Growth and characterization of organic material 2-hydroxypyridine single crystal by modified vertical Bridgman technique

Large size (15 mm diameter and 80 mm length) organic material 2-hydroxypyridine single crystal has been grown using the double wall ampoule with nano translation by modified vertical Bridgman tech- nique for the first time. Material of the grown crystal was confirmed by single and powder X-ray diffraction (XRD) measurements. Fourier transform infrared (FTIR) analysis was used to identify the functional groups present in the grown crystal. High resolution X-ray diffraction (HRXRD) has been performed to analyze the crystalline perfection of the grown single crystal. The optical property of the grown crystal was analyzed by UV–vis–NIR and photoluminescence (PL) spectral measurements. The thermal charac- teristics of the grown crystal were analyzed by thermogravimetric (TG) and differential thermal analyses (DTA). The dielectric measurements were carried out with four different frequencies at various temper- atures ranging from 308 to 373 K and the results indicate an increase in the dielectric parameters with the increase of temperature at all frequencies. The second harmonic generation (SHG) studies were used to analyze the nonlinear optical property of the grown crystal

Structural, optical, morphological and SHG studies on 8 MeV electron beam irradiated Sr(HCOO)2·2H2O crystal

Strontium formate dihydrate single crystals have been grown by the slow solvent evaporation method and subjected to 8 MeV electron beam (EB) irradiation at different doses, viz. 1 kGy, 10 kGy, 50 kGy and 100 kGy. The irradiated crystals have been studied by various techniques such as FT-IR, Raman, and UV-Vis-NIR spectral analyses, powder, and high resolution X-ray diffraction, thermogravimetric analysis (TG/DTA) and second harmonic generation (SHG) measurements. The morphological features of the non-irradiated and irradiated crystals were analyzed by SEM and optical microscopy studies. It has been noticed that the SHG efficiency increases while the crystalline perfection and thermal stability of the irradiated crystals decrease with the increase of EB irradiation dose. The results indicate a significant overall tuning of physical properties of strontium formate dihydrate crystals due to irradiation

Chemical characterization of wet precipitation events and deposition of pollutants in coal mining region, India

The present study investigated the chemical composition of wet atmospheric precipitation in India’s richest coal mining belt. Total 418 samples were collected on event basis at six sites from July to October in 2003 and May to October in 2004 and analysed for pH, EC, F−, Cl−, SO2_ 4 , NO_3 , Ca2+, Mg2+, Na+, K+ and NHþ4 . The average pH value (5.7) of the rainwater of the investigated area is alkaline in nature. However, the temporal pH variation showed the alkaline nature during the early phase of monsoonal rainfall but it trends towards acidic during the late and high rainfall periods. The rainwater chemistry of the region showed high contribution of Ca2+ (47%) and NHþ4 (21%) in cations and SO24_ (55%) and Cl− (23%) in anionic abundance. The high non seas salt fraction (nss) of Ca2+ (99%) and Mg2+ (96%) suggests crustal source of the ions, while the high nss SO24_ (96%) and high SO2_ 4 _ NO_3 _ þ C1__ratio signifying the impact of anthropogenic sources and the source of the acidity. The ratio of SO2_ 4 þ NO_3 _ NHþ4 _ þ Ca2þ_varies from 0.03 to 3.23 with the average value of 0.84 suggesting that Ca2+ and NHþ4 play a major role in neutralization processes. The assessment of the wet ionic deposition rates shows no any specific trend, however Ca2+ deposition rate was highest followed by SO2_ 4 and NH4