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2008

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Articles 151 - 180 of 5193

Full-Text Articles in Engineering

New Consolidation Of Emission And Processing For Air Quality Modeling Assessment In Asia, Yuan Du Dec 2008

New Consolidation Of Emission And Processing For Air Quality Modeling Assessment In Asia, Yuan Du

Masters Theses

Gridded Asian emission input with fine resolutions for regional photochemical air quality modeling is absent from current studies. A new top-down emission process based on GIS-FORTRAN program has been developed in this study to consolidate the current available regional emissions in Asia and provide model-ready emission input with more flexibility. The INTEX-B anthropogenic emission inventory in 2006 integrated with biogenic from GEIA, as well as biomass burning and ship emissions from TRACE-P has been adopted as the top-level emissions, which are then spatially allocated into grid-cell level by our GIS application. The spatial allocation factors generated for this process are …


The Application Of A Two-Dimensional Sediment Transport Model In A Cumberland Plateau Mountainous Stream Reach With Complex Morphology And Coarse Substrate, Daniel Hale Johnson Dec 2008

The Application Of A Two-Dimensional Sediment Transport Model In A Cumberland Plateau Mountainous Stream Reach With Complex Morphology And Coarse Substrate, Daniel Hale Johnson

Masters Theses

Among river engineers there is growing recognition that the success of a stream restoration project is dependent on the accurate prediction of sediment transport along a reach. To aid the design process, several numerical one- and multi-dimensional models have been developed to quantify in-stream sediment transport and hydraulic characteristics, and multiple sampling techniques have been proposed to establish the upstream sediment supply. However, the governing physical boundaries and variables (i.e., Manning’s ‘n’ variable, energy slope, and upstream sediment supply) required to initiate a sediment transport simulation are time consuming and difficult to measure in the field, and the estimation of …


Analysis Of Cavity Flow And The Effects Of A Rod In Crossflow, Richard David Loewen Dec 2008

Analysis Of Cavity Flow And The Effects Of A Rod In Crossflow, Richard David Loewen

Masters Theses

Subsonic cavity flow tests of an L/D = 3.5 cavity, with three different diameter rods in crossflow, 1/8", 3/16", and 1/4", were conducted using the High Speed Wind Tunnel in the University of Tennessee Space Institute’s Gas Dynamic Laboratory. The average Mach number flow over the duration of the four phase testing sequence was 0.52, with a unit Reynolds number of 13.8 x 106. With the use of a dynamic pressure transducer and a laser PIV system, Spectral and Flow Visualization data was collected with aim of investigating the effect of the rods in crossflow on cavity flow. However, for …


Removing Acetic Acid From The Urex+ Process, Jessica Anne Mitchell Dec 2008

Removing Acetic Acid From The Urex+ Process, Jessica Anne Mitchell

Masters Theses

Acetic acid needs to be removed from a waste stream in the UREX+ process so that nitric acid can be recycled and possible interference with downstream steps can be avoided. Acetic acid arises from acetohydroxamic acid (AHA) used to suppress plutonium in the first step of the UREX+ process. Later, it is hydrolyzed into hydroxyl amine nitrate and acetic acid. Many common separation technologies were examined, and solvent extraction was determined to be the best choice under process conditions. Solvents already used in the UREX+ process were then tested to determine if they would be sufficient for the removal of …


Laser Processing Of Refractory Metal - Refractory Carbide Alloys, Deepak Rajput Dec 2008

Laser Processing Of Refractory Metal - Refractory Carbide Alloys, Deepak Rajput

Masters Theses

The objective of the present study was to laser process a refractory metal – refractory carbide alloy based on W-Ti-C ternary system for severe service applications. The key concept was to cast a eutectic alloy of tungsten and titanium carbide/carbonitride straight from the melt through laser materials processing route. In the present study, a WTi- C ternary alloy has been laser processed into three-dimensional objects and surface protective coatings. Two novel fabrication systems were designed to build threedimensional objects, namely tower nozzle solid freeform fabrication system and axissymmetric laser powder deposition system. W-Ti-C alloy based protective coatings were deposited on …


Preliminary Design, Flight Simulation, And Task Evaluation Of A Mars Airplane, Dodi Deanne Walker Dec 2008

Preliminary Design, Flight Simulation, And Task Evaluation Of A Mars Airplane, Dodi Deanne Walker

Masters Theses

A limited aerodynamic, stability and control, and task evaluation of a new rocket-powered Mars airplane design was conducted. The Mars airplane design, designated the Argo VII, was patterned after the NASA ARES-2 design. The aerodynamic and stability and control parameters of the Argo VII were determined using analytical and computational techniques and were comparable to those of the ARES-2. The Argo VII was predicted to be statically stable and damped in all axes on Earth and Mars. A series of flight tests were performed using a MATLAB Simulink-based flight simulation program to assess the performance, longitudinal flying qualities, and mission …


An Empirical Study Of Performance Benefits Of Network Coding In Multihop Wireless Networks, Y. Charlie Hu, Chih-Chun Wang Dec 2008

An Empirical Study Of Performance Benefits Of Network Coding In Multihop Wireless Networks, Y. Charlie Hu, Chih-Chun Wang

Department of Electrical and Computer Engineering Technical Reports

Recently, network coding has gained much popularity and several practical routing schemes have been proposed for wireless mesh networks that exploit interflow network coding for improved throughput. However, the evaluation of these protocols either assumed simple topologies and traffic patterns such as opposite flows along a single chain, or small, dense networks which have ample overhearing of each other’s transmissions in addition to many overlapping flows. In this paper, we seek to answer the fundamental question: how much performance benefit from network coding can be expected for general traffic patterns in a moderate-sized wireless mesh network? We approach this question …


On Step Sizes, Stochastic Shortest Paths, And Survival Probabilities In Reinforcement Learning, Abhijit Gosavi Dec 2008

On Step Sizes, Stochastic Shortest Paths, And Survival Probabilities In Reinforcement Learning, Abhijit Gosavi

Engineering Management and Systems Engineering Faculty Research & Creative Works

Reinforcement learning (RL) is a simulation-based technique useful in solving Markov decision processes if their transition probabilities are not easily obtainable or if the problems have a very large number of states. We present an empirical study of (i) the effect of step-sizes (learning rules) in the convergence of RL algorithms, (ii) stochastic shortest paths in solving average reward problems via RL, and (iii) the notion of survival probabilities (downside risk) in RL. We also study the impact of step sizes when function approximation is combined with RL. Our experiments yield some interesting insights that will be useful in practice …


Pmu Placement For Power System Observability Using Binary Particle Swarm Optimization, S. Chakrabarti, Ganesh K. Venayagamoorthy, E. Kyriakides Dec 2008

Pmu Placement For Power System Observability Using Binary Particle Swarm Optimization, S. Chakrabarti, Ganesh K. Venayagamoorthy, E. Kyriakides

Electrical and Computer Engineering Faculty Research & Creative Works

A binary particle swarm optimization (BPSO) based methodology for the optimal placement of phasor measurement units (PMUs) for complete observability of a power system is presented in this paper. The objectives of the optimization problem are to minimize the total number of PMUs required, and to maximize the measurement redundancy at the power system buses. Simulation results on the IEEE 14-bus and 30-bus test systems are presented in this paper.


Improvements In Steel Melting Efficiency -- Industrial Trials, Kent D. Peaslee, Semen Naumovich Lekakh, Edith Martinez Dec 2008

Improvements In Steel Melting Efficiency -- Industrial Trials, Kent D. Peaslee, Semen Naumovich Lekakh, Edith Martinez

Materials Science and Engineering Faculty Research & Creative Works

Industrial trials were completed to improve energy efficiency in steel melting. First, the benefits of increased chemical energy from an oxyfuel burner and a Co-Jet system in a basic 20 ton electric arc furnace (EAF) were studied. Observations and measurements were made during production before and after the installation of the two systems. The additional chemical energy improved energy efficiency and resulted in increased production. In addition, production using a basic EAF practice was compared to the traditional acid EAF practice. Second, an industrial trial using a 750 lb ladle with a combination of a lightweight alumina castable refractory and …


Energy Efficiency In Steel Casting Production, Raymond Monroe, Kent D. Peaslee, R. Eppich Dec 2008

Energy Efficiency In Steel Casting Production, Raymond Monroe, Kent D. Peaslee, R. Eppich

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.


Multiple Radar Data Merging In Hydro-Nexrad, Witold F. Krajewski, Bong Chul Seo, Anton Kruger, Piotr Domaszczynski, Gabriele Villarini, James A. Smith Dec 2008

Multiple Radar Data Merging In Hydro-Nexrad, Witold F. Krajewski, Bong Chul Seo, Anton Kruger, Piotr Domaszczynski, Gabriele Villarini, James A. Smith

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Hydro-NEXRAD merging algorithms include two options: (1) data-based merging; and (2) product-based merging. Data-based merging algorithm takes volume scan reflectivity data from all radars involved through preprocessing algorithm that performs volume data quality control, interpolates data to synchronize temporal scale between individual radars, and finally combines data onto a common geographic grid. Reflectivity values for a given location are assigned by a weighting function with respect to the distance from the radar. This single reflectivity field is then converted to rainfall amounts using a user-requested standard approach. In product-based merging algorithm reflectivity data from multiple radars are all converted …


Creating Tomorrow, Fall 2008, College Of Engineering Dec 2008

Creating Tomorrow, Fall 2008, College Of Engineering

College of Engineering Magazines

Annual magazine for the College of Engineering at Utah State University.


A Model Based Fault Detection And Prognostic Scheme For Uncertain Nonlinear Discrete-Time Systems, Balaje T. Thumati, Jagannathan Sarangapani Dec 2008

A Model Based Fault Detection And Prognostic Scheme For Uncertain Nonlinear Discrete-Time Systems, Balaje T. Thumati, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A new fault detection and prognostics (FDP) framework is introduced for uncertain nonlinear discrete time system by using a discrete-time nonlinear estimator which consists of an online approximator. A fault is detected by monitoring the deviation of the system output with that of the estimator output. Prior to the occurrence of the fault, this online approximator learns the system uncertainty. In the event of a fault, the online approximator learns both the system uncertainty and the fault dynamics. A stable parameter update law in discrete-time is developed to tune the parameters of the online approximator. This update law is also …


Measurement Of Liquid Water Accumulation In A Proton Exchange Membrane Fuel Cell With Dead-Ended Anode, Jason B. Siegel, Denise A. Mckay, Anna G. Stefanopoulou Dec 2008

Measurement Of Liquid Water Accumulation In A Proton Exchange Membrane Fuel Cell With Dead-Ended Anode, Jason B. Siegel, Denise A. Mckay, Anna G. Stefanopoulou

Engineering: Faculty Publications

The operation and accumulation of liquid water within the cell structure of a polymer electrolyte membrane fuel cell (PEMFC) with a dead-ended anode is observed using neutron imaging. The measurements are performed on a single cell with 53 square centimeter active area, Nafion 111-IP membrane and carbon cloth Gas Diffusion Layer (GDL). Even though dry hydrogen is supplied to the anode via pressure regulation, accumulation of liquid water in the anode gas distribution channels was observed for all current densities up to 566 mA cm-2 and 100% cathode humidification. The accumulation of liquid water in the anode channels is followed …


Synergistic Effect Of Retinoic Acid, Nerve Growth Factor And Laminin For Enhanced Neurite Extension, Shrarath Ashwin Sriman Dec 2008

Synergistic Effect Of Retinoic Acid, Nerve Growth Factor And Laminin For Enhanced Neurite Extension, Shrarath Ashwin Sriman

Masters Theses

Peripheral Nerve Injury is one of the most common and serious traumatic injuries. About 300,000 cases of peripheral nerve injury are reported annually in Europe and another 50,000 procedures performed annually in the United States. Peripheral nerve injury can lead to lifelong disability and also death in severe cases. Repair techniques remain a major challenge because of lack of efficient regeneration. Though techniques like autografts are highly efficient, they face a lot of drawbacks. Alternate methods focus on the use of growth supporting and enhancement components in nerve guidance channels. Current research necessitates the use of a combination of compounds …


A Fundamental Study Of The Pcr Amplification Of Gc-Rich Dna Templates, T. G. Mamedov, Elsje Pienaar, Scott E. Whitney, Joel R. Termaat, G. Carvill, R. Goliath, Anuradha Subramanian, Hendrik J. Viljoen Dec 2008

A Fundamental Study Of The Pcr Amplification Of Gc-Rich Dna Templates, T. G. Mamedov, Elsje Pienaar, Scott E. Whitney, Joel R. Termaat, G. Carvill, R. Goliath, Anuradha Subramanian, Hendrik J. Viljoen

Hendrik J. Viljoen Publications

A theoretical analysis is presented with experimental confirmation to conclusively demonstrate the critical role that annealing plays in efficient PCR amplification of GC-rich templates. The analysis is focused on the annealing of primers at alternative binding sites (competitive annealing) and the main result is a quantitative expression of the efficiency (η) of annealing as a function of temperature (TA), annealing period (tA), and template composition. The optimal efficiency lies in a narrow region of TA and tA for GC-rich templates and a much broader region for normal GC templates. To confirm the …


Neural Network Output Feedback Control Of A Quadrotor Uav, Jagannathan Sarangapani, Travis Alan Dierks Dec 2008

Neural Network Output Feedback Control Of A Quadrotor Uav, Jagannathan Sarangapani, Travis Alan Dierks

Electrical and Computer Engineering Faculty Research & Creative Works

A neural network (NN) based output feedback controller for a quadrotor unmanned aerial vehicle (UAV) is proposed. The NNs are utilized in the observer and for generating virtual and actual control inputs, respectively, where the NNs learn the nonlinear dynamics of the UAV online including uncertain nonlinear terms like aerodynamic friction and blade flapping. It is shown using Lyapunov theory that the position, orientation, and velocity tracking errors, the virtual control and observer estimation errors, and the NN weight estimation errors for each NN are all semi-globally uniformly ultimately bounded (SGUUB) in the presence of bounded disturbances and NN functional …


'Fabrication And Characterization Of Polymer Blends And Composites Derived From Biopolymers', Suraj Sharma Dec 2008

'Fabrication And Characterization Of Polymer Blends And Composites Derived From Biopolymers', Suraj Sharma

All Dissertations

This research focuses on fabricating blends and composites from natural polymers especially from proteins and natural epoxy, and describing the properties of plastics made from them. Specifically, plastic samples from partially denatured feathermeal and bloodmeal proteins, derived from the animal co-products (rendering) industry, were successfully produced through a compression molding process. The modulus (stiffness) of the material obtained was found to be comparable with that of commercial synthetic materials, such as polystyrene, but was found to have lower toughness characteristics, which is a common phenomenon among plastics produced from animal and plant proteins. Therefore, this study explored blending methods for …


Real-Time Automatic Linear Feature Detection In Images, Guang Zeng Dec 2008

Real-Time Automatic Linear Feature Detection In Images, Guang Zeng

All Dissertations

Linear feature detection in digital images is an important low-level operation in
computer vision that has many applications. In remote sensing tasks, it can be used
to extract roads, railroads, and rivers from satellite or low-resolution aerial images,
which can be used for the capture or update of data for geographic information and
navigation systems. In addition, it is useful in medical imaging for the extraction of
blood vessels from an X-ray angiography or the bones in the skull from a CT or MR
image. It also can be applied in horticulture for underground plant root detection in
minirhizotron images. …


Human Microvasculature Fabrication Using Thermal Inkjet Printing Technology, Xiaofeng Cui Dec 2008

Human Microvasculature Fabrication Using Thermal Inkjet Printing Technology, Xiaofeng Cui

All Dissertations

The current tissue engineering paradigm is that successfully engineered thick tissues must include vasculature. As biological approaches alone such as VGEF have fallen short of their promises, one may look for an engineering approach to build microvasculature. With the advent of cell printing, one may be able to build precise human microvasculature with suitable bio-ink. Human Microvascular Endothelial Cells (HMVEC) and fibrin were studied as bio-ink for microvasculature construction. Endothelial cells are the only cells to compose the human capillaries and also the major cells of blood vessel intima layer. Fibrin has been already widely recognized as tissue engineering scaffold …


Characterization Of Vascular Smooth Muscle Cell Mechanical And Frictional Properties Using Atomic Force Microscopy, Jason Hemmer Dec 2008

Characterization Of Vascular Smooth Muscle Cell Mechanical And Frictional Properties Using Atomic Force Microscopy, Jason Hemmer

All Dissertations

A working hypothesis within the Laboratory of Vascular Research is that mechanical loading on vascular smooth muscle cells (VSMCs), especially due to solid contact from endovascular devices, contributes to the development of restenosis. In order to better understand the role of mechanical loading on VSMCs in vascular disease development, it is imperative to understand the mechanical properties of VSMCs themselves. To measure the viscoelastic and frictional properties of living VSMCs in an in vitro setting, an atomic force microscope (AFM) was utilized, thereby allowing for mechanical testing of living cells in a fluid environment. In the first phase of research, …


Aperture Coupling And Penetration In Various Configurations, Jason Keen Dec 2008

Aperture Coupling And Penetration In Various Configurations, Jason Keen

All Dissertations

The problem of a slot in a perfectly conducting surface is addressed for a variety of configurations using both integral equation and transmission line techniques. The use of Bethe hole theory to model short slots is discussed and utilized where appropriate. Primary problems of discussion are a slot array, wires coupling through slots in a ground plane, and wires coupling through slots in a bent ground plane. Additionally, the use of the extended BLT formulation for incorporation of slot effects in a transmission line problem is addressed. In this manuscript, the work of Bethe is extended to include cross-aperture coupling …


Synthesis And Characterization Of Macromolecular Layers Grafted To Polymer Surfaces, Oleksandr Burtovyy Dec 2008

Synthesis And Characterization Of Macromolecular Layers Grafted To Polymer Surfaces, Oleksandr Burtovyy

All Dissertations

The composition and behavior of surfaces and interfaces play a pivotal role in dictating the overall efficiency of the majority of polymeric materials and devices. Surface properties of the materials can be altered using surface modification techniques. It is necessary to highlight that successful methods of surface modification should affect only the upper layer of the polymer material without changing bulk properties. The processes must introduce new functionalities to the surface, optimize surface roughness, lubrication, hydrophobicity, hydrophilicity, adhesion, conductivity, and/or biocompatibility.
Research presented in this dissertation is dedicated to the synthesis, characterization, and application of thin macromolecular layers anchored to …


Vascular Tissue Engineering: The Creation Of Living, Non-Thrombogenic, Functional Blood Vessels Based On Elastin Scaffolds, Aditee Kurane Dec 2008

Vascular Tissue Engineering: The Creation Of Living, Non-Thrombogenic, Functional Blood Vessels Based On Elastin Scaffolds, Aditee Kurane

All Dissertations

Cardiovascular diseases are the leading cause of death worldwide. Blood vessel replacement is a common treatment for vascular diseases such as atherosclerosis, restenosis and aneurysm, with over 300,000 bypass procedures performed each year. However, vein grafts are limited due to their availability. Although synthetic vascular replacements have been successful for large diameter arteries, they have shown minimal success in arteries with diameters <6mm. This is because most synthetic materials induce thrombus formation which, within a few months of implantation, causes failure of the vascular graft due to occlusion. Tissue engineering is a promising approach to the fabrication of non-thrombogenic vascular grafts, but a reliable and expandable cell source for tissue-engineered vascular graft (TEVG) has not been established.
The work presented here is motivated by the current unavailability of an ideal tissue engineered blood vessel replacement. Our overall goal is to create a living tissue engineered vascular graft that is biodegradable, non-thromobogenic, presents low antigenicity and …


Analysis And Design Of Interleaving Multiphase Dc-To-Dc Converter With Input Lc Filter, Kevin Thomas Delrosso Dec 2008

Analysis And Design Of Interleaving Multiphase Dc-To-Dc Converter With Input Lc Filter, Kevin Thomas Delrosso

Master's Theses

The future of microprocessors is unknown. Over the past 40 years, their historical trend has been for adopting smaller and more powerful designs that drive the world that we live in today. The state of the microprocessor business today faces a crossroad, wishing to continue on the historical trend of doubling the number of transistors on a chip every 18 months (Moore’s Law) but also facing the realistic task of needing to power these sophisticated devices. With the low voltages and high currents that are required for these microprocessors to operate, it poses a difficult task for the future designers …


Experiments And Models For The Thermal Response Of Railroad Tapered-Roller Bearings, Constantine M. Tarawneh, Kevin D. Cole, Brent M. Wilson, Fadi Alnaimat Dec 2008

Experiments And Models For The Thermal Response Of Railroad Tapered-Roller Bearings, Constantine M. Tarawneh, Kevin D. Cole, Brent M. Wilson, Fadi Alnaimat

Department of Mechanical and Materials Engineering: Faculty Publications

The need to understand and quantify the heat transfer paths within tapered-roller bearings is of great importance in the railroad industry since bearing cup temperature measurement is the primary tool utilized in the removal of distressed bearings from service. Experiments were performed to acquire temperature histories at several locations on a stationary bearing subjected to heat sources imbedded in two rollers. The experimental results were compared to zero- and first-order thermal models to estimate overall heat transfer coefficients from the bearing. The results presented here can be used to explain some of the mechanisms that lead to overheating of tapered-roller …


Gene Order Phylogeny Of The Genus Prochlorococcus, Haiwei Luo, Jian Shi, William Arndt, Jijun Tang, Robert Friedman Dec 2008

Gene Order Phylogeny Of The Genus Prochlorococcus, Haiwei Luo, Jian Shi, William Arndt, Jijun Tang, Robert Friedman

Faculty Publications

Background
Using gene order as a phylogenetic character has the potential to resolve previously unresolved species relationships. This character was used to resolve the evolutionary history within the genus Prochlorococcus, a group of marine cyanobacteria.

Methodology/Principal Findings
Orthologous gene sets and their genomic positions were identified from 12 species of Prochlorococcus and 1 outgroup species of Synechococcus. From this data, inversion and breakpoint distance-based phylogenetic trees were computed by GRAPPA and FastME. Statistical support of the resulting topology was obtained by application of a 50% jackknife resampling technique. The result was consistent and congruent with nucleotide sequence-based and gene-content based …


Hypro: A Financial Tool For Simulating Hydrogen Infrastructure Development, Brian D. James, Peter O. Schmidt, Julie Perez Dec 2008

Hypro: A Financial Tool For Simulating Hydrogen Infrastructure Development, Brian D. James, Peter O. Schmidt, Julie Perez

US Department of Energy Publications

This report summarizes an analysis of the options and trade-offs for the establishment of the hydrogen production infrastructure necessary for a complete transition to hydrogen fuel cell vehicles by the year 2050. The primary tool used for the analysis is a custom created MatLab simulation tool entitled HyPro (short for Hydrogen Production). This report describes both the calculation methodology of HyPro and the assumptions and results of the baseline analysis and its many corollary cases. This study was made possible with funding from the U.S. Department of Energy (DOE).
The report and supporting primary analyses were overseen by Fred Joseck …


Geothermal (Ground-Source) Heat Pumps: Market Status, Barriers To Adoption, And Actions To Overcome Barriers, Patrick J. Hughes Dec 2008

Geothermal (Ground-Source) Heat Pumps: Market Status, Barriers To Adoption, And Actions To Overcome Barriers, Patrick J. Hughes

US Department of Energy Publications

More effective stewardship of our resources contributes to the security, environmental sustainability, and economic well-being of the nation. Buildings present one of the best opportunities to economically reduce energy consumption and limit greenhouse gas emissions. Geothermal heat pumps (GHPs), sometimes called ground-source heat pumps, have been proven capable of producing large reductions in energy use and peak demand in buildings. However, GHPs have received little attention at the policy level as an important component of a national strategy. Have policymakers mistakenly overlooked GHPs, or are GHPs simply unable to make a major contribution to the national goals for various reasons? …