Engineering Commons^™

Adsorption Of Organic Compounds By Microbial Biomass, Ariamalar Selvakumar

Dissertations

The adsorption of hazardous organic compounds such as phenol, 2-chlorophenol, 2-nitrophenol, chlorobenzene, and ethylbenzene onto two types of inactive microbial biomass (activated sludge and nitrifying bacteria) was studied. The adsorption isotherms could be expressed by the Freundlich adsorption isotherm and were found to be nearly linear over the range of concentrations (50 - 200 mg/1) studied. Desorption studies showed that the adsorption process was partially reversible. Heat of sorption was estimated and indicate that the biosorption process involves a physical rather than a chemical mechanism. The adsorptive capacity of biomass is about two to three orders of magnitude less than …

Softening Response Of Concrete In Direct Tension, Teresa Cintora

Theses

Due to the increased attention in nonlinear fracture mechanics and numerical methods of cementitious material, it has become necessary to have a reliable investigation of the post-peak softening response of concrete under direct uniaxial loading. But due to the brittleness of the material previous researchers have encountered great difficulty in obtaining complete data regarding the load-deformation behavior. This study uses a strain-controlled testing method and therefore the post-peak curve can be more easily obtained. Based on these results a unique formula for the normalized load vs. deformation curve has been proposed to be applied in fracture analysis applications.

Sorptive And Geotechnical Characteristics Of Kaolinite, Chi-Yuan Shih

Theses

The sorption/desorption behavior of phenol and chlorobenzene as well as their influence on geotechnical characteristics of kaolinite were studied. The results reveal that the sorption process follows closely with the Freundlich adsorption isotherm whereas the sorption/desorption ratio depends upon the characteristics of organic compounds.

A series of geotechnical properties tests was also undertaken after achieving equilibrium at different concentrations of organic compounds. It was found that the parameters such as liquid limit, plastic limit, optimum moisture content, and dry density increase with an increasing-concentration of organic compounds.

The relationship between the geotechnical, properties and sorption behavior of soils provides the …

Study Of The Structure And Capacity Of Construction Industry In Pakistan, Tayyab A. Ansari

Theses

The construction industry is the second largest sector in Pakistan's economy after agriculture. It is a fragmented industry which includes very small and very large contracting groups. It includes professional groups such as architects, engineers, management personnel etc. Major part of this industry is dominated by material's suppliers, vendors etc.

In the light of the developments which have taken place particularly over the last ten years, the study has covered the capacity of the construction industry in terms of estimated output, availability of manpower, demand and production of building materials , financial problems, credit, quality of work, the role of …

A Hydrological Characterization Of A Zero-Order Basin In Volcanic Hillslope Terrain, Neil A. Mock

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hydrologists have displayed a renewed effort towards understanding the complexity of runoff generation and its association with basin structure. Basin structure is defined as the complex geomorphological, vegetation, and soil characteristics that make up and distinguish the physical nature of a drainage basin. Zero-order basins are an integral part of watershed structure because they furnish the capacity to store and transmit snowmelt and rainfall. By definition, zero-order basins are sub-basins which are depressions in the surf ace and shallow bedrock topography. This study involves a space time characterization of a zero-order basin in fractured media located in southwest Idaho.

The …

Behavior Of Reinforced Loess Specimens Under Triaxial Load, Mohammad Taghi Izadi

Masters Theses

"Effects of reinforcement on shear strength of a loessial (silty) soil arc studied. Unconsolidated undrained triaxial tests are performed on unreinforced and fabric reinforced soil specimens. Analyses of the test results showed that in general the shear strength of remolded loess specimens were improved substantially and increase in the shear strength was directly related to reinforcement spacing.

The mechanism of soil-reinforcement interaction and several existing analytical models are described. A modified analytical model based on enhanced confining theory is developed. This model can be used in assessing the effects of the reinforcement on shear strength of triaxial specimens. Comparison of …