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 2101 - 2130 of 2584

Full-Text Articles in Engineering

Occurrence And Formation Of Disinfection By-Products In Indoor Swimming Pools Water, Amer Kanan May 2010

Occurrence And Formation Of Disinfection By-Products In Indoor Swimming Pools Water, Amer Kanan

All Dissertations

Chlorination is used to prevent the spread of waterborne infectious diseases from swimming pools. This required disinfection practice also results in the formation of undesirable disinfection by-products (DBPs) from the reactions of chlorine with the organic matter (released by swimmers or present in the filling water of the pool) and bromide. Some of these DBPs have important adverse public health effects; as a result their concentrations in drinking waters are regulated. Unfortunately, DBPs formation and control in swimming pools have not been studied and investigated to the same extent as their formation and control in drinking water.
The main objective …

Go to article

Layer-By-Layer Assembly Of {Nanoclay-(Sol-Gel Oxide)}N And {Nanoclay-(Oxide Nanoparticle)}N Multilayers: Synthesis And Growth Mechanisms, Hao Chen May 2010

Layer-By-Layer Assembly Of {Nanoclay-(Sol-Gel Oxide)}N And {Nanoclay-(Oxide Nanoparticle)}N Multilayers: Synthesis And Growth Mechanisms, Hao Chen

All Dissertations

Two new classes of all-inorganic nanostructured multilayers, {MMTx-(sol-gel oxide)}n and {MMTx-(oxide nanoparticle)}n, have been successfully synthesized for the first time. They were made by adapting a layer-by-layer (LbL) assembly method initially developed to synthesize polyelectrolyte-based multilayers. In most previous studies, this electrostatic-assisted LbL assembly method used polyelectrolytes/polymers as the 'structural glue' to prepare multilayers. The synthesis of {MMTx-(sol-gel ZrO2)}n multilayers demonstrates for the first time the feasibility of making sol-gel oxide 'glued' all-inorganic multilayers, thereby introducing an innovative nanoscale fabrication concept. The synthesis of {MMTx-(oxide nanoparticle)}n multilayers further illustrates the versatility of LbL assembly technique by achieving a second new …

Go to article

Osteoclast-Mediated Cell Therapy As An Attempt To Treat Elastin-Specific Vascular Calcification, Chartrisa Simpson May 2010

Osteoclast-Mediated Cell Therapy As An Attempt To Treat Elastin-Specific Vascular Calcification, Chartrisa Simpson

All Dissertations

Vascular calcification occurs during physiological aging and is clinically recognized as a major risk factor for myocardial infarction, systolic hypertension, heart failure and coronary insufficiency caused by loss of aortic recoil. Medial arterial calcification is an active remodeling process that involves the deposition of bone-specific matrix in close association with elastic fibers. Elastin, a major structural protein in the extracellular matrix of arterial walls, provides elastic recoil to the arteries. Increasing evidence suggests that vascular calcification share features with skeletal bone formation such as bone matrix deposition and bone resorption. Bone morphogenetic proteins and bone cells have been found in …

Go to article

Isolating Petroleum Pitch Oligomers Via Multistage Supercritical Extraction, Eduardo Cervo May 2010

Isolating Petroleum Pitch Oligomers Via Multistage Supercritical Extraction, Eduardo Cervo

All Dissertations

Petroleum pitches are carbonaceous materials that serve as precursors for advanced carbon products. Because of their highly graphitic nature, such pitches are of particular interest for producing high thermal conductivity carbon fibers for thermal management applications, such as microelectronics packaging for hybrid and plug-in vehicles.
Even though the properties of the final carbon products are impacted by the molecular composition of the starting pitch precursor, a fundamental understanding of this relationship has yet to be established. To this end, dense-gas extraction (DGE), a fractionation technique that allows for the production of pitches of controlled composition for both analytical and rheological …

Go to article

Effect Of Machining Feed On Surface Roughness In Cutting 6061 Aluminum, Mathew Kuttolamadom, Sina Hamzehlouia, Laine Mears Apr 2010

Effect Of Machining Feed On Surface Roughness In Cutting 6061 Aluminum, Mathew Kuttolamadom, Sina Hamzehlouia, Laine Mears

Publications

The general manufacturing objective during the fabrication of automotive components, particularly through machining, can be stated as the striving to achieve predefined product quality characteristics within equipment, cost and time constraints. The current state of the economy and the consequent market pressure has forced vehicle manufacturers to simultaneously reduce operating expenses along with further improving product quality. This paper examines the achievability of surface roughness specifications within efforts to reduce automotive component manufacture cycle time, particularly by changing cutting feeds. First, the background and attractiveness of aluminum as a lightweight automotive material is discussed. Following this, the methodologies employed for …

Go to article

Investigation Of The Machining Of Titanium Components For Lightweight Vehicles, Laine Mears, Mathew A. Kuttolamadom, Joshua J. Jones, Thomas R. Kurfess, Aditya S. Choragudi Jan 2010

Investigation Of The Machining Of Titanium Components For Lightweight Vehicles, Laine Mears, Mathew A. Kuttolamadom, Joshua J. Jones, Thomas R. Kurfess, Aditya S. Choragudi

Publications

Due to titanium’s excellent strength-to-weight ratio and high corrosion resistance, titanium and its alloys have great potential to reduce energy usage in vehicles through a reduction in vehicle mass. The mass of a road vehicle is directly related to its energy consumption through inertial requirements and tire rolling resistance losses. However, when considering the manufacture of titanium automotive components, the machinability is poor, thus increasing processing cost through a trade-off between extended cycle time (labor cost) or increased tool wear (tooling cost). This fact has classified titanium as a “difficult-to-machine” material and consequently, titanium has been traditionally used for application …

Go to article

Influence Of Shear Key Performance On The Fatigue Life Of Adjacent Beam Bridges, Sara Roberts Jan 2010

Influence Of Shear Key Performance On The Fatigue Life Of Adjacent Beam Bridges, Sara Roberts

All Theses

Adjacent beam bridges, such as box beams and hollow core bridges have been one of the most popular forms of precast prestressed bridges in the past. Recently, an awareness of major durability problems has led owners to make improvements to the old standards or move away from the system completely. These issues usually stem from the breakdown of the shear key which provides continuity between adjacent members. This research focuses on determining the best improvements that will reduce durability issues and increase the bridge's service life.
A review of previous research performed on adjacent beam bridges is performed, focusing on …

Go to article

The Characterization Of Leadership Within Undergraduate Engineering Design Teams Through Case Study Analysis, Gary Palmer Ii Jan 2010

The Characterization Of Leadership Within Undergraduate Engineering Design Teams Through Case Study Analysis, Gary Palmer Ii

All Theses

The purpose of this research is to clearly define leadership that exists within engineering project teams. Leadership can be applicable to any field of study and is heavily researched in business management. Sources which review leadership classify this topic in reference to managerial styles, leadership types and styles, emotional intelligence, and work climate. However, there are few sources which define leadership specifically within engineering environments. The motivation of this research is driven by the absence of defining and observing consistency in engineering leadership through the research‟s experience in engineering teams. Existing leadership is defined in this research through conducting two …

Go to article

Investigation Of The Thermoelectric Behavior Of Cu-Doped Pbteagxse, Ben Ma Jan 2010

Investigation Of The Thermoelectric Behavior Of Cu-Doped Pbteagxse, Ben Ma

All Theses

Sustainable energy research is currently on the forefront of scientific exploration thus a major effort is devoted to the development of new energy conservation and production techniques. Thermoelectric materials can play a significant part both in energy conservation and energy production via the Seebeck effect (heat to electric power) and the Peltier effect (electricity to cooling power), since they can convert wasted heat to useful electrical energy.
Presented herein are the measured electrical and thermal transport properties and phenomenal analysis of the PbTeAgxSe (x=1.9, 2.0, 2.01) system. First, it would lead to a significant reduction in the thermal conductivity and …

Go to article

Production And Characterization Of Novel Air Filtration Media, Elizabeth Skomra Jan 2010

Production And Characterization Of Novel Air Filtration Media, Elizabeth Skomra

All Dissertations

HEPA and ULPA filtration systems have proven to be an advantageous instrument in removing common contaminants from the air. However, an increased pressure drop due to the build-up of particulates on the filters results in its inevitable decrease in performance. Improving current filtration systems would include increasing collection efficiency all the while either maintaining or reducing the differential pressure drop in order to extend the life of the filter. One method of improving collection efficiency would be viable by increasing the amount of surface area within the filter media by glass fibers because of their inherent quality of being smaller …

Go to article

The Development Of A Mesenchymal Stem Cell Based Biphasic Osteochondral Tissue Engineered Construct, Scott Maxson Jan 2010

The Development Of A Mesenchymal Stem Cell Based Biphasic Osteochondral Tissue Engineered Construct, Scott Maxson

All Dissertations

The ability of human articular cartilage to respond to injury is poor. Once cartilage damage has occurred, an irreversible degenerative process can occur and will often lead to osteoarthritis (OA). An estimated 26.9 million of U.S. adults are affected by OA. Osteochondral grafting is currently used to treat OA and osteochondral defects; however, complications can develop at the donor site and defect area. Osteochondral tissue engineering provides a potential treatment option and alternative to osteochondral grafting. The long term goal of this work is to develop a tissue engineered mesenchymal stem cell (MSC) based osteochondral construct to repair cartilage damage. …

Go to article

Analysis Of Factors Contributing To Roadside Tree Crashes In South Carolina, Vijay Bendigeri Dec 2009

Analysis Of Factors Contributing To Roadside Tree Crashes In South Carolina, Vijay Bendigeri

All Theses

The state of South Carolina has experienced a large number of fatalities and injuries resulting from run off the road tree related crashes. According to 2008 FARS data tree related fixed object fatal crashes in South Carolina (65%) are more than double that of the national (25.8%). Thus, trees are much bigger proportion of all roadside hazards in South Carolina than nationally. In order to achieve a safer roadside which is favorable to the road user, factors contributing to the tree related crashes should be critically analyzed to determine suitable safety improvements.
This research aims at qualitatively and quantitatively assessing …

Go to article

The Effect Of A Surfactant Monolayer On Gas Exchange Across An Air-Water Interface During Mixed Convection, Richard Lee Dec 2009

The Effect Of A Surfactant Monolayer On Gas Exchange Across An Air-Water Interface During Mixed Convection, Richard Lee

All Theses

A set of laboratory experiments are presented that reveal the effect of a surfactant monolayer on the transport of oxygen across an air-water interface during mixed convection conditions. The experiments were conducted in a wind/water tunnel with water tanks of differing depth. Forced convection was imposed via the air flow, while natural convection was imposed by heating the water bulk above the air temperature. For the range of wind speeds being considered, mixed convection conditions resulted. Experiments were also conducted with only forced convection present. The data acquired during these experiments were used to develop a parameterization between the Sherwood …

Go to article

Effectiveness Of Team-Building And Teamwork In Real And Virtual Worlds, Rachana Ranade Dec 2009

Effectiveness Of Team-Building And Teamwork In Real And Virtual Worlds, Rachana Ranade

All Theses

Given the increasing importance of globalization and collaboration, this research investigates the possibility of performing team-building training for globally dispersed teams using the capabilities of the virtual world Second Life. Three meeting conditions, the 3D virtual world Second Life, a combination of face-to-face and Second Life and face-to-face were evaluated. Thirty randomly assigned 3 person teams performed an ice-breaker session and then a team-building activity in each meeting condition. Four dependent variables were measured: task completion time; quality of task performance; the subjective satisfaction with the process based on group cohesiveness, perception of the process and satisfaction with the outcome; …

Go to article

Modeling The Cooling Phase Of The Lens Molding Process, Saravanan Kannan Dec 2009

Modeling The Cooling Phase Of The Lens Molding Process, Saravanan Kannan

All Theses

The lens molding process is a relatively new technique used to manufacture lenses, in particular, high precision aspheric lenses. In order to achieve the desired size and shape of the lens, the cooling process after pressing must be controlled precisely because of the time and temperature dependent viscoelastic behavior of glass near and below the molding temperature. This thesis gives a detailed description of a three-dimensional computational model for analyzing the cooling phase of the lens molding process. Conduction, convection and radiation are considered in the model by coupling a computational fluid dynamics analysis of the flow of nitrogen through …

Go to article

A Logistic Regression Model To Predict Incident Severity Using The Human Factors Analysis And Classification System, Hrishikesh Kavade Dec 2009

A Logistic Regression Model To Predict Incident Severity Using The Human Factors Analysis And Classification System, Hrishikesh Kavade

All Theses

The Human Factors Analysis and Classification System (HFACS) is used to help identify causal factors that lead to human error. The framework has been used in a variety of industries to identify leading contributing factors of unsafe events, such as accidents, incidents and near misses. While traditional application of the HFACS framework to safety outcomes has allowed evaluators to identify leading causal issues based on frequency, little has been done to gain a more comprehensive view of the system's total risk. This work utilizes the concept of event severity along with the HFACS framework to help better identify target areas …

Go to article

Analysis Of Distributed Denial Of Service Attacks And Countermeasures, Sampada Karandikar Dec 2009

Analysis Of Distributed Denial Of Service Attacks And Countermeasures, Sampada Karandikar

All Theses

Network technology has experienced explosive growth in the past two decades. The vast connectivity of networks all over the world poses monumental risks. The generally accepted philosophy in the security world is that no system or network is completely secure [1] which makes network security a critical concern. The work done in this thesis focuses on Distributed Denial of Service Attacks (DDoS) where legitimate users are prevented from accessing network services. Although a lot of research has been done in this field, these attacks remain one of the most common threats affecting network performance.
One defense against DDoS attacks is …

Go to article

Thermoelastic Behavior Of A Small Bearing Cage, Eric Planting Dec 2009

Thermoelastic Behavior Of A Small Bearing Cage, Eric Planting

All Theses

The full field non contact measurement of objects undergoing testing is one of interest for manufacturers of parts which are graded on their longevity. Unfortunately, for homogenous small parts with irregular geometries, such as bearing cages, the solution for testing is typically to use only a FEA model and compliment the testing of the model with simply cyclically loading the sample until failure. To better understand the stresses and behavior of a small object Thermoelasticity can be employed in order to see in a full field technique what stress patterns exist and their correlation to a FEA model.
The FEA …

Go to article

Performance Of Storm Water Stage And Quality Measuring Instruemtnation Of A Small Watershed Using A Remote Monitoring Station, Rebecca Crane Dec 2009

Performance Of Storm Water Stage And Quality Measuring Instruemtnation Of A Small Watershed Using A Remote Monitoring Station, Rebecca Crane

All Theses

ABSTRACT


As economic development proceeds special care must be taken to preserve and sustain our water resources. Monitoring the storm water from a watershed during a rainfall event can help quantify any changes in water quantity and quality. An accurate means of measuring flow is necessary for all watershed monitoring projects. This study was conducted to analyze the performance of stage, turbidity, and temperature measuring devices in a laboratory setting as well as on Honeycutt Creek in Clemson, South Carolina.
The stage measuring devices under study include: a radar level sensor, ultrasonic transmitter, pressure transducer, and a bubbler module. A …

Go to article

Laboratory Generation And Physics Of Propagation Of Solitary Waves And Water Surface Depressions, Siamak Malek Mohammadi Dec 2009

Laboratory Generation And Physics Of Propagation Of Solitary Waves And Water Surface Depressions, Siamak Malek Mohammadi

All Dissertations

Solitary waves and water surface depressions are generated using a piston-type wavemaker. Different aspects of their propagation including profile evolution, establishment rate, stability, and celerity are examined experimentally.
Traditionally, solitary waves are generated in laboratory set-ups using a methodology developed by Goring (1979) that considers a wave of permanent form during the generation process. A New methodology for generation of solitary waves using piston-type wavemakers is proposed by considering the evolving nature of the wave during generation phase. The capability of the New methodology in generation of solitary waves is assessed by conducting a series of laboratory experiments in water …

Go to article

A Particle Swarm Optimization Using Random Keys For Flexible Flow Shop Scheduling Problem With Sequence Dependent Setup Times, Vinodh Sankaran Dec 2009

A Particle Swarm Optimization Using Random Keys For Flexible Flow Shop Scheduling Problem With Sequence Dependent Setup Times, Vinodh Sankaran

All Theses

In this research, a particle swarm optimization algorithm (PSO) using random keys is developed to schedule flexible flow lines with sequence dependent setup times to minimize makespan. The flexible flow line scheduling problem is a branch of production scheduling and is found in industries such as printed circuit board and automobile manufacturing. It is well known that this problem is NP-hard. For this reason, we approach the problem by implementing a particle swarm optimization (PSO), a metaheuristic which is inspired by the motion of a flock of birds or a school of fish searching for food. The proposed PSO has …

Go to article

Vibrations Of Thin Plate With Piezoelectric Actuator: Theory And Experiments, Parikshit Mehta Dec 2009

Vibrations Of Thin Plate With Piezoelectric Actuator: Theory And Experiments, Parikshit Mehta

All Theses

Vibrations of flexible structures have been an important engineering study owing to its both deprecating and complimentary traits. These flexible structures are generally modeled as strings, bars, shafts and beams (one dimensional), membranes and plate (two dimensional) or shell (three dimensional). Structures in many engineering applications, such as building floors, aircraft wings, automobile hoods or pressure vessel end-caps, can be modeled as plates. Undesirable vibrations of any of these engineering structures can lead to catastrophic results. It is important to know the fundamental frequencies of these structures in response to simple or complex excitations or boundary conditions.
After their discovery …

Go to article

User Study Of Information Extracted From Engineering Representations, Rachel Hannah Dec 2009

User Study Of Information Extracted From Engineering Representations, Rachel Hannah

All Theses

It is important for designers to understand the usefulness of different engineering representations in order to save time and money throughout a project. Designers often rely on past experience to decide which model to construct; yet students without this experience have no help. Interestingly there are noticeable gaps in the research literature with respect to how and when to select representations and modeling approaches for engineering designs. This thesis examines the differences between three types of engineering representations, specifically sketches, drawing packages, and physical prototypes. The amount of information designers can extract from these representations and also the correctness and …

Go to article

Sensor-Based Soil Water Monitoring To More Effectively Manage Agricultural Water Resources In Coastal Plain Soils, Christopher Bellamy Dec 2009

Sensor-Based Soil Water Monitoring To More Effectively Manage Agricultural Water Resources In Coastal Plain Soils, Christopher Bellamy

All Theses

Cotton (Gossypium hirsutum L.) is widely grown in the United States with 5.7 million ha grown nationally and 1.2 million ha grown in the humid southeastern states in 2005. From 1969 to 2003, agricultural irrigated farmland acreage and total water applied increased by over 40% and 11% respectively to include a total of 55.3 million acres in 2002. Combined with recent and more frequent drought periods and legal water conflicts between states, there has been an increased interest in more effective southeastern water management, thus making the need to develop improved irrigation scheduling methods and enhanced water use efficiency of …

Go to article

The Rheology, Degradation, Processing, And Characterization Of Renewable Resource Polymers, Jason Conrad Dec 2009

The Rheology, Degradation, Processing, And Characterization Of Renewable Resource Polymers, Jason Conrad

All Dissertations

Renewable resource polymers have become an increasingly popular alternative to conventional fossil fuel based polymers over the past couple decades. The push by the government as well as both industrial and consumer markets to go 'green' has provided the drive for companies to research and develop new materials that are more environmentally friendly and which are derived from renewable materials. Two polymers that are currently being produced commercially are poly-lactic acid (PLA) and polyhydroxyalkanoate (PHA) copolymers, both of which can be derived from renewable feedstocks and have shown to exhibit similar properties to conventional materials such as polypropylene, polyethylene, polystyrene, …

Go to article

Voltage Stability Indices Based On Active Power Transfer Using Synchronized Phasor Measurements, Rui Sun Dec 2009

Voltage Stability Indices Based On Active Power Transfer Using Synchronized Phasor Measurements, Rui Sun

All Theses

In recent years and in the foreseeable future, power demands generally around the world and particularly in North America will experience rapid increases due to the increase of customers' requirements, while the development of transmission systems in North America is rather slow. Voltage stability assessment becomes one of the highest priorities to power utilities in North America. Voltage stability index is a feature for solving voltage stability problems. It is generated from the basic power flow equations and/or energy functions. The mathematical expression of a VSI is often written as a polynomial containing the systems real-time measurements such as voltage …

Go to article

Linguistic Analysis Of Natural Language Engineering Requirements, Carl Lamar Dec 2009

Linguistic Analysis Of Natural Language Engineering Requirements, Carl Lamar

All Theses

In engineering design, the needs of the customer are expressed through engineering requirement statements. These requirement statements are often expressed using natural language because they are easily created and read. However, there are several problems associated with natural language requirements including but not limited to ambiguity, incompleteness, understandability, testability and over specificity. Several representation and analysis tools have been proposed to address these problems within a requirement statement. These tools include formal languages, such as UML and SysML, requirement management tools, such as IBM Telelogic Doors, and natural language processors such as QuARS. These tools assist in the systematic elicitation …

Go to article

The Development Of A Mechatronics And Material Handling Course: Laboratory Experiments And Projects, James Shirley Dec 2009

The Development Of A Mechatronics And Material Handling Course: Laboratory Experiments And Projects, James Shirley

All Theses

Mechatronic systems integrate technologies from a variety of engineering disciplines to create solutions to challenging industrial problems. The material handling industry utilizes mechatronics to move, track, and manipulate items in factories and distribution centers. Material handling systems, because of their use of programmable logic controllers (PLC), PLC networks, industrial robotics, and other mechatronic elements, are a natural choice for a college instructional environment. This thesis offers insight and guidance for mechatronic activities introduced in a laboratory setting. A series of eight laboratory experiments have been created to introduce PLCs, robotics, electric circuits, and data acquisition fundamentals. In-depth case studies synthesize …

Go to article

A Voltage Flicker Suppression Device For Residential Air Conditioners And Heat Pumps, John Fox Dec 2009

A Voltage Flicker Suppression Device For Residential Air Conditioners And Heat Pumps, John Fox

All Theses

In some circumstances, voltage flicker due to the inrush current of residential heat pump can be a fairly visible to the residents as a slight flashing of the household's lights during the compressor starting event. The voltage flicker problem is caused by a variable contribution from sizable equivalent power system impedances and considerable inrush currents drawn by compressors. While this is not a new problem, and there are technologies on the market that attempt to alleviate the voltage flicker issue, no current solution attempts to correct for the problem at its root cause.
This thesis presents a device designed to …

Go to article

The Formation And Control Of Iodinated Trihalomethanes In Drinking Water Treatment, Darryl Jones Dec 2009

The Formation And Control Of Iodinated Trihalomethanes In Drinking Water Treatment, Darryl Jones

All Theses

Ever since toxic disinfection by-products (DBPs) were discovered in the 1970s drinking water utilities have had to continue to develop treatment strategies to reduce the acute health risk from infectious pathogens in water, and at the same time limit the formation of disinfection by-products. The recent two stage (1998, 2006) D/DBP rule enacted by the Environmental Protection Agency (EPA) which sets limits of 80 µg/L for trihalomethanes (THMs) and 60 µg/L for haloacetic acids (HAAs) will likely put more pressure on utilities in the future to decrease their chorine contact time and follow that with ammonia addition to form monochloramine …

Go to article

First Prev Next Last