Engineering Commons^™

Development Of A Model To Simulate The Single-Limb Stance Phase Of Walking To Determine The Limits Of Stability, Clifford Lee Hancock

Bioengineering Theses - Archive

Falls during walking are the primary cause of injuries for older persons and present a high associated cost to society due to the resulting treatment. Hence, the control of balance while moving is an essential issue especially amongst the elderly population. Better understanding of why and how these falls occur could lead to better fall prevention methods, therapies, or devices. These changes could effectively decrease overall emergency room visits, create more room in hospitals for other demands, and decrease medical costs for fall-related disabilities and deaths amongst patients overall. This study attempted to develop an inverted pendulum model of the …

Microfluidic Device For Determining Preferential Cell Migration Toward Extracellular Matrix Proteins, Neil Hall

Bioengineering Theses - Archive

Extracellular matrix (ECM) proteins interact with cells in bodily microenvironments by influencing their essential cellular processes in growth, survival, migration and repair after injury. In this study, a novel microfluidic device was developed to study preferential interactions of cells with multiple extracellular matrix proteins simultaneously in an unbiased manner. The implementation of PDITC-treated glass and a controlled laminar flow of multiple separated, soluble proteins was used to create an unbiased microenvironment in which ECM proteins are adsorbed on the glass surface in a manner that simultaneously exposes cells to multiple proteins, and allows them to migrate or outgrow toward the …

Recombinant Expression, Purification And Kinetic Characterization Of F₄₂₀-Cofactor Dependent Glucose-6-Phosphate Dehydrogenase From Mycobacterium Tuberculosis, Tijani Osumah

Bioengineering Theses - Archive

The FGD (F₄₂₀-dependent Glucose-6-phosphate dehydrogenase) enzyme is an F₄₂₀ Cofactor (7,8-didemethyl-8-hydroxy-5-deazariboflavin) dependent enzyme found in Mycobacterium tuberculosis, the causative agent of tuberculosis (TB). TB is still a prominent cause of illness and death worldwide. Because FGD is not found in humans, makes it a good target for drug development. By understanding the hydride transfer mechanism of the FGD in detail, we can aid in the improvement of drug targeting and development for the treatment of TB. FGD catalyzes the conversion of glucose-6-phosphate to 6-phosophogluconolactone. This project focuses on the purification and kinetic characterization of recombinant FGD using steady-state and pre-steady …

Improving Cooling Efficiency Of Servers By Replacing Smaller Chassis Enclosed Fans With Larger Rack-Mount Fans, Bharath Nagendran

Mechanical and Aerospace Engineering Theses - Archive

As a common practice in the data center industry, chassis fans are used to direct air flow independent from neighboring servers. However, these fans are less efficient compared to larger rack level counterparts and also operate at higher sound levels. In this study, a novel approach is proposed whereby the smaller chassis enclosed fans are replaced with an array of larger fans, installed behind the stacked servers that share air flow. As a baseline study for comparison of the current scenario, a CPU dominated 1.5U Open Compute server, with four 60mm fans installed within the server, is characterized experimentally for …

Comparative Analysis Of Widely Used Air Containment Systems In Commercial Data Centers For Maximum Cooling Performance, Kasturi Rangan Rajagopalan

Mechanical and Aerospace Engineering Theses - Archive

Many data centers implement containment systems to improve cooling system performance. Literature review shows that Hot Aisle Containment System (HACS) have higher supply air temperature set point than Cold Aisle Containment Systems (CACS) [1]. CACS in data centers have claims to support higher density loads when compared to HACS systems [2]. Data center owners suggest that containment of a group of racks can be a very effective technique to improve cooling performance. On the other hand, others suggest that fewer area for containment is better than no containment in data centers that favours the partially contained architectures of HACS and …

Real Time Temperature Prediction In A Data Center Environment Using An Adaptive Algorithm, Vishok Amar Kumar

Mechanical and Aerospace Engineering Theses - Archive

Most organizations around the world rely on information systems to run their operations. Data centers are hence a crucial aspect of most organizational operations to ensure business continuity. Disruption in the working of a system can impair the business largely and hence optimizing the environment in which the servers and storage devises of a data center are housed becomes extremely challenging. Most industries design the data center infrastructure to handle peak load conditions thus ensuring a continual functionality of its hosted environment. However, the cost of maintaining such a system is very high. This gives rise to the need of …

A Computational Model To Characterize Different Flow Regimes For Microscale Re-Entry Satellites, Sudharsan Thiruvenkadam

Mechanical and Aerospace Engineering Theses - Archive

Atmospheric re-entry vehicles experience different flow regimes during flight due to the change in atmospheric density along the re-entry trajectory. This change in density creates non-equilibrium regions on the order of mean free path, called Knudsen layer. In the design of atmospheric re-entry vehicles, the flux variations near the wall of the re-entry vehicles are of critical importance. Traditional CFD simulations that use Navier-Stokes equations fail to predict the flow in the Knudsen layer. The Direct Simulation Monte Carlo (DSMC) method is accurate for all flow regimes, and correctly models the Knudsen layer but is computationally expensive. The computational cost …

The Integration Of Sustainable Development Competencies In Irish Engineering Education: Findings Of A Curriculum Content Investigation Of Four Engineering Programmes, Iacovos Nicolaou, Eddie Conlon

Conference papers

This paper presents the initial findings of an investigation of the Sustainable Development (SD) content in five professional engineering degree programmes in a large Irish Institute of Technology.

A comprehensive investigation of the modules content was conducted to see to what extent the learning outcomes for SD as set out in the Barcelona Declaration and SD competencies were covered by the modules. It was found that 40% of the 137 modules included SD learning outcomes and/or addressed SD competencies. The modules have a focus on environmental issues and tend to address only one of the three dimensions, environmental, social and …

Control Of The Shunt Active Power Filter Under Non-Ideal Grid Voltage And Unbalanced Load Conditions, Samet Biricik, Soydan Redif, Ozgur Ozerdem, Malabika Basu

Conference papers

In this study a new method is proposed in order to improve the harmonic suppression efficiency of Active Power Filter for the problems caused by the distorted and unbalanced voltages with unbalanced load currents in control strategy. The proposed control method gives an adequate compensating current reference even for non ideal voltage and unbalanced current conditions. The results of simulation study are presented to verify the effectiveness of the proposed control technique in this study.

Sustainability Of Grid-Tie Micro-Generation System, Lubna Mariam, Malabika Basu, Michael Conlon

Conference papers

Both the outcomes of technical and economical feasibility analysis of a renewable based power system should be positive to achieve sustainability. Energy production or Renewable Energy Feed-in-Tariff (REFIT) cost should be lower or higher respectively than the existing grid electricity cost. As the renewable energy sources are variable and where REFIT is also applicable for the system connected to the grid, the detailed hourly time series analysis is very important. Based on this issue, in this paper, a techno-economic feasibility analysis has been performed for a PV based micro-generation system to find out the possible ways to make the micro-generation …

Fabrication And Characterization Of Single Electron Device And Study Of Energy Filtering In Single Electron Transport, Liang-Chieh Ma

Material Science and Engineering Dissertations - Archive

Single electron devices, in which transport of single electrons is precisely controlled, hold a great promise as important components of future electronic devices and sensors. However, technical challenges have prevented their implementations to practical electronic and sensing systems. First of all, the fabrication of single electron devices requires their components to be defined and arranged in nanoscale precision, a great challenge for a large-scale fabrication. Secondly, for room temperature operation, the single-electron charging energy should be much larger than the room-temperature thermal energy, ~25 meV, requiring use of extremely small Coulomb island, which is difficult to control. This has limited …

Corrosion And Hydrogen Embrittlement Of Nanocrystalline Nickel, Tapas Desai

Material Science and Engineering Theses - Archive

Nanocrystalline (nc) materials have attracted the interest of the scientific community because of their unique physical and mechanical properties. However, limited research has been performed to analyze their electrochemical behavior. The majority of research in the field of electrochemical and corrosion behavior exists for electrodeposited nanocrystalline metals.This research studies the behavior of sputter-deposited nc Nickel films in corrosive and hydrogen environment by potentiodynamic polarization and microindentation. The surface morphology and composition of the samples was examined by Scanning Electron Microscopy and Energy Dispersive X-Ray spectroscopy. Bulk Ni samples exhibit mild passivation in 3.5 % NaCl solution. The surface reveals a …

Improving Productivity Of Tunnel Boring Machines, Nicholas Jencopale

Civil Engineering Theses - Archive

Tunneling with tunnel boring machines (TBMs) is one of the most mechanized and sophisticated processes within the construction industry. However, there are risks when venturing down several hundred feet where the conditions cannot be accurately determined in advance. Months and years of planning, engineering, profiling, researching, and scheduling go into a typical tunneling project before any ground breaking event. This thesis will discuss in detail the growing technologies of the tunneling process using tunnel boring machines (TBM). First, some background information on tunneling and the use of a TBM will be provided to introduce the process and the industry being …

Corrosion Potentials Of Lightweight Concrete Wrapped With Fiber Reinforced Polymers (Frp), Eric Goucher

Civil Engineering Theses - Archive

The purpose of this research was to investigate the effects of Fiber Reinforced Polymer wraps on corrosion protection of lightweight concrete. Many studies have been undertaken for normal density concrete, but there are very few studies regarding lightweight concrete and externally bonded FRP wraps. This experiment involved the use of an accelerated corrosion test to determine the corrosion protection that FRP would afford lightweight concrete, while making a comparison with a similarly proportioned normalweight mix. 42 cylinders were subject to a constant 12 V power from a DC Power Supply while being immersed in a 5% NaCl for a period …

Structural And Material Performance Of Rubberized And Hybrid Concrete Pipes, Mohammad Mohammadagha

Civil Engineering Theses - Archive

This study investigates how the combination of steel fiber, crumb rubber, synthetic fiber, and conventional steel cage will improve the ductility of regular concrete pipes and thin-walled semi-rigid concrete pipes. In this study, pipes with four different concrete mixtures were produced and tested: (1) Steel Bar Reinforced Concrete Pipe (SBRCP), (2) Crumb Rubber Reinforced Concrete Pipe (CRRCP), (3) Steel Fiber Reinforced Concrete Pipe (SFRCP), and (4) Synthetic Fiber Reinforced Concrete Pipe (SNFRCP). This study investigates how the variation of the fiber volume fraction and crumb rubber content in concrete mix affects the behavior of pipes with diameters ranging from 24in. …

Ensemble Streamflow Forecasting For The Upper Trinity River Basin In Texas, Manabendra Saharia

Civil Engineering Theses - Archive

By allowing for routine use of longer-lead quantitative precipitation forecast (QPF) in hydrologic prediction, ensemble forecasting offers hope for extending the lead time for short-range streamflow forecasting. In this work, this potential is assessed by comparatively evaluating ensemble streamflow hindcasts forced by Day 1-3 QPF with those forced by Day 1 QPF for five headwater basins in the Upper Trinity River Basin in North Texas. The hindcasts are generated for a 7-year period of 2004 to 2010 using the Hydrologic Ensemble Forecast Service (HEFS), which operates on the Community Hydrologic Prediction System (CHPS) of the National Weather Service (NWS). HEFS …

The Relation Between Freeway Average Speed And Speed Noise, Bahar Zarin

Civil Engineering Theses - Archive

A significant amount of energy could be saved by applying traffic management policies. Many factors affect the fuel consumption rate, and the most important traffic-related ones include variables such as speed, number of stops, the speed noise, and the acceleration noise. Fuel consumption models for both urban and highway traffic are used to evaluate the effect of these factors. Previous literature shows the speed and the acceleration of the individual vehicles as well as the aero-dynamic effects are the most considered parameters in highway fuel consumption models. However, the existing models are based on the average or cruising speed and …

Estimation Of Wave Energy From Wind Velocity, Jonathan Blackledge, Eugene Coyle, Derek Kearney, Ronan Mcguirk, Brian Norton

Articles

The aim of this paper is to report on a possible correlation between the Levy index for wind velocity and the mean Energy Density of sea surface waves in the same location. The result is based on data obtained from 6 buoys located around the coast of Ireland and maintained by the Marine Institute of Ireland and a further 144 buoys located at various locations off the coast of the United States of America and maintained by the National Data Buoy Centre. These buoys provide historical data on the wind velocity, wave height and wave period as well as other …

Gis-Based Expert Systems Model For Predicting Habitat Suitability Of Blackside Dace, Benjamin L. Blandford, John Ripy, Ted H. Grossardt, Ryan Evans, Sara Hines

Kentucky Transportation Center Presentations

This study presents a GIS-based predictive habitat suitability model for the blackside dace, a federally-listed threatened species of the Upper Cumberland River basin in southeastern Kentucky. The model is a rules-based system which incorporates expert knowledge about habitat preferences for the species. The five habitat factors identified by experts and included in this model are stream gradient, canopy coverage, riparian vegetation type, riparian zone width, and stream order. Using GIS, the five habitat parameters were parameterized and combined across the entire stream network. Combinations were evaluated by blackside dace experts in terms of habitat suitability. The resulting model was tested …

X-Ray Scattering Investigations Of Metallic Thin Films, Andrew Warren

Electronic Theses and Dissertations

Nanometric thin films are used widely throughout various industries and for various applications. Metallic thin films, specifically, are relied upon extensively in the microelectronics industry, among others. For example, alloy thin films are being investigated for CMOS applications, tungsten films find uses as contacts and diffusion barriers, and copper is used often as interconnect material. Appropriate metrology methods must therefore be used to characterize the physical properties of these films. Xray scattering experiments are well suited for the investigation of nano-scaled systems, and are the focus of this doctoral dissertation. Emphasis is placed on (1) phase identification of polycrystalline thin …

Robust Subspace Estimation Using Low-Rank Optimization. Theory And Applications In Scene Reconstruction, Video Denoising, And Activity Recognition., Omar Oreifej

Electronic Theses and Dissertations

In this dissertation, we discuss the problem of robust linear subspace estimation using low-rank optimization and propose three formulations of it. We demonstrate how these formulations can be used to solve fundamental computer vision problems, and provide superior performance in terms of accuracy and running time. Consider a set of observations extracted from images (such as pixel gray values, local features, trajectories . . . etc). If the assumption that these observations are drawn from a liner subspace (or can be linearly approximated) is valid, then the goal is to represent each observation as a linear combination of a compact …

Similarity Of Climate Control On Base Flow And Perennial Stream Density In The Budyko Framework, Liuliu Wu

Electronic Theses and Dissertations

Streams are classified into perennial, intermittent, and ephemeral streams based on flow durations. Perennial stream is the basic network, while intermittent or ephemeral stream is the expanded network. Connection between perennial stream and base flow at the mean annual scale exists since one of the hydrologic functions of perennial stream is to deliver runoff even in low flow seasons. The partitioning of precipitation into runoff and evaporation at the mean annual scale, on the first order, is captured by the ratio of potential evaporation to precipitation (Ep/P called climate aridity index) based on the Budyko hypothesis. The primary focus of …

Development And Characterization Of Nanoparticlee Enhancements In Pyrolysis-Derived High Temperature Composites, James Mckee

Electronic Theses and Dissertations

Thermal protection systems, which are commonly used to protect spacecraft during atmospheric entry, have traditionally been made of materials which are traditionally high in manufacturing costs for both the materials needed and the manufacturing complexity, such as carbon-carbon composites and aerogels. [1] In addition to their manufacturing costs, these materials are also limited in their strength, such as PICA, in a way that necessitate the use of tiles as opposed to single structures because they are not capable of supporting larger structures. [2] The limitations of polymer reinforced composites have limited their entry into these applications, except for pyrolyzed composite …

Silicon Photonic Devices For Optical Delay Lines And Mid Infrared Applications, Saeed Khan

Electronic Theses and Dissertations

Silicon photonics has been a rapidly growing subfield of integrated optics and optoelectronic in the last decade and is currently considered a mature technology. The main thrust behind the growth is its compatibility with the mature and low-cost microelectronic integrated circuits fabrication process. In recent years, several active and passive photonic devices and circuits have been demonstrated on silicon. Optical delay lines are among important silicon photonic devices, which are essential for a variety of photonic system applications including optical beam-forming for controlling phased-array antennas, optical communication and networking systems and optical coherence tomography. In this thesis, several types of …

Limitations Of Micro And Macro Solutions To The Simulation Interoperability Challenge: An Ease Case Study, John Barry

Electronic Theses and Dissertations

This thesis explored the history of military simulations and linked it to the current challenges of interoperability. The research illustrated the challenge of interoperability in integrating different networks, databases, standards, and interfaces and how it results in U.S. Army organizations constantly spending time and money to create and implement irreproducible Live, Virtual, and Constructive (LVC) integrating architectures to accomplish comparable tasks. Although the U.S. Army has made advancements in interoperability, it has struggled with this challenge since the early 1990s. These improvements have been inadequate due to evolving and growing needs of the user coupled with the technical complexities of …

Measuring The Evolving Internet Ecosystem With Exchange Points, Mohammad Zubair Ahmad

Electronic Theses and Dissertations

The Internet ecosystem comprising of thousands of Autonomous Systems (ASes) now include Internet eXchange Points (IXPs) as another critical component in the infrastructure. Peering plays a significant part in driving the economic growth of ASes and is contributing to a variety of structural changes in the Internet. IXPs are a primary component of this peering ecosystem and are playing an increasing role not only in the topology evolution of the Internet but also inter-domain path routing. In this dissertation we study and analyze the overall affects of peering and IXP infrastructure on the Internet. We observe IXP peering is enabling …

Influence Of Task-Role Mental Models On Human Interpretation Of Robot Motion Behavior, Scott Ososky

Electronic Theses and Dissertations

The transition in robotics from tools to teammates has begun. However, the benefit autonomous robots provide will be diminished if human teammates misinterpret robot behaviors. Applying mental model theory as the organizing framework for human understanding of robots, the current empirical study examined the influence of task-role mental models of robots on the interpretation of robot motion behaviors, and the resulting impact on subjective ratings of robots. Observers (N = 120) were exposed to robot behaviors that were either congruent or incongruent with their task-role mental model, by experimental manipulation of preparatory robot task-role information to influence mental models (i.e., …

A Real Option Dynamic Decision (Rodd) Framework For Operational Innovations, Wilawan Onkham

Electronic Theses and Dissertations

Changing the business operations and adopting new operational innovations, have become key features for a business solution approach. However, there are challenges for developing innovative operations due to a lack of the proper decision analysis tools, lack of understanding the impacts transition will have on operational models, and the time limits of the innovation life cycle. The cases of business failure in operational innovation (i.e. Eastman Kodak Company and Borders Group Inc.,) support the need for an investment decision framework. This research aims to develop a Real Option Dynamic Decision (RODD) framework for decision making, to support decision makers for …

Systems Geometry: A Methodology For Analyzing Emergent System Of Systems Behaviors, Christina Bouwens

Electronic Theses and Dissertations

Recent advancements in technology have led to the increased use of integrated ‘systems of systems’ (SoS) which link together independently developed and usable capabilities into an integrated system that exhibits new, emergent capabilities. However, the resulting SoS is often not well understood, where secondary and tertiary effects of tying systems together are often unpredictable and present severe consequences. The complexities of the composed system stem not only from system integration, but from a broad range of areas such as the competing objectives of different constituent system stakeholders, mismatched requirements from multiple process models, and architectures and interface approaches that are …

Suction Detection And Feedback Control For The Rotary Left Ventricular Assist Device, Yu Wang

Electronic Theses and Dissertations

The Left Ventricular Assist Device (LVAD) is a rotary mechanical pump that is implanted in patients with congestive heart failure to help the left ventricle in pumping blood in the circulatory system. The rotary type pumps are controlled by varying the pump motor current to adjust the amount of blood flowing through the LVAD. One important challenge in using such a device is the desire to provide the patient with as close to a normal lifestyle as possible until a donor heart becomes available. The development of an appropriate feedback controller that is capable of automatically adjusting the pump current …