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

Physical Sciences and Mathematics Commons

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

Articles 1 - 22 of 22

Full-Text Articles in Physical Sciences and Mathematics

Analysis Of Expedient Field Decontamination Methods For The Xmx/2l-Mil High-Volume Aerosol Sampler, Brandon C. Laroche Dec 2009

Analysis Of Expedient Field Decontamination Methods For The Xmx/2l-Mil High-Volume Aerosol Sampler, Brandon C. Laroche

Theses and Dissertations

The XMX/2L-MIL is a high volume air sampler used by the Air Force Bioenvironmental Engineering community to collect biological aerosols. Without a verified decontamination technique, however, the XMX cannot be used effectively. The objective of this study was to evaluate several proposed methods for expedient field decontamination of the XMX. This study centered on the inactivation of Bacillus atrophaeus spores and vegetative Erwinia herbicola organisms from the XMX inner canister. The goals in this investigation were twofold: 1) to verify the antimicrobial efficacy of a 10% bleach solution and 2) to determine if wiping the components with a bleach-soaked paper …


Factors Limiting Benthic Algal Abundance In Virginia Streams Of The Coastal Plain, Michael Brandt Jul 2009

Factors Limiting Benthic Algal Abundance In Virginia Streams Of The Coastal Plain, Michael Brandt

Theses and Dissertations

Algae are important components of stream food webs and often used in biomonitoring assessments. Little is known regarding the factors that limit their abundance in streams of the VA Coastal Plain. The surficial geology of the Coastal Plain is predominately sandy deposits which comprise the dominant substrate in streams of this region. In a comparative study of five streams located near the VCU Rice Center, we quantified substrate composition, light availability, and nutrient concentrations to assess their relative importance in determining benthic algal abundance. The proportion of stream area comprised of hard substrates was a significant predictor of variation in …


Shrinking The Janzen-Connell Doughnut: Consequences Of An Invasive Multiplier (Microstegium Vimineum) On The Mid-Canopy In A Mixed Pine-Oak Forest, Rebekha Shaw May 2009

Shrinking The Janzen-Connell Doughnut: Consequences Of An Invasive Multiplier (Microstegium Vimineum) On The Mid-Canopy In A Mixed Pine-Oak Forest, Rebekha Shaw

Theses and Dissertations

Introduction of invasive species can alter seed fate predictions made by the Janzen-Connell Escape Hypothesis (JCEH). The JCEH states that there is a suitable region around a plant that is ideal for seed germination, growth, and recruitment. Seeds dispersed too close to the maternal plant are subject to competition from the maternal individual and perhaps density-dependent predation, whereas seeds dispersed further away may end up in suboptimal habitats. Invasive species may change the amount of these suitable habitats for native plants by creating unsuitable light environments and as a result, may influence the size of the ideal recruitment zone surrounding …


Construction Site Sedimentary Pollution In A Watershed, Imo Okwu May 2009

Construction Site Sedimentary Pollution In A Watershed, Imo Okwu

Theses and Dissertations

In the study of sediment pollution on and near a construction site, it is necessary to remember that sediment movement and deposition are part of the natural environment before the intervention of construction. As with many hydrologic problems, most sedimentation problems have visual impacts for relatively short periods, because they are rainstorm-related. Perhaps the most serious sedimentation problem is general deterioration of the total environment, a condition usually not recognized by the public. This research presents an analytical evaluation of five construction sites. The analytical framework categorized the life cycle of construction sites into three stages in order to facilitate …


Habitat Suitability Criteria For Fishes Of The South Fork Of The Shenandoah River And An Investigation Into Observer Effects Associated With Two Techniques Of Direct Underwater Observation, Robert Clayton Ramey Apr 2009

Habitat Suitability Criteria For Fishes Of The South Fork Of The Shenandoah River And An Investigation Into Observer Effects Associated With Two Techniques Of Direct Underwater Observation, Robert Clayton Ramey

Theses and Dissertations

This study constructed habitat suitability criteria for fishes of the South Fork of the Shenandoah River, in Virginia. The criteria will be used in an IFIM study to produce estimates of the discharge required by fishes in the South Fork. Chi-square tests were used to evaluate whether criteria described habitat use to a statistically significant degree. Secondly, chi-square tests were used to test transferability. The criteria described the habitat use of seven taxa commonly found in the South Fork to a statistically significant degree. Habitat criteria for two taxa did not describe their habitat use to a statistically significant degree. …


An Environmental And Economic Assessment Of Future Municipal Solid Waste Disposal: A Case Study Of Select High Growth Regions Of Virginia., Joseph Krouse Apr 2009

An Environmental And Economic Assessment Of Future Municipal Solid Waste Disposal: A Case Study Of Select High Growth Regions Of Virginia., Joseph Krouse

Theses and Dissertations

This research analyzed environmental and economic factors associated with municipal solid waste (MSW) management of select high growth Planning District Commissions (PDCs) of Virginia. Current MSW management scenarios were compared to future hypothetical scenarios utilizing a regional landfill or waste-to-energy (WTE) combustion facility. Life-cycle inventory and full cost accounting methods of the Municipal Solid Waste Decision Support Tool, developed by the Environmental Protection Agency (EPA), were utilized to estimate annualized environmental emissions and economic costs. Model results and analysis indicate that a regional landfill would be the least cost intensive MSW management strategy in comparison to current management methods; however …


Hyperspectral Reflectance For Rapid Viability Assessment Of Bacillus Endospores, Jarrod Edwards Apr 2009

Hyperspectral Reflectance For Rapid Viability Assessment Of Bacillus Endospores, Jarrod Edwards

Theses and Dissertations

A study was conducted to optically determine the viability of the Gram +, endospore-forming bacterial genera Bacillus using a hyperspectral reflectance spectrometer. Endospores are a dormant, differentiated cellular capsule form taken by select bacteria to ensure survival when environmental conditions become unfavorable. Two species of Bacillus were used for this study, Bacillus megaterium and Bacillus subtilis. These endospores were killed using a chemical treatment of sodium hypochlorite or a physical treatment of heat and pressure in an autoclave. The treated samples along with viable samples were lyophilized to form a powder. A reflectance spectrometer measuring 350 nm to 2500 nm …


Elemental Composition And Nutrient Effect On The Uptake And Metabolism Of Dissolved Organic Carbon By Bacteria From A Temperate Region River, Anne Stuart Apr 2009

Elemental Composition And Nutrient Effect On The Uptake And Metabolism Of Dissolved Organic Carbon By Bacteria From A Temperate Region River, Anne Stuart

Theses and Dissertations

Rivers are arteries that connect land and sea, and provide a conduit and reactor for allochthonous and autochthonous organic carbon sources (OC) delivered to the coastal ocean. In comparison to marine waters, inland waters quantitatively represent only a fraction of the marine system; however, their importance to global C cycling maybe disproportional to its actual size. Inland systems are subject to multiple sources of OC (autochthonous and allochthonous) that vary individually in space and time with respect to their concentration and potential bacterial bioavailability. This study investigates the impact of high and ambient inorganic nutrient concentrations on the bacterial bioavailability …


The Responses Of Blue Crabs (Callinectes Sapidus) To Hypoxia/Hypercapnia In Freshwater, James Martin Apr 2009

The Responses Of Blue Crabs (Callinectes Sapidus) To Hypoxia/Hypercapnia In Freshwater, James Martin

Theses and Dissertations

The present research examined respiratory responses of blue crabs to long term (4, 13, and 21 days) hypercapnic hypoxia in freshwater at 23 C. Hypoxic conditions (50-60 & 75-85 mmHg O2) were induced by allowing the crabs to consume their oxygen supply, resulting in a hypercapnic induced decrease in pH that remained through the exposure. Postbranchial hemolymph responses to hypoxia/hypercapnia in freshwater demonstrate decreases in PO2, increases in PCO2, and decreases in pH. Lactate levels decreased over time, but hemocyanin concentration was highly variable with no trends. PH, lactate, and hemocyanin observations also demonstrated high variability and a variety of …


Role Of Bcl-2 Family Members To Promote Glucocorticoid –Induced Apoptosis By Mek Inhibitors In Leukemic Cells, Anila Rambal Apr 2009

Role Of Bcl-2 Family Members To Promote Glucocorticoid –Induced Apoptosis By Mek Inhibitors In Leukemic Cells, Anila Rambal

Theses and Dissertations

Glucocorticoids (GC) are common components of many chemotherapeutic regimens for lymphoid malignancies. GC-induced apoptosis involves an intrinsic BCL-2 family-regulated pathway. It has been shown that BIM (BCL-2 interacting mediator of cell death), a BH3-only pro-apoptotic protein, is up-regulated by dexamethasone (Dex) treatment in acute lymphoblastic leukemia (ALL) cells. Furthermore, BIM is inactivated by extracellular signal-regulated kinase (ERK)-mediated phosphorylation. We therefore hypothesized co-treatment with Dex and MEK/ERK inhibitors would promote apoptosis in ALL cells through BIM up-regulation and activation. We show here that a MEK inhibitor, PD184352 synergistically enhances Dex lethality in CCRF-CEM (T-ALL) cells. Co-treatment with Dex and PD184352 results …


Patterns Of Abundance Across An Urban-Rural Gradient For Commonly Found Indigenous Arthropods, David Jones Apr 2009

Patterns Of Abundance Across An Urban-Rural Gradient For Commonly Found Indigenous Arthropods, David Jones

Theses and Dissertations

Abstract Proof of concept for a continuous environmental sampling methodology that employs common terrestrial arthropods as environmental samplers was tested by analyzing pitfall, malaise and black light captures over a six month period over a replicated urban-suburban-rural gradient in Central Virginia. All arthropods captured at the nine sites were identified and assigned to aquatic, vegetation, or soil groups based on their association with these microhabitats. To offset variability in arthropod life history patterns and species abundance within habitat types, arthropod categories based on presence/absence data over the six month period were constructed to provide for sampling reliability within each microhabitat …


Comparative Ecology And Conservation Status Of Procambarus (Pennides) Gibbus And Procambarus (Pennides) Versutus In Marion County, Georgia, Joann Chadwick Apr 2009

Comparative Ecology And Conservation Status Of Procambarus (Pennides) Gibbus And Procambarus (Pennides) Versutus In Marion County, Georgia, Joann Chadwick

Theses and Dissertations

Two crayfish species, whose conservation status was of concern, Procambarus (Pennides) gibbus Hobbs and Procambarus (Pennides) versutus Hagen, and one relatively common crayfish, Procambarus (Pennides) spiculifer LeConte were studied at nine creek sites in Marion County, Georgia. Major objectives of the yearlong study were to 1) compare the habitats of these species, looking for environmental differences that might account for their isolated distributions within the county and 2) assess the current conservation status of P. gibbus and P. versutus. Each study site was characterized by a one-time assessment of floodplain width, stream width, water velocity, stream depth and assessment of …


Forecasting Usaf Jp-8 Fuel Needs, Omer Saglam Mar 2009

Forecasting Usaf Jp-8 Fuel Needs, Omer Saglam

Theses and Dissertations

Oil is still one of the strategic energy resources for both the U.S. and the USAF today. Accurate oil prediction is important for the U.S. in order to improve the national strategy and the related budget concerns. Today, the U.S. is roughly importing 58% of its petroleum products. Moreover, in Fiscal Year (FY) 2007 the USAF total energy costs exceeded $6.9 billion. Aviation fuel accounted for approximately 81% of the total AF energy costs. Fluctuations in oil prices have huge impacts on the USAF’s JP-8 budgetary calculations. In order to handle this problem, the need for accurate forecasts arises. In …


The Economic Impact Of A Radiological Dispersal Device (Rde), Michael T. Lebrun Mar 2009

The Economic Impact Of A Radiological Dispersal Device (Rde), Michael T. Lebrun

Theses and Dissertations

While it will not cause the devastation of a nuclear weapon, the radiological dispersal event (RDE) is particularly dangerous in that it has the potential to cause major economic disruptions. The purpose of this research was to develop a generalized methodology that can be used to assess economic impacts, resulting from a (RDE), occurring in any location and across any industry. Currently, there is no universal approach for measuring the costs or economic impacts on businesses, or a common framework for conducting an economic impact for a RDE. The objective of this research was to aid in the RDE response …


An Evaluation Of Solar Air Heating At United States Air Force Installations, David S. Brown Mar 2009

An Evaluation Of Solar Air Heating At United States Air Force Installations, David S. Brown

Theses and Dissertations

The purpose of this research was to evaluate the use of solar air heating at U.S. Air Force installations. Specifically, this thesis analyzed Unglazed Transpired Collector (UTC) technology, more commonly known as SolarWalls®. This thesis sought to determine if UTC systems are an economically and environmentally viable technology which Air Force energy managers should include in their portfolio of alternative energy options. This research question was answered through the use of case studies and life-cycle cost analysis. Case studies were performed at various U.S. military installations which have already utilized UTC systems to provide a consolidated source of lessons learned. …


Modeling Of Aircraft Deicing Fluid Induced Biochemical Oxygen Demand In Subsurface-Flow Constructed Treatment Wetlands, William J. Mclaughlin Mar 2009

Modeling Of Aircraft Deicing Fluid Induced Biochemical Oxygen Demand In Subsurface-Flow Constructed Treatment Wetlands, William J. Mclaughlin

Theses and Dissertations

Aircraft deicing is vital to safe operation in cold weather environments. Unfortunately, release of glycol-based aircraft deicing fluids (ADF) to waterways adjacent to airfields poses a significant environmental threat. The deicing fluids used at DoD airfields impart a high biochemical oxygen demand (BOD) when they enter waterways. The currently accepted conventional treatment is collection and transport of ADF-laden storm water to a publicly owned treatment works. The volume and BOD concentrations in the storm water often make this type of treatment impractical. Subsurface flow constructed treatment wetlands have been demonstrated to be effective in attenuating ADF-induced BOD. The models currently …


Evaluation Of An Innovative Technology For Treatment Of Water Contaminated With Perchlorate And Organic Compunds, Maureen A. Downen Mar 2009

Evaluation Of An Innovative Technology For Treatment Of Water Contaminated With Perchlorate And Organic Compunds, Maureen A. Downen

Theses and Dissertations

Drinking water sources contaminated with both perchlorate and organic compounds have frequently been found in the U.S. Tailored granular activated carbon (T-GAC) is an innovative technology that is being evaluated to determine if it can more cost effectively remove perchlorate than conventional technologies. A question that has been raised is whether T-GAC can economically treat perchlorate-contaminated water that also has organic co-contaminants present. During a field study, trichloroethylene, an organic compound, and perchlorate were successfully removed by adsorption using a T-GAC/GAC system. These results motivated development of a model that could be applied to predict the cost and performance of …


Jet Fuel Hedging Strategies For The Department Of Defense Through Use Of Financial Derivatives, William T. Gibson Mar 2009

Jet Fuel Hedging Strategies For The Department Of Defense Through Use Of Financial Derivatives, William T. Gibson

Theses and Dissertations

The primary purpose of this research is to assess the practicality of utilizing some of the financial derivative products available on the market today in an effort to mitigate monetary losses due to the increasing price of jet fuel, thereby increasing stability in the DOD budget. The scope of this research will focus on the use of futures and call option contracts. Domestic jet fuel expenditure data was collected for Fiscal Years 1996 to 2007 and cross-referenced with the contract process of the previously mentioned financial hedging instruments during the same period of time. Results from the ex post facto …


Waste Vegetable Oil As An Alternative Fuel For Diesel Vehicles, Harvey S. Gaber Mar 2009

Waste Vegetable Oil As An Alternative Fuel For Diesel Vehicles, Harvey S. Gaber

Theses and Dissertations

Alternative fuels have become a hot topic in the news as the cost of oil remains volatile. Questions of whether acquiring alternative fuels are worth the cost, logistics, and political implications are being asked. A possible solution may be currently thrown away by Wright Patterson Air Force Base’s (WPAFB) dining establishments in the form of Waste Vegetable Oil (WVO). This study researched the benefits and costs of pursuing the installation of a WVO to Straight Vegetable Oil fuel processing center and using the fuel to power some of the base’s diesel vehicles. A pilot program was fielded utilizing the Wright …


A Metagenomic Analysis Of Microbial Contamination In Aviation Fuels, Jerrod P. Mccomb Mar 2009

A Metagenomic Analysis Of Microbial Contamination In Aviation Fuels, Jerrod P. Mccomb

Theses and Dissertations

Microbial contamination in aviation fuel arises due to the impracticality of keeping fuel tanks sterile and the inevitable presence of water from condensation. Microbial contaminants in aviation fuels are a concern because of their potential to degrade the fuel, accelerate corrosion within the fuel tank, and threaten flight safety. This research aids in mitigating those problems by comprehensively characterizing the microbial communities affecting aviation fuels. Advances in molecular biological techniques have allowed for the identification of microorganisms which were not identified by the traditional culture-based methodologies used in previous studies. This study employed a molecular method known as 16S rDNA …


Heterogeneity Effects In Plutonium Contaminated Soil, Orlando M. Chaparro Mar 2009

Heterogeneity Effects In Plutonium Contaminated Soil, Orlando M. Chaparro

Theses and Dissertations

In 1960 at the McGuire Air Force Base, New Egypt, New Jersey a helium tank ruptured causing a fire to ignite a nearby nuclear tipped Boeing Michigan Aeronautical Research Center (BOMARC) missile. During the fire the weapons grade plutonium (Pu- 239, Pu-240, and Pu-241) ignited and was released into the surrounding area, due to both firefighting efforts, where high pressure water was used to put out the fire, as well as smoke that deposited plutonium as oxidized particles in the surrounding area (Cicotte, 2007). This study investigates the heterogeneity of the distributed plutonium contamination in the McGuire Air Force Base …


Ohio River Denial As A Transportation Corridor And Its Economic Impacts On The Energy Industry, Caglar Utku Guler Mar 2009

Ohio River Denial As A Transportation Corridor And Its Economic Impacts On The Energy Industry, Caglar Utku Guler

Theses and Dissertations

What if the Ohio River is disrupted or denied partially or completely as a transportation corridor? A disruption may be either a natural or man-made disaster or a planned outage on the river’s lock and dam structures. Recent history is full of water transport disruption events having significant economic effects on the waterside industries. To assess coal-based economic impacts, we developed a network flow model to represent waterside coal-fired power plants situated along the Ohio River, their respective coal supplying mines, and the various transportation modes that connect them. We show that significant transportation-centric insights can be derived by using …