Engineering Commons^™

Investigation Of Formation And Applications Of High-Speed Liquid Projectiles, Oleg Petrenko

Dissertations

The work comprises experimental and numerical studies of generation and application of high-speed liquid projectiles. Numerical models were created for a projectile formation by two kinds of launchers, water extruder and water cannon. In the water extruder the kinetic energy of a fast moving piston is transferred to the water load and extrudes the load at a high speed. By contrast in the water cannon the water load itself accumulates the kinetic energy from the expanding combustion gasses. Then, in the course of water motion through the converging nozzle the energy is redistributed between head and tail of the projectile. …

Doppler Spread Estimation In Mobile Fading Channels, Hong Zhang

Dissertations

The Doppler spread, or equivalently, the mobile speed, is a measure of the spectral dispersion of a mobile fading channel. Accurate estimation of the mobile speed is important in wireless mobile applications which require such as knowledge of the rate of channel variations. In this dissertation, first the performance of classical crossing- and covariance-based speed estimators is studied. Next, the problem of mobile speed estimation using diversity combining is investigated. Then, a nonparametric estimation technique is proposed that is robust to different channel variations. Finally, cyclostationarity-based speed estimators which can be applied either blindly or with the aid of pilot …

Reactive Modification And Crystallization Behavior Of Foamed Poly(Butylene Terephthalate), Byeong Joon Jeong

Dissertations

The objective of this study is to investigate the feasibility of preparing low density foams based on poly(butylene terephthalate) (PBT) through modification of its molecular structure and rheological characteristics by reactive extrusion. The scientific and/or engineering interpretation of the experimental data was based on fundamentals of extrusion, crystallization mechanisms, as well as information on reactivity and tendency toward degradation of PBT.

As a preliminary study, the extrusion foaming behavior of a commercial linear semi-crystalline PBT with a chemical blowing agent (CBA) was investigated. Foam characteristics were functions of extrusion operational variables, such as die set temperature and screw speed. Gas …

Flow Characteristics And Phase Interactions Of Evaporating Sprays In Gas-Solid Suspensions, Muhammad Mushahid Rafique Qureshi

Dissertations

Evaporating spray jets have a wide range of applications in many industrial processes such as fluidized catalytic cracking of crude oil in petroleum refinery, coal gasification, fluidized coking to make synthetic crude oil, and condensed mode gas polymerization. The rapid evaporation of spray jets significantly affects the gas-solids mixing, solids concentration, gas/solids temperature and gas/solids velocity acceleration. The complex interactions mechanism of phase change, three phase interaction, heat and mass transfer of gas, solids and evaporating droplets dominate the process efficiency and product quality. In such three-phase flows, the phase transport characteristics are influenced by both droplet-gas interaction and droplet-solid …

Solubility In Supercritical Carbon Dioxide, Syed Asif Abdullah

Theses

The different techniques used for the determination of the solubility of compounds in supercritical carbon dioxide are described. A comparative study is made of the methods used in the measurement of the concentration of benzoic acid and caffeine in supercritical carbon dioxide. The difference in measurement techniques did not have much effect on the solubility data at lower pressures. However, at higher pressures, the solubility data obtained by different techniques began to deviate from each other.

Further, the method used by different researchers in generating the solubility data in supercritical carbon dioxide is also discussed. A number of data sheets …

A Kinematic Analysis Of Sign Language, Chemuttaai C. Koech

Theses

Signed languages develop among deaf populations and employ manual communication instead of voiced communication. Stokoe attributes classify individual signs in American Sign Language (ASL) and include handshape, hand location, movement, orientation, and facial expression. Signed and oral languages are not mutually understood, and many deaf individuals live in linguistic isolation. This research addresses computer translation between signing and speech, investigating sign duration in sentence context versus in isolation and identifying kinematic sign markers. To date, there has been little study of continuous signing kinematics; it was previously unknown if kinematic markers existed.

Kinematic data were collected from a proficient signer …

Jet Assisted Fluidization Of Nanoparticle Agglomerates, Ayokunle O. Omosebi

Theses

Fluidization serves as a primary operation used to disperse, handle and process nanoparticles, but due to the complications involved with achieving homogenous fluidization of the agglomerates of nanoparticles, several methods have been developed to assist their conventional mode of fluidization.

In this work, the conventional mode of fluidization was coupled with secondary gas flow emerging from a micro jet nozzle. The effect of the jet on the fluidization behavior of various APF and ABF nanopowders was studied and compared with the pure conventional fluidization mode. Generally, experiments were conducted to find the optimal operation of the jet by varying parameters …

Non-Repudiation Secure File Transfer Protocol (Nrsftp), Jerry Chen

Theses

Non Repudiation Secure File Transfer Protocol (NRSFTP) is designed to resolve three main concerns for today's electronic file transfer methodology. The three main concerns are Non-Repudiation, Secure, and Non-Real Time file transfer. Non-repudiation is to assure the receiver that the sender of the document is not an imposter. Secure document transfer is to assure the sender that only the intended receiver will be able to read the document. Non-real-time file transfer is to provide convenient and low cost transportability of the encrypted data from one party to another. With the above three concerns addressed, the NRSFTP protocol can be widely …

Numerical Analysis Of The Operation Of A Water Cannon, Teymuraz G. Bitadze

Theses

This study was designed to investigate the operational process of a launcher for generation of high speed water projectiles, and it involved the optimization of the geometry of a launcher body. The objective of the optimization of the internal geometry was to increase the effective momentum of the projectile while the optimization of the external geometry resulted in the reduction of the mass of the launcher.

In the course of the optimization of the internal geometry the exit velocity variation was determined, and used to compute an effective projectile momentum, which actually affects a workpiece. In this research, it was …

Determining Continual Improvement Process Methods Within Quality Management Systems, Diane M. Bové

Theses

Institutionalized standards require organizations to actively define and implement quality management systems, which includes active participation in continual improvement efforts. Interpretations and practices vary on implementation methodology.

Traditional views of quality do not integrate the technical disciplines into a defined science which would support a standardized approach for continual improvement implementation.

In order to optimize improvement efforts, a conceptual hypothesis is proposed to integrate quality through combining and collaborating implementation efforts of engineering, control, assurance, improvement and costs. The purpose of this thesis is to establish a roadmap to assist in choosing effective quality improvement methodologies and toolsets that assist …

Channel-Predictive Link Layer Arq Protocols In Wireless Networks, Huseyin Dogukan Cavdar

Theses

Communication performance over a wireless channel should be considered according to two main parameters: energy and throughput. The reliable data transfer is a key to these goals. The reliable node-to-node data transfer is performed by link layer protocols. One prominent approach is Automatic Repeat Request (ARQ) protocol. The traditional ARQ protocols attempt to recover the erroneously transmitted frames by retransmitting those frames, regardless of the channel state. Since this channel state unaware behaviour may cause unnecessary retransmissions, traditional ARQ protocols are expected to be energy inefficient. Some ideas have been proposed such as stochastic learning automaton based ARQ, and channel …

A Dynamic Supine Stander For Subjects With Disabilities Leading To Prolonged Immobility, Luis Alberto Espina

Theses

Bone tissue needs to be exposed to loading in order to stimulate the osteogenic response of the body. Disabilities that lead to prolonged immobility will result in a decrease of the osteogenic processes and an increase in resorption of bone by osteoclast cells. This disuse modeling can lead to osteopenia, osteoporosis, and subsequent non-traumatic fractures. These disabilities are varied in nature and duration, and can include load bearing bone fracture, excessive obesity, spinal cord injury, and cerebral palsy.

The following describes the concept and design of a novel dynamic supine stander that will provide loads simulating ambulation to the lower …

Functionalization Of Nanoclays Through Exchange Reactions, Jin Uk Ha

Theses

A cationic clay (sodium-montmorillonite, MMT) and an anionic clay (hydrotalcite, HT) were treated with two phosphonium based ionic liquids (ILs) and a commercial corrosion inhibitor. Clay modification was examined by TGA, FTLR and WXRD. The cationic clay modified with both ILs had similar thermal stabilities since they contained the same cation although the original anions were different. The thermal stability of the modified clays was higher than that of a commercial organoclay and of clays modified in our group with smaller MW pyridinium and imidazolium based cations. 10 wt% of interchanged cation was found under selected time/temperature treatment conditions.

Clays …

Burmester Curve And Numerical Motion Generation Of Grashof Mechanisms With Perimeter And Transmission Angle Optimization In Mathcad, Peter J. Martin

Theses

An infinite number of planar four-bar mechanism solutions exist for a series of prescribed rigid-body positions. Given a set of Burmester curves or numerically-generated fixed and moving pivot curves, sorting through the limitless number of possible mechanism solutions to find one that ensures full link rotatibility, satisfies compactness criteria and produces feasible transmission angles can be a daunting task. In this work, two algorithms are developed and presented by which the user can select optimum planar four-bar motion generators (optimum with respect to Grashof criteria, mechanism perimeter criteria and transmission angle criteria) from a set of all mechanism solutions produced …

Inverse Solid-Liquid Fluidization Of Aerogel Granules And Its Application In Removing Oil From Water, Gaurav Babubhai Patel

Theses

Fluidization is a very well known unit operation used in the chemical industry for various purposes. Inverse solid-liquid fluidization, where the solid particles to be fluidized are less dense than the fluid, is one of the several different kinds of fluidization being studied for its potential in industrial applications. The present work focuses on finding the hydrodynamic characteristics (minimum fluidization velocity, bed expansion and pressure drop) of an inverse fluidized bed of aerogel granules and using this system to remove oil from an oil-water mixture. The solid particles employed for this study are low density (100 kg/m³) surface …

Multi-Degree Of Freedom Telemanipulation In An Unstructured Environment, Diego Ramirez

Theses

Two approaches to 6-degrees-of-freedom telemanipulation that will accommodate different needs and skills of potential users with congenital amputation, arthrogryposis, muscular dystrophy and cerebral palsy were developed. One method uses scalable movements (i.e. position and orientation), and the second employs isometric forces and torques without movement. The scalable position approach employs a 6-degress-of-freedom electromechanical stylus whose joint orientations are used by the controlling computer to determine the position and orientation of the robot's end effector via inverse kinematics or by one-to-one matching of the stylus joint angles with those of the manipulator. The isometric method uses the measured forces and torques …

Implementation Of Stereo Correspondence Algorithms For Multi-Baseline Vision System, Navaneetha Shivram

Theses

The purpose of this study is to determine the impact of varying camera baselines on correspondence and depth estimation. As the baseline increases the resolution of depth increases but finding correspondences is very tedious. On the other hand when cameras are placed close to each other and thereby reducing the baseline distance points in the images are easily matched however depth resolution deteriorates. This problem is solved by using a multi-camera system is used in which the cameras are spaced close to each other along a straight line. Calculating the correspondence along successive camera pairs is relatively easy. These respondences …

Inverse Dynamic Modeling For Characterization Of Spasticity, Katharine Markel Swift

Theses

Spasticity affects subjects with cerebral palsy, stroke, multiple sclerosis, and traumatic brain injury. The need to develop a deeper understanding of spasticity is driven by the existing limited understanding and the lack of satisfactory interventions for this disabling phenomenon.

An inverse model is implemented to describe the motion in the pendulum knee drop test. Inverse kinematic modeling is implemented to investigate the pathophysiology of spasticity.

Using the equilibrium point hypothesis as a conceptual framework to explain disabled and non-disabled neuromuscular control, it has been demonstrated that the equilibrium point of the passive knee is dynamic and exhibits a pseudo-exponential trajectory …

Ceas E-News 01.30.2007, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

WMU's first female engineering grad shares secrets to success

Recent Progress In The Development Of Incits W1.1, Appearance-Based Image Quality Standards For Printers, Elisa H. Barney Smith

Electrical and Computer Engineering Faculty Publications and Presentations

In September 2000, INCITS W1 (the U.S. representative of ISO/IEC JTC1/SC28, the standardization committee for office equipment) was chartered to develop an appearance-based image quality standard.^(J),(2) The resulting W1.1 project is based on a proposal⁽⁴⁾ that perceived image quality can be described by a small set of broad-based attributes. There are currently five ad hoc teams, each working towards the development of standards for evaluation of perceptual image quality of color printers for one or more of these image quality attributes. This paper summarizes the work in progress.

Nanofibrous Articles, Gene Kim, Bonnie Bachman, Stephen O. Bozzone

Economics Faculty Research & Creative Works

Nanofibrous articles can be manufactured by a process that includes preparation of a surface of a substrate to provide an adhesion mechanism for securing the nanofibers to the surface. The nanofibers can be dispersed in an area near the substrate for the purpose of being adhered to the surface. If an ordered arrangement of nanofibers is required, an electric field can be provided in the area where the nanofibers are dispersed to selectively control an ordering of the nanofibers as they are adhered to the surface by the adhesion mechanism.

Nevada Risk Assessment/Management Program (Nramp) – Phase 2: Quarterly Progress Report, Oct. 1, 2006- Dec. 31, 2006, Klaus J. Stetzenbach

Nevada Risk Assessment/Management Program

Work conducted in this initial period consisted of work start-up (technical, administrative, contractual), and interviewing/site visits with DOE NVO staff (and support contractors) and HRC staff to quickly ascertain current technical activities and priorities as related to the scope of this task.

Since much of the technical work scope builds on previous technical work, it was considered critical to determine the changes (programmatic, technical, and regulatory) that have occurred over the past several years that directly relate to the scope. It was also equally important to determine the technical and programmatic priorities that have been established in the interim.

High Temperature Heat Exchanger Project: Quarterly Progress Report October 1, 2006 Through December 31, 2006, Anthony Hechanova

Publications (NSTD)

Modifications to the single-channel models of the Ceramatec heat exchanger and decomposer concept for hexagonal flow channels under two values of layer-overlapping (50% and 100%) and for diamond-shaped flow channels were completed.

The finite element calculations of the “Ball on Three Ball Test” for ceramic material for the purpose of selecting the appropriate specimen thickness for future experimental testing was performed for plate thicknesses ranging from 2 to 8 mm.

A finite element model of the “Ball on Three Ball Test” was also studied for discs having micro-channels.

Distributed Video Coding Based On Constrained Rate Adaptive Low Density Parity Check Codes, Rong Ke Liu, Guo Gang Hua, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

Distributed video coding is an emerging area of research for digital video driven partly by the widespread use of video acquisition devices by the consumers. In this paper, we present a distributed video coding scheme based on zero motion identification at the decoder and constrained rate adaptive low density parity check (LDPC) codes. Zero-motion-block identification mechanism is introduced at the decoder, which takes the characters of video sequence into account. The constrained error control decoder can use the bits in the zero motion blocks as a constraint to achieve a better decoding performance and further improve the overall video compression …

Effect Of Initial Surface Treatment Timing On Chloride Concentrations In Concrete Bridge Decks, Aimee Worthen Birdsall

Theses and Dissertations

Bridge engineers and managers in coastal areas and cold regions frequently specify the application of surface treatments on concrete bridge decks as barriers against chloride ingress. In consideration of concrete cover thickness and the presence of stay-in-place metal forms (SIPMFs), the objective of this research was to determine the latest timing of initial surface treatment applications on concrete bridge decks subjected to external chloride loading before chlorides accumulate in sufficient quantities to initiate corrosion during the service life of the deck. Chloride concentration data for this research were collected from 12 concrete bridge decks located within the I-215 corridor in …

Dynamic Gop Structure For Scalable Video Coding, Haksoo Kim, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

MPEG is currently developing a new scalable video coding (SVC) standard which should provide compression efficiency similar to current non-scalable video coding standard. The extension of H.264/AVC hybrid video coding using motion-compensated temporal filtering (MCTF) is a current solution. This paper presents a dynamic group of picture (GOP) structure to improve the quality of the SVC coded video by using variable GOP sizes along the video sequences without the restriction of the fixed GOP size or the limited adaptive GOP size. The dynamic GOP structure keeps temporal importance information of frames in the encoded video, which helps in coding efficiency …

How Does The Coupling Of Secondary And Tertiary Interactions Control The Folding Of Helical Macromolecules?, Vikas Varshney, Gustavo A. Carri

College of Polymer Science and Polymer Engineering

The authors study how the simultaneous presence of short-range secondary and long-range tertiary interactions controls the folding and collapse behavior of a helical macromolecule. The secondary interactions stabilize the helical conformation of the chain, while the tertiary interactions govern its overall three-dimensional shape. The authors have carried out Monte Carlo simulations to study the effect of chain length on the folding and collapse behavior of the chain. They have calculated state diagrams for four chain lengths and found that the physics is very rich with a plethora of stable conformational states. In addition to the helix-coil and coil-globule transitions, their …

Progressive Image Transmission With Rcpt Protection, Lei Yao, Lei Cao, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

In this paper, a joint source-channel coding scheme is proposed for progressive image transmission over channels with both random bit errors and packet loss by using rate-compatible punctured Turbo codes (RCPT) protection only. Two technical components which are different from existing methods are presented. First, a data frame is divided into multiple CRC blocks before being coded by a turbo code. This is to secure a high turbo coding gain which is proportional to the data frame size. In the mean time, the beginning blocks in a frame may still be usable although the decoding of the entire frame fails. …

Evaluation Of Stent Design Based On The Haemodynamic Effect Of Coronary Stenting, Jonathan Murphy, Fergal Boyle

Conference Papers

No abstract provided.

Tunneling Anisotropic Magnetoresistance Driven By Resonant Surface States: First-Principles Calculations On An Fe(001) Surface, Athanasios N. Chantis, Kirill D. Belashchenko, Evgeny Y. Tsymbal, Mark Van Schilfgaarde

Nebraska Center for Materials and Nanoscience: Faculty Publications

Fully relativistic first-principles calculations of the Fe(001) surface demonstrate that resonant surface (interface) states may produce sizable tunneling anisotropic magnetoresistance in magnetic tunnel junctions with a single magnetic electrode. The effect is driven by the spin-orbit coupling. It shifts the resonant surface band via the Rashba effect when the magnetization direction changes. We find that spin-flip scattering at the interface is controlled not only by the strength of the spin-orbit coupling, but depends strongly on the intrinsic width of the resonant surface states.