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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
361

Kinetic and mass transfer studies of ozone degradation of organics in liquid/gas-ozone and liquid/solid-ozone systems.

Grima, N.M.M. January 2009 (has links)
This work was concerned with the determination of mass transfer and kinetic parameters of ozone reactions with four organic compounds from different families, namely reactive dye RO16, triclocarban, naphthalene and methanol. In order to understand the mechanisms of ozone reactions with the organic pollutants, a radical scavenger (t-butanol) was used and the pH was varied from 2 to 9. Ozone solubility (CAL*) is an important parameter that affects both mass transfer rates and chemical reaction kinetics. In order to determine accurate values of the CAL* in the current work, a set of experiments were devised and a correlation between CAL* and the gas phase ozone concentration of the form CAL*(mol/L) = 0.0456 CO3 (g/m3 NTP) was obtained at 20°C. This work has also revealed that t-butanol did not only inhibit hydroxyl radical reactions but also increased mass transfer due to it increasing the specific surface area (aL). Values of the aL were determined to be 2.7 and 3.5 m2/m3 in the absence and presence of t-butanol respectively. It was noticed that the volumetric mass transfer coefficient (kLa) has increased following the addition of t-butanol. Ozone decomposition was studied at pH values of 2 to 9 in a 500 mL reactor initially saturated with ozone. Ozone decomposition was found to follow a second order reaction at pH values less than 7 whilst it was first order at pH 9. When the t-butanol was added, the decomposition of ozone progressed at a lower reaction order of 1.5 for pH values less than 7 and at the same order without t-butanol at pH 9. Ozone decomposition was found significant at high pHs due to high hydroxide ion concentration, which promotes ozone decomposition at high pHs. The reaction rate constant (k) of RO16 ozonation in the absence of t-butanol was determined. The result suggests that RO16 degradation occurs solely by molecular ozone and indirect reactions by radicals are insignificant. The chemical reaction of triclocarban with ozone was found to follow second order reaction kinetics. The degradation of naphthalene using the liquid/gas-ozone (LGO) system was studied. This result showed that hydroxyl radicals seemed to have limited effect on naphthalene degradation which was also observed when a radical scavenger (t-butanol) was used. Reaction rate constants were calculated and were found around 100 times higher than values reported in the literature due to differences in experimental conditions. From the results of the experimental investigation on the degradation of methanol by ozone it was found that the rate constant (k) of the degradation reaction increased at pH 9. The reaction stoichiometry was found to have a value of 1 mol/mol. The two steps of the liquid/solid-ozone (LSO) system were studied on beds of silica gel and a zeolitic material (D915) and the ozone adsorption process was modeled and found that particle rate controls ozone adsorption step but liquid rate controls the water treatment step. Ozone desorption with pure deionised water was studied. The water flow rate was found to accelerate the desorption rates but pH was found to decrease the desorption rates. In contrast, the effect of pH was insignificant in the presence of t-butanol. Determination of the adsorption isotherms for RO16, naphthalene and methanol revealed that RO16 did not exhibit adsorption on silica gel, but both naphthalene and methanol showed adsorption on D915 described by Langmuir model. / Education Service Department of the Libyan Government
362

NUMERICAL AND EXPERIMENTAL INVESTIGATION OF HEAT AND MASS TRANSFER IN ROTATING SYSTEMS

Boonpongmanee, Thaveesak 06 April 2005 (has links)
No description available.
363

Development of a Novel Air-to-Liquid Mass Transfer Mechanism

Lunka, Alex A. January 2014 (has links)
No description available.
364

Design, Development and Validation of UC Film Cooling Research Facility

Kandampalayam Kandasamy Palaniappan, Mouleeswaran January 2017 (has links)
No description available.
365

MASS TRANSFER ENHANCEMENT BY CORONA DISCHARGE AND MERCURY CAPTURE BY <i>IN-SITU</i> AEROSOL FORMATION

LEE, JOO-YOUP January 2002 (has links)
No description available.
366

MASS TRANSFER IN DENSE GAS EXTRACTION USING A HOLLOW FIBER MEMBRANE CONTACTOR

GABELMAN, ALAN January 2003 (has links)
No description available.
367

EFFECTS OF MASS-TRANSFER AND KINETIC PARAMETERS ON <i>BURKHOLDERIA CEPACIA</i>LIPASE IMMOBILIZED IN ORDERED MESOPOROUS SBA-15 HOSTS IN A PACKED-BED REACTOR

JALADI, HEMACHAND 02 October 2006 (has links)
No description available.
368

Computational Modeling of Heat and Mass Transfer in Planar SOFC: Effects of Volatile Species/Oxidant Mass Flow Rate and Electrochemical Reaction Rate

VENKATA, PADMA PRIYA 22 April 2008 (has links)
No description available.
369

CO2 Separation from Coal-Fired Power Plants by Regenerable Mg(OH)2 Solutions

Cheng, Lei 16 September 2013 (has links)
No description available.
370

Dependence of Film Cooling Effectiveness on 3D Printed Cooling Holes

Aghasi, Paul P. 06 June 2016 (has links)
No description available.

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