Engineering Commons^™

41st Conference On Senior Engineering Design Projects, College Of Engineering And Applied Sciences

Senior Engineering Design Conference

The 41st Conference on Senior Engineering Design Projects was held on December 4, 2007 at the College of Engineering and applied Sciences on the Parkview Campus of Western Michigan University. The college sponsors the conference to showcase the work of its graduating seniors, who are required to complete a capstone project that puts into practice what they have learned. Many of the projects are sponsored by business and industry.

Closed-Form Derivations Of Isi And Mui For Time-Reversed Ultra Wideband, K. Popovski, Beata J. Wysocki, Tadeusz Wysocki

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Through transmitter pre-filtering, a time reversed UWB system is capable if harnessing a multipath channel to achieve temporal and spatial focusing. Unfortunately, large RMS channel delay spread leads to significant intersymbol and multiuser interference. This paper presents closed-form expressions for self and multi-user interference for a UWB system utilizing a time-reversed approach. The influence of user multiplexing codes is taken to account through incorporation of a ‘separation probability’, which characterizes a family of hopping sequences. The standardized IEEE 802.15.3a channel model is applied, and the derived performances are compared with that of a simulated time hopped time-reversed UWB system.

Scalability Of Manet Routing Protocols For Heterogeneous And Homogenous Networks, Huda Al Amri, Mehran Abolhasan, Tadeusz Wysocki

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

In Mobile Ad hoc Network (MANET), mobility, traffic and node density are main network conditions that significantly affect the performance of routing protocols. Much of the previous researches in MANET routing have focused on developing strategies, which suit one specific networking scenario. Therefore, there is no existing protocol that can work well in all different networking scenarios. This paper reviews characteristics of each different classes of routing protocols. Moreover, most of current routing protocols assume homogeneous networking conditions where all nodes have the same capabilities and resources. Although homogenous networks are easy to model and analysis, they exhibits poor scalability …

Sold Downstream: Free Speech, Fair Use, And Anti-Circumvention Law, R. Terry Parker

The University of New Hampshire Law Review

[Excerpt] “Here’s a hypo. Living in Asia, I purchased a shameful amount of music and movies, all legit purchases through reputable stores, HMV and Tower Records, but little of which will get reissued. I wanted to preserve my collection but software in the discs prevented me from ripping backup copies to my computer. Lacking the technological savvy to get around this software myself, I purchased and used a product to help me circumvent these controls. Discuss.

Courts agree that copying the music and movies here is infringement but that fair use may provide a defense. However, courts do not agree …

Synthesis, Structure And Characterization Of Silver Doped Diamond Like Carbon Thin Films, Pankaj Jyoti Hazarika

Material Science and Engineering Theses - Archive

Diamond like carbon (DLC) films have gained grounds in the biomedical field as an inert, biocompatible, low friction and wear resistant coating and are widely used in heart valves, coronary artery stents, dental implants, knee prosthesis and other vascular devices. In addition, Ag nanoparticles/films can prevent the formation of biofilm on biomedical implants by degrading the metabolic activities like permeability and respiration and also impair DNA replicability. Thus, Ag-doped DLC (Ag-DLC) can serve as a multifunctional bio coating combining desirable antibacterial and physical/ mechanical characteristics. In the present study, Ag-DLC films were synthesized utilizing a hybrid Plasma CVD and Magnetron …

Synthesis And Characterization Of Ferromagnetic Nanoparticles, Kazuaki Yano

Material Science and Engineering Theses - Archive

Ferromagnetic nanoparticles and their bimagnetic nanoparticles with uniform size distribution have drawn great attention in the past decades because of their unique magnetic properties and potential applications in high density recording media, exchange-spring permanent magnets and biotechnology. In this thesis, synthesis and characterization of ferromagnetic nanoparticles (FePt, Sm-Co system) and bimagnetic nanoparticles (FePt/Fe3O4, FePt/Au) are reported. FePt nanoparticles with different sizes and compositions were successfully synthesized via chemical synthesis. FePt particle size was tuned to a range of from 3 nm to 8 nm with 1 nm accuracy by changing the surfactant to Pt precursor ratio. By optimizing the amount …

On The Near Field Mean Flow Structure Of Transverse Jets Issuing Into A Supersonic Freestream, Dean Anthony Dickmann

Mechanical and Aerospace Engineering Dissertations - Archive

The near field mean flow structure of transverse jets issuing from a surface into supersonic crossflow is examined using numerical methods and separation topology. The Navier-Stokes solver Falcon, developed at Lockheed Martin, was used to simulate the interaction between the jet and freestream over a flat plate and a generic missile body. The near field flow structure included a l bow shock upstream of the jet interacting with the approaching boundary layer that forms a pair of horseshoe vortices while another l- structure closer to the jet formed a second pair of horseshoe vortices. As the jet was turned downstream …

Methodologies For Automated Microassembly, Mohammad A. Mayyas

Mechanical and Aerospace Engineering Dissertations - Archive

The development of micromachining technologies has provided wide applications in micro sensing and actuation. However, most of the demonstrated devices are selectively constructed by fabrication processes that are limited to complexity, configuration, dimension, and material variation. The monolithic fabrication has limitations and does not allow the inclusion of multiple components of incompatible processes. Therefore, the construction of 3D microstructures by heterogeneous microassembly is an alternate manufacturing route. In deterministic, monitored or controlled microassembly there has been considerable research in developing, analyzing and applying distributed algorithms for sensor and sensorless based assembly processes. Meso-scale teleoperated work-cells supported by Nano manipulators have …

Thermal Enhancement Of Stacked Dice Replacing Wire Bonds With Through Silicon Vias At Location Of Die Pads, Venkata Chepuri Krishna Teja

Mechanical and Aerospace Engineering Theses - Archive

Through Silicon vias can offer quick time to market of circuits designed in a modular manner and can also be used to customize the product according to the needs of the customers. This gives a way to avoid both excess inventory risks and larger footprints. A through silicon via could be described as, a vertical component through which a backside interconnect for a pair of bonded wafers forming a wafer stack is ultimately cut into a number of stacked dice. Various embodiments have been patented [1, 2] but implementation of these architectures can be inhibited based on thermal, mechanical and …

Numerical Simulation Of Magnetohydrodynamics, Takahiro Sonoda

Mechanical and Aerospace Engineering Theses - Archive

Use of electromagnetic fields has been shown to be an effective way to control the behavior of electrically conducting fluids. Specifically, the modification of the boundary layer profile with electromagnetic fields can yield performance improvements such as reduced drag and improved heat transfer. Though this approach has been demonstrated computationally and experimentally with conducting liquids (i.e. seawater), application to aerodynamic devices operating in air has not seen the same success. Through the use of numerical simulation and eventually optimization, we hope to develop efficient designs that are effective for boundary layer control for low temperature conducting gases (non-thermal plasmas). The …

An Experimental Study On Thermal Bonding Effects Of Pmma Based Micro-Devices Using Hot Embossing, Varun Sood

Mechanical and Aerospace Engineering Theses - Archive

Basic configuration and functioning of various subsystems of a developed HEMM system for thermal bonding are discussed. The bond strength and micro channel geometry degradations dependence on controlled process parameters in thermal bonding using hot embossing has been investigated. The process parameters examined were bonding temperature, bonding or applied load and holding time. Polymeric substrates with different feature dimensions and thickness were embossed and bonded using hot embossing technology. The feature dimensions before and after bonding were examined to assess the geometry changes as functions of the bonding process. This assessment could provide guidance during the design phase of micro-fluidic …

Derivation Of The Dynamics Equations For Receiver Aircraft In Aerial Refueling, Jayme Lynn Waishek

Mechanical and Aerospace Engineering Theses - Archive

This thesis describes the derivation of a new set of nonlinear, 6--DOF equations of motion of a receiver aircraft undergoing an aerial refueling, including the effect of time-varying mass and inertia properties associated with the fuel transfer and the tanker's vortex induced wind effect. Since the center of mass of the receiver is time--varying during the fuel transfer, the equations are written in a reference frame that is geometrically fixed in the aircraft. Due to the fact that aerial refueling simulation and control deal with the position and orientation of the receiver relative to the tanker, the equations of motion …

Trends Of Vehicular Emissions For Clean Air Associates Precombustion Retrofit Device, Jaya Vani Nagireddi

Civil Engineering Theses - Archive

The research study objective was to find if there was any reduction in onboard exhaust emissions from a light duty passenger car (2007 Dodge Charger) with a Clean Air Catalytic Converter manufactured by Clean Air Associates, Inc. The research was conducted by the Civil and Environmental Engineering Department, University of Texas at Arlington as part of the North Central Texas Council of Governments Aftermarket Technology and Fuel Additive Research Program. Initially, emissions of pollutants were measured without the Clean Air Associates' retrofit device, called Baseline testing. A Horiba OBS-1300 On-Board System measured concentrations of the pollutants NOx, CO, CO2 and …

Modeling Unsaturated Soil Response Under Suction-Controlled Multi-Axial Stress States, Arthit Laikram

Civil Engineering Dissertations - Archive

In this research work, a novel suction-controlled true triaxial testing apparatus has been developed to test 3-in (7.5-cm) side, cubical specimens of unsaturated soil under controlled-suction states for a wide range of stress paths that are not easily achievable in a conventional cylindrical apparatus. The equipment is a mixed-boundary type of device, with the specimen seated on top of a high-air-entry ceramic disk and between five flexible (latex) membranes on the remaining sides of the cube. The new cell is an upgraded, more elaborate version of the one previously reported by Hoyos (1998), featuring two independent pore-air and pore-water pressure …

Suppressing Delta-I Noise In Mcml Circuits In Mixed Signal Environment, Ritesh Jayant Mehta

Electrical Engineering Theses - Archive

This work addresses the problem of simultaneous switching noise (SSN) in mixed signal environment. It is shown that the Metal Oxide Semiconductor Current Mode Logic (MCML) can be used to minimize the SSN. In short channel devices, Drain Induced Barrier Lowering (DIBL) effect causes the current mismatch problem. It is seen that this current mismatch problem aggravates SSN. Basic logic gates were designed using MCML topology at 5 Gbps. Parasitic model was introduced at power supply lines and substrate to study the behaviour of these logic gates in the presence of parasitics. Interpolation type delay cells were used to suppress …

What Is Rcu, Fundamentally?, Paul E. Mckenney, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Read-copy update (RCU) is a synchronization mechanism that was added to the Linux kernel in October of 2002. RCU achieves scalability improvements by allowing reads to occur concurrently with updates. In contrast with conventional locking primitives that ensure mutual exclusion among concurrent threads regardless of whether they be readers or updaters, or with reader-writer locks that allow concurrent reads but not in the presence of updates, RCU supports concurrency between a single updater and multiple readers. RCU ensures that reads are coherent by maintaining multiple versions of objects and ensuring that they are not freed up until all pre-existing read-side …

Improved Covariance Model Parameter Estimation Using Rna Thermodynamic Properties, Jennifer A. Smith, Kay C. Wiese

Electrical and Computer Engineering Faculty Publications and Presentations

Covariance models are a powerful description of non-coding RNA (ncRNA) families that can be used to search nucleotide databases for new members of these ncRNA families. Currently, estimation of the parameters of a covariance model (state transition and emission scores) is based only on the observed frequencies of mutations, insertions, and deletions in known ncRNA sequences. For families with very few known members, this can result in rather uninformative models where the consensus sequence has a good score and most deviations from consensus have a fairly uniform poor score. It is proposed here to combine the traditional observed-frequency information with …

A Cfd Investigation Of Axisymmetric Microthruster Nozzles For Use On Nano-Satellites, Michael R. O'Gara

Master's Theses - Daytona Beach

The performance of microthruster nozzles (^ 0.1 N thrust) depending on nozzle contour, propellant and surroundings, destined for use in nanosatellite missions, is investigated via a numerical approach using the Wind-US flow solver. An experimental apparatus designed to measure microthruster performance in atmospheric or vacuum conditions used to aid numerical simulations is also presented. Comparing the numerical and experimental results show an approximate 25% drop in efficiency for unknown reasons. An evaluation of favorable nozzle contours suggested by previous researchers is conducted, and the results demonstrate the need for a more rigorous treatment of the nozzle flow at the exit …

Stress Distribution And Strength Prediction Of Composite Laminates With Multiple Holes, Brian Esp

Mechanical and Aerospace Engineering Dissertations - Archive

The major purpose of this study was to investigate failure of composite laminates with multiple unloaded holes in close proximity. The least square boundary collocation method for anisotropic materials was utilized to determine the state of stress. The approach utilized collocation on both the internal and external boundaries, making it relatively easy to implement. The method compared favorably to both published and finite element solutions. A failure prediction approach for an infinite, symmetric and balanced laminate, with two holes in close proximity was presented. The baseline material for consideration was IM7/977-3, a carbon fiber/epoxy lamina. The failure prediction method was …

An Analytical And Numerical Model For Design Of Non- Uniformly Powered Silicon Chips Based On Both Thermal And Device Clock Performance, Abhihit D. Kaisare

Mechanical and Aerospace Engineering Dissertations - Archive

Silicon chips continue to grow in capabilities, complexity and performance. Silicon chips typically integrate functional components such as logic and level two (L2) cache memory in their architecture. This functional integration of logic and memory results in improved performance of the chip. However, the integration also introduces a layer of complexity in the thermal design and management of silicon chips. As a direct result of functional integration, the power map on a silicon chip is typically highly non-uniform and the assumption of a uniform heat flux across the chip surface has been shown to be invalid post Pentium II architecture. …

Thermal Stresses Of Composite Beams With Rectangular And Tubular Cross-Sections, Chia-Wei Su

Mechanical and Aerospace Engineering Theses - Archive

Closed-form analytical solutions for laminated composite beams with tubular and rectangular cross-sections are developed for evaluating the thermal induced stresses. The derivations are based on modified lamination theory and parallel axis theorem. The present approach includes variation of ply stiffness along the contour of the cross-section. The interlaminar shear stress of cantilever composite beam with rectangular cross-section under a transverse load is analytically proved to be independent of temperature change in uniform temperature environment. Three-dimensional finite element models for computing thermal stresses of both cross-sections are developed using commercial software package ANSYS 10. The results obtained from analytical solutions give …

Surface Patterning Of Biodegradable Polymer In Tissue Engineering By Applying Photolithography, Lee-Chun Su

Material Science and Engineering Theses - Archive

The prevalence of cardiovascular disease and inherent problems with current surgical therapies has prompted major efforts in the field of vascular tissue engineering. While there have been significant advances towards creating functional blood vessel substitutes, the fabrication of a vascular graft with mechanical, structural and functional properties similar to native vessels has not yet been achieved. We have presented an observation of a new biodegradable polymer utilized on the research of tissue engineering. Our idea was to create a structure to imitate blood vessel muscles in vitro and also to guide the cells when they start spreading and trying to …

Thermally Activated Sulfurization Scheme For Cuins2 Solar Cells, Karan Agrawal

Material Science and Engineering Theses - Archive

Chalcopyrite Solar Cells are now being fabricated on flexible (polymer) substrates. However, CuInS2 solar cells have not been fabricated on the polymer substrates on the commercial scale due the sulfurization temperature which limits the use of polymer substrates during fabrication. To overcome this problem a thermally activated sulfurization process for the manufacture of CuInS2 solar cells from the Cu-In bilayers is described in this work. This sulfurization process can be employed for lower temperature for the formation of the absorber layer. For the sulfurization, the Cu-In bilayer with different compositions is prepared by thermal evaporation in which the In-rich film …

Ductile Lightweight Concrete For Lightweight Structural Application, Ake Piyamaikongdech

Civil Engineering Theses - Archive

This study developed a ductile concrete for precast wall systems which are capable of resisting high wind in excess of 500 mph. The developed concrete mix design consists of sand, cement, glass fiber, and a foaming agent to produce lightweight concrete in the range of 87 pcf (1392 kg/m3) to 90 pcf (1440 kg/m3). A comprehensive testing program for evaluation of the developed concrete material was undertaken. The mix designs were prepared both in the laboratory and in the mix truck with drum capacity of 27 ft3 (0.77 m3), and 177.6 ft3 (5 m3), respectively. The large concrete batches using …

Evaluation Of Robocode As A Teaching Tool For Computer Programming, Arnold Hensman

Conference Papers

Robocode began as an educational tool to aid in learning Java programming. It has since evolved into something of a phenomenon, as the prospect of creating simple to complex virtual tanks appears to pose an attractive challenge to both novice and expert programmers alike. What started out as a teaching tool has grown into a worldwide network of competitors, all keen to prove that their ‘bot’ stands out from the crowd. Competitions are well organised and many Robocode events are a PR dream for the computing companies that sponsor them. Without a doubt, this easy to use application has sparked …

A Computational Method For Flow Separation Detection And Control For Axial Compressor Airfoils, Chang Jun Meang

Master's Theses - Daytona Beach

Conducting full annulus experiments on multistage compressors is costly and time consuming due to the complexity of the experimental processes. To reduce complexity, Computational Fluid Dynamics (CFD) methods are applied to turbomachinery and other applications in recent analysis of such cases. CFD methods are widely used within the aerospace industry and are increasingly demonstrating their reliability. For axial compressors, it is known that highly staggered compressor stators will increase the aerodynamic loading on the stator, which directly relates to the compressor stall and efficiency. In this work, compressor stators stagger angle is increased 4 ° to induce separation on the …

Prediction Of Tensile Strength For Sandwich Injection Molded Short-Glass-Fiber Reinforced Thermoplastics, S Patcharaphun, G Mennig

Journal of Metals, Materials and Minerals

This present paper provides a modified rule-of-mixtures relationship which allows for the calculation of ultimate tensile strength (UTS) as a function of the area fraction between skin and core layers. The effects of fiber length and fiber orientation within the skin and core layers on the tensile strength of conventional and sandwich injection molded short-glass-fiber reinforced polypropylene have been studied in detail. The present theory is then applied to existing experimental results and the agreement is found to be satisfactory

Ferroelectric Glass-Ceramic Sintering Aid For Lead Titanate Ceramics, P Sooksaen, I M. Reaney, D C. Sinclair

Journal of Metals, Materials and Minerals

Silicate-based glass that devitrifies on heating to form ferroelectric lead titanate has been developed. The potential for use as sintering aid in PbO-based electroceramics has been evaluated by studying the densification of PbTiO3 (PT) with increasing wt% addition of glass powder. As the wt% glass content increased, the density increased, the maximum and room temperature relative permittivity decreased and there was also a decrease in Tc and the c/a ratio. The decrease in Tc is believed to be due to increased clamping from neighbouring grains as the density of the PT increases. The decrease in maximum and room temperature relative …

Surface Modification Of Microfluidic Devices, P Kumlangdudsana, S T. Dubas, L Dubas

Journal of Metals, Materials and Minerals

Microfluidic is a multidisciplinary which encompasses the fields of physics, chemistry, nanotechnology, engineering, and biotechnology. It has been developed extensively for many applications such as handling biological entities such as DNA separation, immunoassay, cell sorting, biosensors, and enzymatic assays due to the potential offered by miniaturizing, high throughput of analysis, low cost of fabrication, multiplex functionality and portability. The surface modification of microfluidic devices has also been a major focus in research to help to enhance their efficiency. There is a variety of surface modification methods and in this paper we reviews and presents an overview of the surface modification …

Localization In Noisy Environment Using Extended Kalman Filter, Aneeket Suresh Patkar

Electrical Engineering Theses - Archive

Localization is an important aspect of Wireless Sensor Networks. Information regarding the position of the sensor nodes is not always known. Without the position information of the sensors, the data reported by the sensors is of little use. Various approaches have been used to perform localization using some information about the sensor node. Potential field approach for localization, using distance information has been successfully tested with satisfactory results. However in case of noisy environment, the range measurements have greater inaccuracy. In such cases, localization using the above algorithm can provide some inaccuracy. To rectify such erroneous localization situations, Extended Kalman …