The scope of magnesium oxychloride (MOC) cement in concrete works has been evaluated. MOC cement concrete compositions of varying strengths having good placing and finishing characteristics were prepared and investigated for their compressive and flexural strengths, E-values, abrasion resistance etc. The durability of MOC concrete compositions against extreme environmental conditions viz. heating-cooling, freezing-thawing, wetting-drying and penetration and deposition of salts etc were investigated. The results reveal that MOC concrete has high compressive strength associated with high flexural strength and the ratio of compressive to flexural strength varies between 6 and 8. The elastic moduli of the compositions studied are found to be 23-85 GPa and the abrasion losses between 0⋅11 and 0⋅20%. While alternate heating-cooling cycles have no adverse effect on MOC concrete, it can be made durable against freezing-thawing and the excessive exposure to water and salt attack by replacing 10% magnesium chloride solution by magnesium sulphate solution of the same concentration.

In this work, a comprehensive review of technologies employing radiation sources such as microwave, ultrasonic, and radio frequency (RF) on gas hydrates is presented. The characterizing parameters of radiation, such as frequency, wavelength, and power are highlighted for the compiled studies. In addition, characterizing parameters like hydrate dissociation rate, irradiated microwave power, complete dissociation time, reaction paths and mechanisms, differential pressure and temperature of gas hydrates during the experiments are also reported. Moreover, the work also describes the basic concept behind the working of the different wave forms such as microwaves, ultrasonic, RF wave and plasma for hydrate dissociation.

A fugacity-based thermodynamic model for hydrate has been used to determine the equilibrium pressures of hydrate formation. This fugacity-based model uses the PRSV equation of state, which is used to represent the gas phases in the hydrate. The parameters of the model are fitted to the experimental data of binary guest hydrates. The present study is aimed at investigating binary mixtures of CH 4 -H 2 S, C 3 H 8 -N 2 , N 2 -CO 2 , CH 4 -i-butane, C 3 H 8 -i-butane, CH 4 -n-butane, C 3 H 8 -n-butane, i-butane-CO 2 , and n-butane-CO 2 hydrates, which have not been modeled before. Unlike previous studies, the Kihara potential parameters were obtained using the second virial coefficient correlation and the data of viscosity for gases. The fugacity-based model provides reasonably good predictions for most of the binary guest hydrates (CH 4 -C 3 H 8 ). However it does not yield good prediction for hydrates of (CO 2 -C 3 H 8 ). The transitions of hydrate structure from sI to sII and from sII to sI have been also predicted by this model for binary guest hydrates. The AAD % calculated using the experimental data of natural gas hydrates is only 10 %, which is much lower than the AAD % calculated for the equilibrium data predicted by the VdP-w model.

Relationship between compression (V/V0) and pressure have been studied for five bulk metallic glasses (BMGs) viz. Zr41Ti14Cu12.5Ni10Be22.5, Zr41Ti14Cu12.5Ni9Be22.5C1, Zr48Nb8Cu12Fe8Be24, (Zr0.59Ti0.06Cu0.22Ni0.13)85.7Al14.3and SiO2.TiO2in the compression ranges of V/V0=1.00 to V/V0= 0.10. Six forms of equation of state reported in the literature have been used in the present study to calculate pressure corresponding to different values of compressions. The comparison of graph plotted between the logarithms of calculated value of pressure to logarithm of calculated value of compression (V/V0) reveals that the agreement of Brennan-Stacey equation of state (EOS) and Poirier-Tarantolla equation of state are not good. It has been found that the assumptions, on which these equations are based, do not satisfy well in case of given BMGs.