Engineering Commons^™

A Psychological Perspective On Service Segmentation Models: The Significance Of Accounting For Consumers' Perceptions Of Waiting And Service, Ziv Carmon, J. George Shanthikumar, Tali F. Carmon

Industrial and Manufacturing Engineering

We examine how service should be divided and scheduled when it can be provided in multiple separate segments. We analyze variants of this problem using a model with a conventional function describing the waiting cost, that is modified to account for some aspects of the psychological cost of waiting in line. We show that consideration of the psychological cost can result in prescriptions that are inconsistent with the common wisdom of queuing theorists derived according to the conventional approach (e.g., equal load assignments). More generally, our intention in this paper is to illustrate that aspects of the psychological cost of …

Irrigation Water Conservation - Benefits And Tradeoffs, Charles M. Burt

BioResource and Agricultural Engineering

Water conservation must be examined within the context of a water balance for a zone of specified boundaries. On-farm conservation may not result in basin conservation, and may actually damage water supplies within the basin, especially if groundwater supplies dwindle. Conservation must also take place with recognition of water rights, and therefore concepts such as Irrigation Efficiency and Irrigation Sagacity must be well understood. Because of the diversity of hydrology, there is no single menu of water management improvements which are applicable in all cases. In the future, more emphasis will be placed upon improving crop yields with a given …

Essential Water Delivery Policies For Modern On-Farm Irrigation Management, Charles M. Burt

BioResource and Agricultural Engineering

Successful on‐farm irrigation scheduling requires that water delivery projects adopt a service concept, and that water deliveries be made with a high degree of reliability. An arranged delivery schedule and seasonal volumetric allocations are additional requirements. Until these conditions are met, attempts to implement modem on‐farm irrigation scheduling techniques to maximize water use efficiency and yields will be only partially successful.

Guidelines For Establishing Irrigation Scheduling Policies, Charles M. Burt

BioResource and Agricultural Engineering

Successful on-farm irrigation scheduling requires that water delivery projects adopt a service concept, and that water deliveries be made with a high degree of reliability. An arranged delivery schedule and seasonal volumetric allocations are additional requirements. Until these conditions are met, attempts to implement modern on-farm irrigation scheduling techniques to maximize water use efficiency, and to maximize yields will be only partially successful.

A Simulation Study Of Quality Index In Machine-Component Grouping, Hamid Seifoddini, Manocher Djassemi

Industrial Technology and Packaging

Simulation modeling is employed to determine the effectiveness of quality index in screening machine-part matrices for the development of cellular manufacturing systems.

Identification And Quantification Of Efficiency And Uniformity Components, Charles M. Burt, Albert J. Clemmens, Kenneth H. Solomon

BioResource and Agricultural Engineering

Proper usage of irrigation performance indicators such as uniformity and efficiency require standardized definitions and equations, specification of vertical and horizontal boundaries, inclusion of all pertinent components, and accurate measurement and estimation of those components. The quantification of some critical components is a challenge, and errors always exist.

Biquad Gm-C Structures Which Use Double-Output Transconductors, Vladimir I. Prodanov, Michael M. Green

Electrical Engineering

Two Gm-C biquad structures are derived. They use only two grounded capacitors and three transconductors, two of which have double-outputs. The realization of the double-output transconductors is discussed. It is shown that only two additional transistors are needed to convert a single-output transconductor to a double-output one suitable for implementation of the proposed structures. HSPICE simulations and experimental results of a 5-th order inverse Gaussian filter using the proposed biquad structures are given.

Design Of A Structured Light Sensor For In Situ Calibration, Fred W. Depiero, Reid L. Kress

Electrical Engineering

This paper highlights a ranging sensor that can be calibrated at standoffs of 1 to 3 feet with a depth of field of ≈ 1 ft. Tests at a 16" standoff have produced a 0.004 inch standard deviation in height measurement errors. The data density and field of view are programmable. The sensor is positioned robotically, allowing it to provide accurate, short-range measurements prior to manipulation tasks. The sensor head is relatively inexpensive (≈ $10k) and is designed for in situ calibration. This approach is intended to allow replacement components to be installed, calibrated, and validated without decontamination. Calibration, validation …

Fertigation - The Next Frontier, Charles M. Burt

BioResource and Agricultural Engineering

Just as irrigation dealers presently should specify pressure relief valves and air vents on all pipelined irrigation systems, future irrigation designs will incorporate a new generation of FERTIGATION (fertilization through the irrigation system) hardware. And farmers will use sophisticated techniques to monitor plant nutrient status and to determine the proper level of nutrients to spoon feed through fertigation.

Lead Distribution In A Simulated Aquatic Environment: Effects Of Bacterial Biofilms And Iron Oxide, Yarrow M. Nelson, Waihung Lo, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse

Civil and Environmental Engineering

Biofilms influence the transport and fate of heavy metals in aquatic environments both directly by adsorption and complexation reactions and indirectly via interactions with oxides of iron and manganese. These reactions were investigated by introducing lead into a continuous-flow biofilm reactor that was designed to simulate conditions in a flowing freshwater aquatic environment. The reactor provided controlled conditions, and use of a chemically-defined growth medium allowed calculation of lead speciation with a chemical equilibrium program (MINEQL). Pseudomonas cepacia was employed as a test cell strain because of its ability to grow and form biofilms in the defined medium. This bacterium …

Circulation Measurements About A Rapidly Pitching Airfoil Using An Ultrasonic System, F. J. Weber, Jr., William W. Durgin, H. Johari

Office of the Provost Scholarship

An ultrasonic system was developed to measure the circulation about a sinusoidally pitching NACA 4418 airfoil. The system consisted of two opposing ultrasonic ranging modules arranged such that the differences between the sound propagation times in opposite directions could be related to the instantaneous circulation. For the stationary airfoil, the measured lift coefficient was within 5% of the tabulated data while the observed stall angle was 2° less than the tabulated value. Measured hysteresis loops verified the applicability of the ultrasonic system to the dynamic stall problem. Measured maximum lift coefficients increased linearly with reduced frequency up to a value …

Development Of A Graduate Integrated Waste Management Course Using The Case Study Approach, Samuel A. Vigil

Civil and Environmental Engineering

Solid waste management is an integral part of the environmental engineering profession. At California Polytechnic State University (Cal Poly), solid waste management is taught as a required course in an undergraduate environmental engineering curriculum. The undergraduate course is described in Reference 1. This paper discusses the development of a graduate level integrated waste management course entitled "Resource and Energy Recovery from Waste", which uses a case study approach. The course focuses on resource and energy recovery technologies including composting, unit operations of resource recovery, recycling, and thermal waste conversion including combustion and gasification. The bioconversion of wastes in landfills and …

Effects Of Hydrogen On Inp Light-Emitting Devices Etched In A Methane-Hydrogen Environment, Patricia Beck, Dennis J. Derickson, Forrest Kellert, Tim Bagwell

Electrical Engineering

Research has been conducted on the physical damage and hydrogenation effects during RF plasma exposure and epitaxial growth in the III-V material system. Device consequences of this damage or chemical alteration have received less attention, particularly in active light emitting devices. This paper discusses these effects for lasers and edge emitting light-emitting diodes (EELEDs) which use a ridge waveguide structure. By using analysis techniques such as SIMS we have concluded that methane-hydrogen reactive ion etching of InP induces hydrogen levels in an active device which are high enough to significantly alter the device properties. The decrease in light output is …

Supersonic, Turbulent Flow Computation And Drag Optimization For Axisymmetric Afterbodies, Russell M. Cummings, H. T. Yang, Y. H. Oh

Aerospace Engineering

The compressible, turbulent flow about an axisymmetric body was numerically studied using the MacCormack unsplit explicit algorithm applied to the mass-average Navier-Stokes equations solved in conjunction with the k-ε turbulence model of Jones and Launder. Numerical predictions of total body drag (pressure drag, skin friction drag, and base drag) were made for an axisymmetric body six diameters in length, with and without a boattail. Surface pressures and viscous layer profiles are compared with available wind tunnel data and are found to be in good agreement for both geometries. The Golden Section optimization method was used to optimize the body …

Application Of Macro Material Flow Modeling To The Decision Making Process For Integrated Waste Management Systems, Samuel A. Vigil, Gregory M. Holter

Civil and Environmental Engineering

Computer models have been used for almost a decade to model and analyze various aspects of solid waste management. Commercially available models exist for estimating the capital and operating costs of landfills, waste-to-energy facilities and compost systems and for optimizing system performance along a single dimension (e.g. cost or transportation distance).

An alternative to the use of currently available models is the more flexible macro material flow modeling approach in which a macro scale or regional level approach is taken. Waste materials are tracked through the complete integrated waste management cycle from generation through recycling and reuse, and finally to …

Visible Light Emitting Diodes Fabricated From Soluble Semiconducting Polymers, Alan J. Heeger, David Braun

Electrical Engineering

Visible light LEDs are produced having a layer of conjugated polymer which is cast directly from solution or formed as a gel-processed admixture with a carrier polymer. The LEDs can be formed so as to emit polarized light.

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

Civil and Environmental Engineering

No abstract provided.

Electroluminescence And Photoluminescene Efficiency Of Poly(P-Phenylenevinylene) Deriatives, E. Staring, R. Demandt, David Braun, G. Rikken, Y. Kessener, A. Venhuizen, M. Van Knippenberg, M. Bouwmans

Electrical Engineering

Alkoxy, alkyl, and cyano derivatives of poly(p-phenylenevinylene) [PPV] are used as the emissive layers in light-emitting diodes [LEDs] to obtain luminescence from red to blue. We present the luminescence efficiency for these soluble PPV derivatives. comparing the photoluminescence [PL] yields with the electroluminescence [EL] yields. PL efficiency increases with the fraction of non-conjugated units. EL efficiency depends not only on the radiative recombination efficiency of the emitting material but also on carrier transport to and within the material. Efforts to improve the efficiency and long term stability of these polymer LEDs are challenged by efficient and balanced carrier …

Delano-Earlimart Irrigation District: Variable Frequency Drive Study, Charles M. Burt

BioResource and Agricultural Engineering

This report was conducted to study the pump station operation at Delano-Earlimart Irrigation District (DEID) after the installation of a variable frequency drive (VFD) control. The district is currently involved with the California Energy Commission's low-interest loan program for the installation of VFD units on their pump stations near Delano, California. Delano-Earlimart Irrigation District is a special water district organized under Division 11 of the California Water Code and encompasses 56,500 acres in Southern Tulare County and Northern Kern County. DEID has 18 individual pumping stations. DEID installed VFDs on key pumps at three different plants (D-3, D-12, and D-14).

Observation Of Laser Ignition And Combustion Of Pulverized Coals, John C. Chen, Masayuki Taniguchi, Kazuyuki Ito

Mechanical Engineering

Direct observation of pulsed-laser ignition and combustion of pulverized coals with a high speed video has been made. A dilute stream of particles was dropped into a laminar, upward-flow wind tunnel with a quartz test section. The gas stream was not preheated. A single pulse from a Nd:YAG laser was focused through the tunnel and ignited several particles. The transparent test section and cool walls allowed for optical detection of the reaction sequence. The ignition and combustion behaviours of amorphous carbon spheres and an anthracite were as expected for heterogeneous ignition and reaction. Surprisingly, the reaction of a high volatile …

Evidence Of Heterogeneous Substructure Development During Primary Creep Of Ti-6al-2sn-4zr-2mo, R. W. Hayes, Cecil Rhodes, Blair London

Materials Engineering

No Abstract.

Video Technologies For Roadway Surveillance And Automated Detection, C. Arthur Maccarley, Leonard Ponce

Electrical Engineering

Closed circuit television (CCTV) systems deployed on roadway networks are believed to be among the best mechanisms for providing useful, reliable information for effective traffic management. Video images may be displayed and viewed directly by traffic management personnel for surveillance purposes, or may be processed electronically for detection of traffic metrics such as average vehicle speed, flow volume, and traffic density.

This paper summarizes the current state-of-the art in video imaging and video signal processing technology for traffic surveillance and electronic detection. Technical considerations relevant to the selection of video cameras and computer vision hardware and software for this application …

Optimization Of Expanded Polypropylene Foam Coring To Improve Bumper Foam Core Energy Absorbing Capability, Gregory Frederick, Gregory A. Kaepp, Conrad M. Kudelko, Peter J. Schuster, Friedrich Domas, Udo G. Haardt, Werner Lenz

Mechanical Engineering

To design a cost, weight, and energy efficient bumper foam energy absorber, it is important to consider optimizing the shape of coring employed in the design of the system. In this paper, a number of foam coring patterns are studied by both empirical and analytical methods. The size and shape of proposed core designs are studied in detail with consideration given to several different densities of expanded polypropylene (EPP) foam. Using the finite element method of structural analysis, it is possible to have an inside look at the stress distribution during deformation of foam structures. An optimization study using the …

Response Of Ideally Controlled Canals To Downstream Withdrawals, Charles M. Burt, T. S. Strelkoff, J. L. Deltour

BioResource and Agricultural Engineering

No abstract provided.

Merits Of The Production Volume Based Similarity Coefficient In Machine Cell Formation, Hamid Seifoddini, Manocher Djassemi

Industrial Technology and Packaging

In this paper, two types of similarity coefficients are compared: (1) the Jaccard's coefficient and (2) the production volume based coefficient. Each is used to form a cellular manufacturing system whose performance will be used as a measure of effectiveness of the similarity coefficient. The sum of intercellular and intracellular material handling costs is used as a criterion for performance evaluation.

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.