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When irradiated alkali halides are heated they give rise to thermoluminescence (TL) because of thermal annealing of coLor centers with suitable radiative recombination at the emission centers. TL occurring above RT in the case of highly pure (background divalent cation impurity not greater than 1 ppm) alkali halide crystals has been correlated with thermal annealing of the first and second stage of F centers /1, 2/. The presence of impurities and plastic de-formation is known to introduce additional TL peaks. In the case of Ca-doped NaCl T L peaks occurring above RT have been correlated with thermal annealing of F center elctrons trapped in different local environments /3/. Keeping in mind this correlation we have attempted in the present investigation to study the effect of post-irradiation deformation in the same system to understand the interaction of F centers produced during irradiation with those of other lattice defects produced during plastic deformation. It is to be noted that the possible effects of pre-irradiation and post-irradiation deformation a r e not the same, the difference being rightly pointed out by De Werd et al. /4/. The relationship between pre-irradiation deformation and TL has been studied in some detail, reference to which can be found in the previous studies /4, 5/. However, no serious attempts have been made to understand the effect of post-irradiation deformation on T L of alkali halides though TL in these systems has been studied in great detail.All the samples used were in fine powder form. In all cases before irradiation the sample was annealed at about 400 OC for about 30 min and cooled slowly to RT (~2 5 OC). The sample was irradiated by X-rays obtained from a Cu target of a tube operated at 30 kV and 5 mA. The TL curves were recorded under identical conditions, the sample being heated at uniform rate of (28 : 1) b & a l 7950B3, India.

This study describes the effect of anionic and cationic micelles on nucleophilic addition reaction of rosaniline hydrochloride (RH) with hydroxide under pseudo-first order condition. Strong inhibitory effect is observed due to SDS micelle, whereas CTAB catalysed the reaction. This is explained on the basis of electrostatic and hydrophobic interactions which are simultaneously operating in the reaction system. The kinetic data obtained is quantitatively analysed by applying the positive cooperativity model of enzyme catalysis. Binding constants and influence of counterions on the reaction have also been investigated.

Silver nanoparticles (AgNPs) were prepared by employing green chemicals such as gallic acid as reductant and starch as a stabilizer. The maximum absorption peak at 443 nm of the synthesized nanoparticles was observed in UV-visible spectrum. The existence of the fcc structure of silver nanocrystal with intense diffraction peak along (111) plane with a crystallite size of 9.32 ± 1.31 nm was evidenced from XRD studies. Quasi-spherical AgNPs of average diameter 48.42 ± 14 nm, hexagonal AgNPs with mean edge length 31.75 ± 7.29 nm and triangular AgNPs of mean edge length 48.55 ± 11.37 nm were confirmed from the TEM images. FTIR analysis verified that the synthesized AgNPs were stabilized by starch. The AgNPs was used as a catalyst in the alkaline hydrolysis of crystal violet dye. A 2.41 × 10-2 min-1 and 4.49 × 10-2 min-1 were degradation rate constants of crystal violet in the absence and presence of silver nanoparticles, respectively. The results clearly highlighted that the green synthesized silver nanoparticles can be used as catalyst in the degradation of toxic dyes in industrial effluents and environment.