Engineering Commons^™

Ultrasonic Nondestructive Testing Method For Evaluation Of Annular Seals, Nazli Yesiller

Civil and Environmental Engineering

No abstract provided.

Fatigue Behavior Of The Equine Third Metacarpus: Mechanical Property Analysis, V.A. Gibson, S.M. Stover, R.B. Martin, J.C. Gibeling, N. H. Willits, M.B. Gustafson, L.V. Griffin

Biomedical Engineering

This is the first in a series of experiments to study the fatigue properties of equine cannon (third metacarpal) bone specimens from Throughbred racehorses. Monotonic and fatigue tests to failure were performed in four-point bending on diaphyseal specimens in a 37°C saline bath to answer three initial questions. (a) Will a linear variable differential transducer yield the same elastic modulus as strain gauges? (b) Will fatigue results depend on whether the periosteal or endosteal side of the beam is in tension? (c) Are there regional variations in the monotonic and fatigue properties of the cannon bone midshaft? Eighteen left-right pairs …

Fertigation Techniques For Different Irrigation Methods, Charles M. Burt

BioResource and Agricultural Engineering

- The irrigation method influences whether or not chemicals must be injected at a constant rate.
- The irrigation method influences the optimum duration of chemical injection.
- Chemical injection rates may inadvertently vary during an irrigation set for many reasons: improper mixing, system flow rate fluctuations, and system pressure fluctuations
- Drip systems must account for the disposal of filter flush water.

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.

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.

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.

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 …

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 …

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.

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 …

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.

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 …

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 …

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.

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.

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 …

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).

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 …

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.

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

BioResource and Agricultural Engineering

No abstract provided.