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Articles 33451 - 33480 of 39915

Full-Text Articles in Engineering

A Comparative Analysis Of Three Water Treatment Programs For Cooling Tower Systems, Jeffry W. Shea Sep 1991

A Comparative Analysis Of Three Water Treatment Programs For Cooling Tower Systems, Jeffry W. Shea

Theses and Dissertations

This study investigated the cost and effectiveness of three cooling tower water treatment programs. The programs studied were an acid program developed at WPAFB, a commercial solubilizer program manufactured by Lombardi, Inc, and a crystal modifier program developed by Dias, Inc. The experiment ran for 60 days at which time cost and effectiveness data were collected. Cost comparison was evaluated on the basis of tower performance in MBtu. The costs considered in this experiment were water costs, sewer costs, and chemical costs. All costs were recorded and totaled, then divided by the tower's performance. The effectiveness of each treatment method …


Evaluation Of Managerial Challenges Created By Acceleration Of The Installation Restoration Program, Robert L. Vinson Iii Sep 1991

Evaluation Of Managerial Challenges Created By Acceleration Of The Installation Restoration Program, Robert L. Vinson Iii

Theses and Dissertations

This study investigates the distribution of managerial tasks related to the Installation Restoration Program (IRP). Initiated in 1986, the IRP is the DoD program to identify and clean-up hazardous waste sites. Study areas include current distribution of managerial tasks, changes in task distribution needed to accelerate the program, and potential resource constraints. Additionally, the study considers how acceleration of Army and Navy restoration programs could impact the Air Force IRP. The study reveals IRP management is heavily centralized at MAJCOM with most technical work being performed through contracts with service centers. Individual bases have little direct involvement in the program. …


Applying The Theory Of Constraints To A Base Civil Engineering Operations Branch, Bryan K. Zachmeier Sep 1991

Applying The Theory Of Constraints To A Base Civil Engineering Operations Branch, Bryan K. Zachmeier

Theses and Dissertations

The purpose of this thesis is to introduce the Civil Engineering manager to the Theory of Constraints management philosophy and to show how to apply this process of ongoing improvement to the Operations Branch. One of the reasons for the success of Theory of Constraints in commercial firms is that it provides all levels of management the ability to find simple solutions for bridging the gap between local and global issues. This 'bridge' is built by clearly defining the goal of the organization and using performance measurements capable of predicting the effect of local decisions and actions on the goal. …


Industrial Wastewater Management Practices In Air Force Logistics Command, Patrick J. Smith Sep 1991

Industrial Wastewater Management Practices In Air Force Logistics Command, Patrick J. Smith

Theses and Dissertations

The selection of a model plant was based upon criteria established by a review of current literature. The criteria were permit compliance, plant performance, and the adoption of pollution prevention as a corporate environmental philosophy. In this study, private sector firms were examined to identify the best industrial wastewater management practices using a Total Quality Management (TQM) tool called benchmarking. The data gathering process consisted a survey of water pollution control organizations, and a survey of benchmark candidates. The purpose of surveying water pollution control organizations was to objectively identify possible benchmark candidates. A questionnaire was then used to gather …


Ccfss News August 1991, Wei-Wen Yu Center For Cold-Formed Steel Structures Aug 1991

Ccfss News August 1991, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.


Evaluation Of Headwalls And Outlets For Geocomposite Edge Drains On I-75 And I-71, L. John Fleckenstein, David L. Allen, Jack A. Harison Aug 1991

Evaluation Of Headwalls And Outlets For Geocomposite Edge Drains On I-75 And I-71, L. John Fleckenstein, David L. Allen, Jack A. Harison

Kentucky Transportation Center Research Report

Longitudinal, round, perforated pipe edge drains have been used along Kentucky roadways for approximately two decades. Panel (fin) edge drains were first used in Kentucky in 1984. Most of these edge drains were installed on the Interstate and Parkway systems.

Several problems related to the drains have been noted in the last seven years. A number of these problems have been observed to be related to flexible outlet pipes and headwalls.

A recent study was initiated to evaluate headwalls and outlets on I-75 from Lexington, Kentucky to Cincinnati, Ohio (approximately 70 miles) and on I-71 from Louisville, Kentucky to I-75 …


Comparing Simulated And Experimental Hysteretic Two-Phase Transient Fluid Flow Phenomena, R. J. Lenhard, J. C. Parker, Jagath J. Kaluarachchi Aug 1991

Comparing Simulated And Experimental Hysteretic Two-Phase Transient Fluid Flow Phenomena, R. J. Lenhard, J. C. Parker, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

A hysteretic model for two-phase permeability (k)-saturation (S)-pressure (P) relations is outlined that accounts for effects of nonwetting fluid entrapment. The model can be employed in unsaturated fluid flow computer codes to predict temporal and spatial fluid distributions. Consideration is given to hysteresis in S-P relations caused by contact angle, irregular pore geometry, and nonwetting fluid entrapment effects and to hysteresis in k-Srelations caused by nonwetting fluid entrapment effects. An air-water flow experiment is conducted with a 72-cm vertical soil column where the water table is fluctuated to generate scanning S-P paths. Water contents are measured via a gamma radiation …


Optimal Aquifer Planning With Salt Water Boundary, Richard C. Peralta, Shu Takahashi Jul 1991

Optimal Aquifer Planning With Salt Water Boundary, Richard C. Peralta, Shu Takahashi

Civil and Environmental Engineering Faculty Publications

Optimal sustained-yield pumping strategies were developed for the irrigated and industrialized eastern shore of the Great Salt Lake. The combined optimization and simulation model, in which steady-state, finite difference, quasi-three-dimensional ground water flow equations were embedded as constraints, computes the optima,! distribution for sustainable annual ground water pumping rates for alternative scenarios. 1. The model deals with management of a large, multilayer, confined/unconfined (linear/nonlinear) aquifer system. 2. The research can help manage water in the study area where· the demand for water of sufficient quality and quantity is increasing due to urbanization.


Engineering Estimates And Fhwa Accuracy Criterion, David Q. Hunsucker Jul 1991

Engineering Estimates And Fhwa Accuracy Criterion, David Q. Hunsucker

Kentucky Transportation Center Research Report

The Federal Highway Administration requires the construction cost estimate of the highway engineer to be a projection of the low bid, and be within +/- 10 percent of the low bid for at least 50 percent of the projects awarded. Construction cost estimates developed by the Estimating Staff of the Kentucky Department of Highways have not always met this criterion in years past.

The Estimating Staff of the Kentucky Department of Highways use an actual cost approach to generate construction cost estimates. It was concluded that the Department's estimating staff possess the ability to do very thorough and accurate work. …


Protective Coating Program Final Report, James E. Funk, Theodore Hopwood Ii, Donald G. Hartman, Christopher M. Oberst, Rick D. Saylor, Anantha R. Sethuraman Jul 1991

Protective Coating Program Final Report, James E. Funk, Theodore Hopwood Ii, Donald G. Hartman, Christopher M. Oberst, Rick D. Saylor, Anantha R. Sethuraman

Kentucky Transportation Center Research Report

This program consists of two primary segments: 1) installing an environmental monitoring station at the Toyota marshalling yard at Georgetown, Kentucky, and 2) conducting laboratory and field tests of paint and wax-coated painted specimens to assess the protection against acid rain damage afforded by a protective transient coating.


Summary Of Results Of 1990 Field And Laboratory Evaluations Of Pavement Marking Materials (Sashto Regional Test Facility), Kentucky Transportation Center Jul 1991

Summary Of Results Of 1990 Field And Laboratory Evaluations Of Pavement Marking Materials (Sashto Regional Test Facility), Kentucky Transportation Center

Kentucky Transportation Center Research Report

This report summarizes the results of data collected as part of the 1990 field and laboratory evaluations of pavement marking materials for the SASHTO Regional Test Facility. The purpose of the Regional Test Facility (RTF) is to minimize the amount of field and laboratory research testing of specific types of materials. This is accomplished by combining efforts in an organized manner to reduce the monetary and man-hour requirements of both the states and industry. A RTF for the twelve SASHTO states was approved at the 1988 SASHTO convention. The twelve SASHTO states are Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, …


Engineering Soils Map Of Washington County, Indiana, Wei-Yao Chen Jul 1991

Engineering Soils Map Of Washington County, Indiana, Wei-Yao Chen

JTRP Technical Reports

No abstract provided.


Parallel-Vector Design Sensitivity Analysis In Structural Dynamics, Yongxing Zhang Jul 1991

Parallel-Vector Design Sensitivity Analysis In Structural Dynamics, Yongxing Zhang

Civil & Environmental Engineering Theses & Dissertations

In this study, the design sensitivity analysis is for the purpose of providing constraint derivative information for structural optimization under dynamic loads. Various existing formulations are reviewed, and the direct differentiation method is justified as the best one for design sensitivity analysis in structural dynamics. An alternative formulation for design sensitivity analysis with direct differentiation method is developed. The alternative formulation works efficiently with the reduced system of dynamic equations, and it eliminates the need for expensive and complicated eigenvector derivatives, which is required in the existing reduced system formulation. The relationship of the alternative formulation and the existing reduced …


Parallel-Vector Computation For Geometrically Nonlinear Frame Structural Analysis And Design Sensitivity Analysis, Majdi A. Baddourah Jul 1991

Parallel-Vector Computation For Geometrically Nonlinear Frame Structural Analysis And Design Sensitivity Analysis, Majdi A. Baddourah

Civil & Environmental Engineering Theses & Dissertations

Parallel-vector algorithms are presented for solving the geometrically nonlinear structural problems and obtaining design sensitivity information. A new algorithm is also presented for parallel generation and assembly of the finite element stiffness and mass matrices. The presented assembly algorithm is based on a node-by-node approach rather than the more conventional element-by-element approach. Three different methods, Newton Raphson, Modified Newton Raphson, and the BFGS, are used in the analysis of the nonlinear structural problems. A study is made to determine the performance of each of the mentioned methods in a parallel-vector computer environment. Medium to large-scale, practical problems are solved to …


An Experimental Study On Anisotropic Behavior Of Granular Materials, Jong Woon Choi Jul 1991

An Experimental Study On Anisotropic Behavior Of Granular Materials, Jong Woon Choi

Civil & Environmental Engineering Theses & Dissertations

Two types of mixtures of glass bead assemblies (large beads and small beads) were used to investigate the source of the anisotropy of granular materials in volume change behaviors during shearing process. Most tests (7 series) were conducted in the conventional triaxial device while a series of the experiments were in the hollow cylinder test device. All the specimens were first isotropically consolidated up to 137.9 kPa and were subjected to shearing in triaxial compression and triaxial extension modes with a constant effective mean normal stress (137.9 kPa). The test results indicated that all the specimens had a strong but …


Bs News Jul 1991

Bs News

Building Services Engineering

No abstract provided.


Optimal Sustained-Yield Groundwater Pumping Strategy For The East Shore Area, Utah, Shu Takahashi, Richard C. Peralta Jun 1991

Optimal Sustained-Yield Groundwater Pumping Strategy For The East Shore Area, Utah, Shu Takahashi, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Optimal sustained-yield pumping strategies were developed for the irrigated and industrialized eastern shore of the Great Salt Lake. The combined optimization and simulation model contains steady-state, finite difference, quasi-three-dimensional, groundwater flow equations embedded as constraints. The model computes the optimal spatial distribution of sustainable annual groundwater pumping rates for alternative scenarios. The addressed aquifer is a multilayer and confined/unconfined (linear/nonlinear) system. The research can help manage water in the study area, where the demand for water of sufficient quality and quantity is increasing due to urbanization.


Tensile Strength Of Welded Connections, Wei-Wen Yu, Roger A. Laboube Jun 1991

Tensile Strength Of Welded Connections, Wei-Wen Yu, Roger A. Laboube

CCFSS Library (1939 - present)

PREFACE The tensile strength of an arc spot weld is given only limited attention in the current edition of the AISI Specification for the Design of Cold-Formed Steel Structural Members. To broaden the design engineer's understanding of the behavior of arc spot welds, and to expand the specification's application for arc spot welds, the American Iron and Steel Institute, in 1989, initiated a research study at the University of Missouri-Rolla. The UMR research consisted of a comprehensive literature review, and experimental study which comprised of over 260 individual connection test specimens. The test specimen selection enabled the investigation of the …


Flexural Behavior Of Web Elements With Openings, Roger A. Laboube, Wei-Wen Yu, K. D. Batson Jun 1991

Flexural Behavior Of Web Elements With Openings, Roger A. Laboube, Wei-Wen Yu, K. D. Batson

CCFSS Library (1939 - present)

INTRODUCTION The purpose of this phase of the research has been to investigate the flexural behavior of C-shaped members with web openings. Three common industry standard C-sections were tested as outlined in the first progress report. The web openings were located at 24 inches on center as illustrated in Fig. 1. Each test specimen was subjected to two point loads until the ultimate flexural strength of the member was obtained. This report summarizes the test procedure and results of the research to date.


Bearing Capacity Analysis Of Pavements, Tommy C. Hopkins Jun 1991

Bearing Capacity Analysis Of Pavements, Tommy C. Hopkins

Kentucky Transportation Center Research Report

A multilayered, mathematical model for analyzing the ultimate bearing capacity of soil subgrades and asphalt pavements is presented. Theoretical considerations and mathematical derivations of limit equilibrium equations, based on plasticity principles, for analyzing the ultimate bearing capacity of soil subgrades and partially completed asphalt pavements, and the extension of these equations to the analyses of asphalt pavements composed of multiple layers, are presented. The model is unique since shear strength parameters, Φ and c, (the angle of internal friction and cohesion, respectively) are used to describe each layer of material of the pavement structure and a factor of safety against …


Evaluation Of Modified Asphalt Mixtures, Kamyar C. Mahboub, Amy Simpson Jun 1991

Evaluation Of Modified Asphalt Mixtures, Kamyar C. Mahboub, Amy Simpson

Kentucky Transportation Center Research Report

The primary objective of this study was to conduct a comparative analysis on various modified asphalt mixture systems in order to determine their suitability for conditions that are commonly encountered in Kentucky.

Several modified asphalt mixture systems were selected for laboratory and field testing (one-mile long field test section on KY 80, Pulaski County). These systems included the following asphalt mixtures: Control, Vestoplast, Polypropylene Fiber, Gilsonite, PMAC #1, Polyester Fiber, and PMAC #2. Laboratory testing included: Marshall stability and flow, mixture air voids and density, indirect tensile strength, moisture damage susceptibility, freeze-thaw damage susceptibility, resilient modulus, and repeated load permanent …


Bs News Jun 1991

Bs News

Building Services Engineering

No abstract provided.


Load-Deformation Behavior Of Reinforced Fibrous Concrete Beams, Rujun He May 1991

Load-Deformation Behavior Of Reinforced Fibrous Concrete Beams, Rujun He

Theses

This study deals with the load-deformation behavior of steel fiber reinforced concrete beams.

Theoretical development of moment-curvature and load-deformation relationships is presented in this paper. It is based on the assumption that the failure at a section occurs either when the force equilibrium equation is violated or when the concrete elements start to get crushed in the member. The complete stress-strain relationship of plain fibrous concrete in reference [2] was used in this study.

A special computer program is presented herein to carry out the theoretical studies of load-deformation behavior of simply supported beam under two-point loading. The validity of …


Evaluation Of Cracking Mechanism In Fiber Reinforced Concrete Subjected To Impulsive Loading, Rajendra K. Navalurkar May 1991

Evaluation Of Cracking Mechanism In Fiber Reinforced Concrete Subjected To Impulsive Loading, Rajendra K. Navalurkar

Theses

This thesis presents an experimental evaluation of J-Integral for plain and fiber reinforced concrete subjected to impact loading. A computer assisted instrumented Charpy test system was employed in applying the impact loads. Twenty two three point bend specimens with two different notch lengths were tested under impact velocity of 43.29 in/sec. Development and testing of a new fiber optic sensor, for the determination of internal Crack Tip Opening Displacements (CTOD) in concrete is described.

Evaluation of JIC values from experimental results of this study indicate that JIC can be characterized as a material constant. The Dynamic value of …


Influence Of Fly Ash Characteristics On Compressive Strength Of Mortar, Poorna Rajeswari Ratnaweera May 1991

Influence Of Fly Ash Characteristics On Compressive Strength Of Mortar, Poorna Rajeswari Ratnaweera

Theses

Fly ash-cement mortar, constituting of fly ash, cement and sand, vary in strength characteristics from conventional cement sand mortar. Out of many parameters effecting the compressive strength characteristics of fly ash-cement mortar, four were investigated in this study. They are particle size and its distribution, weathering of fly ash, moisture content & water/cementitious ratio and mix proportioning.

Class F fly ashes from three different sources were used in this study. The particle size distribution and moisture content of fly ashes were investigated by standard ASTM methods. The unconfined compressive strength of mortar was obtained by testing 2"x2"x2" test cubes conforming …


Water Treatment Plant Sludge As Sanitary Landfill Liner, Sinnadurai Sockanathan May 1991

Water Treatment Plant Sludge As Sanitary Landfill Liner, Sinnadurai Sockanathan

Theses

This study was performed to explore the possibility of using the sludge waste from the water treatment plant at Boonton New Jersey as a containment material for the sanitary landfills or as a fill material. At present natural clay is being used as a containment liner for the landfills and by using this sludge, recycling of a waste product will be achieved in an economical manner.

As a first part of this studies, efforts were made to utilize the liquid sludge having a solid content of about 3%. Attempts to dewater the liquid sludge to a workable mix by adding …


Determination Of Water-Cement Ratio In Cement Paste By Atomic Absorption Spectrometry, Jiong Zhao May 1991

Determination Of Water-Cement Ratio In Cement Paste By Atomic Absorption Spectrometry, Jiong Zhao

Theses

As one of the important characteristics of concrete, water-cement ratio controls porosity and thus strength and corrosion resistance of hardened concrete.

This paper presents a laboratory observation for determination of water-cement ratio of fresh concrete for quality control and quality assurance. The atomic absorption spectrophotometer and the flouresence spectrophtometer were used to determine the calcium concentration in cement solution of various water-cement ratio. The level of water-cement ratio investigated ranged from 0.4 to 0.55 which covers the most range of water-cement ratios in present practice. The result of lab experiments shows an immediate relation between the water-cement ratio and the …


Automated Determination Of Air Content In Hardened Concrete, Anita R. Navalurkar May 1991

Automated Determination Of Air Content In Hardened Concrete, Anita R. Navalurkar

Theses

An automated system was developed for the microscopic determination of air content and the related parameters in hardened concrete using the principles of Image Analysis and Computer Technology. Slices taken from the concrete specimen were viewed through a microscope with 40X magnification. The magnified image of the concrete slice is digitized by an Image Analyzing Software. Methodologies were developed for analysis of the digitized image and determination of air content and the required parameters. The automated system included a motorized positioner which translated microscope stage in a frame by frame sequence so that the whole image is digitized. Several tests …


Solidification/Stabilization Of Chromium Contaminated Soil Using Cement And Fly Ash, Arunkumar Sripathi May 1991

Solidification/Stabilization Of Chromium Contaminated Soil Using Cement And Fly Ash, Arunkumar Sripathi

Theses

Chromium, when present in the soil, can cause serious health hazards. Toxicity depends upon the concentration in the soil. Chromium in soil has become a major problem in some sites and a method must be developed so that it can be treated or disposed of in a safe manner.

In this research experiments are conducted to check whether the chromium contaminated soil can be solidified and landfilled in a safe way. To have a control over the amount of chromium present in the soil, pure soil (free from chromium contamination) was used and chromium was added in different proportion.

Another …


Evaluating The Role Of Geogrids In The Rehabilitation Of Cracked Dams Via Numerical Techniques, Kelly Dean Uhacz May 1991

Evaluating The Role Of Geogrids In The Rehabilitation Of Cracked Dams Via Numerical Techniques, Kelly Dean Uhacz

Dissertations and Theses

Collapse and cracking of debris earth embankment dams is a serious problem in areas of the arid Western United States. The use of geogrids is evaluated in this thesis as a possible solution to prevent or reduce the amount of damage to the structures from collapse and cracking.

An apparatus was designed, constructed, and instrumented to electronically acquire data to evaluate the behavior of geogrids during pullout tests under various normal stresses. The pullout tests were also modelled using numerical techniques to correlate physical test data with numerical test data. Understanding the behavior of the geogrid, in both the physical …