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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.
1

Derivatives of trifluorovinylsulfur pentafluoride and F-(tert-butyl) hypochlorite

Canich, Jo Ann Marie 01 January 1984 (has links)
Trifluorovinylsulfur pentafluoride dimerizes to (SF5CFCF2)2 in the presence of cesium fluoride. Two derivatives of trifluorovinylsulfur pentafluoride, SF5CF(CF3)C(O)F and SF5CF(CF3)C(O)NH2, were used to prepare the new compounds, SF5CF(CF3)CO2H and SF5CF(CF3)CN, respectively. The first was prepared by reacting the SF5-acid fluoride with water, while the second involved the abstraction of water from the SF5-amide using P4O10. The attempted preparation of a bis-pentafluorosulfur ketone and a pentafluorosulfur containing acid anhydride were unsuccessful. Selected transition and post transition metal chlorides and elements undergo oxidative displacement and oxidative addition reactions with F-(tert-butyl) hypochlorite, (CF3)3COCl, to form new F-(tert-butoxides). Preliminary studies with selected aromatic systems were also carried out.
2

Adsorption Removal of Tertiary Butyl Alcohol from Wastewater by Zeolite

Butland, Tricia Dorothy 29 April 2008 (has links)
Tertiary butyl alcohol (TBA) is used as a fuel oxygenate and is the main breakdown component of methyl tert butyl ether (MTBE). As such, TBA is found in water systems through storage leaks and spills, presence of MTBE in the water, and as an impure byproduct of MTBE-blended fuels. It presents several health hazards and is a suspected carcinogen. Studies involving aquatic life, mice and rats indicate that TBA is a concern at low concentrations. Wastewater removal of tert butyl alcohol (TBA) has been limited to methodology used by MTBE or by anaerobic or aerobic methods. Neither set of techniques is applicable to TBA due to its long biological degradation period, its very specific conditions for anerobic or aerobic treatment, and its low Henry's law constant, low transformation rate, and its high mobility. The main goal of this project was to determine the adsorption capabilities of different zeolites for TBA. A comparison to previous work done with powdered zeolites and MTBE is shown in the following Chapters. Batch systems of TBA and several different zeolites were examined to determine the best zeolites for TBA adsorption. As shown in Chapter 3, the best zeolites for TBA adsorption over an equilibrium time of 48 hours were silicalite and HiSiv 3000 pellets. Using the two chosen zeolites, silicalite and HiSiv 3000, adsorption isotherms were created and compared against MTBE data using the same data. The final portion of this project included a continuous system consisting of a zeolite column and a steady flow rate of TBA. The zeolite columns consisted of sole silicalite, sole HiSiv 3000, and different proportions of the two zeolites in the same column. All column experiments were run at similar conditions with variation in the adsorbent bed lengths for easy comparison between the resulting breakthrough curves. At the 3-cm bed length, the zeolite columns outperformed the activated carbon column; however, there was no distinct difference between the zeolite columns. In the 6-cm bed length experiments, there were apparent differences between the two zeolite breakthrough curves. The 9-cm column did not differentiate between the zeolites.
3

Performance Study on the Treatment of MTBE-Borne Waste Gas by Activated Sludge Aeration and Biotrickling Filtering Processes

Su, Li-Chun 14 June 2005 (has links)
In this study, a laboratory-scale activated sludge reactor and a biotrickling filter were constructed to study the removal of methyl tert-butyl ether (MTBE) from air vented from contaminated sites. The activated sludge tank (0.4 m¡Ñ0.4 m cross-sectional area, 3.0 m height, and 480 L total volume) was made by acrylic resin. A mixed liquor suspended solids (MLSS) concentration of 2000-3000 mg/L was maintained in the experimental mixed liquor and the sludge was acclimated for 30 days under selected conditions of a Food to Microorganism Ratio (F/M) of 0.3 g BOD/(g MLSS¡Dday) and an influent gas MTBE concentration (C0) of 180 mg/Am3 (@27oC). Results on performance tests show that an average MTBE removal efficiency of 93.6% was obtained with the operation conditions of C0 of 610 mg/Am3 (@27oC), volumetric aeration rate of 0.063 m3/m3¡Dmin, MLSS of 2600 mg/L, and submerged liquid depth of 1.0 m. The biotrickling filter was made by combining two same type of acrylic resin columns (each 0.2 m inner diameter, 2.0 m height, and packed with 900 pieces of polypropylene Pall rings to a height of 1.35 m) in series for the test gas flow and in-parallel for the trickling liquid flow. Each test was operated for 8 hours to reach a steady state for a set of selected conditions (gas flow rate 0.050 m3/min and superficial gas velocity 0.027 m/s, trickling liquid flow rate 0.004 m3/min and pH: 6.8-7.2, and liquid/gas flow ratio: 80 L/m3). Results show that the MTBE removal efficiencies from the influent gas were 40%, 22% and 15%, respectively, with C0 of 50,100 and 230 mg/Am3 (@27oC).
4

The effect of YDL100c deficiency on the growth of Saccharomyces cerevisiae in the presence of t-BOOH

JUNG, CHAN 28 July 2006 (has links)
To study the role of YDL100c during the growth of Saccharomyces cerevisiae in the presence of oxidant, the wild type strain (WT) and YDL100c disrupted strain (KO) were grown at 30oC for 6 hr after adding 0.25 mM of tert-butyl hydroperoxide (t-BOOH). The cells of both strains were assayed for the expression of anti-oxidant system, trehalose accumulation, intracellular molecular oxidation level, membrane lipid peroxidation, and glutathione (GSH) content. The results show that growth of KO is slower than that of WT and the cause of growth delay is the cell death. The data also show that the molecular oxidation level is lower but the lipid peroxidation of membrane is higher in KO compared with WT in the presence of t-BOOH, indicating that ROS do cause the damage on membrane. Further, analysis of the expression of cellular defense-related genes show that expressions of GSH1, CTT1, TPS1, TSL1, and NTH1 in KO are lower than in WT, but expressions of SOD1, TRR1 and TRX1 have no difference, demonstrating that the deletion of YDL100c in S. cerevisiae affects the general and specific stress response when grown in the presence of t-BOOH. In general, the decrease in CTT1 expression is not consistent with the catalase activity assay, however, decreased expressions of GSH1 and genes involved in trehalose metabolism are consistent with the decreased GSH content and increased trehalose accumulation in KO compared with WT. Therefore, the cause of KO cell death in the presence of t-BOOH is most likely related to the decrease in cellular GSH level and trehalose accumulation.
5

Coordination Chemistry of a 5-tert-Butyl-2-[(2,6-diisopropylphenyl)aldimino]- pyrrolate Ligand

Yang, Chih-Wei 13 September 2002 (has links)
The Vilsmeier-Haack reaction of pyrrole with oxalyl chloride and N,N-dimethylformaldehyde followed by Friedel-Crafts alkylation with Me3CCl in the presence of AlCl3 afforded 5-tert-butylpyrrole-2- carbal- dehyde in high yields. Condensation reactions of 5-tert-butylpyrrole-2- carbaldehyde with 2,6-diisopropylaniline produced 5-tert-Butyl-2-2[(2,6- diisopropylphenyl)aldimino]pyrrole (HL). Protonolysis of MgnBu2 with HL yielded the bis(iminopyrrolate) complex MgL2 (1) as a colorless crystalline solid. In situ lithiation of HL followed by addition of one equivalent of ZrCl4 or AlCl3 led to the mono(iminopyrrolate) complexes ZrLCl4Li(OEt2)2 (2) and AlLCl2 (3) , respectively. Treatment of 3 with two equivalents of MeMgBr produced AlLMe2 (4). In addition to the spectroscopic data, all metal complexes were characterized by X-ray crystallography.
6

Adsorption removal of tertiary butyl alcohol from wastewater by zeolite

Butland, Tricia Dorothy. January 2008 (has links)
Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: zeolite adsorption, TBA, tert butyl alcohol, wastewater remediation. Includes bibliographical references (leaves 60-62 ).
7

Synthesis of Modular Pseudopeptide Ligand Systems for Modeling Enzyme Active Sites

Smart, Varrie Russell 24 August 2011 (has links)
No description available.
8

Dégradation d'un composé xénobiotique récalcitrant : métabolisme du méthyl tert-butyl éther (MTBE) par mycobacterium austroafricanum IFP 2012

François, Alan 28 November 2002 (has links) (PDF)
Afin d'obtenir le niveau requis d'indice d'octane et de limiter les rejets en monoxyde de carbone, les éthers carburants, principalement le méthyl tert-butyl éther (MTBE), sont incorporés dans les essences. A la suite de fuites, le MTBE est apparu comme un polluant majeur des nappes aquifères en raison de sa très faible biodégradabilité. L'objectif de ce travail a été d'étudier la dégradation du MTBE par Mycobacterium austroafricanum IFP 2012. La voie métabolique a été partiellement élucidée par l'identification de plusieurs intermédiaires (tert-butyl formiate (TBF), tert-butyl alcool (TBA), acide -hydroxyisobutyrique et acétone) et activités enzymatiques (MTBE/TBA mono-oxygénase non-hémique et inductible, TBF estérase, 2-propanol : NDMA oxydoréductase et une mono-oxygénase impliquée dans la dégradation de l'acétone). Le rôle du TBF et la nécessité de cobalt ont été proposés pour expliquer la faible biodégradation du MTBE ; le rôle de la liaison méthoxy semblant limité.
9

THERMODYNAMIC AND SPECTROSCOPIC ANALYSIS OF TERTBUTYL ALCOHOL HYDRATE: APPLICATION FOR THE METHANE GAS STORAGE AND TRANSPORTATION

Park, Youngjune, Cha, Minjun, Shin, Woongchul, Cha, Jong-Ho, Lee, Huen, Ripmeester, John A. 07 1900 (has links)
Recently, clathrate hydrate has attracted much attention because of its energy gas enclathration phenomenon. Since energy gas such as methane, ethane, and hydrogen could be stored in solid hydrate form, clathrate hydrate research has been considerably focused on energy gas storage and transportation medium. Especially, methane hydrate, which is crystalline compound that are formed by physical interaction between water and relatively small sized guest molecules, can contain about as much as 180 volumes of gas at standard pressure and temperature condition. To utilize gas hydrate as energy storage and transportation medium, two important key features: storage capacity and storage condition must be considered. Herein, we report the inclusion phenomena of methane occurred on tert-butyl alcohol hydrate through thermodynamic measurement and spectroscopic analysis by using powder X-ray diffractometer, and 13C solidstate NMR. From spectroscopic analysis, we found the formation of sII type (cubic, Fd3m) clathrate hydrate by introducing methane gas into tert-butyl alcohol hydrate whereas tert-butyl alcohol hydrate alone does not form clathrate hydrate structure. Under equilibrium condition, pressure-lowering effect of methane + tert-butyl alcohol double hydrate was also observed. The present results give us several key features for better understanding of inclusion phenomena occurring in the complex hydrate systems and further developing methane or other gas storage and transportation technique.
10

Molecular simulation of the adsorption of organics from water

Yazaydin, Ahmet Ozgur. January 2007 (has links)
Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: Water; Adsorption; Molecular simulation; Nanoporous materials. Includes bibliographical references (p. 117-119).

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