Engineering Commons^™

Anaerobic Treatment Of Army Ammunition Production Wastewater Containing Perchlorate And Rdx, Emina Atikovic, Makram T. Suidan, Stephen W. Maloney

United States Army: Publications

Perchlorate is an oxidizer that has been routinely used in solid rocket motors by the Department of Defense and National Aeronautics and Space Administration. Royal Demolition Explosive (RDX) is a major component of military high explosives and is used in a wide variety of munitions. Perchlorate bearing wastewater typically results from production of solid rocket motors, while RDX is transferred to Army industrial wastewaters during load, assemble and pack operations for new munitions, and hot water or steam washout for disposal and deactivation of old munitions (commonly referred to as demilitarization, or simply demil).
Biological degradation in Anaerobic Fluidized Bed …

Nebraska Summary: S648 Massey Ferguson 8650, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Catfish Consumption As A Contributor To Elevated Pcb Levels In A Non-Hispanic Black Subpopulation, Max Weintraub, Linda S. Birnbaum

United States Environmental Protection Agency: Publications

The human body burden of polychlorinated biphenyls (PCBs) sharply declined after production was banned in the US in 1979. For the 10% of the US population that remains most exposed to PCBs, fish consumption is the primary source. National Health and Nutrition Examination Survey (NHANES) data indicates that the highest remaining PCB levels exist in a non-Hispanic black subpopulation. Our review suggests that catfish consumption may be a significant PCB source for the one million non-Hispanic black anglers who fish for catfish. In comparison to non-Hispanic white anglers, non-Hispanic black anglers consume more catfish, are more likely to eat the …

The History Of The Unl Water Center From 1964, Water Center, School Of Natural Resources

Nebraska Water Center: Administrative Materials

Water is an integral part of Nebraska’s economy and well being in a state that depends on an adequate supply for all uses, including agricultural, municipal, industrial, recreational and wildlife habitat.

Nebraska is fortunate with regard to its water supply, having tremendous groundwater reserves which are estimated to be in excess of two billion acrefeet (an acre-foot being enough water to cover one acre of land with a foot of water, or approximately 325,000 gallons), combined with an estimated annual precipitation of 86 million acre-feet and annual average surface water inflows of 1.7 million acre-feet, give the state adequate supplies …

Computational Modeling Of Oxidative Stress: An Analysis Of Nad(P)H Effects On Nitric Oxide And Superoxide During Hypertension, Aaron Strobel

Inquiry: The University of Arkansas Undergraduate Research Journal

Nitric oxide (NO) is inactivated in the human body when exposed to superoxide (02-). This reaction forms peroxynitrite (ONOO). Superoxide is produced in the cardiac system by several mechanisms, including NAD(P)H oxidase. Superoxide dismutase (SOD) breaks down superoxide into oxygen and hydrogen peroxide. This prevents superoxide from reacting with nitric oxide and allows normal function to take place. Superoxide and peroxynitrite are main contributors to vascular disease in the human body, in particular hypertension.

Effects Of Gamma-Sterilization On The Physico-Chemical Properties Of Natural Sediments, T.L. Bank, Ravi K. Kukkadapu, A.S. Madden, M.A. Ginder-Vogel, M.E. Baldwin, P.M. Jardine

United States Department of Energy: Publications

Batch U(VI) sorption/reduction experiments were completed on sterilized and non-sterilized sediment samples to elucidate biological and geochemical reduction mechanisms. Results from X-ray absorption nearedge structure (XANES) spectroscopy revealed that γ-sterilized sediments were actually better sorbents of U(VI), despite the absence of any measurable biological activity. These results indicate that γ-irradiation induced significant physico-chemical changes in the sediment which is contrary to numerous other studies identifying γ-sterilization as an effective and minimally invasive technique. To identify the extent and method of alteration of the soil as a result of γ-sterilization, untreated soil samples, physically separated size fractions, …

Identifying And Explaining Map Quality Through Provenance: A User Study, Nicholas Ricky Del Rio, Paulo Pinheiro Da Silva

Departmental Technical Reports (CS)

Applications deployed on cyber-infrastructures often rely on multiple data sources and distributed compute resources to access, process, and derive results. When application results are maps, it is possible that non-intentional imperfections can get introduced into the map generation processes because of several reasons including the use of low quality datasets, use of data filtering techniques incompatible for the kind of map to be generated, or even the use of inappropriate mapping parameters, e.g., low-resolution gridding parameters. Without some means for accessing and visualizing the provenance associated with map generation processes, i.e., metadata about information sources and methods used to derive …

Equidecomposability (Scissors Congruence) Of Polyhedra In R^3 And R^4 Is Algorithmically Decidable: Hilbert's 3rd Problem Revisited, Vladik Kreinovich

Departmental Technical Reports (CS)

No abstract provided.

Enhanced Blocking Temperature And Isothermal Control Of Hysteresis Loop Shifts In Co/Nio/[Co/Pt] Heterostructures With Orthogonal Easy Axes, A. Baruth, Shireen Adenwalla

Nebraska Center for Materials and Nanoscience: Faculty Publications

Heterostructures of Co 4 nm/NiO 1.1 nm/[Co 0.4 nm/Pt 0.6 nm] with mutually orthogonal easy axes allow for isothermal tuning of the hysteresis loop shifts along the applied field axis at room temperature, as well as displaying a greatly enhanced blocking temperature. The loop shifts can be varied up to 35 Oe through the application of moderate dc magnetic fields of 3 kOe. The presence of the [Co/Pt] multilayer with perpendicular anisotropy is responsible for a significant enhancement of the blocking temperature. For this thickness of NiO, the blocking temperature is expected to be well below 50 K, in contrast …

A Low-Temperature Specific Heat Study Of Giant Dielectric Constant Materials, C. P. Sun, Jianjun Liu, J.-Y. Lin, Chun-Gang Duan, Wao-Ning Mei, H. D. Yang

Nebraska Center for Materials and Nanoscience: Faculty Publications

A low-temperature specific heat study has been performed on the insulating giant dielectric constant material CaCu₃Ti₄O₁₂ and two related compounds, Bi_2/3Cu₃Ti₄O₁₂ and La_0.5Na_0.5Cu₃Ti₄O₁₂, from 0.6 to 10 K. From analyzing the specific heat data in a very low-temperature range, 0.6–1.5 K, and moderately low-temperature range, 1.5–5 K, in addition to the expected Debye terms, we observed significant contributions originating from the linear and Einstein terms, which we attributed as the manifestation of low-lying elementary excitations due to lattice …

Self-Assembly Of A Micrometers-Long One-Dimensional Network Of Cemented Au Nanoparticles, Vivek C. Maheshwari, Jennifer Kane, Ravi F. Saraf

Ravi Saraf Publications

One-dimensional Au nanoparticles connected by ionic linkers self-assemble into a micrometer-scale network. Reactions between linker ions reinforce the assembly and lead to the formation of a continuous network. This continuous network demonstrates room temperature Coulomb-blockade characteristics that are indicative of electron transport along the 1D pathways.

Semi-Analytical Complex Variable Based Stochastic Finite Element Method, Weiya Jin

Mechanical and Aerospace Engineering Dissertations - Archive

The stochastic finite element method (SFEM) is an approach that allows an analyst to define material, load, and geometry parameters as random variables to represent uncertainty in an engineering problem. The method is then used to estimate the probability of exceeding specified performance thresholds. A necessary ingredient for this analysis is consistent, accurate and efficient algorithms for computing finite element response sensitivities. In this work, the semi-analytical complex variable method (SACVM) is introduced as a method for computing accurate response sensitivities of stochastic models. The SACVM incorporates the complex variable method (CVM) with the semi-analytical method (SAM). It takes advantage …

Corrosion Behavior Of Zn-Ni Coatings Deposited By Electrolytic Plasma Processing, Giancarlo Rios

Material Science and Engineering Theses - Archive

In the current research project, three groups of Zn-Ni coatings of various Ni contents were deposited on comercial carbon steel by electrolytic plasma processing (EPP), a novel surface modification technique. The coating characteristics were studied along with their corrosion behavior in order to determine their potential as electroplated Cd coating replacements. The latter electroplated coatings are currently used in aerospace applications but are toxic and hazardous to humans and the environment. Coating surfaces and cross sections were analyzed by scanning electron microscopy (SEM) while compositional analysis was conducted by energy-dispersive spectroscopy (EDS). Phase structure analysis was carried out by x-ray …

Fabrication And Characterization Of Cobalt-Diamond-Like-Carbon (Co-Dlc) Nanocomposites, Gunjan Shebe

Material Science and Engineering Theses - Archive

In recent years, synthesis of magnetic nanocomposites has been receiving significant attention. These nanocomposites offer opportunities to develop active nanomaterials with various applications like magnetic data storage and biomedical applications. They can be designed to provide excellent magnetic properties. However, high saturation magnetization materials, such as Co are not biocompatible. Thus, designing nanocomposites with magnetic phase embedded in biocompatible protective shells is of immense interest. In this study, Co-DLC nanocomposites were synthesized using a hybrid CVD/PVD technique and different combination of processing parameters were used to vary the concentration of Co in the nanocomposites. X-ray photoelectron spectroscopy showed, that with …

Effects Of Edge Distance, Hole Size Ratio And Hole Spacing On Peak Stresses Of Composite Laminate With Multiple Holes, Manishkumar Kheradiya

Mechanical and Aerospace Engineering Theses - Archive

Unlike isotropic material, the stress distribution of laminate with a hole varies with its size, its material properties and fiber orientations of each layer. Moreover, presence of a hole in the neighborhood of another hole may also affect their stress distribution, too. The major objective of this study is to determine stress distribution of finite width laminated composite having multiple holes. The effect of stress concentration due to presence of holes in each angle ply of laminated composite is a focus of this study. Three dimensional finite element models are developed to determine the stress distribution in laminate using commercial …

Characterization And Cooling Capacity Enhancement Of A Porous Ceramic Wick Based Coldplate, Mauricio Adrian Salinas

Mechanical and Aerospace Engineering Dissertations - Archive

Current passive cooling methods of aerospace and military, high heat-flux electronics include the use of thermal planes made of exotic metal alloys, which have been designed, at a great expense, to have high thermal conductivity and low density (i.e. light weight). Also, phase change modules composed of a metal matrix saturated with a solid phase change material are being employed for systems requiring a transient cooling scheme such as expendable weapons. This method requires the heat to be transferred from the source location, through the metal matrix (typically a porous aluminum foam), to the available phase change material. Preliminary empirical …

Thermal Design Optimization Of Internally Cooled Turbine Blades, James Daniel Ruiz

Mechanical and Aerospace Engineering Theses - Archive

This paper outlines the use of Computational Fluid Dynamics (CFD) and Genetic Algorithm (GA) Optimization to enhance the design of a 3-dimensional internally cooled turbine blade. The optimization code utilizes principles of Genetic Algorithms to optimize (i.e. minimize) the integrated heat flux through the turbine blade. The optimization is accomplished by adjusting the size and position (within pre-determined constraints) of cooling passages internal to the turbine blade. Starting with an aerodynamically optimized airfoil shape, cooling passage designs are generated by the optimization process and coupled with boundary and airfoil domains. The analysis becomes a Conjugate Heat Transfer (CHT) problem analyzing …

Development Of Spectral And Wavelet Time-Of-Flight Methods For Propagating Shock And Detonation Waves, Alfredo Albert Ortiz

Mechanical and Aerospace Engineering Theses - Archive

An accurate time delay estimate for a propagating disturbance, including an estimate of its uncertainty, is important in many areas of science. Several techniques were developed for determining the propagation time of a shock and detonation wave. The speed of the propagating wave was then determined by the time delay estimates provided for the best techniques. The techniques used ranged from the commonly used time-of-flight method to a nonstationary cross-spectral density phase method that provided a statistical estimation of the propagation time. The time delay results for a shock tube experiment showed that most of the methods had difficulties in …

Thermal Analysis Of Pulse Detonation Engines, Raghu Raman Ghandikota

Mechanical and Aerospace Engineering Theses - Archive

The pulse detonation engine (PDE) is a compact system that can be modeled thermodynamically by the Humphrey cycle and is capable of high efficiency. The rapid heat release for stochiometric fuel/oxidizer ratios results in developing high temperatures. The high temperatures produced during its operation can cause the engine to fail. Thus, operating this engine for a longer duration would become dubious if the temperatures are not dissipated from it. The current research aims to perform a preliminary thermal analysis. This analysis consists of two steps. The first step is to determine the heat dissipated from the engine using the unsteady …

Effect Of Pullout And Torsional Strength Of Composites With Co-Molded Thread Inserts, Dan L. Reller

Mechanical and Aerospace Engineering Theses - Archive

Rotorcraft transmission housings and drive system components are typically made from cast metals due to their highly complex geometries. Utilizing composite materials offers potential to reduce weigh and manufacturing cost while increasing corrosive resistance and extending part life. Traditional compression molded composites have not been utilized in aerospace because they typically experience low fiber volume fraction. Currently there are numerous materials which offer opportunities for composites in drive system housing applications and also offer the ability to co-mold details to reduce post mold operations. One of the issues associated with composite structures is the ability to fasten them to one …

Electromagnetic Flow Control: A Review And Experimental Development And Testing Of A Compact Actuator, Eric Braun

Mechanical and Aerospace Engineering Theses - Archive

This thesis is divided into two sections which both relate to the field of magnetohydrodynamics and particularly electromagnetic flow control (EMFC). The first section contains a review of recent research in EMFC. The second section presents the experimental results of a compact EMFC actuator designed for use at low speeds where the flow conductivity is raised by conductive seed particle injection.Fifty years ago, publications began to discuss the possibilities of using EMFC to improve aerodynamic performance. This led to an era of research that focused on coupling the fundamentals of magnetohydrodynamics (MHD) with propulsion, control, and power generation systems. Unfortunately, …

Finite Element Analysis Of Helicopter Main Rotor Hub Plates To Evaluate The Possibility Of Increasing The Time To Retirement, Douglas Wittig

Mechanical and Aerospace Engineering Theses - Archive

Rotorcraft main rotor systems have multiple components that are subject to very high loads and moments. These loads and moments dictate the life expectancy of the parts based upon the components material of composition. This project will primarily focus on the upper and lower hub plates on the main rotor system of a typical four bladed commercial helicopter. The upper and lower plates are machined from 7075-T73 aluminum forgings. The upper and lower plates were laboratory fatigue tested during product development as supporting parts in the test of the main rotor assembly. With recent advances in finite element analysis, there …

Fabrication And Characeterization Of Granular Magnetic Gold Nanoparticles, Rishi Wadhwa

Material Science and Engineering Theses - Archive

In recent years, gold and magnetic nanoparticles have showed great potential in biomedical applications. Magnetic nanoparticles can be used in both in- vivo and in-vitro applications such as drug and gene delivery, hyperthermia treatment of cancer, MRI contrast enhancement, cell labeling and magnetic separation. Due to the surface plasmon resonance effect (SPR), gold nanoparticles strongly absorb and scatter visible and infrared light in resonance with SPR. They have been exploited for bioimaging and photothermal therapy applications. This is why different sizes and shapes of Au nanoparticles exhibit different colors.In this thesis, we are investigating a new type of nanoparticles, granular …

Clay Mineralogy Effects On Long-Term Performance Of Chemically Treated Expansive Clays, Bhaskar Chandra Srinivas Chittoori

Civil Engineering Dissertations - Archive

Stabilization of expansive soils using chemical additives such as cement and lime had been in use for several decades and these treatments provide riding comforts to travelers. However, many state Departments of Transportation (DOTs) in the United States have had problems with subgrade failure even after stabilization with chemical additives due to a loss of stabilizer over time, or a stabilizer being ineffective in some soils while other soils with the same index properties respond well to that stabilizer. These problems are attributed to the limitations of the current procedures of stabilization for pavement subsoil layers. One such limitation is …

Construction Cost Of Underground Infrastructure, Seyed Behnam Hashemi

Civil Engineering Theses - Archive

Renewal of aging underground infrastructure is a major challenge that municipalities inNorth America face every day. Traditional replacement or renewal of these underground utilitiesuses open-cut excavation methods that can be disruptive to everyday life of citizens andexpensive, particularly in built-up areas and in projects with difficult ground and site conditions. Incontrast, trenchless technologies use innovative methods, materials, and equipment that requireminimum surface excavation to renew and construct aging underground infrastructure. Thesenew methods are considered to be more safe, cost-effective, efficient and productive thanconventional open-cut projects. However, to select trenchless technologies in utility design,consulting engineers and utility owners need to compare …

Adsorption Curve Fits For Landfill Vocs On Bituminous Coal Based And Coconut Shell Based Activated Carbon, Annaprabha Athappan

Civil Engineering Theses - Archive

This study explores adsorption as a method of controlling hazardous gas emissions from Municipal Solid Waste Landfills (MSWL). In particular, the hazardous air pollutants (HAPs) para, meta, and ortho-xylene, ethylbenzene and methyl ethyl ketone are selected for experimental study. Activated carbon is a good adsorbent and well known for its high surface area. Among the many varieties of activated carbon, bituminous coal based activated carbon (BPL) and coconut shell based activated carbon (OVC) are compared in this study. Each experiment was conducted in a vial with a known amount of carbon in it. The pollutant concentration remaining in the vial …

Optimization Of Reconstruction Parameters In Brain Activation Studies, Aswini Kanneganti

Bioengineering Theses - Archive

Diffuse Optical Imaging (DOI) is being extensively used in brain activation studies for the quantification of hemodynamic changes in the cerebral cortex. Many investigators have utilized the commercially available CW5 DOI device to attain cortical activation maps. However, the localization and spatial resolution in the resulting activation images remains poor. These limitations arise due to the large source detector separations required for light to reach the brain's surface and the limited number of detector channels in the CW5 system, which result in sparse spatial sampling of the cortical activation regions. In this thesis we assess the feasibility of using denser …

Assessing Control Strategies For Ground Level Ozone, Neelesh Vijay Sule

Civil Engineering Dissertations - Archive

Developing cost effective control strategies for ozone has been a challenge to air quality modelers. Conventionally, the control strategies are applied across-the board to the region. The main aim of this research was to develop a Decision-Making Framework (DMF) for evaluating and optimizing the selection of ozone control strategies. Conventional across-the-board reductions conduct emission reductions uniformly throughout the region and throughout the day. By contrast, this dissertation studied targeted reductions, in which emission sources of various types are reduced at various times and locations. The proposed DMF comprised of four phases: (1) Initialization, (2) Mining, (3) Metamodeling, and (4) Optimization. …

Measured And Theoretical Response Of Perpetual Pavement Structures, Miguel M. Portillo

Civil Engineering Theses - Archive

The Kansas Perpetual Pavement experiment includes the construction of four pavement sections on the US-75 highway designed according to the perpetual pavement concept. The sections were instrumented with strain gauges and pressures cells to measure strains and stress at the bottom of the base layer and at the top of the subbase layer. Pavement response measurements were carried out in seven occasions between July 2005 and October 2007 with a loaded truck. Measured values obtained show that longitudinal and transverse values were almost always below the average endurance limit of 70 microstrains. The measurements also showed that temperature and vehicle …

Fano Resonance Filters On Patterned Silicon Photonic Crystal Nanomembranes, Santhad Chuwongin

Electrical Engineering Theses - Archive

Recently broadband reflectors and guided-resonance narrowband filters have been proposed to be the major components in communication and optical interconnect systems. Most work reported so far are based on free-standing membranes. Recent advances in the fabrication process have made it possible to pattern crystalline silicon nanomembranes (NMs) and transfer to foreign substrates. These NMs are transferable, stackable, bondable and manufacturable. In this thesis, we present two-dimensional photonic crystal broadband reflectors and narrowband filters based on Fano resonances on patterned silicon nanomembranes, on Si, glass, and polyethylene terephthalate (PET) substrates. For broadband reflectors, spectral trimming was achieved by partially or even …