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Maximizing The Life Of A Lithium-Ion Cell By Optimization Of Charging Rates, Saeed Khaleghi Rahimian, Sean Rayman, Ralph E. White 2010 University of South Carolina

Maximizing The Life Of A Lithium-Ion Cell By Optimization Of Charging Rates, Saeed Khaleghi Rahimian, Sean Rayman, Ralph E. White

Faculty Publications

Using a dynamic optimization method, the optimum charge currents as a function of cycle number during cycling for the lithium-ion cell are obtained. A single particle physics-based model, which includes capacity fade, was applied to simulate the cell performance under low earth-orbit (LEO) cycling conditions. Useful cell life is defined as the number of cycles before the end of discharge voltage drops below 3.0 V or the cell discharge capacity becomes less than 20% of the original discharge capacity. The simulated useful cell life can be increased by ∼29.28% by varying the charge current.


Theoretical Analysis Of Stresses In A Lithium Ion Cell, Sindhuja Renganathan, Godfrey Sikha, Shriram Santhanagopalan, Ralph E. White 2010 University of South Carolina

Theoretical Analysis Of Stresses In A Lithium Ion Cell, Sindhuja Renganathan, Godfrey Sikha, Shriram Santhanagopalan, Ralph E. White

Faculty Publications

A mathematical model to simulate the generation of mechanical stress during the discharge process in a dual porous insertion electrode cell sandwich comprised of lithium cobalt oxide and carbon is presented. The model attributes stress buildup within intercalation electrodes to two different aspects: changes in the lattice volume due to intercalation and phase transformation during the charge/discharge process. The model is used to predict the influence of cell design parameters such as thickness, porosity, and particle size of the electrodes on the magnitude of stress generation. The model developed in this study can be used to understand the mechanical ...


Transmitter Optimization In Multiuser Wireless Systems With Quality Of Service Constraints, Danda B. Rawat 2010 Old Dominion University

Transmitter Optimization In Multiuser Wireless Systems With Quality Of Service Constraints, Danda B. Rawat

Electrical & Computer Engineering Theses & Disssertations

In this dissertation, transmitter adaptation for optimal resource allocation in wireless communication systems are investigated. First, a multiple access channel model is considered where many transmitters communicate with a single receiver. This scenario is a basic component of a. wireless network in which multiple users simultaneously access the resources of a wireless service provider. Adaptive algorithms for transmitter optimization to meet Quality-of-Service (QoS) requirements in a distributed manner are studied. Second, an interference channel model is considered where multiple interfering transmitter-receiver pairs co-exist such that a given transmitter communicates with its intended receiver in the presence of interference from other ...


Analysis Of Wake Vortices Of A Medium Range Twin-Propeller Military Cargo Aircraft Using Statistically Designed Experiments, Burhan Sahin 2010 Old Dominion University

Analysis Of Wake Vortices Of A Medium Range Twin-Propeller Military Cargo Aircraft Using Statistically Designed Experiments, Burhan Sahin

Mechanical & Aerospace Engineering Theses & Dissertations

An experimental study was initiated to analyze the trajectories of the streamwise vortices behind the wing tip and flap of a medium range and propeller driven twin-engine military cargo aircraft. The model used for the experimental study was a generic, high wing and half model of a propeller driven aircraft and mounted within Old Dominion University's Low Speed Wind Tunnel where the wind tunnel flow speed was set to constant value of 9 m/sec. The main purpose of the study was to reach regression models for the motion and vorticity strength of both vortices under varying factors such ...


Optimization Models And Algorithms For Spatial Scheduling, Christopher J. Garcia 2010 Old Dominion University

Optimization Models And Algorithms For Spatial Scheduling, Christopher J. Garcia

Engineering Management & Systems Engineering Theses & Dissertations

Spatial scheduling problems involve scheduling a set of activities or jobs that each require a certain amount of physical space in order to be carried out. In these problems space is a limited resource, and the job locations, orientations, and start times must be simultaneously determined. As a result, spatial scheduling problems are a particularly difficult class of scheduling problems. These problems are commonly encountered in diverse industries including shipbuilding, aircraft assembly, and supply chain management. Despite its importance, there is a relatively scarce amount of research in the area of spatial scheduling.

In this dissertation, spatial scheduling problems are ...


Solution Approximation For Atmospheric Flight Dynamics Using Volterra Theory, Ashraf Mohammed Kandeel Omran 2010 Old Dominion University

Solution Approximation For Atmospheric Flight Dynamics Using Volterra Theory, Ashraf Mohammed Kandeel Omran

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation introduces a set of novel approaches in order to facilitate and enrich Volterra theory as a nonlinear approximation technique for constructing mathematical solutions from the governing relationships describing aircraft dynamic behavior. These approaches reconnect Volterra theory and flight mechanics research, which has not been addressed in the technical literature for over twenty years. Volterra theory is known to be viable in modeling weak nonlinearities, but is not particularly well suited for directly describing high performance aircraft dynamics. In order to overcome these obstacles and restrictions of Volterra theory, the global Piecewise Volterra Approach has been developed. This new ...


Constrained Optimal Orbit Design For Earth Observation, Sharon D. Vtipil 2010 Old Dominion University

Constrained Optimal Orbit Design For Earth Observation, Sharon D. Vtipil

Mechanical & Aerospace Engineering Theses & Dissertations

The purpose of this dissertation is to demonstrate use requirements for a satellite observation mission can be used to determine a constrained optimal orbit based on observation site requirements, observation condition restraints, and sensor characteristics. The typical Earth observation satellite is first designed according to an appropriate orbit; then the observation requirements are used to develop a target schedule. The new design process outlines the development of the appropriate orbit by incorporating user requirements at the forefront of mission planning, not after an orbit has been selected. This research shows how to map the user requirements into constraints for the ...


Active Control Of Shocks And Sonic Boom Ground Signal, Bedri Yagiz 2010 Old Dominion University

Active Control Of Shocks And Sonic Boom Ground Signal, Bedri Yagiz

Mechanical & Aerospace Engineering Theses & Dissertations

The manipulation of a flow field to obtain a desired change is a much heightened subject. Active flow control has been the subject of the major research areas in fluid mechanics for the past two decades. It offers new solutions for mitigation of shock strength, sonic boom alleviation, drag minimization, reducing blade-vortex interaction noise in helicopters, stall control and the performance maximization of existing designs to meet the increasing requirements of the aircraft industries. Despite the wide variety of the potential applications of active flow control, the majority of studies have been performed at subsonic speeds. The active flow control ...


Change Orders And Lessons Learned, Paul Goodrum, Timothy R. B. Taylor, William Lester, Alex McCoy, Mohammed M. Uddin, Yongwei Shan 2010 University of Kentucky

Change Orders And Lessons Learned, Paul Goodrum, Timothy R. B. Taylor, William Lester, Alex Mccoy, Mohammed M. Uddin, Yongwei Shan

Kentucky Transportation Center Research Report

Many times, change is necessary for the success of a project. “Change, defined as any event that results in a modification of the original scope, execution time, or cost of work, happens on most projects due to the uniqueness of each project and the limited resources of time and money available for planning” (Hanna, Camlic, Peterson,& Nordheim, 2002). While change orders are necessary to address unforeseen conditions and other unavoidable or unanticipated occurrences, they tend to negatively affect construction. In most public works, change orders are the main reason for construction delays and cost overruns (Wu, Hsieh, & Cheng, 2005). Change ...


Evaluation Of Rumble Stripes, Kenneth R. Agent 2010 University of Kentucky

Evaluation Of Rumble Stripes, Kenneth R. Agent

Kentucky Transportation Center Research Report

Lane departure has been shown to be a major cause of serious traffic crashes. Installing a rumble strip on the shoulders of two lane roads provide drivers with an audible warning that they are leaving their lane of travel. Painting the edge line on the rumble strip has the possible benefit of providing more wet, nighttime delineation through the portion of the edge line painted on the sloped portion of the groove. The objectives of this study were to: a) monitor the initial installations of rumble stripes and b) evaluate the results of rumble stripe installations.

Ten rural, two-lane road ...


Electro-Osmotic Flow Over A Charged Superhydrophobic Surface, Hui Zhao 2010 University of Nevada, Las Vegas

Electro-Osmotic Flow Over A Charged Superhydrophobic Surface, Hui Zhao

Mechanical Engineering Faculty Publications

Bubbles can be trapped inside textured structures such as grooves, forming a superhydrophobic surface. A superhydrophobic surface has a large effective hydrodynamic slip length compared to a smooth hydrophobic surface and holds the promise of enhancing electrokinetic flows that find many interesting applications in microfluidics. However, recent theoretical studies suggested that electro-osmotic flows over a weakly charged superhydrophobic surface

the zeta potential of the surface is smaller than the thermal potential (25 mV) can only be enhanced when liquid-gas interfaces are charged [T. M. Squires, Phys. Fluids 20, 092105 (2008); Bahga et al., J. Fluid Mech. 644, 245 (2010)]. So ...


Technical Note: Hydraulic Property Determination Of Denitrifying Bioreactor Fill Media, Laura E. Christianson, Adrià Castelló, Reid D. Christianson, Matthew J. Helmers, Alok Bhandari 2010 Iowa State University

Technical Note: Hydraulic Property Determination Of Denitrifying Bioreactor Fill Media, Laura E. Christianson, Adrià Castelló, Reid D. Christianson, Matthew J. Helmers, Alok Bhandari

Agricultural and Biosystems Engineering Publications

Denitrification bioreactors are one of the newest options for nitrate removal in agricultural drainage waters. Optimization of denitrification bioreactor design requires the ability to identify concrete values for the hydraulic properties of bioreactor fill media. Hydraulic properties, chiefly saturated hydraulic conductivity but also porosity and particle size, are not known for many types of possible bioreactor media though they have a significant impact upon bioreactor design and performance. This work was undertaken to more fully quantify the hydraulic properties of the major type of fill media used in Iowa denitrification bioreactors through a series of porosity, hydraulic conductivity, and particle ...


Effect Of Ultrasonic Pretreatment On Methane Production Potential From Corn Ethanol Coproducts, Wei Wu-Haan, Robert T. Burns, Lara B. Moody, Cody John Hearn, David A. Grewell 2010 Iowa State University

Effect Of Ultrasonic Pretreatment On Methane Production Potential From Corn Ethanol Coproducts, Wei Wu-Haan, Robert T. Burns, Lara B. Moody, Cody John Hearn, David A. Grewell

Agricultural and Biosystems Engineering Publications

This article addresses the biochemical methane potential (BMP) production from anaerobic digestion of corn-ethanol coproducts including dried distiller grain with solubles (DDGS), distiller's wet grains (DWG), thin stillage, and condensed distiller's solubles (CDS) as well as evaluating the effects of ultrasonic pretreatment on methane production from these feedstocks. Ultrasonic pretreatment was applied with three amplitude settings of 33% (52.8 µmpp), 66% (105.6 µmpp), and 100% (160 µmpp) as well as five time settings (10, 20, 30, 40, and 50 s) to each of the four coproducts prior to conducting benchtop BMP trials. Ultrasonic pretreatment reduced mean ...


Prediction Of Indoor Climate And Long-Term Air Quality Using The Bta-Aqp Model: Part I. Bta Model Development And Evaluation, Gang Sun, Steven J. Hoff 2010 Iowa State University

Prediction Of Indoor Climate And Long-Term Air Quality Using The Bta-Aqp Model: Part I. Bta Model Development And Evaluation, Gang Sun, Steven J. Hoff

Agricultural and Biosystems Engineering Publications

The objective of this research was to develop a building thermal analysis and air quality predictive (BTA-AQP) model to predict ventilation rate, indoor temperature, and long-term air quality (NH3, H2S, and CO2 concentrations and emissions) for swine deep-pit buildings. This article, part I of II, presents a lumped capacitance model (BTA model) to predict the transient behavior of ventilation rate and indoor air temperature according to the thermo-physical properties of a typical swine building, setpoint temperature scheme, fan staging scheme, transient outside temperature, and the heat fluxes from pigs and supplemental heaters. The obtained ventilation rate and resulting indoor air ...


Livestock Grazing And Vegetative Filter Strip Buffer Effects On Runoff Sediment, Nitrate, And Phosphorus Losses, David F. Webber, Steven K. Mickelson, Syed I. Ahmed, James R. Russell, Wendy J. Powers, Richard C. Schultz, John Kovar 2010 Iowa State University

Livestock Grazing And Vegetative Filter Strip Buffer Effects On Runoff Sediment, Nitrate, And Phosphorus Losses, David F. Webber, Steven K. Mickelson, Syed I. Ahmed, James R. Russell, Wendy J. Powers, Richard C. Schultz, John Kovar

Agricultural and Biosystems Engineering Publications

Livestock grazing in the Midwestern United States can result in significant levels of runoff sediment and nutrient losses to surface water resources. Some of these contaminants can increase stream eutrophication and are suspected of contributing to hypoxic conditions in the Gulf of Mexico. This research quantified effects of livestock grazing management practices and vegetative filter strip buffers on runoff depth and mass losses of total solids, nitrate-nitrogen (NO3-N), and ortho-phosphorus (PO4-P) under natural hydrologic conditions. Runoff data were collected from 12 rainfall events during 2001 to 2003 at an Iowa State University research farm in central ...


Measurement And Modeling Of Infrared Nonlinear Absorption Coefficients And Laser-Induced Damage Thresholds In Ge And Gasb, T. J. Wagner, M. A. Bohn, Ronald A. Coutu Jr., L. P. Gonzalez, J. M. Murray, K. L. Schepler, S. Guha 2010 Air Force Institute of Technology

Measurement And Modeling Of Infrared Nonlinear Absorption Coefficients And Laser-Induced Damage Thresholds In Ge And Gasb, T. J. Wagner, M. A. Bohn, Ronald A. Coutu Jr., L. P. Gonzalez, J. M. Murray, K. L. Schepler, S. Guha

Electrical and Computer Engineering Faculty Research and Publications

Using a simultaneous fitting technique to extract nonlinear absorption coefficients from data at two pulse widths, we measure two-photon and free-carrier absorption coefficients for Ge and GaSb at 2.05 and 2.5 μm for the first time, to our knowledge. Results agreed well with published theory. Single-shot damage thresholds were also measured at 2.5 μm and agreed well with modeled thresholds using experimentally determined parameters including nonlinear absorption coefficients and temperature dependent linear absorption. The damage threshold for a single-layer Al2O3 anti-reflective coating on Ge was 55% or 35% lower than the uncoated threshold for ...


Evaluation Of Ultrasonic Pretreatment On Anaerobic Digestion Of Different Animal Manures, Wei Wu-haan, Robert T. Burns, Lara B. Moody, David A. Grewell, D. Raj Raman 2010 Iowa State University

Evaluation Of Ultrasonic Pretreatment On Anaerobic Digestion Of Different Animal Manures, Wei Wu-Haan, Robert T. Burns, Lara B. Moody, David A. Grewell, D. Raj Raman

Agricultural and Biosystems Engineering Publications

This article addresses the effect of ultrasonication as a pretreatment to anaerobic digestion of four types of animal manure, including swine slurry, beef feedlot manure, dairy manure slurry, and separated dairy manure effluent. The effect of ultrasonication on soluble chemical oxygen demand (SCOD) and biochemical methane potential (BMP) were determined, and the energy efficiency of ultrasonic pretreatment was evaluated. Ultrasonic pretreatment was applied at two amplitudes (80 and 160 µmpp) and at two time settings (15 and 30 s) to each of the four manure types. The SCOD of each manure sample was determined before and after ultrasonic pretreatment. In ...


Effect Of Ammonia Soaking Pretreatment And Enzyme Addition On Biochemical Methane Potential Of Switchgrass, Jennifer Nicole Himmelsbach, D. Raj Raman, Robert P. Anex, Robert T. Burns, Carol Rose Faulhaber 2010 Iowa State University

Effect Of Ammonia Soaking Pretreatment And Enzyme Addition On Biochemical Methane Potential Of Switchgrass, Jennifer Nicole Himmelsbach, D. Raj Raman, Robert P. Anex, Robert T. Burns, Carol Rose Faulhaber

Agricultural and Biosystems Engineering Publications

This article presents the biochemical methane potential (BMP) results from the anaerobic digestion (AD) of switchgrass. Triplicate BMP assays were performed on: untreated switchgrass, aqueous ammonia soaking (AAS) pretreated switchgrass (soaked in 29.5% reagent-grade aqueous ammonia at 5 L kg-1 switchgrass for 5 d), and AAS-pretreated switchgrass plus cellulytic enzymes at 12.5, 25, 62.5, and 125 filter paper units (FPU) enzyme g-1 volatile solids (VS). Biogas production and biogas methane content were measured daily in all treatments for 21 d. Both biogas and corrected methane production varied significantly among treatments, especially during the first 7 d of ...


Laboratory Scale Evaluation Of Volatile Organic Compound Emissions As Indication Of Swine Carcass Degradation Inside Biosecure Composting Units, Neslihan Akdeniz, Jacek A. Koziel, Hee-Kwon Ahn, Thomas D. Glanville, Benjamin P. Crawford, D. Raj Raman 2010 Iowa State University

Laboratory Scale Evaluation Of Volatile Organic Compound Emissions As Indication Of Swine Carcass Degradation Inside Biosecure Composting Units, Neslihan Akdeniz, Jacek A. Koziel, Hee-Kwon Ahn, Thomas D. Glanville, Benjamin P. Crawford, D. Raj Raman

Agricultural and Biosystems Engineering Publications

Biosecure livestock mortality composting systems have been used to dispose of diseased livestock mortalities. In those types of system, visual inspection of carcass degradation is not possible and monitoring VOCs (volatile organic compounds) released by carcasses is a new approach to assess progress of the composting process. In this study, field-scale livestock mortality composting systems were simulated and a laboratory scale composting system with aerobic and anaerobic test units was designed to collect VOC samples from the headspace of decaying plant materials (70 g dry weight) and swine tissues (70 g dry weight) at controlled operating temperatures. Headspace samples were ...


Production And Characterization Of Novel Air Filtration Media, Elizabeth Skomra 2010 Clemson University

Production And Characterization Of Novel Air Filtration Media, Elizabeth Skomra

All Dissertations

HEPA and ULPA filtration systems have proven to be an advantageous instrument in removing common contaminants from the air. However, an increased pressure drop due to the build-up of particulates on the filters results in its inevitable decrease in performance. Improving current filtration systems would include increasing collection efficiency all the while either maintaining or reducing the differential pressure drop in order to extend the life of the filter. One method of improving collection efficiency would be viable by increasing the amount of surface area within the filter media by glass fibers because of their inherent quality of being smaller ...


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