Theory of the photoelastic effect in ZnO,ZnS and CdS crystals

It has been a general opinion that the Clausius-Mossotti dielectric theory is not capable of explaining the observed photoelastic behaviour of partially ionic crystals.However in the present communication we show that by making account of the variation of polarizabilities under compressive stress within the framework of the Clausius-Mossotti theory it is possible to obtain a reasonable agreement with experimental data on the photoelastic behaviour of ZnO, ZnS and CdS crystals.     

Analysis of polarizabilities of alkali halides using Narayan-Ramaseshan repulsive potential

The repulsive potential in ionic crystals recently proposed by Narayan and Ramaseshan (NR) can be expressed as the sum of the contributions from the individual ions. In the present paper we show that using this repulsive potential it is possible to divide the polarizability arising from the relative displacement of ions into its ionic constituents. NR have also derived the ionic radii in alkali halides which we have used to estimate the electronic polarizabilities of ions with the help of polarizability-radius cube relation. The electronic polarizabilities of alkali and halogen ions thus evaluated show a good agreement with those deduced from the experimental refraction data.     

Quantitative Relationships Between Molecular Descriptors,Chromatographic Retention Behavior,and In Vitro Antituberculosis Activity of Phytol Derivatives

JPC – Journal of Planar Chromatography – Modern TLC - The lipophilic character of phytol derivatives has been studied using reverse-phase planar chromatographic procedures....     

Study of non-isothermal crystallization of amorphous Cu<Subscript>50</Subscript>Ti<Subscript>50</Subscript> alloy

The crystallization kinetics of amorphous Cu₅₀Ti₅₀ has been studied using differential scanning calorimetry (DSC) under non-isothermal conditions. The curves at different linear heating rates (2, 4, 8 and 16 K min^–1) show sharp crystallization peaks. The crystallization peak shifts to higher temperatures with increasing heating rate. The Kissingers method of analysis of the shift in the transformation peak is applied to evaluate the activation energy (E _c). The KJMA formalism, which is basically developed for isothermal experiments, is also used to obtain E _c and the Avrami parameter (n).The DSC data have been analysed in terms of kinetic parameters, viz. activation energy (E _c), Avrami exponent (n) and frequency factor K ₀ using three different theoretical models. It is observed that the activation energy values derived from KJMA approach and modified Kissinger equation agree fairly well with each other. The activation energy values obtained from normal Kissinger method, and Gao and Wang expression underestimate the activation energy.The financial support provided by All India Council for Technical Education (AICTE), New Delhi (Govt. of India) is gratefully acknowledged.     

Determination of chlorpyrifos 20% EC (Dursban 20 EC) in scented rose and its products

The method for determination of chlorpyrifos is validated and dissipation behaviour of residue in scented rose and percent transfer in different products is described. GC-electron-capture detection with a HP-1, 30 m x 0.53 mm, 3.0 microm capillary column and nitrogen at 1 ml/min was used in the study. Plant matrices studied were: leaves, flowers, soil, rose water, absolute and concrete. Detector response linearity and sensitivity, limit of detection and determination, percent recovery were determined based on area response (mm2) of the standard. Analytical field and laboratory samples (rose water by hydro-distillation of the flowers, concrete and absolute by hexane extraction and condensation) were analysed for evaluation of the method. Samples were extracted with acetone, partitioned with water, saturated sodium chloride solution and dichloromethane. The organic layer was rotary-evaporated to 2 ml for cleanup with silica-carbon column. The column was eluted with dichloromethane-toluene-acetone (10:2:2, v/v/v) and the derived solution was rotary-evaporated to 5 ml for end analysis. Matrix enhancement effect was observed for leaf and soil samples for which corrective approach was followed to compensate for overestimation of the residue. Limit of detection for chlorpyrifos standard was 0.05 mg/l with good linearity of detector response (R2 = 0.99). Percent recovery ranged from 78 to 117% in different plant matrices (fortification level 1, 4 and 8 mg/l). Dissipation behaviour showed that chlorpyrifos was below detection limit by the 12th day of application on the scented rose with half life of 3.40 days on leaves and 3.10 days on flowers at 0.1% dosage. Percent transfer studies showed that 5.71, 46.91 and 38.80% of the residue from flowers was transferred to rose water, concrete and absolute, respectively.     

Metal‐induced rearrangement of benzothiazoline ring: Synthesis and characterization of some new organoantimony(V) derivatives of N,O, and S atom containing schiff base ligands

Some new triphenylantimony(V) derivatives of Schiff bases having the composition have been synthesized by the equimolar reactions of Ph₃SbBr₂ with newly synthesized benzothiazoline ligands, (where R = C₆H₅(H₂L¹), 4‐BrC₆H₄(H₂L²), 4‐ClC₆H₄(H₂L³), 4‐CH₃‐OC₆H₄(H₂L⁴), 4‐CH₃C₆H₄(H₂L⁵)). The reaction proceeds with the rearrangement of benzothiazoline ring. All the derivatives have been characterized by elemental analyses, molecular weight measurements and their plausible structures have been proposed on the basis of IR and NMR (¹H and ¹³C) spectral studies. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:70–75, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20260     

Impact of information sharing and lead time on bullwhip effect and on-hand inventory

This work analyzes a two echelon (warehouse–retailer) serial supply chain to study the impact of information sharing (IS) and lead time on bullwhip effect and on-hand inventory. The customer demand at the retailer is assumed to be an autoregressive (AR(1)) process. Both the echelons use a minimum mean squared error (MMSE) model for forecasting lead time demand (LTD), and follow an adaptive base-stock inventory policy to determine their respective order quantities. For the cases of without IS and inter as well as intra echelon IS, expressions for the bullwhip effect and on-hand inventory for the warehouse are obtained, considering deterministic lead-time. The results are compared with the previous research work and an easy analysis of the various bullwhip effect expressions under different scenarios, is done to understand the impact of IS on the bullwhip effect phenomenon. It is shown that some part of bullwhip effect will always remain even after sharing both inter as well as intra echelon information. Further, with the help of a numerical example it is shown that the lead time reduction is more beneficial in comparison to the sharing of information in terms of reduction in the bullwhip effect phenomenon.