Engineering Commons^™

Capacity And Stiffness Of Bridge Abutments During Earthquakes, Rakesh K. Goel

Civil and Environmental Engineering

No abstract provided.

The Threshold Value Of A Quality Index For Formation Of Cellular Manufacturing Systems, Hamid Seifoddini, Manocher Djassemi

Industrial Technology and Packaging

The superiority of cellular manufacturing to job shop manufacturing has been questioned by a number of simulation studies. The initial structure of the machine-part matrix seems to play an important role in the failure of cellular manufacturing systems in these studies. In this paper a grouping measure called 'quality index - QI' will be used to evaluate the relationship between the quality of a machine-part matrix and the performance of the corresponding cellular manufacturing system. A simulation study will be conducted to demonstrate how the procedure can be used to determine the threshold value for QI beyond which the cellular …

Modern Water Control And Management Practices In Irrigation: Methodoloy And Criteria For Evaluating The Impact On Performance, Charles M. Burt

BioResource and Agricultural Engineering

No abstract provided.

Preparing The Leaders For Mechatronics Education, Sema E. Alptekin

Industrial and Manufacturing Engineering

Mechatronics is the synergetic combination of precision mechanical engineering, electronic control and systems thinking in the design of products and processes. There is a need to develop interdisciplinary programs in Mechatronics that better prepare our graduates to design, build, and operate the products and systems of today and tomorrow. To address this need, National Science Foundation funded a project entitled "Preparing the Leaders for Mechatronics Education" undertaken by Cal Poly in 1995 - 1996. In this paper, the activities that took place during this two-year program is outlined. Several courses and course modules have already been developed and implemented by …

Development Of Outcome Assessments At Wpi, William W. Durgin, Lance Schachterle

Office of the Provost Scholarship

The WPl PLAN, adopted by the WPl faculty in 1970, strongly anticipates current thinking about student outcomes assessments by structuring degree requirements that mandate that students demonstrate their ability to perform professional functions embodied in ABET Criteria 2000, especially Criteria 3 and 4. The WPI faculty has also practiced both student and self evaluations of these outcomes through respectively grades and peer review (both departmental and campus-wide) of student performance.

Distributed Activation Energy Model Of Heterogeneous Coal Ignition, John C. Chen

Mechanical Engineering

We present a model that simulates the conventional tube-furnace experiment used for ignition studies. The Distributed Activation Energy Model of Ignition accounts for particle-to-particle variations in reactivity by having a single preexponential factor and a Gaussian distribution of activation energies among the particles. The results show that the model captures the key experimental observations, namely, the linear increase in ignition frequency with increasing gas temperature and the variation of the slope of the ignition frequency with oxygen concentration. The article also shows that adjustments to the model parameters permit a good fit with experimental data.

Row Crop Drip Irrigation On Peppers Study, Charles M. Burt, Stuart Styles

BioResource and Agricultural Engineering

High Rise Farms, located just north of Morgan Hill installed a new buried row crop drip irrigation system in 1993. The amount of the CEC loan was $42,700.

The installation of the drip irrigation system on the Peppers did provide significant improvements in the amount of water use, energy required and yield increases especially in the first year of operation (1993) and the third year of operation (1995). The second year of the project (1994) did not have yield increases. The primary lessons learned from this project included:

• The yield differential between drip and the furrow irrigation methods was attributed …

Row Crop Drip Irrigation On Bell Peppers Study, Charles M. Burt, Stuart Styles

BioResource and Agricultural Engineering

Underwood Ranches, located near Oxnard, installed a buried drip system on 50 acres of peppers in 1993. The amount of the CEC loan was $50,000.

The buried drip system provided sufficient advantages in water management, energy savings, and yield increases to convince the farm to expand its drip acreage to 140 acres in June 1995, and 320 acres in Sept. 1996. The farmer was an ideal cooperator.

The primary lessons learned on this project were:

• A grower needs approximately two years of experience and technical assistance in order to feel comfortable with a buried drip system. Even after that time, …

Random Response To Periodic Excitation With Correlated Disturbances, Zhikun Hou, Yunshen Zhou, Mikhail F. Dimentberg, Mohammad N. Noori

Office of the Dean (CENG) Scholarship

The paper addresses non-Gaussian stationary response of linear single-degree-of-freedom (SnOF) systems subject to a periodic excitation with correlated random amplitude and phase disturbances that are modeled as correlated Gaussian white noise processes. Correlation between amplitude and phase modulation is specified by the cross-correlation coefficient. Numerical results for the second and fourth moment responses are presented. The probability density function of the response is calculated based on the cumulant-neglect closure method. Non-Gaussian nature of the response is discussed in terms of the excess factor. The results show that the moment responses generally increase with larger random amplitude disturbance and may decrease …

Pulsed Transient Tissue Conductivity Measurement, Robert B. Szlavik, Hubert De Bruin

Biomedical Engineering

The authors present an alternative technique for obtaining tissue conductivity as a function of frequency. Pulsed transient tissue impedance measurement differs significantly from other commonly used swept frequency techniques in that the conductivity of a tissue sample can be obtained from a voltage transient response to a current pulse. By obtaining the conductivity across a band of frequencies from a transient measurement, the necessity for direct conductivity measurements at each frequency point is eliminated. Calibration and verification of the technique was carried out by measuring the impedance magnitude and phase of simple RC circuit combinations. The authors present conductivity measurements …

Spice Compatible Equivalent Circuit Models Of Skeletal Muscle Tissue, Robert B. Szlavik, Hubert De Bruin

Biomedical Engineering

The authors present equivalent circuit models of skeletal muscle tissue for the directions parallel and transverse to the fiber. The parallel model is based on a distributed parameter equivalent circuit approach where the tissue between the electrodes is divided into small segments, each of which is represented by an equivalent circuit. Parameters for the equivalent circuits me calculated from the electrical characteristics of the tissue components and their physical arrangement. The authors compare the conductivity frequency response of the equivalent circuit modelling approach to other models presented in the literature. The advantage to the authors' equivalent circuit approach is that …

Sensitivity Analysis In Cellular Manufacturing System In The Case Of Product Mix Variation, Hamid Seifoddini, Manocher Djassemi

Industrial Technology and Packaging

In this paper, performance measures such as mean flow time and work-in-process inventories will be used to determine the changes in the performance of a cellular manufacturing system due to product mix variations.

Calcium Buffering Is Required To Maintain Bone Stiffness In Saline Solution, M. B. Gustafson, R. B. Martin, V. Gibson, D. H. Storms, S. M. Stover, J. Gibeling, L. Griffin

Biomedical Engineering

This work determined whether mineral dissolution due to prolonged testing or storage of bone s~'imens in normal salint: would alter Lheir elastic modulus. In one experiment, small pieces of equine third metacarpal bone were soaked in normal saline supplemented with varying amounts of CaCI1. Changing Ca ion concentrations in the bath were monitored and the equilibrium concentration was determined. In a second experiment, the elastic moduli of twenty 4 x 10 x 100 mm equine third metacarpal beams were determined non-destructively in four-point bending. Half the beams were then soaked for 10 days in normal saline, and the other half …

In Vitro Fatigue Behavior Of The Equine Third Metacarpus: Remodeling And Microcrack Damage Analysis, R.B. Martin, V.A. Gibson, S.M. Stover, J.C. Gibeling, L.V. Griffin

Biomedical Engineering

We studied remodeling and microcrack damage in specimens of Thoroughbred racehorse third metacarpal bone that had been subjected to monotonic or fatigue failure. We asked three questions. What effects does mechanical loading have on histologically observable microcrack damage? Are there regional variations in remodeling of the equine cannon bone, and do these variations correlate with mechanical properties? To what extent are remodeling and microcrack damage age-dependent? Machined beams from the medial, lateral, and dorsal cortices were loaded to fracture in four-point bending monotonically, or cyclically at a load initially producing 10,000 microstrain. Specimens were then bulk-stained in basic fuchsin, and …

Improving The Performance Of Cellular Manufacturing By A Dynamic Part Assignment Approach, Hamid Seifoddini, Manocher Djassemi

Industrial Technology and Packaging

In this paper, a simple dynamic part assignment (DPA) procedure is introduced and its effects on the performance of cellular manufacturing systems is evaluated. In this procedure rerouting of parts among machine cells is allowed for better machine utilization. Three data sets are used to compare the performance of manufacturing systems under job shop and cellular manufacturing when DPA is employed. The results of simulation runs indicate that the proposed DPA method improves the performance of cellular manufacturing significantly by reducing the congestion in machine cells with long waiting lines.

Integrating Multidisciplinary Design In An Undergraduate Curriculum, Russell M. Cummings, H. Jo Anne Freeman

Aerospace Engineering

Multidisciplinary design and analysis has become the normal mode of operation within most aerospace companies, but the impact of these changes have largely not been reflected at many universities. In an effort to determine if the emergence of multidisciplinary design concepts should influence engineering curricula, NASA has asked several universities (Virginia Tech, Georgia Tech, Clemson, BYU, and Cal Poly) to investigate the practicality of introducing the concepts within their undergraduate curricula. A multidisciplinary team of faculty, students, and industry partners evaluated the aeronautical engineering curriculum at Cal Poly. A variety of ways were found to introduce multidisciplinary themes into the …

Real-Time Range Image Segmentation Using Adaptive Kernels And Kalman Filtering, Fred W. Depiero, Mohan M. Trivedi

Electrical Engineering

Segmentation is a fundamental process affecting the overall quality and utility of a machine vision system. Range Profile Tracking (RPT) is a systematic approach for stable, accurate and high speed segmentation of range images that is based on Kalman filtering. Tests of RPT have produced stable decompositions of second order surfaces bounded by jump and crease discontinuities, having a volumetric error of a few percent, in under 6 sec. for a wide variety of conditions. Results from over 900 tests on synthetic scenes and 150 real range images are presented.

Simple Rail-To-Rail Constant-Transconductance Input Stage Operating In Strong Inversion, Vladimir I. Prodanov, Michael M. Green

Electrical Engineering

A CMOS op-amp input and gain stage suitable for low voltage operation are introduced. The input stage operates in strong inversion and has common-mode range beyond rail-to-rail. It uses two complementary differential pairs connected in parallel. The common-mode dependent current biasing employs only four transistors, does not require additional voltage references, current switches and/or current mirrors and does not increase the minimum required supply voltage. The variation of the net transconductance is approximately 15% over the entire common-mode range. The gain-stage has constant output resistance. In addition it reduces the variation of the net transconductance due to variations in μn/μp …

Osteonal Structure In The Equine Third Metacarpus, R. B. Martin, V. A. Gibson, S. M. Stover, J. C. Gibeling, L. V. Griffin

Biomedical Engineering

In studying the flexural fatigue properties of the equine third metacarpal (cannon) bone, we previously found that the dorsal region was weaker monotonically, but more fatigue resistant, than the lateral region. Fatigue resistance was associated with fracture surfaces which demonstrated that secondary osteons had “pulled out” of the surrounding matrix; this never happened in lateral specimens. We therefore became interested in the osteonal structure of this bone, and began to study its birefringence patterns in circularly polarized light. We found that the predominant type of secondary osteon was one in which only the outermost few lamellae were circumferential, with the …

Solute Nucleation And Growth In Supercritical Fluid Mixtures, Gregory T. Smedley, Gerald Wilemski, W. Terry Rawlins, David B. Oakes, Prakash Joshi, William W. Durgin

Office of the Provost Scholarship

This research effort is directed toward two primary scientific objectives: (1) to determine the gravitational effect on the measurement of nucleation and growth rates near a critical point and (2) to investigate the nucleation process in supercritical fluids to aid in the evaluation and development of existing theoretical models and practical applications. A nucleation pulse method will be employed for this investigation using a rapid expansion to a supersaturated state that is maintained for ≈ 1 ms followed by a rapid recompression to a less supersaturated state that effectively terminates nucleation while permitting growth to continue. Nucleation, which occurs during …

Source Reduction And Recycling Programs At A Joint Venture Automobile Assembly Plant, Stuart E. Rupp, Samuel A. Vigil

Civil and Environmental Engineering

New United Motor Manufacturing, Inc. (NUMMI) is a vehicle assembly plant in Fremont, California. NUMMI began operations in 1984 as ajoint venture of General Motors Corporation and Toyota Motor Corporation. In 1995, NUMMI produced 94,280 Geo Prizms, 135,112 Toyota Corollas, and 123,257 Toyota Tacoma trucks. NUMMI conducts its manufacturing operations using the Toyota Production System (TPS). A key element of TPS is the elimination of waste. This includes wasted energy, space, labor, and production materials. Waste reduction, i.e., source reduction, is part of NUMMI's corporate culture and every team member is encouraged to continuously seek out new waste reduction opportunities. …

Modeling Of Macroscopic/Microscopic Transport Phenomena In Zeolite Crystal Solutions Under Microgravity Conditions, Andreas Alexandrou, Nikos A. Gatsonis, William W. Durgin, Albert Sacco, Jr.

Office of the Provost Scholarship

Crystals grown from special liquid solutions find important industrial applications. Most often the physics and chemistry of the growth processes are not well understood due to complex microscopic chemical and thermo-fluid phenomena. Microgravity could help elucidate these phenomena and allow the control of defect concentration and crystal size. We are proposing to study zeolites grown in silica solutions as a typical crystal growth system. By using macroscopic fluid dynamics, coupled with first-principle microscopic fluid physics and advanced particle simulations, we will study: (a) the effect of transport phenomena and nutrient flow under microgravity conditions along with (b) the nucleation process …

Graph Matching Using A Direct Classification Of Node Attendance, Fred Depiero, Mohan Trivedi, Steve Serbin

Electrical Engineering

An algorithm has been developed that finds isomorphisms between both graphs and subgraphs. The development is introduced in the object recognition problem domain. The method isolates matching subgraphs, finds a node-to-node mapping and reorders nodes, thus permitting a direct comparison to be made between the resultant graphs. The algorithm is of polynomial order. It yields approximate results, maintaining a performance level for subgraph isomorphisms at or above 95% under a wide variety of conditions and with varying levels of noise. The performance on the full size comparisons associated with graph isomorphisms has been found to be 100/100, also under a …

Analysis Of The Elements Of Drag In Three-Dimensional Viscous And Inviscid Flows, Russell M. Cummings, M. B. Giles, G. N. Shrinivas

Aerospace Engineering

This paper examines the analytical, experimental, and computational aspects of tlie determination of the drag acting on an aircraft in flight, with or without powered engines, for subsonic/transonic flow. Using a momentum approach, the drag is represented by an integral over a cross-flow plane at an arbitrary distance behind the aircraft Asymptotic evaluation of tlie integral shows tlie drag can be decomposed into three components corresponding to streamwise vorticity and variations in entropy and stagnation enthalpy. These are shown to be related to tlie established engineering concepts of induced drag, wave drag, profile drag and engine power and efficiency. This …

A New Grouping Measure For Evaluation Of Machine-Component Matrices, Hamid Seifoddini, Manocher Djassemi

Industrial Technology and Packaging

The machine-component matrix is the main input to most machine-component grouping models used in cellular manufacturing. A number of measures have been developed for performance evaluation of machine-component grouping algorithms. In this paper, the relationship between these measures and the performance of the corresponding cellular manufacturing system is evaluated and a new grouping measure is developed which is more consistent in predicting the suitability of a manufacturing system for cellular manufacturing.

Sizing Of Header And Flushing Manifolds For Row Crop Drip, Charles M. Burt, Stuart W. Styles

BioResource and Agricultural Engineering

No abstract provided.

Determination Of Iron Colloid Size Distribution In The Presence Of Suspended Cells: Application To Iron Deposition Onto A Biofilm Surface, Waihung Lo, Yarrow M. Nelson, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse

Civil and Environmental Engineering

Transport and deposition of colloidal Fe, Mn and Al oxides play key roles in the cycling of toxic transition metals in aquatic environments because these colloids strongly bind transition metals. Further, attachment of biological cells and biofilm growth on surfaces can indirectly affect toxic metal distribution by influencing the deposition of colloidal oxides to surfaces. To elucidate the mechanisms governing these processes, deposition of colloidal oxides onto surfaces must be evaluated in the presence of suspended and adherent bacterial cells. Both particle size and concentration are expected to influence deposition. An experimental protocol was developed to determine the size distribution …

Status And Needs Assessment: Survey Of Irrigation Districts - Usbr Mid-Pacific Region, Charles M. Burt, Kris O'Connor, Stuart W. Styles, Mike Lehmkuhl, Chad Tienken, Robert Walker

BioResource and Agricultural Engineering

ITRC gathered data from 61 agricultural districts in the U.S. Department of the Interior Bureau of Reclamation's (USBR) Mid-Pacific Region by interviewing irrigation district personnel and studying their Water Conservation Plans. These districts comprise about 90% of the irrigated acreage in the Mid-Pacific Region. Data were analyzed to determine general demographic information, the degree of water delivery flexibility provided to farmers, and the extent of existing and planned district modernization.

Pc Windows Finite Element Modeling Of Landfill Gas Flow, Stephen R. Mull, Robert L. Lang, Samuel A. Vigil, Harold M. Cota

Civil and Environmental Engineering

A two dimensional demonstration program, GAS, has been developed for the solution of landfill gas (LFG) flow problems on a personal computer (PC). The program combines a Windows™ graphical user interface, object oriented programming (OOP) techniques, and finite element modeling (FEM) to demonstrate the practicality of performing LFG flow modeling on the PC. GAS is demonstrated on a sample LFG problem consisting of a landfill, one gas extraction well, the landfill liner, cap, and surrounding soil. Analyses of the program results are performed for successively finer grid resolutions. Element flux imbalance, execution time, and required memory are characterized as a …

Testing Of Concrete Under Closed-Loop Control, Ravindra Gettu, Barzin Mobasher, Sergio Carmona, Daniel C. Jansen

Civil and Environmental Engineering

Closed-loop testing systems provide the ability to directly control the deformation of the loaded specimen. This considerably enhances the precision, stability, and scope of the experiments. Closed-loop machines can be used to determine the stable response of test specimen or structure by monitoring and controlling the physical quantities that are sensitive to its behavior. The importance of the various components of the closed-loop controlled system and the test configuration is reviewed in the paper. The most critical aspect of designing the test is the choice of the controlled variable. With appropriate controlled variables and good system performance, several interesting and …