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Articles 187441 - 187470 of 193442

Full-Text Articles in Engineering

Discussion On Skid Resistance Of Pavement Surfaces, Rolands L. Rizenbergs Sep 1968

Discussion On Skid Resistance Of Pavement Surfaces, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

The concern for adequate skid resistance or friction of pavement surfaces is confined to wet weather conditions. Dry pavements are highly skid resistant unless the surface contains loose material, such as gravel, sand, etc., which could provide rolling action by the particles under the tires. Surface contaminates, such as oil, soft tars and asphalt, etc., could also provide lubrication to the surface and create a slippery condition. Normally, however, water is the lubricating agent reducing pavement friction and in some cases creating very hazardous driving conditions. Another situation of concern is drainage, or lack of proper drainage, of the pavement. …


I-75 Kenton County Slide, Herbert F. Southgate Sep 1968

I-75 Kenton County Slide, Herbert F. Southgate

Kentucky Transportation Center Research Report

No abstract provided.


10th Annual Rocky Mountain Spectroscopy Conference Aug 1968

10th Annual Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 10th annual meeting of the Rocky Mountain Spectroscopy Conference, sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 19-20, 1968.


An Analysis And Comparison Of Linear Phase Bandpass Filters, Darrell L. Ash Aug 1968

An Analysis And Comparison Of Linear Phase Bandpass Filters, Darrell L. Ash

Theses and Dissertations

The ideal bandpass filter is defined as one which uniformly attenuates and delays all frequency components within the passband and effects zero transmission of all components outside the passband. For reasons which will be subsequently discussed, it is impossible to realize a stable lumped-element filter having this ideal characteristic. This has made it necessary to find ways to physically approximate such a characteristic. Some of the more widely used methods will be compared and analyzed in this paper.


Determination Of Traffic Parameters For The Prediction, Projection, And Computation Of Ewl’S, John A. Deacon, Robert L. Lynch Aug 1968

Determination Of Traffic Parameters For The Prediction, Projection, And Computation Of Ewl’S, John A. Deacon, Robert L. Lynch

Kentucky Transportation Center Research Report

One of the first published methods for the structural design of highway pavements was called the Massachusetts Rule and was presented in the eighth annual report of the Massachusetts Highway Commission in 1901 (1). The essence of this procedure was a rather intuitive assumption concerning the distribution of vertical pressures beneath a loaded area. For design purposes, this required the selection of a design load which, since failure was assumed to be catastrophic and not cumulative, could be taken as the largest load that could reasonably be anticipated during the design life of the pavement. The prediction of such a …


Equivalent Axleloads For Pavement Design, John A. Deacon, Robert C. Deen Aug 1968

Equivalent Axleloads For Pavement Design, John A. Deacon, Robert C. Deen

Kentucky Transportation Center Research Report

Proper structural design of highway pavements requires an evaluation of the destructive effects of the anticipated vehicular loading. The concept of load equivalency provides a means for expressing these destructive effects in terms of a single measure, the equivalent axleloads (EAL's). The design EAL's represents the equivalent number of applications of a standard or base axleload anticipated during the design life.


Florida Skid Correlation Study Of 1967 – Skid Testing With Automobiles, Rolands L. Rizenbergs Aug 1968

Florida Skid Correlation Study Of 1967 – Skid Testing With Automobiles, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

The inclusion of automobiles in the Florida skid correlation study was promoted by the recognition of the following needs: 1) to compare stopping-distance measurements obtained with different instrumentation, 2) to suggest a standard method of stopping-distance testing, 3) to relate skid-resistance measurements of trailer-type testers with stopping distances of automobiles, and 4) to explore other skid-resistance measurements techniques using an automobile.

The vehicles were all full-size automobiles. Each vehicle was instrumented to measure a distance from a predetermined pressure in the brake hydraulic system to where the vehicle came to rest. Stopping distance in most of the automobiles was read …


Kentucky Rock Asphalt Hot-Mix Surfaces, Robert L. Florence Aug 1968

Kentucky Rock Asphalt Hot-Mix Surfaces, Robert L. Florence

Kentucky Transportation Center Research Report

When this study was initiated in 1962, the objectives were disposed toward the development of Kentucky Rock Asphalt for use as a traffic-bound base and surface on rural roads near its source and toward redevelopment of the material for use as hot-mixed, hot-laid, skid-resistant surface course for higher echelon roads. Between July 1962 and August 1965, eight experimental, lean rock-asphalt bases were constructed and evaluated (1, 2, 3).

During the fall of 1965 a hot-mixed, enriched, rock-asphalt surfacing material was successfully produced through a conventional hot-mix plant and laid with a paver on a 8.4-mile section of Nolin Dam Road …


Experimental Applications Of Protective Coatings To Shales Exposed In Highway Cuts, James H. Havens Aug 1968

Experimental Applications Of Protective Coatings To Shales Exposed In Highway Cuts, James H. Havens

Kentucky Transportation Center Research Report

Many shales exposed in roadway cut-sections are susceptible to weathering, slaking, and erosion; fallout and taluses clog drainage; benches overflow; and occasionally landslides or rockslides develop. Presently, in design, certain types of shales and even named formations are afforded wider benches than others; soil mantles at the tops of cuts are being stripped back farther; and, of course, sound ledge-rock offers the preferred type of bench-cap. Pre-splitting methods of blasting have greatly enhanced the appearance of cuts and have minimized the shattering of cut faces. The resulting surfaces frequently are quite smooth when first exposed and remain so if the …


Performance Of A Reinforced Concrete Pipe Culvert Under Rock Embankment, Robert C. Deen Aug 1968

Performance Of A Reinforced Concrete Pipe Culvert Under Rock Embankment, Robert C. Deen

Kentucky Transportation Center Research Report

A 48-inch diameter reinforced concrete pipe installation has been observed in order to evaluate the performance of both types of bedding conditions as currently used by the Kentucky Department of Highways. A portion of the pipe was laid using Kentucky's Standard B Bedding. The remainder of the pipe culvert was laid using the B1 Bedding (imperfect trench); the design height of the fill (36 feet) was sufficient to require the imperfect trench construction. The embankment was primarily of a rock fill material, with the largest particle size limited to a maximum of 3 feet. The portion of the pipe …


Durability Of Culvert Pipe, James H. Havens Aug 1968

Durability Of Culvert Pipe, James H. Havens

Kentucky Transportation Center Research Report

Almost twenty years ago the Department began to develop durability data on types of culvert materials. In the interim, various stopgap as well as very judicious policies have issued. The present criterion or design practice applicable to Federal Aid projects was affirmed by the Bureau of Public Roads, May 24, 1965. Extensive field surveys have been conducted; various design innovations have been employed; and a "hot" test site has, in a demonstrative way, provided critical life-expectancy records. All past history had been documented previously; however, a brief retrospective summary will provide some continuity between forethought and certain issues now maturing.


An Experimental Investigation Of Proportional Braking, Rudolf Limpert Aug 1968

An Experimental Investigation Of Proportional Braking, Rudolf Limpert

Theses and Dissertations

In recent years automobile safety has become more and more important.The braking device contributes largely to the problem of safe driving.


Design And Operation Of Equipment For Impact Test Of A Hydraulic Cushion, Harshadbhai R. Patel Aug 1968

Design And Operation Of Equipment For Impact Test Of A Hydraulic Cushion, Harshadbhai R. Patel

Theses and Dissertations

In recent years, experiments have been carried out to evaluate the performance of water-filled cushion cells used to attenuate energy of automobile collisions. The water-filled cushion cell is a vinyl plastic cylinder of 6 inches nominal outside diameter, 1/4 inch wall thickness, 40 inches length, closed at the bottom by a cast-in-place vinyl plug and partially closed by a bolted-in vinyl diaphragm at the upper end. These cells are designed to be installed in the path of a crashing automobile to absorb and dissipate the kinetic energy of impact. Properly designed cushions could be used as one means of saving …


Development Of A Generalized Structural Dynamics Computer Program, Val E. Simmons Aug 1968

Development Of A Generalized Structural Dynamics Computer Program, Val E. Simmons

Theses and Dissertations

The purpose of this thesis was the development of a generalized structural-dynamics computer program to calculate the response of multi-degree-of-freedom systems. The user of this computer program, having a limited background in matrix algebra and vibrational analysis, can gain numerical and graphical information concerning the dynamic response of multi-degree-of-freedom structures. The user, with a minimal amount of FORTRAN experience, will find this thesis ideally suited for his needs.


A Concrete Pavement Without Transverse Joints [July 1968], Ronald D. Hughes Jul 1968

A Concrete Pavement Without Transverse Joints [July 1968], Ronald D. Hughes

Kentucky Transportation Center Research Report

In 1949, a 5.737-mile section of portland cement concrete pavement was constructed without the inclusion of transverse joints. The project, designated as Fl 239(4), is a section of US 31W located in Simpson County extending from the Tennessee line (Sta 9+11) to the south city limits of Franklin (Sta 311+40). The pavement is 22 feet wide, 8 inches thick, and is underlain by 1-1/2 inches of compacted No. 10 crushed limestone for insulation and leveling. Air-entraining cement was used and the concrete was placed with approximately 4-1/2 percent entrained air. One-half inch deformed tie bars were used in the longitudinal …


Semiconductor Nuclear Detectors, Lulio V. Guevara R. Jul 1968

Semiconductor Nuclear Detectors, Lulio V. Guevara R.

Electrical and Computer Engineering ETDs

For the last 8 years the development of nuclear detectors have been shown to have the best potentialities over the other kind of nuclear counters. In this report we studied in general the characteristics of semiconductor nuclear counters and then we experimented with two types of semiconductor detectors, the surface barrier and the diffused junction detectors. Several materials were analyzed for the fabrication of these detectors. Silicon was finally chosen because of its advantages over other materials for fabrication of semiconductor counters, such as low cost and grade of purity. Silicon wafers, n-and p- type, were obtained from Monsanto Company. …


Test 981: Ursus C-335 (Diesel), Nebraska Tractor Test Lab Jul 1968

Test 981: Ursus C-335 (Diesel), Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF TEST REPORT GENERAL CONDITIONS East tractor is a production model equipped for common usage. Power consuming accessories can be disconnected only when it is convenient for the operator to do so in practice. Additional weight can be added as ballast if the manufacturer regularly supplies it for sale. The static tire loads and the inflation pressures muse conform to recommendations in the Tire Standards published by the Society of Automotive Engineers. PREPARATION FOR PERFORMANCE RUNS The engine crank case is drained and refilled with a measured amount of new oil conforming to specifications in the operator’s manual. The …


Test 982: Ursus C-350 (Diesel), Nebraska Tractor Test Lab Jul 1968

Test 982: Ursus C-350 (Diesel), Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF TEST REPORT GENERAL CONDITIONS East tractor is a production model equipped for common usage. Power consuming accessories can be disconnected only when it is convenient for the operator to do so in practice. Additional weight can be added as ballast if the manufacturer regularly supplies it for sale. The static tire loads and the inflation pressures muse conform to recommendations in the Tire Standards published by the Society of Automotive Engineers. PREPARATION FOR PERFORMANCE RUNS The engine crank case is drained and refilled with a measured amount of new oil conforming to specifications in the operator’s manual. The …


Usu Remote Total Precipitation Telemetry Station, Duane G. Chadwick Jul 1968

Usu Remote Total Precipitation Telemetry Station, Duane G. Chadwick

Reports

A total precipitation catchment and telemetering device is described for use in mountainous regions. The precipitation transucer uses a weighing-type mechanism which has a variable inductor sensor.

The catchment system floats on springs and has negligible static friction. The radio transponder is powered by dry batteries. It responds upon coded interrogation, sending hydrologic or meteorological data through a mountaintop translator to a base station


Boiling Heat Transfer In The Presence Of Electric Fields, Ronald Francis Lovenguth Jun 1968

Boiling Heat Transfer In The Presence Of Electric Fields, Ronald Francis Lovenguth

Dissertations

The effects of a non-uniform, radial D.C. electric field on the natural convection and nucleate boiling regimes in saturated pool boiling and on the peak heat flux phenomenon were determined for trichlorotrifluoroethane, carbon tetrachloride, dichloromonofluoromethane and chloroform using as a heat transfer surface a 0.02 inch diameter platinum wire.

Bubble departure diameters for the nucleate boiling region were measured by photographic means as a function of the electric field intensity at the heat transfer surface.

The application of an electric field was found to have a significant effect on the natural convection mode of heat transfer and also the peak …


Viscosity-Density Correlation Of Newtonian Liquids, Melvin Leonard Druin Jun 1968

Viscosity-Density Correlation Of Newtonian Liquids, Melvin Leonard Druin

Dissertations

The viscosity of monatomic liquids was modeled by an equation derived from the kinetic theory of gases. Viscosities may be calculated from data on density and molecular weight of the liquid. In adapting this relationship to polyatomic liquids, a single correction factor was developed for each of five series of homologues; n-paraffins, n-1 -alkenes, n-alkylcyclohexanes, n-alkylbenzenes and n-alcohols, to account for the deviations of the calculated viscosities from those reported, extending over a one- to three-hundred degree range. The factor is a function of reduced temperature relative to the normal boiling point, TrB. A single equation for each …


The Mechanism Of Second Breakdown In Transistors, Eugene David Fabricius Jun 1968

The Mechanism Of Second Breakdown In Transistors, Eugene David Fabricius

Dissertations

The purpose of this dissertation is to examine the behavior of electrons and holes in a semiconductor or diode under conditions of high current density as a function of temperature, and to relate this behavior to the phenomenon of Second Breakdown. The approach used is that of magnetohydrodynamics, the electrons and holes being treated as a plasma "gas" embedded in the dielectric of the semiconductor.

This approach is unique in the following respects:

  1. This is the first attempt to explain second breakdown in terms of magnetohydrodynamics.
  2. This is the first time an explanation of pinching in a solid at room …


The Generalized Virial Equation Of State, Ghanshyam R. Patel Jun 1968

The Generalized Virial Equation Of State, Ghanshyam R. Patel

Dissertations

A generalized three parameter virial equation of state has been developed and tested for seven pure gases having different molecular characteristics. The equation has also been tested for more than thirteen binary gas mixtures using three different mixture rules. The final equation is as follows:

Z = 1 + B(T)/V + C(T)/V2 + D(T)/V3 + E(T)/V4 + VF(T)/eaV + VG(T)/ebV

The expressions for E(T), F(T), and G(T) along the critical isotherm were derived in terms of critical properties and two constants, a and b which appear in the sixth and seventh terms in the above …


The Plasticization Of 4-Methyl-Pentene-1 (Tpx-Rt-D30) Polymer With Petroleum Jelly, Joseph P. Mccann Jun 1968

The Plasticization Of 4-Methyl-Pentene-1 (Tpx-Rt-D30) Polymer With Petroleum Jelly, Joseph P. Mccann

Theses

The properties of TPX-RT-D30 (4-methyl-pentene-1 polymer) have been changed by blending petroleum jelly with the polymer. The polymer was blended in a Brabender apparatus with up to 40% by weight petroleum jelly (P.J.) at 270°C, pressed and quenched in water. Samples were die cut for the various tests. The polymer tensile properties (ASTM-638-64T) showed both a break and yield value in all ratios as compared to only a break value for the TPX-RT polymer. Breaking strength ranged from 4000 psi for pure TPX-RT down to 1000 psi at 40% P.J., with a leveling point of 2000 psi at 15% P.J. …


Critical Interaction Constants For Binary Gas Mixtures For Use In The Redlich-Kwong Equation Of State, Warren J. Biss Jun 1968

Critical Interaction Constants For Binary Gas Mixtures For Use In The Redlich-Kwong Equation Of State, Warren J. Biss

Theses

In this work, critical interaction constants were used to evaluate the interaction coefficients of the Redlich - Kwong constants for bin-ary gas mixtures. From these constants, the pressure - volume - temperature behavior of the mixtures was calculated using the Redlich - Kwong equation.

The critical interaction constants, T12 and P12 , were evaluated for binary mixtures by solving, simultaneously, two second degree equations relating terminal slopes for critical pressure loci and the mole fractions of the components present. The feasibility of this method was tested by calculating P-V-T data for binary mixtures and comparing this with values …


The Effect Of Nitrilotriacetic Acid Upon The Biodegradability Of Linear Alkyl Benzene Sulfonate, John D. Mckenna Jun 1968

The Effect Of Nitrilotriacetic Acid Upon The Biodegradability Of Linear Alkyl Benzene Sulfonate, John D. Mckenna

Theses

The effects of trisodium nitrilotriacetate (SKTA) and sodium tipolyphosphate (STPP) upon the biological degradation of linear alkyl benzene sulfonate (LAS) ware experimentally investigated by the chemical oxygen demand and methylene blue methods. It was found that when STPP was present with LAS, the degradation of the LAS was better than when alone in solution. It was also found that LAS in solution with SN TA was less degradable than LAS alone. The benzene ring of the MS appeared to degrade after most of the linear portion of the chain had already been degraded.


Effect Of Column Diameter On The Frequency Response Of Water Fluidized Beds, Edward C. Maiuro Jun 1968

Effect Of Column Diameter On The Frequency Response Of Water Fluidized Beds, Edward C. Maiuro

Theses

The effect of column diameter on the frequency response of water fluidized beds was investigated.

Studies were made on four columns ranging from four to ten inches in diameter. Water was used to fluidize the beds which consisted of spherical glass beads .0185 inches in diameter. A trace solution of sodium chloride was sinusoidally introduced into the beds. Inlet and outlet concentrations were continuously measured by an electrical conductivity recorder. Separate frequency response tests were conducted on the inlet calmning section in an attempt to obtain the frequency response of this region alone. Results of the tests were expressed as …


A Correlation Of Latent Heats And Densities Of Pure Organic Liquids From Known Vapor Pressure Data, Vincent J. Vasta Jun 1968

A Correlation Of Latent Heats And Densities Of Pure Organic Liquids From Known Vapor Pressure Data, Vincent J. Vasta

Theses

Employing the correlation developed by Kemme (5), which is based on a hole model for a liquid, relating vapor pressures with corresponding liquid densities and the number of carbon atoms in a molecular chain for a homologous series, correlation coefficients were established using multi-linear regression analysis on available literature data. This correlation was newly applied to several straight chain homologous series including the n-acids, formate esters and n-alkyl benzenes.

A second correlation developed by Kemme (5) relating vapor pressure, internal heat of vaporization and the number of carbon atoms for a homologous series was employed to determine correlation coefficients for …


The Optimization Of A Catalytic Methanol Reactor, Peter Wrampe Jun 1968

The Optimization Of A Catalytic Methanol Reactor, Peter Wrampe

Theses

The development of a computer program which determines the minimum space time of the methanol synthesis reactants is presented. Also, the optimum temperature profile along the catalytic reactor was predicted for a desired conversion at a given operating pressure, feed composition, and catalyst effectiveness factor.

The equilibrium conversion of methanol was determined at various reaction parameters. Rates of reaction were ascertained and maximized with respect to temperature for various conversions and given reaction parameters. The results, along with those obtained when the design equation was numerically integrated, were compared to published data. Equations were established for various sets of published …


Realization Of Transfer Impedances Using Distributed Rc Elements In A Common Ground Linvill Configuration, Walter Woronka Jun 1968

Realization Of Transfer Impedances Using Distributed Rc Elements In A Common Ground Linvill Configuration, Walter Woronka

Theses

One of several synthesis procedures available for the realization of a transfer admittance is that of Linvill. This synthesis procedure employs an active element, a negative impedance converter (NIC), to shift the poles of passive immittance functions from the negative real axis into the complex plane to realize the desired transfer immittance function.

The Linvill synthesis procedure is extended to networks containing cascaded distributed RC elements and the conditions which must be satisfied to realize a transfer impedance using these distributed elements are defined.