fluoride is one of the most important elements in the composition of teeth and bones. this element can enter the body via different ways. however, drinking water is the most important way to receive fluoride by a lot of people. an increase in fluoride level in the body causes dental fluorosis and its absence leads to teeth decay. standard rate of fluoride in drinking water is determined by the ...

Evapotranspiration (ET) plays a significant role in regional and global climates through its partitioning in hydrological cycles, and its estimation is thus of a great importance in assessing ground water and surface water resources, predicting crop yield and planning land use. For experimenting the possibility to assess the hydrological responses of ecological restoration in the Western Chines...

The earth's surface, due to its natural conditions and its structure is always changing and reshaping. One of the created deformations is the land subsidence. This is the most dangerous events which can be seen in most urban areas especially in the agricultural plains today. This study aims at zoning land subsidence and recognition of geometrical factors in southwest of Tehran. To estimate and ...

The present paper deals with development of a simulation model for the performance evaluation of feed water system of a thermal power plant using Markov Birth-Death process and probabilistic approach. In present paper, the feed water system consists of four subsystems. After drawing transition diagram for feed water system, differential equations are developed and then solved recursively using ...

In drylands, both dust storms and ephemeral salt lakes (playas) are common. Observations using remote sensing and ground studies have shown that these playas can be major sources of saline dust storms. Some basins have recently become desiccated as a result of water abstraction by humans, and these have become significant sources of dust. The timing and amounts of dust emissions depends on such...