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 1831 - 1860 of 2584

Full-Text Articles in Engineering

Electrical Coupling Between Micropatterned Cardiomyocytes And Stem Cells, Zhen Ma Dec 2011

Electrical Coupling Between Micropatterned Cardiomyocytes And Stem Cells, Zhen Ma

All Dissertations

To understand how stem cells functionally couple with native cardiomyocytes is crucial for cell-based therapies to restore the loss of cardiomyocytes that occurs during heart infarction and other cardiac diseases. Due to the complexity of the in vivo environment, our knowledge of cell coupling is heavily dependent on cell-culture models. However, conventional in vitro studies involve undefined cell shapes and random length of cell-cell contacts in addition to the presence of multiple homotypic and heterotypic contacts between interacting cells. Thus, it has not been feasible to study electrical coupling corresponding to isolated specific types of cell contact modes.
To address …

Go to article

Characterizing Mechanical Heterogeneity In Cardiovascular Cells, Sandra Deitch Dec 2011

Characterizing Mechanical Heterogeneity In Cardiovascular Cells, Sandra Deitch

All Dissertations

Most tissue-level mechanical models assume homogeneous mechanical properties within a single cell type. However, measurements of cellular mechanical properties show large variability in whole-cell mechanical properties between cells from a single population. This heterogeneity has been observed in many cell populations and with several measurement techniques but the sources are not yet fully understood. Cell mechanical properties are directly related to the composition and organization of the cytoskeleton, which is physically coupled to neighboring cells through adherens junctions and to underlying matrix scaffolds through focal adhesion complexes. As such, we believe that this high level of heterogeneity can be attributed …

Go to article

Pitch-Based Activated Carbon Fibers: The Effect Of Precursor Composition On Pore Structure, Halil Tekinalp Dec 2011

Pitch-Based Activated Carbon Fibers: The Effect Of Precursor Composition On Pore Structure, Halil Tekinalp

All Dissertations

Although researchers have previously investigated the effect of precursor differences on the final properties of activated carbon fibers (ACFs), those precursors were not well-characterized. In particular, detailed information about their molecular composition and anisotropy was not available.
In this study, seven oligomeric fractions, each of well-defined composition and molecular weight (mol wt) distribution, were isolated from a commercially produced isotropic petroleum pitch (i.e., Marathon M–50) and used for the production of ACFs. Four of these precursors of varying oligomeric composition were fully isotropic and three contained different levels of mesophase, so that the effects of molecular composition and molecular order …

Go to article

Evaluating The Use Of Functional Representations For Ideation In Conceptual Design, Benjamin Caldwell Dec 2011

Evaluating The Use Of Functional Representations For Ideation In Conceptual Design, Benjamin Caldwell

All Dissertations

Functional representations are often used in the conceptual stages of design because they encourage the designer to focus on the intended use and purpose of a system rather than the physical solution. Function models have been proposed by many researchers as a tool to expand the solution search space and guide concept generation, and many design tools have been created to support function-based design. These tools require designers to create function models of new or existing artifacts, but there is limited published research describing what types of functions should be included in a model or the appropriate level of abstraction …

Go to article

Accelerating Pattern Recognition Algorithms On Parallel Computing Architectures, Kenneth Rice Dec 2011

Accelerating Pattern Recognition Algorithms On Parallel Computing Architectures, Kenneth Rice

All Dissertations

The move to more parallel computing architectures places more responsibility on the programmer to achieve greater performance. The programmer must now have a greater understanding of the underlying architecture and the inherent algorithmic parallelism. Using parallel computing architectures for exploiting algorithmic parallelism can be a complex task. This dissertation demonstrates various techniques for using parallel computing architectures to exploit algorithmic parallelism. Specifically, three pattern recognition (PR) approaches are examined for acceleration across multiple parallel computing architectures, namely field programmable gate arrays (FPGAs) and general purpose graphical processing units (GPGPUs).
Phase-only filter correlation for fingerprint identification was studied as the first …

Go to article

A Method For Evaluating Manufacturing Change In Engineering Design, Christopher Brooks Aug 2011

A Method For Evaluating Manufacturing Change In Engineering Design, Christopher Brooks

All Theses

Design changes are a frequent occurrence over the life of a product that may be initiated by an update to the product functionality, new customer needs, or generational improvements. The costs associated with these changes are undesirable, and are often times greatly inflated by additional, unanticipated changes that result from change propagating throughout the system. Propagation paths occur when an initiating change to a component necessitates subsequent changes to coupled components, as the change continues to propagate throughout the product architecture. The nature of this change propagation is challenging to characterize and accurately predict. To address this issue, a change …

Go to article

Stress Relaxation Of Glass Using A Parallel Plate Viscometer, Guy-Marie Vallet Aug 2011

Stress Relaxation Of Glass Using A Parallel Plate Viscometer, Guy-Marie Vallet

All Theses

Currently, grinding and polishing is the traditional method for manufacturing optical glass lenses. However, for a few years now, precision glass molding has gained importance for its flexibility in manufacturing aspheric lenses. With this new method, glass viscoelasticity and more specifically stress relaxation are important phenomena in the glass transition region to control the molding process and to predict the final lens shape.
The goal of this research is to extract stress relaxation parameters in shear of Pyrex¨ glass by using a Parallel Plate Viscometer (PPV). The PPV machine was originally created to measure the viscosity of glass solid cylinders …

Go to article

A History-Dependent Nonwetting Phase Trapping Model For Multiphase Flow Characteristic Curves, Christopher Patterson Aug 2011

A History-Dependent Nonwetting Phase Trapping Model For Multiphase Flow Characteristic Curves, Christopher Patterson

All Theses

Characteristic curves used in numerical multiphase flow simulators describe relative permeability-saturation and capillary pressure-saturation relationships for flow simulations. Characteristic curves are typically non-hysteretic; meaning they are monotonic functions of saturation and are limited to a single value for residual saturation. Implications of residual saturation are important for environmental, petroleum, and geologic carbon sequestration modeling. However, hysteretic characteristic curves predict that trapped residual saturation depends on the local saturation history. The use of hysteretic characteristic curves is critical to predicting the residual saturation and ultimately the mobility of a nonwetting phase such as supercritical CO2 or a nonaqueous phase liquid (NAPL). …

Go to article

Model-Based System Fault Diagnosis Utilizing Adaptive Threshold With Application To Automotive Electrical Systems, Ali Hashemi Aug 2011

Model-Based System Fault Diagnosis Utilizing Adaptive Threshold With Application To Automotive Electrical Systems, Ali Hashemi

All Theses

Recent advancement in the field of automotive industry is largely due to the addition of electrical and electronic equipment; some of the safety features in the vehicle and advanced driver assistance systems are examples of such equipment. Furthermore, safe operation of the vehicle is highly dependent on the electrical power generation and storage system (EPGS). Therefore, to ensure optimal operation of this system, a reliable diagnosis of the system is essential. However, as the complexity of the electrical systems has increased, the identification of a malfunction has become an increasingly difficult task to handle.
In the current work, a model-based …

Go to article

Influence Of Natural Organic Matter On Plutonium Sorption To Gibbsite, Laura Simpkins Aug 2011

Influence Of Natural Organic Matter On Plutonium Sorption To Gibbsite, Laura Simpkins

All Theses

Understanding plutonium geochemical behavior is imperative to the development of schemes for remediation of plutonium environmental contamination and accurate assessment of risks posed by the disposal of plutonium bearing wastes. The primary mechanism of plutonium mobility in the environment is subsurface transport. The mobility of plutonium is significantly influenced by redox and complexation reactions. Although the effects of surface mediated redox reactions on plutonium's subsurface mobility have been previously documented, little has been done to determine the impact of organic materials on sorption behavior and oxidation states. To adequately predict the behavior of plutonium in the environment, the influence of …

Go to article

Substrate Topography Design And Fabrication For Osteoblast And Dental Pulp Stem Cells Studies, Gloria Chen Aug 2011

Substrate Topography Design And Fabrication For Osteoblast And Dental Pulp Stem Cells Studies, Gloria Chen

All Theses

Research for cell guidance based tissue engineering has rapidly grown due to the increasing interest in tissue engineering and reconstructive medicine applications, such as cranial reconstruction. Many research teams have begun the process of identifying what factors influence cell behavior (including cell growth, proliferation, alignment and spreading). Published studies have pointed to the influence of the cell medial pH, substrate stiffness, chemistry and topography. Conclusive results are often hard to identify since researchers often vary many of these factors simultaneously and it is hard to decouple individual factor influence. These reports also points out that the cellular response can be …

Go to article

Oxygenate Synthesis During Co Hydrogenation On Cocuzno- Based Catalysts, Yu-Tung Tsai Aug 2011

Oxygenate Synthesis During Co Hydrogenation On Cocuzno- Based Catalysts, Yu-Tung Tsai

All Dissertations

The research of catalytic synthesis of methanol and other higher alcohols from CO hydrogenation has received great attention since 1980s. The focus of this research is to establish a better fundamental insight into heterogeneous metal catalysts for oxygenate (especially alcohol) synthesis by CO hydrogenation.
Co-based catalysts have been reported widely as the high-performance Fischer-Tropsch Synthesis (FTS) catalysts. The solid base, hydrotalcite (HT), using as a support for Co catalysts resulted in higher activity for CO hydrogenation comparing to other supports (pre-calcined hydrotalcite, MgO and Al2O3). The activities of Co/HT reduced at different reduction temperatures (300-600oC) were …

Go to article

Modeling, Finite Element Analysis, And Optimization Of Non-Pneumatic Tire (Npt) For The Minimization Of Rolling Resistance, Mallikarjun Veeramurthy Aug 2011

Modeling, Finite Element Analysis, And Optimization Of Non-Pneumatic Tire (Npt) For The Minimization Of Rolling Resistance, Mallikarjun Veeramurthy

All Theses

Recently, the development of non-pneumatic tires (NPT) such as the Michelin Tweel is receiving increased attention due to potential advantages over pneumatic tires such as low mass, no run flat, good contact pressure distribution, and low rolling resistance (RR). This study focuses on the design of a NPT based on properties of vertical stiffness, contact pressure, and rolling energy loss. Using a finite element (FE) model, a parametric study is conducted to study the effect on vertical stiffness, contact pressure, and rolling resistance (RR) response considering three design variables: (1) thickness of the spokes, (2) the shear band thickness, and …

Go to article

An Investigation Into Segmenting Traffic Images Using Various Types Of Graph Cuts, Jonathan Dinger Aug 2011

An Investigation Into Segmenting Traffic Images Using Various Types Of Graph Cuts, Jonathan Dinger

All Theses

In computer vision, graph cuts are a way of segmenting an image into multiple areas. Graphs are built using one node for each pixel in the image combined with two extra nodes, known as the source and the sink. Each node is connected to several other nodes using edges, and each edge has a specific weight. Using different weighting schemes, different segmentations can be performed based on the properties used to create the weights. The cuts themselves are performed using an implementation of a solution to the maximum flow problem, which is then changed into a minimum cut according to …

Go to article

Dynamics And Control Of The Shoot-The-Moon Tabletop Game, Peng Xu Aug 2011

Dynamics And Control Of The Shoot-The-Moon Tabletop Game, Peng Xu

All Theses

The classic table-top game Shoot-the-Moon has interesting dynamics despite its simple structure, consisting of a steel ball rolling on two cylindrical rods. The two sloped rods are hinged at the lower ends and allowed to freely slide in a slot at the higher end. The ball can amazingly roll upward along the rods under carefully manipulation of the rods. There is also an interaction between ball rotation and translation that cause the ball to ``shoot'' (quickly accelerate).
In this thesis, the kinematics are developed for Shoot-the-Moon and then equations of motion are derived using both Lagrangian and Newtonian approaches. The …

Go to article

Determination Of Freshwater Algal Biomass And Sulfolipid Content As Functions Of Inorganic Carbon Treatment, Melissa Morella Aug 2011

Determination Of Freshwater Algal Biomass And Sulfolipid Content As Functions Of Inorganic Carbon Treatment, Melissa Morella

All Theses

Cultures of mixed freshwater algae were grown in open batch reactors made up of modified BG-11 media that contained 0, 25, 50 or 100% of the suggested inorganic carbon content (0, 0.5, 0.1 and 0.2 g/L Na2CO3) to assess the subsequent production of the high-value product, sulfoquinovosyl diacylglycerol (SQDG). After 25 days of growth, the reactors were composed of primarily Oscillatoria growth. All four reactors exhibited a trend of increasing biomass and alkalinity with time, and an initial increase then decrease in pH. The total inorganic carbon (TIC) in all reactors exhibited a mirrored, opposite trend …

Go to article

Mixture Fraction Imaging Based On Photodissociation Spectroscopy And Two Photon Laser Induced Fluorescence, Yan Zhao Aug 2011

Mixture Fraction Imaging Based On Photodissociation Spectroscopy And Two Photon Laser Induced Fluorescence, Yan Zhao

All Dissertations

The study of turbulent combustion calls for new diagnostics that can measure multidimensional mixture fraction under a wide range of flame conditions. A laser diagnostic technique based on photodissociation spectroscopy (PDS) is proposed to address this need. This thesis describes the concept of the PDS-based diagnostic, reports its experimental demonstration in a non-premixed jet flame, and assesses its performance and applicable range. The two-photon laser induced fluorescence (TPLIF) technique used in conjugate with the PDS is analyzed numerically in line and planar imaging configuration.
The new mixture fraction imaging technique is centered around the creative use of photodissociation (PD) for …

Go to article

Investigation Of Two-Phase Behavior In Capillary Evaporators With Liquid Core Visualization, Brian D'Entremont Aug 2011

Investigation Of Two-Phase Behavior In Capillary Evaporators With Liquid Core Visualization, Brian D'Entremont

All Dissertations

The Capillary Pumped Loop (CPL) and Loop Heat Pipe (LHP) are thermal management devices which are high performance derivatives of the conventional heat pipe. Both consist of a discrete evaporator containing a porous solid wick which is coupled via smoothed walled tubing to a condenser. In a CPL, fluid inventory is managed by a reservoir attached to the liquid line which is controlled in temperature. In an LHP, fluid inventory is managed passively by a compensation chamber which is integral to the evaporator.
In this study, a borescope was inserted into the liquid core and compensation chamber of LHP evaporators …

Go to article

Computational Analysis Of The Dynamic Forces In Drive Train Components Of An Offshore Wind Turbines, Artem Korobenko Aug 2011

Computational Analysis Of The Dynamic Forces In Drive Train Components Of An Offshore Wind Turbines, Artem Korobenko

All Theses

Wind has good potential for contributing to the national energy supply. Offshore sites and deep sea locations can be especially attractive as the wind turbine market grows. In such places larger wind resources are available with reduced turbulence intensity and wind shear. In addition, visual impact along with noise aspects are reduced. Offshore siting requires greater attention to structural stability and endurance. Forces on drive train components, such as the bearing system, are not well understood.
This work presents the development a model that calculates dynamical forces in drive train components of off-shore wind turbines. The model of a 5MW …

Go to article

Understanding The Role Of Functions And Interactions In The Product Design, Raveesh Ramachandran Aug 2011

Understanding The Role Of Functions And Interactions In The Product Design, Raveesh Ramachandran

All Theses

Engineering designers often generate design concepts based on a functional understanding of the problem. Many engineering textbooks encourage designers to abstract the essential problem to a higher-level functional representation of the product and subsequently develop solutions to the functional needs. However, a functional perspective of design does not provide a complete view of what the product must do and how the product must interact with users and other parts. To address this, an alternative modeling approach has been developed to complement the traditional functional modeling approaches. Two such approaches include (1) activity modeling to capture the user actions from production …

Go to article

Cfd Analysis Of The Under Hood Of A Car For Packaging Considerations, Sreekanth Reddy Gondipalle Aug 2011

Cfd Analysis Of The Under Hood Of A Car For Packaging Considerations, Sreekanth Reddy Gondipalle

All Theses

In recent years, there has been an increase in demand towards the improvement of car design for achieving better performance and increasing passenger comfort. Improving the design of individual components to meet the customer needs for improved vehicle performance alone is not enough. Interactions of these components with the surrounding components and their placement should also be investigated. Placement of these components in the under hood space forms a 3-Dimensional packaging problem. In the past, a multi objective optimization process was setup to determine the optimal placement of these components in the car under hood space. Three main objectives were …

Go to article

Effect Of Different Oxygen Barrier Pouches On The Quality Of Retorted Carrots, Sarah Khor Aug 2011

Effect Of Different Oxygen Barrier Pouches On The Quality Of Retorted Carrots, Sarah Khor

All Theses

Thermally processed (TP) baby carrots were packaged in pouches with varying oxygen transmission rate (OTR) pouches. The pouches were four layer laminate (PET-Nylon-Barrier-CPP) with barrier layer being foil, aluminum oxide (AlOx), ethylene vinyl alcohol (EVOH), and nylon. Retort pouches were placed in boxes that were stored in an environmental chamber (43 °C, 50%RH). The objective of the study was to determine an alternative barrier retort pouch that is microwavable and still had similar barrier functions to foil for baby carrots and determine how the alternative compare with regard to shelf life. Instrumental analysis of color (L*, a*, b*) and texture …

Go to article

A Priori Analysis Of Subgrid-Scale Pressure In High Pressure H2/O2 Mixing And Reacting Shear Layers, Zhiyuan Ma Aug 2011

A Priori Analysis Of Subgrid-Scale Pressure In High Pressure H2/O2 Mixing And Reacting Shear Layers, Zhiyuan Ma

All Theses

An a priori analysis of subgrid-scale pressure in high pressure combustion is carried out using three different flow fields obtained by direct numerical simulation (DNS). The simulations directly solve the Navier-Stokes equations of high pressure, transitional H2/O2 mixing and reacting shear layers employing a cubic Peng-Robinson real gas state equation. Detailed chemistry, multicomponent, differential, and cross diffusion are included. The results are analyzed to provide subgrid information relevant to Large Eddy Simulation (LES) of turbulent combustion. The analysis includes a detailed comparison of the actual filtered pressure with its corresponding form evaluated with the filtered primitive variables. …

Go to article

Structural Health Monitoring Of Historic Masonry Monuments, Saurabh Prabhu Aug 2011

Structural Health Monitoring Of Historic Masonry Monuments, Saurabh Prabhu

All Theses

Structural Health Monitoring (SHM) is a well-accepted diagnostic technique being used to evaluate modern structures. This method involves monitoring the vibration response of a structure to detect changes in its structural state. The primary intention of this thesis is to address two practical and technical difficulties encountered in deploying SHM on historic masonry monuments: (i) the selection of suitable low dimensional vibration response features that are highly sensitive to the presence and extent of damage, while having low sensitivity to extraneous noise and (ii) the selection of optimal sensor locations for efficient system identification applied to Gothic Cathedrals. Both of …

Go to article

Modeling And Finite Element Alaysis Of Fluid Structure Interaction In A Wind Energy Harvester, Bargav Cheruku Aug 2011

Modeling And Finite Element Alaysis Of Fluid Structure Interaction In A Wind Energy Harvester, Bargav Cheruku

All Theses

An energy harvesting system inspired by musicplaying harmonicas was developed for microwind power generation. The energy harvester uses flow-induced self-sustained oscillations of a piezoelectric beam embedded within a chamber to generate electric power. While the power generation capability of the energy harvester has been demonstrated previously, there is a lack of understanding behind the basic physics of the driving mechanism responsible for the self-sustained oscillations. In addition, the performance of the nonlinear multi-physics system with strong fluid and structure coupling depends on many physical and design parameters. A systematic study on the effects of these parameters is necessary for the …

Go to article

Constrained Layer Damping Of Honeycomb Composite Structures, Rohit Telukunta Aug 2011

Constrained Layer Damping Of Honeycomb Composite Structures, Rohit Telukunta

All Theses

Composite sandwich structures have replaced homogenous dense solids in many applications due to their advantages of high stiffness to weight ratio, and higher damping characteristics. Higher damping in engineering applications is desirable to reduce structural vibrations. The application of a viscoelastic layer between two thin face sheets gives rise to the concept of constrained layer damping which is an effective technique to achieve increased damping in engineering applications.
Honeycomb cellular structures are often used for the core in sandwich construction because of their low density and high stiffness properties. Regular honeycombs are defined by conventional hexagonal geometry, which gives rise …

Go to article

Molecular Dynamics Study Of Particle Impact Induced Bond Breaking Of Single-Walled Carbon Nanotubes And Quality Factors Of Nanocomposite Structures, Puroorava Annapaneni Aug 2011

Molecular Dynamics Study Of Particle Impact Induced Bond Breaking Of Single-Walled Carbon Nanotubes And Quality Factors Of Nanocomposite Structures, Puroorava Annapaneni

All Theses

Part A
Injection of particles to the side wall of single-walled carbon nanotubes (SWCNT) has been employed for doping and storage of particles on SWCNTs. In addition, particle bombardment can be used to cut and modify graphene structures. While the collision of hydrogen atoms with SWCNTs has been extensively studied, collision dynamic behavior of heavy particles with SWCNTs has not been well understood. To facilitate a better understanding of the particle-SWCNT collision process, in this work, we study the impact of five noble gas atoms (He, Ne, Ar, Kr, Xe) with SWCNTs and investigate particle impact induced CNT bond breaking …

Go to article

The Effect Of Barrier Properties Of Non-Foil Retort Films On Shelf Life Of Oxygen Sensitive Foods, Mahalaxmi Dharman Aug 2011

The Effect Of Barrier Properties Of Non-Foil Retort Films On Shelf Life Of Oxygen Sensitive Foods, Mahalaxmi Dharman

All Theses

A simulated food product sensitive to oxygen, which was a mixture of tomato paste, water, and corn oil (2:2:1), was filled into five different barrier coated pouches, a foil barrier and a low barrier pouch. These pouches were thermally processed at 250¡F for 30 minutes and stored in darkness under accelerated conditions (45±2¡C and 50±2%RH) for up to 180 days.
The simulant was analyzed for lipid oxidation by TBARS and lycopene degradation by colorimetry (L*,a*,b* values and Hue angle). The oxygen permeability (OP) in all the pouches increased by 5 to 500 fold after retort. TBARS values in all pouches …

Go to article

A Priori Analysis Of Subgrid-Scale Heat Flux Vectors In High Pressure H2/O2 Mixing And Reacting Shear Layers, Ayse Korucu Aug 2011

A Priori Analysis Of Subgrid-Scale Heat Flux Vectors In High Pressure H2/O2 Mixing And Reacting Shear Layers, Ayse Korucu

All Theses

A Direct Numerical Simulation (DNS) database of supercritical, transitional H2/O2 mixing and reacting shear layers is analyzed in an a priori manner to obtain subgrid statistics relevant to Large Eddy Simulation (LES) engineering modeling. The DNS employs a real gas state equation, detailed chemistry, accurate property models, multicomponent, differential, and cross diffusion. The parallel simulations were conducted using eighth order central finite differencing in conjunction with a fourth order accurate Runge-Kutta time integration, on resolutions up to 135 million grid points, and used up to 2,016 processing cores. All simulations are for an ambient pressure of 100 atm and are …

Go to article

Sensitivity Analysis Of Load Distribution In Light-Framed Wood Roof System Due To Typical Modeling Parameters, Ranjith Shivarudrappa Aug 2011

Sensitivity Analysis Of Load Distribution In Light-Framed Wood Roof System Due To Typical Modeling Parameters, Ranjith Shivarudrappa

All Theses

Since failure of roof systems in past high wind events have demonstrated the consequences of not maintaining a continuous load path from the roof to the foundation, many studies have been conducted to better understand this load path, including how loads are distributed in the system. The present study looks to add to the current knowledge of the vertical load path by focusing on uplift loads and by considering the sensitivity of different modeling parameters. This is done by developing and assessing load influence coefficients for various roof-to-wall (RTW) connections. An analytical model of a light-framed wood structure using finite …

Go to article

First Prev Next Last