Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Civil and Environmental Engineering (312)
- Mechanical Engineering (195)
- Electrical and Computer Engineering (179)
- Civil Engineering (164)
- Engineering Science and Materials (140)
-
- Biomedical Engineering and Bioengineering (120)
- Environmental Engineering (117)
- Engineering Mechanics (114)
- Materials Science and Engineering (106)
- Computer Engineering (78)
- Operations Research, Systems Engineering and Industrial Engineering (63)
- Physical Sciences and Mathematics (52)
- Industrial Engineering (39)
- Chemical Engineering (28)
- Computer-Aided Engineering and Design (24)
- Environmental Sciences (23)
- Life Sciences (22)
- Other Mechanical Engineering (19)
- Structural Engineering (19)
- Manufacturing (17)
- Medicine and Health Sciences (17)
- Computer Sciences (16)
- Power and Energy (16)
- Robotics (16)
- Social and Behavioral Sciences (16)
- Applied Mechanics (15)
- Automotive Engineering (15)
- Bioresource and Agricultural Engineering (15)
- Acoustics, Dynamics, and Controls (14)
- Keyword
-
- Optimization (16)
- Design (15)
- Bioremediation (13)
- Packaging (12)
- Machine Learning (11)
-
- Sustainability (10)
- Simulation (9)
- Modeling (7)
- Robotics (7)
- Biodegradation (6)
- Computer Vision (6)
- Concrete (6)
- Fiber (6)
- Finite Element Analysis (6)
- Glass (6)
- Manufacturing (6)
- Adsorption (5)
- Artificial Intelligence (5)
- Automation (5)
- Deep Learning (5)
- Drone (5)
- Dynamics (5)
- Honeycomb (5)
- Masonry (5)
- Nanoparticles (5)
- Radiation (5)
- Remediation (5)
- Scheduling (5)
- TCE (5)
- Tissue engineering (5)
Articles 1171 - 1200 of 1247
Full-Text Articles in Engineering
A Hydraulic Actuated Thermal Management System For Large Displacement Engine Cooling Systems, Peyton Frick
A Hydraulic Actuated Thermal Management System For Large Displacement Engine Cooling Systems, Peyton Frick
All Theses
The performance of automotive cooling systems can be improved by replacing the traditional mechanically driven radiator fan and water pump assemblies with computer controlled components. The introduction of electric servo-motors to drive the cooling components can improve temperature tracking, which should increase fuel efficiency and decrease tailpipe emissions. However, the power requirement for these electric motors increases with greater cooling demands if the radiator surface area remains constrained. For heavy-duty applications, where engines are subjected to significant cooling loads, electric motors may become impractical due to their increased size and power requirements; in these situations, hydraulic-based components are advantageous due …
Glycosaminoglycan Stabilization Reduces Tissue Buckling In Bioprosthetic Heart Valves, Sagar Shah
Glycosaminoglycan Stabilization Reduces Tissue Buckling In Bioprosthetic Heart Valves, Sagar Shah
All Theses
Currently, bioprosthetic heart valves are crosslinked with glutaraldehyde to prevent tissue degradation and to reduce tissue antigenicity. Glutaraldehyde forms stable crosslinks with collagen via a Schiff base reaction of the aldehyde with an amine group of the hydroxylysine/lysine in collagen. However, within a decade of implantation, 20-30% of these bioprostheses will become dysfunctional and over 50% will fail due to degeneration within 12-15 years post-operatively.
Gylcosaminoglycans, a major constituent of valvular tissue, play an important role in maintaining a hydrated environment necessary for absorbing compressive loads, modulating shear stresses, and resisting tissue buckling. One of the disadvantages of glutaraldehyde crosslinking …
Laser-Assisted Synthesis And Optical Properties Of Bismuth Nanorods, Jason Reppert
Laser-Assisted Synthesis And Optical Properties Of Bismuth Nanorods, Jason Reppert
All Theses
Bismuth in the bulk form is a semimetal with a rhombohedral structure. It has a small band overlap between the conduction and valence bands and a highly anisotropic electron effective-mass tensor. Thermoelectric materials, in which one of the three dimensions is in the nanometer regime, exhibit unique quantum confinement properties and have generated much interest in recent years. Theoretical investigations have suggested that nanowires with diameters <10 nm will possess a figure-of-merit ZT>2. Prior to this research, it has been shown by the Dresselhaus group at MIT that Bi nanowires with small enough diameters (~50 nm), prepared via the template-method, undergo a transition from a semimetal …
Nonlinear Modeling Of The Adsorption-Induced Surface Stress In Piezoelectrically-Driven Microcantilever Biosensors, Mana Afshari
Nonlinear Modeling Of The Adsorption-Induced Surface Stress In Piezoelectrically-Driven Microcantilever Biosensors, Mana Afshari
All Theses
Microcantilever-based biosensors are rapidly becoming an enabling sensing technology for a variety of label-free biological applications due to their extreme applicability, versatility and low cost. These sensors operate through the adsorption of species on the functionalized surface of microcantilevers. The adsorption of biological species induces surface stress which originates from the molecular interactions such as adhesion forces of attraction/repulsion, electrostatic forces or the surface charge redistribution of the underlying substrate. This surface stress, consequently, alters the resonance frequency of the microcantilever beam.
This study presents a general framework towards modeling resonance frequency changes induced due to the surface stress arising …
A Study Of Estimation Techniques And Of Mechatronic System Design And Testing, Brett Castelloe
A Study Of Estimation Techniques And Of Mechatronic System Design And Testing, Brett Castelloe
All Theses
This thesis is a collection of two projects that the author worked on during his master's studies at Clemson University. The first project--adaptive camera calibration--involves the design and simulation of an estimator for the calibration parameters of a camera. The second project--basket drive wear testing--includes the design of a test plan for measuring wear on a mechatronic system.
Transmission Gate Based Dual Rail Logic For Differential Power Analysis Resistant Circuits, Srinidhi Narasimha Char
Transmission Gate Based Dual Rail Logic For Differential Power Analysis Resistant Circuits, Srinidhi Narasimha Char
All Theses
Cryptographic devices with hardware implementation of the algorithms are increasingly being used in various applications. As a consequence, there is an increased need for security against the attacks on the cryptographic system. Among various attack techniques, side channel attacks pose a significant threat to the hardware implementation. Power analysis attacks are a type of side channel attack where the power leakage from the underlying hardware is used to eavesdrop on the hardware operation. Wave pipelined differential and dynamic logic (WDDL) has been found to be an effective countermeasure to power analysis. This thesis studies the use of transmission gate based …
Development And Evaluation Of An Enrichment Culture For Bioaugmentation Of The P-Area Chlorinated Ethene Plume At The Savannah River Site, Elizabeth Wood
Development And Evaluation Of An Enrichment Culture For Bioaugmentation Of The P-Area Chlorinated Ethene Plume At The Savannah River Site, Elizabeth Wood
All Theses
The Twin Lakes chlorinated ethene plume at the Department of Energy's
Savannah River Site (SRS) emerges in a wetland in which trichloroethene (TCE) is
completely reduced to ethene and ethane. Novel strains of Dehalococcoides have been
detected from the wetland area. The objectives of this study were 1) to develop an
enrichment culture capable of completely dechlorinating TCE and tetrachloroethene
(PCE) to ethene using samples from the wetland; 2) to evaluate the use of lactate,
emulsified vegetable oil and corn syrup as possible electron donors for biostimulation of
the P-area chlorinated ethene plume at SRS that is not undergoing natural …
Pursuit-Evasion With Acceleration, Sensing Limitation, And Electronic Counter Measures, Jing-En Pang
Pursuit-Evasion With Acceleration, Sensing Limitation, And Electronic Counter Measures, Jing-En Pang
All Theses
Abstract: The use of game theory to analyze the optimal behaviors of both pursuers and evaders originated with Isaac's work at the Rand Corporation in the 1950's. Although many variations of this problem have been considered, published work to date is limited to the case where both players have constant velocities. In this thesis, we extend previous work by allowing players to accelerate. Analysis of this new problem using Newton's laws imposes an additional constraint to the system, which is the relationship between players' velocities and allowed turning radius. We find that analysis of this relationship provides new insight into …
Analyzing Relationships Between Lightning And Rain In Order To Improve Estimation Accuracy Of Rain , Justin Lapp
Analyzing Relationships Between Lightning And Rain In Order To Improve Estimation Accuracy Of Rain , Justin Lapp
All Theses
The remote estimation of rainfall rate R is essential for the aviation industry, agriculture, and food warning. Radar, the current means of R estimation, is not available in much of the world. In addition, this measurement involves a level of inaccuracy. Using lightning to detect rain is a relatively inexpensive alternative to radar systems and can be done from existing satellites. Previous research has revealed correlations between lightning and rain, suggesting either that it is possible to estimate R using lightning, or that it is possible to use it to correct for a portion of the radar inaccuracies. These correlations …
Performance Of Serial, Matched-Filter Packet Acquisition Algorithms With A Preamble-Sequence Acceptance Criterion, Javier Schloemann
Performance Of Serial, Matched-Filter Packet Acquisition Algorithms With A Preamble-Sequence Acceptance Criterion, Javier Schloemann
All Theses
In this thesis, we consider two methods to improve the acquisition performance of a packet radio system that uses serial, matched-filter acquisition: an adaptive acquisition threshold, and an acceptance criterion for the system's preamble sequences. Each packet transmission includes a fixed-length acquisition preamble, and the preamble sequence used in packet transmissions is changed at predetermined times based on a sequence-generation algorithm. It is shown that acquisition performance depends largely on the sidelobe energy of the preamble sequence, the acquisition threshold, and the signal-to-noise ratio.
The first method uses a threshold-scaling technique to account for the variation in the signal-to-noise ratio. …
Approaches To Mitigate The Impact Of Dissolved Organic Matter On The Adsorption Of Synthetic Organic Contaminants By Activated Carbon, Abhishek Yadav
Approaches To Mitigate The Impact Of Dissolved Organic Matter On The Adsorption Of Synthetic Organic Contaminants By Activated Carbon, Abhishek Yadav
All Theses
The main objective of this study was to conduct a systematic investigation of various approaches to mitigate the competition of dissolved organic matter (DOM) on the adsorption of synthetic organic contaminants (SOCs) by activated carbons. TCE and atrazine were selected as the target SOCs because they are known to adsorb in different pore size regions. TCE adsorbs in the primary micropore region (i.e., <10 ) which is inaccessible to the majority of the DOM components, while atrazine adsorbs in the secondary micropore region (i.e., 10-20 ) which is partially accessible to some DOM components. The adsorbents used in this study consisted of four activated carbons (OLC, CRC, F400He, and HD4000ST) and one activated carbon fiber (ACF: ACF10). All sorbents were basic and hydrophobic in nature and represented a set of activated carbons with gradually widening pore size distribution, from the extremely microporous carbons (ACF10 and OLC) to carbons with some amount of mesopores (CRC and F400He) and finally a predominantly mesoporous (HD4000ST) carbon.
Isotherms were performed as single solute and after preloading with a dissolved organic matter (5 mg DOC/L and 20 mg DOC/L) for both TCE and atrazine and using the five activated carbons. Single solute isotherm results showed …
An In Vitro Evaluation Of Dbm As A Tissue Engineered Scaffold, Stephanie Arnold
An In Vitro Evaluation Of Dbm As A Tissue Engineered Scaffold, Stephanie Arnold
All Theses
Over 500,000 bone graft procedures are performed each year in the United States. Bone grafting involves a surgical procedure to replace missing bone. Problems can arise with donor and defect sites during and after surgery, sometimes resulting in poor clinical results. The development and optimization of bone graft substitutes via a tissue engineering approach could markedly improve bone graft surgical outcome. Demineralized bone matrix (DBM), a bone graft material, is currently used in a clinical setting but has variable success rates.
The primary objective of the research presented in this thesis was to assess the cellular activity of D1 mouse …
Fabrication And Characterization Of Cu/4h-Sic Schottky Diodes, Ruth Solomon
Fabrication And Characterization Of Cu/4h-Sic Schottky Diodes, Ruth Solomon
All Theses
Copper Schottky contacts to n-type 4H Silicon Carbide with nickel ohmic contacts were fabricated. The electrical and physical characteristics of these Schottky diodes were analyzed and the results are presented. I-V measurements revealed two sets of characteristics, one indicating nearly ideal Schottky behavior and the other exhibiting regions with two barrier heights. The reason for this observed phenomenon was studied and attributed to the in-homogeneity of the Silicon Carbide surface. The I-V and C-V characteristics were used to extract the electrical parameters, which include barrier height, ideality factor, reverse saturation current density, and doping concentration. The measured barrier height was …
Development Of A Microscopic Moirž Interferometry System, Jeremy Brougher
Development Of A Microscopic Moirž Interferometry System, Jeremy Brougher
All Theses
The human tooth is an amazing structure that is worthy of detailed research and analysis. For over half a century, various tests have been conducted to acquire more information about the structural and material properties of dentin, enamel, and the dentin-enamel junction. Unfortunately, variations still exist in the experimental results, even in the most recently collected data. The primary focus of the majority of material property testing on human teeth has been hardness testing utilizing indentation and nanoindentation analysis. However, several limitations still exist with the indentation technique. Thus, the moirŽ fringe analysis method, specifically microscopic moirŽ interferometry, has been …
Advanced Thermal Management For Internal Combustion Engines, Thomas Mitchell
Advanced Thermal Management For Internal Combustion Engines, Thomas Mitchell
All Theses
The automotive cooling system has unrealized potential to improve internal combustion engine performance through enhanced coolant temperature control and reduced parasitic losses. Advanced automotive thermal management systems use controllable actuators (e.g., smart thermostat valve, variable speed water pump, and electric radiator fan) in place of conventional mechanical cooling system components to improve engine temperature tracking over most operating ranges. To optimize advanced cooling system performance, the electro-mechanical actuators must work in harmony to control engine temperature. The design and placement of cooling components should also be considered when attempting to maximize the performance.
In this research project, two distinct vehicle …
An Investigation Of Nonlinear Estimation And System Design For Mechatronic Systems, Tim Hughes
An Investigation Of Nonlinear Estimation And System Design For Mechatronic Systems, Tim Hughes
All Theses
This thesis is a collection of two projects in which the author was involved during his master's degree program. The first project involves the estimation of 3D Euclidean coordinates of features from 2D images. A 3D Euclidean position estimation strategy is developed for a static object using a single moving camera whose motion is known. This Euclidean depth estimator has a very simple mathematical structure and is easy to implement. Numerical simulations and experimental results using a mobile robot in an indoor environment are presented to illustrate the performance of the algorithm. The second section describes the design of a …
Viability, Functionality, And Genetic Assessment Of Cells After Laser Guidance, Tabitha Rosenbalm
Viability, Functionality, And Genetic Assessment Of Cells After Laser Guidance, Tabitha Rosenbalm
All Theses
We systematically vary the controllable laser parameters, namely, wavelength, intensity, and exposure time of the laser on single cells to clearly establish laser parameters that allow negligible cell damage with significant cellular position control. To accomplish this goal, embryonic day 7 (E7) chick forebrains neurons were cultured with control and test cells selected one hour after seeding to allow attachment, at which time test cells were subjected to the laser. Cells were imaged at 4, 12, 24, and 36 hours after laser exposure to evaluate viability and functionality by using the Live/Dead Viability Cytotoxicity Kit (Molecular Probes L3224) and measuring …
Software Development For Mechatronics Systems: Simulation Of Multiple Uav Navigation And Device Driver Interface For The Q4 Data Acquisition Card, Ninad Pradhan
All Theses
Mechatronics systems are often a close interleaving of different aspects of hardware, software, control and mechanical design. Two such aspects are delved into in greater detail for this thesis, both related to software development.
Simulations are used to know the practical conditions under which a control design is effective. The system simulated in this case was a multiple vehicle system, where the vehicles navigated from source to a destination configuration avoiding two different kinds of obstacles.
Post simulation, a system is implemented using hardware and tested using an experimental setup. Data Acquisition Boards such as the Quanser Q4 are used …
Design And Development Of An In-House Scanning Tunneling Microscope System, Esvar Subramanian
Design And Development Of An In-House Scanning Tunneling Microscope System, Esvar Subramanian
All Theses
ABSTRACT
The invention of Scanning Tunneling Microscope (STM) by Binnig and Rohrer in 1982 eliminated the use of optical lenses and replaced the conventional optical microscopes with a new class of microscopes called the Scanning Probe Microscopes (SPM). Because of their unique characteristics such as higher resolution and acquisition of nano level images without affecting the physical properties of the sample, they have found wide applications in a variety of scientific disciplines such as biology, material science and electrochemistry. After considerable advancements in instrumentation, the STM has evolved as a nanomanipulation and nanofabrication tool. It operates in two modes: constant …
An Efficient Analysis Of Vertical Dipole Antennas Above A Lossy Half-Space , Yongfeng Huang
An Efficient Analysis Of Vertical Dipole Antennas Above A Lossy Half-Space , Yongfeng Huang
All Theses
The electromagnetic modeling of radiation by vertical dipole antennas above a lossy half-space has become an important subject due to many applications where these dipoles are involved. The modeling often encounters Sommerfeld-type integrals that are normally highly oscillatory with poor convergence. Recently, an efficient computation of the electric field radiated by an infinitesimal electric dipole above a lossy half-space has been reported, in which the Sommerfeld-type integrals are reduced to rapidly-converging integrals. Taking advantage of such efficiently-calculated electric field and using it as the Green's function, in this thesis, an electric field integral equation (EFIE) is formulated for the analysis …
Minimum Sample Size Needed To Construct Cushion Curves Based On The Stress-Energy Method, Patricia Marcondes
Minimum Sample Size Needed To Construct Cushion Curves Based On The Stress-Energy Method, Patricia Marcondes
All Theses
Cushion curves are graphical tools used by protective package designers to evaluate and choose foamed cushioning materials. Thousands of samples and hundreds of laboratory hours are needed to produce a full set of cushion curves according to the ASTM procedure D 1596. The stress-energy method considerably reduces the number of samples needed to construct cushion curves for closed-cell cushioning materials. Consequently the laboratory and data analysis time are reduced as well.
The stress-energy method was used to find the minimum sample size needed to construct cushion curves for closed-cell cushioning materials. A reference set of data collected for ARCEL Resin¨ …
Optimal Placement Of Metal Foils In Ultrasonic Consolidation Process, Raji Rexavier
Optimal Placement Of Metal Foils In Ultrasonic Consolidation Process, Raji Rexavier
All Theses
Ultrasonic Consolidation is a combination of additive and subtractive
manufacturing processes resulting in considerable material waste. This waste is a
function of the geometry of the part being manufactured and of the relative
placement of the layer with respect to the metal bands. Thus the waste may be
minimized by careful choice of the layer angle and offset from the original
position.
Previous work done in this field had developed an automated algorithm which
optimally places and orients the individual slices of the STL file of the artifact
being manufactured. However, the problem was solved on a 2-D scale and …
Characterization Of The Ibc Technologies Superlig¨ 620 Solid Phase Extraction Resin With Applications For Automated Process Monitoring, John Clements
Characterization Of The Ibc Technologies Superlig¨ 620 Solid Phase Extraction Resin With Applications For Automated Process Monitoring, John Clements
All Theses
Characterization of the IBC Advanced Technologies SuperLig¨ 620 solid phase extraction resin was performed in order to develop an automated strontium-90 process monitor. The main focus was on strontium separation from barium, with the goal of developing an automated separation process for strontium-90 in Hanford high-level tank wastes. High-level waste tanks contain significant cesium-137 activities, of which barium daughters are of great concern as interferences to strontium quantification. A number of complexants were studied in a series of batch distribution coefficient experiments, as SuperLig¨ 620 was not previously known to elute strontium in typical mineral acids. The optimal separation was …
Soar Checkers - An Intelligent Checkers Playing Agent In Soar, Jithu Menon
Soar Checkers - An Intelligent Checkers Playing Agent In Soar, Jithu Menon
All Theses
The classic board game of checkers is ideally suited for research in AI game-playing programs or agents. The objective behind Soar Checkers is to investigate if it is possible to create an agent-based game playing system that would beat novices with ease and at least challenge advanced novice to intermediate-level players by designing a rules-based expert system whose knowledge base consists of nothing more than the rules of checkers, and a set of guidelines for game-play based on good strategy. Soar was chosen as the platform for building this agent because it came built-in with features that facilitate creating rules-based …
Energy Absorption Of Sine Wave Beams Subjected To Axial Impact Loading, Robert Smith
Energy Absorption Of Sine Wave Beams Subjected To Axial Impact Loading, Robert Smith
All Theses
Energy absorbers ideally remove kinetic energy efficiently and reliably while minimizing force magnitudes felt on the moving body. Until now, energy absorber design has concentrated on thin-walled prismatic tubes and tapered tubes. Sine wave beams (SWB) have been previously investigated as energy absorbers under lateral impacting situations only. This thesis investigates the energy absorption of the SWB under axial impact. FE models simulated the energy absorbing response of the SWB. Parametric analyses were performed using the structure's thickness, the web amplitude, and the period number of the web. The SWB's performance is evaluated and then compared to the prismatic structures. …
Evaluation Of Different Contra-Flow Strategies For Hurricane Evacuation In Charleston, South Carolina, Liz Stephen
Evaluation Of Different Contra-Flow Strategies For Hurricane Evacuation In Charleston, South Carolina, Liz Stephen
All Theses
The number of category four and five hurricanes has nearly doubled over the past decade. Charleston, the second most populous city in South Carolina, is located on a very low peninsula, making it susceptible to floods during hurricanes and storm surges. In the event of a hurricane, the population at-risk must be evacuated to safety as quickly as possible. The Interstate system is the primary mode to evacuate at-risk population out of Charleston. Effective traffic management strategies are needed to manage the significant increase in demand on highways during the evacuation and contra-flowing traffic has been applied as a strategy …
Extrapolation Of Time And Frequency Responses Of Resonant Antennas Using Damped Sinusoids And Orthogonal Polynomials, James Frye
All Theses
An extrapolation technique is presented which reduces the computational demands of obtaining a wide-band electromagnetic response from a resonant antenna using traditional computational methods. It has been shown that a wide-band response can be extrapolated by fitting early-time and low-frequency data as a summation of orthogonal polynomials. However, because the polynomials provide compact time support, representation of long time responses intrinsic to resonant structures in practice proves inefficient and can lead to numerical instabilities. This thesis outlines incorporating damped sinusoids to efficiently and reliably extrapolate time and frequency responses of resonant antennas due to a wide-band source. A genetic algorithm …
Linear And Non-Linear Control Of A Quadrotor Uav, Andrew Neff
Linear And Non-Linear Control Of A Quadrotor Uav, Andrew Neff
All Theses
This thesis describes two controllers designed specifically for a quadrotor helicopter unmanned aerial vehicle (UAV). A linear controller and a non-linear controller are discussed for use on the quadrotor helicopter using feedback that is obtained from microelectromechanical systems and GPS.
The linear controller is an orientation based PID controller that controls the angles of the quadrotor UAV. The controller was first simulated and the results displayed graphically using FlightGear. Experiments were conducted using this controller on a DraganFlyer X-Pro quadrotor helicopter to prove the proposed method used for closing the feedback loop.
The non-linear controller is developed using Lyapunov stability …
Modeling Requirements Propagation To Generate Solutions For Minimizing Mass, Thulasiram Ezhilan
Modeling Requirements Propagation To Generate Solutions For Minimizing Mass, Thulasiram Ezhilan
All Theses
This thesis investigates the issue of weight reduction in moderately complex systems by addressing how to cascade the requirements to the individual components. Though mass can be reduced using different techniques such as material substitution or structural optimization; a systematic method for allocating mass as a function of requirements is necessary to provide novel alternate solutions that enable reduction of mass of the system while satisfying the requirements and tests governing them. Such a method can be developed by exploring different aspects of achieving weight reduction through change propagation in the parameters/elements governing the system. Though efforts have been made …
Machinability And Microstructure Stability During The Machining Of Pure Copper And Titanium Processed By Equal Channel Angular Pressing, Mason Morehead
Machinability And Microstructure Stability During The Machining Of Pure Copper And Titanium Processed By Equal Channel Angular Pressing, Mason Morehead
All Theses
For ultrafine grained materials (containing microstructures of 100-300 nm) to be manufactured and used in industry, machining research is needed to form and shape these materials into their final dimensions. Because of their high internal energy, UFG materials are known to have microstructures which are susceptible to undesirable changes at low temperatures. In this study, pure ultrafine grained copper and titanium as well as their respective coarse grained (CG) counterparts were tested for their relative machinability and microstructure stability through lathe turning. To evaluate the machinability cutting forces, tool wear, chip morphology, and surface roughness were studied using different cutting …