Engineering Commons^™

Optical Properties Of Ceo2 Films Prepared From Colloidal Suspension, V. Petrovsky, B. P. Gorman, Harlan U. Anderson, T. Petrovsky

Materials Science and Engineering Faculty Research & Creative Works

Electronic Materials Applied Research Center, University of Missouri-Rolla, Rolla, Missouri 65409-1170 Optical absorption of nanocrystalline thin films can be influenced by the presence of both porosity and grain size effects. If both are present simultaneously, their effects are difficult to separate. In this study it is shown that the combination of uv-vis transmittance and reflectance measurements on porous CeO₂ films provides enough data to make this separation. The CeO₂ films were prepared by deposition of nanosized (∼5 nm) particles from a water colloidal suspension onto sapphire and subjecting these films to sintering temperatures sufficiently high to provide a …

A Decomposition Approach For The Multi-Modal, Resource-Constrained, Multi-Project Scheduling Problem With Generalized Precedence And Expediting Resources, Michael L. Fredley

Theses and Dissertations

The field of project scheduling has received a great deal of study for many years with a steady evolution of problem complexity and solution methodologies. As solution methodologies and technologies improve, increasingly complex, real-world problems are addressed, presenting researchers a continuing challenge to find ever more effective means for approaching project scheduling. This dissertation introduces a project scheduling problem which is applicable across a broad spectrum of real-world situations. The problem is based on the well-known Resource-Constrained Project Scheduling Problem, extended to include multiple modes, generalized precedence, and expediting resources. The problem is further extended to include multiple projects which …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 18, Number 1, September 2001, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Implicit Algorithms For Multi-Valued Input Support Manipulation, Alan Mishchenko, Craig Files, Marek Perkowski, Bernd Steinbach, Christina Dorotska

Electrical and Computer Engineering Faculty Publications and Presentations

We present an implicit approach to solve problems arising in decomposition of incompletely specified multi-valued functions and relations. We introduce a new representation based on binaryencoded multi-valued decision diagrams (BEMDDs). This representation shares desirable properties of MDDs, in particular, compactness, and is applicable to weakly-specified relations with a large number of output values. This makes our decomposition approach particularly useful for data mining and machine learning. Using BEMDDs to represent multi-valued relations we have developed two complementary input support minimization algorithms. The first algorithm is efficient when the resulting support contains almost all initial variables; the second is efficient when …

Intelligent Transportation Systems Business Plan For Kentucky (Final Report), Jennifer R. Walton, Joseph D. Crabtree, Monica L. Barrett, Jerry G. Pigman

Kentucky Transportation Center Research Report

This report presents a Business Plan for Intelligent Transportation Systems (ITS) in Kentucky. The purpose of the Business Plan is to define ITS projects that are planned for implementation from 2002 through 2007. The list of projects contained within this document was developed using Kentucky’s ITS Strategic Plan, the ITS National Architecture, and stakeholder input.

There are 21 projects planned for implementation over the next 6 years at a total estimated cost of nearly $80 million. Another five projects will be considered when the Business Plan is updated in two years. These projects cover a wide range of topics including: …

Analysis Of Traffic Crash Data In Kentucky (1996-2000), Kenneth R. Agent, Jerry G. Pigman, Monica L. Barrett

Kentucky Transportation Center Research Report

This report documents an analysis of traffic crash data in Kentucky for the years of 1996 through 2000. A primary objective of this study was to determine average crash statistics for Kentucky highways. Average and critical numbers and rates of crashes were calculated for various types of highways in rural and urban areas. These data can be used in Kentucky’s procedure to identify locations that have abnormal rates or numbers of crashes.

The other primary objective of this study wa s to provide data which can be used in the preparation of the problem identification portion of Kentucky’s Annual Highway …

The Paris To Lexington Road Reconstruction Project, Raymond F. Werkmeister, Donn E. Hancher

Kentucky Transportation Center Research Report

This report summarizes the effort to provide the Kentucky Transportation Cabinet with an evaluation of the results obtained for the Paris to Lexington Road Reconstruction Project from 1997 to 2001. A unique pre-qualification process was used for the project to select a fixed pool of contractor to provide input to the design and to bid on the work. The research started in 1996 during the design process and continued following construction until September of 2001.

Input was received from the Cabinet personnel working on the project, from the design firms, from the contractors, from the property owners involved, and from …

Institutional And Other Constraints To Non-Oil Exports., R. O. Madaki

Bullion

This paper examines the non-oil exports sector in Nigeria which had witnessed a lacklustre performance despite the several statements of government's interest in export-biased growth strategy and the establishment of several export facilitating institutions. The paper further observes that a major problem with Nigeria's non-oil export sector is that it is not predicated on the design and implementation of appropriate and coherent economic policies as there is no clear export promotion blue print in Nigeria. Consequently, the sector is facing a number of institutional and other domestic and external problems. The remaining part of the paper briefly highlight some of …

Watershed Management Technique To Control Sediment Yield In Agriculturally Dominated Areas, John W. Nicklow, Misgana K. Muleta

Civil and Environmental Engineering

Non-point source pollution is recognized internationally as a critical environmental problem. In Illinois, soil erosion from agricultural lands is the major source of such pollution. The erosion process, which has been accelerated by human activity, tends to reduce crop productivity and leads to subsequent problems from deposition on farmlands and in water bodies. Comprehensive watershed management, however, can be used to protect these natural resources. In this study, a discrete time optimal control methodology and computational model are developed for determining land use and management alternatives that minimize sediment yield from agriculturally-dominated watersheds. The solution methodology is based on an …

Determining Matric Stress With The Modified Cam Clay Energy Relationship, Richard A. Rohlf, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

The stress generated by matric suction, or matric stress, was determined at points along the stress path with an analytical and experimental procedure based on the modified Cam clay energy relationship. Matric stress was found to be approximately constant at large strain for constant water content triaxial compression tests. Matric stress was included in both shear and volume relationships in a critical–state soil model that employed the modified Cam clay yield function. Shear was modeled with a constant matric stress. Slope of the normal compression and recompression lines was adjusted for matric stress using a state function that expressed matric …

Proxy Servers For Scalable Interactive Video Support, Husni Fahmi, Mudassir Latif, Sahra Sedigh, Arif Ghafoor, Peiya Liu, Liang Hsu

Electrical and Computer Engineering Faculty Research & Creative Works

Targeting scalability, load balance and resource efficiency in streaming multimedia applications, proxy servers facilitate faster real-time access to cached objects and reduce response time to document requests.

Using Neural Networks To Estimate Wind Turbine Power Generation, Shuhui Li, Donald C. Wunsch, Edgar O'Hair, Michael G. Giesselmann

Electrical and Computer Engineering Faculty Research & Creative Works

This paper uses data collected at Central and South West Services Fort Davis wind farm to develop a neural network based prediction of power produced by each turbine. The power generated by electric wind turbines changes rapidly because of the continuous fluctuation of wind speed and direction. It is important for the power industry to have the capability to perform this prediction for diagnostic purposes—lower-than-expected wind power may be an early indicator of a need for maintenance. In this paper, characteristics of wind power generation are first evaluated in order to establish the relative importance for the neural network. A …

Bs News

Building Services Engineering

No abstract provided.

Theater-Level Stochastic Air-To-Air Engagement Modeling Via Event Occurrence Networks Using Piecewise Polynomial Approximation, David R. Denhard

Theses and Dissertations

This dissertation investigates a stochastic network formulation termed an event occurrence network (EON). EONs are graphical representations of the superposition of several terminating counting processes. An EON arc represents the occurrence of an event from a group of (sequential) events before the occurrence of events from other event groupings. Events between groups occur independently, but events within a group occur sequentially. A set of arcs leaving a node is a set of competing events, which are probabilistically resolved by order relations. An important EON metric is the probability of being at a particular node or set of nodes at time …

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials: Aaa Task-4 Quarterly (June 1 – August 31, 2001) Report, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The subject task entitled “Hydrogen-Induced Embrittlement of Candidate Target Materials for Applications in Spallation-Neutron-Target Systems” had commenced during the quarter ending on August 31, 2001. A research account has been established, contracts for both faculty and students have been prepared, and efforts are well underway to embark on the related research activities, as proposed.

As the title of this project implies, the primary objective of this task is to evaluate the effect of hydrogen on environment-assisted cracking of candidate materials for applications in spallationneutron- target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). …

Dsp-Based Field-Oriented Step Motor Control, Daniel J. Simon, Dennis L. Feucht

Electrical and Computer Engineering Faculty Publications

The SMC3 motor drive has been built using an Analog Devices ADSP-2101 digital signal processor (DSP). The SMC3 is designed to work with two-phase step motors, which are permanent magnet motors with many (typically 100) poles. The firmware in the SMC3 DSP drives the step motor phase windings using field-oriented control rather than using single steps. This method derives the maximum theoretical performance from the motor. This paper describes field-oriented control, and how the SMC3 hardware and firmware implements it.

Microfocal X-Ray Ct Imaging And Pulmonary Arterial Distensibility In Excised Rat Lungs, Kelly L. Karau, Roger H. Johnson, Robert C. Molthen, Anita H. Dhyani, Steven Thomas Haworth, Christopher C. Hanger, David L. Roerig, Christopher A. Dawson

Biomedical Engineering Faculty Research and Publications

The objective of this study was to develop an X-ray computed tomographic method for measuring pulmonary arterial dimensions and locations within the intact rat lung. Lungs were removed from rats and their pulmonary arterial trees were filled with perfluorooctyl bromide to enhance X-ray absorbance. The lungs were rotated within the cone of the X-ray beam projected from a microfocal X-ray source onto an image intensifier, and 360 images were obtained at 1° increments. The three-dimensional image volumes were reconstructed with isotropic resolution using a cone beam reconstruction algorithm. The vessel diameters were obtained by fitting a functional form to the …

Development Of An Integrated Photonic Sensor For Monitoring Hazardous Organics, Dianhong Luo

Dissertations

In this study, an integrated photonic sensor has been designed and fabricated for the purpose of monitoring hazardous organics in the environment. The operation of the sensor is based on the principles of the Mach-Zehnder interferometry. The sensor consists of a patterned waveguide structure made of phosphosilicate core and silica cladding. LPCVD processes were developed to produce undoped cladding and doped core silicon dioxide films. Diethylsilane (DES), Trimethylphosphite (TMP) and oxygen were used as the precursors for the deposition process. The effects of the O₂/DES ratio and deposition temperature on the properties Of SiO₂ films were investigated. …

Buckling Of Composite Conical Shells Under Combined Axial Compression, External Pressure, And Bending, Youngjin Chung

Dissertations

Conical shells are extensively used in space crafts, robots, shelters, domes, tanks, and in machinery or devices (e.g. as Belleville washers). Thus, the design of minimum weight, maximum strength, stiffened conical (and cylindrical) shells under combined loads has long been of interest to designers. The objective of this study is to improve the strength of conical shells and reduce the weight of the structure. Buckling of composite conical shells subjected to combined axial loading, external pressure, and bending is investigated using energy and finite element methods. The conical shells have single and multiple layers, different cone angle, length, and radius. …

Arq Protocol For Joint Source And Channel Coding And Its Applications, Bin He

Dissertations

Shannon's separation theorem states that for transmission over noisy channels, approaching channel capacity is possible with the separation of source and channel coding. Practically, the situation is different. Infinite size blocks are needed to achieve this theoretical limit. Also, time-varying channels require a different approach. This leads to many approaches for source and channel coding. This dissertation will address a joint source and channel coding that suits Automatic Repeat Request (ARQ) application and applies it to packet switching networks. Following aspects of the proposed joint source and channel coding approach will be presented:

1. The design of the proposed joint source …

Evolutionary Polymorphic Neural Networks In Chemical Engineering Modeling, Li Gao

Dissertations

Evolutionary Polymorphic Neural Network (EPNN) is a novel approach to modeling chemical, biochemical and physical processes. This approach has its basis in modern artificial intelligence, especially neural networks and evolutionary computing. EPNN can perform networked symbolic regressions for input-output data, while providing information about both the structure and complexity of a process during its own evolution.

In this work three different processes are modeled: 1. A dynamic neutralization process. 2. An aqueous two-phase system. 3. Reduction of a biodegradation model. In all three cases, EPNN shows better or at least equal performances over published data than traditional thermodynamics /transport or …

Integration Of E-Business Strategy For Multi-Lifecycle Production Systems, Yanchun Luo

Dissertations

Internet use has grown exponentially on the last few years becoming a global communication and business resource. Internet-based business, or e-Business will truly affect every sector of the economy in ways that today we can only imagine. The manufacturing sector will be at the forefront of this change. This doctoral dissertation provides a scientific framework and a set of novel decision support tools for evaluating, modeling, and optimizing the overall performance of e-Business integrated multi-lifecycle production systems. The characteristics of this framework include environmental lifecycle study, environmental performance metrics, hyper-network model of integrated e-supply chain networks, fuzzy multi-objective optimization method, …

Saturation Routing For Asynchronous Transfer Mode (Atm) Networks, Jose Luis Ucles

Dissertations

The main objective of this thesis is to show that saturation routing, often in the past considered inefficient, can in fact be a viable approach to use in many important applications and services over an Asynchronous Transfer Mode (ATM) network. For other applications and services, a hybrid approach (one that partially uses saturation routing) is presented. First, the minimum effects of saturation routing are demonstrated by showing that the ratio, defined as f, of routing overhead cells over information cells is small even for large networks. Second, modeling and simulation and M/D/l queuing analysis techniques are used to show that …

High Solid Loading Aqueous Base Metal/Ceramic Feedstock For Injection Molding, Mohammad Behi

Dissertations

Increasing volume fraction of metal powder in feedstock provided lower shrinkage. Reduction of the shrinkage results in better dimensional precision. The rheology of the feedstock material plays an important role to allowing larger volume fractions of the metal powder to be incorporated in the feedstock forinulations. The viscosity of the feedstock inainly depends on the binder viscosity, powder volume fraction and characteristics of metal powder.

Aqueous polysaccharide agar was used as a baseline binder system for this study.The effect of several gel-strengthening additives on 1.5wt% and 2wt% agar gel was evaluated. A new gel-strengthening additive was found to be the …

Modeling And Experimental Validation Of A Single-Feed Semi-Batch Precipitation Process, Ernesto Uehara-Nagamine

Dissertations

Crystallization is a widely practiced unit operation throughout the chemical and pharmaceutical process industries. Despite its widespread application, crystallization still suffers a disproportionate number of process difficulties due to the complexity of the steps involved in the process. In particular, the final characteristics of the product are strongly affected by the mixing conditions during the process. The development of a validated modeling approach would be highly valuable for the successful prediction of the crystal characteristics under differing mixing conditions.

In the present work, the single-feed semi-batch precipitation process of barium sulfate in a stirred tank was experimentally studied and numerically …

Initial Hertzian Characteristics Of The Human Tooth As A Damage Tolerant Bio-Ceramic/Bio-Composite Bi-Layer, Ivory Camille Kilpatrick

Theses

The objective of this thesis was to investigate the Hertzian Contact response of human teeth and how the response behavior is related to that of model ceramic bi-layers (high modulus brittle ceramics on compliant substrates). Hertzian Contact is a blunt indentation method, which uses a hard spherical indenter to apply a normal compressive load. Clinical variables of masticatory (occlusal) force and cuspal curvature identify closely with the independent Hertzian variables of contact load and sphere radius [1]. This method offers insight into the role of microstructure and microstructure- sensitive mechanical properties. It was hypothesized that tooth damage modes and patterns …

Dynamic Friction Of Uhmwpe Angular Compliant Bearing For Joint Implants And Machinery, Max Roman

Theses

The feasibility of a unique design of orthopedic- joint implant is investigated. The work focuses on the dynamic friction characteristics of a new joint. This unique design can be also useful in machinery involving oscillating motion similar to that of the hip joint during walking. An elastomeric layer bonded behind the rigid acetubular cup can be beneficial in improving the durability of prosthetic implants. Angular compliance offered by the elastomeric layer reduces relative sliding between the surfaces, lowers contact stresses by distributing pressure more evenly, and reduces the possibility of incongruent loading conditions caused by misalignment. The application of a …

Characterization Of Alpha And Beta Phases Of Tantalum Coatings, Anto Yohannan

Theses

Sputtered tantalum forms two phases - α and β. The α and β phases have distinctly different crystalline structures and properties. The structure and the causes of formation of the β phase are still being studied by researchers. This is a study to distinguish and characterize these two phases. Samples from Bennet Labs and NJIT were characterized using techniques such as SEM, EDX, XRF, XRD, TEM and XAFS. Samples deposited at NJIT were used for an experimental study on the conditions favoring the formation of the phases, by depositing tantalum on heated steel and silicon substrates, additionally TEM analysis was …

Mechanical Design Of The Heater Used In Near Infrared Filter, Jun Ma

Theses

This thesis presents a design and analytical process in the application of the heater used in a near infrared filter working in Big Bear Solar Observatory, CA. The objective of the project is to achieve the physics parameters for the filter, which will be used in the observation of the solar activity.

The most important part of this design is to keep a relatively fixed temperature inside the oven-like heater. The reason is that optical properties of calcite (kind of filter in telescope) are pretty sensitive to a tiny disturbance on inside temperature. This was the biggest issue in this …

Encoding And Storage Components Of Verbal Working Memory As Revealed By A Factorial Design, An Fmri Study, Jason Steffener

Theses

In this fMRI study, the contributions of frontal and posterior brain regions to verbal working memory were investigated. A two-factor design with low and high memory load (2 and 5 letters) and short and long delay (4 and 12 secs.) as factors were used. Based on reports in the literature, we expect activity in the following frontal and parietal brain regions of interest (ROIs): Brodmann areas (BA) 6, 9, 46, 44, 45, 7 and 40. The analysis of collected flvM data involved image processing and statistical analysis methods including realignment, spatial normalization, spatial smoothing, temporal filtering, intensity normalization, statistical tests, …