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

Engineering Commons™

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

Series

Discipline
Institution
Keyword
Publication Year
Publication
File Type

Articles 68491 - 68520 of 75070

Full-Text Articles in Engineering

Comparison Of Bulk Density Beneath A Belt Track And Tire, Leonard L. Bashford, A. J. Jones, L. N. Mielke Jun 1988

Comparison Of Bulk Density Beneath A Belt Track And Tire, Leonard L. Bashford, A. J. Jones, L. N. Mielke

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Wheel traffic is considered a major cause of soil compaction in production agriculture. Soil compaction depends on initial conditions, load, contact area and tire type and shape at the soil surface. The use of tractors equipped with tracks instead of tires has the potential of reducing soil compaction because of reduced surface contact pressure and difference in load distribution over a relatively long-narrow track. The introduction of a new agricultural tractor equipped with a rubber belt track permits a crawler tractor to compete with a large four-wheel drive tractor in both speed and mobility.
Soil bulk density was measured as …


Measurement And Simulation Of One-Dimensional Transient Three Phase Flow For Monotonic Liquid Drainage, R. J. Lenhard, J. Dane, J. C. Parker, Jagath J. Kaluarachchi Jun 1988

Measurement And Simulation Of One-Dimensional Transient Three Phase Flow For Monotonic Liquid Drainage, R. J. Lenhard, J. Dane, J. C. Parker, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

Simultaneous movement of oil, water, and air in a sandy porous medium was investigated experimentally under transient flow conditions and results were compared to numerical simulations employing a finite element multiphase flow code. The liquid hydrocarbon was Soltrol 170, a low-density branched alkane mixture. Liquid saturations were measured using a collinear dual-energy gamma radiation apparatus and liquid pressures were measured using hydrophilic (untreated) and hydrophobic (treated) ceramic tensiometers connected to pressure transducers. The experimental regime was selected to impose monotonically draining water and total liquid saturation paths to avoid hysteretic effects. Measured saturations and pressures are compared to values obtained …


A 100-Khz - 22 Ghz Instrumentation Photoreceiver, Dennis J. Derickson, C. M. Miller, R. L. Van Tuyl May 1988

A 100-Khz - 22 Ghz Instrumentation Photoreceiver, Dennis J. Derickson, C. M. Miller, R. L. Van Tuyl

Electrical Engineering

A photoreceiver consisting of a high-speed p-i-n photodetector and a 100-kHz to 22-GHz distributed amplifier is described. Photoreceiver calibration is accomplished by optical heterodyne techniques. The photoreceiver is used with a microwave spectrum analyzer to produce a fully amplitude-calibrated 22-GHz-bandwidth lightwave signal analyzer system for displaying intensity-modulated light with -65-dB (optical) sensitivity at 1300-nm and 1550-nm wavelengths.


Common Characteristics Of Paired Volcanoes In Northern Central America, S. P. Halsort, William I. Rose May 1988

Common Characteristics Of Paired Volcanoes In Northern Central America, S. P. Halsort, William I. Rose

Department of Geological and Mining Engineering and Sciences Publications

Four pairs of active volcanoes along the northern Central American volcanic front have erupted basalt-andesite magmas that show consistent intrapair behavioral and compositional differences. These differences are found in records of volcanic activity and complete major and minor element data on over 200 samples. From northwest to southeast along the volcanic front the four volcano pairs are Cerro Quemado-Santa María, Tolimán-Atitlán, Acatenango-Fuego, and Santa Ana-Izalco. The volcano pair relations help explain compositional differences, apart from those reflecting variation in crustal thickness of about 15 km along the volcanic front, providing insight into across-arc variations and closely spaced subvolcanic plumbing systems. …


Direct Rate Measurements Of Eruption Plumes At Augustine Volcano: A Problem Of Scaling And Uncontrolled Variables, William I. Rose, Grant Heiken, Kenneth Wohletz, Dean Eppler, Sumner Barr, Theresa Miller, Raymond L. Chuan, R. B. Symonds May 1988

Direct Rate Measurements Of Eruption Plumes At Augustine Volcano: A Problem Of Scaling And Uncontrolled Variables, William I. Rose, Grant Heiken, Kenneth Wohletz, Dean Eppler, Sumner Barr, Theresa Miller, Raymond L. Chuan, R. B. Symonds

Department of Geological and Mining Engineering and Sciences Publications

The March–April 1986 eruption of Augustine Volcano, Alaska, provided an opportunity to directly measure the flux of gas, aerosol, and ash particles during explosive eruption. Most previous direct measurements of volcanic emission rates are on plumes from fuming volcanoes or on very small eruption clouds. Direct measurements during explosive activity are needed to understand the scale relationships between passive degassing or small eruption plumes and highly explosive events. Conditions on April 3, 1986 were ideal: high winds, clear visibility, moderate activity. Three measurements were made: 1) an airborne correlation spectrometer (Cospec) provided mass flux rates of SO2; 2) …


Digital Optical Iterative Pattern Recognizer, Samuel Peter Kozaitis, C. S. Kischuk May 1988

Digital Optical Iterative Pattern Recognizer, Samuel Peter Kozaitis, C. S. Kischuk

Electrical Engineering and Computer Science Faculty Publications

An optical pattern recognizer which classifies an input sequence into one of two classes is described. The language of regular expressions is used to identify a set of input sequences to be recognized. The system is realized without memory elements by using an optical iterative array it with the method of symbolic substitution. The hardware must be able to implement arbitrary and multiple substitution rules for the general design of a pattern recognizer. © 1988 SPIE


Operations-Based Training Strategy For Longwall Mining, R. Larry Grayson, Michael J. Klishis, Ronald C. Althouse, George M. Lies May 1988

Operations-Based Training Strategy For Longwall Mining, R. Larry Grayson, Michael J. Klishis, Ronald C. Althouse, George M. Lies

Mining Engineering Faculty Research & Creative Works

A system that can be used to pinpoint the specific training needs of operations and assist in the design and upgrading of focused training approaches can benefit longwall mining. It can be directed at systematically correcting performance discrepancies at an individual, crew, or mine level, and also to challenge workers and management toward attaining improved performances. Such an approach involves a combination of features, such as diligence in monitoring and evaluating performances, thorough coordination in implementing changes, and effective use of operational data.

The Bureau of Mines, through contract with the Mining Extension Service of West Virginia University, has developed …


Spectral Behavior And Pulse Train Instabilities Of A Synchronously Pumped Mode-Locked Dye Laser, Duncan Leo Macfarlane, Lee W. Casperson, Anthony A. Tovar May 1988

Spectral Behavior And Pulse Train Instabilities Of A Synchronously Pumped Mode-Locked Dye Laser, Duncan Leo Macfarlane, Lee W. Casperson, Anthony A. Tovar

Electrical and Computer Engineering Faculty Publications and Presentations

The pulse-train envelope of a synchronously pumped mode-locked dye laser has been experimentally studied as a function of cavity length detuning. When a bandwidth-limiting birefringent tuning filter is included and the cavity is adjusted to the length that yields optimally short (˜2-psec) pulse, there is a slow (≤800 kHz), erratic amplitude modulation that provides a 20% variation in pulse energies. As the cavity length is detuned on the order of one part in 10⁴, the modulation vanishes, but the individual pulse lengths increade dramtically. Further detuning results in a clean periodic envelope with a 20% modulation depth and a˜5-μsec period. …


Evaluation Of Extruded Thermoplastics As Lane Delineation, Kenneth R. Agent, Jerry G. Pigman May 1988

Evaluation Of Extruded Thermoplastics As Lane Delineation, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

This study involved an evaluation of large-scale installations of both hydrocarbon and alkyd extruded thermoplastics as lane delineation on sections of interstate highways having open-graded surfaces. The objective of the study was to evaluate the performance of thermoplastics as lane delineation and to compare the performance of hydrocarbon versus alkyd formulations.

Data were collected on a periodic basis over an 18-month period. Data collection consisted of daytime observations of the appearance and durability of the thermoplastic material along with reflectivity measurements using a portable retroreflectometer.

The evaluation revealed that both the hydrocarbon and alkyd extruded thermoplastic material maintained their appearance, …


Using A Partial Order And A Metric To Analyze A Recursive Trace Set Equation, Jan Tijmen Udding, Tom Verhoeff May 1988

Using A Partial Order And A Metric To Analyze A Recursive Trace Set Equation, Jan Tijmen Udding, Tom Verhoeff

All Computer Science and Engineering Research

In Trace Theory the notion of a process is defined in terms of a set of finite-length traces over an alphabet. These processes are used as the semantics for a program notation. The program text for a recursive component naturally gives rise to an equation over trace sets. This paper takes two approaches at the analysis of that equation. The first approach is based on a partial order and it concentrates on the projection operator for processes. This yields a condition under which the greatest solution of that equation can be approximated by iteration. The second approach introduces a metric …


Spontaneous Coherent Pulsations In Standing-Wave Laser Oscillators, Lee W. Casperson May 1988

Spontaneous Coherent Pulsations In Standing-Wave Laser Oscillators, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Spontaneous pulsation phenomena in xenon lasers are now well known, and related effects have been observed with other laser types. Most theoretical analyses of such pulsations are formulated for unidirectional ring lasers, whereas most experiments involve standing-wave resonator geometries. Described here are rigorous semiclassical models governing the spontaneous pulsation instability in standing-wave laser oscillators. The standing-wave results are more complex and closer to experimental observations than the ring results for operation in the Lambdip region near line center.


Guide To Revenue Calculations: Local Option Highway User Tax 1988, Herpicc May 1988

Guide To Revenue Calculations: Local Option Highway User Tax 1988, Herpicc

Indiana Local Technical Assistance Program (LTAP) Publications

This guide is provided to explain the output generated by the computer programs and to suggest ways in which the results can be adapted to specific LOHUT proposals before a County Council. The 1988 LOHUT revenue projections are of special interest because of House Enrolled Act Number 1295. This act (IC 8-11-5) granted each county authority to bond for county roads or bridges, but only if a county has first adopted a LOHUT -- the excise surtax (IC 6-3.5-4) and wheel tax (IC 6-3.5-5).

HERPICC neither endorses nor opposes passage of a LOHUT. The revenue projections it provides are intended …


General Analysis And Optimization Of The Four-Detector Photopolarimeter, R. M.A. Azzam, I. M. Elminyawi, A. M. El-Saba May 1988

General Analysis And Optimization Of The Four-Detector Photopolarimeter, R. M.A. Azzam, I. M. Elminyawi, A. M. El-Saba

Electrical Engineering Faculty Publications

The four-detector photopolarimeter (FDP) is analyzed for an arbitrary spatial configuration and any reflection characteristics (ri, ψi, Δi) of the first three detectors. The instrument matrix A, which relates the output signal vector I to the input Stokes vector S by I = AS, and its determinant are derived explicitly. The essential condition that A be nonsingular (det A ≠ 0) is satisfied in general with uncoated absorbing detector surfaces, assuming that the plane of incidence (POI) is rotated between successive reflections by other than 90°. Therefore no special coatings on …


On Purely Exponential Logic Queries, Kazem Taghva, Tian-Zheng Wu May 1988

On Purely Exponential Logic Queries, Kazem Taghva, Tian-Zheng Wu

Electrical & Computer Engineering Faculty Research

The recursive nature of logic programs has long been the subject of optimization techniques [2, 8]. Recently, the database community has taken interest in extending the expressive power of relational algebra by augmenting it with function-free Horn style logic queries. This extension has led to various optimization techniques [2, 6, 8]. It seems, almost invariably, these techniques are most efficient in the processing of linear recursive queries. Moreover, as the equivalence of nonlinear rules to linear rules in general is undecidable [3, 9], the best one can hope is to rewrite some nonlinear rules as linear rules. For this reason, …


Rbs Technology: Task 3 Report, Florida Solar Energy Center, Philip W. Fairey Apr 1988

Rbs Technology: Task 3 Report, Florida Solar Energy Center, Philip W. Fairey

FSEC Energy Research Center®

The purpose of this report is to discuss the current state of attic radiant barrier system (RBS) technology. Concepts, research issues and experimental test results are presented and discussed.


Modal Interference Techniques For Strain Detection In Few-Mode Optical Fibers, Bradley D. Duncan Apr 1988

Modal Interference Techniques For Strain Detection In Few-Mode Optical Fibers, Bradley D. Duncan

Electro-Optics and Photonics Faculty Publications

Interference between the modes of an optical fiber results in specific intensity patterns which can be modulated as a function of disturbances in the optical fiber system. These modulation effects are a direct result of the difference in propagation constants of the constituent modes. In this presentation it is shown how the modulated intensity patterns created by the interference of specific mode groups in few-mode optical fibers (V < 5.0) can be used to detect strain. A detailed discussion of the modal phenomena responsible for the observed strain induced pattern modulation is given and it is shown that strain detection sensitivities on the order of 10-9 can be expected. Data taken during the evaluation of an actual experimental strain detection system based on the developed theory is also presented.


Test 1607: White 160 Diesel And White Workhorse 170 Diesel 18-Speed, Nebraska Tractor Test Lab Apr 1988

Test 1607: White 160 Diesel And White Workhorse 170 Diesel 18-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …


Test 1608: Field Boss 185 Diesel, White 185 Diesel And White Workhorse 195 Diesel 18-Speeds, Nebraska Tractor Test Lab Apr 1988

Test 1608: Field Boss 185 Diesel, White 185 Diesel And White Workhorse 195 Diesel 18-Speeds, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …


Acuta Enews May & April 1988, Vol. 17, No. 4 & 5 Apr 1988

Acuta Enews May & April 1988, Vol. 17, No. 4 & 5

ACUTA Newsletters

In This Issue

President's Message

Party Line

The 10 Commandments of Telecommunications

Squeezing Phone Lines For All They're Worth

Call for Nominations

From Region 2

Keeping the Telephone Alive

911- Miami University


Evaluation Of Lime Stabilized Road Bed, Bobby W. Meade, David L. Allen Apr 1988

Evaluation Of Lime Stabilized Road Bed, Bobby W. Meade, David L. Allen

Kentucky Transportation Center Research Report

In October 1986, the Transportation Research Program of the University of Kentucky published a report evaluating the addition of hydrated lime to the subgrade soils of Section 19 of the Ashland-Alexandria (AA.) highway (1). That study involved laboratory testing only and concluded that the engineering properties of these subgrade soils were significantly improved with the addition of 6 percent (by weight) hydrated lime. It was decided to add hydrated lime to the subgrade soils on Section 19.

Because that procedure had not previously been used in Kentucky, a study was approved to monitor construction procedures and the performance of an …


Parallel Simulated Annealing, Roger D. Chamberlain, Mark N. Edelman, Mark A. Franklin, Ellen E. Witte Apr 1988

Parallel Simulated Annealing, Roger D. Chamberlain, Mark N. Edelman, Mark A. Franklin, Ellen E. Witte

All Computer Science and Engineering Research

Since the paper by Kirkpatrick, Gelatt and Vecchi in 1983, the use of Simulated Annealing (SA) in solving combinatoric optimization problems has increased substantially. The SA algorithm has been applied to difficult problems in the difficult problems in the digital design automation such as cell placement and wire routing. While these studies have yielded good or near optimum solutions, they have required very long computer execution times (hours and days). These long times, coupled with the recent availability of the number of commercial parallel processors, has prompted the search for parallel implementations of the SA algorithm. The goal ahs been …


Performance Models For Noahnet, Gurudatta M. Parulkar, Adarshpal S. Sethi, David J. Farber Apr 1988

Performance Models For Noahnet, Gurudatta M. Parulkar, Adarshpal S. Sethi, David J. Farber

All Computer Science and Engineering Research

Noahnet is an experimental flood local area network with features such as high reliability and high performance. Noahnet uses a randomly connected graph topology with four to five interconnections per node and a flooding protocol to route messages. In Noahnet flooding, the routing of a message from a source to the destination node is a two step process: flooding-growth and flooding-contraction. During the growth of flooding, the message propagates to every node which is not occupied with a message and is reachable from the source node. During the contraction of flooding, the nodes that became occupied during the growth of …


Structural Characterization Of A High-Temperature, Ionic Conducting Ceramic Using Perturbed Angular Correlation Spectroscopy, Gary L. Catchen, Michael Blaszkiewicz, Khalid Jamil, Dinesh K. Agrawal, Wayne Huebner, Herbert A. Mckinstry, Lorenz H. Menke Jr. Apr 1988

Structural Characterization Of A High-Temperature, Ionic Conducting Ceramic Using Perturbed Angular Correlation Spectroscopy, Gary L. Catchen, Michael Blaszkiewicz, Khalid Jamil, Dinesh K. Agrawal, Wayne Huebner, Herbert A. Mckinstry, Lorenz H. Menke Jr.

Materials Science and Engineering Faculty Research & Creative Works

Perturbed angular correlation (PAC) spectroscopy has been used to characterize several structural aspects of a high-temperature, ionic conducting ceramic, CaZr3.95Hf0.05P6O24. Hafnium was introduced into the material to provide the PAC probe nuclei, 181Hf/181Ta, which were located primarily at Zr sites. PAC measurements were made over a range of temperatures from 77 to 1180 K, and they have been analyzed and interpreted using several simple models. The distorted octahedral crystal field at the Zr site produced a (low-frequency) static electric quadrupole interaction which can be accurately described by the point-charge model. But, the temperature dependence of the associated electric field gradient …


A Comment On ‘Failure Modes Of Hybrid Composites …’, Serge Abrate Mar 1988

A Comment On ‘Failure Modes Of Hybrid Composites …’, Serge Abrate

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper comments on an earlier paper on the failure modes of hybrid composites by Pitkethly and Bader, which appeared in the Carbon Fiber Conference issue. © 1988 IOP Publishing Ltd.


Stability Of Steady Cross-Waves: Theory And Experiment, Seth Lichter, Andrew J. Bernoff Mar 1988

Stability Of Steady Cross-Waves: Theory And Experiment, Seth Lichter, Andrew J. Bernoff

All HMC Faculty Publications and Research

A bifurcation analysis is performed in the neighborhood of neutral stability for cross waves as a function of forcing, detuning, and viscous damping. A transition is seen from a subcritical to a supercritical bifurcation at a critical value of the detuning. The predicted hysteretic behavior is observed experimentally. A similarity scaling in the inviscid limit is also predicted. The experimentally observed bifurcation curves agree with this scaling.


Acuta Enews March 1988, Vol. 17, No. 3 Mar 1988

Acuta Enews March 1988, Vol. 17, No. 3

ACUTA Newsletters

In This Issue

President's Message

Party Line

17th Annual Summer Conference

Potpourri

From the Board

Plan Now For San Diego

The University of British Columbia

The Other Side of T-1


Excessive Beam Deflections On The Ky-52 Bridge Over Dix River (Boyle-Garrard County Line), Theodore Hopwood Ii, Vishwas G. Oka, David Q. Hunsucker, James H. Havens Mar 1988

Excessive Beam Deflections On The Ky-52 Bridge Over Dix River (Boyle-Garrard County Line), Theodore Hopwood Ii, Vishwas G. Oka, David Q. Hunsucker, James H. Havens

Kentucky Transportation Center Research Report

Upon rehabilitation, beams and deck of the Ky 52 bridge over Dix River were observed to have excessive deflections. An investigation of the problem included field inspections, structural analyses, and interviews with relevant KYDOH and other personnel.

Field measurements were made of the beam deflections. Those were compared to construction field measurements and dead-load calculations.

The beam deflection problem is attributed to 1) a failure to provide for sufficient camber in the beams to accommodate for construction dead loads, and 2) pre-existing sags in the beams when placed prior to casting the deck. Part of the deck deflection problem can …


Allocation Of Highway Costs And Revenues, Jerry G. Pigman, John A. Deacon Mar 1988

Allocation Of Highway Costs And Revenues, Jerry G. Pigman, John A. Deacon

Kentucky Transportation Center Research Report

A continuing task related to highway financing is determination of the appropriate level of taxation for each class of highway user. Cost allocation in various forms has traditionally been the tool used to achieve an equitable assignment of user responsibility. Following is a summary of results from such a cost-allocation study undertaken by the University of Kentucky's Transportation Research Program. The objective of this study is to determine highway cost responsibility of various user classes and to assess revenues relative to costs under existing levels of taxation and under various alternatives considered in the 1988 legislative session.


Evaluation Of Procedures For Testing Aggregates, David Q. Hunsucker Mar 1988

Evaluation Of Procedures For Testing Aggregates, David Q. Hunsucker

Kentucky Transportation Center Research Report

This report summarizes findings of a research study conducted to evaluate aggregate testing procedures as related to aggregate soundness and durability. The objectives of the study were to determine a suitable replacement or modification of Kentucky's existing Sodium Sulfate Soundness Test for aggregates which would more accurately reflect in-service performance of concrete pavements and bridges, to correlate freezing and thawing durability data and other test data with sodium sulfate soundness data, and to develop a rational implementation criterion for use of new or modified testing procedures.

There were no observable correlations between the various test methods evaluated and the Sodium …


Hierarchical Discrete-Event Simulation On Hypercube Architecture, Roger D. Chamberlain, Mark A. Franklin Mar 1988

Hierarchical Discrete-Event Simulation On Hypercube Architecture, Roger D. Chamberlain, Mark A. Franklin

All Computer Science and Engineering Research

This paper presents model of hierarchical discrete-event simulation algorithm running on a hypercube architecture. We assume a static allocation of system components to processors in the hypercube. We also assume a global clock algorithm, with an event-based time increment. Following development of the performance model, we describe an application of the model in the area of digital systems simulation. Hierarchical levels included are gate level (NAND, NOR, and NOT gates) and MSI level (multiplexors, shift registers, etc.). Example values (gathered from simulations running on standard von Neumann architectures) are provided at the model inputs to show the effect of different …