http://nopr.niscair.res.in/handle/123456789/851 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/876 Title: Prediction of minimum slugging velocity, bubbling bed index and range of bubbling fluidization in cylindrical and non-cylindrical gas-solid fluidized beds <br/> <br/>Authors: Singh, R K; Roy, G K <br/> <br/>Abstract: A bubbling fluidization regime exists between the minimum bubbling velocity and the minimum slugging velocity. Experimental investigations have been carried out for the determination of the minimum slugging velocity and the range of bubbling fluidization for non-spherical particles in cylindrical and non-cylindrical beds. In the present paper, correlations have been developed for the prediction of minimum slugging velocity for gas-solid fluidization in cylindrical and non-cylindrical (viz. semi-cylindrical, hexagonal and square) beds for non-spherical particles fluidized by air at ambient conditions. The bed materials used have varied diameter (324 to 925 micron) and density (1500 to 4800 kg/m³). Experimental values of the minimum slugging velocity have been compared with the values calculated by the developed equations and also with the values calculated by Geldart’s equation. A fairly good agreement has been obtained between the calculated and the experimental values. Based on the experimental data, it is concluded that, under similar operating conditions minimum slugging velocity and minimum bubbling velocity are maximum in case of a semi-cylindrical conduit and minimum in case of a square one. It is further observed that the range of bubbling fluidization is maximum in case of a semi-cylindrical bed for the identical operating conditions. <br/> <br/>Page(s): 85-89 Sat, 29 Dec 2007 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/875 Title: Electrodeposition of nickel from dimethyl sulphoxide bath: Effect of nucleoside <br/> <br/>Authors: Gupta, Ashutosh K; Srivastava, H K; Singh, Jyotsna; Srivastava, Priyanka; Kashyap, Rahul <br/> <br/>Abstract: Dimethylsulphoxide (DMSO) may act as a potent medium for electrodeposition of Ni in presence of nucleosides. Totally bright electroplate may result from NiAc+NiSO₄+NiSMT/DMSO bath in presence of trace amount of nucleoside (ribocytine/deoxycitidine). Too many coordinating centers of nucleoside facilitate the release of Ni from [Ni(DMSO)₆]³⁺ complex in the vicinity of catholite causing outwardly growth more dominant than lateral growth, resulting in bright, adherent, Ni electrodeposite. <br/> <br/>Page(s): 82-84 Sat, 29 Dec 2007 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/873 Title: Solvent extraction and spectrophotometric determination of copper(II) with 2-hydroxy-5-methyl acetophenoneisonicotinoylhydrazone (HMAINH) <br/> <br/>Authors: Aswar, A S; Joshi, M D <br/> <br/>Abstract: A new simple and sensitive extractive spectrophoto- metric method for the determination of copper (II) with reagent 2-hydroxy-5-methylacetophenoneisonicotinoylhydrazone (HMAINH) has been presented in this paper. The reagent HMAINH reacts with Cu (II) to give a yellow coloured complex, which can be quantitatively extracted into chloroform at 3.4 pH. The complex shows absorption maximum at 440 nm, where absorption due to reagent is negligible. The Beer’s law is obeyed in the concentration range of 0.5–4.0 ppm of Cu (II). The molar absorpitivity and Sandell’s sensitivity of extracted species are 9.340 x 10³ dm³ mol⁻¹cm⁻¹and 6.8 ηg cm⁻² respectively. The stoichiometry of the extracted species is found to be 1:1. The standard deviation is 0.0566. The effect of various diverse ions on the estimation of Cu (II) has been studied. <br/> <br/>Page(s): 79-81 Sat, 29 Dec 2007 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/872 Title: Esterification of carboxylic acids by acid activated Kaolinite clay <br/> <br/>Authors: Konwar, Dilip; Gogoi, Pradip K; Gogoi, Pranjal; Borah, Geetika; Baruah, Ruby; Hazarika, Neelakshi; Borgohain, Rituraj <br/> <br/>Abstract: Esterification of carboxylic acid was carried out by using acid activated kaolinite clay. This heterogeneous catalyst, activated kaolinite clay has been found to be a mild solid catalyst for the esterification of carboxylic acid in good yields. The catalyst is recoverable and can be recycled after activation. <br/> <br/>Page(s): 75-78 Sat, 29 Dec 2007 22:58:59 GMT