Engineering Commons^™

Incorporating Computational Fluid Dynamics Into The Preliminary Design Cycle, Jonathan Knighton Shelley

Theses and Dissertations

Industry is constantly looking for ways to bring new or derivative products to market in the shortest amount of time for the least amount of money. To accomplish this, Industry has adopted Computer Aided Engineering (CAX) tools that perform structural, flow, manufacturing, and cost analysis. The way in which a company utilizes these CAX tools can determine the success of these new products. One of these tools that Industry often struggles with in the preliminary design of a product is Computational Fluid Dynamics (CFD). Some of the challenges presented by CFD are the time it takes to create a CAD …

The University Cubesat Initiative: It's Global Acceptance, Some Present Projects And Speculation As To It's Future, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "The University CubeSat Initiative: It's Global Acceptance, Some Present Projects and Speculation as to It's Future" from July 27, 2005.

High Temperature Heat Exchanger Project: Quarterly Progress Report April 1, 2005 Through June 30, 2005, Anthony Hechanova

Publications (NSTD)

Quarterly Collaboration Meeting. General Atomics hosted a UNLVRF HTHX Project quarterly meeting on June 5 in San Diego, California. The purpose of the meeting was to promote collaboration and communication among the UNLV Research Foundation partners. Collaborators had the opportunity to discuss their research program plan and update their progress. The next meeting will be in September in Berkeley hosted by UC Berkeley.

HTHX Computational Design (UNLV). Work on optimizing the ceramic offset strip in compact HTHX design through parametric studies was performed and completed. A simple single channel model was used to perform parametric studies on dimensions and flow …

The Impact Of Antenna And Rf System Characteristics On Mimo System Capacity, Matthew Leon Morris

Theses and Dissertations

The recent growth in demand for wireless services coupled with the limited spectrum available for these services has spawned new efforts to increase the spectral efficiency of wireless links. Recent research has shown that in multipath propagation environments, the spatial characteristics of the propagation channel can be exploited to increase spectral efficiency through the use of multiple antennas at the transmitting and receiving nodes. Such multiple-input multiple-output (MIMO) systems show promise for dramatic performance gains over their single-antenna counterparts. However, MIMO system performance is influenced by many different factors. Antenna array configuration directly contributes to MIMO system performance. The ability …

Real-Space Electron Transfer In Iii-Nitride Metal-Oxide-Semiconductor-Heterojunction Structures, S. Saygi, A. Koudymov, V. Adivarahan, J. Yang, Grigory Simin, M. Asif Khan, J. Deng, R. Gaska, M. S. Shur

Faculty Publications

The real-space transfer effect in a SiO₂∕AlGaN∕GaN metal-oxide-semiconductor heterostructure (MOSH) from the two-dimensional (2D) electron gas at the heterointerface to the oxide-semiconductor interface has been demonstrated and explained. The effect occurs at high positive gate bias and manifests itself as an additional step in the capacitance-voltage (C‐V) characteristic. The real-space transfer effect limits the achievable maximum 2D electron gas density in the device channel. We show that in MOSH structures the maximum electron gas density exceeds up to two times that at the equilibrium (zero bias) condition. Correspondingly, a significant increase in the maximum channel current (up to …

Stability Analysis For Forging Of Porous Bodies, Xuan Wang, Eugene Olevsky, Alain Molinari

Industrial and Manufacturing Engineering

The continuum theory of sintering is used for the analysis of the stability of forging of a cylindrical powder specimen. The constitutive properties of the powder material are assumed to follow a power-law creep relationship. Temperature-coupled linear non-uniform stability analyses are carried out. Stability maps are obtained for forging of copper powder components.

A Collision Detection Chip On Reconfigurable Hardware, Nuzhet Atay, John W. Lockwood, Burchan Bayazit

All Computer Science and Engineering Research

Collision detection algorithms check the intersection between two given surfaces or volumes. They are computationally-intensive and the capabilities of conventional processors limit their performance. Hardware acceleration of these algorithms can greatly benefit the systems that need collision detection to be performed in real-time. A Field Programmable Gate Array (FPGA) is a great platform to achieve such acceleration. An FPGA is a collection of digital gates which can be reprogrammed at run time, i.e., it can be used as a CPU that reconfigures itself for a given task. In this paper, we present an FPGA based collision detection chip. The chip …

Nesting Automated Design Modules In An Interconnected Framework, Jared Matthew Young

Theses and Dissertations

This thesis seeks to extend the PDG methodology by developing a generalized formal method for nesting PDGs in an interconnected system. A procedure for decomposing an individual PDG into reusable modules will be defined and a software architecture will be presented which takes advantage of these reusable modules. This method breaks the PDG structure into discrete elements known as PDG objects, PDG modules and PDG services. Each of these elements forms a distinct unit of reuse and each can be seen as a "little" PDG. Two different industrial implementations of this method are presented. These examples show that it is …

Reduced Complexity Detection Methods For Continuous Phase Modulation, Erik Samuel Perrins

Theses and Dissertations

Continuous phase modulation (CPM) is often plagued by high receiver complexity. One successful method of dealing with this is the well-known pulse amplitude modulation (PAM) representation of CPM, which was first proposed by Laurent. It is shown that the PAM representation also applies to multi-h CPM and ternary CPM, two previously unconsidered cases. In both cases it is shown that many PAM components may be required to exactly represent the signal. This is especially true of partial-response systems where the memory of the signal is long. Therefore, approximations are proposed which require only a limited number of terms. These extensions …

Theoretical Investigation Of Surface Roughness Scattering In Silicon Nanowire Transistors, Jing Wang, Eric Polizzi, Avik Ghosh, Supriyo Datta, Mark Lundstrom

Other Nanotechnology Publications

Using a full three-dimensional (3D), quantum transport simulator, we theoretically investigate the effects of surface roughness scattering (SRS) on the device characteristics of Si nanowire transistors (SNWTs). The microscopic structure of the Si/SiO2 interface roughness is directly treated by using a 3D finite element technique. The results show that (1) SRS reduces the electron density of states in the channel, which increases the SNWT threshold voltage, and (2) the SRS in SNWTs becomes less effective when fewer propagating modes are occupied, which implies that SRS is less important in small-diameter SNWTs with few modes conducting than in planar metal-oxide-semiconductor field-effect-transistors …

Sheep Updates 2005 - Part 2, Peter Tozer, Janette Drew, K. E. Kemper, M. L. Hebart, F. D. Brien, K. S. Jaensch, R. J. Grimson, D. H. Smith, A. M. M. Ramsay, J. S. Richards, K. D. Atkins, T. Thompson, W. K. Murray, J. R. L. Hall, Chris Carter, Peter Tozer, Mark Hyder, John Young, B. A. Mcgregor, Patricia Harper

Sheep Updates

This session covers seven papers from different authors: CONCURRENT SESSIONS - STRATEGIC MANAGEMENT 1.Finishing Pastoral Lambs, Peter Tozer, Patricia Harper, Janette Drew, Department of Agriculture Western Australia 2. Coating Improves Wool Quality under Mixed Farming Conditions, KE Kemper, ML Hebart, FD Brien, KS Grimson, DH Smith AMM Ramsay, South Australian Research and Development Institute 3. J. S. Richards, K.D. Atkins, T. Thompson, W. K. Murray, Australian Sheep Industry Co-operative Research Centre and NSW Department of Primary Industries, Orange Agricultural Institute, Forest Rd. Orange 4. Strategic Risk Management in the Sheep Industry, J.R.L. Hall, ICON Agriculture (JRL Hall & Co) 5. …

Integrating Animal Feeding Strategies Into Cnmp Processes: Role Of Updated Asae Standard D384.2, Richard K. Koelsch, W. Powers, A. L. Sutton

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

This paper introduces the new ASAE Standard D384.2, Manure Production and Characteristics. This new standard provides an equation-based approach that integrates dry matter and nutrient intake as well as animal performance into the final estimate of total solids, nitrogen, and phosphorus excretion for seven livestock and poultry species. The manure excretion estimates of the new standard are compared with the past ASAE standard as well as other commonly used reference values for three specie groups. Significant differences in excretion are common with the new standard compared to past standards. The paper also details examples of how common industry variations in …

Managing Phosphorus In Beef Feeding Operations, William F. Kissinger, Richard K. Koelsch, Galen E. Erickson, Terry J. Klopfenstein

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

A commercial feedlot study was conducted to determine manure nutrient flow in six feedlots representing 6,366 cattle. On average, cattle involved in this summary were yearlings (BW = 353 kg) and gained 183 kg over 123 d. It was calculated that 11.5% of the feed nitrogen and 16.9% of the feed phosphorus was retained by the animal with the remaining nutrients excreted. On average, 25.6 kg of N and 4.1 kg of P (DM basis) were excreted per fed beef animal. On average, 887 kg total manure (solids and water) were removed per finished animal (7.2 kg/animal/d) averaging 73% total …

A New Application For Fine Ground Rubber In The Control Of Odors From Livestock Manure Storage Structures, Lakshmi Koppolu, Richard K. Koelsch, Dennis D. Schulte, Crystal Powers, Dwaine Bundy

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

The purpose of this project was to quantify the odor and gas emission benefits of a fine ground rubber cover on laboratory scale manure storage units and to evaluate the ability of a fine ground rubber cover applied to a commercial swine manure storage unit to remain intact and functional over an extended period of time. A three-inch cover of fine ground rubber reduced odors by 77 to 99 percent from the manure storage tanks over a six-week period. However, consistent reductions of NH₃ emissions were not observed and H₂S emissions from all manure storage treatments were …

Ua1b2/1/5 Oral History, Paula Trafton, Charles Anderson

WKU Administration Documents

Interview conducted by Paula Trafton with Charles Anderson, retired Vice President for Information Technology.

Biofilm Removal Using Bubbles And Sound, Michael R. Parini

Theses and Dissertations

Bacteria in biofilms adhere well to surfaces and are quite difficult to remove. Oral plaque is one example of a biofilm. Many researchers have studied ways to remove plaque and bacteria from surfaces. It has been found that the passage of a bubble across a surface to which bacteria has adhered can remove the bacteria from the surface. Biofilms of Streptococcus mutans were grown on glass coverslips as a simple model for oral plaque. The coverslips were mounted in a Plexiglas chamber filled with artificial saliva. A bubble stream was directed at the mounted biofilm. The velocity, gas fraction, median …

Full-Scale Lateral Load Test Of A 3x5 Pile Group In Sand, James Matthew Walsh

Theses and Dissertations

Although it is well established that spacing of piles within a pile group influences the lateral load resistance of that group, additional research is needed to better understand trends for large pile groups (greater than three rows) and for groups in sand. A 15-pile group in a 3x5 configuration situated in sand was laterally loaded and data were collected to derive p-multipliers. A single pile separate from the 15-pile group was loaded for comparison. Results were compared to those of a similar test in clays. The load resisted by the single pile was greater than the average load resisted by …

Experimental And Numerical Investigation Of Tool Heating During Friction Stir Welding, Joshua L. Covington

Theses and Dissertations

The heat input to the tool has been investigated for friction stir welding (FSW) of aluminum alloy AL 7075-T7351 over a wide range of process operating parameters using a combined experimental/numerical approach. In a statistical Design of Experiments fashion, 54 experimental welds (bead-on-plate) were performed at 27 different parameter combinations. Measured outputs during each of the welds included forces in all three coordinate directions and internal temperature of the rotating tool at three locations near the tool/workpiece interface. The heat input to the tool was also identified for each weld using infrared imaging temperature measurement techniques and the portion of …

Annual Exceedance Probability Analysis, Masako Amai Gardner

Theses and Dissertations

Annual Exceedance Probability (AEP) is the method used by U.S. Army Corps of Engineers (USACE) to determine the probability of flooding caused by the failure of a levee or other flood control structure. This method shows the probability of flooding only at one particular location at a time. In order to overcome the limitation of AEP, a new method of studying flood probability, called an AEP map, was presented. By using hydrologic and hydraulic modeling software, an AEP map can be created to determine and visualize the spatial distribution of the probability of flooding. An AEP map represents a continuous …

Visualizing And Interacting With Externally Coupled Engineering Analysis Results, Paul Frederick Nelson

Theses and Dissertations

Visualizing and interacting with engineering analysis results can provide valuable insights into a system's performance and aid in engineering decision-making. Currently, the majority of analysis codes are developed as isolated solutions focusing only on the most prominent physical influence to a system, such as thermal, structural, fluid, etc. Frequently, more than one of these physical influences combined to force engineers to evaluate complex, coupled systems. Coupled analysis codes are becoming more common place tools for engineers demanding high fidelity simulations of complex systems. External code coupling solutions are emerging to permit generic coupling of separate, world class CAE solvers thus …

Development Of A Weatherproof Windscreen For A Microphone Array, Jeffrey R. Hill

Theses and Dissertations

Microphone windscreens are typically used to reduce the noise associated with wind flowing over a microphone diaphragm by reducing the velocity of the airflow. While most windscreens are effective at reducing this noise, they do not protect the microphone from many natural elements, such as moisture, sand, and other small particles. The focus of this research was to design a windscreen that protects an array of five microphones located around a 4.5-inch diameter cylinder from these natural elements. The design goals were to have a wind noise attenuation of at least 8 dB, an insertion loss of less than 1 …

An Energy-Efficient Media Access Control Protocol For Chain-Type Wireless Sensor Networks, Yu Wang, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

We present in this paper an energy efficient media access control (MAC) protocol for chain-type wireless sensor networks. The chain-type sensor networks are fundamentally different from traditional sensor networks in that the sensor nodes in this class of networks are deployed along narrow and elongated geographical areas and form a chain-type topology. Recently, we have successfully developed hierarchical network architecture, sensor deployment strategy, and corresponding network initialization and operation protocols for this class of sensor networks. In this paper, we present a novel TDMA scheduling protocol that takes full advantages of the available channel reuse inherent in the chain-type sensor …

Application-Specific Routing Scheme For Indoor Wireless Localization Systems, Tamas Kasza, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

The proposed research focuses on the communication in an RF-based indoor wireless localization system. In such a system, wireless badges attached to people or devices report positions to wireless gateway units. Badges have very limited communication, energy, as well as processing capabilities. However, gateways are significantly less constrained by battery than the badges. Wireless gateway units route collected badge information hop-by-hop towards one central unit of the system. We assume that each gateway unit has one transceiver antenna and is able to determine its own relative position in the system. The goal of this research is to develop an application-specific …

System And Device For Characterizing Shape Memory Alloy Wires, Robert Ryan Vallance, Bruce L. Walcott, James E. Lumpp, Sumanth Chikkamaranahalli, Osamah A. Rawashdeh, Eric Wolsing

Mechanical Engineering Faculty Patents

Instruments and methods for measuring a property of a shape memory alloy are provided. The instrument includes a base plate, a non-contact movable mass, a force gauge, an actuator, a biasing spring, a heater for heating the shape memory alloy, and a non-contact displacement detector. The biasing spring and the shape memory alloy are disposed whereby a force applied thereby is applied substantially through a center of stiffness of the movable mass. The displacement detector measures a displacement of the movable mass in a colinear direction with a direction of movement of the movable mass and with a direction of …

Establishing Public Confidence In The Viability Of Fingerprint Biometric Technology, Nathan Alan Green

Theses and Dissertations

The most common personal authentication techniques used for identity management employ a secret PIN or password that must be remembered. The challenge, for a given user, is that a multitude of such codes must be recalled over the course of the day for transactions involving distinct computer applications. Password mania prevails. Fingerprint biometric technology is an ideal alternate solution to this password recall problem. In spite of their availability for nearly thirty years, fingerprint biometric systems still remain uncommon in public sectors of industry such as education, government, and technology. Technology has improved sufficiently that false acceptance and rejection rates …

Use Of Positron Annihilation Spectroscopy For Stress-Strain Measurements: Quarterly Progress Report (March – May 2005), Ajit K. Roy

Transmutation Sciences Materials (TRP)

Accomplishments:

● Analyses of defects (dislocations) in martensitic Alloy EP-823, cold-reduced to different levels, have been performed by using transmission electron microscopy. The dislocation density has been related to the degree of cold-reduction and residual stress in terms of a line-shape parameter determined by the positron annihilation spectroscopy (PAS).

● Additional PAS measurements are ongoing on tensile, welded and cold-worked specimens of Alloys EP-823 and HT-9 at the Idaho Accelerator Center of ISU. Both Subhra and Silpa are involved in these measurements.

● Silpa is performing neutron diffraction (ND) measurements at the Atomic Energy of Canada Limited (AECL), Chalk River …

Integrating Value Stream Mapping And Simulation, Michelle E. Scullin

Theses and Dissertations

An important principle in Lean manufacturing, value stream mapping (VSM) can be helpful in understanding how process flow and information flow affect each other. A VSM is a static picture of a process that allows the user to see where value is added into the value stream. Simulation is used to evaluate the behavioral issues of processes. In a manufacturing realm this means simulation shows how each operation affects other operations so determinations can be made about where bottlenecks or other problems exist in the process. Theoretically, the integration of VSM and Simulation can aide in process improvement by showing …

Ortho-Planar Mechanisms For Microelectromechanical Systems, Craig P. Lusk

Theses and Dissertations

A method for representing the design space of ortho-planar mechanisms has been developed. The method is based on the Theorem of Equality of Orientation Set Measures (TEOSM) which allows mechanisms to be represented by points in an abstract space. The method is first developed for single loop planar folded mechanisms with revolute joints, and later extended to mechanisms with prismatic joints and to spherical folded mechanisms. Functions which assign a value to each point in design space can be used to describe classes of mechanisms and evaluate their utility for MEMS design. Additionally, this work introduces the use of spherical …

Sub-Surface Corrosion Research On Rock Bolt System, Perforated Ss Sheets And Steel Sets For The Yucca Mountain Repository — Quarterly Technical Report No. 4, Dhanesh Chandra, Jaak J.K. Daemen

Publications (YM)

This report encompasses the work done for this third quarter, 2005, in accordance to cooperative agreement of University of Nevada system for the Task 019 “Subsurface Corrosion Research on Rock Bolt System, Perforated SS Sheets and Steel Sets for the Yucca Mountain Repository”, the overall objective of which is to conduct corrosion research and predict the durability of rock-bolts and other underground metallic roof supports. We have started oxidation tests using Thermogravimetric Analyzer (TGA), and Potentiodynamic tests to determine the corrosion rates of rock bolts, other support materials including bench mark materials. In this quarter, we have also performed hydrogen …

Vision-Based Target Localization From A Small, Fixed-Wing Unmanned Air Vehicle, Joshua D. Redding

Theses and Dissertations

Unmanned air vehicles (UAVs) are attracting increased attention as their envelope of suitable tasks expands to include activities such as perimeter tracking, search and rescue assistance, surveillance and reconnaissance. The simplified goal of many of these tasks is to image an object for tracking or information-gathering purposes. The ability to determine the inertial location of a visible, ground-based object without requiring a priori knowledge of its exact location would therefore prove beneficial. This thesis discusses a method of localizing a ground-based object when imaged from a fixed-wing UAV. Using the target's pixel location in an image, with measurements of UAV …