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Articles 2131 - 2160 of 4694
Full-Text Articles in Engineering
Machine Learning Methods For Medical And Biological Image Computing, Rongjian Li
Machine Learning Methods For Medical And Biological Image Computing, Rongjian Li
Computer Science Theses & Dissertations
Medical and biological imaging technologies provide valuable visualization information of structure and function for an organ from the level of individual molecules to the whole object. Brain is the most complex organ in body, and it increasingly attracts intense research attentions with the rapid development of medical and bio-logical imaging technologies. A massive amount of high-dimensional brain imaging data being generated makes the design of computational methods for efficient analysis on those images highly demanded. The current study of computational methods using hand-crafted features does not scale with the increasing number of brain images, hindering the pace of scientific discoveries …
Possible Sources And Impacts Of Biochar Water Extractable Organic Compounds On Aquatic Microorganisms, Cameron Russell Smith
Possible Sources And Impacts Of Biochar Water Extractable Organic Compounds On Aquatic Microorganisms, Cameron Russell Smith
Chemistry & Biochemistry Theses & Dissertations
Smokeless biomass pyrolysis with application of biochar as a soil amendment could be a significant approach for carbon sequestration to possibly control climate change for energy and environmental sustainability. If biochar were to be utilized as a soil amendment and a carbon sequestration agent at Gt C scales, the release of potentially toxic compounds into soils and associated hydrological systems, through soil rainwater runoff and leaching, might have negative consequences, in both agro-ecosystems and aquatic environmental systems. Therefore, the main focus of this dissertation was to study the sources and chemical composition of biochar water extractable (soluble) organic compounds and …
A Hybrid Tabu/Scatter Search Algorithm For Simulation-Based Optimization Of Multi-Objective Runway Operations Scheduling, Bulent Soykan
A Hybrid Tabu/Scatter Search Algorithm For Simulation-Based Optimization Of Multi-Objective Runway Operations Scheduling, Bulent Soykan
Engineering Management & Systems Engineering Theses & Dissertations
As air traffic continues to increase, air traffic flow management is becoming more challenging to effectively and efficiently utilize airport capacity without compromising safety, environmental and economic requirements. Since runways are often the primary limiting factor in airport capacity, runway operations scheduling emerge as an important problem to be solved to alleviate flight delays and air traffic congestion while reducing unnecessary fuel consumption and negative environmental impacts. However, even a moderately sized real-life runway operations scheduling problem tends to be too complex to be solved by analytical methods, where all mathematical models for this problem belong to the complexity class …
Carbon Deposition During Oxygen Production Using High Temperature Electrolysis And Mitigation Methods, Timothy Adam Bernadowski
Carbon Deposition During Oxygen Production Using High Temperature Electrolysis And Mitigation Methods, Timothy Adam Bernadowski
Mechanical & Aerospace Engineering Theses & Dissertations
Carbon dioxide in the Martian atmosphere can be converted to oxygen during high temperature electrolysis for use in life-support and fuel systems on manned missions to the red planet. During electrolysis of carbon dioxide to produce oxygen, carbon can deposit on the electrolysis cell resulting in lower efficiency and possibly cell damage. This would be detrimental, especially when the oxygen product is used as the key element of a space life support system. In this thesis, a theoretical model was developed to predict hazardous carbon deposition conditions under various operating conditions within the Martian atmosphere. The model can be used …
Simulation, Measurement, And Emulation Of Photovoltaic Modules Using High Frequency And High Power Density Power Electronic Circuits, Yunas Erkaya
Electrical & Computer Engineering Theses & Dissertations
The number of solar photovoltaic (PV) installations is growing exponentially, and to improve the energy yield and the efficiency of PV systems, it is necessary to have correct methods for simulation, measurement, and emulation. PV systems can be simulated using PV models for different configurations and technologies of PV modules. Additionally, different environmental conditions of solar irradiance, temperature, and partial shading can be incorporated in the model to accurately simulate PV systems for any given condition.
The electrical measurement of PV systems both prior to and after making electrical connections is important for attaining high efficiency and reliability. Measuring PV …
Global Sensitivity Analysis Of Mat Foundation Behavior By Using Finite Element Modeling, Yang Zhao
Global Sensitivity Analysis Of Mat Foundation Behavior By Using Finite Element Modeling, Yang Zhao
Civil & Environmental Engineering Theses & Dissertations
Mat foundation is used mostly for high-rise buildings and, since the demand for high- rise buildings is growing, having extensive understanding of mat foundation behavior leads us into more efficient structural design. Mat foundation behaviors are affected mostly by soil’s materials properties, foundation size, and thickness and loading conditions. In this study, the sensitivity of mat foundation structural responses to some of the design parameters are evaluated. Sobol decomposition, which is a variance-based technique, is used to perform the global sensitivity analysis. In this study, Patran, a finite element-based software, is used for modeling and simulations.
Approximate flexible method is …
A Simulation-Based Layered Framework Framework For The Development Of Collaborative Autonomous Systems, Ioannis Sakiotis
A Simulation-Based Layered Framework Framework For The Development Of Collaborative Autonomous Systems, Ioannis Sakiotis
Computational Modeling & Simulation Engineering Theses & Dissertations
The purpose of this thesis is to introduce a simulation-based software framework that facilitates the development of collaborative autonomous systems. Significant commonalities exist in the design approaches of both collaborative and autonomous systems, mirroring the sense, plan, act paradigm, and mostly adopting layered architectures. Unfortunately, the development of such systems is intricate and requires low-level interfacing which significantly detracts from development time. Frameworks for the development of collaborative and autonomous systems have been developed but are not flexible and center on narrow ranges of applications and platforms. The proposed framework utilizes an expandable layered structure that allows developers to define …
Microbubble Generation By Piezoelectric Transducers For Biomedical Studies, Mohammed Alkhazal
Microbubble Generation By Piezoelectric Transducers For Biomedical Studies, Mohammed Alkhazal
Electrical & Computer Engineering Theses & Dissertations
Bubbles induced by blast waves or shocks are speculated as the major cause of damage in biological cells in mild traumatic brain injuries (TBI). Microbubble collapse was found to induce noticeable cell detachment from the cell substrate, changes in focal adhesion, and biomechanics. To better understand the bubble mechanism, a system needs to be constructed which allows clear differentiation on the impact of bubbles from that of shocks. Such a generator needs to be low profile in order to place under a microscope. A piezoelectric transducer system was designed to meet the need. The system uses either a flat or …
Bunch Splitting Simulations For The Jleic Ion Collider Ring, R. Gamage, T. Satogata
Bunch Splitting Simulations For The Jleic Ion Collider Ring, R. Gamage, T. Satogata
Physics Faculty Publications
We describe the bunch splitting strategies for the proposed JLEIC ion collider ring at Jefferson Lab. This complex requires an unprecedented 9:6832 bunch splitting, performed in several stages. We outline the problem and current results, optimized with ESME including general parameterization of 1:2 bunch splitting for JLEIC parameters.
Panel - Resilience Design: Dewberry, Jane Sibley Frantz
Panel - Resilience Design: Dewberry, Jane Sibley Frantz
May 6, 2016: Planning for Resilience in Hampton Roads
No abstract provided.
Lessons From Rebuild By Design, Tara Eisenberg
Lessons From Rebuild By Design, Tara Eisenberg
May 6, 2016: Planning for Resilience in Hampton Roads
No abstract provided.
Panel - Resilience Design: Clark Nexsen, Paul Battaglia
Panel - Resilience Design: Clark Nexsen, Paul Battaglia
May 6, 2016: Planning for Resilience in Hampton Roads
No abstract provided.
Panel - Resilience Design: Arcadis, Kyle Graham
Panel - Resilience Design: Arcadis, Kyle Graham
May 6, 2016: Planning for Resilience in Hampton Roads
No abstract provided.
A 'Tissue Model' To Study The Barrier Effects Of Living Tissues On The Reactive Species Generated By Surface Air Discharge, Tongtong He, Dingxin Liu, Han Xu, Zhichao Liu, Dehui Xu, Dong Li, Qiosong Li, Mingzhe Rong, Michael G. Kong
A 'Tissue Model' To Study The Barrier Effects Of Living Tissues On The Reactive Species Generated By Surface Air Discharge, Tongtong He, Dingxin Liu, Han Xu, Zhichao Liu, Dehui Xu, Dong Li, Qiosong Li, Mingzhe Rong, Michael G. Kong
Bioelectrics Publications
Gelatin gels are used as surrogates of human tissues to study their barrier effects on incoming reactive oxygen and nitrogen species (RONS) generated by surface air discharge. The penetration depth of nitrite into gelatin gel is measured in real time during plasma treatment, and the permeabilities of nitrite, nitrate, O3 and H2O2 through gelatin gel films are quantified by measuring their concentrations in the water underneath such films after plasma treatment. It is found that the penetration speed of nitrite increases linearly with the mass fraction of water in the gelatin gels, and the permeabilities of …
Experimental Assessment Of Mouse Sociability Using An Automated Image Processing Approach, Frency Varghese, Jessica A. Burket, Andrew D. Benson, Stephen I. Deutsch, Christian W. Zemlin
Experimental Assessment Of Mouse Sociability Using An Automated Image Processing Approach, Frency Varghese, Jessica A. Burket, Andrew D. Benson, Stephen I. Deutsch, Christian W. Zemlin
Electrical & Computer Engineering Faculty Publications
Mouse is the preferred model organism for testing drugs designed to increase sociability. We present a method to quantify mouse sociability in which the test mouse is placed in a standardized apparatus and relevant behaviors are assessed in three different sessions (called session I, II, and III). The apparatus has three compartments (see Figure 1), the left and right compartments contain an inverted cup which can house a mouse (called “stimulus mouse”). In session I, the test mouse is placed in the cage and its mobility is characterized by the number of transitions made between compartments. In session II, a …
Proceedings, Msvscc 2016, Old Dominion University, Department Of Modeling, Simulation & Visualization Engineering, Old Dominion University, Virginia Modeling, Analysis & Simulation Center
Proceedings, Msvscc 2016, Old Dominion University, Department Of Modeling, Simulation & Visualization Engineering, Old Dominion University, Virginia Modeling, Analysis & Simulation Center
Modeling, Simulation and Visualization Student Capstone Conference
Proceedings of the 10th Annual Modeling, Simulation & Visualization Student Capstone Conference held on April 14, 2016 at VMASC in Suffolk, Virginia.
Section Abstracts: Biomedical And General Engineering
Section Abstracts: Biomedical And General Engineering
Virginia Journal of Science
Abstracts of the Biomedical and General Engineering Section for the 94th Annual Virginia Academy of Science Meeting, May 18-20, 2016, at University of Mary Washington, Fredericksburg, VA.
Membrane Channel Gene Expression In Human Costal And Articular Chondrocytes, A. Asmar, R. Barrett-Jolley, A. Werner, R. Kelly Jr., M. Stacey
Membrane Channel Gene Expression In Human Costal And Articular Chondrocytes, A. Asmar, R. Barrett-Jolley, A. Werner, R. Kelly Jr., M. Stacey
Bioelectrics Publications
Chondrocytes are the uniquely resident cells found in all types of cartilage and key to their function is the ability to respond to mechanical loads with changes of metabolic activity. This mechanotransduction property is, in part, mediated through the activity of a range of expressed transmembrane channels; ion channels, gap junction proteins, and porins. Appropriate expression of ion channels has been shown essential for production of extracellular matrix and differential expression of transmembrane channels is correlated to musculoskeletal diseases such as osteoarthritis and Albers-Sch€onberg. In this study we analyzed the consistency of gene expression between channelomes of chondrocytes from human …
Secondary Electron Emission From Plasma Processed Accelerating Cavity Grade Niobium, Miloš Bašović
Secondary Electron Emission From Plasma Processed Accelerating Cavity Grade Niobium, Miloš Bašović
Mechanical & Aerospace Engineering Theses & Dissertations
Advances in the particle accelerator technology have enabled numerous fundamental discoveries in 20th century physics. Extensive interdisciplinary research has always supported further development of accelerator technology in efforts of reaching each new energy frontier.
Accelerating cavities, which are used to transfer energy to accelerated charged particles, have been one of the main focuses of research and development in the particle accelerator field. Over the last fifty years, in the race to break energy barriers, there has been constant improvement of the maximum stable accelerating field achieved in accelerating cavities. Every increase in the maximum attainable accelerating fields allowed for higher …
Concurrent Spatial Mapping Of The Viscoelastic Behavior Of Heterogeneous Soft Materials Via A Polymer-Based Microfluidic Device, Wenting Gu
Mechanical & Aerospace Engineering Theses & Dissertations
This dissertation presents a novel experimental technique, namely concurrent spatial mapping (CSM), for measuring the viscoelastic behavior of heterogeneous soft materials via a polymer-based microfluidic device. Comprised of a compliant polymer microstructure and an array of electrolyte-enabled distributed resistive transducers, the microfluidic device detects both static and dynamic distributed loads. Distributed loads deform the polymer microstructure and are recorded as resistance changes at the locations of the transducers.
The CSM technique identifies the elastic modulus of soft materials by applying a precisely controlled indentation depth using a rigid probe to a sample placed on the device. The spatially-varying elastic modulus …
Investigating The Relationship Between Latent Driving Patterns And Traffic Safety Using Smartphone-Based Mobile Sensor Data, Kenneth Wynne
Investigating The Relationship Between Latent Driving Patterns And Traffic Safety Using Smartphone-Based Mobile Sensor Data, Kenneth Wynne
Civil & Environmental Engineering Theses & Dissertations
Crash frequency modelling has been used in the past as an attempt to quantify the expected number of crashes occurring on a certain segment of roadway given a set of variables and factors describing the roadway segment and the traffic along that segment. These models are referred to as the Safety Performance Functions (SPFs) in the Highway Safety Manual (HSM). In past studies, these SPFs have focused primarily on roadway geometric information along with limited traffic exposure data such as traffic volume. Alternate data sources for probe vehicle data are increasingly available and this research sought to exploit this new …
Sparse Coding Based Feature Representation Method For Remote Sensing Images, Ender Oguslu
Sparse Coding Based Feature Representation Method For Remote Sensing Images, Ender Oguslu
Electrical & Computer Engineering Theses & Dissertations
In this dissertation, we study sparse coding based feature representation method for the classification of multispectral and hyperspectral images (HSI). The existing feature representation systems based on the sparse signal model are computationally expensive, requiring to solve a convex optimization problem to learn a dictionary. A sparse coding feature representation framework for the classification of HSI is presented that alleviates the complexity of sparse coding through sub-band construction, dictionary learning, and encoding steps. In the framework, we construct the dictionary based upon the extracted sub-bands from the spectral representation of a pixel. In the encoding step, we utilize a soft …
Low-Temperature Artificial Maturation Studies Of Type Ii And Type Iii Kerogens: Implications For Biogenic Gas Production, Albert Willy Nguena Kamga
Low-Temperature Artificial Maturation Studies Of Type Ii And Type Iii Kerogens: Implications For Biogenic Gas Production, Albert Willy Nguena Kamga
Chemistry & Biochemistry Theses & Dissertations
Ancient organic matter (OM) in shales and coals, known mainly as Type II and Type III OM are known to produce both biogenic, thermogenic gas and oil. In this dissertation, mild artificial maturation, via closed system pyrolysis, is employed to determine the thermal reactivity of Type II and Type III OM beyond diagenesis. We select three Type II kerogens: i) Type II kerogen isolated from recent cores (3.3 Ma, Ro = 0.28) recovered from an upwelling basin in Namibia, Africa referred to as ODP Sediment, ii) Type II-S isolated from sediments (150 Ma, Ro = 0.38) recovered from an outcrop …
Impacts Of Operating Parameters On Extracellular Polymeric Substances Production In A High Rate Activated Sludge System With Low Solids Retention Times, Matthew S. Elliot
Impacts Of Operating Parameters On Extracellular Polymeric Substances Production In A High Rate Activated Sludge System With Low Solids Retention Times, Matthew S. Elliot
Civil & Environmental Engineering Theses & Dissertations
The Adsorption/Bio-oxidation (A/B) process accomplishes carbon capture via bio-flocculation in the adsorption stage (A-stage) to maximize energy recovery while simultaneously providing an optimal carbon to nitrogen (C/N) ratio for denitrification in the Bio-oxidation stage (B-Stage). The present study evaluated the influence of the solids retention time (SRT), dissolved oxygen (DO) concentration, and production of extracellular polymeric substances (EPS) on bio-flocculation and subsequent carbon capture using a pilot-scale A-stage process. A mixed liquor suspended solids (MLSS)-based control strategy was implemented to manage carbon capture by maintaining a constant MLSS concentration of 3,000 mg/L in response to diurnal variations in organic loading. …
Long-Term Quantitative Study Of Wind-Tunnel Balance Calibrations Across Multiple Calibration Systems, Ryan James Callahan
Long-Term Quantitative Study Of Wind-Tunnel Balance Calibrations Across Multiple Calibration Systems, Ryan James Callahan
Mechanical & Aerospace Engineering Theses & Dissertations
Internal strain-gauge balances are multi-dimensional force transducers widely employed in wind tunnels to obtain accurate aerodynamic force and moment data on an aircraft model. Balances are calibrated periodically to assure measurement accuracy. The calibration provides a mathematical model relating the forces applied to the balance and the output signal from the balance. Currently, there are multiple types of internal strain-gauge balances used in wind-tunnel testing as well as multiple methods by which balances are calibrated. Because of the differences in the hardware and methodologies used to calibrate a wind-tunnel balance, it is hard to quantify the differences seen between the …
Carbon And Boron Nitride Nanotube Fabricated Supercapacitors, Derek Christian Demuth
Carbon And Boron Nitride Nanotube Fabricated Supercapacitors, Derek Christian Demuth
Electrical & Computer Engineering Theses & Dissertations
The fabrication of supercapacitor devices consisting of boron nitride nanotubes (BNNTs) and carbon nanotubes (CNTs) has great theoretical capabilities of high specific capacitance, energy density, and power density. Various methods of dispersion and deposition are utilized to optimize such supercapacitors with BNNTs and CNTs, and also to produce devices with only CNTs to use as a benchmark. In addition to capacitance measurements, BNNTs that were exposed to nitric acid were compared to fabricated devices without acid exposure.
Dispersion has been accomplished through the trial of many solvents and surfactants for both CNTs and BNNTs. Deposition techniques that are utilized rely …
Thin Film Studies Toward Improving The Performance Of Accelerator Electron Sources, Md Abdullah Al Mamun
Thin Film Studies Toward Improving The Performance Of Accelerator Electron Sources, Md Abdullah Al Mamun
Mechanical & Aerospace Engineering Theses & Dissertations
Future electron accelerators require DC high voltage photoguns to operate beyond the present state of the art to conduct new experiments that require ultra-bright electron beams with high average current and higher bunch charge. To meet these demands, the accelerators must demonstrate improvements in a number of photogun areas including vacuum, field emission elimination in high voltage electrodes, and photocathodes. This dissertation illustrates how these improvements can be achieved by the application of suitable thin-films to the photogun structure for producing ultra-bright electron beams.
This work is composed of three complementary studies. First, the outgassing rates of three nominally identical …
Experimental Analysis Of Turbulent Structures And The Effects Of Non-Equilibrium On An Axial Vortex, Michael P. Thompson
Experimental Analysis Of Turbulent Structures And The Effects Of Non-Equilibrium On An Axial Vortex, Michael P. Thompson
Mechanical & Aerospace Engineering Theses & Dissertations
Examples of the axial vortex include, dust devils, trailing line aircraft wake vortices, and tornadoes. Some of these vortices can prove hazardous to individuals and property. This necessitates that studies be conducted to understand their structure and to attempt to develop mathematical models of the flow physics involved. A wide variety of experimental techniques have been used in the past to study the vortex, with flow visualization and hotwire anemometry being chosen for this experiment. There have been many inadequate mathematical models proposed in the past. The experimental results obtained were compared to the work of Ash, Zardadkhan and Zuckerwar …
Design And Implementation Of A Virtual Team Collaboration System, Syed Ehsan
Design And Implementation Of A Virtual Team Collaboration System, Syed Ehsan
Engineering Management & Systems Engineering Theses & Dissertations
This paper analyzes a newly developed virtual team collaboration site and compares this application with the currently in use team collaboration tool created using a Google site. Various tests that are essential for a web service to function properly are performed to compare the applications. The tests are aimed to find any issues with the applications and identify if Teamboard ODU, the newly developed application, can perform better than the Google site. We test for speed, performance, usability, functionality and also explore the methodology used to develop the application. These test results allow us to make an informed assumption about …
Idpal - Input Decoupled Partially Adiabatic Logic Family: Theory And Implementation Of Side-Channel Attack Resistant Circuits, Matthew Edward Mcallister
Idpal - Input Decoupled Partially Adiabatic Logic Family: Theory And Implementation Of Side-Channel Attack Resistant Circuits, Matthew Edward Mcallister
Electrical & Computer Engineering Theses & Dissertations
The Input Decoupled Partially Adiabatic Logic (IDPAL) family was developed by Cutitaru to consume less power than other logic families as well as producing a resistance to side-channel attacks. With modifications made to IDPAL, the side-channel attack resistance is being revisited and quantified. The three logic families are compared in the work are CMOS, 2N2P, and IDPAL. An AND/NAND gate was created using each logic family and compared with two tests: 1) a simulated side-channel attack and 2) an energy analysis. In this work, a side-channel attack is the ability to predict the inputs of a logic circuit based on …