Synthesis, growth and characterization of L-Leucine Magnesium Nitrate Hexahydrate crystal

L-Leucine Magnesium Nitrate HexaHydrate ([Formula: see text]) crystal is a nonlinear optical (NLO) material of semiorganic type. It has grown using a slow evaporation solution growth (SEST) technique at elevated temperature (40∘C) by dissolving LL+MNHH in double distilled water. It was crystalized and recrystalized from a supersaturated solution by stirring it for several hours to get high optical perfection. The X-ray diffraction studies confirmed the presence of the intermixed compound in the [Formula: see text] crystal and possess monoclinic structure. Fourier transform infrared spectroscopy (FTIR) spectrum identified the functional groups of the grown crystal. The crystal has very good optical absorption and transparency in the UV–Vis region. The thermal analysis revealed the thermal stability of the crystal. The dielectric study shows that dielectric constant and dielectric loss decrease at higher frequencies. The crystal showed nonlinear property by second-harmonic generation (SHG) study. This type of material with fair nonlinearity is useful in optoelectronics application devices.

Improving the Performance of Solar Heat Collector Using Molten Salts

An individual solar collector and two partly freight cylinders filled with molten salts embedded storage tank were connected to each other and forced circulated water by electric pump to improve the thermal performance of residential solar hot water tank. Multi flow rates of 25, 50 and 70 l/h. used to achieve an appropriate flow rate of circulating water. The calcium nitrate tetra hydrate Ca(NO3)2-4H2O and magnesium nitrate hex hydrate Mg(NO3)2-6H2O were mixed to form cheap binary molten salts base on different weight ratios. These molten salts combined could be used as both sensible heat materials and latent heat storage materials, besides they can directly use as heat transfer fluid due to freezing temperature. Six samples of different mixing ratio of molten salts had tested to assess the thermal analysis of each sample. The result indicated that the mixture 60%Ca(NO3)2+40%Mg(NO3)2 had the best performance for thermal storage tank with melting point of 38°C and the thermal value is 8.7 mW, and thermal stability of molten salts were noticed by DSC 60 SHIMADZSU devise.

Experimental Research of the Heat Storage Performance of a Magnesium Nitrate Hexahydrate-Based Phase Change Material for Building Heating

Phase change heat storage material is a preferred material in solar building heating or off-peak electric-heat storage heating technology and is the research focus. A compact phase change thermal storage device has been designed and experimentally studied for improving heating system load in this work. A new type, magnesium nitrate hexahydrate-based phase change material has been studied to improve the cooling degree and crystallization difficulty. The focus of this study is on the heat charging and discharging characteristics of this new phase change material. The heat storage device has two groups of coils, the inner side which carries water and the outer side which is the phase change material. A testing system was built up to value the thermal cycling performance of the heat storage device. The measurement data include phase change material temperature field, water inlet and water outlet mean temperature, heat charging and heat discharging depth, and flow rates over the operating period. The results show the phase change material has a quick response with the operating temperature range of 20–99 °C. Its latent heat is 151.3 J/g at 91.8 °C. The heat storage density of this phase change material is about 420 MJ/m3. The thermal performance degradation is about 1.8% after 800 operation cycles. The phase change thermal storage device shows flexibility and a great potential to improve the capacity and economy of heating systems.

EVALUATION OF PROPERTIES OF NON-STOICHOMETRIC ALUMINA MAGNESIA SPINEL USING THIOUREA AS FUEL BY VARYING SOAKING TIME

The present article reports a simple and cost-effective process to prepare the crystalline MgAl2O4 spinel using non-stoichometric amount of magnesium nitrate, aluminium nitrate by solution combustion route. Thiourea was used as a fuel and reducing agent while soaking was carried at 1000ºC with different soaking periods. After slow drying of mixed solutions at 80ºC for 4-5 hours a gel was formed and got characterized by DTA/TGA (Differential Thermal Analysis and Thermal Gravimetric Analysis) to observe the effect of temperature variation and identify the range of temperature where crystalline nature of the powder was noted. Powder sample was prepared from the gel after annealing at 1000ºC followed by soaking for 4 hours, 5 hours, 6 hours to compare the variation of particle size with respect to time. The calcined powders were characterized by XRD (X-ray powder diffraction) to determine the phases and crystal planes present in the sample, FT-IR (Fourier-transform infrared spectroscopy) to study the types of metal oxide or metal-metal bond present in the sample along with M-O coordination studies, FESEM (Field emission scanning electron microscopy) to observe the morphological structure of the sample, EDAX (Energy Dispersive X-Ray Analysis) to observe the percentage of each element present in the sample. Bulk densities were estimated from 2.4156 g/cm3 to 2.8571 g/cm3 and the rapid increase in apparent porosity of samples 7.4289%, 10.3630% and 32.51% for 4 hours 5 hours and 6 hours respectively were also noted. It had been observed that the average crystal size of spinel particles was about 48 nm, 36 nm, and 47 nm respectively. Finally, hardness of spinel was evaluated by Vicker Hardness test and evaluated to be10.52GPa (1073 HV), 4.087GPa (416.7HV) and 5.079 GPa (517.9HV).

Evaluation of effect of synthesis parameters on the morphology of nano-structures of magnesium oxide coated with carbon

In this study, the influence of the synthesis parameters on the microstructural properties of nanoparticles of magnesium oxide coated with carbon was investigated. The nanostructures were produced in a one-step synthesis procedure, following a sol-gel method, and the effects of the molar ratio between magnesium nitrate and glucose, the temperature and the dripping time on the morphology of the nanostructures formed were analyzed. The results indicate that an increase in carbon concentration, synthesis temperature around 60 °C and 4 h of dripping time favor the formation of small agglomerates of nanoparticles with greater carbon coating homogeneity. In general, high synthesis temperatures favor the kinetic aspects of crystallization and produce nanostructures with a larger crystallite size. On the other hand, altering the dripping time was not efficient in changing the morphology of the nanostructures obtained. In addition, increasing the carbon concentration favors the formation of structures with small surface area and pore volume.

Physico-Chemical Studies of Ground Water and Filter Water Samples in Ramanagra Taluk, Ramanagara District, Karnataka, India

The main objective of our study was to convey the importance of water to mankind. We can survive without food for several weeks, because our body will gradually switch to using stored fat and protein to make its energy, but cutoff of water supply leads to death of mankind within few days. Around two third of our body is water. On average we need 2.4 liters of water on each day to keep us healthy that’s the only reason people spend so much of money on water filters that will remove harmful impurities. In the early ages before the existence of filters, tubehole water was one of the sources of drinking water in our taluk. But according to the analysis in the recent years we found that this tubehole water had contamination of fluoride (2). In the later years many research scholars took initiative for the removal of fluoride in the tubehole water. This initiated us to make a comparative study to assess the quality of both filter and tubehole water found in the region of Ramanagara Taluk. Unfortunately through our research we found that some of the water samples were unfit for drinking. Water samples of few areas were selected for qualitative analysis of water. Water samples were analyzed for examination of pH, alkalinity, acidity, conductivity, total dissolved solids (TDS), total hardness, calcium, chlorine, magnesium, nitrate, fluoride and sulphate. It is important to monitor the physical properties of both filter and tubehole water, as it is a early warning signal that something is happening to water.