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A study into occurrence of fire in opencast workings over developed coal pillars and evolving control parameters for its safe extraction

Panigrahi D., Sinha S. K., Singh G. N.

Archives of Mining Sciences

2013

Vol. 58, no. 4

1145--1162

In India, a number of opencast mines are being worked over the coal pillars developed by underground bord and pillar method of mining. In these cases, the fires have occurred in most of these opencast mines causing loss of the coal reserve, production, productivity and safety. In this research work, 13 such mines have been studied over a period of three years and critical parameters for occurrence of these fires have been identified. This paper presents the details of observations for two such mines and detailed statistical analyses have been carried out by using confidence interval (C.I.) and analysis of variance (ANOVA-Two-way classification) for finding out the range of these critical parameters which can be controlled to reduce the occurrence of these fires.

W wielu kopalniach odkrywkowych w Indiach wydobycie prowadzi się w wyrobiskach ponad filarami ochronnymi udostępnianymi przy wykorzystaniu metody filarowo-komorowej. W takich warunkach powstające często w kopalniach pożary powodują utratę zasobów węglowych, zmniejszenie wydajności i poziomu wydobycia oraz negatywnie wpływają na bezpieczeństwo pracy. W artykule tym przeanalizowano przypadki 13 kopalni odkrywkowych na przestrzeni trzech lat, zidentyfikowano krytyczne parametry dla określenia możliwości wystąpienia pożaru. Artykuł przedstawia dokładne obserwacje poczynione w dwóch kopalniach, poparte szczegółową analizą statystyczną z zastosowaniem przedziałów ufności i analizy wariancji (ANOVA - klasyfikacja dwukierunkowa) do określenia wartości parametrów krytycznych w celu zminimalizowania ryzyka wystąpienia pożarów.

Development and validation of an RP-HPLC method for simultaneous analysis of drotaverine and omeprazole in a tablet dosage form

Panigrahi D., Sharma R.

Acta Chromatographica

2008

Vol. 20, no. 3

439-450

A simple, rapid reversed-phase high-performance liquid chromatographic method has been developed and validated for simultaneous estimation of drotaverine and omeprazole in a tablet dosage form. A C 18 column was used with a 60:40 ( v/v ) mixture of methanol and ammonium acetate (0.1 M , pH 5, adjusted with orthophosphoric acid) as mobile phase at a flow rate of 1.5 mL min -1 . UV detection was performed at 319 nm. The method was validated for accuracy, precision, linearity, specificity and sensitivity in accordance with International Conference on Harmonisation guidelines. The method was successfully used for quantitative analysis of Ranipas-DV tablets. Total run time was 10 min, drotaverine and omeprazole were eluted with retention times of 7.969 and 6.538 min respectively. Validation revealed that the method is specific, accurate, precise, reliable and reproducible. Calibration plots were linear over the concentration ranges 5-40 µg mL -1 for drotaverine and 5-50 µg mL -1 for omeprazole, respectively. Limits of detection were 16.2 and 4.8 ng mL -1 and limits of quantification were 49.0 and 14.5 ng mL -1 for drotaverine and omeprazole, respectively. Recovery was in the range 100.66-100.94% and 102.42-102.89% for drotaverine and omeprazole, respectively, and the coefficient of variance was <2.0% for both. The high percentage recovery and low co-efficient of variation confirm the suitability of the method for simultaneous analysis of drotaverine and omeprazole in tablets.