, and deterministic traffic flow models.
The first part of this thesis proposes use of upcoming traffic signal information
within the vehicle's adaptive cruise control system to reduce idle time at stop lights and lower fuel use. To achieve this goal an optimization-based control algorithm is formulated for each equipped vehicle that uses short range radar and traffic signal information predictively to schedule an optimum velocity trajectory for the vehicle. The objectives are timely arrival at …

Go to article

Modeling Nitrogen Loss From Regional Switchgrass Agriculture, Saumya Sarkar Aug 2009

Modeling Nitrogen Loss From Regional Switchgrass Agriculture, Saumya Sarkar

All Theses

A water quality modeling study was conducted to determine and compare nitrogen loss from agricultural systems growing switchgrass and cotton in the southeastern USA. The water quality impacts were modeled at the plot scale and at the watershed scale. The Soil and Water Assessment Tool (SWAT) was used to replicate field conditions observed at switchgrass research plots at Pee Dee Research and Educational Center at Florence, South Carolina. The plot scale modeling suggested that in the early years of growth there is significant nitrogen loss from switchgrass to streamflow and groundwater but they are significantly less as the switchgrass matures. …

Go to article

Synthesis And Polymorphic Control For Visible Light Active Titania Nanoparticles, Sujaree Kaewgun Aug 2009

Synthesis And Polymorphic Control For Visible Light Active Titania Nanoparticles, Sujaree Kaewgun

All Dissertations

Titania (TiO2) is useful for many applications in photocatalysis, antimicrobials, pigment, deodorization, and decomposition of harmful organics and undesirable compounds in the air and waste water under UV irradiation. Among the three phases of TiO2, Rutile, Anatase, and Brookite, studies have been more focused on the anatase and rutile phases.
Pure brookite is the most difficult phase to prepare, even under hydrothermal conditions. Predominantly brookite phase TiO2 nanoparticles were prepared by the Water-based Ambient Condition Sol (WACS) process in our laboratory. The objectives of this research were to enhance visible light active (VLA) photocatalytic properties …

Go to article

Development And Integration Of Geometric And Optimization Algorithms For Packing And Layout Design, Santosh Tiwari Aug 2009

Development And Integration Of Geometric And Optimization Algorithms For Packing And Layout Design, Santosh Tiwari

All Dissertations

The research work presented in this dissertation focuses on the development and application of optimization and geometric algorithms to packing and layout optimization problems. As part of this research work, a compact packing algorithm, a physically-based shape morphing algorithm, and a general purpose constrained multi-objective optimization algorithm are proposed. The compact packing algorithm is designed to pack three-dimensional free-form objects with full rotational freedom inside an arbitrary enclosure such that the packing efficiency is maximized. The proposed compact packing algorithm can handle objects with holes or cavities and its performance does not degrade significantly with the increase in the complexity …

Go to article

Moisture Susceptibility Of Asphalt Mixes Using Phosphonylated Recycled Polyethylene, David Herndon Aug 2009

Moisture Susceptibility Of Asphalt Mixes Using Phosphonylated Recycled Polyethylene, David Herndon

All Dissertations

ABSTRACT
Today's asphaltic concrete pavements are expected to perform better even though they are experiencing increased volume of traffic and increased loads over what has been experienced in the past. Research has indicated that the addition of polymers to asphalt binders can enhance many properties of the asphalt pavements to help meet these increased demands.
There remains a serious problem that the addition of polymers to asphalt binders generally does not address. This involves the interfacial cohesiveness of the bond between the aggregate and the binder. Some aggregates are highly hydrophilic (water-loving) while asphalt binders and most polymers tend to …

Go to article

Novel Techniques For The Synthesis Of Three-Way Catalytic Converter Support Materials, Prince Anyaba Aug 2009

Novel Techniques For The Synthesis Of Three-Way Catalytic Converter Support Materials, Prince Anyaba

All Dissertations

Current automobiles use catalytic converters, consisting of noble metals on an oxide support, to convert noxious engine exhaust pollutants into less harmful species. The development of mesoporous oxide supports with optimal pore geometries could enable these devises to decrease in size and weight and significantly reduce the metal loadings required to achieve optimal performance. Thus, in this work, I investigated a wide range of techniques for the synthesis of mesoporous oxides to determine if they could be adapted to ceria-zirconia-yttria mixed oxide (CZY) systems, which are the industry standard for the optimal oxide support for catalytic converter applications. Additionally, I …

Go to article

Creation Of Defined Single Cell Resolution Neuronal Circuits On Microelectrode Arrays, Russell Pirlo Aug 2009

Creation Of Defined Single Cell Resolution Neuronal Circuits On Microelectrode Arrays, Russell Pirlo

All Dissertations

The way cell-cell organization of neuronal networks influences activity and facilitates function is not well understood. Microelectrode arrays (MEAs) and advancing cell patterning technologies have enabled access to and control of in vitro neuronal networks spawning much new research in neuroscience and neuroengineering. We propose that small, simple networks of neurons with defined circuitry may serve as valuable research models where every connection can be analyzed, controlled and manipulated.
Towards the goal of creating such neuronal networks we have applied microfabricated elastomeric membranes, surface modification and our unique laser cell patterning system to create defined neuronal circuits with single-cell precision …

Go to article

Lyapunov-Based Coordinated Control Of An Underactuated Unmanned Aerial Vehicle And Robot Manipulator, Dongbin Lee Aug 2009

Lyapunov-Based Coordinated Control Of An Underactuated Unmanned Aerial Vehicle And Robot Manipulator, Dongbin Lee

All Dissertations

This Ph.D. dissertation describes nonlinear tracking control results for a quadrotor helicopter unmanned aerial vehicle (UAV) towards the ultimate goal of controlling a combined UAV plus robot manipulator system (UAVRM). The quadrotor UAV is a helicopter that has four independent rotors that provide vertical lift: these four independent forces are managed in order to directly provide lift, pitch, roll, and yaw of the vehicle. Horizontal translations result from pitch and roll actions, the system is underactuated in the sense that there are only four control inputs to move the six degree-of-freedom aircraft. There are exising dynamic models of the quadrotor …

Go to article

Design, Construction, And Testing Of A New Class Of Mobile Robots, Ivan Siles May 2009

Design, Construction, And Testing Of A New Class Of Mobile Robots, Ivan Siles

All Theses

This thesis introduces a novel mobile robot design concept aimed at exploration of subterranean spaces. The key innovation is the combination of highly maneuverable body elements with wheel/leg elements (Whegs). This combination offers performance not possible with conventional 'monolithic' wheeled or tracked mobile robots, or with current robot snakes. The thesis covers four design iterations of the concept, concentrating on describing the overall design process and results from field tests. Additionally a kinematic analysis of the fourth prototype and implications for future designs is presented.

Go to article

Warning! Engineers In Training: Introducing Middle School Students To Industrial Engineering, Its Usefulness, And Its Applications, M. Grubb, A. Berger, D. Browning, M. Mayorga, Laine Mears May 2009

Warning! Engineers In Training: Introducing Middle School Students To Industrial Engineering, Its Usefulness, And Its Applications, M. Grubb, A. Berger, D. Browning, M. Mayorga, Laine Mears

Publications

The McCants Middle School Pre-engineering class is designed to teach engineering skills to students with a predisposition for and interest in math and science. This team’s initiative is to use Industrial Engineering tools to enhance the existing pre-engineering course curriculum. The purpose of this study is to make middle school students better aware of an engineer’s thought process as it pertains to effectively planning and working on projects, and to measure the impact of our influence. Through this study, we want to improve the overall quality of the student’s projects and ultimately increase the retention and quantity of students interested …

Go to article

A Study In The Information Content, Consistency, And Expressive Power Of Function Structures In Mechanical Design, Chiradeep Sen May 2009

A Study In The Information Content, Consistency, And Expressive Power Of Function Structures In Mechanical Design, Chiradeep Sen

All Theses

In engineering design research, function structures are used to represent the intended functionality of technical artifacts. Function structures are graph-based representations where the nodes are functions, or actions, and the edges are flows, or objects of those actions. For the consistent description of artifact functionality, multiple controlled vocabularies have been developed in previous research. The Functional Basis is one such vocabulary that provides for a set of verbs and a set of nouns, organized in the three-level hierarchy. This vocabulary is extensively studied in design research. Two major application of this vocabulary are the Design Repository, which is a web-base …

Go to article

Rheological, Thermal And Processing Studies Of Perfluorocyclobutyl (Pfcb) Polymers, Erick Vasquez May 2009

Rheological, Thermal And Processing Studies Of Perfluorocyclobutyl (Pfcb) Polymers, Erick Vasquez

All Theses

Polymeric materials are of interest to the fiber optics industry as glass–silica fibers are prone to fracture. However, the thermal resistance properties of current polymeric materials have limited their use in some optical applications including high performance lasers and high speed telecommunication systems. Therefore, it is of interest to develop new polymer materials and systems with enhanced thermal properties and processability for application in optics. This work focuses on the novel Perfluorocyclobutyl (PFCB) polymer systems. PFCB polymers possess characteristics that make them suitable for optics applications including: a low refractive index, high thermal stability and high chemical resistance. However, little …

Go to article

Development Of A Falling Sphere Instrument For High-Resolution Neutral Wind Measurements In The Mesosphere And Lower Thermosphere, Arpan Shah May 2009

Development Of A Falling Sphere Instrument For High-Resolution Neutral Wind Measurements In The Mesosphere And Lower Thermosphere, Arpan Shah

All Theses

Passive falling spheres launched from small rockets have been used extensively in the past to measure the winds and densities in the mesosphere. In principle, the same technique can be extended to higher altitudes that cover the lower thermosphere, in addition to the mesosphere. The main difficulties are that accelerations decrease rapidly with height due to the decreasing atmospheric density and rigid spheres are required at higher altitudes, which implies larger mass and smaller accelerations. Accelerometers with broad dynamic range and high sensitivity are required for the measurements, but such devices are not readily available. We describe an instrumented falling …

Go to article

Investigation Of Roundoff Noise In Iir Digital Filters Using Matlab, Sierra Williams May 2009

Investigation Of Roundoff Noise In Iir Digital Filters Using Matlab, Sierra Williams

All Theses

As technology increases, more and more devices are becoming digital. The typical purpose of a digital filter is to detect unwanted signals and noise and remove them by filtering. The infinite impulse response (IIR) filter is also called a recursive filter because of the feedback necessary during implementation. A filter can be expressed as a cascade of second-order sections (SOS). For N sections, there are (N!) ways to pair the poles and zeros. There are also (N!) ways to order the resulting second-order sections, for a total of (N!)2 different filter configurations for implementation. In this thesis, for a 6th …

Go to article

An Investigation Of Human Induced Vibrations On Clemson Memorial Stadium, Benjamin Morris May 2009

An Investigation Of Human Induced Vibrations On Clemson Memorial Stadium, Benjamin Morris

All Theses

Human induced stadium vibrations have become of increasing concern to design engineers and facility managers as more energetic crowds and increasingly efficient structures have increased the likelihood of serviceability issues. The 'in-time' bouncing of spectators due to music has caused one such issue in the south upper deck of Clemson University's Memorial Stadium. To gain an understanding of the severity of vibrations in Memorial Stadium, a combination of experimental and analytical modeling is utilized. Data collected by an array of accelerometers installed on a main post tensioned precast cantilever girder provides a season and a half of response histories in …

Go to article

Cardiac Cell Mechanics At The Single Cell Level, John Mcrae May 2009

Cardiac Cell Mechanics At The Single Cell Level, John Mcrae

All Theses

The analysis of the cellular microenvironment is an area that has received much
attention recently in the study of the tractions cells use for locomotion. Specifically, the
study of cardiac cell mechanics is of particular interest as cardiac dysfunction is one of
the leading causes of death in America. This progression is fueled by the need to have a
system capable of reproducing mechanical environments before, during and after a
dysfunctional event in order to fully characterize the causes and prevent any permanent
damage. The current study proposes a system capable of providing quantitative
measurements of the cellular microenvironment while …

Go to article

A Priori Analysis Of Subgrid Scalar Phenomena And Mass Diffusion Vectors In Turbulent Hydrogen-Oxygen Flames, Justin Foster May 2009

A Priori Analysis Of Subgrid Scalar Phenomena And Mass Diffusion Vectors In Turbulent Hydrogen-Oxygen Flames, Justin Foster

All Theses

Direct Numerical Simulations (DNS) of high pressure, turbulent H2/O2 non-premixed flames employing real gas effects, detailed chemistry, multicomponent, differential, and cross diffusion are conducted. The results of these simulations are analyzed to provide important subgrid information relevant to Large Eddy Simulation (LES) of turbulent combustion. Subgrid filtered scalar dissipation and scalar variances, species concentrations, reaction rates, and flame temperature are presented as a function of mixture fraction. The analysis also includes a detailed comparison of the actual filtered mass flux vectors with their corresponding forms evaluated with the filtered primitive variables. The results show a reasonable correlation …

Go to article

Synthesis And Analysis Of Nano-Thin Polymer Films For Separation Applications, Azadeh Samadi-Dezfouli May 2009

Synthesis And Analysis Of Nano-Thin Polymer Films For Separation Applications, Azadeh Samadi-Dezfouli

All Dissertations

This dissertation focuses on the fabrication of uniform polymer nanolayers using surface-initiated polymerization. The kinetics of low temperature surface-initiated atom transfer radical polymerization (ATRP) is discussed in detail. The work is then extended to the surface modification of polymeric membranes to tune the physical and chemical properties of the membranes for gas separations. I discuss how atom transfer radical polymerization might be advantageous compared to some of the techniques that have been proposed in the literature for preparing polymeric membranes for CO2 separation.
The first part of this dissertation describes the synthesis of polystyrene (PS) nanolayers by surface-initiated ATRP at …

Go to article

High-Rate Channel Catfish Fingerling Production In The Partitioned Aquaculture System, Tim Wells May 2009

High-Rate Channel Catfish Fingerling Production In The Partitioned Aquaculture System, Tim Wells

All Theses

The objective of this 4-year research project was to evaluate the performance of channel catfish (Ictalurus punctatus) fingerling production in the Partitioned Aquaculture System (PAS). The goal was to demonstrate production of 80-gram minimum sized fingerlings in a single growing season, allowing for 100% market-size fish production after one additional season in the grow-out PAS.
A series of 2-inch airlift pumps fed by a single 3-hp low-head blower was found to be capable of supplying sufficient water flow-rate (in 2005, 2006, and 2007) of gpm per container to 9 cohorts. A series of 0.75-hp axial flow pumps (in 2005, 2006, …

Go to article

Reliability Of Light Frame Roof Systems Subject To High Winds, Angelina Gleason May 2009

Reliability Of Light Frame Roof Systems Subject To High Winds, Angelina Gleason

All Theses

Recent hurricane damages have devastated coastal communities and focused national attention on hurricane damage mitigation. Structural damage is one of the most significant impacts of a hurricane. Even small levels of structural damage can result in large economic losses; when gaps open in the roof system, rain water can leak in, ruining the contents of the structure and rendering it uninhabitable although it is still standing. In order to prevent these secondary damages from occurring, a better understanding of the roof system behavior is essential. This research aims to ascertain the behavior of the roof system by determining the influence …

Go to article

A Tissue Engineering Approach To Anterior Cruciate Ligament, Kristofer Sinclair May 2009

A Tissue Engineering Approach To Anterior Cruciate Ligament, Kristofer Sinclair

All Dissertations

Ruptures of the anterior cruciate ligament (ACL) are the most frequent of injuries to the knee due to its role in preventing anterior translation of the tibia. It is estimated that as many as 200,000 Americans per year will suffer from a ruptured ACL, resulting in management costs on the order of 5 billion dollars. Without treatment these patients are unable to return to normal activity, as a consequence of the joint instability found within the ACL deficient knee.
Over the last thirty years, a variety of non-degradable, synthetic fibers have been evaluated for their use in ACL reconstruction; however, …

Go to article

Development Of Strategies For Enhanced In Situ Bioremediation Of High Concentrations Of Halogenated Methanes, Huifeng Shan May 2009

Development Of Strategies For Enhanced In Situ Bioremediation Of High Concentrations Of Halogenated Methanes, Huifeng Shan

All Dissertations

ABSTRACT
Bioremediation of high concentrations of halomethanes e.g., carbon tetrachloride (CT), trichlorofluoromethane (CFC-11) and chloroform (CF) has seldom been addressed before and remains highly challenging. A microcosm study was conducted to investigate bioremediation strategies for groundwater contaminated with CT (6 to 10 mg/L), CFC-11 (1 to 26 mg/L), CF (3-500 mg/L), and 1,1-dichloroethene (1,1-DCE; up to 9 mg/L) at a former industrial site in California. Biostimulation with corn syrup and catalytic amounts of vitamin B12 was demonstrated as a feasible remedial strategy and bioaugmentation with B12 represents the most promising bioremediation method of the ones studied. Halomethane transformation …

Go to article

Characterizing Liquefaction Resistance Of Aged Sand Deposits, Hossein Hayati May 2009

Characterizing Liquefaction Resistance Of Aged Sand Deposits, Hossein Hayati

All Dissertations

Presented in this dissertation are the results of various studies conducted to characterize the liquefaction resistance of aged natural deposits. The data considered include laboratory and field test results from sites in five countries with particular focus on multiple locations in the South Carolina Coastal Plain.
A new liquefaction potential map of the peninsula of Charleston, South Carolina, is presented. Liquefaction potential is expressed in terms of the liquefaction potential index (LPI) developed by Iwasaki et al. and calculated using 44 cone penetration test (CPT) profiles. The CPT profiles are supplemented with information from the 1:24,000 scale geologic map by …

Go to article

An Examination Of Confined Aquifer Gradient Behavior Under Pumping Conditions, Stefanie Fountain May 2009

An Examination Of Confined Aquifer Gradient Behavior Under Pumping Conditions, Stefanie Fountain

All Dissertations

Accurate and reliable estimates of groundwater flow and contaminant transport models are dependent on an understanding of the aquifer properties used to create the models. The borehole flowmeter has been used with increasing frequency at a variety of sites to produce high resolution vertical hydraulic conductivity (K(z)) distributions [Boggs et al. 1990; Rehfeldt et al. 1989b; Molz et al. 1989, Boman et al. 1997; Dinwiddie et al. 1999]. In theory, the validity of measurements obtained using borehole flowmeters is contingent on the hydraulic head gradients near the well at each discrete depth resulting from the pumping-induced flow having reached quasi-steady-state. …

Go to article

First Prev Next Last