Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

PDF

California Polytechnic State University, San Luis Obispo

Series

1998

Discipline
Keyword
Publication

Articles 1 - 30 of 47

Full-Text Articles in Engineering

Fertigation Basics, Charles M. Burt Nov 1998

Fertigation Basics, Charles M. Burt

BioResource and Agricultural Engineering

Fertigation is widely practiced with drip irrigation, yet remains very unsophisticated. Major areas which need improvement are (i) making certain the irrigation system applies water with a high DU (uniformity), (ii) using proper injection pumps and protection hardware, (iii) recognizing that chemicals can interact with each other and with water to form precipitates which will clog emitters, (iv) understanding of nutrient ratios in plants and soil, (v) recognizing that nitrogen fertilization requires attention to the type of nitrogen, and (vi) developing programs for spoon-feeding chemicals. This paper covers the first 4 topics, plus discusses some specific fertilizers.


Model For Trace Metal Exposure In Filter-Feeding Flamingos At Alkaline Rift Valley Lake, Kenya, Yarrow M. Nelson, Ramesh J. Thampy, Gideon K. Motelin, Jackson A. Raini, Cynthia J. Disante, Leonard W. Lion Nov 1998

Model For Trace Metal Exposure In Filter-Feeding Flamingos At Alkaline Rift Valley Lake, Kenya, Yarrow M. Nelson, Ramesh J. Thampy, Gideon K. Motelin, Jackson A. Raini, Cynthia J. Disante, Leonard W. Lion

Civil and Environmental Engineering

Abstract—Toxic trace metals have been implicated as a potential cause of recent flamingo kills at Lake Nakuru, Kenya. Chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn) have accumulated in the lake sediments as a result of unregulated discharges and because this alkaline lake has no natural outlet. Lesser flamingos (Phoeniconaias minor) at Lake Nakuru feed predominantly on the cyanobacterium Spirulina platensis, and because of their filter-feeding mechanism, they are susceptible to exposure to particle-bound metals. Trace metal adsorption isotherms to lake sediments and S. platensis were obtained under simulated lake conditions, and a mathematical model was …


Chemicals For Fertigation, Charles M. Burt Nov 1998

Chemicals For Fertigation, Charles M. Burt

BioResource and Agricultural Engineering

No abstract provided.


Screen Printing Process Design Of Experiments For Fine Line Printing Of Thick Film Ceramic Substrates, Jianbiao Pan, Gregory L. Tonkay, Alejandro Quintero Nov 1998

Screen Printing Process Design Of Experiments For Fine Line Printing Of Thick Film Ceramic Substrates, Jianbiao Pan, Gregory L. Tonkay, Alejandro Quintero

Industrial and Manufacturing Engineering

Screen printing has been the dominant method of thick film deposition because of its low cost. Many experiments in industry have been done and many models of the printing process have been developed since the 1960’s. With a growing need for denser packaging and a drive for higher pin count, screen printing has been refined to yield high resolution prints. However, fine line printing is still considered by industry to be difficult. In order to yield high resolution prints with high first pass yields and manufacturing throughput, the printing process must be controlled stringently.

This paper focuses on investigating the …


A Slip-Line Field For Ploughing During Orthogonal Cutting, Daniel J. Waldorf, Richard E. Devor, Shiv. G. Kapoor Nov 1998

A Slip-Line Field For Ploughing During Orthogonal Cutting, Daniel J. Waldorf, Richard E. Devor, Shiv. G. Kapoor

Industrial and Manufacturing Engineering

Under normal machining conditions, the cutting forces are primarily due to the bulk shearing of the workpiece material in a narrow zone called the shear zone. However, under finishing conditions, when the uncut chip thickness is of the order of the cutting edge radius, a ploughing component of the forces becomes significant as compared to the shear forces. Predicting forces under these conditions requires an estimate of ploughing. A slip-line field is developed to model the ploughing components of the cutting force. The field is based on other slip-line fields developed for a rigid wedge sliding on a half-space and …


Investigation Of A Cyclic Laterally Loaded Model Pile Group, Robb E.S. Moss, Joseph A. Caliendo, Loren R. Anderson Oct 1998

Investigation Of A Cyclic Laterally Loaded Model Pile Group, Robb E.S. Moss, Joseph A. Caliendo, Loren R. Anderson

Civil and Environmental Engineering

In certain regions of the world, designing deep foundations to withstand seismic loading is a reality. Seismic loading of structures and foundations reaches its most critical state as a cyclic lateral force. The response of soils and foundations to repetitive lateral forces is highly complex, relegating most design methods to be based upon overly conservative rules-of-thumb. The primary objective of this research was to analyze the mechanics of seismic loading on pile groups in clay soils. To achieve this a model testing facility was constructed to house a fully instrumented 1 X 5 model pile group that was subjected to …


Fuzzy Logic Control Of A Model Airplane, Jon C. Ervin, Sema E. Alptekin Oct 1998

Fuzzy Logic Control Of A Model Airplane, Jon C. Ervin, Sema E. Alptekin

Industrial and Manufacturing Engineering

Common uses of fuzzy logic control today are found in relatively simple applications in products. These applications only scratch the surface of the potential of fuzzy logic control in complex mechatronic systems. In order to demonstrate the utility of fuzzy logic in complex device control, a fuzzy logic fly-by-wire system has been developed for a model airplane. The model airplane is a complex system of several critical inputs that require rapid processing and action in order to maintain flight stability. In addition, payload and power constraints severely limit the size, weight and processing power of the hardware to be carried …


A Parametric Programming Technique For Efficient Cnc Machining Operations, Manocher Djassemi Oct 1998

A Parametric Programming Technique For Efficient Cnc Machining Operations, Manocher Djassemi

Industrial Technology and Packaging

In this paper the application of parametric programming to CNC machining is discussed. As one of the less frequently utilized features of CNC machines, parametric programming has the potential to increase the efficiency of CNC operations. This feature is particularly beneficial to companies with group technology manufacturing where parts with similar design or operational requirements are processed within a machine cell. Using two case studies, the capabilities of parametric programming for CNC machines are illustrated.


Microstructures And Mechanical Properties Of Two-Phase Alloys Based On Nbcr2, Katherine C. Chen, Paul G . Kotula, Carl M. Cady, Michael E. Mauro, Dan J. Thoma Oct 1998

Microstructures And Mechanical Properties Of Two-Phase Alloys Based On Nbcr2, Katherine C. Chen, Paul G . Kotula, Carl M. Cady, Michael E. Mauro, Dan J. Thoma

Materials Engineering

A two-phase, NbCrTi alloy (bcc + C15 Laves phase) has been developed using several alloy design methodologies. In efforts to understand processing-microstructure-property relationships, different processing routes were employed. The resulting microstructures and mechanical properties are discussed and compared. Plasma arc melted (PAM) samples served to establish baseline, as-cast properties. In addition, a novel processing technique, involving decomposition of a supersaturated and metastable precursor phase during hot isostatic pressing (HIP), was used to produce a refined, equilibrium two-phase microstructure. Quasi-static compression tests as a function of temperature were performed on both alloy types. Different deformation mechanisms were encountered based upon temperature …


Modern Water Control And Management Practices In Irrigation: Impact On Performance, Charles M. Burt, Stuart W. Styles Oct 1998

Modern Water Control And Management Practices In Irrigation: Impact On Performance, Charles M. Burt, Stuart W. Styles

BioResource and Agricultural Engineering

This research addressed the basic questions of what levels of water delivery service are presently provided by irrigation projects having some aspect of modernization; what hardware and software features impact those levels of service; whether modern water control and management practices in irrigation make a positive difference in performance; and what universal lessons can be learned and applied.


Seismic Code Improvements Based On Recorded Motions Of Buildings During Earthquake, Anil K. Chopra, Rakesh K. Goel, Juan Carlos De La Llera Sep 1998

Seismic Code Improvements Based On Recorded Motions Of Buildings During Earthquake, Anil K. Chopra, Rakesh K. Goel, Juan Carlos De La Llera

Civil and Environmental Engineering

Summarized in this paper are the results of two recent investigations utilizing recorded motions of buildings to develop improvements in two aspects of seismic code provisions for buildings: (1) fundamental vibration period formulas, and (2) accidental torsion.


New Cmos Universal Constant-Gm Input Stage, Vladimir I. Prodanov, Michael M. Green Sep 1998

New Cmos Universal Constant-Gm Input Stage, Vladimir I. Prodanov, Michael M. Green

Electrical Engineering

Conceptually new constant-Gm input-stage architecture is presented. It provides near constant net transconductance independent of transistor operating region-strong, moderate or weak inversion. One possible implementation of the proposed architecture is discussed in details. Its operation has been experimentally verified. Results from performed measurements are included.


A Neural Network Pruning Algorithm With Embedded Gradient-Conjugate Training For The Identification Of Large Flexible Space Structures, Xiao-Hua Yu Sep 1998

A Neural Network Pruning Algorithm With Embedded Gradient-Conjugate Training For The Identification Of Large Flexible Space Structures, Xiao-Hua Yu

Electrical Engineering

The choice of network dimension is a fundamental issue in the design of artificial neural networks. A larger neural network is powerful for solving problems while a smaller neural network is always advantageous in real-time environment where speed is crucial. In this paper, a network pruning algorithm with embedded gradient-conjugate training is investigated and applied to the identification of a large flexible space structure. Computer simulation results show that this approach can dramatically reduce the size of neural network while maintaining compatible identification accuracy.


Use Of Polyurethane Material Models For Simulating Leg-Form Impact In Different Explicit Finite Element Codes, Joe Hassan, Peter Schuster, G. Frederick Sep 1998

Use Of Polyurethane Material Models For Simulating Leg-Form Impact In Different Explicit Finite Element Codes, Joe Hassan, Peter Schuster, G. Frederick

Mechanical Engineering

Compressible plastic foams are used throughout the interior and bumper systems of modern automobiles for safety enhancement and damage prevention. Consequently, modeling of foams has become very important for automobile engineers. To date, most work has focused on predicting foam performance up to approximately 80% compression. However, in certain cases, it is important to predict the foam under maximum compression, or 'bottoming-out.' This paper uses one such case-a thin low-density bumper foam impacted by a pedestrian leg-form at 11.1 m/s-to investigate the 'bottoming-out' phenomenon. Multiple material models in three different explicit Finite Element Method (FEM) packages (RADIOSS, FCRASH, and LS-DYNA) …


Navier-Stokes Analysis Of Lift-Enhancing Tabs On Multi-Element Airfoils, Paul G. Carrannanto, Bruce L. Storms, James C. Ross, Russell M. Cummings Sep 1998

Navier-Stokes Analysis Of Lift-Enhancing Tabs On Multi-Element Airfoils, Paul G. Carrannanto, Bruce L. Storms, James C. Ross, Russell M. Cummings

Aerospace Engineering

The flow over multi-element airfoils with flat-plate lift-enhancing tabs was numerically investigated. Tabs ranging in height from 0.25 to 1.25% of the reference airfoil chord were studied near the trailing edge of the main element. The two-dimensional numerical simulation employed an incompressible Navier–Stokes solver using a structured, embedded grid topology. The effects of various tabs were studied at a constant Reynolds number on a two-element airfoil with a slotted flap. Both computed and measured results indicated that a tab in the main-element cove improved the maximum lift and lift-to-drag ratio relative to the baseline airfoil without a tab. Computed streamlines …


Signal Monitoring Apparatus For Wavelength Divison Multiplexed Optical Telecommunication Networks, Dennis J. Derickson, Roger Lee Jungerman Aug 1998

Signal Monitoring Apparatus For Wavelength Divison Multiplexed Optical Telecommunication Networks, Dennis J. Derickson, Roger Lee Jungerman

Electrical Engineering

A detector array spectrometer simultaneously monitors wavelength, power, and signal-to-noise ratio of wavelength division multiplexed (WDM) channels in telecommunication networks. A spectrometer spatially separates signals from the WDM channels according to the channels' wavelengths. The separated signals are incident on an array of split-detectors that conforms to the spatial separation of the signals provided by the spectrometer. While the split-detectors are positioned to receive a signal from each WDM channel, a noise detector is positioned between adjacent split-detectors to measure noise. A common mode output from two halves of each split-detector indicates the power in a WDM channel, while a …


Defects And Site Occupancies In Nb-Cr-Ti C15 Laves Phase Alloys, P. G. Kotula, C. B. Carter, Katherine C. Chen, Dan J. Thoma, F. Chu, T. E. Mitchell Aug 1998

Defects And Site Occupancies In Nb-Cr-Ti C15 Laves Phase Alloys, P. G. Kotula, C. B. Carter, Katherine C. Chen, Dan J. Thoma, F. Chu, T. E. Mitchell

Materials Engineering

No abstract provided.


Selection Of Irrigation Methods For Agriculture: Drip/Micro Irrigation, Charles M. Burt Aug 1998

Selection Of Irrigation Methods For Agriculture: Drip/Micro Irrigation, Charles M. Burt

BioResource and Agricultural Engineering

The ASCE On-Farm Committee has recently completed a draft of a manual (Bliesner et al, 1998) on "Selection of Irrigation Methods for Agriculture." One of the chapters describes drip/micro irrigation methods. Numerous variations of drip/micro designs are discussed, along with advantages and disadvantages. This paper provides an overview of some aspects of that chapter.


Discovering Methodologies For Integrated Product Design, Cirrus Shakeri, David C. Brown, Mohammad N. Noori Jul 1998

Discovering Methodologies For Integrated Product Design, Cirrus Shakeri, David C. Brown, Mohammad N. Noori

Office of the Dean (CENG) Scholarship

The current methodologies for multi-disciplinary product design are based on compromising between different disciplines rather than integrating them. These methodologies do not use a systematic and holistic approach to the problem of multi-disciplinary design and thus are piecemeal rather than comprehensive. This paper presents a new approach to producing design methodologies for integration of the different disciplines in the design process. A multi-agent system has been developed that designs a 2-DOF robot arm by incorporating five proposed strategies for integration between disciplines. Design methodologies are extracted by tracking the system and generalizing the traces that are produced. The results show …


Drip/Micro Irrigation Survey For Delano-Earlimart Irrigation District, Charles M. Burt Jul 1998

Drip/Micro Irrigation Survey For Delano-Earlimart Irrigation District, Charles M. Burt

BioResource and Agricultural Engineering

Delano-Earlimart ID (DEID) has kept informal statistics on the use of drip and micro-irrigation (drip/micro) within its boundaries for several years. These statistics showed that there has been only a slight increase in the acreage of these systems over the past 10 years. Because the rate and extent of conversion to drip/micro may influence the type of future water delivery service needed from DEID, DEID management is interested in knowing more about farmer perceptions regarding these newer irrigation methods.

DEID obtained a grant from USBR Mid-Pacific region to examine perceptions of its farmers regarding future conversions to drip and micro-irrigation. …


Promoting Excellence In Education With An Outstanding Student Instructor Award Program, Jennifer Kadlowec, Justin Shriver, Trevor S. Harding, Charles Choi Jun 1998

Promoting Excellence In Education With An Outstanding Student Instructor Award Program, Jennifer Kadlowec, Justin Shriver, Trevor S. Harding, Charles Choi

Materials Engineering

The ASEE Student Chapter at the University of Michigan in conjunction with the College of Engineering has developed and organized an annual Outstanding Student Instructor Award in recognition of excellence in engineering education. The award not only acknowledges the outstanding contributions of the individuals selected for the award, but also coincides with the ASEE’s goals of promoting excellence in engineering education and attracting new members. The paper outlines the planning procedures developed since the inception of the award in 1994 and provides suggestions and insights for other ASEE Student Chapters to create and organize such an award.


Optimization Of Network Signal Timing, Xiao-Hua Yu, Allen R. Stubberud Jun 1998

Optimization Of Network Signal Timing, Xiao-Hua Yu, Allen R. Stubberud

Electrical Engineering

A typical urban traffic network is a complicated large-scale stochastic system which consists of many interconnected signalized traffic intersections. This paper develops a decentralized real-time adaptive control strategy for the traffic networks based on Markov decision theory. Computer simulation results of this new approach on a five intersection traffic network indicate significant improvement over the traditional fully actuated control algorithm.


Techniques For Modeling Hazardous Air Pollutant Emissions From Landfills, Robert J. Lang, Samuel A. Vigil, Henryk Melcer Jun 1998

Techniques For Modeling Hazardous Air Pollutant Emissions From Landfills, Robert J. Lang, Samuel A. Vigil, Henryk Melcer

Civil and Environmental Engineering

The Environmental Protection Agency’s Landfill Air Estimation Model (LAEEM), combined with either the AP-42 or CAA landfill emission factors, provide a basis to predict air emissions, including hazardous air pollutants (HAPs), from municipal solid waste landfills. This paper presents alternative approaches for estimating HAP emissions from landfills. These approaches include analytical solutions and estimation techniques that account for convection, diffusion, and biodegradation of HAPs. Results from the modeling of a prototypical landfill are used as the basis for discussion with respect to LAEEM results.


Preliminary Development Of A Certification Protocol For Conventional Fireplaces, Paul L. Reitz, Harold M. Cota Jun 1998

Preliminary Development Of A Certification Protocol For Conventional Fireplaces, Paul L. Reitz, Harold M. Cota

Civil and Environmental Engineering

In order to attain and maintain federal and state air quality standards for particulate matter, some local agencies in California have adopted rules and regulations to control emissions from wood burning devices. Some of these rules restricted the use or installation of new masonry fireplaces. The purpose of this study was to begin development of a test protocol that would provide for consistent measurement of particulate emissions from conventional fireplaces and could be useful for compliance determinations or possible certification of a fireplace design or model. A modified California Air Resources Board Stationary Source Test Method 5 was used to …


Improving Water Properties To Increase Infiltration Characteristics, Richard W. O. Soppe, Stuart W. Styles Jun 1998

Improving Water Properties To Increase Infiltration Characteristics, Richard W. O. Soppe, Stuart W. Styles

BioResource and Agricultural Engineering

Water properties, such as the viscosity and surface tension, can be affected by temperature and surfactants to Increase infiltration rates into soils. Specifically, they will change the hydraulic conductivity of the soil. A simple soap solution and the new material PAM (inexpensive polymer chemical) were evaluated as surfactants. Laboratory experiments and field tests on a site in Davis, California were done to quantify the effects of changing the water properties. Additional effects, like the improved soil structure during infiltration and less soil particles in tailwater (reduced erosion due to runoff) were observed and are described in this paper. The conclusions …


Redesigning Engineering Education, William W. Durgin, Edward A. Parrish Jun 1998

Redesigning Engineering Education, William W. Durgin, Edward A. Parrish

Office of the Provost Scholarship

In developing the PLAN, WPI sought to address concerns inherent to its then traditional curriculum that was rigid, unresponsive to differences among students, and was compartmentalized by independent departments so that intellectual growth was fragmented.

The PLAN was an entirely new and different educational program responsive to the needs of students and society while nurturing sensitivity to the ideas and values of our society. It included fundamental departures from the traditional elements of technical education including:
A. The achievement of competence rather than the accumulation of credits.
B. Individual freedom and responsibility in planning the program of study.
C. A …


Experimental Analysis Of Desiccation Crack Propagation In Clay Liners, Carol J. Miller, Hong Mi, Nazli Yesiller Jun 1998

Experimental Analysis Of Desiccation Crack Propagation In Clay Liners, Carol J. Miller, Hong Mi, Nazli Yesiller

Civil and Environmental Engineering

A laboratory investigation on a scaled model of a landfill liner was conducted to provide data regarding the occurrence and extent of desiccation cracking of prototype liners. The crack intensity factor, CIF, was introduced as a descriptor of the extent of surficial cracking. CIF is defined as the ratio of the surface crack area A, to the total surface area of the clay liner, At. A computer aided image analysis program was used to determine CII’ values from scanned photographs of the desiccation process. The variation of the CII’ was related to duration of drying and measured soil moisture suctions. …


Numerical Investigation Of An Airfoil With A Gurney Flap, Cory S. Jang, James C. Ross, Russell M. Cummings Jun 1998

Numerical Investigation Of An Airfoil With A Gurney Flap, Cory S. Jang, James C. Ross, Russell M. Cummings

Aerospace Engineering

A two-dimensional numerical investigation was performed to determine the effect of a Gurney flap on a NACA 4412 airfoil. A Gurney flap is a flat plate on the order of 1–3% of the airfoil chord in length, oriented perpendicular to the chord line and located on the airfoil windward side at the trailing edge. The flowfield around the airfoil was numerically predicted using INS2D, an incompressible Navier–Stokes solver, and the one-equation turbulence model of Baldwin and Barth. Gurney flap sizes of 0.5%, 1.0%, 1.25%, 1.5%, 2.0%, and 3.0% of the airfoil chord were studied. Computational results were compared with available …


Electroluminescent Device Having Electroluminescent Compound And Liquid Crystalline Compound, Rifat A.M. Hikmet, David Braun, Aemilianus G.J. Staring, Hermanmus F.M. Schoo, Johan Lub May 1998

Electroluminescent Device Having Electroluminescent Compound And Liquid Crystalline Compound, Rifat A.M. Hikmet, David Braun, Aemilianus G.J. Staring, Hermanmus F.M. Schoo, Johan Lub

Electrical Engineering

A description is given of an electroluminescent device (1) having an LED structure, which is composed of an active layer (7) of oriented liquid-crystalline and electroluminescent compounds and a transparent positive electrode layer (5) which is preferably made from an electroconductive polymer. By previously rubbing the electrode layer (5) in one direction with a velvet cloth, an orientation is induced in the molecules in the active layer (7), the orientation being frozen by cooling or polymerization. The electroluminescent device (1) emits polarized light whose direction of polarization is parallel to the direction of rubbing.


The Effects Of Beryllium Additions On The Oxidation Of Nickel Aluminide And Titanium Aluminide Based Intermetallics, R. H. Hanrahan Jr., Katherine C. Chen, M. P. Brady May 1998

The Effects Of Beryllium Additions On The Oxidation Of Nickel Aluminide And Titanium Aluminide Based Intermetallics, R. H. Hanrahan Jr., Katherine C. Chen, M. P. Brady

Materials Engineering

The effects of Be additions on the oxidation behavior of β-NiAl in moist air at 1000°C and borderline alumina-forming y (TiAI) + Laves Ti-Al-Cr based alloys at 800°C and 1000°C in dry and moist air were investigated. The addition of Be to β-NiAl suppressed the formation of transient alumina, and resulted in the formation of a protective BeAl2O4 spinel phase. In dry air, the addition of Be to the Ti-AI-Cr alloys also resulted in the formation of a protective BeAl2O4 spinel phase. In moist air, only Ti-AlCr- Be alloys with a high Cr content …