Engineering Commons^™

Travelling Wave Electrode Optimization For High Speed Electro-Optic Modulators Using The Fourier Series Method, W. Boyu, X. Guangjun, Xiaomin Jin

Electrical Engineering

The performance of Z-cut Mach-Zehnder high speed LiNbO₃ amplitude modulators with a CPW traveling wave electrode, has been analyzed and optimally designed in detail by the Fourier series method. The effect of electrode and buffer layer thickness on the electric field distribution in the substract, effective micro- wave refractive index and characteristic impedance of CPW electrode, are discussed. Calculation shows that increasing the thickness of the electrode and SiO₂ buffer layer can improve the phase velocity mismatch between electric and optical waves, and the drive power required by the modulator with thin buffer layer and thick electrode is …

Estimating The Payback For An Electrical Vfd (Variable Frequency Drive) Application In A Pumping Plant Which Presently Spills Excess Pumpage, Charles M. Burt

BioResource and Agricultural Engineering

This report includes equations and tips for pump selection criteria and estimating the annual KW-hr savings for a VFD installation, including the maximum potential savings and the approximate amount of KW-hr that would have been consumed if one pump had been converted to VFD.

Numerical Design Of Advanced Multi-Element Airfoils, Donovan L. Mathias, Russell M. Cummings

Aerospace Engineering

The current study extends the application of computational fluid dynamics to three-dimensional high-lift systems. Structured, overset grids are used in conjunction with an incompressible Navier-Stokes flow solver to investigate flow over a two-element high-lift configuration. The computations were run in a fully turbulent mode using the one-equation Baldwin-Barth turbulence model. The geometry consisted of an unswept wing which spanned a wind tunnel test section. Flows over full and half-span Fowler flap configurations were computed. Grid resolution issues were investigated in two-dimensional studies of the flapped airfoil. Results of the full-span flap wing agreed well with experimental data and verified the …

Analysis Of Efficiency Measures For Block Diagonal Machine-Component Charts, Hamid Seifoddini, Manocher Djassemi

Industrial Technology and Packaging

Group efficiency measures have been developed to evaluate machine-component charts for the formation of cellular manufacturing systems. In this paper the existing grouping efficiency measures will be evaluated by determining the relationship between the values of a grouping efficiency measure and the performance of the corresponding cellular manufacturing system.

Computational Analysis Of Forebody Tangential Slot Blowing, Ken Gee, Roxana M. Agosta-Greenman, Yehia M. Rizk, Lewis B. Schiff, Russell M. Cummings

Aerospace Engineering

No abstract provided.

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 …

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 …

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.

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.

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 …

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 …

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 …

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 …