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Full-Text Articles in Engineering

Nondestructive Dynamic Load Testing Of Bridges Using Strain Sensors, Suzanne Boland Dec 1995

Nondestructive Dynamic Load Testing Of Bridges Using Strain Sensors, Suzanne Boland

Theses

This thesis investigates the use of nondestructive bridge load testing utilizing strain sensing equipment. Nondestructive bridge load testing has not been used extensively due to lack of expertise and perceived high cost. It can, however, play a key role when an existing bridge needs to be evaluated. Since most evaluation techniques tend to be conservative, the results from such an evaluation may not represent the real properties of the structural members. The true properties of an existing bridge can be identified using the results from nondestructive static and dynamic load testing. The procedures used to identify a structure with the ...


Anaerobic Digestion And Acid Hydrolysis Of Nitrocellulose, Fong-Jung Tai Dec 1995

Anaerobic Digestion And Acid Hydrolysis Of Nitrocellulose, Fong-Jung Tai

Dissertations

In this investigation, studies were conducted to evaluate the biodegradation of nitrocellulose in anaerobic batch reactors with and without the supplemental carbon inducers, such as cellulose, cellobiose, and lactose. Results from the anaerobic study show that degradation of nitrocellulose alone is difficult and that nitrocellulose degradative enzymes could be induced by the three inducers tested. As high as 48.91% conversion could be obtained at Cellulose/Nitrocellulose ratio of 1 to I. Studies also indicated that type 20 and 50 celluloses would be more effective and optimum pH was about 6.4 in biodegradation of nitrocellulose. Three testing systems, namely ...


A Study On The Causes Of Variations In Transmissivity And Storativity During Pump Tests At Asylum Lake, Paul Joseph Pare Dec 1995

A Study On The Causes Of Variations In Transmissivity And Storativity During Pump Tests At Asylum Lake, Paul Joseph Pare

Master's Theses

Over a two year period, Western Michigan University ran a number of pump tests in the Asylum Lake Area in Kalamazoo, Michigan. The transmissivities and storativities calculated from these tests differed significantly from well to well in any particular test, and from pump test to pump test. Utilizing the computer programs AQTESOLV 3.0 and Aquifer Parameter Estimator, a number of T and S values were calculated. After analysis of the results, the following conclusion was drawn. The main reason for the deviations in the T and S values arose from the mixing of the results of numerous methods (some ...


A Theoretical Analysis Of Volatile Contaminant Removal By The Pneumatic Fracturing Process, Yuan Ding Oct 1995

A Theoretical Analysis Of Volatile Contaminant Removal By The Pneumatic Fracturing Process, Yuan Ding

Dissertations

A mathematical model that simulates the process of contaminant removal from a pneumatically induced fracture within a porous medium is presented. It includes: (1) model development; (2) parameter evaluation; (3) statistical sensitivity analysis; and (4) model validation.


Fundamentals Of Adhesion Of Organic Compounds And Aqueous Cleaning Of Glass And Metal Surfaces : Applications In The Pharmaceutical And Chemical Industries, Michel J. De Ruijter May 1995

Fundamentals Of Adhesion Of Organic Compounds And Aqueous Cleaning Of Glass And Metal Surfaces : Applications In The Pharmaceutical And Chemical Industries, Michel J. De Ruijter

Theses

In this thesis we studied the physics and chemistry of the adhesion of various classes of organic compounds to glass and stainless steel surfaces, by using diagnostic aqueous cleaning solutions and other techniques. We defined the thermodynamic requirements for aqueous cleaning based on extensive experimental and theoretical work. Novel cleaning diagrams are introduced, based on electrostatic interactions between organic compounds and solid surfaces, to facilitate the design of aqueous cleaning systems. We studied the mass transfer parameters for selected situations. The electrochemical Pourbaix-diagrams were used to explain the effect of hydrogen peroxide added to aqueous solutions and to avoid corrosion ...


Composite Beam Analogy Fracture Model (Cbafm) : A Non-Linear Fracture Mechanics Model For Concrete, Mohammed Enamul Haque May 1995

Composite Beam Analogy Fracture Model (Cbafm) : A Non-Linear Fracture Mechanics Model For Concrete, Mohammed Enamul Haque

Dissertations

The main objective of this dissertation is to develop a simple non-linear fracture mechanics model for the determination of fracture mechanics parameters for concrete, such as fracture process zone length (rp), critical fracture energy release rate (Gic), critical stress intensity factor (KO and fracture energy (GF). The fracture process zone (FPZ) is modeled as a damaged non-elastic cohesive band where the extent of damage due to microcracking varies from no damage at the boundary of FPZ to complete crack surface separation at the notch or macro-crack tip. The proposed method can predict theoretically both the pre-peak and post-peak load versus ...


Water Quality Model For South Slough, Coos Bay, Oregon, Holly Kay Juza May 1995

Water Quality Model For South Slough, Coos Bay, Oregon, Holly Kay Juza

Dissertations and Theses

The South Slough Estuary is located off Coos Bay along the southern coast of Oregon. It is divided into two channels that meet and continue to Coos Bay at the Charleston Harbor. There are six major contributing streams to South Slough. After rainfall events, the level of coliform bacteria in the slough increases because of stream bacteria loading. This is due to cattle grazing in the drainage areas, failed septic systems from private homes, and sewage sludge applied to the County landfill, which drains into the slough. The Oregon Health Division has enforced a Sanitation Management Plan for Commercial Shellfish ...


Improved Finite Analytic Methods For Solving Advection-Dominated Transport Equation In Highly Variable Velocity Field, Wei Cuifeng Apr 1995

Improved Finite Analytic Methods For Solving Advection-Dominated Transport Equation In Highly Variable Velocity Field, Wei Cuifeng

Dissertations and Theses

Solute transport studies frequently rely on numerical solutions of the classical advection-diffusion equation. Unfortunately, solutions obtained with traditional finite difference and finite element techniques typically exhibit excessive numerical diffusion or spurious oscillation when advection dominates, especially when velocity field is highly variable. One recently developed technique, the finite analytic method, offers an attractive alternative. Finite analytic methods utilize local analytic solutions in discrete elements to obtain the algebraic representations of the governing partial differential equations, thus eliminating the truncation error in the finite difference and the use of approximating functions in the finite element method. The finite analytic solutions have ...


Evaluation Of Automatic Vehicle Specific Identification (Avsi) In A Traffic Signal Control System , Alireza Kamyab Jan 1995

Evaluation Of Automatic Vehicle Specific Identification (Avsi) In A Traffic Signal Control System , Alireza Kamyab

Retrospective Theses and Dissertations

Automatic Vehicle Specific Identification (AVSI) is a generic name for advanced vehicle detection systems. By automating the identification of vehicles by sensing the presence of vehicles with roadside detection sites or readers, AVSI is assumed to provide vehicle specific information in traffic signal control systems;In the application of AVSI to traffic signal control systems, as a vehicle passes a reader site, the reader records the arrival time and type of the detected vehicle. The reader would then send the information received to a local microprocessor-based traffic signal controller. The controller's built-in signal control logic would then use the ...


Modeling Recession And Low Flow Characteristics Of Iowa Streams , Ahmad Ali Raaii Jan 1995

Modeling Recession And Low Flow Characteristics Of Iowa Streams , Ahmad Ali Raaii

Retrospective Theses and Dissertations

Available mean daily streamflow data from 143 gaging stations were initially analyzed to characterize recessions and low flows of Iowa streams. The period of record varies between 10 and 115 years for different stations. A computerized mathematical model was used to derive two master recession curves (MRC's)--one for winter and the other for summer--and to calculate the median storage delay factor (K med) for each individual station. These factors were used to estimate the diffusivity of the aquifer(s) contributing base flow to each stream;The MRC's can be used to forecast the general behavior of streams ...


Surface And Sub-Surface Ablation Cell Design For Remote (Robotic) Radioactive Soil Analysis Using Laser Ablation-Inductively Coupled-Atomic Emission Spectrometry/Mass Spectrometry La-Icp-Aes/Ms , Reza Bashirzadeh Jan 1995

Surface And Sub-Surface Ablation Cell Design For Remote (Robotic) Radioactive Soil Analysis Using Laser Ablation-Inductively Coupled-Atomic Emission Spectrometry/Mass Spectrometry La-Icp-Aes/Ms , Reza Bashirzadeh

Retrospective Theses and Dissertations

There are approximately 1800 uncontrollable hazardous waste sites across the United States. The Department of Energy (DOE) is responsible for cleaning up several of these sites that were contaminated as a result of producing weapon-grade nuclear fuels in different states since the 1940s. Site characterization is the first and a very critical step in the remediation program of a radioactive contaminated site. During this process, all the necessary information about location, level, and chemical composition of the contaminated sites must be collected for the clean up planning. Ames Laboratory, one of the U.S. Department of Energy sites, has adopted ...


Flocculation Kinetics Using Dual Coagulants: Effects Of Temperature, Addition Sequence, Rapid Mixing, And Sulfate , Bashaar Yakoub Ammary Jan 1995

Flocculation Kinetics Using Dual Coagulants: Effects Of Temperature, Addition Sequence, Rapid Mixing, And Sulfate , Bashaar Yakoub Ammary

Retrospective Theses and Dissertations

The effects of temperature, rapid mixing time and intensity, sulfate, and coagulant addition sequence of dual coagulants on the flocculation kinetics were studied. Either ferric nitrate alone or a cationic polymer alone or in combination as dual coagulants were used. The flocculation kinetics were monitored using mainly a Photometric Dispersion Analyzer (PDA). An Automatic Image Analyzer was also used in a limited number of experiments to monitor the flocculation kinetics. Kaolinite clay (with four concentrations: 5, 25, 50, and 100 mg/L) suspended in distilled water with added salinity was used at two temperatures (5 or 23°C) and two ...


Effect Of Various Mixing Devices And Patterns On Flocculation Kinetics In Water Treatment , Md. Wahid Sajjad Jan 1995

Effect Of Various Mixing Devices And Patterns On Flocculation Kinetics In Water Treatment , Md. Wahid Sajjad

Retrospective Theses and Dissertations

This research was designed to investigate the effects of different mixing variables on flocculation kinetics of kaolinite clay suspension at both warm and cold water temperatures (23°C and 5°C) using alum and ferric nitrate under a number of physico-chemical conditions. The following work was performed during this experimental study: (1) G versus rpm curves for different impellers were developed using calculated power based on measured torque. The torque was measured by a rotating torque meter using a photographic technique. (2) The effects of impeller geometry, rapid mixing intensity and pattern, concentration of coagulant dosing solution, coagulant injection pattern ...


Anaerobic Sequencing Batch Reactor Treatment Of Low Strength Wastewater , Udeme James Ndon Jan 1995

Anaerobic Sequencing Batch Reactor Treatment Of Low Strength Wastewater , Udeme James Ndon

Retrospective Theses and Dissertations

The treatment of low strength wastewater at various temperatures and hydraulic retention times in the anaerobic sequencing batch reactor (ASBR) was studied. The studies involved the use of four identical, laboratory scale anaerobic sequencing batch reactors (ASBRs), each having a working volume of six liters. One of the reactors was maintained at a 48 hour hydraulic retention time HRT, the second at a 24 hour HRT, the third at a 16 hour HRT and the fourth at a 12 hour HRT. A synthetic substrate (non fat dry milk; NFDM) was treated at concentrations of 1000, 800, 600 and 400 mg ...


Resuspension Behavior Of Natural Estuarine Sediments, Chang-Hee Lee Jan 1995

Resuspension Behavior Of Natural Estuarine Sediments, Chang-Hee Lee

Dissertations, Theses, and Masters Projects

The resuspension behavior of natural estuarine sediments was studied using the VIMS Sea Carousel, a benthic annular flume. The bed shear stresses produced by the flume were measured by a hot-film sensor mounted flush on the bottom of a laboratory version of the Carousel under a clear-water and flat-bottom condition. Measurements showed a reasonably uniform bed shear stress across the channel and agreed with the relationship &\tau\sb{lcub}\rm b{rcub}=0.011\Omega\sp{lcub}1.69{rcub},& where &\Omega& = ring speed (rpm) and &\tau\sb{lcub}\rm b{rcub}& = spatially-averaged bed shear stress (N/m&\sp2&), predicted ...


Micromechanics Of Hot Mix Asphalt Material Formulation And Numerical Simulation, Kuo-Neng G. Chang Jan 1995

Micromechanics Of Hot Mix Asphalt Material Formulation And Numerical Simulation, Kuo-Neng G. Chang

Dissertations

Hot Mix Asphalt (HMA), a highway and airfield pavement material, is heterogeneous, granular, and composite. It is traditionally modeled as a homogeneous material using continuum mechanics or semi-empirical methods. As a result, the above models either neglect or over-simply component reactions, failing to predict field performance problems resulting from particle segregation. This research presents micromechanical modeling, a novel approach that accounts for the components.

A micromechanical model is developed for HMA by modeling it as an assembly of asphalt cement coated particles. The asphalt cement is modeled as a viscoelastic material. To represent asphalt cement, several viscoelastic elements (i.e ...


Linear Scheduling Model: The Development Of A Linear Scheduling Model With Micro Computer Applications For Highway Construction Project Control , David John Harmelink Jan 1995

Linear Scheduling Model: The Development Of A Linear Scheduling Model With Micro Computer Applications For Highway Construction Project Control , David John Harmelink

Retrospective Theses and Dissertations

This thesis describes a new approach to the problem of scheduling highway construction type projects. The technique can accurately model linear activities and identify the controlling activity path on a linear schedule. Current scheduling practices, are unable to accomplish these two tasks with any accuracy for linear activities, leaving planners and managers suspicious of the information they provide. Basic linear scheduling is not a new technique, and many attempts have been made to apply it to various types of work in the past. The technique has never been widely used however, because of the lack of an analytical approach to ...


Buckling Assessment Of Axially Loaded Cylindrical Shells With Random Imperfections, Sherif Saleh Safar Aly Jan 1995

Buckling Assessment Of Axially Loaded Cylindrical Shells With Random Imperfections, Sherif Saleh Safar Aly

Retrospective Theses and Dissertations

The buckling strength of axially loaded cylindrical shells is greatly affected by geometric imperfections. Due to the difference between test results and classical theory solution, current codes of practice require the application of knockdown factors to the classical buckling load. Another approach is to conduct a rigorous analysis incorporating geometric and material imperfections. However, the shape of imperfections that result in the minimum buckling load is questionable. In this work, the effect of random geometric imperfections on the buckling strength of axially loaded cylinders was investigated using the finite element method. Geometric imperfections were modeled by a series of cosine ...


An Assessment Improving Employee Attitudes And Job Satisfaction Through Total Quality Management Implementation, Sara Anne Birkland Jan 1995

An Assessment Improving Employee Attitudes And Job Satisfaction Through Total Quality Management Implementation, Sara Anne Birkland

Retrospective Theses and Dissertations

No abstract provided.