Engineering Commons^™

A Study On Radical Scavenging And Magnetic Resonance Imaging Characteristics Of Stable Radical Nitroxides, Shiey-Shiun Horng

Dissertations

Several nitroxides have been prepared for study of their image enhancement capability. These nitroxides contain different nitroxyl moieties within one molecule. On MRI examination for the nitroxides prepared, TEMPO and HPTPO are better due to their better water solubility, even though some of the others have more nitroxyl centers available. The intensity response is linear with respect to concentration in the range studied in most of the cases except for HPTPO, whose intensity finally reaches maximum when its concentration is higher than 10 mM.

Three sources of biomass, namely, liver microsomes, whole-cell yeast and a bacterial activated sludge consortium, have …

Removal Of Volatile Organic Compounds (Voc's) Acetone And Ethyl Alcohol Emitted In The Manufacture Of A Multi-Base Propellant, Yih-Leu Liu

Theses

The Production Base Modernization Activity located at Picatinny Arsenal, initiated this study for the removal of the low concentrations of VOC's, acetone and ethyl alcohol emitted from the mixer operation and the forced air dry unit in the manufacture of a multi -base propellant. Air pollution requirements necessitate 85 % removal of the VOC's prior to discharge of the vent gases into the atmosphere. Because of the availability of sulfuric acid, it is proposed to use 70 percent or stronger acid as the absorbing agent in a recirculating acid absorption tower.

Vapor - Liquid Equilibrium ( VLE ) data were …

Mineralization Of 2-Chlorophenol Using A Hollow Fiber Ultrafiltration System In Combination With A Reactor Containing An Immobilized White Rot Fungus, Sheau-Ming Tung

Theses

Phanerochaete chrysosporium, a white rot fungus was immobilized on a packed-bed reactor, and was used to mineralize an aqueous stream contaminated with 50 ppm of 2-chlorophenol. Hollow fiber ultrafiltration membranes (for 5,000 daltons and 10,000 daltons molecular weight cut-oft) were utilized to retain the extracellular enzyme resulting from the immobilized fungus in a recirculation loop outside of the reactor.

It was found here that the concentration of proteins (roughly proportional to the extracellular enzyme releasd by the fungus) does not correlate with the rate of degradation of 2-chlorophenol in the system. The protein was concentrated 1.5 fold in the recycle …

Kinetic Studies Of Photo-Initiated Oxidation Of Toxic Organic Pollutants Including The Formation And The Destruction Of Intermediates, Yuan-Shen Li

Dissertations

The photo-initiated oxidation process, using hydrogen peroxide or ozone under ultraviolet radiation, has been proven to be an effective treatment method for toxic organic pollutants in wastewater. Most of the recent kinetic studies of the process were concentrated on the breakdown mechanisms of the pollutant itself. The formation and the destruction of intermediates were seldom investigated. Also the mechanisms and their reaction rate constants of free radical formation and destruction in the O₃/UV or H₂O₂/UV reactor were seldom studied.

The objective of this research is to study the kinetics of photo-initiated oxidation of toxic …

Thermal Desorption And Decomposition Of Hazardous Organic Compound I: Mass Transfer Of Benzene And Chlorobenzene In Soil Matrices Ii: Oxidation And Pyrolysis Of 1,1,1-Trichloroethane In Methane/Oxygen/Argon, Yo-Ping Wu

Dissertations

I: Mass Transfer of Benzene and Chlorobenzene in Soil Matrices

Experimental measurements on several apparatus were used in conjunction with chromatographic theory to study the thermal adsorption and desorption of organic vapors on soil with different particle sizes for analysis mass transfer parameters and heat of adsorption. Benzene (C₆H₆) and chlorobenzene (C₆H₅Cl) were tested on soil with 0.55, 0.46, 0.36, and 0.225 mm average particle sizes. Sample injection volumes for organic compounds were studied to ensure linearity of gas chromatography. Equilibrium constants were strongly dependent on temperature but not on particle size. …

Pure Strong Competition For Two Microbial Populations In A Chemostat, Efthimios Ioannis Banias

Theses

The dynamics of pure, strong, double competition between two microbial populations in an ideal chemostat have been investigated by using mathematical and numerical analysis. The two nutrients competed for have been assumed to be complementary for both competitors. Inter active models have been used for the specific growth rates. Two cases have been considered; one in which neither of the two substrates exerts inhibitory effects on the growth of either one of the competing populations, and one in which the growth of one population is inhibited by only one of the two substrates. The primary focus of this investigation was …

Evaluating The Homogeneity Of Solidification/Stabilization Treated Waste Soils By Chemical Analysis Method, Mei Liu

Theses

Solidification/Stabilization technology has been widely used for waste treatment, especially for heavy metals, non-volatile wastes, radioactive wastes and soils. Homogeneity is a very important criterion for this kind of technology.

This study focuses on the development of a method to evaluate the homogeneity of S/S treated soil. A chemical analysis method, atomic absorbance, is employed to evaluate the distribution of S/S reagent in a soil-cement mixture and thus the uniformity of the soil-cement mixture. Also, a fluorescent tracer method is discussed in this study, which can be used to estimate the homogeneity of the soil-cement surface. The fluorescent tracer method …

Inability Of Phanerochaete Chrysosporium To Degrade Polychlorinated Biphenyls In Sand, Pankaj Pankaj

Theses

The white rot fungus Phanerochaete chrysosporium has been previously found to successfully degrade a wide spectrum of chlorinated aromatic hydrocarbons (some of them in soil or sand matrices). In this research, it was tested if the fungus could also degrade a very recalcitrant class of pollutant, i.e. Polychlorinated Biphenyls (PCBs) in sand at a concentration of 100 ppm (w/w PCB to sand). For this purpose, a number of experiments were performed, in which several operating parameters, such as nutrient concentrations (nitrogen and glucose), amount of initial biomass, aeration, and degree of chlorination of the PCBs were varied. The results obtained …

Biodegradation Of Phenol And Benzoic Acid In Batch And Sequencing Batch Reactors, Stephane Reynaud

Theses

A pure culture of Pseudomonas aeruginosa ( ATCC 10145 ) was used for the biodegradation of phenol and benzoic acid. Two sets of small scale (shaker flask) experiments were originally performed: in the first set, phenol was the only carbon source present while in the second, benzoic acid was the sole carbon source. These experiments revealed the kinetics of benzoic acid degradation (they were found to be described by a Monod, non-inhibitory model), as well as of phenol biodegradation (they were found to be described by Andrews'inhibitory model) by Pseudomonas aeruginosa.

The kinetic expressions from the small scale experiments …