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The samples of Thar coalfield were characterized using a thermogravimetric analyzer, atomic absorption spectrophotometer, X-ray diffractometer, Fourier transform infrared spectra, and scanning electron microscopy-energy dispersive x-ray spectroscopy analysis. The samples were ranked as lignite and subbituminous according to American Society for Testing and Materials standard classification. Differential thermogravimetric analysis results specified chemical reactivity of coal at the primary devolatilization region (257-412 ı C) and secondary devolatilization region (741-900 ı C). The minerals identified were quartz, kaolinite, dikite, halloysite, gold copper indium, graphite hydrogen nitrate, and magnesium vanadium molybdenum oxide. X-ray diffraction study confirmed the presence of mineral constituents as indicated by microscopic investigation. Fourier transform infrared spectra identified CDC aromatic groups at 1,500-1,700 cm 1 as maturity indicator and 2,800-3,000 cm 1 and 2,300 cm 1 as aliphatic stretching regions. The peaks of quartz and kaolinite were observed at 900-1,100 cm 1 . Strong correlations between mineral matter-SiO 2 .r 2 D 0:808/ and Al 2 O 3 -SiO 2 .r 2 D 0:957/ indicates Al and Si as the dominant inorganic components. Cluster analysis appeared as an additional tool for coal ranking based on their physicochemical properties.

The surface of Thar coal has been characterized by spectroscopic, microscopic and chemical methods using atomic absorption spectroscopy, fourier transform infrared analysis, X-ray diffraction, scanned electron microscopy and pH titration. The samples contained high moisture, low volatile and low to moderate sulfur content and ranked as lignite (heating value 2541-4289 kcal/kg on moist, mineral-matter-free basis). Scanned electron micrographs show porous matrix with calcium, potassium or sodium minerals. Fourier transform infrared analysis also confirmed the presence of aluminum, silica and hydrate mineral constituents. The spectra showed C=C aromatic groups at 1604-1609 cm-1. Phenolic ester and carboxylic acid are identified by C=O stretching vibration peaks at 1702 cm-1. The peaks of quartz and kaolinite were observed at 900-1100 cm-1. Point of zero charge of Thar coal has been estimated as 6.00 to 6.27 through adsorption of H + and OHions by suspending coal particles in aqueous electrolyte solution. Oxygen containing functional groups, mineral matter, and metal oxides are found to have a remarkable impact on point of zero charge. The surface characterization study will be helpful in the separation of hydrophilic impurities during coal preparation processes considering pzc as the controlling factor.

Piperidine derivatives are known to exhibit analgesic activities and are likely to possess the ability to block the effects of prostaglandins through inhibition of downstream signaling pathways. The present study investigated the activity of five derivatives (PD2-6) of 4-(4'-bromophenyl)-4-piperidinol (PD1), against pain and platelet aggregation mediated by the release of prostaglandins and thromboxane A2, respectively. The results showed that compound PD1 and its two phenacyl derivatives PD3 and PD5 exhibited a highly significant analgesic effect (p < 0.01), whereas PD4 and PD6 also showed significant activity. PD3, the most active analgesic compound when docked to the opioid receptor, had interactions between the oxygen of its nitro group and the amino group of ARG 573, indicating a distance of 1.2563 Å. The antiplatelet data showed that compound PD5 (4-(4'-bromo-phenyl)-4-hydroxy-1-[2-(2″,4″-dimethoxyphenyl)-2-oxo-ethyl]-piperidinium bromide) had an IC(50) = 0.06 mM, which was the most active compound, whereas PD3 was the second most active compound against platelet aggregating factor-induced aggregation with an IC(50) = 80 mM. Acetyl salicylic acid (IC(50) = 150 μM) was used as a positive control.

Piperidine derivatives are reported to exhibit a variety of pharmacological activities. In this article, synthesis and aspartic protease inhibitory activity of three nitrophenacyl derivatives of N-methyl-4-hydroxy piperidine are reported. Enzyme assays showed that the attachment of a nitro group in the benzene ring plays an important role in the inhibition of plasmepsin-II of Plasmodium falciparum. The compound 1-methyl-1-(4'-nitrophenacyl)-4-hydroxypiperidinium bromide (3), consisting of a nitro group at the para position, was the most active at the concentration of 1.0 µM. The activity of the compounds was evaluated through the observed orientation and diagrammatic representation of nitrophenacyl derivatives of 4-hydroxy piperidine.