Engineering Commons^™

Bond And Fatigue Characteristics Of High-Strength Cement-Based Composites, Somboon Chimaphant

Dissertations

The results of a series of tests on a variety of high strength cementitious composites yield a model from which an empirical equation of general normalized pull-out stress vs. pull-out displacement relationship is developed. A new variable named the "Brittleness Index" is defined and used in the proposed equation. Additionally, the concept of maximum strain is used to predict the fatigue life of high strength concrete.

Three sizes of deformed bars and two types of steel fibers with four different volume fractions were used to observe bond-slip and pull-out characteristics of high strength concrete. The results indicate that the maximum …

Anaerobic Biodegradation Of Trichloroethylene With The Addition Of Sugar Using Activated Carbon-Fluidized Beds, Suxan Huang

Dissertations

Anaerobic biodegradation of trichloroethylene (TCE) was carried out in a two-stage granular activated carbon fluidized bed bioreactor. The intermediate products were identified as: dichloroethylene (DCE), vinyl chloride (VC), 1,2-dichloroethane (DCA) and chloroethane (CA). Of the three geometric isomers of DCE, the trans-1,2 dichloroethylene (TDCE) was found to be the most predominant species, The production of DCA suggested a diverted reaction sequence from the conventional sequential reductive dechlorination pathway postulated in the past literature. CA was believed to be a product of VC and/or DCA. The co-substrate glucose was implicated for this reaction specificity. Based on our data and on other's …

Air Stripping Of Volatile Organic Contaminants Using Rotating Disc Contactor, Kai-Ping Hsueh

Dissertations

Previous studies have suggested that the transfer of VOCs to the atmosphere by air stripping may be a convenient and potentially cost-effective method to remove these compounds from the water. A Rotating Disk Contactor (RDC), similarly to other aeration devices, can provide intimate contact between the VOC-bearing water and air. It is believed that under carefully selected operating conditions, the RDC system are more competitive with packed tower than other aeration methods. The objectives of this study were to evaluate the feasibility of using the RDC to strip VOCs from the contaminated water and to develop a mathematical model to …

Permeability And Volume Change Characeristics Of Bentonite-Sand Mixes In A Contaminant Environment, Yuan-Hsun Wu

Dissertations

This research was conducted to study the characteristics of permeability and volume change of bentonite-sand mixes due to contaminants. The soil specimens consisted of clean sand, bentonite, and fly ash. Test liquids included seven diluted organic and inorganic chemicals and a landfill leachate.

Index tests included liquid limit, expansion, cracking, and sedimentation tests. Expansion tests proved to be the most useful for permeability evaluation in a contaminant environment.

The conventional consolidometer permeameter and flexible wall permeameter proved to be not completely satisfactory for testing soft bentonite mixes. A triple ring permeameter was developed to compensate for the limitations of these …

Environmental Impact Assessment For Water Resources Projects : Planning Procedure And Analytical Methods, Mahadesh C. Tumkur

Theses

This thesis presents a state of the art review of environmental impact assessment procedures utilised in the water resources projects which have evolved over the past two decades. The methodologies employed and some of their limitations which exist and are inherent in both the planning and assessment phases of analysis are identified. The above was supplemented by an investigation of the various views of professionals currently employing the above methodologies. The review effort summarizes the relevant information obtained from the literature which is rather dynamic because of the ever evolving nature of the field. One conclusion drawn from this study …

Competitive Bidding Strategy In The Construction Industry : A Game Theoretic Approach, Hongbin Chen

Theses

A game theoretic approach is applied to analyze competitive bidding in the construction industry because previous models do not consider the conflict of interest that exists among competitors. The game theoretic model improves corporate performance when compared to previous Bayesian analyses.

The game theoretic model is discussed in conjunction with construction contracting practice. Competitive bidding is formulated as a game theoretic model in which a contractor optimizes his bid price to maximize his utility or corporate performance. Using available historical data, order statistics are employed to access the distribution of estimated costs among bidders for a project. The winner's curse …

Adsorption And Desorption Of Chromium On Clayey Soils, Ker-Shu Tan

Theses

Chromium residue waste was produced during sixties in the chromium production process. It was used as construction fill. Problems associated with chromium waste sites include structure distress and surface and groundwater contamination.

The purpose of this study was to investigate the adsorption and desorption of chromium on soil. In order to achieve this purpose, experiments were conducted to study the effect of pH, type of chromium compound, and type of soil on adsorption and desorption.

Experiments were performed on kaolinite, bentonite and sand. In our study, it was found that sand had almost no adsorption for chromium. Kaolinite had less …

Surfactant Enhanced Scrubbing In An Ejector Venturi Scrubber Of Sulfur Dioxide From Air Exhaust Streams, Humberto Roman

Theses

The objective of this work was to determine the feasibility of applying the Surfactant Enhanced Scrubbing technique to the removal of sulfur dioxide using an ejector venturi scrubber.

Surfactants were chosen according to information from manufacturers. Those surfactants which offered good behavior in the presence of acidic solutions ( low pH ), and anti-corrosion characteristics were tested.

In the first phase, experiments were performed to determine the behavior of the foams in the ejector venturi scrubber. A foam destruction system was used when foaming conditions required it. In the second phase dynamic runs were performed to determine the removal efficiencies …