Engineering Commons^™

Conversion Of Biomass Resource To Useful Forms Of Energy And Other Products, Latosha Johnson

Chemical Engineering Undergraduate Honors Theses

The United States is facing increasing pressure to find renewable energy sources due to rising energy costs. With world energy demand at an all time high, renewable energy has been thrust into the forefront of research as a means to mitigate this looming crisis. Throughout the United States, there is a large quantity of agricultural biomass that could be used to generate energy and lessen the dependence on diminishing resources. Specifically, animal feeding operations (AFOs) such as dairies generate large amounts of cow manure, which, when improperly handled, causes both air and water pollution. Currently, most manure is temporarily stockpiled …

Diffusion-Free Back Contact Solar Cells On S-Passivated Si(100) Substrates, Guanghua Song

Material Science and Engineering Dissertations - Archive

A diffusion-free back contact solar cell is proposed in this work. The textured front-side of this cell is coated with ~100 nm thermal SiO2 to enhance the light trapping meanwhile reduce the surface recombination velocity (SRV). The back-side of this cell is finger-patterned, using a diffusion-free junction as its emitter region and Al-Si alloy as its base contact. The diffusion-free junction is made by a Schottky contact between low work-function metal aluminum (Al) and sulfur (S)-passivated p-type Si(100) surface. Solution-based S passivation is one of the experimental realizations of the "valence-mending concept". Previously developed MBE (molecular bean epitaxy) selenium (Se) …

Phase Iii Development Of A Short-Radius Guardrail For Intersecting Roadways, Cody S. Stolle, Karla A. Polivka, Robert W. Bielenberg, Ronald K. Faller, Dean L. Sicking, John R. Rohde, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Development Of A Tl-5 Vertical Faced Concrete Median Barrier Incorporating Head Ejection Criteria, Scott Rosenbaugh, Dean L. Sicking, Ronald K. Faller

Nebraska Department of Transportation: Research Reports

No abstract provided.

Biohydrogen Production By The Hyperthermophilic Bacterium Thermotoga Neapolitana, Xiaohui Yu

All Dissertations

ABSTRACT Thermotoga neapolitana can use different sources of carbon and nitrogen for growth and produces biological hydrogen. Sources of carbon (glucose, sucrose, xylose, xylan, cellulose, cellobiose, starch, corn starch, beet bulp pellet, and rice flour) and nitrogen (yeast extract, fish meal, cottonseed meal, canola meal, linseed meal, and soybean meal) were compared. In the carbon studies, glucose, sucrose, rice flour, and xylan produced similar levels of hydrogen. In the nitrogen studies, Trypticase combined with alternative nitrogen sources can efficiently increases the yield of hydrogen produced by Thermotoga neapolitana. Yeast extract with trypticase as the dual nitrogen sources produced significantly increased …

The Microgeometry Parameters Of Uncoated And Zinc-Coated Cold Rolled Steel Strips, J Bidulská, T Kvačkaj, V Bodák, R Bidulský

Journal of Metals, Materials and Minerals

The microgeometry of surface is arithmetically expressed by the arithmetical mean deviation of the profile, Ra and peak count, Pc. Roughening of working rolls was achieved by using the technology EDT (Electric Discharge Texturing) and SBT (Shot Blast Texturing). The paper shows the relationship between the basic microgeometry parameters and the adjustment technology of working rolls. Zinc-coated cold rolled steel strips, uncoated cold rolled steel strips and the Ra, Pc parameters were measured using the tangent profilometer "Hommel Tester T1000". Measurements of Ra and Pc showed the scatter for SBT and EDT rolls, respectively. EDT can provide a considerably greater …

Zn Coatings For Temporary Protection Applied By Peening Technology, J Brezinnová

Journal of Metals, Materials and Minerals

This paper presents actual investigation results of an experiment that aimed at verifying the possibility of applying zinc on steel surface by peening technology using zinc-coated cut wire. A suitable method for obtained zinc layers and evaluation of their corrosion resistance was determined. Accelerated laboratory tests with presence of SO2 and long term working tests in atmospheric conditions were used. Creation of incoherent zinc coatings was established on the bases of metallographic and spectral analysis. The process of cold zinc by peening may serve as temporary anticorrosion protection of steel surface.

Microstructure And Mechanical Properties Of En Aw 6082 Aluminium Alloy Prepared By Equal-Channel Angular Pressing, M Fujda, T Kvačkaj

Journal of Metals, Materials and Minerals

The mechanical properties and microstructure of EN AW 6082 aluminium alloy subjected to severe plastic deformation (SPD) and natural ageing are compared with those of extruded and artificially aged state (initial state) and quenched state of alloy after solution annealing. Quenched state of alloy was deformed at room temperature by equal channel angular pressing (ECAP) following route C up to three passes. Polyedric microstructure of quenched state was considerably changed by SPD. Deformation bands with different amount of deformation were observed in microstructure of ECAPed state, which indicated non-uniform deformation across the cross-section of ECAPed specimen. Ultimate tensile strength (UTS) …

Experimental Methods Of Assessment Of Pvd Coatings Properties, M Hagarová

Journal of Metals, Materials and Minerals

The paper investigates the properties of thin coatings deposited by Physical Vapour Deposition (PVD) technology. This is a modern technology of depositing thin coatings onto the surface of machine parts. Technological procedures of deposition of thin coatings undergo constant improvement. At the same time, new types of coatings are developed. These developments necessitate evaluation of structure, composition and properties of the coatings. The basic methods of determination of properties of thin coatings include determination of their thickness and hardness, structure and chemical analysis, adhesioncohesion and tribological properties.

Fatigue Performance Of High-Temperature Deep-Rolled Metallic Materials, P Juijerm, I Altenberger

Journal of Metals, Materials and Minerals

High-temperature deep rolling was developed from conventional deep rolling (deep rolling at room temperature) and performed on various metallic materials, such as austenitic stainless steel AISI 304, normalized plain carbon steel SAE 1045, aluminium alloys (non-precipitation-hardenable AA5083 and precipitation-hardenable AA6110). The fatigue performance of high-temperature deep-rolled specimens was investigated using stress-controlled fatigue tests and compared with the conventionally deep-rolled condition. It was found that high-temperature deep rolling effectively enhances the fatigue performance of steels. However, for aluminium alloys, the beneficial effects of high-temperature deep rolling are not pronounced due to the different strengthening mechanisms in aluminium alloys.

Finite Element Analysis Study On Effect Of Indenter Tip Radius To Nanoindentation Behavior And Coatings Properties, N Panich, P Wangyao, S Surinphong, Y K. Tan, Y Sun

Journal of Metals, Materials and Minerals

This paper mainly focuses on the study of factors that affect the nanoindentation process and the determination of mechanical properties of coating film using computational finite element (FE) analysis. Attempts have been made in order to show the effect of indenter tip radius on the nanoindentation process of both hard and soft coating systems. It has been proved that larger load is required to reach a specific penetration depth when the indenter tip radius increases. Besides, the change in tip radius led to a more severe effect on hard coating system compared to soft coating system. Furthermore, pile- up and …

Om Study Of Effect Of Hip And Heat Treatments On Microstructural Restoration In Cast Nickel Based Superalloy, In-738, O Wangyao, W Homkrajai, V Krongtong, N Panich, G Lothongkum

Journal of Metals, Materials and Minerals

The present work aims at studying and searching for the most suitable and practicable repairing condition for microstructural restoration, which could provide the desired microstructural characteristics by rejuvenation method of hot isostatic pressing (HIP), followed by 12 heat treatment conditions for long-term serviced gas turbine blades made of cast nickel base superalloy grade IN-738 operated by Electricity Generating Authority of Thailand (EGAT). During heat treatment process, coarse carbides and overexposed coarse gamma prime precipitates, which had formed previously during service, would dissolve into the matrix during solution treatment. Then specimens were processed through a series of precipitation aging, which re-precipitated …

Primary Analysis Of Effective Permeability Of The Flame In Burning Natural Gas, R Jaroslav, R Magdalena

Journal of Metals, Materials and Minerals

This paper presents a method of analysis of effective permeability of the flame in burning natural gas. In order to conduct a complex analysis, it is necessary to determine this parameter as a special case of the process of quasi-plasma nature for the purpose of investigating the options for application of suitable industrial methods applied in similar cases. We observed the synergy of solenoid parameters of the plasma part of the flame with ceramic materials without any special additional customization of the measurement device. The processed results of measurement demonstrate additional requirements necessary for measurement technology. The method was applied …

Localization Of Biliary Tree Structures By Use Of Photon Diffusion Models, Dharmendra Nadkar

Bioengineering Theses - Archive

A novel computational methodology is proposed for the intraoperative localization of biliary tree structures by means of spectrally resolved near-infrared reflectance measurements. As these structures are embedded in fatty tissue, they cannot be visualized directly, which results in inadvertent injuries during a cholecystectomy operation. Localizing the biliary tree intraoperatively is therefore an important clinical problem. Successful clinical implementation of an imaging system which could attain this goal would reduce surgical time, improve patient safety, and minimize the risk of complications and expenses attributable to the current standard practice of intraoperative cholangiography. It is hoped that the work presented here will …

Fabrication Of Robust Superconducting Granular Aluminium/Palladium Bilayer Microbolometers With Sub-Nanosecond Response, Thomas E. Wilson

Physics Faculty Research

We provide a convenient recipe for fabricating reliable superconducting microbolometers as acoustic phonon detectors with sub-nanosecond response, using imagereversal optical lithography and dc-magnetron sputtering, and our recipe requires no chemical or plasma etching. Our approach solves the traditional problem for granular aluminium bolometers of unreliable (i.e., non-Ohmic) electrical contacts by sequentially sputtering the granular aluminium film and then a palladium capping layer. We use dc calibration data, the method of Danilchenko et al. [1], and direct nanosecond-pulsed photoexcitation to obtain the microbolometer’s characteristic current, thermal conductance, characteristic relaxation time, and heat capacity. We also demonstrate the use of the deconvolution …

Experimental Verification Of Source Temperature Modulation Via A Thermal Switch In Thermal Energy Harvesting, Robin Mccarty, D. Monaghan, Kevin P. Hallinan, Brian Sanders

Mechanical and Aerospace Engineering Faculty Publications

This paper provides a description of research seeking to experimentally verify the effectiveness of a thermal switch used in series with TE devices for waste heat recovery for constant and variable source heat input and for variable source thermal capacitance (mass). Using an experimental set-up comprised serially of a fixed heat source, a variable thermal resistance air gap serving as a thermal switch, a thermoelectric device and a heat sink, the time-averaged power output to power input ratios improved up to 15% and 30% respectively for constant and variable heat input in certain design space conditions. The experimental results, as …

A Role Delineation Study For The Sme, Hiral A. Shah

Master's Theses and Doctoral Dissertations

The purpose of this research was to perform a role delineation study to validate and prioritize the competency areas included in the body of knowledge developed by SME/AME/Shingo for their three levels of certification examinations in lean manufacturing. A modified Delphi technique was used to gather data and describe what experts in the field consider important for candidates to know and become certified in the discipline of lean manufacturing. Seventy-six Delphi panel experts were selected to serve on the Delphi panel, based on their experience, expertise, and commitment. The study incorporated a Web-based pre-Delphi study followed by three rounds of …

Using Gis To Optimize The Design And Implementation Of The Rtk Reference Network In Abu Dhabi, Mustafa Abdulla Almusawa

Theses

Several challenging applications and construction works demand real-time measurements for positioning at the centimeter-level accuracy. This positioning accuracy can be obtained by using a Global Positioning System (GPS) roving unit and employing a single reference station (base-station) or through utilizing the service of multiple reference stations forming a Real-Time Kinematics (RTK) Reference Network.

The limitation of the single reference approach is that measurement errors are distance dependent and good accuracy can be only obtained when distances are less than 10 kms. In addition, this method requires a nearby Geodetic Control Point (GCP). Recently, RTK reference networks are widely established in …

Variable Scaling For Time Series Prediction: Application To The Estsp'07 And The Nn3 Forecasting Competitions, Amaury Lendasse, Elia Liitiainen

Engineering Management and Systems Engineering Faculty Research & Creative Works

In This Paper, Variable Selection and Variable Scaling Are Used in Order to Select the Best Regressor for the Problem of Time Series Prediction. Direct Prediction Methodology is Used Instead of the Classic Recursive Methodology. Least Squares Support Vector Machines (LS-SVM) and K-NN Approximator Are Used in Order to Avoid Local Minimal in the Training Phase of the Model. the Global Methodology is Applied to the Estsp'07 Competition Dataset [1] and the Dataset B of the Nn3 Forecasting Competition [2]. ©2007 IEEE.

An Empirical Dependence Mesaures Based On Residual Variance Estimation, Nima Reyhani, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

In This Paper, a Solution to Empirical Dependency Measure is Proposed. the Main Idea is to Use the Notion of Predictability as a Basis for Dependency Definition. Considering Any Nonlinear Regression Function between Two Random Variables, the Power of Regression Residuals or Noise Variance Defines the Desired Dependency Measure. the Residuals Variance Can Be Directly Computed by Estimators Without Finding the Best Fit Curve. the Paper Shows the Conditions on Which Two Random Variables Are Independent According to the Estimated Residuals Variance. the Existence of Residual Variance, or Noise Variance Estimators Make It Possible to Define Such Practical Measure for …

Using Science, Engineering, And Education To Address Water Supply Challenges In The Highlands Of Guatemala, Andrew Curtis Elmore, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

The Guatemalan Highlands is a Popular Destination for Non-Government Organizations Interested in Performing Relief Projects. U.S.-Based Organizations Such as Rotary International, Engineers Without Borders, and Various Religious Organizations Travel to Guatemala to Conduct Humanitarian Activities Which May Be Effective for the Short Term, But It is Not Clear that the Efforts Have a Systematic Impact. Students and Faculty at the University of Missouri-Rolla Have Systematically Studied Water Supply Issues Including Undergraduate and Graduate Research Projects and Undergraduate Engineering Courses Such as International Capstone Design. Materials Engineers Have Been Involved in the Study of Ceramic-Based Water Treatment Devices. These Microfilters Have …

A Hardware Threat Modeling Concept For Trustable Integrated Circuits, Jia Di, Scott C. Smith

Electrical and Computer Engineering Faculty Research & Creative Works

Similar to the effects of software viruses, hardware can also be compromised by introduction of malicious logic into circuits to cause unwanted system behaviors. This can be done by changing or adding internal logic, in such a way that it is undetectable using traditional testing and verification tools and techniques. Therefore, the user of the circuit needs to decide whether it can be trusted, i.e., it only performs functions defined in the original circuit specification (no more and no less), before employing it in the system. in this paper, a preliminary methodology is proposed to model potential hardware threats in …

A Systematic Semi-Numerical Approach For Modeling Of Signal And Power Integrity Of Electronic Packages, Er Ping Li, En Xiao Liu, Zaw Zaw Oo, Xingchang Wei, Yaojiang Zhang, R. Vahldieck

Electrical and Computer Engineering Faculty Research & Creative Works

A novel method for system-level modeling of advanced electronic packages is presented which is able to provide fast yet accurate simulation for signal and power integrity analysis of the multilayered electronic packages. the method is a semi-numerical approach based on the combination of the moment method and the scattering matrix method. © 2007 IEEE.

Detecting Malicious Logic Through Structural Checking, Scott C. Smith, Jia Di

Electrical and Computer Engineering Faculty Research & Creative Works

Hardware is just as susceptible as software to "hacker attacks", through inclusion of malicious logic; and the consequences of such an attack could be disastrous! the impact of software viruses has been felt, at one time or another, by the entire computerized world, through loss of productivity, loss of system resources or data, or mere inconvenience. However, the nature of malicious logic and defending against it is fundamentally different from its software counterpart. Malicious logic has the added dimension of not being removable once encapsulated in the system. This paper will identify hardware vulnerabilities and will outline an automated method, …

Electromagnetic Simulation For Inhomogeneous Interconnect And Packaging Structures, Lijun Jiang, Barry J. Rubin, Yuan Liu, Jason D. Morsey, Alina Deustch

Electrical and Computer Engineering Faculty Research & Creative Works

The paper contains a novel mechanism for full wave electromagnetic simulation of complicated inhomogeneous structures, such as on-chip interconnects, IC packaging, antennas, and scattering objects. It uses only Equivalent Principle based EFIE instead of both EFIE and MFIE to establish the surface integral equations for practical inhomogeneous structure so that a much more simplified formulation process is needed in the EM simulation procedure. To overcome the numerical error of K operator in the formulation, a new analytical solution to the K operator for general full-wave integral equations is provided. Numerical results are demonstrated to verify the proposed algorithm. © 2007 …

Nanofabric Pla Architecture With Redundancy Enhancement, Mandar V. Joshi, Waleed K. Al-Assadi

Electrical and Computer Engineering Faculty Research & Creative Works

Fundamental electronic structures such as Diodes and FETs have been shown to be constructed using selectively doped semiconducting Carbon Nanotubes or Silicon Nanowires (CNTs, SiNWs) at nanometer scale. Memory and Logic cores have been proposed, that use the configurable junctions in 2-D crossbars of CNTs. These Memory and Logic arrays at this scale exhibit a significant amount of defects that account for poor a yield. Configuration of these devices in the presence of defects demands an overhead in terms of area and programming time. This work introduces a PLA configuration that makes use of fixed and adaptive redundancy in terms …

Self-Healing Control With Multifunctional Gate Drive Circuits For Power Converters, Xiao Peng, Ganesh K. Venayagamoorthy, Keith A. Corzine, Robert Woodley

Electrical and Computer Engineering Faculty Research & Creative Works

Many commercial and military transport systems have fault diagnostic functions implemented to help protect the device when a severe fault occurs. However, most present systems do not contain prognostics capability which would allow operators to observe an unhealthy system component in its prefault condition. in industry applications, scheduled downtime can result in considerable cost avoidance. the next technology step is self-healing system components which observe not only potential problems but can also take steps to continue operation under abnormal conditions - whether due to long-term normal wear-and-tear or sudden combat damage. in this paper, current and voltage information using the …

2006 Summary Of Highway Revenues, Distributions, & Expenses For Indiana Counties, Cities, & Towns, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This report provides information on revenues, distributions, and expenses of state and local governments for highway, road, and street work. Since the Motor Vehicle Highway (MVH) and Local Road and Street (LRS) Accounts are the principal source of funds for local road or street construction and maintenance operations, this summary may be used to see the trends in income sources and in the expenses charged to the funds prior to their being distributed to the highway, road, and street agencies.

Design Of An Active Orthotic Device For Joint Management., Steven Clayton Anderson

Electronic Theses and Dissertations

Existing treatment programs and procedures are incapable of addressing the complications encountered with patients who experience spasticity and hypertonia related joint contractures. Current passive therapy procedures and devices are only capable of managing the extent of joint contractures on patients with chronic and acute onset severe neurological disorders. The project was conceived as a means to develop an active device that is capable of adapting to the state of the joint to mange the extent of contractures and to permit consideration for the prevalence of spastic activity episodes and hypertonia. The project focused on the design of the physical prototype …

A Practical Guideline For Establishing Non-Return Valve Specification And Performance Criteria, Eric W. Dawkins

Masters Theses

The non-return valve has been a standard piece of equipment in the injection molding industry since the reciprocating screw was developed. Most molders understand the role of the non-return valve in the molding process. But few understand the functional problems of the non-return valve. Because of this, the non-return valve has been considered a nuisance item for injection molders.

Wear of the non-return valve is another problem that molders are faced with. The factors contributing toward wear are not entirely understood. Material, temperatures, hours and machine size, etc., all effect the life of a valve. Consequently, most worn valves are …