Engineering Commons^™

Seismic Response Study Of Asymmetric Systems With Linear And Nonlinear Fluid Viscous Dampers, Rakesh K. Goel

Civil and Environmental Engineering

This investigation is concerned with application of nonlinear fluid viscous dampers for asymmetric-plan systems. For this purpose, the behavior of nonlinear fluid viscous dampers is summarized first followed by the effects of damper nonlinearity on seismic response of asymmetric systems. It is shown that the peak force in nonlinear damper tends to be smaller compared to linear damper. However, this is true only for values of V / ů_o less that a certain threshold value; for larger values of V / ů_o, the force in nonlinear damper may become larger· than that in the linear damper. While …

Buffer Interference Architecture, Vladimir I. Prodanov

Electrical Engineering

An up to 3× breakdown voltage tristate capable integrated circuit CMOS buffer includes a level shifter circuit and a driver circuit. The driver stage includes a series connected n-channel and p-channel cascode stacks, each including at least three transistors. Dynamic gate biasing is provided for the third n-channel and p-channel cascode transistors to prevent voltage overstress of the cascode transistors. The level shifter circuit includes at least one pseudo N-MOS inverter including an input transistor, a protective cascode stack including at least one n-channel cascode transistor, and a load transistor. The level shifter provides at least one voltage shifted input …

Student Perceptions Of Institutional And Instructor Based Techniques For Dealing With Academic Dishonesty, Donald D. Carpenter, Trevor S. Harding, Susan M. Montgomery, Nicholas H. Steneck, Eric Dey

Materials Engineering

Research suggests that a large percentage of engineering students engage in some form of academic dishonesty. To investigate this very serious concern, the authors have undertaken a research project on the Perceptions and Attitudes toward Cheating among Engineering Students (PACES). The premise of this research is that a combination of pressures, rather than malicious motivations, account for most student cheating. This paper focuses on a portion of the PACES survey; student opinions on what actions might prevent cheating. The authors examined data collected from approximately 350 engineering and pre-engineering undergraduate students at 5 institutions. In the survey, the students were …

A Comparison Of The Role Of Academic Dishonesty Policies Of Several Colleges On The Cheating Behavior Of Engineering And Pre-Engineering Students, Trevor S. Harding, Donald D. Carpenter, Susan M. Montgomery, Nicholas H. Steneck

Materials Engineering

While universities take a variety of approaches in dealing with academic dishonesty, current evidence suggests that institutions with honor codes have a significantly lower level of self-reported cheating as compared to nonhonor code institutions. This paper focuses on five institutions and their effectiveness in dealing with cheating, specifically among engineering or pre-engineering students. The authors' goal is to provide greater understanding of what institutional approaches appear to be most effective in minimizing cheating among this specific sub-group. The paper presents a predictive model of the extent of cheating among engineering students at these institutions using a variety of variables, including …

Illuminating Electronics Problem Solving With The Cal Poly Mohat Technique, David Braun, Fred W. Depiero, Michael Borland

Electrical Engineering

This paper describes a Cal Poly version of circuit analysis to assist both students and instructors. The primary focus of the technique is helping students perform hand analysis, particularly the type of hand analysis that clarifies the student’s understanding of circuit operation in a manner that can benefit subsequent design decisions. The technique nicely complements graphical solution techniques such as load-line analyses and computer aided circuit simulation. MoHAT, an abbreviation of Model-Hypothesize-Analyze-Test, provides students with a roadmap to use, when analyzing even relatively complex circuits containing diodes and transistors. This paper emphasizes the pedagogy of MoHAT and describes a web-based …

The Wpi/Goddard Space Flight Center Projects Program, Fred J. Looft, William W. Durgin

Office of the Provost Scholarship

The WP/IGSFC (Goddard Space Flight Center) Projects Program is an off-campus, multi-disciplinary opportunity for students to complete their capstone design project requirement during 10 weeks of on-site project work. Students accepted into this program are required to spend one term in a project preparation course where they carry out background research, interact with their project mentor(s) at the space center, and write a detailed project proposal. At the completion of the preparation course and several weeks before the start of the following academic year, the students relocate to the Washington area and work full time for ten weeks on their …

Damage Accumulation Under Repeated Reverse Stressing Of Sn-Ag Solder Joints, Katherine C. Chen, A. Telang, J. G. Lee, K. N. Subramanian

Materials Engineering

To better understand the effect of repeated reverse stress in solder joints, a new testing method was developed. Tin-silver solder joints were fabricated, constrained between Cu blocks, and then subjected to repeated shear loading in a tensile tester. Constant strain amplitudes were applied to simulate service conditions. However, large loads were used to accelerate the damage accumulation. Microstructural features of the damage were very similar to those found with studies on thermomechanical fatigue (TMF) of small, single shear lap samples. Concentrated-shear banding or striations were observed to form along Sn dendrites. The load behavior of the solder with each cycle …

Focus On The Job In Hand: When Usb 2.0 Technology Is Employed In Test And Measurement Signal Analyzer Hardware, Life Can Become So Much More Simple, Charles Birdsong, Dave Galyardt, James Zhuge

Mechanical Engineering

No abstract provided.

Benchmarking Of Flexibility And Needs 2002: Survey Of Non-Federal Irrigation Districts (California Department Of Water Resources), Stuart W. Styles, Daniel Howes

BioResource and Agricultural Engineering

ITRC interviewed irrigation district personnel from 17 agricultural districts throughout California. Data were analyzed to determine the degree of water delivery flexibility provided to farmers and the extent of existing and planned district modernization. This report did not include irrigation districts with long-term federal contracts.

The Impact Of Variations In Membrane Capacitance On The Detected Neural-Electronic Signal, Robert B. Szlavik

Biomedical Engineering

There have been various theoretical and experimental studies presented in the literature that focus on interfacing neurons with discrete electronic devices such as transistors. The demonstrated lack of reproducible fidelity of the nerve cell action potential at the device junction would make it impractical to implement these devices in any neural prosthetic application where reliable detection of the action potential was a pre-requisite. In this study, the impact of typical variations in membrane capacitance on the detected neural signal is investigated.

Some Observed Queue Discharge Features At A Freeway Bottleneck Downstream Of A Merge, Robert L. Bertini, Michael J. Cassidy

Civil and Environmental Engineering

Details of traffic evolution were studied upstream and downstream of a freeway bottleneck located near a busy on-ramp. It is shown that on certain days the bottleneck became active upon dissipation of a queue emanating from somewhere further downstream. On such occasions, the bottleneck occurred at a fixed location, approximately one kilometer downstream of the merge. Notably, even after the dissipation of a downstream queue, the discharge flows in the active bottleneck were nearly constant, since the cumulative counts never deviated much from a linear trend. The average bottleneck discharge flows were also reproducible from day to day. The diagnostic …

Educating Engineering Students In Entrepreneurship, William W. Durgin, Donald N. Zwiep

Office of the Provost Scholarship

Since it’s founding in 1865, the faculty, students, and alumni of Worcester Polytechnic Institute have been responsible for the establishment of nearly all the manufacturing industry in the region. Beginning with the Norton Company, a world-wide abrasives manufacturer now owned by Saint Gobain, to recent biotechnology companies, they have combined confidence, innovation, and resourcefulness to continuously accomplish what is now referred to as technology transfer to form start-up companies. By following the historical development of these firms, we seek to determine some of the traits and environmental factors that have fostered the continual entrepreneurial success of the founders.

Worcester Polytechnic …

Fatigue Thresholds Of Cracks Resulting From Impact Damage To Γ-Tial, Trevor S. Harding, J. Wayne Jones

Materials Engineering

Significant research has been conducted in recent years on the γ-based titanium aluminide alloys. The low density of γ-TiAl relative to current nickel-based superalloys, has made it an attractive candidate for use in the low-pressure turbine blades of gas turbine engines . In addition to weight savings, the lower density leads to higher specific stiffness and good high temperature strength retention [1, 2 and 3]. However, the ordered crystal structure, typical of intermetallics, leads to inherently low room temperature ductility and fracture toughness. This raises serious concerns about the ability of this material to resist the formation of cracks at …

Impact Of Soil Type And Compaction Conditions On Soil Water Characteristic, C. J. Miller, N. Yesiller, K. Yaldo, S. Merayyan

Civil and Environmental Engineering

Tests were conducted to determine the variation of water content and pore water suction for compacted clayey soils. The soils had varying amounts of clay fraction with plasticities ranging from low to high plasticity. The unsaturated soil behavior was investigated for six conditions, covering a range of compactive efforts and water contents. The experimental data were fit to four commonly used models for the water content-pore water suction relationship. Each model provided a satisfactory fit to the experimental data. However, the individual parameters obtained from the curve fits varied significantly between models. The soil water characteristic curves (SWCCs) were more …

Stability And Heat Transfer Characteristics Of Condensing Films, James C. Hermanson, Peder C. Pedersen, Jeffrey S. Allen, M. A. Shear, Z. Q. Chen, Andreas N. Alexandrou, William W. Durgin

Office of the Provost Scholarship

No abstract provided.

Water Delivery Service As A Determinant Of Irrigation Project Performance, Stuart W. Styles, M. A. Marino

BioResource and Agricultural Engineering

Performance of an irrigation system is represented by its measured levels of achievement in terms of one or several parameters that are chosen as indicators of the system’s goals. The purpose of this paper is to utilize and refine a set of evaluation indicators that can be used to describe the irrigation performance for sixteen international irrigation projects in less-developed countries. The irrigation performance of many international irrigation projects in less-developed countries has been reported as poor. The cause of the poor irrigation performance has been blamed on technical, financial, managerial, social, and/or institutional causes. This study is specifically designed …

Case Study: Installation Of Canal Control Structures On The Government Highline Canal, Ram Dhan Khalsa, Stuart W. Styles, Charles M. Burt, Bob Norman

BioResource and Agricultural Engineering

The Government Highline Canal Modernization Study was completed in April 2000 to evaluate options for reducing the flow rate requirement of the Government Highline Canal in order to increase the water supply in the “15-Mile Reach” of the Colorado River, thereby helping sustain habitat for fish species identified as endangered. The intent was to develop a design for which Colorado River diversions could be better matched to on-farm demands. It was determined that canal modernization, in the form of automated canal structures, in-system storage, and new operational procedures could significantly reduce operational spill. A systematic evaluation of the existing canal …

Modernizing Irrigational Facilities At Sutter Mutual Water Company: A Case Study, Frederick F. Schantz, Stuart W. Styles, Beau J. Freeman, Charles M. Burt, Doughlas Stevens

BioResource and Agricultural Engineering

In 1999 Sutter Mutual Water Company (SMWC) began an effort to modernize its water-distribution system in an attempt to reduce operation and maintenance costs and conserve water and power resources. The primary technical support was provided by professionals from the Irrigation Training and Research Center (ITRC), California Polytechnic State University (Cal Poly), San Luis Obispo. Additional technical expertise was provided by Concepts in Controls of Visalia, California and Wilson Pumps of Woodland, California. This modernization project was partially funded by the United States Bureau of Reclamation (USBR), Mid-Pacific Region, Northern Area Office, though a Field Services Program Grant and technical …

Glenn-Colusa Irrigation District Flow Monitoring Program, Dennis Perkins, Stuart W. Styles, Marcus Y. Yasutake

BioResource and Agricultural Engineering

In 1996, the United States Bureau of Reclamation (USBR), Mid-Pacific Region, Northern California Area Office began the Willows Flow Monitoring Program. The program objective was to monitor, in near real-time, 85% of the Sacramento River Diversions from Shasta Dam to Sacramento. Several site visits were conducted to the District and their diversion points along the Sacramento River by USBR and Irrigation Training and Research Center (ITRC) staff from California Polytechnic state University (Cal Poly), San Luis Obispo. One of the sites identified for flow monitoring was the Glen-Colusa Irrigation District (GCID) canal at the Stoney Creek Siphon. At question was …

Electric Load Shifting In Irrigation Districts - California's Program, Charles M. Burt, Ricardo Amón, Darren Cordova

BioResource and Agricultural Engineering

During the 2000-2001 winter, California experienced a severe imbalance in electricity supply and demand that resulted in blackouts and brownouts. The state legislature initiated a number of emergency programs, one of which (Senate Bill 5x) was targeted for irrigation districts. The primary goal of SB 5x is to reduce peak period electricity demand. The California Energy Commission (CEC), acting under authority of Section 5(b) of the legislation, developed the "Agricultural Peak Load Reduction Program". The program was announced on June 1, 2001, and Cal Poly ITRC administers the irrigation district portion of the program for CEC. During the first 9 …

Advances In Plc-Based Canal Automation, Charles M. Burt, Xianshu Piao

BioResource and Agricultural Engineering

A short history of canal automation is given. PLC-based canal automation is relatively new. Advances in PLC-based canal automation are listed. Also listed are some of the remaining challenges. Recent advances have been made in understanding unsteady flow simulation procedures, the form of the control algorithms used, the tuning procedures for these control algorithms, and the field programming of the algorithms into PLCs. The experiences of the Cal Poly Irrigation Training and Research Center (ITRC) in automating a variety of canals with upstream and downstream control are given.

Breaking The Technology Barriers Imposed By Cast-In Place Concrete Pipe In Irrigation Districts: Case Study Of South San Joaquin Irrigation District, Charles M. Burt, Michael B. Gilton, Kevin Johnson, Keith Crowe

BioResource and Agricultural Engineering

South San Joaquin Irrigation District (SSJID) in Manteca, California, is beginning an ambitious modernization program to increase its water delivery flexibility. The district has over 200 miles of 30-60 inch cast-in-place (CIP) concrete pipeline that currently allow for little flexibility. SSJID will install four reinforced concrete interceptor pipelines and regulating reservoirs to redistribute water among the CIP pipelines and provide improved flexibility. The district's goal is to improve efficiency and encourage farmers with pressurized irrigation systems to shift from well water to surface water.

A Method For Thermodynamic Work Potential Analysis Of Aircraft Engines, Robert Mcdonald

Aerospace Engineering

The objective of this paper is to provide a tool to facilitate the application of thermodynamic work potential methods to aircraft and engine analysis. This starts with a discussion of the theoretical background underlying these methods, which is then used to derive various equations useful for thermodynamic analysis of aircraft engines. The work potential analysis method is implemented in the form of a set of working charts and tables than can be used to graphically evaluate work potential stored in high-enthalpy gas. The range of validity for these charts is 300 to 36,000 °R, pressures between 0.01 and 100 atm, …

Closure To "Flap Gate Design For Automatic Upstream Canal Water Level Control", Charles M. Burt, Russdon Angold, Mike Lehmkuhl, Stuart Styles

BioResource and Agricultural Engineering

No abstract provided.

Semiconducting Polymer Leds, David Braun

Electrical Engineering

Technologies based on organic semiconductors may answer the increasing demands that consumers make in the areas of large-area electronics, lightweight displays, and portable computing. Advances in scientific understanding, technology, and device performance have occurred particularly rapidly in the area of polymer light-emitting diodes (LEDs). Material properties and economic considerations suggest that polymer LEDs are the devices most likely to win the race to applications that produce light on inorganic substrates such as glass and silicon, as well as plastic substrates.
The field of semiconducting polymers has its root in the 1977 discovery of the semiconducting properties of polyacetylene¹. …

Fast Landmark-Based Registration Via Deterministic And Efficient Processing, Some Preliminary Results, Fred W. Depiero

Electrical Engineering

Preliminary results of a new method for range view registration are presented. The method incorporates the LeRP Algorithm, which is a deterministic means to approximate subgraph isomorphisms. Graphs are formed that describe salient scene features. Graph matching then provides the scene-to-scene correspondence necessary for registration. A graphical representation is invariant with respect to sensor standoff. Test results from real and synthetic images indicate that a reasonable tradeoff between speed and accuracy is achievable. A mean rotational error of ~1 degree was found for a variety of test cases. Mean compute times were found to be better than 2 Hz, with …

Suggestions For Establishing Centers For Engineering Education, Trevor S. Harding, Cynthia J. Finelli

Materials Engineering

No abstract provided.

P.A.C.E.S. - A Study On Academic Integrity Among Engineering Undergraduates (Preliminary Conclusions), Donald D. Carpenter, Trevor S. Harding, Susan M. Montgomery, Nicholas H. Steneck

Materials Engineering

Student academic dishonesty, commonly referred to as cheating, has become a serious problem at institutions of higher education. This is particularly true of engineering students who, according to previous research, are among the most likely to cheat in college. To investigate this concern, the authors have undertaken a research project on the Perceptions and Attitudes toward Cheating among Engineering Students (P.A.C.E.S.). The premise of this research is that a combination of pressures, rather than malicious motivations, account for most student cheating. The P.A.C.E.S study consists of a seven page, self-reported survey that investigates: (1) student definitions of academic dishonesty; (2) …

Integrating Manufacturing, Design And Teamwork Into A Materials And Process Selection Course, Trevor S. Harding, G. Y. Lai, B. L. Tuttle, C. V. White

Materials Engineering

No abstract provided.

Estimation Of Wind Load On Structures, Soheil Saadat, Fuh-Gwo Yuan, Mohammad N. Noori, Gregory D. Buckner

Office of the Dean (CENG) Scholarship

Accurate spatial and temporal estimation of wind loads on structures plays an important role in the design and construction of buildings in coastal regions and open terrains. The common approach to this problem is using codes and standards obtained from wind-tunnel tests on isolated structures. The use of artificial neural networks for finding specific patterns in data obtained from wind-tunnel and field tests has been reported in the literature. In this study localized radial basis functions neural networks are proposed and successfully used for estimation of wind loads on a three-story shear building using a state-space model of the structure.