Colorimetric Estimation of Allyl Isothiocyanate Content in Mustard and Rapeseed Oils

A colorimetric method based on the colour reaction between allyl thiourea and potassium ferricyanide solution in dilute acetic acid has been developed for the determination of allyl isothiocyanate content in mustard and rapeseed oils. The method measures the optical density of the colour complex at 600 nm and it works in the range 2.5 to 7.5 μg of allyl isothiocyanate per ml of the colour solution. Mustard and rape oil samples analysed contain 0.40 to 0.6% of allyl isothiocyanate, with standard deviation of 0.002 to 0.016. The method takes around 3 hours and permits a number of sample analysis at a time.     

A thermodynamic method based upon the theory of regular solutions for selection of solvents and process conditions for aromatics extraction

Selectivity and distribution coefficients are two important parameters required for selection of solvents and process conditions for efficient separation of aromatics from a multi-component hydrocarbon feedstock. A simple thermodynamic method is presented in this paper for the prediction of these parameters from a knowledge of physical properties of the pure components, such as vapour pressure, molar volume and critical temperature. The activity coefficients were calculated using the solubility parameter theory extended to multi-component mixtures of polar and nonpolar components. The compositions of the extract and raffinate phases were computed using an iterative search technique for simultaneous solution of the thermodynamic criterion equations and the material balance equations for each component. For testing the validity of this method, the predicted values of the selectivity at infinite dilution and the equilibrium phase compositions were compared with the corresponding experimental values from the literature and the agreement is found to be highly satisfactory.     

Flow of materials in rotary kilns used for sponge iron manufacture: Part II. Effect of kiln geometry

The present work identifies the basic features of burden movement in a rotary kiln. The cold model study was conducted with iron ore as the feed material to determine the influence of length to diameter ratio (L/D) of a rotary kiln on the filling degree, hold-up, and residence time of the charge. An empirical equation correlating different operating variables has been derived on the basis of the experimental results. The influence of individual parameters under different conditions on the residence time and back spillage has also been evaluated. Formerly Joint Director, Research and Development, TISCO     

Vapour phase crystal growth under microgravity environment

Vapour phase crystal growth experiments performed in the Skylab and ASTP missions are reviewed. The basic vapour phase crystal growth technique is described and effect of gravity is discussed. The multipurpose furnace specially designed to carry out various experiments in flight conditions is described. Ge Se, Ge Te and GeS as well as ternary GeSe_0·99 Te_0·01 and GeS_0·98 Se_0·02 crystals have been grown in space showing improvement over similarly grown crystals on ground as determined by x-ray diffraction, chomical homogeneity and surface morphology studies. Mass flux rates under microgravity conditions have been found to be up to 10 times larger than expected indicating need for better theoretical and experimental understanding of the effect of gravity on crystal growth.     

A semianalytic solution for rectangular plate bending

By substituting the basic function satisfying boundary conditions along two opposite edges in one direction of the plate and then using suitable transformation, the plate bending equation is reduced to an ordinary differential equation. The resulting equation is solved by finite difference technique by using a small number of discrete variables. Examples have been presented for a variety of isotropic and orthotropic elastic rectangular plate of different boundary conditions under various loadings. Excellent accuracy has been obtained.     

Statistical separability of spectral classes of blighted corn

The purpose of this study was to determine the statistical separability of multispectral measurements from corn having varying levels of southern corn leaf blight severity. Multispectral scanner data in twelve spectral channels in the wavelength range 0.4 to 11.7 μm were analyzed for ten selected flightlines of the 1971 Corn Blight Watch Experiment. A total of 168 corn fields having 18,804 sample points were analyzed. The blight rating information for these fields was available from ground observations. Maximum average transformed divergence between spectral classes (found by LARSYS Cluster Algorithm) of all possible pairs of blight levels, maximized over a subset of channels, was computed in each of one, two, three, and four spectral channels for each of ten flightlines. From the statistical analysis of the values of average transformed divergence, it was concluded that the greater the difference between the blight levels, the more statistically separable they are. This result is encouraging considering the fact that there are variables other than the blight severity within and between the flightlines. Although the analysis was done for corn blight only, the conclusions obtained from this analysis may well be applicable to other crop stresses because corn blight is representative of many plant stresses, especially non-systemic stresses.