Engineering Commons^™

The Relationship Between Basic Multicellular Unit Activation And Origination In Cancellous Bone, C. J. Hernandez, S. J. Hazelwood, R. B. Martin

Biomedical Engineering

Activation frequency is often used as a measure of basic multicellular unit (BMU) activity in cancellous bone. However, activation frequency expresses the rate of BMU appearance in a histologic slide and not the rate of origination, which is a more physiologic indicator of remodeling activity and is necessary for the development of BMU-level bone remodeling simulations. Using identical assumptions to those for calculating the activation frequency, it is shown that the origination frequency in cancellous bone is equal to the activation frequency divided by the total distance traveled by the BMU and its width.

Gauge Repeatability & Reproducibility Study For A 3-D Solder Paste Inspection System, Jianbiao Pan, Gregory L. Tonkay, Robert H. Storer, Ronald M. Sallade, David J. Leandri

Industrial and Manufacturing Engineering

Due to the increased use of Ball Grid Arrays (BGAs) and fine pitch and ultra fine pitch Quad Flat Packages (QFPs), there is a dramatic increase in demand for solder paste inspection after the stencil printing process. The important response variables of the printing process are deposited solder paste volume, area, height and position. To identify and remove defects at the earliest possible process step, a 3-D solder paste inspection system should be used to monitor solder paste deposited on all pads on every board before component placement. An example is a fully automatic laser-based 3-D triangulation solder paste inspection …

Letters To The Editor: Filtering Property Of A Lightly Damped System, Subjected To Transient Excitation, M. F. Dimentberg, Mohammad N. Noori

Office of the Dean (CENG) Scholarship

No abstract provided.

Critical Variables Of Solder Paste Stencil Printing For Micro-Bga And Fine Pitch Qfp, Jianbiao Pan, Gregory L. Tonkay, Robert H. Storer, Ronald M. Sallade, David J. Leandri

Industrial and Manufacturing Engineering

Stencil printing continues to be the dominant method of solder deposition in high volume surface mount assembly. Control of the amount of solder paste deposited is critical for fine pitch and ultra-fine pitch SMT assembly. The process is still not well understood as indicated by the fact that industry reports 52-71% of SMT defects are related to the solder paste stencil printing process. The purpose of this paper is to identify the critical variables that influence the deposited solder paste volume, area, and height. An experiment was conducted to investigate the effects of relevant process parameters on the amount of …

Current Canal Modernization From An International Perspective, Charles M. Burt

BioResource and Agricultural Engineering

Modernization differs from rehabilitation, which simply returns a deteriorated project or structures to their original new state. Rehabilitation by itself typically only perpetuates the vicious cycle of rehabilitation, deterioration, rehabilitation, etc. A modern irrigation design is the result of a thought process that selects the configuration and the physical components in light of a well-defined and realistic operation plan that is based on the service concept. A modern irrigation design is not defined by specific hardware components and control logic. Advanced concepts of hydraulic engineering, irrigation engineering, agronomy, and social science should be used to arrive at the most simple …

Case Study: Modernization Of The Government Highline Canal, Stuart W. Styles, Charles M. Burt, Ram Dhan Khalsa, Robert Norman

BioResource and Agricultural Engineering

The Government Highline Canal Modernization Study was completed to evaluate options for reducing the flow rate requirement of the Government Highline Canal during the late Summer and Fall water delivery months. The intent was to develop a design for which Colorado River diversions could be better matched to on-farm demands. The two primary challenges associated with reducing diversions are that (i) at low canal flows many turnouts do not have sufficient pressure, and (ii) it is difficult to schedule diversions to match deliveries. The Government Highline Canal is part of the federal Grand Valley Project in the Colorado River Basin …

Modernization Of The Delano-Earlimart Irrigation District, Charles M. Burt, Dale R. Brogan

BioResource and Agricultural Engineering

Delano-Earlimart Irrigation District (DEID) delivers water through closed reinforced concrete pipelines on an arranged schedule. Farmers are not allowed to operate their own turnouts, and individual turnout flow rate changes impact flow rates at all other turnouts on the same pipeline. DEID is in the process of a complete modernization program which will allow the farmers to operate their own turnouts on a very flexible arranged schedule. The modernization includes (i) a new water ordering program, (ii) new turnout designs with pressure regulators and new flow propeller flow meters, (iii) the use of hand held data recorders to document deliveries …

Case Study: Modernization Of The Patterson Irrigation District, Stuart W. Styles, Charles M. Burt, Mike Lehmkuhl, John Sweigard

BioResource and Agricultural Engineering

The Irrigation Training and Research Center (ITRC) at Cal Poly in San Luis Obispo, California has been working in conjunction with the Patterson Irrigation District (PID) on modernization of the district facilities. This project is being partially funded by the United States Bureau of Reclamation (USBR) Mid-Pacific Region. The district is located in the San Joaquin Valley of California. Water supply for the district is pumped primarily from the San Joaquin River. The district utilizes a series of pump stations and canal pools to bring water uphill to supply the lateral canals, which are laid out on the contour. Modernization …

Parallel Ac-Ac Converters Using Stationary Master Slave Control, Taufik, F. E. Villaseca

Electrical Engineering

This study proposes parallel ac-ac converters using Stationary Master Slave Control with Sinusoidal Pulse Width Modulation to achieve voltage regulation and equal current sharing among parallel generators such that it minimizes the total production cost. Development of Pspice model representing the parallel ac-ac converters is presented and then simulated. In addition, computer simulations are also used to perform robustness study on the parallel converters.

Temperature Dependence Of Electrical And Optical Modulation Responses Of Quantum-Well Lasers, T. Keating, Xiaomin Jin, Shun Lien Chuang, K. Hess

Electrical Engineering

We present theory and experiment for high-speed optical injection in the absorption region of a quantum-well laser and compare the results with those of electrical injection including the carrier transport effect. We show that the main difference between the two responses is the low-frequency roll-off. By using both injection methods, we obtain more accurate and consistent measurements of many important dynamic laser parameters, including the differential gain, carrier lifetime, K factor, and gain compression factor. Temperature-dependent data of the test laser are presented which show that the most dominant effect is the linear degradation of differential gain and injection efficiency …

Application Of A Fiber-Reinforced Continuum Theory To Multiple Deformations Of The Annulus Fibrosus, Stephen M. Klisch, Jeffrey C. Lotz

Mechanical Engineering

Accurate tissue stress predictions for the annulus fibrosus are essential for understanding the factors that cause or contribute to disc degeneration and mechanical failure. Current computational models used to predict in vivo disc stresses utilize material laws for annular tissue that are not rigorously validated against experimental data. Consequently, predictions of disc stress resulting from physical activities may be inaccurate and therefore unreliable as a basis for defining mechanical–biologic injury criteria. To address this need we present a model for the annulus as an isotropic ground substance reinforced with two families of collagen fibers, and an approach for determining the …

Optical Gain Measurements Based On Fundamental Properties And Comparison With Many-Body Theory, T. Keating, S. H. Park, J. Minch, Xiaomin Jin, Shun-Lien Chuang, T. Tanbun-Ek

Electrical Engineering

We present high accuracy measurements of gain, loss, and transparency energy in long-wavelength semiconductors based on a hybrid approach using the fundamental relationship between the gain and the spontaneous emission spectra. Independent measurements of optical gain, transparency energy, and loss show the accuracy and validity of this technique. These results are compared with those obtained by the non-Markovian gain model with many-body effects under the spontaneous emission transformation method. It is found that the hybrid approach for the gain spectrum alleviates many of the problems related to the poor signal to noise ratio in the amplified-spontaneous emission near and below …

Discovery Of Design Methodologies, Cirrus Shakeri, David C. Brown, Mohammad N. Noori

Office of the Dean (CENG) Scholarship

In this paper we present an AI-based approach for the discovery of design methodologies for multi-disciplinary design situations. The approach is based on simulating the design process using a multi-agent system that mimics the behavior of the design team. The system activates the pieces of design knowledge when they become applicable. The use of knowledge by agents is recorded by tracing the steps that the agents have taken during a design project. Many traces are generated by solving a large number of design projects that differ in their requirements. A set of design methodologies is constructed by using clustering techniques …

Theoretical And Experimental Investigation On The Low Temperature Properties Of The Nbcr2 Laves Phase, Dan J. Thoma, Chu Fuming, Katherine C. Chen, Paul G. Kotula, Terence E. Mitchell, John M. Wills, Alim Ormeci, Shao Ping Chen, Robert C. Albers

Materials Engineering

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The goal of the project was to develop methodologies in which to define and improve the properties of NbCr₂ so that the high temperature structural applications of alloys based upon this would not be limited by the low-temperature brittle behavior of the intermetallic. We accomplished this task by (1) understanding the defect structure and deformation mechanisms in Laves phases, (2) electronic and geometric contributions to phase stability and alloying behavior, and (3) novel processing of dual phase (Laves/bcc) …

Screen Printing Process Design Of Experiments For Fine Line Printing Of Thick Film Ceramic Substrates, Jianbiao Pan, Gregory L. Tonkay, Alejandro Quintero

Industrial and Manufacturing Engineering

Screen printing has been the dominant method of thick film deposition because of its low cost. Many experiments in industry have been done and many models of the printing process have been developed since the 1960's. With a growing need for denser packaging and a drive for higher pin count, screen printing has been refined to yield high resolution prints. However, fine line printing is still considered by industry to be difficult. In order to yield high resolution prints with high first pass yields and manufacturing throughput, the printing process must be controlled stringently.

This paper focuses on investigating the …

Evaluation Of Caltrans District 10 Automated Warning System, Year Two Progress Report, Art Maccarley

Electrical Engineering

District 10 of the California Department of Transportation (Caltrans) encompasses an area of seasonal fog and dust-related visibility problems that have been the cause of numerous multi-car traffic collisions, many fatal. In 1990, motivated by the expansion of State Route 120 (SR 120) connecting Interstate Highway 5 (I-5) and State Route 99 (SR 99), Caltrans proposed a sophisticated multi-sensor automated warning system as a means for reducing incidents in this high-traffic area. This proposal, and the significant development effort that followed, culminated in the implementation of Phase 1 of the Caltrans Automated Warning System, or “CAWS”, which entered service in …

An Efficient Finite Difference Time Domain (Fdtd) Technique For Modeling A Reflector Antenna System With Partial Circular Symmetry, Dean Arakaki, Wenhua Yu, Raj Mittra

Electrical Engineering

This paper presents an efficient method for solving a large body scattering problem, viz., a paraboloidal reflector antenna system with only partial circular symmetry. The asymmetry in the system is introduced by two factors, viz., the microstrip feed and an inhomogeneous radome. The paper presents a novel approach, based on the reciprocity principle and the “equivalent aperture” theory, to handle the asymmetry problem and still take advantage of the circular symmetry of the large paraboloid of revolution to render the problem manageable

Closure To Period Formulas For Concrete Shear Wall Buildings, Anil K. Chopra, Rakesh K. Goel

Civil and Environmental Engineering

No abstract provided.

The Effect Of Stimulus Current Pulse Width On Nerve Fiber Size Recruitment Patterns, Robert B. Szlavik, Hubert De Bruin

Biomedical Engineering

There have been theoretical studies presented that postulate a change in the stimulus current amplitude required to recruit nerve fibers with different stimulus current pulse widths. Based on these theoretical predictions, it has been suggested that the stimulus pulse width parameter may be used to selectively recruit fibers of different sizes and that this selectivity should increase with increasing distance from the stimulus electrode. In this paper, a simulation study of the recruitment patterns of a population of motor nerve fibers with a histologically accurate fiber diameter distribution is presented. Nerve fiber excitation simulations coupled with a time varying field …

In Vivo Electrical Stimulation Of Motor Nerves, Robert B. Szlavik

Biomedical Engineering

Stimulus waveform parameters and stimulation protocols are fundamental to the use of electrical stimulation in medical applications. This thesis presents new simulation and experimental procedures that for the first time can quantify the effects on nerve fiber recruitment patterns of variable stimulus waveform parameters, such as pulse width and changes in the stimulation protocol with respect to electrode orientation. The study of the effect of variable electrical stimulus waveform parameters and stimulation protocols is important from the perspective of therapeutic and diagnostic medicine. Variations in the stimulus waveform such as stimulus pulse width have been shown to offer some promise …

Electroluminescent Illumination System, Dirk J. Broer, David Braun, Antonius H.J. Venhuizen, Christianne R.M. De Witz

Electrical Engineering

An illumination system has an active layer which includes an electroluminescent material, the active layer being located between an optically transparent electrode layer and a reflective electrode layer. A reflective polarizer is present at a side of the transparent electrode layer facing away from the active layer. A sub-beam incident on the polarizer and having an unwanted polarization is reflected back to the active layer, where it is again partially depolarized to recover a component having the desired state of polarization. The invention also relates to a flat-panel picture display device which includes such an illumination system.

Environmental Applications Of Gps, Samuel A. Vigil, Dora Zueck

Civil and Environmental Engineering

The use of the Global Positioning System (GPS) has revolutionized air travel, ocean navigation, land navigation, and the collection of environmental data. Although a basic civilian GPS receiver can be purchased for as little as $100, the receiver is only the tip of a 12 billion dollar iceberg! This paper will discuss the history and basic operation of the Global Positioning System, a satellite-based precision positioning and timing service developed and operated by the Department of Defense. It will also describe the accuracy limitations of the civil GPS service and how accuracy can be enhanced by the use of differential …

Application Of Noise Control In Environmental Engineering Education, Harold M. Cota, Kristy Grace

Civil and Environmental Engineering

Noise control is both a factor in the health and safety of those in the workplace and in the annoyance and interference of the quality of life at home. This falls squarely in the realm of the Environmental Engineering Profession. Noise, its effects and control, is an important element of a few Graduate Environmental Engineering Programs, but it does not have a role in most undergraduate programs. One objective of this paper is to demonstrate that noise is an issue needing to be addressed in Environmental Engineering Programs and to suggest that making it a requirement at the undergraduate level …

Early Experimentation With Civil Engineering Materials, James L. Hanson

Civil and Environmental Engineering

A new project-based teaching method emphasizing laboratory experimentation is being used at Lawrence Technological University. It has excited and energized the students about civil engineering applications. Engineering concepts are introduced early in the students’ academic careers using civil engineering materials. Laboratory activities related to a Civil Engineering Materials course are being used for outreach, recruitment, and an intensive laboratory experience. A departmental effort has included supporting an outreach program and expanding a freshman CE Materials course. This new teaching method has affected and complemented university recruitment and retention efforts. The course introduces incoming students to engineering analysis and the basic …

Training Graduate Student Instructors Effectively: The University Of Michigan Model, Trevor S. Harding

Materials Engineering

No abstract provided.

Industrial Engineering Made Simple, Deena Daggett, Sema E. Alptekin

Industrial and Manufacturing Engineering

Many high school students these days do not quickly recognize or identify Industrial Engineering (IE) procedures, practices, and products. Recruitment of qualified students into IE programs requires continuous planning, publicizing, and networking. Traditional recruitment efforts have included high school visits, brochures & flyers, and university-sponsored workshops. However, these techniques have only achieved mediocre success. Currently, a need exists for new promotional materials that utilize visual tools and provide a “hands-on” approach. We have developed several exercises that successfully introduce IE. Two such exercises are explained in this paper. The first exercise demonstrates the differences between Assembly line and Cellular Manufacturing …

Crosstalk And Image Uniformity In Passive Matrix Polymer Led Displays, David Braun, J. Rowe, G. Yu

Electrical Engineering

Passive matrix displays based on polymer and organic light-emitting diodes suffer from crosstalk, when the emission of light from one pixel depends on the operation of another pixel. We use circuit simulation in order to explain the causes of crosstalk and to quantify the consequences. This work analyzes how crosstalk arises from electrode resistance, pixel leakage current, and the location of faulty pixels. All factors influence both image uniformity and the power consumption of the display.

Possible Explanations Of Phase Transitions In Highway Traffic, C.F. Daganzo, M.J. Cassidy, Robert L. Bertini

Civil and Environmental Engineering

It is shown that all the phase transitions in and out of freely flowing traffic reported earlier for a German site could be caused by bottlenecks, as are all the transitions observed at two other sites examined here. The evidence suggests that bottlenecks cause these transitions in a predictable way, and does not suggest that stoppages (jams) appear spontaneously in free flow traffic for no apparent reason. It is also shown that many of the complicated instability phenomena observed at all locations can be explained qualitatively in terms of a simple Markovian theory specific to traffic that does not necessarily …

Sensors Location Effect On The Dynamic Behaviour Of The Composite Structure With Flaw Detection, Eltahry Elghandour, Faysal Kolkailah, Abdel- Hamid I. Mourad

Aerospace Engineering

In this paper presents an experimental and numerical investigation ofthe natural frequency of composite material cantilever plates. The stacking sequence of tbe composite plate is Quasi-isotropic laminated plate is [2(0j/±45°/2(90°)]" The plate was subjected to incremental cuts and tests to determine changes in new modal properties. The study included white noise and sinusoidal dynamic testing techniques and a virtual instrument dynamic analyzer. In this study also, determining the resonant frequencies of the undamaged and damaged plate, and evaluating the capabilities of piezoelectric ceramics (PZT's) for fault detection based on their sensitivity and accuracy changes in modal parameters. Numerical results are …

Mixed Mode Stable Crack Extensions Through Stiffened Specimens, Abdel-Hamid I. Mourad, Eltahry Elghandour, Faysal A. Kolkailah

Aerospace Engineering

This study presents an experimental investigation of fracture mechanics for isotropic material, aluminum alloy D16AT. The problem of stable crack growth (SCG) has been addressed in this paper. Experimental results are presented for symmetrically stiffened and unstiffened three point bend specimens subjected to different modes, mode I and mixed mode. The stiffeners are doubly bonded to the fatigue pre-cracked specimens parallel to the length at a certain distance behind the crack tip using an adhesive Redux 410 NA. Results concerning load displacement variation, growth of plastic zones, instantaneous crack edge profiles, and tunneling are presented. There is evidence that the …