Engineering Commons^™

California Crop And Soil Evapotranspiration, Charles Burt

BioResource and Agricultural Engineering

The goal of this publication is to provide water users, consultants, water agency personnel, and others throughout California with information that will: (a) help individual water users with irrigation scheduling and system design and (b) help agricultural water agency personnel with water balances and future planning.

The tables in this publication represent the consolidation of results from thousands of annual ET simulations that accounted for crop, rainfall (wet, dry, or “typical”), soil, and irrigation method in each of 13 major ETo zones in California. The annual simulations used daily water balances at the soil surface, crop canopy, and soil root …

An Algorithm Using Length-R Paths To Approximate Subgraph Isomorphism, Fred Depiero, David Krout

Electrical Engineering

The ‘LeRP’ algorithm approximates subgraph isomorphism for attributed graphs based on counts of length-r paths. The algorithm provides a good approximation to the maximal isomorphic subgraph. The basic approach of the LeRP algorithm differs fundamentally from other methods. When comparing structural similarity LeRP uses a neighborhood of nodes that varies in size dynamically. This approach provides sufficient evidence of similarity to permit LeRP to form a node-to-node mapping and can be computed with polynomial effort in the worst-case. Results from over 32,000 simulated cases are reported. We demonstrate that LeRP does not need a high dynamic range of node and …

Telog Pr-31 Water Level Tracker, Stuart W. Styles

BioResource and Agricultural Engineering

The Irrigation Training and Research Center, working under a technical service agreement with the United States Bureau of Reclamation (USBR) Mid-Pacific Region, has undertaken a performance review of advanced electronic water level measurement technologies in irrigation applications. An example is the Telog PR-31 Level Tracker.

Itrc Weir Stick, Stuart W. Styles

BioResource and Agricultural Engineering

The Irrigation Training and Research Center, working under a technical service agreement with the United States Bureau of Reclamation (USBR) Mid-Pacific Region, has developed a new weir rule for open-channel flow rate measurement.

Government Highline Canal – A Win-Win Solution, Charles M. Burt, Stuart W. Styles

BioResource and Agricultural Engineering

The Irrigation Training and Research Center, working under a technical service agreement with the United States Bureau of Reclamation (USBR) Upper Colorado Region, Western Colorado Area Office, performed canal modernization on the Government Highline Canal in the form of automated canal structures, in-system storage, and new operational procedures that could significantly reduce operational spill.

Analysis Of Temperatures At A Municipal Solid Waste Landfill, Nazli Yesiller, James L. Hanson

Civil and Environmental Engineering

A study is conducted to determine the thermal regime within and around a municipal solid waste landfill located in midwestern U.S.A. Spatial distributions of temperatures have been determined over time since 1999 within the waste mass, liner and cover systems, and surrounding subgrade. Seasonal variations, placement of waste, age of waste, depth and location of waste, and available moisture have significant effects on temperatures. Temperatures of wastes at shallow depths, bottom liner systems prior to waste placement, and final cover systems conform to seasonal temperature variations. Steady elevated temperatures are reached with respect to air and ground temperatures at central …

Improving Dsp Performance With A Small Amount Of Field Programmable Logic, John Y. Oliver, Venkatesh Akella

Electrical Engineering

We show a systematic methodology to create DSP + field-programmable logic hybrid architectures by viewing it as a hardware/software codesign problem. This enables an embedded processor architect to evaluate the trade-offs in the increase in die area due to the field programmable logic and the resultant improvement in performance or code size. We demonstrate our methodology with the implementation of a Viterbi decoder. A key result of the paper is that the addition of a field-programmable data alignment unit (FPDAU) between the register-file and the computational blocks provides 15%-22% improvement in the performance of a Viterbi decoder on the state-of-the-art …

Vibration-Based Crack Diagnosis In Rotating Shafts During Acceleration Through Resonance, Jerzy T. Sawicki, Xi Wu, George Y. Baaklini, Andrew L. Gyekenyesi

Mechanical Engineering

The dynamic response of a cracked Jeffcott rotor passing through the critical speed with constant acceleration is investigated analytically and numerically. The nonlinear equations of motion are derived and include a simple hinge model for small cracks and Mayes' modified funciton for deep cracks. The equations of motion are integrated in the rotating coordinate system. The angle between the crack centerline and the shaft vibaiton (whirl) vector is used to determine the clsoing and opening of the crack, allowing one to study the dynamic response with and without the rotor weight dominance. Vibration phase response is used as one of …

The Biomechanical Aspects Of Pedestrian Protection, Krishnakanth Aekbote, Peter Schuster, Sunny Kankanala, Srini Sundararajan, Stephen W. Rouhana

Mechanical Engineering

In this paper a biomechanical basis for pedestrian protection is presented based on reviews of epidemiological and biomechanical studies conducted over the last three decades. Epidemiological studies reveal the nature and cause of pedestrian crashes and injuries sustained in the field. The various factors that influence pedestrian crashes and fatalities such as pedestrian demographics, time and location of crash, type of vehicles involved and their design characteristics, impact speeds, and nature and severity of injuries sustained are covered in the epidemiology section. The biomechanical studies identify the injury mechanisms and the biomechanical tolerances. Several biomechanical studies that attempt to identify …

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 …

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 …

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 …

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 …

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 …

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 …

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.

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.

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.

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 …

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 …

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 …

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.

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 …

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 …

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.