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Full-Text Articles in Engineering

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 ...


Analytical Investigation Of The Effect Of Material And Geometric Imperfections On Buckling Strength Of Spherical Shells , Rama Krishna Challa Jan 1995

Analytical Investigation Of The Effect Of Material And Geometric Imperfections On Buckling Strength Of Spherical Shells , Rama Krishna Challa

Retrospective Theses and Dissertations

Spherical shells are extensively used as structural elements. As they are subjected to different loading conditions, compressive membrane forces develop causing failure due to compressive stability. In order that the shells perform their design function adequately, sufficient design margins should exist. These design margins are established by means of experimental tests and numerical analysis. Comparisons between classical, theoretical and experimental results for spherical shells subjected to external pressure loading demonstrated large discrepancies. These discrepancies are attributable to material and geometric imperfections resulting from fabrication methods.;Sufficient design information with respect to the imperfections is required to perform numerical analyses. The ...


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 ...


Measuring And Modeling Alachlor Dissipation In Soil , Dee Anna Jo Weed Jan 1995

Measuring And Modeling Alachlor Dissipation In Soil , Dee Anna Jo Weed

Retrospective Theses and Dissertations

Field and laboratory experiments evaluated the overall dissipation of alachlor (2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl) acetamide) and the effect of no-till and chisel-plow tillages on alachlor leaching and dissipation. In the top 30-cm layer of field soil, the time to 50% dissipation (half-life) was 2 to 3 d, and the time to 90% dissipation ranged from 17 to 30 d. In no-till soil, alachlor dissipated slightly faster, and more was transported into the 10-to-30-cm soil layer. The tillage effect depended on weather that favored movement into and dissipation within the soil, rather than dissipation on plant residues and the soil ...


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.


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 ...