Engineering Commons^™

Design, Implementation, And Evaluation Of A Shared-Memory Parellel Processing System (Smpps), Eric H. Staub

Theses

As technology reaches its limits of improvements in microprocessor processing speeds, scientists and engineers have to find viable solutions to meet ever-increasing demands for faster processing speed. One such solution is parallel processing. No longer does one have to wait on sequential operations. A specific task can be split in sub-tasks that can run simultaneously, thus reducing the overall execution time of the task.

The design and implementation of these systems is crucial to the effectiveness of parallel systems. A dual-processor SMPPS was designed and implemented in order to demonstrate how multiple processors are a viable solution to increasing the …

An Investigation Of Polyethylene Bearing Wear Of New Jersey Lcs Knee On Cobalt Chromium And Titanium Nitride Types, Lei Wang

Theses

The total knee replacement systems (TKRS) are used for the treatment of osteoarthritis and rheumatoid arthritis. Excessive wear can substantially shorten their life span.

Two tests were performed to examine the wear characteristics of tibial bearings used in TKRS. Each test consisted of six sets of Anterior/Posterior Glide Tibial Bearings each with a conical control arm. The tibial bearings were all made by UHMWPE. Three of these bearings were mounted onto a Co-Cr alloy tibial platform and Co-Cr alloy LCS® femoral component. Another three sets of bearings were mounted onto a TiN tibial platform and TiN LCS® femoral component. They …

Metrics For Estimating The Product Disassembly Effort, Pradeep Kumar Yedlarajaiah

Theses

The concepts of environmentally friendly manufacturing and ecological reuse of materials have resulted in an increase in the number of disposed products that are disassembled. Moreover, the imposition of EPA regulations is forcing companies to invest in methods for protecting the environrnent. The first strategy in this vein is material recycling. The issue of recycling became important because of the limited landfill space, diminishing natural resources, environmental pollution due to dumping of products containing hazardous materials. Likewise, it is projected that the cost of extracting materials from natural resources is going to be much more expensive when compared to reclaiming …

Evaluation Of Rotating Fluidized Bed As A Dry Coater, William Christopher Dunphy

Theses

Coating of particles is normally carried out with the use of environmentally unfriendly solvents. Development of dry coating methods is therefore quite important.

A Rotating Fluidized Bed was constructed, instrumented and verified as to operation. Twelve coating experiments were carried out with PMMA 200μm mean diameter as host and alumina 0.25μm primary particle size as guest with the RFB being operated in the fully fluidized range.

In all analyzed samples, coating was observed. Analysis was carried out on the qualitative basis by SEM and EDX.

Characterization Of Tantalum Coatings On Steel Substrates, Prabha Shivaramkrishnan

Theses

Sputtered tantalum can be used as an effective corrosion resistant barrier if the coating is continuous, free from defects and is adherent to the substrate it is intended to protect. For corrosion-applications 100% bcc phase tantalum is preferred. X-ray diffraction results indicate that sputtered tantalum deposits typically contain a mixture of bcc and beta phases. Depending on the deposition conditions the morphology of tantalum coatings as studied using scanning electron microscopes can vary from irregular, dendritic structure to a defined step type structure. A "cauliflower type" structure has also been observed. Extended x-ray absorption fine structure measurement was used to …

Room Temperature Fatique Response Of Γ-Tial To Impact Damage, Trevor S. Harding, J. Wayne Jones, P. S. Steif, T. M. Pollock

Materials Engineering

Gamma based titanium aluminides have received considerable attention recently as candidate materials in gas turbine applications, particularly low pressure turbine blades (1–3). Their low density and high specific stiffness, result in potentially significant weight savings in structures such as gas turbine engines if substituted for current materials. Two γ-TiAl microstructures are predominately identified in the literature: a lamellar microstructure consisting of alternating plates of γ and α₂, and a duplex microstructure consisting of equiaxed γ grains and lamellar colonies (3,4). Lamellar alloys generally exhibit better fracture toughness and fatigue crack growth resistance (5–7). Duplex alloys, on the other …

Jan 1999, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Museum Open House Officer Elections UN Museum

Emerald: A Low-Cost Spacecraft Mission For Validating Formation Flying Technologies, Robert J. Twiggs, Chris Kitts, Jon How

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs, Chris Kitts, and Jon How titled "EMERALD: A Low-Cost Spacecraft Mission for Validating Formation Flying Technologies" from January 19, 1999.

Band Gap Energy In Nanocrystalline Zro2:16%Y Thin Films, Igor Kosacki, Vladimir Petrovsky, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

The results of optical absorption measurements on nanocrystalline ZrO2:16%Y thin films are presented. Dense 0.7 μm thick films with 1-300 nm grain size have been obtained on sapphire substrate using a polymeric precursor spin coating technique. The relationship between the energy gap and microstructure of ZrO2:16%Y has been determined and discussed. The quantum confinement effect was observed at the grain size lower than 100 nm with the band gap energy shift of 0.25 eV when the microstructure was changed up to 1 nm. Some limitation of the model has been observed and discussed. The band gap energy of 5.62±0.05eV has …

Aviation Security: The Human Element In Human Factors, Ibpp Editor

International Bulletin of Political Psychology

This article describes aspects of social and political human functioning that are germane to security violations discovered by representatives of the Federal Aviation Agency (FAA) in tests at various United States (U.S.) airports. FAA reports on the violations were obtained by The New York Times through the U.S. Freedom of Information Act and discussed in the Times' January 11th Issue.

Method And Apparatus For Production Of Levulinic Acid Via Reactive Extrusion, Viswasrao Ghorpade, Milford Hanna

Industrial Agricultural Products Center: Publications and Information

The present invention relates to a continuous process for preparing levulinic acid from starch in a reactive extrusion process. In a preferred embodiment, the extrusion takes place in a twin-screw extruder having a plurality of temperature zones wherein the starch slurry is preconditioned, extruded, filter pressed, reboiled, vacuum distilled, condensed, centrifuged, whereby the waste effluent from the centrifugation is reprocessed upstream to the preconditioning stage.

Paint Gun Incorporating A Laser Device, Richard J. Klein, Douglas L. Sevey, Alireza Badakhshan, Ricky Jay Bauer

Patents (University of Northern Iowa)

A spray gun for applying a liquid spray coating, such as paint, to a surface incorporates a light source system for gauging the position of the spray gun relative to a worksurface in order to optimize application of the coating to the surface. The light source is preferably in the form of a laser which emits a pair of light beams toward the worksurface. The pair of light beams converge toward each other in a direction toward the surface, and the position of the beams on the surface is used by the operator to judge the distance of the spray …

Worn Tool Forces Based On Ploughing Stresses, Daniel Waldorf, Shiv G. Kapoor, Richard E. Devor

Industrial and Manufacturing Engineering

Recent work in modeling of the ploughing mechanism in basic metal machining may provide a means of estimating the additional forces to be expected when cutting with a worn tool. The results predict the rubbing stresses due to the finite radius of an unworn tool edge. Since an unworn tool can be thought of as a worn tool with a wear land width VB = 0, these stresses can make up part of a strategy for predicting the additional forces incurred by a worn tool. This paper develops a wear model by proposing a technique for utilizing the stresses predicted …

Managing District Data Needs – Narrowing In On A Moving Target, Charles M. Burt

BioResource and Agricultural Engineering

San Luis Water District, Panoche Water District, Delano-Earlimart Irrigation District (DEID), Westside Water District, Glide-Kanawha Water District (GKWD), and Central California Irrigation District (CCID) are blazing data management trails in the Mid-Pacific Region of the USBR. Ditchriders in these districts use or are beginning to use hand held data recorders (HHDR) to gather field information. The data management needs of these districts differ and as a result, the approach for each district differs. Further, each district is tackling portions of its data management needs in a stepwise fashion. The success of each step and the successes of other district approaches …

Acuta Enews January 1999, Vol.28, No. 1

ACUTA Newsletters

In This Issue

High Priorities for '99

Board Report

Making Choices: ATM vs. Gigabit Ethernet

Overheard on the Listserve: Is VoIP for Me?

DC at a Glance

Positions Available

Welcome New Members

Universal Translations Service

Use Telephone Wires To Create a Household Network

Information, Please

High Speed Networking

ACUTA Member Needs Assessment: Members are Highly Satisfied with ACUTA Services

Photoreflectance Investigations Of The Bowing Parameter In Algan Alloys Lattice-Matched To Gan, Tomasz J. Ochalski, Bernard Gil, Pierre Lefebvre, Nicolas Grandjean, Mathieu Leroux, Jean Massies, Shuji Nakamura, Hadis Morkoç

Electrical and Computer Engineering Publications

Room temperature photoreflectance investigations have been performed on a series of AlGaN layers grown both by metalorganic vapor phase epitaxy and molecular beam epitaxy on c-plane sapphire substrates. The aluminum composition was ranging between 0% and 20%, and was determined independently in the different growth laboratories, by various methods. It is found that within the experimental uncertainty, there is no detectable bowing parameter in these alloys. This contradicts some previous experimental investigations and confirms other ones.

Determination Of Particle Size Distributions From Acoustic Wave Propagation Measurements, Ashok S. Sangani, Peter D. M. Spelt, Michael A. Norato, Lawrence L. Tavlarides

Biomedical and Chemical Engineering - All Scholarship

The wave equations for the interior and exterior of the particles are ensemble averaged and combined with an analysis by Allegra and Hawley @J. Acoust. Soc. Am. 51, 1545 ~1972!# for the interaction of a single particle with the incident wave to determine the phase speed and attenuation of sound waves propagating through dilute slurries. The theory is shown to compare very well with the measured attenuation. The inverse problem, i.e., the problem of determining the particle size distribution given the attenuation as a function of frequency, is examined using regularization techniques that have been successful for bubbly liquids. It …

I-Line Exposure Capability For 6 Inch Wafers, Jerome Wandell

Journal of the Microelectronic Engineering Conference

The HIT Factory is currently in the development phase for a 6 inch sub-micron CMOS process. The addition of the Canon FPA-2000i1 stepper completes the necessary equipment required to perform a 6 inch photo process at HiT. The major focus of this project is to further the 6 inch photo process development, specifically to setup the exposure process for the first two levels (p-well and active) of the HIT test chip. TV pre-align mark number 2 and auto-align mark 20P-4F were added to all eleven levels of the HIT test chip layout around the originally designed pattern~ area. The revised …

Critical Dimension Analysis On The Rit Canon I-Line Stepper, Justin Novak

Journal of the Microelectronic Engineering Conference

This project involved the simulation and analysis of critical dimensions (CD) using the RIT Canon 2000i1 i-line stepper. This was accomplished by optimizing the stepper parameters for specific resist feature widths. There are many tools and methods that lithography engineers have at their disposal for use in optimizing current and future lithography processes. The focus-exposure (1?~E) matrix and resulting plot are integral parts of standard IC processing~ It is one of the most important plots used in lithography since it demonstrates how exposure and focus work together to affect critical dimension, sidewall angle, and resist thickness loss data. This data …

Amorphous Silicon For 157nm Lithography, Carlos Fonseca

Journal of the Microelectronic Engineering Conference

Amorphous silicon (a-Si) was investigated as a potential masking material at 157nm wavelength. Characterization of a-Si included film deposition on CaF2 (calcium fluoride) substrates through reactive sputtering, spectroscopic ellipsometry in the UV range, reflection and transmission at 157nm wavelength, and extraction of optical constants (n&k) with a commercial software package. Experimental results suggest that a-Si films deposited at RIT have similar optical constants as published values in the UV range. Simulation work suggests that a 50A silicon nitride film can be used as an anti-reflective layer to minimize reflections at the a-Si I air boundary. Consequently, silicon nitride films were …

Resist Characterization For 157nm Lithography, Christopher Bolton

Journal of the Microelectronic Engineering Conference

A resist characterization experiment was performed utilizing 157nm Vacuum Ultra-violet (VUV) Lithography. A number of older technology resists such as MXP8, APEX-E, and UVIII were placed in the beam path of a Lumonics Series 700 fluorine excimer laser and subjected to timed exposures on the tool. The features were then developed in a low normality CD26 developer and characterization curves for each of the resists were plotted. Through the experimentation it was found that each of the three resists investigated was able to clearly demonstrate imaging qualities at 157nm. The contrast curves of the MXP8 and APEX-E resist indicate that …

Oxidation Kinetics Of Nitrogen Implanted Silicon, Nathaniel E. Wescott

Journal of the Microelectronic Engineering Conference

Incorporation of nitrogen into the silicon lattice has been shown to severely retard the oxidation rate. The objective of this experiment was to determine a) whether it was a damage related issue and b) the kinetics. Equal doses of silicon were implanted along with the diatomic nitrogen (AMU 28) to determine whether it was a damage related issue. The added silicon did not hinder or benefit oxide growth. From this experiment, the oxidation rate of nitrogen implanted silicon can be best fit by the use of a linear model. Surface charge analysis indicated that flatband charge, interface trap density, and …

Plasma Induced Damage To Thin Gate Oxides, Dustin L. Winters

Journal of the Microelectronic Engineering Conference

Two mechanisms of plasma processing damage to thin gate oxide structures were studied. Thin 17.5 mu oxide on Si substrate structures were studied after direct exposure to a oxygen plasma environment with surface charge analysis and breakdown voltage measurements. A second antenna structure was used to study the charging effects of an oxygen plasma on 17.5 nm gate oxides through breakdown voltage measurements. A correlation was found between duration of plasma exposure and the extent of damage in terms of decreased dielectric strength and changes in oxide charge levels for both experiments.

Oxide Passivated Nanocrystalline Silicon Trap-Controlled Memory Devices, Burcay Gurcan

Journal of the Microelectronic Engineering Conference

An alternative to the single floating gate on a standard EEPROM device could be a continuous semi insulating layer in which the distribution of charge can be controlled. By partial oxidation of porous silicon, a new material named Oxide Passivated Nanocrystalline Silicon (OPNSi) is formed, which has embedded Si nanocrystals in a porous glass structure. With oxide barriers between silicon nanocrystals, carriers can be confined to the silicon crystallites or trapped at interface states on the surface of these nanocrystals. With the assistance of an electric field, carriers can undergo direct tunneling through the very thin barriers and alter the …

Integration Of Sige Resonant Interband Tunneling Diodes With Rit Cmos, Petya Vachranukunkiet

Journal of the Microelectronic Engineering Conference

This study investigates the integration of SiGe resonant interband tunneling diodes (RTD) with a standard silicon p-well CMOS process. It is feasible to build the RTD devices on the MOS source/drain regions if the RTD process did not degrade MOS devices. Besides, some etch selectivity issues need to be addressed. MOS transistors were subjected to the thermal cycling of the molecular beam epitaxial growth process and the rapid thermal anneal used in the fabrication of RTDs prior to contact formation. No destructive effects on the operation of NMOS and PMOS devices were observed. NMOS devices exhibited a positive shift of …

Development Of An Anisotropic, Highly Selective Tungsten Silicide Dry Etch Process, Thomas Schulte

Journal of the Microelectronic Engineering Conference

The development of an anisotopic Tungsten Suicide etch that will provide good selectivity to photoresist as well as an underlying oxide has been studied. It has been found that by reducing the amount of fluorine (SF6) in the system and increasing the chlorine concentration, slightly tapered sidewalls can be achieved without the use of a polymer forming gas. An optimum process was developed on an Applied Materials P-5000 MxP system. A condition of 10 sccm SF6, 40 sccm Cl2, 20 sccm 11e02 at 30 mTorr, and 400W presents slightly tapered sidewalls with within wafer uniformity of 4.85%. The selectivity of …

Electrolytic Plating Of Copper For Advanced Interconnects, Michael T. Myszka

Journal of the Microelectronic Engineering Conference

There is great interest in the semiconductor industry to move to copper for advanced interconnect processing. The purpose of this study was to develop an electroplating process so further studies in copper processing can be undertaken at R.LT. Electroplating was performed using the facilities available at the University of Rochester. This system utilizes a copper sulfate based electrolyte and an 8” wafer holder. In order to use the electroplating tool for four-inch wafers, a fixture was designed. Plating was performed on Si wafers coated with adhesion and seed layer of copper at varying current densities. Plated films were characterized for …

Pattern Density Effects On The Chemical Mechanical Planarization Of An Interlevel Polymer Dielectric, Teresa M. Evans

Journal of the Microelectronic Engineering Conference

Chemical Mechanical Planarization is quickly becoming a standard in microelectronical processing. CMP can decrease the depth of focus constraints in photolithography, resolve topography issues for multilevel interconnects, improve metal step coverage, and be used as an alternative etch process. The recent break-through in the copper damascene process has invoked a large number of studies focused on the planarization of oxides and metals. The research has proven beneficial for other applications where oxides are used as an interlevel dielectric material It has also shown the need for further studies in the polishing of other dielectric materials. The purpose of this experiment …

8 Bit Analog-To-Digital Converter Design And Simulation, Alberto J. Reyes

Journal of the Microelectronic Engineering Conference

The purpose of this study is to present and characterize an 8 bit AD converter implemented with flash architecture. Flash architecture provides with one of the fastest and easiest ways to convert analog input signals to digital outputs. Analog-to-digital conversion is the process in which a continuously varying analog signal is transformed into a multilevel digital signal. Analogue electrical waveforms are applied to the converter and are sampled at a fixed rate. Sample values are then expressed as a binary number consisting of 0’s and l’s. The resulting digital code can be used to encode digital audio, applications in video …

Fabrication And Development Of A Charge Injection Device Imager, Ivan Puchades

Journal of the Microelectronic Engineering Conference

As Rochester Institute of Technology (RH) brings into production i-line capabilities with a new Canon stepper, resolution beyond 2μm will be possible. The present project prepares one of RIT’s most novel and successful processes for this transition. The process for a Charge Injection Device Imager (CD)) has been entirely developed at RIT through the work and collaboration between the Imaging Science and Microelectronic Engineering Departments. After the initial success in the design and fabrication of 8X8 and 32X32 imager, a more challenging 54X40 process was developed employing 6-micron PMOS technology. The goal of this project is the successful …