Sodium N-chloro-p-toluenesulfonamide (chloramine-T or CAT) is the prominent member of aromatic sulfonyl haloamines and has received considerable attention as a mild oxidant for several organic compounds. d-Biotin, a member of the B-vitamin family, is an essential nutrient in human nutrition as is commonly referred to as Vitamin H. Controlled oxidation of biotin to biotin sulfoxide forms a very important synthetic route in biochemical reactions. Optimum conditions have been developed for the oxidation of biotin to biotin sulfoxide. Literature survey has revealed that no attention has been paid towards the controlled oxidation of biotin to biotin sulfoxide by N-haloamines from the kinetic and mechanistic view points. This prompted us to undertake the title investigation. The kinetics of Os(VIII) catalyzed and uncatalyzed oxidation of biotin by CAT have been studied in NaOH medium at 303 K under identical experimental conditions. The stoichiometry (1:1) and the oxidation product (biotin sulfoxide) are the same for Os(VIII) catalyzed and uncatalyzed reactions. Biotin sulfoxide was confirmed by GC-MS analysis. In Os(VIII) catalyzed oxidation, the rate law is [Biotin] x /[NaOH] −y for uncatalyzed reaction, where x and y are less than unity. The reaction was subjected to changes in: (a) concentration of added reduction product of CAT, p-toluenesulfonamide, (b) ionic strength, (c) dielectric permittivity and (d) halide ions effect in both the cases. Proton inventory studies made in a mixture of H 2 O-D 2 O indicated the participation of OH − ion in the formation of transition state. The reaction fails to initiate polymerization of acrylonitrile. Activation parameters for the composite reaction were deduced from Arrhenius plots. In case of uncatalyzed reactions, the reaction constants involved in the proposed scheme were deduced. Under the identical set of experimental conditions, the kinetics of Os(VIII) catalyzed oxidation of biotin by CAT in alkaline medium has been compared with uncatalyzed reactions, revealing that the catalyzed reactions are eight fold faster than the uncatalyzed reactions. Hence, Os(VIII) acts as an efficient catalyst for the oxidation of biotin by CAT in alkaline medium. The catalytic constant (K C ) has been calculated at different temperatures and the values of activation parameters with respect to catalyst have been evaluated from the plots of log K C versus 1/T. Some spectroscopic evidence for the formation of 1:1 complex between oxidant and Os(VIII) has been obtained. CH 3 C 6 H 4 SO 2 NHCl has been postulated as the reactive oxidizing species in both the cases. The observed experimental results have been explained by plausible mechanisms and the related rate laws have been deduced for both catalyzed and uncatalyzed reactions.

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Laboratory-model studies were conducted to develop design guidelines for treatment of high-strength leachate (23,000 mg COD/L, 17,500 mg BOD/L, 8,000 mg TOC/L, 1,000 mg Fe/L and 80 mg Zn/L) generated from a landfill site that serves the metropolitan area of Halifax, Canada. The selected processes included two treatment systems, I and II. System I consisted of an anaerobic fixed film reactor (AFFR1), the effluent from which was further treated by an aerated lagoon and a settling lagoon in parallel. System II consisted of a second AFFR, but was not followed by any other treatment. The AFFR’s were upflow cylindrical tanks with plastic "Tellerette" rings which provided the fixed surface. This is the first known investigation which utilized the rings (patented by Pennwalt Corporation) that are manufactured as packing material in air pollution control devices. The pH-adjusted, settled and nutrient-supplemented leachate (pre-treatment step) was added to AFFR1, and AFFR2 to maintain organic loads of about 2 and 1.6 kg COD/day.m3, respectively. The two fixed film reactors were kept at 32 ± 1°C and the two lagoons at 20 ± 2°C. The 12-week study showed that system Ia, consisting of pre-treatment, AFFR1, and aerated lagoon, resulted in the best performance; system Ib, (pre-treatment, AFFR1 and settling lagoon) generated the second best effluent, followed by System II, which produced an inferior effluent. System la resulted in greater than 99% removal of COD, BOD, TOC, Fe and Zn. System Ib removed between 98% and 99% of COD and TOC and more than 99% of BOD, Fe and Zn. System II (pre-treatment and AFFR2), however, could remove between 97% and 98% of COD and TOC, and in excess of 99% of BOD, Fe and Zn. Similar data for the remaining 36 parameters are also included. Biogas generated by the two AFFR’s ranged from about 0.4 to 0.57 m3 per kg of COD destroyed. Comparisons have been made between the performance potentials, capital and operating costs and energy requirements, of the Systems Ia, Ib and II.

The following work is the CFD analysis of NACA 23024 airfoil. The analysis is carried out for a free stream Reynolds number of 3 million for which the wind tunnel results are available. The CFD analysis is carried out using Ansys Fluent Solver. The analysis is carried out using Spalart Allmaras turbulence model, K-omega SST turbulence model with flow transition capabilities, Standard K-Epsilon Turbulence model and K-omega SST turbulence model. The analysis results are then compared with the wind tunnel results and the performance of the turbulence models are discussed.