Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

2010

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 451 - 480 of 24178

Full-Text Articles in Entire DC Network

Evaluating Interactions Of Task Relevance And Visual Attention In Driver Multitasking, Teena Marie Garrison Dec 2010

Evaluating Interactions Of Task Relevance And Visual Attention In Driver Multitasking, Teena Marie Garrison

Theses and Dissertations

Use of cellular phones while driving, and safety implications thereof, has captured public and scientific interest. Previous research has shown that driver reactions and attention are impacted by cellular phone use. Generally, previous research studies have not focused on how visual attention and driver performance may interact. Strayer and colleagues found lower recognition for items present in the driving environment when drivers were using a cellular phone than when not using the phone; however, the tested items were not directly relevant to driving. Relevance to driving may have an impact on attention allocation. The current project used a mediumidelity driving …

Go to article

A Concept Mapping Case Domain Modeling Approach For Digital Forensic Investigations, April L. Tanner Dec 2010

A Concept Mapping Case Domain Modeling Approach For Digital Forensic Investigations, April L. Tanner

Theses and Dissertations

Over the decades, computer forensics has expanded from primarily examining computer evidence found on hard drives into the examination of digital devices with increasing storage capacity, to the identification of crimes and illegal activities involving the use of computers, to addressing standards and practices deficiencies, and to addressing the need to educate and train law enforcement, computer forensic technicians, and investigators. This dissertation presents the concept mapping case domain modeling approach to aid examiners/investigators in searching and identifying digital evidence and analyzing the case domain during the examination and analysis phase of the computer forensic investigation. The examination and analysis …

Go to article

Decay And Environmental Studies On Southern Pine, Joseph Martin Dahlen Dec 2010

Decay And Environmental Studies On Southern Pine, Joseph Martin Dahlen

Theses and Dissertations

This work focused on decay and dimensional stability of southern pine lumber and environmental issues associated with emissions released during kiln drying of southern pine. In one study decking boards were treated with a 3% resin acid solution to increase the dimensional stability. The boards were placed on a roof and weathered for two years. The increased water repellency reduced moisture gain following summer rainstorms by one-third compared to untreated matched samples, this significantly reduced splitting by half and cupping by one-third. In one study decking boards from matched samples were weathered for two years in the roof setup described …

Go to article

Density Functional Theory And Modified Embedded-Atom Method: Applications To Steel, Magnesium Alloys, And Semiconductor Surfaces, Jeff Lynn Houze Dec 2010

Density Functional Theory And Modified Embedded-Atom Method: Applications To Steel, Magnesium Alloys, And Semiconductor Surfaces, Jeff Lynn Houze

Theses and Dissertations

We performed atomistic modeling to study structural and mechanical properties of materials. We used density functional theory (DFT) for all the studies presented and constructed a method for quickly optimizing semi-empirical modified embedded atom method (MEAM) potentials. In our first study, we show that the reconstruction model in the literature for GaSb(001) is not predicted to have the lowest surface reconstruction energy. A modification was proposed that improves the energy. The second study tries to validate a crystal structure for the Φ Phase of Al-Mg-Zn. The third study deals with plain carbon steel, including some microalloying of Vanadium and vacancy …

Go to article

Detection And Characterization Of A Volatile Compound As A Response To Fall Armyworm (Spodoptera Frugiperda) Feeding In Maize (Zea Mays), Whitney Elizabeth Crow Smith Dec 2010

Detection And Characterization Of A Volatile Compound As A Response To Fall Armyworm (Spodoptera Frugiperda) Feeding In Maize (Zea Mays), Whitney Elizabeth Crow Smith

Theses and Dissertations

Maize (Zea mays) is an important agricultural crop frequently targeted by pests that pose a threat to plant development and survival. To deal with this problem, maize generates a wide variety of responses to attack by pests, from activation of woundresponse pathways to the release of volatile compounds. Several maize lines have been developed that show resistance to one common pest, the larvae of the fall armyworm (Spodoptera frugiperda). Analysis of the volatiles released by the resistant and susceptible lines in the presence and absence of the fall armyworm was conducted using SPME coupled to GC/MS. Caryophyllene, a commonly released …

Go to article

Development Of A Macrostructural Model For Studying The Combined Effects Of Plasticity And Roughness Induced Crack Closure, Justin Mandel Crapps Dec 2010

Development Of A Macrostructural Model For Studying The Combined Effects Of Plasticity And Roughness Induced Crack Closure, Justin Mandel Crapps

Theses and Dissertations

A weight function based modified strip-yield model is adapted to include the mode I effects of roughness induced crack closure. The weight function methodology is verified for arbitrary mixed mode loading conditions under load levels experienced in fatigue crack growth. A rough crack geometry is simulated as a sine wave fitted to a sawtooth defined by an asperity angle and period. Additional mode I crack closure due to mode II sliding of crack faces is calculated and incorporated into the strip-yield model by lengthening and shortening the crack face elements. Simulations of fatigue crack growth using the newly developed model …

Go to article

Development Of Current Injection Based Three Phase Unbalanced Continuation Power Flow For Distribution System, Shilpa Toppo Dec 2010

Development Of Current Injection Based Three Phase Unbalanced Continuation Power Flow For Distribution System, Shilpa Toppo

Theses and Dissertations

Voltage stability studies (VSS) of the electric network is a crucial factor to make the system operate in stable region and to prevent power blackouts. There are several commercial tools available for VSS of electric transmission systems (TS) but not many for distribution systems (DS). With increasing penetration of distributed renewable generations and meshed network within DS, shipboard power system (SPS) and microgrid, these VSS tools need to be extended for DS. Due to inherent characteristic like high R/X ratio, three phase and unbalanced operation, DS or SPS requires different mathematical approach than TS. Unbalanced three phase power flow and …

Go to article

Distributed State Estimation With Phasor Measurement Units (Pmu) For Power Systems, Qinghua Huang Dec 2010

Distributed State Estimation With Phasor Measurement Units (Pmu) For Power Systems, Qinghua Huang

Theses and Dissertations

Wide-area monitoring for the power system is a key tool for preventing the power system from system wide failure. State Estimation (SE) is an essential and practical monitoring tool that has been widely used to provide estimated values for each quantity within energy management systems (EMS) in the control center. However, monitoring larger power systems coordinated by regional transmission operators has placed an enormous operational burden on current SE techniques. A distributed state estimation (DSE) algorithm with a hierarchical structure designed for the power system industry is much more computationally efficient and robust especially for monitoring a wide-area power system. …

Go to article

Gasoline-Range Hydrocarbons Produced From Three Types Of Synthesis Gas Using A Mo/Hzsm-5 Catalyst, Jason Tyler Street Dec 2010

Gasoline-Range Hydrocarbons Produced From Three Types Of Synthesis Gas Using A Mo/Hzsm-5 Catalyst, Jason Tyler Street

Theses and Dissertations

Biomass-derived hydrocarbons that include gasoline, diesel, and jet fuel will help replace finite fossil fuel hydrocarbons of the same range. This study showed that temperature could be controlled in a scaled-up reactor system using three types of syngas. The CO conversion, selectivity and amount of product created from each type of syngas were examined. Clean syngas composed of 40% H2, 20% CO, 12% CO2, 2% CH4, and 26 % N2 was used to test ideal stoichiometric molar values. Clean syngas composed of 19% H2, 20% CO, 12% CO2, 2% CH4, and 47 % N2 was used to test an ideal …

Go to article

Helping Prepare Community College Students To Make The Transition From College To Work, Lagena Arlette Bradley Dec 2010

Helping Prepare Community College Students To Make The Transition From College To Work, Lagena Arlette Bradley

Theses and Dissertations

The purpose of the study was to investigate students’ perceptions about the need for more student training on making the transition from community college enrollment to employment. The hypothesis was that community college students would perceive that additional career counseling services would help them transition successfully into the world of work. Examination of students’ thoughts about career counseling services assisted in finding factors that facilitate and impede students’ desires for career counseling services including career courses. A researcher-developed pen and paper self-report survey instrument was administered to students enrolled in English courses at Meridian Community College during the 2009 fall …

Go to article

Influence Of Soil Properties On The Aboveground Blast Environment From A Near-Surface Detonation, John Q. Ehrgott Dec 2010

Influence Of Soil Properties On The Aboveground Blast Environment From A Near-Surface Detonation, John Q. Ehrgott

Theses and Dissertations

Detonation of an explosive charge, such as a mine or an improvised explosive device (IED) at the ground surface or buried at shallow depth in soil, can produce high airblast pressures and significant dynamic soil debris loads on an overlying or nearby structure, such as a vehicle passing over the explosive. The blast loading environment is a function of many factors including the explosive type, configuration, mass, and depth of burial, soil characteristics, and the distance between the ground surface and the structure or object. During the past several years, the US Army has focused considerable attention on developing improved …

Go to article

Kindergarten Through Third Grade Reading Tutors In Northeast Mississippi, Angela Williams Dec 2010

Kindergarten Through Third Grade Reading Tutors In Northeast Mississippi, Angela Williams

Theses and Dissertations

All public schools in the United States have been caught up in educational reform. This has especially been true since the 1980’s. The No Child Left Behind Act of 2001 was a major component in how schools have changed the process of educating students. In response to reform efforts, many schools have relied on their own knowledge to achieve higher test scores. In the last several years, accountability standards have been increasing. Schools are being assessed according to national standards. Because of this, many schools are using different methods of instruction for students at-risk of failing. One method of instruction …

Go to article

Poplar Interactions With Zinc For Use In Bioremediation And Monitoring, Joshua Pope Adams Dec 2010

Poplar Interactions With Zinc For Use In Bioremediation And Monitoring, Joshua Pope Adams

Theses and Dissertations

Plant mechanisms regulating environmental heavy metal interactions are vital for plant survival. Plants must maintain adequate metal levels while preventing excesses. Several mechanisms involved in heavy metal uptake and sequestration have been identified and studied in hyperaccumulating plants such as Thlaspi caerulescens. These plants accumulate large quantities of metals, but their use in remediation is limited by their small size. On the other hand, mechanisms in high-biomass, non-hyperaccumulating perennial species such as poplar (Populus spp.) are unknown. The central goal of this project is to delineate specific mechanisms in poplar regulating the heavy metal zinc (Zn) for potential use in …

Go to article

Reaction Of Bio-Oil With Alcohols: Effect On Long Term Stability And Properties Of Bio-Oil For Use As Fuel, Priyanka Bhattacharya Dec 2010

Reaction Of Bio-Oil With Alcohols: Effect On Long Term Stability And Properties Of Bio-Oil For Use As Fuel, Priyanka Bhattacharya

Theses and Dissertations

Bio-oil is produced by the rapid pyrolysis of biomass and is a source of renewable fuel. The increase in viscosity during storage is a major problem that can be controlled by the addition of methanol or other alcohols. The objective of this research was to determine how alcohols stabilize bio-oil by investigating the reactions of alcohols with low molecular weight aldehydes and acids. The reaction of methanol with hydroxyacetaldehyde (HA) and acetic acid to form the respective acetal or ester was catalyzed by the 7 x 10-4 M strong acids such as sulfuric, hydrochloric, p-toluene sulfonic acid, and methylsulfonic acid. …

Go to article

Investigations Of Factors Affecting Pine And Cottonwood Pyrolysis Oil Aging, Caitlin Durnin Naske Dec 2010

Investigations Of Factors Affecting Pine And Cottonwood Pyrolysis Oil Aging, Caitlin Durnin Naske

Theses and Dissertations

Studies of aging processes were conducted on pyrolysis oils produced from pine and cottonwood biomass (clear wood, whole tree, bark and needles/leaves). Accelerated aging at 80 °C for up to 504 h was employed to investigate the short and long-term effects of feedstock, phase separation, char particulates, and solvent addition on pyrolysis oil properties. Feedstock containing forestry residue was found to increase water content of neat pyrolysis oil and the collection method (total vs. fractionated) affects all of the properties with the largest impact on viscosity and as produced molecular weight. Post-condensation liquid filtration did not prevent aging-related water content …

Go to article

Microstructure-Based Multistage Fatigue Characterization And Modeling Of An Acrylonitrile Butadiene Styrene Copolymer, Jason Elvin Fountain Dec 2010

Microstructure-Based Multistage Fatigue Characterization And Modeling Of An Acrylonitrile Butadiene Styrene Copolymer, Jason Elvin Fountain

Theses and Dissertations

In this work, fatigue experiments and observations are used to experimentally and computationally quantify fatigue structure-property relationships and then capture these effects through a microstructure-based MultiStage Fatigue (MSF) model for a thermoplastic Acrylonitrile Butadiene Styrene copolymer. Completely reversed fatigue experiments were conducted over a range of strain amplitudes at two frequencies (1 Hz and 10 Hz). Scanning electron microscopy of fatigue fracture surfaces was used to quantify the microstructural notch root or initiating particle size for structure-property relations. Results were then processed in an MSF model sensitive to microstructural effects to capture the fatigue lifetimes for the thermoplastic ABS copolymer.

Go to article

Physical And Mechanical Properties Evaluations Of A New Engineered Wood Product, Jonathan Michael Linton Dec 2010

Physical And Mechanical Properties Evaluations Of A New Engineered Wood Product, Jonathan Michael Linton

Theses and Dissertations

Finding alternative uses for small diameter raw materials is a critical problem throughout the United States. Insufficient markets for small diameter, southern yellow pine (Pinus spp.) trees from first plantation thinnings are impacting silvicultural practices on millions of acres of land. In western states, the lack of markets for small diameter ponderosa pine (Pinus ponderosa) and lodgepole pine (Pinus contorta) creates multiple problems in terms of excess material in the forest. This excess material enhances fire potential and reduces land management practices. This research deals with a new structural composite from small diameter raw logs using a technology called steampressed …

Go to article

Production Of Second Generation Biofuels From Woody Biomass, Sanjeev Kumar Gajjela Dec 2010

Production Of Second Generation Biofuels From Woody Biomass, Sanjeev Kumar Gajjela

Theses and Dissertations

Increased research efforts have recently been accelerated to develop liquid transportation fuels from bio-oil produced by fast pyrolysis. However, these bio-oils contain high levels of oxygenated compounds that require removal to produce viable transportation fuels. A variety of upgrading technologies have been proposed, of which catalytic hydroprocessing of the raw bio-oil has appears to have the best potential due to the fact that no fractionation of the bio-oil is required prior to treatment. The objective of this research was to apply two-stage catalytic hydroprocessing to bio-oil with heterogeneous catalysts to produce hydrocarbon fuels. To achieve this objective seven catalysts were …

Go to article

Evolution Of The Protein-Coding Genes In The Genomes Of The Mycoplasmatales, Dipaloke Mukherjee Dec 2010

Evolution Of The Protein-Coding Genes In The Genomes Of The Mycoplasmatales, Dipaloke Mukherjee

Theses and Dissertations

The bacterial species belonging to the order Mycoplasmatales have highly truncated genomes, and are thus ideal for studying genome evolution patterns. Fourteen members (twelve species) of this order were selected for study of genome evolution based on gene function and phylogeny. A database was constructed that consisting of the set of genes that are common to all of these species, and these genes were further subdivided based on their functions. A Bayesian phylogenetic tree was also constructed from the 16 S ribosomal DNA sequences from these species and robust clades were identified for testing the influence of selection on gene …

Go to article

Full-Scale Evaluation Of Matting Systems For Temporary Roads, Timothy Wallace Rushing Dec 2010

Full-Scale Evaluation Of Matting Systems For Temporary Roads, Timothy Wallace Rushing

Theses and Dissertations

An evaluation of eleven roadway matting systems was conducted to determine their effectiveness in carrying heavy vehicle traffic over loose sand subgrades. Three of the eleven matting systems were also evaluated over soft fine-grained subgrades. Matting products included high-density polyethylene, aluminum, fiberglass, and polyester. System configurations included continuous rolls of material, segmented rolls, and individual panels. The matting products were assembled on test sections and trafficked with a 7-ton, 6-wheeled truck loaded with a 7-ton payload until 20 percent of the mat section was no longer reusable or 2,000 truck passes were achieved. Earth pressure cells were installed under nine …

Go to article

Identification Of Measurement Technology For Online Recording Of Transients In Underground Residential Distribution System, Balaji Pushpanathan Dec 2010

Identification Of Measurement Technology For Online Recording Of Transients In Underground Residential Distribution System, Balaji Pushpanathan

Theses and Dissertations

Underground Residential Distribution (URD) power cables are aged due to electrical, thermal, mechanical, and environmental stresses during their service. The recent dielectric conditions of the cables are of much interest for utilities. The existing offline diagnostic method requires forceful disconnection of the URD cable for maintenance. Online recording and Fast Fourier Transform analysis of intentionally created transients in URD is one of the promising method to assess the current condition of the cable. For the bigger goal of developing an online power cable condition assessment, the measurement techniques which are required to be implemented has to be evaluated. In order …

Go to article

4-D Modeling Of Displacement Vector Fields For Improved Radiation Therapy, Elizabeth Zachariah Dec 2010

4-D Modeling Of Displacement Vector Fields For Improved Radiation Therapy, Elizabeth Zachariah

Theses and Dissertations

In radiation therapy, it is imperative to deliver high doses of radiation to the tumor while reducing radiation to the healthy tissue. Respiratory motion is the most significant source of errors during treatment. Therefore, it is essential to accurately model respiratory motion for precise and effective radiation delivery. Many approaches exist to account for respiratory motion, such as controlled breath hold and respiratory gating, and they have been relatively successful. They still present many drawbacks. Thus, research has been expanded to tumor tracking. This paper presents a spatio-temporal model for four dimensional CT reconstruction. The method begins with a set …

Go to article

2010-12-10, Board Of Regents, Murray State University Dec 2010

2010-12-10, Board Of Regents, Murray State University

Board of Regents Meeting Minutes

No abstract provided.

Go to article

Navigation With Limited Prior Information Using Time Difference Of Arrival Measurements From Signals Of Opportunity, Christopher M. Rondeau Dec 2010

Navigation With Limited Prior Information Using Time Difference Of Arrival Measurements From Signals Of Opportunity, Christopher M. Rondeau

Theses and Dissertations

The Global Positioning System (GPS) provides world-wide availability to high-accuracy navigation and positioning information. However, the threats to GPS are increasing, and many limitations of GPS are being encountered. Simultaneously, systems previously considered as viable backups or supplements to GPS are being shut down. This creates the need for system alternatives. Navigation using signals of opportunity (SoOP) exploits any signal that is available in a given area, regardless of whether or not the original intent of the signal was for navigation. Common techniques to compute a position estimate using SoOP include received signal strength, angle of arrival, time of arrival, …

Go to article

Fatigue Behavior Of A Sic/Sic Composite At 1000⁰C In Air And In Steam, Michael W. Knauf Dec 2010

Fatigue Behavior Of A Sic/Sic Composite At 1000⁰C In Air And In Steam, Michael W. Knauf

Theses and Dissertations

Tension-tension fatigue behavior of a prototype Silicon Carbide/Silicon Carbide (SiC/SiC) ceramic matrix composite (CMC) material was investigated at 1000°C in laboratory air and in steam environments. The material consists of a SiC matrix reinforced with CG NICALON™ fibers woven in an eight harness satin weave (8HSW) and coated with a BN/SiC dual-layer interphase. The composite was manufactured by a Polymer Infiltration and Pyrolysis (PIP) process. A seal coat of SiC and elemental boron was applied to the test specimens after machining. The tensile stress-strain behavior was investigated and the tensile properties were measured at 1000°C. Tension-tension fatigue behavior was studied …

Go to article

Flow Control Application On A Submerged Inlet Characterized By Three-Component Ldv, Tina H. Reynolds Dec 2010

Flow Control Application On A Submerged Inlet Characterized By Three-Component Ldv, Tina H. Reynolds

Theses and Dissertations

A submerged inlet investigation, using flow control in the form of discrete blowing, examined proximity and jet directionality to improve compressor face uniformity. The flow control locations were at the head of the ramp and part way down the ramp, providing four configurations under examination. Laser Doppler velocimetry (LDV)measurements at the throat determined the effect of the flow control based on the statistical velocity measurements. Blowing at closer proximity to the throat and targeting the largest velocity deficit region provided the best results. The airspeed and inlet velocity simulated takeoff and landing conditions; velocities ranged from Mach 0.1-0.3 at the …

Go to article

Performance Characterization Of A Three-Axis Hall Effect Thruster, Spencer E. Temkin Dec 2010

Performance Characterization Of A Three-Axis Hall Effect Thruster, Spencer E. Temkin

Theses and Dissertations

No abstract provided.

Go to article

Effects Of Prior Aging At 274⁰C In Argon On Inelastic Deformation Behavior Of Pmr-15 Polymer At 288⁰C: Experiment And Modeling, Joseph A. Wahlquist Dec 2010

Effects Of Prior Aging At 274⁰C In Argon On Inelastic Deformation Behavior Of Pmr-15 Polymer At 288⁰C: Experiment And Modeling, Joseph A. Wahlquist

Theses and Dissertations

No abstract provided.

Go to article

Network Security Toolkit Including Heuristic Solutions For Trust System Placement And Network Obfuscation, Gabriel H. Greve Dec 2010

Network Security Toolkit Including Heuristic Solutions For Trust System Placement And Network Obfuscation, Gabriel H. Greve

Theses and Dissertations

For Part I, a supervisory control and data acquisition (SCADA) network consists of a group stations and substations in a portion of the power grid. The use of Internet technology in SCADA communications as well as other factors has caused vulnerabilities. One idea to help mitigate this risk is to strategically place trust nodes to compartmentalize and secure the SCADA systems without disturbing its finely honed processes. The trust nodes combine firewall and intrusion detection technology to provide more secure communication. An optimal solution to this problem has already been developed using a mixed-integer linear programming model. Because the problem …

Go to article

A Linear Combination Of Heuristics Approach To Spatial Sampling Hyperspectral Data For Target Tracking, Barry R. Secrest Dec 2010

A Linear Combination Of Heuristics Approach To Spatial Sampling Hyperspectral Data For Target Tracking, Barry R. Secrest

Theses and Dissertations

Persistent surveillance of the battlespace results in better battlespace awareness which aids in obtaining air superiority, winning battles, and saving friendly lives. Although hyperspectral imagery (HSI) data has proven useful for discriminating targets, it presents many challenges as a useful tool in persistent surveillance. A new sensor under development has the potential of overcoming these challenges and transforming our persistent surveillance capability by providing HSI data for a limited number of pixels and grayscale video for the remainder. The challenge of exploiting this new sensor is determining where the HSI data in the sensor's field of view will be the …

Go to article

First Prev Next Last