Digital Commons Network^™

Simulating Wet Deposition Of Radiocesium From The Chernobyl Accident, Aaron M. Kinser

Theses and Dissertations

In response to the Chernobyl nuclear power plant accident of 1986, a cesium-137 deposition dataset was assembled. Most of the airborne Chernobyl cesium was wet deposited, either via interception by falling raindrops or via absorption into cloud droplets destined to become raindrops. The Hybrid Single-Particle Lagrangian rated Transport (HYSPLIT) model, developed at Air Resources Laboratory, is used to simulate the transport and deposition of Chernobyl cesium-137. A cloud base parameterization modification is tested and appears to slightly improve the accuracy of one HYSPLIT simulation of daily Chernobyl cesium-137 deposition over the course of the accident at isolated European sites, and …

Modeling Biodegradation Of Chlorinated Groundwater Contaminants Under Iron-Reducing Conditions Of A Constructed Wetland: A System Dynamics Approach, Max E. Johnson

Theses and Dissertations

The purpose of this study is to determine and explore the fundamental processes associated with biodegradation of chlorinated ethenes in iron-reducing conditions of a constructed wetland and to evaluate the impacts of changing conditions (both natural and engineer-controlled) on the system. The modeler uses a system dynamics approach to construct a model that represents behavior in the iron-reducing environment. The model incorporates hematite, a form of oxidized iron (Fe³⁺), as the electron acceptor in microbial biodegradation in the system. Vinyl chloride, cis-dichloroethene, and trans-dichloroethene are known to anaerobically degrade to carbon dioxide in the presence of oxidized iron. …

Malicious Hackers: A Framework For Analysis And Case Study, Laura J. Kleen

Theses and Dissertations

Recent years have seen an increase in the number and severity of Information Operations (IO) attacks upon DoD resources. At a higher level, the US as a whole has come under cyber attack by individuals and groups seeking thrills, monetary gain, publicity for their causes, and myriad other goals. This effort develops a first cut model of individual hacker mentality that can be utilized to improve threat assessment, mitigate Information Assurance (IA) vulnerabilities, and improve risk assessment. Further, it is a first step toward automated characterization of Information Warfare (IW) attacks based upon hacker types. All hackers are not the …

Air Vehicle Optimal Trajectories For Radar Exposure Minimization, Michael C. Novy

Theses and Dissertations

This study addresses the problem of analyzing the single vehicle path planning problem for radar exposure minimization. The calculus of Variations and optimal control are applied to formulate the cost function and numerical algorithms are used to solve for the optimal paths. Cost sensitivity to path length is analyzed for flight against one radar; a second radar is then included in the formulation and the optimal path for flight between the radars is found for cases of equal and unequal radar power. The costs of the optimal path, direct path, and Voronoi diagram-generated paths are compared. Results indicate low sensitivity …

Estimating C-17 Operating And Support Costs: Development Of A System Dynamics Model, Christopher D. Purvis

Theses and Dissertations

This research provides justification for experimenting with system dynamics (SD) for performing Operation and Support Cost estimates. For the C-17 Globemaster III cargo aircraft, these costs could exceed $64 billion dollars. Also, many of our weapon systems are beginning to reach the end of their effective life span, and discussions about the impact of aging, on aircraft, has become a hot topic in the literature. System Dynamics is a modeling methodology developed in 1958, but never used extensively for cost estimating. SD offers unique capabilities to the cost estimator, including the ability to model causal relationships. This capability offers the …

Determining The Value Of Groundwater Contamination Source Removal: A Methodology, Benjamin C. Recker

Theses and Dissertations

Subsurface contamination by industrial chemicals is one of the most prevalent and costly environmental problems facing the United States government. This contamination problem must be managed to protect human health and the environment. Two basic strategies are used to deal with subsurface contamination: source removal and contaminant containment. While much cost and performance data are available for individual technologies associated with each of these strategies, there have been very few studies that have examined the benefits of implementing source removal technologies in order to reduce contaminant containment (and hopefully total) costs. This study examines the tradeoff between extent of source …

A Model For Palladium Catalyzed Destruction Of Chlorinated Ethenes In Contaminated Groundwater, Christopher M. Stoppel

Theses and Dissertations

Groundwater contamination by chlorinated ethenes is a widespread environmental problem. Conventional remediation technologies have shortcomings that have prompted further research into the development of novel treatment technologies. A palladium/ alumina catalyst in the presence of dissolved molecular hydrogen (referred to hereafter as a PD/H₂ system) has been demonstrated to rapidly destroy chlorinated ethene contaminated groundwater. First-order kinetics have been used to model chlorinated ethene destruction in a PD/H₂ reactor. However, catalyst deactivation and regeneration are important processes that also need to be modeled in order to better understand their effect on treatment efficiency. This study presents a model …

Decision Analysis Methodology To Evaluate Integrated Solid Waste Management Alternatives For A Remote Alaskan Air Station, Mark J. Shoviak

Theses and Dissertations

Eareckson Air Station (AS), a remote U.S. Air Force installation, faces the complex decision of selecting a new municipal solid waste (MSW) management strategy to replace its current non-compliant system. This research effort applies value-focused thinking and multiattribute preference theory to decision analysis techniques to produce a multiple-objective decision analysis model that captures all of the site's MSW goals, objectives, and concerns in order to facilitate the evaluation of MSW management strategies available. The model ranks 40 specific MSW management alternatives, which were developed in accordance with the decision-maker's assumptions and constraints, based on how well they meet Eareckson's overall …

An Analysis Of Civil Engineer Officer Contingency Training, Rusty J. Vaira

Theses and Dissertations

The primary objective of this research was to investigate the current overall civil engineer officer contingency training program and determine if civil engineer officers think it is adequately preparing them to perform in a contingency environment. In accomplishing this objective, this research explored the perceptions that officers have about the contingency training that is available through three primary training programs (Home Station Training, Silver Flag training, and Civil Engineer and Services School training). The overall intent of the author was to gauge how the officers feel about their contingency training and offer some suggestions on how to improve the training. …

Quantitative Validation Of A Model Of Chlorinated Ethene Natural Attenuation, Harold C. Young

Theses and Dissertations

Chlorinated ethenes are among the most prevalent groundwater contaminants at hazardous waste sites nationwide. In an attempt to manage the risks posed by these contaminants, while controlling costs, monitored natural attenuation (MNA) is being considered as a remediation strategy at many sites. MNA relies on naturally occurring physical, chemical, and biological processes in the subsurface to reduce the risk posed by the contamination. The implementation of MNA, however, requires a detailed understanding of these processes, and how they impact contamination at a particular site. One way to gain this understanding is through contaminant fate and transport modeling. In this study, …

Surface-Enhanced Raman Spectroscopy Of Metallotetraphenyl Porphyrins Adsorbed On Ag2O And Silver Colloids, Ying-Hui Zhang, Dong-Ming Chen, Tian-Jing He, Fan-Chen Liu

Journal of Electrochemistry

The biological significance of porphyrins and metalloporphyrins has stimulated intensive investigations on these compounds for many years. On the other hand, porphyrins and metalloporphyrins also have extensive applications in many other fields such as chemical modified electrodes, organic photovoltaic devices and biomimetic catalysis. The adsorption behavior and chemical reactions of metalloporphyrins on surfaces or interfaces are very important for these applications.

Raman Spectroelectrochemical Study On Bioactive Molecules, Xiao-Wei Cao, Hai-Feng Yang, Zhe Su Meng Xiao Yun Wang, Xia-Qin Wu, Zong-Rang Zhang

Journal of Electrochemistry

Electron-transfer reaction is known to be one of the key reactions for generating biological functions. Mechanism revelation at a molecular level of such kind reactions is to be very helpful for us to understand life essence. In fact, surface enhanced Raman scattering (SERS) is one of the most powerful tools for the study on metal-electrolyte and metal-vacuum interfaces since 1970's. Moreover, Raman spectroscopic study in enzymology has provided attractive results during last twenty-five years.

Michaelis–Menten Kinetics For Enzymatic Depolymerization Of A Linear Polyester Synthesized From Z-Protected Glutamic Acid, R. M. Tadros, Hossein Noureddini, Delmar C. Timm

Papers in Biomaterials

A biodegradable polyester resin was polymerized from N-benzyloxycarbonyl-L-glutamic acid and ethylene glycol. Rhizopus delemar lipase was used as a biocatalyst for the rupture of ester bonds during the hydrolysis studies. Depoly-merization was observed to followa Michaelis–Menten mechanism, with the maximumrate of monomer formation dP/dt_max = 1.12 x 10^-8 mol/s and the rate constant K_m x 2.03 x 10^-4 mol. Subject to initial conditions described by the most probable distribution and Michaelis–Menten–type depolymerization rate expressions, population density distribution dynamics of the polymeric molecules that formed the resin were explicitly described using a deterministic approach.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 17, Number 5, February 2001, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Numerical Modeling And Optimization Of Waterjet Based Surface Decontamination, Konstantin Babets

Dissertations

The mission of this study is to investigate the high-pressure waterjet based surface decontamination. Our specific objective is to develop a practical procedure for selection of process conditions at given constraints and available knowledge. This investigation is expected to improve information processing in the course of material decontamination and assist in the implementation of the waterjet decontamination technology into practice. The development of a realistic procedure for processing of a chaotic and non-accurate information constitutes the main accomplishment of this study.

The research involved acquisition of representative information about removal of brittle, elastic and viscous deposits. As a result an …

Development And Application Of A Computer Simulation Tool For Ecological Risk Assessments, Haiyi Lu

Theses

In an effort to improve tools in ecological risk assessment (ERA), an ERA software tool was developed and applied. Based on a preliminary evaluation of existing ecorisk models, the relative deficiencies were identified and included the need for a user-friendly interface, an interactive database management system (DBMS), and a comprehensive evaluation of exposure pathways. In this research, Visual Basic (VB) 6.0 and Microsoft SQL server were selected for developing the Windows-based interface and local DBMS, respectively. For the exposure estimate, Yuma and Aberdeen Proving Grounds were identified as baseline ecosystems. Terrestrial and aquatic plant and animal receptor selection was based …

Optimization Of Nitrogen Removal In Sequencing Batch Reactor, Suppakit Poonyachat

Theses

Operating parameters for sequencing batch reactor have the influenceon each substrate concentration. Concentration profile changes as operationparameters are changed. The study was conducted to model the variationin effluent concentration from sequencing batch reactor. MLVSS and cycletime are the parameters that were varied. Concentration in Fill, React,and Settle Period were calculated by using kinetic equations.

The results can show that these parameters have effects on the concentrationprofile. The increase of MLVSS can lower the concentration of BOD andammonium concentration in React period. Increasing MLVSS can show thatmore substrate utilization and nitrification process occur more rapidly.Concentration of nitrate at the end of …

Testing Of Semiconductor-Based Adsorption Modified Photosensitive (Samp) Sensor For Response To Toluene, Ashish Agrawal

Theses

The response of semiconductor-based adsorption modified photosensitive sensor is based on the dye-enhanced photoconductivity of a CdS semiconducting film. The change in this photoconductivity is brought about when organic molecules are sorbed onto the dye-coated surface. The response is related to the overlap in the infrared spectrum of the dye with that of the analyte.

This research was carried out to study the response of the sensor to a typical hydrocarbon, toluene. The sensor was tested for its response to concentrations of toluene ranging from 2.6 ppm to 200 PPM in nitrogen. The sensor was tested under non-flow conditions and …

Manure Impacts On Interrill Erosion, John E. Gilley, Bahman Eghball, J. M. Blumenthal, David D. Baltensperger

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

This study was conducted to measure runoff and erosion from interrill areas as affected by the long-term application of manure and fertilizer to a Tripp sandy loam soil located near Mitchell, Nebraska. Soil that had been removed from the top 0.1 m of the soil profile was placed in a 1 m² soil pan. Rainfall was then applied to the soil pan during initial and wet simulation events. Total runoff was similar on the manure and no-manure treatments. The long-term application of manure (55 years) at a rate of 27 Mg ha^-1 (wet basis) per year did not …

A Site Specific Impact Study: Valley Fill Construction Impacts On Water Chemistry And Benthic Macroinvertebrate Assemblages, Terry Morton Tomasek

Theses, Dissertations and Capstones

Downstream impacts of contour surface mining and valley fill construction were evaluated utilizing both water chemistry and EPA approved Rapid Bioassessment Protocol III. Wiley Branch was sampled in February of 1999 before mining perturbation. Five downstream stations were established with benthic macroinvertebrates and water samples collected seasonally for a period of sixteen months. Water chemistry parameters, pH, total aluminum, iron, and manganese, total suspended solids, total dissolved solids, sulfates, alkalinity, acidity and specific conductivity fluctuated but generally remained within acceptable governmental limits. Initially, benthic macroinvertebrate communities were well balanced within the stream. There was a high abundance of EPT individuals …

The Prospect For Answer Sets Computation By A Genetic Model, A. Bertoni, G. Grossi, A. Provetti, Vladik Kreinovich, L. Tari

Departmental Technical Reports (CS)

We combine recent results from both Logic Programming and Genetic Algorithms to design a new method for the efficent computation of Answer Sets of logic programs. First of all the problem is reduced to the problem of finding a suitable coloring on directed graphs. Then the problem of finding a suitable coloring is relaxed to a combinatorial optimization problem and solved (in an approximate way) by a continuous discrete time system derived by a genetic model.

Enhanced Biodegradation Of Hydrocarbon Contaminants Using Photocatalytic Pretreatment, Chad E. Green, Anita Stansberry, Jeff Sczechowski, Yarrow Nelson

Civil and Environmental Engineering

Photocatalysis was investigated as a pretreatment for hydrocarbon groundwater contamination at an abandoned oil field in Guadalupe, CA. A laboratory photoreactor, with a UV fluorescent lamp submerged in a suspension of TiO₂ catalyst particles, was used to determine oxidation rates and the increase in biodegradability of the hydrocarbon mixture. Chemical oxidation demand (COD) and 5-day biological oxygen demand (BOD₅) were measured as a function of exposure time using standard methods. During eight-hour photoreactor runs in a nitrogen atmosphere, the COD of diluent solutions in de-ionized water and diluent solutions in simulated groundwater both decreased by approximately 50%, …

Basic Engineering Science --- A Systems, Accounting, And Modeling Approach, Donald E. Richards

Faculty Publications - Mechanical Engineering

This textbook is based on a different paradigm for organizing an engineering science core --- a systems, accounting and modeling approach --- that emphasizes the common, underlying concepts of engineering science. Although this approach is not new, as most graduate students have been struck by this idea sometime during their graduate education, its use as the organizing principle for an undergraduate curriculum is new. By focusing on the underlying concepts and stressing the similarities between subjects that are often perceived by students (and taught by faculty) as unconnected topics, this approach provides engineering students a foundational framework for recognizing and …

Composites In Construction: Present Situation And Priorities For Future Research, Antonio Nanni, Edoardo Cosenza, Gaetano Manfredi, Andrea Prota

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper was written at the conclusion of the International Workshop titled "Composites for Construction: A Reality," held in Capri, Italy, July 20-21, 2001. Its objective is to collect and summarize main ideas, opinions, evaluations, and proposals that emerged during the discussions held by the participants at break-up and general sessions. For simplicity, the reporting follows the order of such sessions and includes elements from the general sessions when applicable. The paper is intended to help professionals and scientists interested in the study and implementation of composites for the built infrastructure by providing a vivid snapshot of the state-of-the-art situation, …

Manipulating Dna Conformation Using Intertwined Conducting Polymer Chains, Ramaswamy Nagarajan, Wei Liu, Jayant Kumar, Sukant K. Tripathy, Ferdinando F. Bruno, Lynne A. Samuelson

United States Army: Publications

In the field of inherently conducting polymers, polyaniline (Pani) has elicited tremendous interest due to its promising electrical properties and unique redox tunability. Synthetic routes involving the use of polyelectrolytes have significantly improved the processability of polyaniline. Recently, a template guided synthesis catalyzed by an enzyme, horseradish peroxidase (HRP), has provided a means of polymerizing aniline under milder pH conditions (pH 4.3) and subsequently widened the choice of templates to more delicate biological macromolecules. Here we report a strategy that exploits the inherent molecular order as well as the polyelectrolyte behavior of DNA to enzymatically synthesize and biologically assemble conducting …

Lab Fattening And Non-Invasive Estimates Of Body Composition In Deer Mice, Edward T. Unangst, Michael J. Blair, Matthew W. Granger, David W. Hale

United States Air Force: Publications

Total body electrical conductivity measurements and lipid composition were determined for the deer mouse (Peromyscus maniculatus) to derive species specific calibration equations for use with EM-SCAN estimates of lean and fat tissue. For each individual, total body electrical conductivity was measured by EM-SCAN, and actual lipid content was determined by chemical extraction. Then, using estimated and actual lipid values, separate calibration equations were generated for freshly captured (lean) and laboratory maintained (fat) individuals, and a combined equation was derived for all individuals. These equations were variable in the accuracy of lipid estimates; the lowest relative error estimate (percent …

Biotransformation Of Ni-Substituted Hydrous Ferric Oxide By An Fe(Iii)-Reducing Bacterium, James K. Fredrickson, John M. Zachara, Ravi K. Kukkadapu, Yuri A. Gorby, Steven C. Smith, Christopher F. Brown

United States Department of Energy: Publications

The reductive biotransformation of a Ni²⁺-substituted (5 mol %) hydrous ferric oxide (NiHFO) by Shewanella putrefaciens, strain CN32, was investigated under anoxic conditions at circumneutral pH. Our objectives were to define the influence of Ni²⁺ substitution on the bioreducibility of the HFO and the biomineralization products formed and to identify biogeochemical factors controlling the phase distribution of Ni²⁺ during bioreduction. Incubations with CN32 and NiHFO were sampled after 14 and 32 d, and both aqueous chemistry and solid phases were characterized. By comparison of these results with a previous study (Fredrickson, J. K.; Zachara, J. M.; …

Dissimilatory Bacterial Reduction Of Al-Substituted Goethite In Subsurface Sediments, Ravi K. Kukkadapu, John M. Zachara, Steven C. Smith, James K. Fredrickson, Chongxuan Liu

United States Department of Energy: Publications

The microbiologic reduction of a 0.2 to 2.0 µm size fraction of an Atlantic coastal plain sediment (Eatontown) was investigated using a dissimilatory Fe(III)-reducing bacterium (Shewanella putrefaciens, strain CN32) to evaluate mineralogic controls on the rate and extent of Fe(III) reduction and the resulting distribution of biogenic Fe(II). Mössbauer spectroscopy and X-ray diffraction (XRD) were used to show that the sedimentary Fe (III) oxide was Al-substituted goethite (13–17% Al) that existed as 1- to 5-µm aggregates of indistinct morphology. Bioreduction experiments were performed in two buffers [HCO₃^‑; 1,4-piperazinediethansulfonic acid (PIPES)] both without and with 2,6-anthraquinone …

Kinetics And Mechanism Of Birnessite Reduction By Catechol, Christopher J. Matocha, Donald L. Sparks, James E. Amonette, Ravi K. Kukkadapu

United States Department of Energy: Publications

The complex interactions of oxidizable organic ligands with soil Mn(III,IV) (hydr)oxide minerals have received little study by in situspectroscopic techniques.We used a combination of an in situ electron paramagnetic resonance stopped-flow (EPR-SF) spectroscopic technique and stirred-batch studies to measure the reductive dissolution kinetics of birnessite (δ-MnO₂), a common Mn mineral in soils, by catechol (1,2-dihydroxybenzene). The reaction was rapid, independent of pH, and essentially complete within seconds under conditions of excess catechol at pH 4 to 6. The overall empirical second-order rate equation describing the reductive dissolution rate was d[Mn(II)]/dt = k[CAT]^1.0[SA]^1.0 where …

Kinetic Analysis Of The Bacterial Reduction Of Goethite, Chongxuan Liu, John M. Zachara, James K. Fredrickson, Cynthia Brinkman

United States Department of Energy: Publications

The kinetics of dissimilatory reduction of goethite (RFeOOH) was studied in batch cultures of a groundwater bacterium, Shewanella putrefaciens, strain CN32 in pH 7 bicarbonate buffer. The rate and extent of goethite reduction were measured as a function of electron acceptor (goethite) and donor (lactate) concentrations. Increasing goethite concentrations increased both the rate and extent of Fe(III) reduction when cell and lactate concentrations were held constant. However, constant initial reduction rates were observed after normalization to the Fe(II) sorption capacity of FeOOH, suggesting that the bacterial reduction rate was first order with respect to surface site concentration. Increasing …