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2018

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Articles 4321 - 4350 of 8951

Full-Text Articles in Engineering

Simulation-Based Analysis And Optimization Of The United States Army Performance Appraisal System., Lee A. Evans May 2018

Simulation-Based Analysis And Optimization Of The United States Army Performance Appraisal System., Lee A. Evans

Electronic Theses and Dissertations

In this dissertation, a discrete event simulation framework is considered to replicate the dynamics, structure, and regulatory constraints placed on the officers in the U.S. Army. Using performance appraisal data provided by the United States Army Human Resources Command, we create a multi-objective response function that quantifies the human behavior associated with evaluating subordinates. Utilizing simulation-optimization techniques for model validation enables estimating unknown input parameters, such as human behavior, based on historical data. Furthermore, the model allows users to analyze the effects of current constraints on the evaluation system and the effects of proposed personnel policy changes.The effectiveness of the …

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Challenges In Flexible Microsystem Manufacturing : Fabrication, Robotic Assembly, Control, And Packaging., Danming Wei May 2018

Challenges In Flexible Microsystem Manufacturing : Fabrication, Robotic Assembly, Control, And Packaging., Danming Wei

Electronic Theses and Dissertations

Microsystems have been investigated with renewed interest for the last three decades because of the emerging development of microelectromechanical system (MEMS) technology and the advancement of nanotechnology. The applications of microrobots and distributed sensors have the potential to revolutionize micro and nano manufacturing and have other important health applications for drug delivery and minimal invasive surgery. A class of microrobots studied in this thesis, such as the Solid Articulated Four Axis Microrobot (sAFAM) are driven by MEMS actuators, transmissions, and end-effectors realized by 3-Dimensional MEMS assembly. Another class of microrobots studied here, like those competing in the annual IEEE Mobile …

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A 3d Numerical Analysis Of The Railway To Compare The Performance Of The Granular And Asphalt Trackbeds., Thammapot Wattanapanalai May 2018

A 3d Numerical Analysis Of The Railway To Compare The Performance Of The Granular And Asphalt Trackbeds., Thammapot Wattanapanalai

Electronic Theses and Dissertations

In the last two decades, trains have been developed either to carry heavy weight of cargo or for high-speed rail transport. Nonetheless, track structure, have not been improved adequate to support the extra loads or dynamic vibrations of high-speed trains. As a result, the performance of track will be affected from heavy freight or high-speed trains. In the long term it results in trackbed damage by increasing the subgrade and ballast displacement. Besides, it negatively affects the performance of the locomotives. Therefore, alternative subballast, should be introduced to reduce the stress and deformation of the track under dynamic or heavy …

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Maintainability Analysis Of Mining Trucks With Data Analytics., Abdulgani Kahraman May 2018

Maintainability Analysis Of Mining Trucks With Data Analytics., Abdulgani Kahraman

Electronic Theses and Dissertations

The mining industry is one of the biggest industries in need of a large budget, and current changes in global economic challenges force the industry to reduce its production expenses. One of the biggest expenditures is maintenance. Thanks to the data mining techniques, available historical records of machines’ alarms and signals might be used to predict machine failures. This is crucial because repairing machines after failures is not as efficient as utilizing predictive maintenance. In this case study, the reasons for failures seem to be related to the order of signals or alarms, called events, which come from trucks. The …

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Segmentation, Tracking, And Kinematics Of Lung Parenchyma And Lung Tumors From 4d Ct With Application To Radiation Treatment Planning., Jungwon Cha May 2018

Segmentation, Tracking, And Kinematics Of Lung Parenchyma And Lung Tumors From 4d Ct With Application To Radiation Treatment Planning., Jungwon Cha

Electronic Theses and Dissertations

This thesis is concerned with development of techniques for efficient computerized analysis of 4-D CT data. The goal is to have a highly automated approach to segmentation of the lung boundary and lung nodules inside the lung. The determination of exact lung tumor location over space and time by image segmentation is an essential step to track thoracic malignancies. Accurate image segmentation helps clinical experts examine the anatomy and structure and determine the disease progress. Since 4-D CT provides structural and anatomical information during tidal breathing, we use the same data to also measure mechanical properties related to deformation of …

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End-To-End Learning Framework For Circular Rna Classification From Other Long Non-Coding Rnas Using Multi-Modal Deep Learning., Mohamed Chaabane May 2018

End-To-End Learning Framework For Circular Rna Classification From Other Long Non-Coding Rnas Using Multi-Modal Deep Learning., Mohamed Chaabane

Electronic Theses and Dissertations

Over the past two decades, a circular form of RNA (circular RNA) produced from splicing mechanism has become the focus of scientific studies due to its major role as a microRNA (miR) ac tivity modulator and its association with various diseases including cancer. Therefore, the detection of circular RNAs is a vital operation for continued comprehension of their biogenesis and purpose. Prediction of circular RNA can be achieved by first distinguishing non-coding RNAs from protein coding gene transcripts, separating short and long non-coding RNAs (lncRNAs), and finally pre dicting circular RNAs from other lncRNAs. However, available tools to distinguish circular …

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Assessment And Optimization Of Environmental Systems Using Data Analysis And Simulation., Milad Ebrahimi May 2018

Assessment And Optimization Of Environmental Systems Using Data Analysis And Simulation., Milad Ebrahimi

Electronic Theses and Dissertations

For most environmental systems, specifically wastewater treatment plants and aquifers, a significant number of performance data variables are attained on a time series basis. Due to the interconnectedness of the variables, it is often difficult to assess over-arching trends and quantify temporal operational performance. The objective of this research study was to provide an effective means for comprehensive temporal evaluation of environmental systems. The proposed methodology used several multivariate data analyses and statistical techniques to present an assessment framework for the water quality monitoring programs as well as optimization of treatment plants and aquifer systems. The developed procedure considered the …

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Robust Fuzzy Clustering For Multiple Instance Regression., Mohamed Trabelsi May 2018

Robust Fuzzy Clustering For Multiple Instance Regression., Mohamed Trabelsi

Electronic Theses and Dissertations

Multiple instance regression (MIR) operates on a collection of bags, where each bag contains multiple instances sharing an identical real-valued label. Only few instances, called primary instances, contribute to the bag labels. The remaining instances are noise and outliers observations. The goal in MIR is to identify the primary instances within each bag and learn a regression model that can predict the label of a previously unseen bag. In this thesis, we introduce an algorithm that uses robust fuzzy clustering with an appropriate distance to learn multiple linear models from a noisy feature space simultaneously. We show that fuzzy memberships …

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Longitudinal Tracking Of Physiological State With Electromyographic Signals., Robert Warren Stallard May 2018

Longitudinal Tracking Of Physiological State With Electromyographic Signals., Robert Warren Stallard

Electronic Theses and Dissertations

Electrophysiological measurements have been used in recent history to classify instantaneous physiological configurations, e.g., hand gestures. This work investigates the feasibility of working with changes in physiological configurations over time (i.e., longitudinally) using a variety of algorithms from the machine learning domain. We demonstrate a high degree of classification accuracy for a binary classification problem derived from electromyography measurements before and after a 35-day bedrest. The problem difficulty is increased with a more dynamic experiment testing for changes in astronaut sensorimotor performance by taking electromyography and force plate measurements before, during, and after a jump from a small platform. A …

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A Framework For Cardio-Pulmonary Resuscitation (Cpr) Scene Retrieval From Medical Simulation Videos Based On Object And Activity Detection., Anju Panicker Madhusoodhanan Sathik May 2018

A Framework For Cardio-Pulmonary Resuscitation (Cpr) Scene Retrieval From Medical Simulation Videos Based On Object And Activity Detection., Anju Panicker Madhusoodhanan Sathik

Electronic Theses and Dissertations

In this thesis, we propose a framework to detect and retrieve CPR activity scenes from medical simulation videos. Medical simulation is a modern training method for medical students, where an emergency patient condition is simulated on human-like mannequins and the students act upon. These simulation sessions are recorded by the physician, for later debriefing. With the increasing number of simulation videos, automatic detection and retrieval of specific scenes became necessary. The proposed framework for CPR scene retrieval, would eliminate the conventional approach of using shot detection and frame segmentation techniques. Firstly, our work explores the application of Histogram of Oriented …

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Network Science Algorithms For Mobile Networks., Heba Mohamed Elgazzar May 2018

Network Science Algorithms For Mobile Networks., Heba Mohamed Elgazzar

Electronic Theses and Dissertations

Network Science is one of the important and emerging fields in computer science and engineering that focuses on the study and analysis of different types of networks. The goal of this dissertation is to design and develop network science algorithms that can be used to study and analyze mobile networks. This can provide essential information and knowledge that can help mobile networks service providers to enhance the quality of the mobile services. We focus in this dissertation on the design and analysis of different network science techniques that can be used to analyze the dynamics of mobile networks. These techniques …

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Grid-Connected Photovoltaic Systems Based On Nonlinear Control., Pablo R. Rivera May 2018

Grid-Connected Photovoltaic Systems Based On Nonlinear Control., Pablo R. Rivera

Electronic Theses and Dissertations

Nowadays, due to the high-scale penetration of photovoltaic systems, reliable and efficient grid-connected photovoltaic (PV) systems utilizing the advances of power electronics and control system technology are desirable. Thus, single-stage grid-connected photovoltaic systems, have gained attention, especially in low voltage applications. However, PV systems exhibit nonlinear behavior that could negatively affect the performance of the system if they are not adequately compensated for. In this dissertation, using the general structure for the synchronous dq0 frame, a single-stage three-phase grid-connected photovoltaic system, and a single-stage single-phase grid-connected PV system, both with a nonlinear control strategy, are developed to track the maximum …

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Multi Self-Adapting Particle Swarm Optimization Algorithm (Msapso)., Gerhard Koch May 2018

Multi Self-Adapting Particle Swarm Optimization Algorithm (Msapso)., Gerhard Koch

Electronic Theses and Dissertations

The performance and stability of the Particle Swarm Optimization algorithm depends on parameters that are typically tuned manually or adapted based on knowledge from empirical parameter studies. Such parameter selection is ineffectual when faced with a broad range of problem types, which often hinders the adoption of PSO to real world problems. This dissertation develops a dynamic self-optimization approach for the respective parameters (inertia weight, social and cognition). The effects of self-adaption for the optimal balance between superior performance (convergence) and the robustness (divergence) of the algorithm with regard to both simple and complex benchmark functions is investigated. This work …

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Simplified Sewerage Systems And Potential Application To Rural Louisiana Communities, Homero De Toledo Sobrinho May 2018

Simplified Sewerage Systems And Potential Application To Rural Louisiana Communities, Homero De Toledo Sobrinho

Senior Honors Theses

Today’s rapid growth in population on sub-urban areas has caused an increase in fecal coliforms to be discharged to down-streams and lakes. The unaffordability of conventional sewerage systems makes it inaccessible to big part of the population of rural communities to receive proper sanitation. Since population growth is only projected to increase during the next few years, action is necessary to change the course of the future of rural communities, more specifically described on this report, Louisiana’s communities. One option to offer affordable sewerage systems to the Louisiana region is that we utilize of the Simplified Sewerage technology. Simplified Sewerage …

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Nitrogen Doped Titanium Dioxide In The Photocatalytic Degradation Of Methylene Blue, Ashraya Upadhyaya May 2018

Nitrogen Doped Titanium Dioxide In The Photocatalytic Degradation Of Methylene Blue, Ashraya Upadhyaya

Senior Honors Theses

Titanium dioxide(TiO2) is a stable, effective and well-known photocatalyst for degradation of pollutants. However, its practical applications are limited due to the need for energy higher than 3.2 eV, or a wavelength lower than 390 nm (high frequency waves, ultraviolet and above) hindering its ability to effectively work in the visible light region (about 400 nm to 700 nm). Nitrogen-doped TiO2 (N-TiO2) has garnered some attention as a photocatalyst as it appears to work even in the visible light region. This could allow the utilization of a larger part of the solar spectrum. This thesis presents the results of photocatalytic …

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A Study Of 3d Printed Silver-Polymer Composite Structures, Cynthiya Shrestha May 2018

A Study Of 3d Printed Silver-Polymer Composite Structures, Cynthiya Shrestha

Senior Honors Theses

This research project primarily focuses on three major aspects: synthesis and inclusion of silver microparticles and nanowires within a polymer matrix, extrusion of composite filaments and, three-dimensional (3D) printing of multifunctional polymer composites. Since very few studies have explored the inclusion of silver nanoparticles in 3D printing materials, the findings from this study can be significant for additive manufacturing technology. Over the past few decades, the applications of additive manufacturing has been expanding considerably in several industries like automobile, biomechanics, aerospace, hardware engineering, to name a few. We are particularly interested in silver particles and nanowires because of their enhanced …

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Statistical Analysis And Comparison Of Optical Classification Of Atmospheric Aerosol Lidar Data, Kwasi Gyening Afrifa May 2018

Statistical Analysis And Comparison Of Optical Classification Of Atmospheric Aerosol Lidar Data, Kwasi Gyening Afrifa

Electrical & Computer Engineering Projects for D. Eng. Degree

This dissertation presents a new study for the analysis and classification of atmospheric aerosols in remote sensing LIDAR data. Information on particle size and associated properties are extracted from these remote sensing atmospheric data which are collected by a ground-based LIDAR system. This study first considers optical LIDAR parameter-based classification methods for clustering and classification of different types of harmful aerosol particles in the atmosphere. Since accurate methods for aerosol prediction behaviors are based upon observed data, computational approaches must overcome design limitations, and also consider appropriate calibration and estimation accuracy. Consequently, two statistical methods based on generalized linear models …

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Road Weather Impact Based Decision Support Applications: Developing A Department Of Transportation Winter Severity Index, Curtis Louis Walker May 2018

Road Weather Impact Based Decision Support Applications: Developing A Department Of Transportation Winter Severity Index, Curtis Louis Walker

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Adverse weather conditions are responsible for millions of vehicular crashes, thousands of vehicular deaths and billions of dollars in economic and congestion costs. Many transportation agencies utilize a performance or mobility metric to assess how well they are maintaining road access. This research focuses on the development of a winter severity index for the State of Nebraska (NEWINS). NEWINS is an event-driven index that was derived for the Nebraska Department of Transportation (NDOT) and its districts across the state. The NEWINS framework includes a categorical storm classification framework and climatological aspect to capture atmospheric conditions more accurately across diverse spatial …

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A Study On Residential Construction Energy Code Compliance In Nebraska, Aaron Thompson May 2018

A Study On Residential Construction Energy Code Compliance In Nebraska, Aaron Thompson

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Energy codes are easy to implement, but how effectively are they being followed? To determine energy code compliance of residential construction in Nebraska, a study was conducted in which seven key areas having the most effect on energy savings were analyzed. The study examined both urban and rural areas of the state and compared Nebraska to other states’ energy code compliance studies. The study found an eighty-eight percent average compliance in the key areas. Urban areas tended to be more compliant than rural areas. Nebraska is comparative in energy code compliance to other states. Yet, the state of Nebraska, code …

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Stochastic Finite Element Thermal Analysis Of A Ball Grid Array Package, Rahul Upreti May 2018

Stochastic Finite Element Thermal Analysis Of A Ball Grid Array Package, Rahul Upreti

Mechanical and Aerospace Engineering Theses - Archive

This study provides an insight into the factors which have a major impact on the probability of failure of a Ball Grid Array package. A stochastic finite element analysis was done on the package using First-order reliability method (FORM). The effects of uncertainty in material thermal conductivities, heat source, heat transfer coefficient and ambient temperature were studied. The average temperature at the die-junction interface was selected as failure criterion because the excess temperature at the junction is often a cause of failure. The performance of Finite Difference Method(FDM) and Semi-Analytic Complex Variable Method(SACVM) in computing sensitivities are compared. Results show …

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Air Flow Pattern And Path Flow Simulation Of Airborne Particulate Contaminants In A Cold-Aisle Containment High-Density Data Center Utilizing Airside Economization, Gautham Thirunavakkarasu May 2018

Air Flow Pattern And Path Flow Simulation Of Airborne Particulate Contaminants In A Cold-Aisle Containment High-Density Data Center Utilizing Airside Economization, Gautham Thirunavakkarasu

Mechanical and Aerospace Engineering Theses - Archive

The energy used by Information Technology Equipment (ITE) and the supporting data center equipment keeps rising as data center expansion continues worldwide. To contain the rising operation costs, data center administrators are resorting to cost cutting measures by not adhering to the ambient data center environment standards. In many cases, free cooling techniques are adopted to partially or completely relieve the usage of refrigeration units, which adds to huge cost savings but also allows for the increased risk of particulate and gaseous contaminations. The ASHRAE TC9.9 subcommittee, on Mission Critical Facilities, Data Centers, Technology Spaces, and Electronic Equipment, has provided …

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The Performance Of Quadrilateral Element With Rotational Degrees Of Freedom In Statics And Dynamics Analysis And Optimization, Xingzhi Wang May 2018

The Performance Of Quadrilateral Element With Rotational Degrees Of Freedom In Statics And Dynamics Analysis And Optimization, Xingzhi Wang

Mechanical and Aerospace Engineering Theses - Archive

Finite Element Method (FEM) is widely used in structural analysis, and the standard approach to increase the accuracy of analysis is increasing the total degrees of freedom (DOFs), namely, refine the mesh. By introducing the rotational DOFs, better accuracy can be achieved without change the mesh. The objective of this study was to investigate the performance of elements with rotational DOFs in statics and dynamics analysis and applying these elements to optimization. The implementation of three representative elements with rotational DOFs for statics analysis is reproduced. Also, this work implements these elements to dynamics analysis and optimization. The results show …

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Computational Study Of Form Factor Of 3rd Generation Open Compute Servers Using Different Dielectric Fluids For Single-Phase Immersion Cooling, Pranavi Rachamreddy May 2018

Computational Study Of Form Factor Of 3rd Generation Open Compute Servers Using Different Dielectric Fluids For Single-Phase Immersion Cooling, Pranavi Rachamreddy

Mechanical and Aerospace Engineering Theses - Archive

Computer system dependency has been increased in the modern world and that has encouraged the rapid growth of data centers in leading business units like banking, education, transportation, social media and many more. Data center is a facility that incorporates an organisation’s IT operations and equipment, as well as where it stores, processes, and manages the data. To fulfil the demands of data storage and data processing, corresponding increase in power density of servers are needed. The data center energy efficiency largely depends on the thermal management of servers. Currently, air cooling is the most widely used thermal management technique …

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New Broadband Common-Mode Filtering Structures Embedded In Differential Coplanar Waveguides For Dc To 40 Ghz Signal Transmission, Yujie He May 2018

New Broadband Common-Mode Filtering Structures Embedded In Differential Coplanar Waveguides For Dc To 40 Ghz Signal Transmission, Yujie He

Graduate Theses - Electrical and Computer Engineering

Coplanar waveguides (CPWs) provide effective transmission with low dispersion into the millimeter-wave frequencies. For high-speed signaling, differential transmission lines display an enhanced immunity to outside interference and are less likely to interfere with other signals, when compared to single-ended transmission lines. Common-mode (CM) conversion from the differential-mode (DM) signal energy can produce unintentional radiation as well as degraded board-level electromagnetic compatibility (EMC) and signal integrity SI environments. Due to the negative effects of CM signals, filtering structures are often used to suppress the propagation of these signals. The filtering structures introduced in this project all implement the same CM filter …

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Executive Summary_Feasibility Of Harbor-Wide Barrier Systems: Preliminary Analysis For Boston Harbor, Paul Kirshen May 2018

Executive Summary_Feasibility Of Harbor-Wide Barrier Systems: Preliminary Analysis For Boston Harbor, Paul Kirshen

Sustainable Solutions Lab

This report presents a preliminary feasibility assessment of harbor-wide barrier systems designed to protect Boston Harbor from coastal flooding caused by sea level rise (SLR) and storm surges. Conducted by the Sustainable Solutions Lab at the University of Massachusetts Boston and supported by the Boston Green Ribbon Commission, the study evaluates two primary configurations: an Outer Harbor Barrier (OHB) and an Inner Harbor Barrier (IHB). Using hydrodynamic modeling, economic cost-benefit analysis, and social vulnerability assessments, the study finds that while both barrier systems may reduce risk from extreme storm events, they do not mitigate regular tidal flooding without frequent gate …

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In-Vitro Simulation Of Acute Ischemic Stroke, Paolo Garcia May 2018

In-Vitro Simulation Of Acute Ischemic Stroke, Paolo Garcia

Biomedical Engineering Undergraduate Honors Theses

Acute ischemic stroke (AIS) is a condition that involves the occlusion of a blood vessel within the brain, effectively preventing the passage of oxygen and nutrients. AIS is highly prevalent in the United States, where nearly 795,000 strokes happen per year and 87% of those are ischemic. From a medical standpoint, the obstructing clot can be removed with the use of a stroke retrieval device. However, a need arises for testing the aforementioned devices on a patient’s specific vascular geometries in order to increase the likelihood of a successful procedure. Outlined is a process for developing a physical simulation of …

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Nanopore Biosensors For Molecular Detection And Analysis, Muhammad Usman Raza May 2018

Nanopore Biosensors For Molecular Detection And Analysis, Muhammad Usman Raza

Electrical Engineering Dissertations - Archive

Nanoscale fabrication techniques have led the march towards a new class of biosensors that were not possible to build in the past due to technological limitations. These molecular nanosensors can have biochemical, electromagnetic, acoustic, optical or electrophoretic detection modalities. One of these nanosensors, is solid state nanopores which use resistive pulse sensing in nanometer apertures in thin dielectric membranes. Solid state nanopores have been fabricated using cutting edge fabrication techniques to detect and analyze nanoscale biomolecules such as DNA, proteins, miRNA, viruses etc. These biosensors can be used as electronic sensors for biomarkers of certain diseases such as cancer and …

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A New Adaptive Multiscale Approach For The Dynamic Modeling And Simulation Of Biomolecular Systems, Ashley Chase Guy May 2018

A New Adaptive Multiscale Approach For The Dynamic Modeling And Simulation Of Biomolecular Systems, Ashley Chase Guy

Mechanical and Aerospace Engineering Dissertations - Archive

This dissertation presents three developments in the simulation of sub-micron dynamical systems. First, a new thermostat formulation is shown to strictly enforce the constant temperature constraint necessary in many thermodynamic ensembles. This formulation also allows the system to quickly evolve to a low-potential state. Next, this new thermostat formulation is leveraged to extend a continuum-regime multiscale formulation to the atomistic regime allowing for equivalent time histories to be generated in significantly less computation time. Finally, an adaptive multiscale formulation allows for potential forces with time varying magnitudes to contribute to the overall dynamics similarly resulting in equivalent time histories in …

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Development Of An In Vitro Platform For The Exploration Of Skeletal Muscle Cell Mechanobiology, Sydney Spradlin May 2018

Development Of An In Vitro Platform For The Exploration Of Skeletal Muscle Cell Mechanobiology, Sydney Spradlin

Biomedical Engineering Undergraduate Honors Theses

Muscles have the natural ability to regenerate when damaged. This works to keep the body functioning, unless this ability is overwhelmed. Volumetric muscle loss (VML) occurs when a substantial amount of a muscles mass is lost. This leads to the development of scar tissue, and often a loss of function. In order to find a solution for this condition, in vitro models are needed to explore the mechanobiology of skeletal muscle cells. Two platforms were developed in this study, to explore 3 factors: orientation, strain, and supporting structure. One platform used fibronectin stamped lanes on PDMS to encourage cell growth …

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Pressure Acquisition System For In Vitro Mitral Valve Analysis, Laura Peck May 2018

Pressure Acquisition System For In Vitro Mitral Valve Analysis, Laura Peck

Biomedical Engineering Undergraduate Honors Theses

In vitro testing of the mitral valve chordae tendineae is utilized to aid in the understanding of the stresses that occur in vivo and improve upon surgical solutions that exist for mitral valve repair. This project aimed to design the water control system for a left heart simulation chamber, as well as the pressure acquisition inside the chamber. A solenoid valve was utilized to control the water supply to the tank and was powered utilizing National Instruments software. National Instruments hardware and software was also used with the pressure transducer in order to obtain pressure readings from the chamber. The …

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