nowadays,it is important to consider environmental issues,as ecological problems and their severe effect intensify in iran,particularly in khuzestan province.the environmental effects of hydroelectric plants are highly regarded due to their significant impact on an extensive area.the lack of safe path for fish passing through the turbines is one of these damages. in order to deal with these cha...

introduction: the aim of this study was to evaluate and compare microhybride composite treated by bur and different power of erbium, chromium doped yttrium scandium gallium garnet (er,cr:ysgg) laser by scanning electron microscope (sem). methods: 21 microhybride composite blocks (diafil tm, diadent, korea) with 2 × 4 × 4 mm dimensions were made. the bonding surface of these blocks were polished...

the concept of countervailing power is a term to describe the situation in which the market power of one side (sellers) may be balanced by the market power of another side(buyers) in a given market. the purpose of this paper is to test this hypothesis and to determine whether the market power of sellers has had a restraining influence on increases in buyer market power in iran’s large industrie...

introduction: the aim of this study was to evaluate the composite surface treated by different powers of erbium-doped yttrium aluminum garnet (er:yag) laser in comparison with bur preparation via scanning electron microscope. methods: fourteen composite resin blocks with 15× 10 × 10 mm dimensions were used in this study. the samples were divided to seven groups as follow: group 1 (power: 1 w, e...