Samples of particulate matter less than or equal to 10 μm (PM 10 ) were collected round the clock duration by using a respirable dust sampler (APM 460 BL) in Madurai, the second largest and most densely populated city of Tamil Nadu, India. The Environmental Protection Agency (EPA)-recommended standard methods were adopted not only for sample collection but also for subsequent analysis of respirable particulate pollutants. The observed PM 10 concentrations varied from 88.1 to 226.9 μg/m 3 , and lead concentrations ranged between 0.21 to 1.18 μg/m 3 . The annual averages of the concentrations of the pollutants of current concern manifested that they were mostly below the Indian air quality standards and were generally comparable with those concentrations observed in most other Indian urban areas. The AERMOD model was validated simultaneously by comparing the predicted levels with the estimated levels of PM 10 . The generated database of the present investigation on the degree of pollution may be used for further research investigation and pollution abatement in the city.
Vibrational assignments are proposed for solid NaNH2SO3 on the basis of room temperature polarized Raman spectra of single crystals. Infrared data for the region 4000–50 cm−1 of the polycrystalline sample are also presented. The results indicate that (1) there is no water of crystallization, (2) the hydrogen bonding is extremely weak, and (3) the strength of N—S bond is stronger than in sulphamic acid.
The respirable particulate matter (RPM; PM10) and total suspended particulate matter (TSP) concentrations in ambient air in Tuticorin, India, were preliminarily estimated. Statistical analyses on so-generated database were performed to infer frequency distributions and to identify dominant meteorological factor affecting the pollution levels. Both the RPM and TSP levels were well below the permissible limits set by the US Environmental Protection Agency. As expected, lognormal distribution always fit the data during the study period. However, fit with the normal was also acceptable except for very few seasons. The RPM concentrations ranged between 20.9 and 198.2 μg/m3, while the TSP concentrations varied from 51.5 to 333.3 μg/m3 during the study period. There was a better correlation between PM10–100 and TSP concentrations than that of PM10 (RPM) and TSP concentrations, but the correlation of RPM fraction was also acceptable. It was found that wind speed was the most important meteorological factor affecting the concentrations of the pollutants of present interest. Significant seasonal variations in the pollutant concentrations of present interest were found at 5% significance level except for TSP concentrations in the year 2006.
Raman spectra of a single crystal of calcium sulphamate and polycrystalline barium sulphamate have been recorded at room temperature. Infrared spectra of polycrystalline calcium and barium sulphamates for the region 20-4000 cm-' are also presented. The assignments made are supported by potential energy distribution calculations. The data show that there is no water of hydration in barium sulphamate. The N-S torsional mode is observed in both the compounds. This has not been found in other sulphamates of this family. The results indicate very weak hydrogen bonding in these crystals.
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