abstract in this research the thermal stratification of the water in the torogh dam basin and the resulted changes in its quality with respect to temperature, salinity and dissolved oxygen was investigated using the dynamic reservoir simulation model. the results indicated that in wet years such as 1998, when the average annual precipitation and the resulted inflows to the basin is higher than ...

The Western Airborne Contaminants Assessment Project showed that USA National Parks had fish mercury (Hg) concentrations above threshold concentrations set for wildlife. Since significant areas of the Western USA are arid, we hypothesized that dry deposition would be important. The primary question was whether sources of Hg were local and thus, easily addressed, or regional (from within the Uni...

Phylogenetic reconstruction using the mitochondrial 16S marker shows that geographically separated populations of the poorly known Hyperolius cinereus (Anura: Hyperoliidae) from Angola form two distinct clades. The description of H. cinereus was originally based on only a single preserved adult male. Fresh material of both sexes allowed a detailed redescription of the species, which is restrict...

The effects of initial spacing layout on some allometric characteristics of 12-year-old Quercus castaneifolia trees grown in Central Mazandaran, north of Iran were examined. Trees were planted in 5 different layouts (1?1, 1.5?1.5, 2?2.5, 2?3 and 4?4 m). Tree height, diameter at breast height, natural pruning height and the survival of trees were recorded in each sample plot. Tree basal area and...

This paper uses two-dimensional Finite Element Method (FEM) numerical modeling to analyze the orientation of maximum horizontal tensional stress of the Barapukuria coal basin in Bangladesh. An elastic plane stress model incorporating elastic rock physical properties for the coal basin area was used consisting of 2916 elements with a network of 1540 nodes. The stress field at any point of the mo...

background: a new biological domestic wastewater treatment process, which has been presented these days in activated sludge modification, is upflow sludge blanket filtration (usbf). this process is aerobic and acts by using a sludge blanket in the separator of sedimentation tank. all biological flocs and suspended solids, which are presented in the aeration basin, pas through this blanket. the ...