Engineering Commons^™

Schottky Effect At A Metal-Polymer Interface, G. Rikken, David Braun, E. Staring, R. Demandt

Electrical Engineering

We report the observation of the Schottky effect at the interface between a metal and a semiconducting polymer by means of internal photoemission spectroscopy. The bias dependence of the barrier provides information on the electrical properties of the polymer.

State-Of-The-Art: In Polymer Light-Emitting Diodes Neome Polymer Led Mini Symposium (15–17 September 1993, Eindhoven, The Netherlands), David Braun, Adam Brown, Emiel Staring, E. W. Meijer

Electrical Engineering

A symposium focused on recent progress in the field of polymer light-emitting diodes was held in Eindhoven during the period 15–17 September 1993. The following is a brief summary of highlights of the symposium. There will be no published proceedings.

Monolithic Concrete Irrigation Pipe, Charles M. Burt, John M. Wegener

BioResource and Agricultural Engineering

Monolithic concrete pipe (also known as "Cast-in-Place Concrete Pipe" (CIPCP) or Cast-In-Place Pipe (CIPP)) is widely used in some regions for purposes such as storm, sewer, or irrigation pipelines. The earliest use of CIPCP was in 1922 in the Turlock Irrigation District of California. It is reported by The Sierra Group (Sierra, 1991) that there are over 15 million linear feet (4.6 million linear meters) of CIPCP under various applications. Nevertheless, many irrigation engineers, especially outside the U.S., are unaware of CIPCP. Monolithic concrete irrigation pipe is seldom mentioned in irrigation design literature. This paper has been written to familiarize …

Grassland Basin Irrigation And Drainage Study, Stuart W. Styles, Dennis Westcot, Dr. Charles M. Burt, Ross Steensen

BioResource and Agricultural Engineering

This paper summarizes a project that analyzed the district irrigation efficiency for six subareas of the Grassland Basin roughly representing 80,000 acres on the west side of the San Joaquin Valley near Firebaugh, California. The objectives of this project were to: • Determine the district irrigation efficiency for the six subareas. • Update district drainage policies and water reuse. • Update the geographical information system (GIS). • Perform a pre-plant irrigation efficiency analysis. • Establish a relationship between the drainage volumes and the district irrigation efficiency. • Determine the maximum district irrigation efficiency attainable. • Determine the impact of optimizing …

Evaluating Strength & Energy Requirements For Workers Picking Vegetables, R. A. Cavaletto, J. Miles, J. Meyers, J. Mehlschau

BioResource and Agricultural Engineering

The paper discusses the need to obtain field data to evaluate the strength and energy requirements for workers picking a variety of vegetables. This information is central to the evaluation of hazards related to repetitive motion, excessive stress, and fatigue. Results can be used to select activities which should be targeted for future engineering design projects. Preliminary data from a commercial broccoli harvesting operation is included.

Comparison Of The Environmental Effects Of Aerobic And Anaerobic Composting Technologies, Samuel A. Vigil, George Tchobanoglous

Civil and Environmental Engineering

The biological conversion of yard wastes and municipal solid waste by aerobic composting is an established technology. Anaerobic conversion of these wastes is less practiced but is being widely advocated for the next generation of bioconversion systems. Although the operational characteristics of both types of systems is well known, there is a lack of quantifiable data in the literature on the environmental effects of these technologies. It is widely assumed that they are environmentally benign, especially as compared to other processing and conversion technologies such as incineration or mechanical processing. The process microbiology, design, and operational characteristics of aerobic and …

A Preliminary Model For Lot Sizing In Semiconductor Manufacturing, Tali F. Carmon, Steven Nahmias

Industrial and Manufacturing Engineering

No abstract provided.

A Current-Mode Fdnr Circuit Element Using Capacitive Gyrators, Vladimir I. Prodanov, Michael M. Green

Electrical Engineering

A current-mode implementation of a frequency-dependent negative resistance (FDNR) element is presented using a novel capacitive gyrator. This FDNR element lends itself well to the design of low-pass ladder filters and its use will result in a more efficient integrated circuit implementation than filters that simulate floating inductors using resistive gyrators.

Seismic Response Study Of The Us 101/Painter Street Overpass Using Strong Motion Records, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

Abutment stiffnesses are determined directly from the earthquake motions recorded at the US 101/Painter Street Overpass using a simple equilibrium-based approach without finite-element modeling of the structure or the abutment-soil systems. The calculated abutment stiffnesses, which include the effects of soil-structure interaction and nonlinear behavior of the soil, are used to investigate variation of the abutment stiffness with its deformation during the earthquake and torsional motions of the road deck. Also evaluated are the CALTRANS, ASSHTO-83, and ATC- 6 procedures for estimating the abutment stiffness. It is demonstrated that stiffness of the abutment depends significantly on its deformation during the …

Ultrafast Dynamics In Field-Enhanced Saturate Absorbers, J. R. Karin, R. J. Helkey, Dennis J. Derickson, R. Nagarajan, D. S. Allin, J. E. Bowers, R. L. Thornton

Electrical Engineering

Absorption recovery dynamics of GaAs/AlGaAs field-enhanced waveguide saturable absorbers are studied by pump-probe differential transmission measurements. We compare the response of bulk and single quantum well absorbers at different reverse bias levels and pump powers, and find an ultrafast transient in the response, followed by a slower rise before the final recovery. The absorption fully recovers after a few picoseconds, which is an important result for mode-locked lasers.

Error Recovery In Intelligent Robotic Workcells, R. D. Borchelt, Sema E. Alptekin

Industrial and Manufacturing Engineering

This paper focuses on the requirements for achieving automated diagnosis and error recovery in a robotic assembly cell. Untended robust operation is the goal which is discussed, and the use of a knowledge-base oriented diagnostic/control system to support on-line error recovery is advocated. It is proposed that error recovery attempts should be made, not only based on information gathered by system sensors, but also by using additional cell-specific knowledge pertaining to recovery strategies. Recovery attempts are to be made even in the absence of complete diagnosis, in order to gather additional information. A control structure developed to implement this approach …

Dual-Level Approach For Seismic Design Of Asymmetric-Plan Buildings, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

Buildings should be designed to resist moderate ground motion without structural damage and resist intense ground motion with controlled damage. However, most codes do not consider both these requirements explicitly and specify a single design earthquake that generally corresponds to intense ground motion. Investigated in this study is the response of one-story, asymmetric-plan systems designed according to torsional provisions of seismic codes to the two levels of ground motions with the objective of evaluating whether such systems satisfy these requirements. The presented results demonstrate that such systems may not remain elastic during moderate ground motion resulting in structural damage and …

The Importance Of Considering Size Effect Along The Cutting Edge In Predicting The Effective Lead Angle For Turning, William J. Endres, Daniel Waldorf

Industrial and Manufacturing Engineering

The concept of an effective orthogonal cutting edge in turning is considered. The orientation of this edge in the radial-longitudinal plane, as commonly modeled through an effective lead angle, is studied. The methods of effective lead angle prediction used in numerous previously developed force models are plagued with large errors over ranges of process inputs, in particular feed rate and depth of cut. Four previously developed methods of effective lead angle prediction are reviewed and compared to a new method presented here. This new method accounts for the size effect as introduced through the variation in chip thickness along the …

Journal Of Engineering Education Round Table: Reflections On The Grinter Report, James G. Harris, Eugene M. Deloatch, William R. Grogan, Irene C. Peden, John R. Whinnery

Electrical Engineering

The Round Table is a new presentation format for the Journal of Engineering Education. The purpose of the Round Table is to present the comments of several distinguished individuals about a topic as well as their responses to the comments offered by their colleagues. For the initial Journal of Engineering Education Round Table we asked for reflections about the Grinter Report, published in September 1955.

After a brief introduction to the topic of discussion, the invited participants present their views, and, then, respond to the remarks of their colleagues. The goal is two-fold: to present a spectrum of views on …

Ignition And Combustion Properties Of Pulverized Coal Suspended In Laminar Upward Flow Under High Heating Rate Condition, Masayuki Taniguchi, John C. Chen, Kiyoshi Narato, Kazuyuki Ito, Hiroshi Miyadera, Kazuhiko Kudo

Mechanical Engineering

Ignition and combustion behaviors were observed for pulverized coal particles which were suspended in a laminar upward flow and were heated by a single pulse Nd : YAG laser. The surface temperature of the particles was estimated to increase at a rate of about 10⁶K/s. For a bituminous coal, observations with high-speed video revealed that the coal particles ignited heterogeneously 1-2ms after the laser pulse operation and this was followed by the evolution of volatile materials and their combustion in the gas phase. A rate constant of surface oxidation reaction of the bituminous coal at a temperature range …

High Power Edge-Emitting Light Emitting Diodes At 1.5Μ With Extremely Low Back Facet Feedback, J. E. Fouquet, G. R. Trott, W. V. Sorin, M. J. Ludowise, D. M. Braun, Dennis J. Derickson

Electrical Engineering

This paper describes novel semiconductor sources for optical low coherence reflectometry (OLCR), a measurement technique for characterizing device and fiber reflections with high sensitivity and high spatial resolution. Lasers and conventional superluminescent LEDs are not suitable for OLCR because strong reflections from the back facets mask weak reflection signals from the device or fiber under test. Even standard edge emitting LEDs (EELEDs) show significant reflections, which have limited the dynamic range of previous measurements. Low source output powers have also limited sensitivity. In order to obtain high power while minimizing internal reflections, a high single pass gain device is required. …

Explanation Of Timing Jitter Mechanisms In Multisegment Mode-Locked Semiconductor Lasers, Dennis J. Derickson

Electrical Engineering

Multisegment mode-locked semiconductor lasers offer a simple, high performance solution for short pulse generation. Six mode-locking techniques used in multisegment mode-locked semiconductor lasers are shown. This paper concentrates on a theoretical explanation of the timing jitter mechanisms in these lasers with supporting experimental measurements. The analysis covers passive, hybrid, and active mode-locking techniques for both monolithic and external cavity devices. Timing jitter is a very important system consideration for most applications of mode-locked lasers.

Local Needs Implementation For All Programs, James G. Harris, Madeleine M. Johnson, Norm Rogers, Jay Waddell

Electrical Engineering

SYNTHESIS is one of four ex1sting NSF Engineering Education Coalitions (there are apparently plans to add two others this year to bring the total number to six). SYNTHESIS consists of eight universities: Cal Poly, Cornell. Hampton, Iowa State, Southern, Stanford, Tuskgekee, and UC-Berkeley. It has been supported by NSF for over three years, being one of the first two-the other being ECSEL. The other two existing coalitions are GATEVI/AY and SUCCEED. One 9f the main goals of the 'SYNTHESIS coalition is the development of the National Engineering Education Dehvery System (NEEDS). After giving a brief overv1ew of the NEEDS, we …

National Engineering Education Delivery System (Needs), Alice M. Agogino, Sheri Sheppard, Kate Mink, James G. Harris, Lawrence Genalo, Jaya Krishnagopalan, Dave Martin, John Saylor

Electrical Engineering

The Synthesis Coalition, supported by the National Science Foundation and industrial partners, is comprised of the following eight educational institutions: California Polytechnic State University at San Luis Obispo, Comell, Hampton, Iowa State, Southern, Stanford, and Tuskegee Universities, and the University of California at Berkeley (1].

The National Engineering Education Delivery System (NEEDS) is an entirely new courseware development and distribution system which will provide Widespread, rapid, electronic access to an almost arbitrarily large number of diverse instructional modules (2-4). Curricular material in the NEEDS database are organized by a diverse range of indices. Links across disciplines are provided in the …

Set-Up Saving Schemes For Printed Circuit Boards Assembly, Oded Z. Maimon, Ezey M. Dar-El, Tali F. Carmon

Industrial and Manufacturing Engineering

Focusing on a basic printed circuit board (PCB) assembly line configuration characterized by very long set-up times, we examine two scheduling methods that can significantly reduce the set-up. Both methods -the Grouped Set-Up (GSU) method that has been recently introduced in the literature and the Sequence Dependent Scheduling (SDS) method, which has not been studied in this context -are based on component commonality among PCB types. Using the typical traditional scheduling method as a benchmark, the GSU and the SDS methods are compared in terms of three performance measures: line throughput, average work-in-process (WIP) inventory level, and implementation complexity. Guidelines …

Seismic Code Analysis Of Buildings Without Locating Centers Of Rigidity, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

Static force procedures of most building codes require that the lateral earthquake force at each floor level of an asymmetric-plan building be applied eccentrically from the centers of rigidity. To implement such procedures, it seemed necessary in the past to determine the locations of the centers of rigidity, an often confusing and cumbersome process. This paper presents a new approach for code lateral force analysis of asymmetric-plan buildings without locating the centers of rigidity. This procedure combines the results from three static analyses, which can be implemented directly on most commercially available computer programs for analysis of multistory buidings. The …

Numerical Prediction Of Transition Of The F-16 Wing At Supersonic Speeds - Final Report, Russell M. Cummings, Joseph A. Garcia

Aerospace Engineering

No abstract provided.

Vinyl Chloride Biodegradation With Methanotrophic Attached Films, Yarrow M. Nelson, William J. Jewell

Civil and Environmental Engineering

Methanotrophic degradation of vinyl chloride (VC) is investigated using a laboratory-scale methanotrophic attached-film expanded-bed (MAFEB) bioreactor. This study provides a basis for applying a microbial cometabolizing reaction to practical treatment of toxic chlorinated compounds. The MAFEB reactor was operated at 20°C with influent VC concentrations ranging from 1,800 to 9,600 µg/L and bed hydraulic retention times ranging from 3.7 to 7.6 h. VC effluent concentrations during steady continuous operation ranged from 3 to 140 µg/L, with most values less than 26 µg/L, resulting in removal efficiencies of 96.3% to 99.8%. The maximum continuous-flow VC degradation rate observed at 20°C was …

Integration Of Simulation Modeling And Computer Aided Production Management In Computer Integrated Enterprise, Emine Persentili, Sema E. Alptekin

Industrial and Manufacturing Engineering

Designing efficient and integrated manufacturing systems is the first step in attaining computer integrated enterprises (CIE). Integration of planning and implementation phases of manufacturing is essential for taking full advantage of the CIE. In order to design reliable and efficient manufacturing systems, the designers must consider the impacts of planning decisions made by computer aided production management (CAPM) modules on implementations held in manufacturing cells. This paper focuses on two issues. The first issue is importance and necessity of integrating CAPM modules with manufacturing cells. The second issue includes major features of the object-oriented approach and their relevance to our …

A Dynamic Part Assignment Procedure In Machine Cell Formation, Hamid Seifoddini, Manocher Djassemi

Industrial Technology and Packaging

A major contributing factor to the under utilization of machines in cellular manufacturing is the development of long queues in front of some machines in machine cells. This paper presents a procedure which identifies such machines and redistributes their loads to alternative machines whenever feasible.

Transient Flowmeter Calibration Facility, Paul J. Lefebvre, William W. Durgin

Office of the Provost Scholarship

An apparatus for defining the free surface of a moving column of a fluid in a vertical pipe to enhance the accuracy of measurements of transient rate of flow of the fluid using electromagnetic flowmeter is described. It provides a neutrally buoyant plug which stays in contact with the free surface of the column of the fluid at all times and thus defines the free surface of the fluid moving in the vertical pipe accurately and reduces the oscillations of the free surface of the fluid.

Advanced Aeronatics Design: Project Based Engineering Education At Wpi, D. J. Olinger, William W. Durgin, Andreas N. Alexandrou

Office of the Provost Scholarship

One element of WPI's project-based curriculum is its interdisciplinary Advanced Aeronautics Design Program. Students participating in the program are involved in the design, construction, and flight testing of non-traditional aircraft such as an ultralight solar-powered vehicle, microwave-powered long endurance aircraft, or a flying oblique wing. The WPI project philosophy and character are described and illustrated using examples from the AAD program.

Gis Utilization For Analysis Of District Drainage Water Recycling, Charles M. Burt, Robert E. Walker

BioResource and Agricultural Engineering

An ARC-INFO GIS system was used to identify physical drainage facilities in a 32,000 ha area of the San Joaquin Valley of California. Once the drainage facilities and linkages were established, it was possible to characterize the strategies used by various irrigation districts to control drainage outflows to the San Joaquin River. The motivation behind the study was the reduction of salt and selenium flows, via agricultural drainage, into the River.

Irrigation-Canal - Simulation Model Usage, Charles M. Burt, Gregory Gartrell

BioResource and Agricultural Engineering

Unsteady canal-simulation model usage requires serious investments of time and personnel. The reasons for deciding to invest in a model, as well as reasons not to invest, are discussed. For most cases, it is better to invest in the improvement of an existing model than the writing of a new model. Many excellent models are available, although very few can be considered user-friendly for the average design engineer. Unsteady flow-simulation models are not recommended for real-time control, but are key tools for the study of various control scenarios. Canal models can simulate an actual canal, but the user must input …

Cal Poly Model Canal, John B. Parrish, Iii, Charles M. Burt

BioResource and Agricultural Engineering

The Cal Poly Model Canal, located at the Water Delivery Facility. Irrigation Training and Research Center, California Polytechnic State University, San Luis Obispo, Calif., was built to accommodate the study and promotion of automated downstream control. Being a large, fully functional scale model of a canal, it was used to collect data for use by the Irrigation Canal System Hydraulic Modeling Task Committee of the ASCE Irrigation and Drainage Division. The data was used by Task Committee members to help evaluate numerical models for simulation of unsteady free-surface flow. The Model Canal and the collected data are discussed. This paper …