Engineering Commons^™

Analysis Of Indentation Loading Of Cortical Bone Using Acoustic Emission Techniques, Ashkan Safari, Ger Reilly, Brendan Mccormack

Conference Papers

In this study, we recorded the number of Acoustic emission (AE) hits and related AE energy during indentation fracture of cortical bone using a PAC PCI-2 card and pico sensor. A threshold value of 43dB was used to filter premature trigger due to background noise. Registered AE hits had more than one count (threshold crossing). Amplifier gain was set at 40dB with a (0.1-1) MHz band pass filter. 8mm cubes of cortical bones were indented in the longitudinal direction at constant crosshead speed of 1 mm min-1 using a large 2D, 50˚ wedge indenter. We hypothesised that signals occurring as …

Injection-Locking In Fabry-Perot Quantum-Well Lasers, Xiaomin Jin, Shun-Lien Chuang

Electrical Engineering

No abstract provided.

Experimental Study Of The Solids Velocity Field In Gas-Solid Risers, Satish Bhusarapu, Muthanna H. Al-Dahhan, Milorad P. Duduković, Steven Trujillo, Timothy J. O'Hern

Chemical and Biochemical Engineering Faculty Research & Creative Works

Solids Flow Dynamics in Gas-Solid Risers is Inherently Complex. Model Refinement through Experimental Validation Requires the Acquisition of Detailed Nonintrusive Measurements. in This Study, Noninvasive Computer-Automated Radioactive Particle Tracking (CARPT) is Employed to Visualize and Quantify in a Three-Dimensional Domain the Solids Dynamics and Mixing in Gas-Solid Risers. This Technique Has the Added Advantage that, along with the Derived Eulerian Solids Flow Field (Time-Average Velocity Map and Various Turbulence Parameters Such as the Reynolds Stresses, Turbulent Kinetic Energy), It Also Provides Directly the Lagrangian Description of the Solids Motion. the Solids Velocity Field Data Are Obtained in Two Different Risers …

College Of Engineering Senior Design Competition Fall 2005, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps to focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects …

Dynamic Aeroelastic Analysis Of Wing/Store Configurations, Gregory H. Parker

Theses and Dissertations

Limit-cycle oscillation, or LCO, is an aeroelastic phenomenon characterized by limited amplitude, self-sustaining oscillations produced by fluid-structure interactions. In order to study this phenomenon, code was developed to interface a modal structural model with a commercial computational fluid dynamics program. LCO was simulated for a rectangular wing, referred to as the Goland⁺ wing. It was determined that the aerodynamic nonlinearity responsible for LCO in the Goland+ wing was the combination of strong trailing-edge and lambda shocks which periodically appear and disappear. This mechanism limited the flow of energy into the structure which quenched the growth of the flutter, resulting …

Multiple Channel Laser Beam Combination And Phasing Using Stimulated Brillouin Scattering In Optical Fibers, Brent W. Grime

Theses and Dissertations

Brightness scaling lasers using stimulated Brillouin scattering (SBS) in optical fibers is explored. A multiple-channel amplifier approach is used to increase the total power of a laser system while avoiding a significant burden on a single channel. The work explores two approaches utilizing both SBS beam cleanup and SBS piston error conjugation. A unique beam combiner that takes advantage of the SBS beam cleanup properties of a long, gradient-index multimode fiber was designed and tested. The beam combiner was developed to combine multiple-channel laser beams simultaneously with high input and output coupling efficiency. The design for the SBS beam combiner …

Structural Characteristics Of Carbon Nanofibers For On-Chip Interconnect Applications, Yusuke Ominami, Quoc Ngo, Alexander J. Austin, Hans Yoong, Cary Y. Yang, Alan M. Cassell, Brett A. Cruden, Jun Li, M. Meyyappan

Electrical and Computer Engineering

In this letter, we compare the structures of plasma-enhanced chemical vapor deposition of Ni-catalyzed and Pd-catalyzed carbon nanofibers (CNFs) synthesized for on-chip interconnect applications with scanning transmission electron microscopy (STEM). The Ni-catalyzed CNF has a conventional fiberlike structure and many graphitic layers that are almost parallel to the substrate at the CNF base. In contrast, the Pd-catalyzed CNF has a multiwall nanotubelike structure on the sidewall spanning the entire CNF. The microstructure observed in the Pd-catalyzed fibers at the CNF-metal interface has the potential to lower contact resistance significantly, as our electrical measurements using current-sensing atomic force microscopy indicate. A …

Fully Compliant Tensural Bistable Micro-Mechanisms (Ftbm), D. L. Wilcox, Larry L. Howell

Faculty Publications

A new class of bistable mechanisms, the fully compliant tensural bistable micromechanism (FTBM) class, is introduced. The class consists of linear bistable micromechanisms that undergo tension loads, in addition to the bending loads present, through their range of motion. Proof-of-concept designs fabricated in two different microelectromechanical systems (MEMS) surface micromachining processes were demonstrated. Three sets of refined designs within the FTBM class were designed using optimization methods linked with nonlinear finite element analysis (FEA), then fabricated and tested. Measured force and displacement performance are compared to values obtained by FEA. On-chip actuation of the bistable mechanisms was achieved using thermomechanical …

Top-Down Structure And Device Fabrication Using In Situ Nanomachining, Xiaodong Li, Xinnan Wang, Qihua Xiong, Peter C. Eklund

Faculty Publications

We demonstrate the potential of an alternative tool for the fabrication of nanoscale structures and devices. A nanoindenter integrated with an atomic force microscope is shown to be a powerful machine tool for cutting precise length nanowires or nanobelts and for manipulating the shortened wires. We also demonstrate its utility in cutting grooves and fabricating dents (or periodic arrays of dents) in ZnSnanobelts. This approach permits the direct mechanical machining of nanodevices that are supported on a substrate without the inherent complications of e beam or photolithography.

Toyota 180l Spiral Radiator Hose Design To Six Sigma Goal, Tay-Shing Chen

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Tay-Shing Chen on December 2, 2005.

Statnamic Lateral Load Testing And Analysis Of A Drilled Shaft In Liquefied Sand, Seth I. Bowles

Theses and Dissertations

Three progressively larger statnamic lateral load tests were performed on a 2.59 m diameter drilled shaft foundation after the surrounding soil was liquefied using down-hole explosive charges. An attempt to develop p-y curves from strain data along the pile was made. Due to low quality and lack of strain data, p-y curves along the test shaft could not be reliably determined. Therefore, the statnamic load tests were analyzed using a ten degree-of-freedom model of the pile-soil system to determine the equivalent static load-deflection curve for each test. The equivalent static load-deflection curves had shapes very similar to that obtained from …

Satellites In The Class Room, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Satellites in the Class Room" from December 2, 2005.

A Detailed Approach For Concept Generation And Evaluation In A Technology Push Product Development Environment, Andrew Nelson

Theses and Dissertations

Many companies rely on successful product development as a means to increase their revenues and expand their operations. Market pull, the most common form of product development, begins with a specific customer, and focuses on how to satisfy that customer's needs. Technology push is a product development process where a technology is first discovered, then embodied in products that may be marketed to specific customers. Technology push presents several obstacles not encountered in market pull processes, such as a lack of a defined market, lack of established processes and difficulty in execution. These complications keep technology push from being more …

Performance Analysis Of Common Detectors For Shaped Offset Qpsk And Feher's Qpsk, Tom Nelson, Michael D. Rice, Erik Perrins

Faculty Publications

Sponsorship: US Air Force Grant FA9302-05-C-0001. A detector architecture capable of detecting both shaped offset quadrature phase shift keying (SOQPSK-TG) and Feher's quadrature phase shift keying (FQPSK-JR) is developed and analyzed. Both modulations are embodied as fully interoperable modulations in the Interrange Instrumentation Group (IRIG) standard IRIG-106. It is shown that the common detector achieves near optimal bit error rate performance without knowledge of which modulation is used by the transmitter. The detection techniques are based on a common trellis-coded modulation representation and a common continuous phase modulation (CPM) representation for these two modulations. In addition the common pulse amplitude …

Sensors To Monitor Cfrp/Concrete Bond In Beams Using Electrochemical Impedance Spectroscopy, Sangdo Hong, Ronald S. Harichandran

Civil Engineering Faculty Publications

The use of inexpensive electrochemical impedance spectroscopy based sensor technology for nondestructive evaluation (NDE) of bond degradation between external carbon fiber-reinforced polymer (CFRP) reinforcement and concrete is examined. Copper tape on the surface of the CFRP sheet, stainless steel wire embedded in the concrete, and reinforcing bars were used as the sensing elements. Laboratory experiments were designed to test the capability of the sensors to detect the debonding of the CFRP from the concrete and to study the effect of short-term (humidity and temperature fluctuations) and long-term (freeze-thaw and wet-dry exposure and rebar corrosion) environmental conditions on the measurements. The …

Acuta Enews December 2005, Vol. 34, No. 12

ACUTA Newsletters

In This lssue

From the President............................... Patricia H. Todus, Northwestern University

Two Audio Seminars

Institutional Excellence Award Deadline

Tech Talk: Adjusting the Carburetor on Your Network Engine................. Kevin Tanzillo, Dux PR

FYI: Useful lnformation from the Campus........................ Student Monitor

Web Tip: Resource for Legislative/Regulatory lnfo................ Aaron Fuehrer, ACUTA lnformation Tech. Mgr.

Member Sites to See

lnfo Links............................ Randy Hayes, Univ. of Northern lowa

Board Report.................... Riny Ledgerwood, San Diego State Univ., ACUTA Sec./Treasurer

Thanks to Exhibitors for 2005

DC Update............................ Whitney Johnson, Retired, No. Michigan Univ.

Welcome New Members

ACUTA Online Press Room

Remembering Sue Fisher

Characterization Of Gdp-Mannose Pyrophosphorylase From Escherichia Coli O157:H7 Edl933 And Its Broad Substrate Specificity, Yung-Hun Yang, Young Bok (Abraham) Kang, Kwang-Won Lee, Tek-Hyung Lee, Sung-Soo Park, Bum-Yeol Hwang, Byung-Gee Kim

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

GDP-mannose pyrophosphorylase gene (ManC) of Escherichia coli (E. coli) O157 was cloned and expressed as a highly soluble protein in E. coli BL21 (DE3). The enzyme was subsequently purified using hydrophobic and ion exchange chromatographies. ManC showed very broad substrate specificities for four nucleotides and various hexose-1-phosphates, yielding ADP-mannose, CDP-mannose, UDP-mannose, GDP-mannose, GDP-glucose and GDP-2-deoxy-glucose.

Monte-Carlo-Type Techniques For Processing Interval Uncertainty, And Their Potential Engineering Applications, Vladik Kreinovich, J. Beck, Carlos M. Ferregut, A. Sanchez, George R. Keller, Matthew G. Averill, Scott A. Starks

Departmental Technical Reports (CS)

In engineering applications, we need to make decisions under uncertainty. Traditionally, in engineering, statistical methods are used, methods assuming that we know the probability distribution of different uncertain parameters. Usually, we can safely linearize the dependence of the desired quantities y (e.g., stress at different structural points) on the uncertain parameters xi - thus enabling sensitivity analysis. Often, the number n of uncertain parameters is huge, so sensitivity analysis leads to a lot of computation time. To speed up the processing, we propose to use special Monte-Carlo-type simulations.

Loss Aware Rate Allocations In H.263 Coded Video Transmissions, Xiao Su, Benjamin Wah

Faculty Publications

For packet video, information loss and bandwidth limitation are two factors that affect video playback quality. Traditional rate allocation approaches have focused on optimizing video quality under bandwidth constraint alone. However, in the best-effort Internet, packets carrying video data are susceptible to losses, which need to be reconstructed at the receiver side. In this paper, we propose loss aware rate allocations in both group-of-block (GOB) level and macroblock level, given that certain packets are lost during transmissions and reconstructed using simple interpolation methods at the receiver side. Experimental results show that our proposed algorithms can produce videos of higher quality …

Gamma-Ray Induced Photoconductivity In Pyrex, Quartz, And Vycor, Shoaib Usman, Lubna Shoaib, James N. Anno

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Results of an experimental investigation are reported on photoconductive response of Pyrex, Quartz and Vycor. This research was conducted as a feasibility study for developing a new gamma dose measurement device based on the principle of photoconductivity. However, data collected in this study are equally valuable for various other applications where these materials are to be used in high radiation field. Our experiments and analyzes indicated that the selected dosimeter materials exhibit photoconductivity and respond to changes in gamma dose rate within a useful range. Pyrex glass suffered radiation damage at a relatively high dose rate of 0.25 Gys/sup -1/. …

The Potential For Real-Time Traffic Crash Prediction, Mohamed Abdel-Aty, Anurag Pande, Liang Y. Hsia, Fathy Abdalla

Civil and Environmental Engineering

The development of freeway crash prediction models using intelligent transportation systems (ITS) archived data could be a substantial advancement in the field of real-time traffic management. Such models not only are expected to improve safety but also may go a long way to improve freeway operations by reducing incident-related congestion.

Because there is a need to use real-time traffic data emanating from loop detectors, the approach differs distinctly from previous studies estimating crash frequencies or rates on a certain freeway section through aggregate measures of flow (such as average daily traffic or hourly volumes).

Although the authors try to establish …

Ole Miss Engineer 2005

Ole Miss Engineer

No abstract provided.

Harmony Search For Structural Design, Zong Woo Geem, Kang Seok Lee, Chung-Li Tseng

Engineering Management and Systems Engineering Faculty Research & Creative Works

Various algorithms have been developed and applied to structural optimization, in which cross-sectional areas of structure members are assumed to be continuous. in most cases of practical structure designs, however, decision variables (cross-sectional areas) are discrete. This paper proposes a combinatorial optimization model for structural design using a new nature-inspired algorithm, harmony search (HS). HS is also compared to genetic algorithms through a standard truss example. Numerical results reveal that the proposed HS is a powerful search algorithm for combinatorial structure optimization.

Conceptual Simulation Modeling For Regional Distribution Center Systems, Kitti Setavoraphan

All-Inclusive List of Electronic Theses and Dissertations

This study focuses on the simulation modeling of warehousing operations commonly seen at general merchandize distribution centers. The key operational processes and modeling requirements related were identified and analyzed through a pattern and knowledge-based approach to capture the structural and behavioral characteristics of general distribution centers to support simulation study for performance evaluation and process improvement. Robust representations and patterns were developed to represent the elements and logic of the simulation models for these processes to facilitate efficient and effective construction of models. The issues of conceptual modeling such as synthesis, abstraction, decomposition, and specialization were addressed.

The Procedural Due Process Requirements For No-Fly Lists, Soumya Panda

The University of New Hampshire Law Review

[Excerpt] “Imagine arriving at the airport and checking in at the ticketing booth. You tell the ticketing agent your name, your flight number, and show the agent your identification. The agent enters the information into the terminal and a look of shock appears on his or her face. While other passengers are waiting behind you, the agent calls for security and mentions in front of other passengers that you are denied from boarding the plane. Now imagine that you are a famous United States senator arriving from a political convention and the ticketing agent tells you that you cannot board …

Bayer Ag V. Housey Pharmaceuticals: Protection For Biotechnological Research Tools Under Section 271(G) Found Wanting, Matthew Barthalow

The University of New Hampshire Law Review

[Excerpt] "Research tools, a subset of biotechnological inventions protected by process patents, are “tools that scientists use in the laboratory, including cell lines, monoclonal antibodies, reagents, animal models, growth factors, combinatorial chemistry and DNA libraries, clones and cloning tools (such as PCR), methods, laboratory equipment and machines.” Many companies base their business models on the ability to find pharmaceutical products using their proprietary drug discovery research tools. Research tools used for drug discovery ‘include bioinformatic methods for identifying the interaction of certain proteins and their association with disease, methods for confirming protein targets, screening assays to identify molecules active against …

Numerical Study Of Chemically Reacting Viscous Flow Relevant To Pulsed Detonation Engines, Tae-Hyeong Yi

Mechanical and Aerospace Engineering Dissertations - Archive

A computational fluid dynamics code for two-dimensional, multi-species, laminar Navier-Stokes equations is developed to simulate a recently proposed engine concept for a pulsed detonation based propulsion system and to investigate the feasibility of the engine of the concept.The governing equations that include transport phenomena such as viscosity, thermal conduction and diffusion are coupled with chemical reactions. The gas is assumed to be thermally perfect and in chemically non-equilibrium. The stiffness due to coupling the fluid dynamics and the chemical kinetics is properly taken care of by using a time-operator splitting method and a variable coefficient ordinary differential equation solver. A …

Modular Multi-Scale Assembly System For Mems Packaging, Rakesh Murthy

Mechanical and Aerospace Engineering Theses - Archive

A multi-scale robotic assembly problem is approached here with focus on mechanical design for precision positioning at the microscale. The assembly system is characterized in terms of accuracy/repeatability and calibration via experiments. The MEMS packaging requirements are studied from an assembly point of view. The tolerance budget of the assembly ranges from 4 microns to 300 microns. The system components include robots, microstages, end-effectors and fixtures that accomplish the assembly tasks. Task assignment amongst this hardware has been accomplished based on precision and dexterity availability. Various end-effectors and fixtures have been designed for use with off-the-shelf hardware (robots and microstages) …

Interactions Between Antiwear Agent And Novel Additive In Engine Oils, Kajal Parekh

Material Science and Engineering Theses - Archive

Research has shown that side/end products of phosphorus and sulfur compounds in engine oils reduce effective life of exhaust catalysts of automobiles resulting in harmful emissions. Thus environmental regulations have been imposed on phosphorus levels in engine oils. The main source of phosphorus in today's oils is the indispensable antiwear agent Zinc Dialkyl Dithiophosphate (ZDDP). To find cost-effective non-phosphorus substitute has not proven fruitful. A unique way of reducing phosphorus or ZDDP level while maintaining good antiwear performance has been achieved by introduction of a novel additive FeF3 along with ZDDP. It appears that the interactions between FeF3 and ZDDP …

Design And Analysis Of Multi-Functional Laparoscopic Tool, Vadakkapattu Candadai Venkat Raghavan

Mechanical and Aerospace Engineering Theses - Archive

Laparoscopic tools have been developed over many years, but there is a need for a laparoscopic tool that can be used for multiple purposes without the need to be removed and reinserted in the body. This thesis discusses the design of such a multi-functional laparoscopic tool with the ability to independently actuate grasping and shearing mechanisms, and is modular enough to be easily adapted to robot assisted surgical techniques. The envisioned tool can be divided into three main sections - the surgeon interface, the transmission mechanism, and the end effector. The surgeon interface mainly consists of a handle and two …