Optical reflectance of the quasi two dimensional compound Hg₂.₈₆AsF₆ has been investigated in the optical range, 0.5 to 4 eV. The spectra clearly show a plasma edge at 3 eV. They are fitted to a Drude model and two Lorentz oscillators. From the plasma frequency and the model parameters values for the dc conductivity and the effective mass and an estimate of the crytsal anisotropy have been obtained. The results compare well with earlier electrical measurements on this compound. / Thesis / Master of Science (MSc)

Black carbon has been reported to have major impacts on climate, environmental quality, and health. A chemothermal oxidation method, ordinarily used to isolate black carbon from soils, sediments and aquatic samples was applied to explore atmospheric samples. The results were then compared with thermal optical reflectance measurements, and then investigated in parallel with a health survey conducted during sampling. This study assesses atmospheric emissions from the NTPC Farakka coal-fired power plant in West Bengal, the distribution of emissions, the mobilization of black carbon, and its impact on pulmonary and cardiovascular conditions among respondents in Murshidabad and Malda, in West Bengal, India. Two measurement campaigns were conducted during winter and summer (November 2021 – June 2022); a total of 81 samples (Murshidabad) and 65 samples (Malda) were collected and analyzed and 193 respondents were surveyed for lung functionality. Over the study period, the mean concentration of PM2.5 and soot were observed to be 147 μg/m³; 113 μg/m³ and 1.52 μg/m³; 1.54 μg/m³ respectively. From the spirometry tests, it was concluded that there was chronic exposure to PM2.5 at both the sites, during the winter and monsoon campaigns. With increases in PM2.5 corresponding with higher numbers of restrictive and obstructive cases.