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 1111 - 1140 of 2584

Full-Text Articles in Engineering

A Laminated Ring On Elastic Foundation Model With Application To Analysis Of Tire-Road Contact, Chunjian Wang Dec 2015

A Laminated Ring On Elastic Foundation Model With Application To Analysis Of Tire-Road Contact, Chunjian Wang

All Dissertations

A deformable Ring on Elastic Foundation (REF) model has been widely used for modeling rotating structures such as gears, bearings and tires. This dissertation extends the existing work with three main contributions focusing on applications to tires: 1) The elastic foundation is endowed with unilateral stiffness, which leads to a nonlinear deformation dependent stiffness typical of some non-pneumatic tires; 2) The model of the deformable ring is extended from simple Timoshenko rings to a laminated orthotropic ring model, with bending, shear stiffness and extensibility in the internal layer, and transverse stiffness in the external layer; 3) Facilitated by the laminated …


Synthesis And Characterization Of Oleophobic Fluorinated Polyester Films, Tugba Demir Dec 2015

Synthesis And Characterization Of Oleophobic Fluorinated Polyester Films, Tugba Demir

All Dissertations

The study presented in this dissertation is dedicated to the synthesis and characterization of oleophobic fluorinated polyester films. Specifically, the blending of oleophilic polyethylene terephthalate (PET) with low surface energy materials such as fluorinated polyesters has been used in order to fabricate oleophobic PET films. First, fluorinated polyesters (P(PF-oate-R)) possessing different end-groups (-COOH, -OH and -CF3) are synthesized via polycondensation reaction of isophthaloyl chloride with perfluoro ether alcohols. Then, they are solvent-blended with PET at various concentrations to obtain oleophobic polyester films of different compositions. In addition, the films are annealed to investigate the effect of annealing on surface properties …


Characterizing The Effective Bandwidth Of Nonlinear Vibratory Energy Harvesters Possessing Multiple Stable Equilibria, Meghashyam Panyam Mohan Ram Dec 2015

Characterizing The Effective Bandwidth Of Nonlinear Vibratory Energy Harvesters Possessing Multiple Stable Equilibria, Meghashyam Panyam Mohan Ram

All Dissertations

In the last few years, advances in micro-fabrication technologies have lead to the development of low-power electronic devices spanning critical fields related to sensing, data transmission, and medical implants. Unfortunately, effective utilization of these devices is currently hindered by their reliance on batteries. In many of these applications, batteries may not be a viable choice as they have a fixed storage capacity and need to be constantly replaced or recharged. In light of such challenges, several novel concepts for micro-power generation have been recently introduced to harness, otherwise, wasted ambient energy from the environment and maintain these low-power devices. Vibratory …


Integrated Coherent Combining Of Angled-Grating Broad-Area Lasers: Design, Fabrication And Characterization, Yunsong Zhao Dec 2015

Integrated Coherent Combining Of Angled-Grating Broad-Area Lasers: Design, Fabrication And Characterization, Yunsong Zhao

All Dissertations

In this thesis, we proposed, fabricated and demonstrated the coherent beam combining of angled-grating broad-area lasers. We have obtained the simultaneous coherent beam combining and single transverse mode operation completely on chip without any external phase control/components. Since the single transverse mode is the key to obtain diffraction-limit beam quality and high brightness, the proposed design is a good candidate for high power and high brightness applications. In the proposed coherently combined laser array, we use the angled-grating broad-area laser as the building block and overlap the adjacent emitters at one facet. The overlapped region becomes a 2D coupling region. …


A Time-Efficient Strategy For Relay Selection And Link Scheduling In Wireless Communication Networks, Chenxi Qiu Dec 2015

A Time-Efficient Strategy For Relay Selection And Link Scheduling In Wireless Communication Networks, Chenxi Qiu

All Dissertations

Despite the unprecedented success and proliferation of wireless communication, sustainable reliability and stability among wireless users are still considered important issues in the underlying link protocols. Existing link-layer protocols, like ARQ [44] or HARQ [57,67] approaches are designed to achieve this goal by discarding a corrupted packet at the receiver and performing one or more retransmissions until the packet is successfully decoded or a maximum number of retransmission attempts is reached. These strategies suffer from degradation of throughput and overall system instability since packets need to be en/decode in every hop, leading to high burden for relay nodes especially when …


A Special Protection Scheme Utilizing Trajectory Sensitivity Analysis In Power Transmission, Dan Suriyamongkol Dec 2015

A Special Protection Scheme Utilizing Trajectory Sensitivity Analysis In Power Transmission, Dan Suriyamongkol

All Dissertations

In recent years, new measurement techniques have provided opportunities to improve the North American Power System observability, control and protection. This dissertation discusses the formulation and design of a special protection scheme based on a novel utilization of trajectory sensitivity techniques with inputs consisting of system state variables and parameters. Trajectory sensitivity analysis (TSA) has been used in previous publications as a method for power system security and stability assessment, and the mathematical formulation of TSA lends itself well to some of the time domain power system simulation techniques. Existing special protection schemes often have limited sets of goals and …


Configuration Management In Manufacturing And Assembly: Case Study And Enabler Development, Keith Phelan Dec 2015

Configuration Management In Manufacturing And Assembly: Case Study And Enabler Development, Keith Phelan

All Dissertations

The overall goal of this research is to improve the product configuration change management process. The increase in the demand for highly customizable products has led to many manufacturers using mass customization to meet the constantly changing demands of a wide consumer base. However, effectively managing the configurations can be difficult, especially in large manufacturers or for complex products with a large number of possible configurations. This is largely due to a combination of the scope of the configuration management system and the difficulty in understanding how changes to one element of a configuration can propagate through the configuration system. …


Electrochemical Enhancement Of Butanol Production And Xylose Consumption In Pure And Mixed Culture Fermentations, Jovan Popovic Dec 2015

Electrochemical Enhancement Of Butanol Production And Xylose Consumption In Pure And Mixed Culture Fermentations, Jovan Popovic

All Dissertations

The volatility of foreign and domestic petroleum markets has prompted initiatives for the development of alternative liquid energy carriers which have the capacity to accommodate our current transportation infrastructure. Butanol, which has an energy density similar to that of gasoline and can be produced through the fermentation of carbohydrates by solventogenic Clostridia, has been investigated as a supplement or direct replacement to gasoline. However, most butanol fermentations rely on glucose as a feedstock which is in direct competition with our food supply, and this requires the exploration of alternative fermentable substrates. This study investigates the use of electrochemical fermentation modifications …


On Subgrid-Scale Physics In The Convective Atmospheric Surface Layer, Khuong Nguyen Dec 2015

On Subgrid-Scale Physics In The Convective Atmospheric Surface Layer, Khuong Nguyen

All Dissertations

The dynamics of the subgrid-scale (SGS) stress and scalar flux in the convective atmospheric surface layer are studied using field measurements from the Advection Horizontal Array Turbulence Study (AHATS). We extend the array technique previously used to evaluate the SGS velocity and temperature to include measurements of the fluctuating pressure, enabling separation of the resolvable- and subgrid-scale pressure and allowing for the first-ever observations of the pressure covariance terms and the full SGS budgets. Non-dimensional forms of the budget terms are analysed as functions of the surface-layer stability parameter and the ratio of the wavelength of the spectral peak of …


Effects Of Growth Factor Supplementation And Environmental Conditions On Human Adipose-Derived Stem Cell Differentiation Towards Urothelial Lineage, James Turner Dec 2015

Effects Of Growth Factor Supplementation And Environmental Conditions On Human Adipose-Derived Stem Cell Differentiation Towards Urothelial Lineage, James Turner

All Dissertations

In recent years, tissue engineering of the bladder has undergone many technological advances. Autologous urothelial cells have been used in animal models and have shown increased performance for ureteral reconstruction compared to unseeded grafts. However, since patients may lack a reliable source of native urothelial cells due to the nature of their specific bladder disease, autologous cells are not an ideal source clinically, and an alternate cell source must be explored. Adipose derived stem cells (ADSCs) are an attractive cell source for such regenerative medicine applications as they have been extensively studied for their multipotential differentiation, immunosuppressive properties, ease of …


The Professional Constructor, Full Issue, Volume 39, Number 02 Oct 2015

The Professional Constructor, Full Issue, Volume 39, Number 02

The Professional Constructor

No abstract provided.


Measuring The Potential Impact Of Combination Hiv Prevention In Sub-Saharan Africa, Amin Khademi, Sunanth Anand, David Potts Sep 2015

Measuring The Potential Impact Of Combination Hiv Prevention In Sub-Saharan Africa, Amin Khademi, Sunanth Anand, David Potts

Publications

A public health approach to combination HIV prevention is advocated to contain the epidemic in sub-Saharan Africa. We explore the implications of universal access to treatment along with HIV education scale-up in the region. We develop an HIV transmission model to investigate the impacts of universal access to treatment, as well as an analytical framework to estimate the effects of HIV education scale-up on the epidemic. We calibrate the model with data from South Africa and simulate the impacts of universal access to treatment along with HIV education scale-up on prevalence, incidence, and HIV-related deaths over a course of 15 …


Project Delivery Methods For The Construction Of Public Schools In The Southeastern United States, Dennis C. Bausman Sep 2015

Project Delivery Methods For The Construction Of Public Schools In The Southeastern United States, Dennis C. Bausman

The Professional Constructor

Construction of new facilities is a risky enterprise due to the situational aspects of the project, multiple parties involved in the process, timing and budget constraints, and the design features and quality levels required by the owner. Decision makers are charged with selecting a project delivery system to successfully manage the design and construction process in order to meet the owner’s needs. This paper documents the delivery methods utilized for the construction of public schools in Florida, Georgia, North Carolina, and South Carolina from 2006 to 2012 and provides insight into the reasons for the delivery method selections made by …


Construction Degree Graduates: An Evaluation Of Depth Of Skill Understanding And Skill Priority By Construction Industry Professionals, Ben F. Bigelow, Edelmiro Escamilla, Lauren Kuecker Sep 2015

Construction Degree Graduates: An Evaluation Of Depth Of Skill Understanding And Skill Priority By Construction Industry Professionals, Ben F. Bigelow, Edelmiro Escamilla, Lauren Kuecker

The Professional Constructor

Previous studies have been conducted to determine the skills the construction industry expects graduates and entry level professionals to possess. The majority of those studies report soft skills and technical expertise as the main qualities graduates should have upon entering the industry. Many differing skills have been reported, but neither the expected depth of understanding in those skills nor the industry’s priority of those skills have been explored. To do so, a survey was administered to members of the Construction Industry Advisory Council at Texas A&M University asking these questions. Depth of understanding was evaluated on a four level basis …


Accident Patterns In Road Construction Work Zones, Tariq Shehab, Leah Phu Sep 2015

Accident Patterns In Road Construction Work Zones, Tariq Shehab, Leah Phu

The Professional Constructor

Traffic safety in road construction zones has always been a major concern for engineering practitioners, departments of transportation, law enforcement professionals, researchers and many others. Due to the deteriorated condition of road and underground infrastructure facilities in the United States, the number of rehabilitation projects and their associated traffic accidents have increased over the past few years. To perform the needed road and underground utility rehabilitation activities in safer environments, researchers need to understand the causes behind these accidents. Although many researchers have been exploring the safety of many construction activities, research pertaining to road construction projects is lacking and …


Reviewer Thank You, Jason Lucas Sep 2015

Reviewer Thank You, Jason Lucas

The Professional Constructor

No abstract provided.


A Framework For Small-Scale Construction Projects By Ngos In Developing Countries, James D. Goedert, Bradley Cory Sep 2015

A Framework For Small-Scale Construction Projects By Ngos In Developing Countries, James D. Goedert, Bradley Cory

The Professional Constructor

This paper outlines a theoretical framework for NGOs who are building small-scale construction projects in developing countries. The framework is a step-by-step procedure to guide NGOs from developing project parameters at the start of the project with the partner to a locally controlled sustainable project closeout. The authors used the integrative project delivery approach along with past construction research models and personal experience to guide the development of the framework. Steps within the framework are illustrated using five projects from three countries. This work assumes that the ultimate objective of the project is local operational sustainability with the NGO’s presence …


Effect Of Respiration On Cardiac Filling At Rest And During Exercise In Fontan Patients: A Clinical And Computational Modeling Study, Alexander Van De Bruaene, Guido Claessen, Andre La Gerche, Ethan Kung, Alison Marsden, Pieter De Meester, Sarah Devroe, Jan Bogaert, Piet Claus, Hein Heidbuchel, Werner Budts, Marc Gewillig Aug 2015

Effect Of Respiration On Cardiac Filling At Rest And During Exercise In Fontan Patients: A Clinical And Computational Modeling Study, Alexander Van De Bruaene, Guido Claessen, Andre La Gerche, Ethan Kung, Alison Marsden, Pieter De Meester, Sarah Devroe, Jan Bogaert, Piet Claus, Hein Heidbuchel, Werner Budts, Marc Gewillig

Publications

Due to the absence of a sub-pulmonary ventricle, the Fontan circulation is sensitive to respiration-induced changes in intrathoracic pressure. However, the importance of a ‘respiratory pump’ in creating forward flow remains controversial. We aimed at evaluating the effect of respiration on ventricular filling during exercise using clinical data and computational modeling predictions. Ten Fontan patients (6 male, 20 ± 4 years) underwent ungated cardiac magnetic resonance (CMR) imaging at rest and during supine bicycle exercise to evaluate systemic ventricular volumes (end-diastolic volume index (EDVi), end-systolic volume index (ESVi) and stroke volume index (SVi)) during normal respiration and a Valsalva maneuver. …


A Compact Driving Simulator To Support Research And Training Needs - Hardware, Software, And Assessment, Qimin Yao Aug 2015

A Compact Driving Simulator To Support Research And Training Needs - Hardware, Software, And Assessment, Qimin Yao

All Theses

In 2009, there were 10.8 million automotive crashes in the United States. When reviewing these incidents, young drivers were the over-represented group who were involved in these vehicular crashes. One reason that these young drivers have such high crash rates is that they often do not possess extensive driving knowledge and typically lack driving experience. Over the past three decades, researchers have investigated the driver training process which includes the classroom and behind the wheel to help address teaching the deficiencies in the driver education program. To complement the current driver education process, automotive simulators can be utilized to teach …


The Effect Of High-Pressure Devitrification And Densification On Ballistic-Penetration Resistance Of Fused Silica, Vasudeva Avuthu Aug 2015

The Effect Of High-Pressure Devitrification And Densification On Ballistic-Penetration Resistance Of Fused Silica, Vasudeva Avuthu

All Theses

Despite the clear benefits offered by more advanced transparent materials, (e.g. transparent ceramics offer a very attractive combination of high stiffness and high hardness levels, highly-ductile transparent polymers provide superior fragment-containing capabilities, etc.), ballistic ceramic-glass like fused-silica remains an important constituent material in a majority of transparent impact-resistant structures (e.g. windshields and windows of military vehicles, portholes in ships, ground vehicles and spacecraft) used today. Among the main reasons for the wide-scale use of glass, the following three are most frequently cited: (i) glass-structure fabrication technologies enable the production of curved, large surface-area, transparent structures with thickness approaching several inches; …


The Partially Rechargeable Electric Vehicle Routing Problem With Time Windows And Capacitated Charging Stations, Navid Matin Moghaddam Aug 2015

The Partially Rechargeable Electric Vehicle Routing Problem With Time Windows And Capacitated Charging Stations, Navid Matin Moghaddam

All Theses

Electric vehicles are potentially beneficial for both the environment and an organization's bottom line. These benefits include, but are not limited to, reduced fuel costs, government tax incentives, reduced greenhouse gas emissions, and the ability to promote a company's "green" image. In order to decide whether or not to convert or purchase electric trucks and install charging facilities, decision makers need to consider many factors including onboard battery capacity, delivery or service assignments, scheduling and routes, as well as weather and traffic conditions in a well-defined modeling framework. We develop a model to solve the partially rechargeable electric vehicle routing …


The Effect Of Procedural Changes On The Rate Of Clinical Alarms In The Intensive Care Unit, Puneeth Kalavagunta Aug 2015

The Effect Of Procedural Changes On The Rate Of Clinical Alarms In The Intensive Care Unit, Puneeth Kalavagunta

All Theses

Clinical alarms have become an indispensable part of medical environment, but issues related to alarm artifacts, false alarms, and alarm fatigue have been identified. A national online survey administered to hospitals stated healthcare workers determined that 81% of respondents agreed that alarms occur frequently, 77% agreed that excessive clinical alarms disrupt patient care, and 78% agreed that reduced trust in alarms cause caregivers to disable them (Korniewicz, Clark, & David, 2008). Studies have suggested that preparation of skin of the patient improves electrode-skin contact, thereby resulting in fewer artifacts (Hermens, Freriks, Disselhorst-Klug, & Rau, 2000). Additionally, clinical studies have shown …


Feasibility Analysis Of Steam Ventilation In Supercavitation Design, Austin Culberson Aug 2015

Feasibility Analysis Of Steam Ventilation In Supercavitation Design, Austin Culberson

All Theses

The complete envelopment of a submerged object by a continuous cavity, or supercavity, results in significant reduction of the skin drag acting on the object, allowing for substantial increases in the maximum speeds of underwater devices. The formation of supercavities often requires supplemental ventilation, traditionally by non-condensable gasses, as natural supercavitation occurs at relative speeds between the object and liquid medium that are infeasible for the device to reach without supercavitation itself. The aim of this research is to investigate the feasibility of vaporous ventilation in supercavitation design with the hope of reducing non-condensable ventilation requirements which are inherently limited …


Finite Element Analysis Of Effective Mechanical Properties Of Hierarchical Honeycomb Structures, Ninad Gandhi Aug 2015

Finite Element Analysis Of Effective Mechanical Properties Of Hierarchical Honeycomb Structures, Ninad Gandhi

All Theses

Honeycomb structures are widely used in engineering applications mainly due to their high strength to weight ratio. By changing the base material and geometry of the repeating unit cell structure, target effective properties can be achieved. Hierarchical honeycomb structures are known to have enhanced mechanical properties when compared to regular honeycomb structures. Therefore, it is important to understand and quantify the mechanical properties and the variation of these properties with the presence of hierarchy. This investigation builds upon prior work and considers the mechanical properties of two dimensional hierarchical honeycomb structures. Previous research of hierarchical honeycomb structures studied replacing the …


Designing A Minimal-Knowledge Controller To Achieve Fast, Stable Growth For Recombinant Escherichia Coli Cultures, Matthew E. Pepper Aug 2015

Designing A Minimal-Knowledge Controller To Achieve Fast, Stable Growth For Recombinant Escherichia Coli Cultures, Matthew E. Pepper

All Dissertations

The biopharmaceutical industry is constantly developing new recombinant Es-cherichia coli strains to bring new products to market. In early stages of development, small scale bioreactors are used to make the product and explore di˙erent growth pro-tocols. Researchers spend significant time finding a feed rate profile that will give fast growth and low byproduct accumulation. The objective for the controller pre-sented in this work is to achieve fast growth and low acetate accumulation for an E.coli fermentation. The controller does not rely on previous characterization data or models but on fundamental metabolic relationships between oxygen and glucose as dictated by the …


Acoustic Performance Of Reiterated Hierarchical Honeycomb Structures, Naveen Nainar Aug 2015

Acoustic Performance Of Reiterated Hierarchical Honeycomb Structures, Naveen Nainar

All Theses

Sandwich panels constructed from honeycomb structures have been found to reduce sound transmission and improve vibration isolation. In this work, reiterated hierarchical honeycomb structures have been modeled for the core in sandwich panels and studied for sound transmission properties using finite element analysis. Several honeycomb unit cell geometries are considered, including, regular hexagonal, auxetic with properties of negative Poisson’s ratio, and different reiterated hierarchical structures. Previous studies have shown that auxetic honeycomb structures exhibit improved sound transmission loss compared to regular honeycomb sandwich panels. Two different orientations of the honeycomb unit cell geometry have been studied, namely, the zigzag and …


Acoustic Scattering Response Of Hierarchic Honeycomb Structures For Cylindrical And Spherical Structures, Arun Mor Aug 2015

Acoustic Scattering Response Of Hierarchic Honeycomb Structures For Cylindrical And Spherical Structures, Arun Mor

All Theses

Sandwich panels with honeycomb core are often employed in structures for improved mechanical properties with lightweight. Honeycombs are defined by non-overlapping and periodic unit cells. Most research conducted on these sandwich panels focuses on stiffness and strength properties. The acoustic aspect of these panels has been focused on sound transmission loss. For acoustics, previous studies used effective honeycomb orthotropic elastic moduli based on Cartesian unit cell geometry to model the core as a homogeneous structure. While efficient, this modeling approach loses accuracy at higher frequencies. Furthermore, when used for curved panels, the effective moduli are only approximate. In this work, …


Exploring The Use Of Bamboo Reinforced Rubberized Concrete (Brrc) As A Sustainable Standard System, Muxing Ding Aug 2015

Exploring The Use Of Bamboo Reinforced Rubberized Concrete (Brrc) As A Sustainable Standard System, Muxing Ding

All Theses

Concrete is the predominant material used in construction, in particular, for commercial structures. It has many advantages including low cost, high availability, low maintenance, high compressive strength and high durability. However concrete is a brittle material with very low tensile strength. Hence, steel, in the form of rebar is typically used to reinforce concrete. The cost of steel rebar is relatively high, especially in many developing countries compared to their average income. Therefore, minimal rebar is used to reinforce concrete homes and other low-rise buildings in developing countries such as Haiti leading to unsafe structures, especially during earthquakes. The high …


Inertial Particle Dynamics In Simple Vortex Flow Configurations, Senbagaraman Sudarsanam Aug 2015

Inertial Particle Dynamics In Simple Vortex Flow Configurations, Senbagaraman Sudarsanam

All Theses

Dynamics of inertial particles differ significantly from that of the underlying fluid flow. This difference in the dynamics of Inertial particles from that of fluid tracers can be exploited to segregate particles by size. While external forces can be used to manipulate the dynamics of such particles, using hydrodynamic forces which are always present in the flows of interest to manipulate inertial particle dynamics offers several advantages. Vorticity is one such phenomenon that is frequently encountered in natural and industrial flows. Thus, the dynamics of inertial particles have been studied in the presence of simple vortex flow configurations in this …


Functional Thinking: A Protocol Study, Ashwinraj Thiagarajan Aug 2015

Functional Thinking: A Protocol Study, Ashwinraj Thiagarajan

All Theses

This thesis reports a protocol study that examines how designers construct function structure graphs as they understand and develop solutions for novel design problems. Eight voluntary design engineers, with two to four years of experience in product design and function modeling are presented with a novel design problem for which they have to develop functional models as part of concept development. The modeling actions are video recorded and the data is analyzed using a predefined protocol that encodes the addition, deletion, and modification of model elements such as functions, flows, and text, and also other activities such as reading the …