http://nopr.niscair.res.in/handle/123456789/802 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/2234 Title: Viscosities of binary liquid mixtures of some n-alkoxypropanols with n-alkanols at 298.15 K <br/> <br/>Authors: Pal, Amalendu; Gaba, Rekha <br/> <br/>Abstract: The viscosities (η) in binary liquid mixtures of (n-alkoxypropanols + methanol, ethanol, or I-propanol) have been measured as a function of composition using an Ubbelohde viscometer at 298.15 K and atmospheric pressure over the full range of composition. The n-alkoxypropanols are propylene glycol monomethyl ether (l-methoxy-2-propanol). CH₃OCH₂CH₂CH₂OH, propylene glycol monoethyl ether (l-ethoxy-2-propanol), C₂H₅OCH₂CH₂CH₂OH, propylene glycol monopropyl ether (l-propoxy-2-propanol), C₃H₇OCH₂CH₂CH₂OH, propylene glycol monobutyl ether (l-butoxy-2- propanol), C₄H₉OCH₂CH₂CH₂OH propylene glycol rert-butyl ether (l-rert-butoxy-2-propanol), CH₃CHOHCH₃0C(C₄H₉)₃. The η values for each of the mixture studied are positive over the whole mole fraction range. For all the cases, except propylene glycol rert-butyl ether, η increases in a positive direction with increase in chain length of n-alkoxypropanols. The values of Δη, which refers to the deviation of the experimental values of the dynamic viscosities of the mixtures from the mole fraction mixture law values, are found to be positive for all the mixtures. Further, the excess free energies of activation (ΔG*E) for viscous flow have been calculated from the experimental data. The results for η, Δη, and ΔG*E are discussed in terms of interactions between the components of the mixtures. Equations such as Heric's, Auslaender's, and MeAllister's four-body interaction model have been used to correlate the kinematic viscosities, <br/> <br/>Page(s): 1763-1771 http://nopr.niscair.res.in/handle/123456789/2206 Title: Restriction of pesticidal movement in contaminated soil and water <br/> <br/>Authors: Bhardwaj, Deepesh; Sharma, Pankaj; Tomar, Radha <br/> <br/>Abstract: Studies on restriction of pesticidal movement in contaminated soil and water are reported here. Sorption isotherms could be well described by the Freundlich equation form for all the three materials. Sorption of malathion on SAS-I and SAS-II has been found to be higher than that on SAS-III whereas desorption is less in case of SAS-III. Thermodynamic parameters for sorption have also been calculated to predict the mechanism of sorption. The thermodynamic studies suggest exothermic and physicochemical nature of sorption process. The FTIR analysis and thermodynamic studies exhibit the possibility of hydrogen bonding between the substrate and the pesticide molecule. It has been found that varying the sorptive properties of synthetic aluminosilicates results in immobilization of pesticides in a contaminated soil and protection of soil and water by using the aluminosilicates as pesticide carrier in slow release formulations. <br/> <br/>Page(s): 1796-1800 http://nopr.niscair.res.in/handle/123456789/2205 Title: Determination of Eu(III) based on fluorescence and cofluorescence enhancement of Eu(III)-Tb(III)-tetracycline-citrate system <br/> <br/>Authors: Wang, Xiaoli; Zhao, Huichun; Jin, Linpei <br/> <br/>Abstract: A new sensitized cofluorescence system has been developed for the determination of Eu(III) based on its complex formation with tetracycline (TC) in the presence of citrate and Tb(III). Eu(III) forms complex with tetracycline in alkaline condition which emits intrinsic fluorescence of Eu(III) when excited. The fluorescence intensity of Eu(III)TC is enhanced about 5 times when citrate and Tb(III) are introduced. The factors that influence the fluorescence intensity of the system have been studied in detail. Under optimum conditions, the relative fluorescence intensity is linear in over the range 6.0×10⁻⁹ to 4.0×10⁻⁶ M of Eu(III). The detection limit has been found to be 1.4×10⁻⁹ M of Eu(III). The method has been used for the determination of Eu in two rare earth samples with relative error 4.5% and -1.8%, and RSD 2.6% and 2.1%, respectively. <br/> <br/>Page(s): 1801-1804 http://nopr.niscair.res.in/handle/123456789/2203 Title: Kinetics and mechanism of oxidation of chalcones by trichloroisocyanuric acid [TCICA] in HOAc-HClO₄ medium <br/> <br/>Authors: Kumar, J Anil; Sondu, S <br/> <br/>Abstract: The kinetics and mechanism of oxidation of chalcone and some substituted chalcones by trichloroisocyanuric acid (TCICA) has been investigated at 313 K in HOAc-HClO₄ medium. The reaction has been found to be first order each in [TCICA] and [Chalcone] and fractional order in [H⁺]. There is no kinetic or spectral evidence for the formation of complex between TCICA and Chalcone. The rate increases with increase in percentage of acetic acid and [Cl⁻]. The products of oxidation have been identified as phenyl acetaldehyde and benzoic acid. The reactive species of oxidant have been established as HOCl and H₂OCl⁺. The rate increases with electron releasing groups in the benzaldehyde moety and vice versa with a Hammett’s ρ value of –0.45. A suitable mechanism involving the chalcone molecule and the reactive species of TCICA in the rate determining step has also been proposed. <br/> <br/>Page(s): 1792-1795