ground water and surface water create a range of problems in lignite mining utilizing surface mining methods. in order to create a safe and economic mining environment, it is essential to carry out mining after dewatering the rock mass surrounding the lignite mines by advance dewatering techniques. this paper briefly describes the ground water regimes including pressure gradients associated wit...

“In the thermodynamic limit the canonical and the microcanonical ensemble are equivalent in all details and generality. ” Statements like this are found in many textbooks of statistical thermodynamics. It is the purpose of this contribution to show that this is not so, and, more importantly, that the microcanonical ensemble allows for significant insight into the mechanism of first order phase-...

Conventional material removal of BK7 optical glass will normally result in brittle fracture at the surface, generating severe subsurface damage and poor surface finish. Subsurface damages induced by grinding strongly influence the mechanical strength and optical quality of optical glasses. However, through ductile mode grinding it is possible to reduce the surface and subsurface cracks. It is m...

Excess lead in drinking water is a neglected source of lead toxicity in Pakistan. A cross-sectional survey in 2007/08 was made of water samples from drinking water sources in Karachi, a large industrial city. This study aimed to compare lead levels between untreated ground water and treated surface (tap) water in 18 different districts. Of 216 ground and surface water samples collected, 86% had...

The mechanism of earthquake energy input to building structures is clarified by considering the surface ground amplification and soil-structure interaction. The earthquake input energies to superstructures, soil-foundation systems and total swaying-rocking system are obtained by taking the corresponding appropriate free bodies into account and defining the energy transfer functions. It has been...

forests are an important economic source for human and have key role in nutrient cycle, hydrology and ecosystem performance, any interference in this vital ecosystem causes to damage to forests. mechanical logging and road construction in forest areas have led to much soil compaction. soil physical and chemical properties were studied in parts of road and non-road in the darabkola forest of ira...

This paper investigate a low altitude air-to-ground channel over a sea surface in the tropical region at C band. It is found that, compared to a high altitude air-to-ground channel where a free space propagation condition can be assumed, the sea surface reflection and other multipath propagation phenomena for lower altitude air-to-ground channel can readily be observed. Therefore, for low altit...

Conventional material removal of BK7 optical glass will normally result in brittle fracture at the surface, generating severe subsurface damage and poor surface finish. Subsurface damages induced by grinding strongly influence the mechanical strength and optical quality of optical glasses. However, through ductile mode grinding it is possible to reduce the surface and subsurface cracks. It is m...