Dr. T. M. Mohan Kumar

Sodium alginate (SA) and graphene oxide (GO) composite pellets are prepared by one step simple procedure. The composites are found to be thermally stable up to 220°C in nitrogen atmosphere. The composite was studied for impedance analysis with varying temperature ranging from room temperature to 170°C. Dielectric constant of the samples was measured using the impedance data using standard formulae. It was found that the dielectric constant of the composites is high at low frequencies which may be due to the contribution from all the dipoles responding to the applied signal. However, at high frequencies, may be due to non-participating dipoles, the dielectric constant of the composites is lower.

A facile and highly responsive spectrophotometric method for the quantification of ultra-trace quantities of chromium(VI) is described. The proposed method is derived from the oxidation of iminodibenzyl (IDB) with chromium in strong acid medium to get a blue coloured product, having λmax at 690 nm. Stability of the colour developed is found to be around 48 h at room temperature. Beer’s law range is observed between 0.02-0.35 µg mL-1 of chromium concentration. The coefficients of molar absorptivity and Sandell’s sensitivity are found to be 1.03 × 105 L mol-1 cm-1 and 0.000523 µg cm-2, respectively where as the detection limit is 0.9 ng mL-1. The method has been optimized for reaction conditions and optical parameters. Tolerance limits for various interfering ions were studied. The efficiency of the method was shown by successful determination of traces of chromium in alloy steel samples. © 2017, Chemical Publishing Co. All rights reserved.

Quality changes in flue cured large cardamom capsules and seeds were monitored under 3 storage conditions: i) 90% RH/38° C (accelerated-humid), ii) 30-40% RH/40° C (accelerated- dry), and iii) 65% RH/27° C (normal) in different packages. The samples were analysed for moisture content, volatile oil content and flavour composition every 30 days for condition (i) upto 120 days and for conditions (ii) and (iii) every 60 days up to 240 days. Capsules packed in unlined high density polyethylene (HDPE) woven sack material, polypropylene ...