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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 a stability-indicating HPTLC method for analysis of 3-acetyl-11-keto-β-boswellic acid in a herbal extract and a nanoparticles formulation

Goel A., Goel R., Jain G. K., Singh R. M., Ahmad F. J., Singh G. N.

Acta Chromatographica

2008

Vol. 20, no. 3

497-511

A new, specific, sensitive, selective, precise, and reproducible high-performance thin-layer chromatographic (HPTLC) method has been established for study of the stability of 3-acetyl-11-keto-β-boswellic acid (AKBA). HPTLC was performed on aluminium foil plates coated with 200 µm silica gel 60F 254 . Linear ascending development with toluene-ethyl acetate 7:3 ( v/v ) was performed at room temperature (25 š 2°C) in a twin-trough glass chamber saturated with mobile phase vapour. Compact bands ( R 0.52 š 0.02) were obtained for AKBA. Spectrodensitometric scanning was performed in absorbance mode at 250 nm. Linear regression analysis of the calibration plots showed there was a good linear relationship ( r 2 = 0.9989 š 0.0002) between peak area and concentration in the range 200-1200 ng band -1 . The method was validated for precision, recovery, robustness, specificity, and detection and quantification limits, in accordance with ICH guidelines. The limits of detection and quantification were 3.06 and 9.29 ng band -1, respectively. The recovery of the method was 99.35-100.21%. AKBA was subjected to various stress test conditions - acid and alkali hydrolysis, oxidation, photodegradation, and dry and wet heat treatment. Degradation products were well resolved from the pure drug with significantly different R F values. Statistical analysis showed the method could be successfully applied for the estimation of AKBA in herbal extract and in nanoparticles. Because the method could effectively separate the drug from its degradation products, it can be regarded as stability-indicating.