Jai Krishna Pandey

Biomarkers: A potential prognostic tool for silicosis

Long-term exposure to respirable dust containing silica leads to pneumoconiosis/silicosis. The disease is irreversible and incurable, and only preventive steps such as job rotation, use of personal protective equipment, etc., remain solutions to the problem. Under such a situation, early diagnosis or prediction may become very useful to control the disease. Biomarkers are biological parameters in blood serum that change their values with deposition of dust in the lung and onset of lung fibrosis. Since these biomarkers can help us to diagnose and in the prognosis of the disease before it is actually diagnosed by the conventional X-ray technique and lung function test used for diagnosis of silicosis. The present paper describes the various types of available biomarkers, their application and usefulness. The paper also suggests that further study of the behavior/level of these biomarkers on a specific subject with time may provide more useful information of a confirmatory nature for prevention of dust-linked diseases.

Evaluation of Quartz Reduction by Coal Cleaning for Thermal Utilization of an Indian Coal

ABSTRACT In Indian coals, quartz is abundantly found and its proportion usually varies from 5–20% by weight. Beneficiation of high-ash thermal coals of India has become the prerequisite for improving the overall economics and efficiency of power generation. A detailed survey of literature reveals that no systematic work has been done of beneficiated coal for Indian coals with respect to quartz, as also for correlation with abrasion. Therefore, to understand this effect different sizes of crushed coal were subjected to float-sink treatment at specific gravities in the range of 1.30– 1.80. This study highlights the systematic method of measuring crystalline silica (α-quartz) in bulk coal samples using NIST-SRM 1878a as a calibration standard with more accuracy by FT-IR as well as distribution of quartz in various screen sizes, float-and-sink fractions, for both the feed and clean coal. The results show that there is a linear relationship between ash % and quartz % with respect to specific gravity for all screen sizes. Characterization of the feed and clean coal with respect to quartz was also done using XRD, SEM, and XRF spectroscopic techniques to evaluate the reduction behavior of quartz during the coal-cleaning process.

Ventilation Design of Long Sub-surface Headings during Drivage

Adequate ventilation at workplace is necessary to ensure safety and efficiency of workers which, in turn, are essential for optimising production and productivity for given set of conditions. Ventilation of long heading drivages pose additional constraints as total air requirement for diluting pollutants and meeting breathing needs has to be taken through a duct which is characterised by high resistance and its leakiness. This requires a careful and judicious selection of various design parameters viz., type and size of duct, fan type, number and their installation location to ensure adequate ventilation requirement. Such exercise often involves lengthy and cumbersome computational work to arrive at an optimum and energy efficient configuration of ventilation system.