http://nopr.niscair.res.in/handle/123456789/11991 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/12002 Title: Inhibition efficiency of two bipyrazole derivatives on steel corrosion in hydrochloric acid media <br/> <br/>Authors: Tebbji, K; Aouniti, A; Attayibat, A; Hammouti, B; Oudda, H; Benkaddour, M; Radi, S; Nahle, A <br/> <br/>Abstract: The inhibitor effect of two isomers namely 2-(1',5,5'-trimethyl-1H,1'H-3,3'-bipyrazol-1-yl)ethanol (1-TBE) and 2-(1',5,5'-trimethyl-1H,2'H-3,3'-bipyrazol-2-yl)ethanol (2-TBE) on the corrosion of mild steel in 1.0 M hydrochloric acid has been investigated at 308 K using weight loss measurements and electrochemical techniques (impedance spectroscopy and polarisation curves). Inhibition efficiency is dependent upon the pyrazole structure, with 1-TBE serving as a better inhibitor than 2-TBE and its inhibition efficiency increases with the increase of concentration of inhibitor to attain 93% in the presence of 10^-3M. Polarisation curves indicate that 1-TBE and 2-TBE act essentially as cathodic inhibitors. Efficiency (<i style="">E</i>) percent values obtained by various methods are reasonably good in agreement. EIS measurements show an increase of the transfer resistance with the inhibitor concentration. The temperature effect on the corrosion behaviour of steel in 1.0 M HCl without and with the inhibitor at 10^-3M is studied in the temperature range 308-333 K, Some thermodynamic parameters such as adsorption heat (<img src='/image/spc_char/delta.gif' border=0><i style="">H</i>°), adsorption entropy (<img src='/image/spc_char/delta.gif' border=0><i style="">S</i>°) and adsorption free energy (<img src='/image/spc_char/delta.gif' border=0><i style="">G</i>°) have been calculated by employing thermodynamic equations. Kinetic parameters such as apparent activation energy and pre-exponential factor have also been calculated. Adsorption of 1-TBE on the mild steel surface in 1.0 M HCl follows the Langmuir isotherm model. <br/> <br/>Page(s): 244-253 Thu, 28 Apr 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/12001 Title: Homogeneous grafting of PMMA onto cellulose in presence of Ce⁴⁺ as initiator <br/> <br/>Authors: Tosh, B; Routray, C R <br/> <br/>Abstract: Poly (methyl methacrylate) (PMMA) is successfully grafted onto cellulose in homogeneous medium in N,N-dimethyl acetamide/LiCl solvent system. The method is based upon ring opening reaction of cellulose with Ce⁴⁺ ion. Ceric ammonium nitrate (CAN) forms free radical on cellulose back bone in presence of DMSO via ring opening mechanism and PMMA is grafted through homogeneous breaking of the acrylic double bond. Methylene blue was used as an inhibitor to check the formation of homopolymer. The graft yield and grafting efficiency was studied by varying reaction time, temperature, and monomer concentration. The products are characterized by FTIR and ¹H-NMR analysis and a possible reaction mechanism is deduced. Thermal degradation of the grafted products is also studied by thermo-gravimetric analysis (TG). <br/> <br/>Page(s): 234-243 Thu, 28 Apr 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/12000 Title: Estimation of dynamic viscosities of vegetable oils using artificial neural networks <br/> <br/>Authors: Aksoy, Fatih; Yabanova, İsmail; Bayrakçeken, Hüseyin <br/> <br/>Abstract: In this study, viscosities of raw sunflower and corn oils are measured at 1°C intervals between 0-100°C. Experimental results are fitted to six equations that are used in viscosity estimation and the correlation coefficients are determined. The best correlation coefficient is obtained using In(<img src='/image/spc_char/micro.gif' border=0>)=a+b/(T+c) equation with 0.99972 and 0.99974 for sunflower and corn oil, respectively. In addition to this, viscosity values are obtained using artificial neural networks and the results are compared to the equation leading to the best correlation coefficient. Using artificial neural networks, the correlation coefficients are obtained as 0.999907 and 0.999925 for raw sunflower and corn oil respectively. <br/> <br/>Page(s): 227-233 Thu, 28 Apr 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/11999 Title: Removal of basic dye from aqueous solution by biosorption on to sewage sludge <br/> <br/>Authors: Dave, Pragnesh N; Kaur, Satindar; Khosla, Ekta <br/> <br/>Abstract: Sorption experiments are carried out using sewage sludge for the removal of basic dye basic red-12 from aqueous solution. Effects of process parameters such as initial pH, adsorbent dosage, initial dye concentration, contact time and effect of temperature are investigated. The biosorbent is characterized by FTIR, SEM and XRD. The adsorption of dye is pH dependent. The rate of sorption increases with increase in temperature, and the process is found to be endothermic. Equilibrium is established in 120 min. The pseudo first-order equation, pseudo second-order equation and intraparticle diffusion models are tested. The results showed that the process followed pseudo first order equation very well and intraparicle diffusion plays an important role in the sorption process. The Langmuir and Freundlich equations are applied to the data related to adsorption isotherm and the observed maximum adsorption capacity was found to be 295.85 mg/g. Thermodynamic parameters; <img src='/image/spc_char/delta.gif' border=0><i style="">H</i>°, <img src='/image/spc_char/delta.gif' border=0><i style="">G</i>°and <img src='/image/spc_char/delta.gif' border=0><i style="">S</i>° are also evaluated. Column experiments are also carried out to evaluate the bulk removal of color from effluents. The effects of inlet concentration and bed height are evaluated. <br/> <br/>Page(s): 220-226 Thu, 28 Apr 2011 22:58:59 GMT