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Full-Text Articles in Engineering
Development Of Peptide Nanotube-Modified Biosensors For Gas-Phase Organophosphate Detection, Peter A . Baker
Development Of Peptide Nanotube-Modified Biosensors For Gas-Phase Organophosphate Detection, Peter A . Baker
Theses and Dissertations
Vapor-phase detection of the model organophosphate malathion was achieved using enzymes encapsulated in peptide nanotubes and attached to gold screen-printed electrodes. Malathion was chosen as the model for this experiment because its binding mechanism with acetylcholinesterase (AChE) is identical to its more potent counterparts (such as sarin or VX), but it has an extremely low human toxicity, which makes it both practical and easy to use. The peptide nanotubes had horseradish peroxidase encapsulated inside and were coated with both acetylthiocholine (ASCh) and AChE on the outside. ASCh hydrolysis, which produces thiocholine, was catalyzed by the AChE. The thiocholine was then …
Understanding The Effects Of Climate On Airfield Pavement Deterioration Rates, Justin C. Meihaus
Understanding The Effects Of Climate On Airfield Pavement Deterioration Rates, Justin C. Meihaus
Theses and Dissertations
Over the past two decades, pavement engineers at the Air Force Civil Engineer Center have noticed the majority of identified distresses from PCI airfield surveys are climate related. To verify these trends, a comprehensive analysis of the current airfield pavement distress database was accomplished based on a climate region perspective. A four-zone regional climatic model was created for the United States using geospatial interpolation techniques and climate data acquired from WeatherBank Inc. Once the climatic regional model was developed, the climate information for each installation was imported into the Air Force pavement distress database within PAVER. Utilizing the pavement condition …
Case Study Analysis Of Trust And Commitment Between The Civil Engineering Commodity Council And The Civil Engineering Career Field, Jonnathan B. Page
Case Study Analysis Of Trust And Commitment Between The Civil Engineering Commodity Council And The Civil Engineering Career Field, Jonnathan B. Page
Theses and Dissertations
The Air Force is pursuing strategic sourcing as a strategy for reducing costs of goods and services to help meet budget reductions while still performing its mission. These commodities are sourced through a number of commodity councils, each of which whom interact with their stakeholders throughout the sourcing process for that specific commodity. This research identifies factors that influence the success or failure of the sourcing process from the perspective of the Civil Engineering Commodity Council (CECC) and attempts to organize these factors within a framework built around trust and its effect on commitment and cooperation. These factors were identified …
An Analysis Of Cost Premiums And Losses Associated With Usaf Military Construction (Milcon), Daniel L. Blomberg
An Analysis Of Cost Premiums And Losses Associated With Usaf Military Construction (Milcon), Daniel L. Blomberg
Theses and Dissertations
Military construction (MILCON) represents 40% of the federal government's $30 billion construction budget. The federal budget is fixed; therefore, any cost overages likely affect project scope or requirements. This study investigated if MILCON procurement costs more than private industry construction and if so, what causes the cost premiums. A combination of in-depth literature review, expert interviews, a unique case study, expert surveys, and geospatial statistical analysis answered the research question. The case study evaluated two nearly identical projects to determine how internal factors affect MILCON cost premiums. This study confirmed the existence of MILCON cost premiums. Additionally, 11 major cost …
Successfully Implementing Net-Zero Engergy Policy Through The Air Force Military Construction Program, D. Gavin Brost
Successfully Implementing Net-Zero Engergy Policy Through The Air Force Military Construction Program, D. Gavin Brost
Theses and Dissertations
The U.S. Government has issued numerous policies aimed at reducing federal facility energy consumption; the most recent, Executive Order 13514, requires that new construction designed after 2020 can achieve net-zero energy by 2030. The policy defines a Zero-Energy Building as one that is designed, constructed, and operated to reduce energy demand to a level which can be offset from sources of renewable energy. This research develops and evaluates a feasibility assessment model based on life-cycle cost. It incorporates geospatial analysis to calculate and summarize input values for all Air Force installations in the Contiguous U.S. A comparative analysis is then …
An Analysis Of Factors That Influence The Success Of Expeditionary Civil Engineer Hub-And-Spoke Organizations, Joshua A . Hager
An Analysis Of Factors That Influence The Success Of Expeditionary Civil Engineer Hub-And-Spoke Organizations, Joshua A . Hager
Theses and Dissertations
Expeditionary Air Force Civil Engineer support to recent operations in southwest Asia created a unique organizational learning environment, particularly related supporting the general engineering requirements of geographically separated units in a manpower-constrained contingency environment. One of the direct results of this organizational learning was the hub-and-spoke expeditionary engineer unit featuring elements of both RED HORSE and Prime BEEF capabilities operating with theater-wide visibility of infrastructure requirements. This study acquired insights from literature and a purposeful sample of subject matter experts about operational advantages this hub-and-spoke unit offered compared to those offered by strictly legacy organizational models. The research used a …
Biodegradation Of An Organophosphate Chemical Warfare Agent Simulant By Activated Sludge With Varying Solid Retention Times, Allen K. Janeczko
Biodegradation Of An Organophosphate Chemical Warfare Agent Simulant By Activated Sludge With Varying Solid Retention Times, Allen K. Janeczko
Theses and Dissertations
This study examined the fate of malathion, a surrogate compound for VX studies, in bench-scale sequencing batch bioreactors being operated under varied solid retention times (SRTs) to simulate the activated sludge process in wastewater treatment facilities. Results show that a constant influent of the malathion will largely be removed. However, the heterotrophic bacteria undergo a stress response which temporarily inhibits malathion removal, the extent of which increases with increasing SRTs. After this stress response takes place, the activated sludge is able to resume a high degree of malathion removal, even with increased influent concentration; however, this is done so at …
Influence Of Media Size And Flow Rate On The Transport Of Silver Nanoparticles In Saturated Porous Media: Laboratory Experiments And Modeling, Travis J. Meidinger
Influence Of Media Size And Flow Rate On The Transport Of Silver Nanoparticles In Saturated Porous Media: Laboratory Experiments And Modeling, Travis J. Meidinger
Theses and Dissertations
Silver nanoparticles (AgNPs) are widely produced and used. Because of their potential toxicity and the possibility of their release into the environment, it is important to understand the factors involved in their transport; particularly how they may move in groundwater, which is a potential pathway to human and environmental receptors. By passing a solution of 15 mg/L AgNPs with an average size of 17 nm through sand-filled glass columns, this study looks at the physical effects of flow rate and media size on transport. Three different sand sizes ( 0.074, 0.21-0.297, and 0.4-2.0mm) were used, as well as two different …
Assessment Of Potential Carbon Dioxide-Based Demand Control Ventilation System Performance In Single Zone Systems, Joseph G. Pickenpaugh
Assessment Of Potential Carbon Dioxide-Based Demand Control Ventilation System Performance In Single Zone Systems, Joseph G. Pickenpaugh
Theses and Dissertations
Heating, ventilation, and air conditioning (HVAC) use accounts for 43% of commercial energy consumption, with close to 5% used for ventilation purposes. Federal government agencies face both energy consumption reduction mandates and reduced funding. Carbon dioxide (CO2) based demand control ventilation (DCV) is a technology that allows for reduced energy consumption by allowing facility designers to introduce outside air based on facility occupancy, per American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) standards. This research aims to create a generalized methodology assessing energy and cost reductions from CO2-based DCV and then apply it to a specific facility at …
Fate Of Malathion In An Activated Sludge Municipal Wastewater Treatment System, Edward B. Walters
Fate Of Malathion In An Activated Sludge Municipal Wastewater Treatment System, Edward B. Walters
Theses and Dissertations
Organophosphate compounds are used as pesticides and in chemical warfare agents such as nerve agents. VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate) is one of the most toxic and environmentally persistent of these nerve agents. This research examined the fate of malathion, a pesticide and surrogate of VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate), in bench-scale activated sludge (AS) sequencing batch reactors. Sorption kinetics and sorption equilibrium isotherm experiments indicate that sorption to AS biomass was not a statistically important removal mechanism. However, approximately 90% of the initial 4.25 mg L-1 malathion concentration degraded primarily via heterotrophic activity.