Engineering Commons^™

Development Of A Design Enabler Tool For Frame Analysis For A Small Enterprise: A Case Study, Madhusudan Kayyar

All Theses

This case study investigates the design process followed by a small to medium scale enterprise (SME) that primarily depends on special expertise in the form of a few key individuals. These individuals design products mainly based on past experience, augmented by trial and error. This is an inefficient, time consuming, and expensive way of designing products and evaluating their performance. This study critiques the different steps in the current design process, identifying areas of potential improvement and enhancement through application of formal design methods and innovative design enablers. The 'Design Enablers' are design tools that assist the designer at various …

Seismic Fragility Curves For A Typical Highway Bridge In Charleston, Sc Considering Soil-Structure Interaction And Liquefaction Effects, Matthew Bowers

All Theses

Evidence from historical earthquakes suggests that the vulnerability of highway bridges is significantly affected by large permanent ground deformations caused by liquefaction as well as soil-structure interaction (SSI). The vulnerability of a typical multi-span simply-supported (MSSS) concrete girder bridge found in Charleston, South Carolina, is evaluated with consideration for liquefaction and SSI effects. In general, existing bridges in this region were not originally designed with consideration for seismic events or liquefaction of underlying soils. Fragility curves that represent the probability of exceeding predefined performance levels of damage given an earthquake of a particular intensity are used to evaluate the effects …

Morphological Charts: A Systematic Exploration Of Qualitative Design Space, Gregory Smith

All Theses

A morphological chart is a tool that represents a large qualitative design space. These charts list the functions identified for the design problem, and the means (solutions) that can perform each function. Combining one means for each function will produce a potential integrated conceptual design solution. Repeating this process with every possible combination contained in the morphological chart will generate a long list of conceptual design solutions. Not all of these solutions will be practical, or even physically possible.
As it is difficult to analyze a long list of design solutions and as at present, there are no systematic design …

Techniques For Improving The Performance Of Coupled Oscillator Arrays, Venkatesh Seetharam

All Dissertations

Coupled oscillator arrays (COAs) have excellent synchronization properties that can be utilized to develop a low cost alternative to phased array systems for beam steering applications. The primary concerns in implementing the COA architecture are the sensitivity to cell-to-cell component variation and poor phase noise performance. Wide injection locking range oscillators reduce the sensitivity to component variation but degrade the array phase noise performance. The objective of this dissertation is to alleviate the concerns hindering the application of COAs by employing techniques to realize COAs with wide mutual injection locking ranges (MILR), improved phase noise characteristics and beam steering capabilities. …

Mixed Convective Heat Transfer And Evaporation At The Air-Water Interface, Prasad Gokhale

All Theses

Functional forms for mixed convective heat transfer and evaporation from an air-water interface were obtained. To obtain these functions, heat transfer and evaporation rates from the air-water interface of an evaporating body of water were quantified in a wind/water tunnel in the presence of an oleyl alcohol monolayer on the water surface. The Nusselt (Nu) and Sherwood (Sh) numbers, parameterizing the dimensionless heat and mass transfer respectively, for transport from the water bulk to air were expressed as functions of the air side Rayleigh (Ra) and Reynolds (Re) numbers. The Nu and Sh were calculated for a range of Ra …

Sediment Transport Upstream Of Orifices, David Powell

All Dissertations

Sediment transport upstream of orifices has not been studied outside the realm of the restoration of reservoir storage capacity. This experimental study used a large basin with a circular orifice outlet and a movable sand bed leveled with the invert of the orifice. Three sizes of non-cohesive, uniform sand were used with d₅₀ values of 0.29mm, 0.72mm, and 0.89mm. Bed profiles at equilibrium scour conditions were measured for three different head levels for each sediment size. The maximum scour depth, length, and scour width were related to the particle size and the available head. The longitudinal and lateral extents …

Multi-Objective Generation Scheduling With Hybrid Energy Resources, Manas Trivedi

All Dissertations

In economic dispatch (ED) of electric power generation, the committed generating units are scheduled to meet the load demand at minimum operating cost with satisfying all unit and system equality and inequality constraints. Generation of electricity from the fossil fuel releases several contaminants into the atmosphere. So the economic dispatch objective can no longer be considered alone due to the environmental concerns that arise from the emissions produced by fossil fueled electric power plants. This research is proposing the concept of environmental/economic generation scheduling with traditional and renewable energy sources. Environmental/economic dispatch (EED) is a multi-objective problem with conflicting objectives …

Investigation Into Mitigation Of Alkali-Silica Reaction Using Selected Scms In Presence Of Potassium Acetate Deicer, Jigar Desai

All Dissertations

Alkali-silica reaction (ASR) is one of the most recognized durability problems in concrete leading to premature deterioration of different types of concrete structures. Recent investigation into premature deterioration of airfield concrete pavements indicated the aggressive effects of alkali-acetate and alkali-formate based deicers on concrete containing marginal aggregates, in particular on their potential to induce ASR.. This dissertation presents the results and analysis from a research study conducted to evaluate the effectiveness of selected supplementary cementitious materials-SCMs (fly ash and slag) as ASR mitigation measures in presence of potassium acetate based deicer.
Five aggregates that encompass a range of mineralogies and …

A Comparative Fault Diagnosis Methodology Based On Time Series Analysis Of System's Signals, Hany Bassily

All Dissertations

The detection of system anomalies represents an important task in safety critical systems. Over the past two decades, advances in data manipulation techniques and sensor technology have contributed to the widespread application of signal processing concepts for fault diagnosis. However, the majority of these signal processing, or data driven, diagnostics do not possess the redundancy level exhibited in conventional model-based methods. Among signal processing methods, time series analysis is advantageous since it offers insight into the underlying dynamics and forecasts system behavior. Furthermore, the data driven method allows the depiction of system dynamics with an increased level of redundancy. This …

Ultrahydrophobic Surface Modification Of Polymeric Fibers And Inorganic Substrates, Karthik Ramaratnam

All Dissertations

The wettability of a solid surface is a very important property, and is governed by both the chemical composition and the geometrical microstructure of the surface. Wettability and repellency are important properties of solid surfaces from both fundamental and practical aspects. The wettability of the solid surface is a characteristic property of materials and strongly depends on both the surface energy and the surface roughness. These properties may be approached by mimicking hydrophobic structures created by nature on lotus leaf surface. The lotus effect is based on surface roughness caused by different microstructures together with the hydrophobic properties of the …

An Experimental And Numerical Study Of The Film Casting Process, Kenneth Aniunoh

All Dissertations

Film casting is a common industrial process used to produce polymeric films. During film casting, a polymer melt is extruded through a flat die before rapid cooling on a chill roll. The chill roll velocity is faster than the velocity at which the melt exits the die, thus the polymer melt is stretched and oriented in an extensional flow. The material properties and processing conditions have a significant impact on the process and the final thermal/mechanical properties of the film produced.
Optimization of industrial scale film casting processes is still greatly dependent on trial and error methods. Therefore, this work …

Effect Of Carbon Nanofibers On Microstructure And Properties Of Polymer Nanocomposites, Sungho Lee

All Dissertations

Nano-modifiers are typically three orders of magnitude smaller in size than their micro-counterparts. At this scale, interactions between matrix molecules and the nano-modifiers can lead to novel physical and chemical properties of the resulting nanocomposites. Carbon nanofibers (CNFs) are a class of nano-modifiers that has received significant attention recently because they have superior electrical conductivity and mechanical properties with a high aspect ratio (length over diameter). Several recent research studies have focused on enhancing electrical and mechanical performance of composites in the presence of CNFs. However, the influence of CNFs on the structure of the polymer matrix is important in …

Investigation Of Structure And Properties Of Novel Multi-Layer Clay Nanocomposite Films Produced Controllably By Continuous Chaotic Advection Blending, Chaitra Mahesha

All Dissertations

Polymer nanoclay composites have been studied extensively in the past decade due to the excellent combination of properties they can offer at low loadings of clay. Despite robust research, the potential enhancements that nanoclays are theoretically predicted to offer have not been achieved. Such potential improvements in mechanical and gas barrier properties are realized only when the internal structure of the nanocomposite is optimized in terms of arrangement and orientation of nanoclay within the matrix. The mixing-based approach and the accompanying complex flow fields of conventional processing techniques widely used to produce nanoclay composites are unable to control the internal …

Development Of An In Vitro Test System For Breast Cancer Research, Chih-Chao Yang

All Dissertations

In the United States, breast cancer is the third most common cause of cancer death (after lung cancer and colon cancer). In 2007, breast cancer is expected to cause 40,910 deaths (7% of cancer deaths; almost 2% of all deaths) in the U.S. The long term goal of this project is to develop an in vitro test system that can be used to develop breast cancer vaccine or screen breast cancer chemotherapy. This dissertation was driven by four objectives and it can be thought as a toolbox that provides practical experimental design and lab work for the development of an …

A Pilot Study On The Effects Of Temperature On The Material Properties Of Prestressed Concrete And The Use Of Thermogravimetric Analysis In The Assessment Of Heat-Affected Concrete, Kacie Caple

All Theses

An understanding of the material property changes in building materials due to exposure to a fire is needed for accurate damage assessment of a structure. Discussion pertaining to material property changes and the bond between concrete and prestressing steel following elevated temperature exposures is presented. Evaluation of the use of thermogravimetric analysis (TGA) as a post-fire analysis tool to determine the maximum temperature exposure of concrete is also included.
Heated concrete cylinders were tested to determine the compressive strength and modulus of elasticity changes of concrete. Heated steel prestressing strands were tested in tension to determine changes in the ultimate …

Experimental And Analytical Application Of The Hodd Method For The Detection Of Damage, Jacob Merkley

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Detecting damage location and severity in civil engineering structures has become an important research topic in the past several decades. Various non-destructive damage identification methods using dynamic properties from ambient and forced vibration have been developed. Researchers have shown that higher order derivatives of mode shapes of the 2nd and 4th order can be effective in detecting damage in civil engineering structures. Furthermore, these higher order derivatives are sensitive to small changes in global stiffness facilitating the detection of small degrees of damage.
In this study a modal analysis is performed on analytical and experimental simply supported beams using the …

Formulation Of Integral Equations Using Analytic Green's Functions In Elliptic Cylindrical And Prolate Spheroidal Coordinates, Adam Schreiber

All Theses

It is desired to develop and present techniques, using analytic Green's functions in elliptic cylindrical coordinates and in prolate spheroidal coordinates, for formulating integral equations for physically practicable structures and sources. Equivalent models for two structures are introduced which serve as guides in the derivation of analytic Greens functions, comprising special functions and satisfying required boundary conditions. Expressions for needed field components are represented in terms of integrals of Greens functions times unknowns, and integral equations follow from the proper relationships among sources and field components needed to satisfy Maxwell's equations.

Adipocyte Response To Injectable Beads Engineered For Breast Tissue Reconstruction, Katherine Neser

All Theses

It is estimated that over 150,000 patients will be diagnosed with invasive breast cancer in 2007. Patients must undergo a mastectomy or a lumpectomy to remove the cancerous tissue, but only a mastectomy allows breast reconstructive surgery. Due to the limitations of current reconstruction options, new alternatives are being explored. Injectable materials have been suggested for breast tissue reconstruction because of their versatility. Cells cultured on injectable beads form cell carriers that may be mixed with a hydrogel, resulting in a construct that may be injected through a syringe to restore normal tissue mass. This solution offers breast cancer patients …

Glycosaminoglycan Stabilization In Bovine Pericardium, Lauren Browne

All Theses

Glutaraldehyde crosslinked bovine pericardium has been used for fabrication of bioprosthetic heart valves as well as cardiac patches for soft tissue repair. However, calcification and limited mechanical stability result in shortened life for the prostheses. Previous research has shown that glutaraldehyde crosslinking does not stabilize glycosaminoglycans (GAGs) and that GAGs are lost from porcine bioprosthetic heart valves[1]. Bovine pericardial tissue is composed of an amorphous network of collagen and elastin fibers, proteoglycans, and GAGs. The GAGs of bovine pericardium include dermatan sulfate, chondroitin sulfate, and hyaluronan [2].
It is hypothesized that Glut does not stabilize GAGs in pericardium and loss …

Biohydrogen Production By The Hyperthermophilic Bacterium Thermotoga Neapolitana, Xiaohui Yu

All Dissertations

ABSTRACT Thermotoga neapolitana can use different sources of carbon and nitrogen for growth and produces biological hydrogen. Sources of carbon (glucose, sucrose, xylose, xylan, cellulose, cellobiose, starch, corn starch, beet bulp pellet, and rice flour) and nitrogen (yeast extract, fish meal, cottonseed meal, canola meal, linseed meal, and soybean meal) were compared. In the carbon studies, glucose, sucrose, rice flour, and xylan produced similar levels of hydrogen. In the nitrogen studies, Trypticase combined with alternative nitrogen sources can efficiently increases the yield of hydrogen produced by Thermotoga neapolitana. Yeast extract with trypticase as the dual nitrogen sources produced significantly increased …

Load Shedding Algorithm Using Voltage And Frequency Data, Poonam Joshi

All Theses

Under frequency load shedding schemes have been widely used, to restore power system stability post major disturbances. However, the analysis of recent blackouts suggests that voltage collapse and voltage-related problems are also important concerns in maintaining system stability. For this reason, both frequency and voltage need to be taken into account in load shedding schemes. The research undertaken here considers both parameters in designing a load shedding scheme to determine the amount of load to be shed and its appropriate location. An introduction about the need for a load shedding scheme and the purpose of doing research on this particular …

Design Of Alu And Cache Memory For An 8 Bit Alu, Pravin Chander Chandran

All Theses

The design of an ALU and a Cache memory for use in a high performance processor was examined in this thesis. Advanced architectures employing increased parallelism were analyzed to minimize the number of execution cycles needed for 8 bit integer arithmetic operations. In addition to the arithmetic unit, an optimized SRAM memory cell was designed to be used as cache memory and as fast Look Up Table.
The ALU consists of stand alone units for bit parallel computation of basic integer arithmetic operations. Addition and subtraction were performed using Kogge Stone parallel prefix hardware operating at 330MHz. A high performance …

Performance Based Contracting And Improving The Current Contracting Process, Troy Berkland

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The primary objective of the research described in this report was to suggest improvements to the maintenance contracting process currently utilized by the South Carolina Department of Transportation (SCDOT). A secondary research objective was to examine to what extent SCDOT could migrate more toward performance based, as opposed to method based, highway maintenance specifications.
A comprehensive literature review indicated some states had successfully implemented performance based specifications for a wide range of maintenance activities whereas others had not. Some states have adopted performance based specifications as part of a comprehensive asset management program whereby the contractor typically performs all routine …

Quality And Inspection Of Machining Operations: Review Of Condition Monitoring And Cmm Inspection Techniques 2000 To Present, John T. Roth, Laine Mears, Dragan Djurdjanovic, Xiaping Yang, Thomas Kurfess

Publications

In order to consistently produce quality parts, many aspects of the manufacturing process must be carefully monitored, controlled, and measured. The methods and techniques by which to accomplish these tasks has been the focus of numerous studies in recent years. With the rapid advances in computing technology, the complexity and overhead that can be feasibly incorporated in any developed technique has dramatically improved. Thus, techniques that would have been impractical for implementation just a few years ago can now be realistically applied.

This rapid growth has resulted in a wealth of new capabilities for improving part and process quality and …

Achiral And Chiral Analysis Of Polychlorinated Biphenyls (Pcbs) In The Aquatic And Riparian Food Webs In Twelve Mile Creek, South Carolina., Viet Dang

All Theses

Polychlorinated biphenyls (PCBs) contamination in the Twelve Mile Creek arm of Lake Hartwell, South Carolina, has been an issue for decades. Lake Hartwell, which is a reservoir located on the border between the states of South Carolina and Georgia, was contaminated with an estimated 440,000 pounds of PCBs. PCBs were released from the Sangamo-Weston capacitor plant located on Town Creek, which feeds into Twelve Mile Creek and ultimately Lake Hartwell. The Twelve Mile Creek tributary connecting the Sangamo-Weston plant to Lake Hartwell has had little attention. Understanding PCBs contamination in the aquatic and riparian food webs of Twelve Mile Creek …

Exact Solution Of Time History Response For Dynamic Systems With Coupled Damping Using Complex Mode Superposition, Manoj Kumar Chinnakonda

All Theses

An exact solution method for general, non-proportional damping time history response for piece-wise linear loading proposed by Dickens is generalized to piece-wise quadratic loading. Comparisons are made to Trapezoidal and Simpson's quadrature rules for approximating the time integral of the weighted generalized forcing function in the exact solution to the decoupled modal equations arising from state-space modal analysis of linear dynamic systems. The time integral of the forcing function is recognized as a weighted integral with complex exponential and the general update formulas are derived using polynomial interpolation to the forcing function. Closed-form expressions for the weighting parameters in the …

Assessment Of Driver Speeds, Compliance In Rural School Zones: Comparison Of Speed By School Level And Time Of Day, Stuart Day

All Theses

TThis study analyzed driver's speeds prior to entering school zones as well as the speeds traveling through school zones. A comparison was conducted to determine if drivers complied with school speed zones using only the standard school sign arrangement found in the Manual on Uniform Traffic Control Device. Two rural school zones in Oconee County, South Carolina were analyzed in this study as rural areas tend to have higher speeds and fewer other factors that could contribute to changes in driver behavior. In order to gather data, data collection devices known as Hi-Stars were placed in the roadway on both …

Enterprise Security Analysis Including Denial Of Service Countermeasures, Chinar Dingankar

All Theses

Computer networks are the nerve systems of modern enterprises. Unfortunately, these networks are subject to numerous attacks. Safeguarding these systems is challenging. In this thesis we describe current threats to enterprise security, before concentrating on the Distributed denial of Service (DDoS) problem.
DDoS attacks on popular websites like Amazon, Yahoo, CNN, eBay, Buy, and the recent acts of war using DDoS attacks against NATO ally Estonia [1] graphically illustrate the seriousness of these attacks. Denial of Service (DoS) attacks are explicit attempts to block legitimate users' system access by reducing system availability [2]. A DDoS attack deploys multiple attacking entities …

Steer It And Clear It: Effectiveness Of Quick Clearance Legislation, Amy Carol Hamlin

All Theses

Innovative incident management strategies have been sought by transportation professionals to minimize the impacts of incidents on traffic operation and safety. Some current quick clearance strategies such as 'Steer It and Clear It' legislation in South Carolina, which requires driver(s) of involved vehicle(s) in a minor incident to move vehicles promptly from the traveled roadway prior to the arrival of the first responders, can potentially reduce the duration of an incident. The research detailed in this paper endeavored to measure the benefit of the Steer It and Clear It law on a section of I-85 in South Carolina. A simulation …

Improving The Performance Of Software Defined Radio By Employing Digital Feedback Of Radio Frequency Properties, Joel Simoneau

All Dissertations

This dissertation provides tools for the analysis and integration of the hardware and software components of a software defined radio for optimum radio frequency performance. A device is introduced that is able to give baseband feedback of radio frequency properties suitable for analysis in software. Three applications for the device are devised. The first is an image rejection upconverter that achieves greater than 65 dB of image rejection over a broad frequency range without the use of a radio frequency filter. The second application is a baseband correction scheme for extending the bandwidth and improving the magnitude and phase match …