intense temperature variations are not only an unfavorable phenomenon for life but have adverse effects on natural elements of structures and installations. when the temperature falls bellow certain levels, the conditions for organic activity become harsh. this level is known as temperature threshold of life. similar thresholds can also be defined for machinery, structures and installations. fu...

in this paper the minimum temperatures of 54 weather stations collected for a 31-year period were analyzed for zoning the frost regions in iran. the results of this study show that the average of the number of frost days per year was 62, and the average temperature was 3 degrees of centigrade below zero. dey the tenth month in the iranian calendar, december 22-january 20 with an average of 28, ...

A molecular model is proposed of a bilayer consisting of fully saturated dipalmitoylphosphatidylcholine (DPPC) and mono-unsaturated dioleoylphosphatidylcholine (DOPC). The model not only encompasses the constant density within the hydrophobic core of the bilayer, but also the tendency of chain segments to align. It is solved within self-consistent field theory. A model bilayer of DPPC undergoes...

nowadays, in consideration of environmental issues and limitation of fossil fuels, there is a particular consideration of renewable energy including ocean energy, that can extracted going through various methods such as wave energy, tidal energy, salinity gradient, otec: ocean thermal energy conversion.herein this research, operation of otec method in southern caspian sea has been discussed. fo...

Nowadays, in consideration of environmental issues and limitation of fossil fuels, there is a particular consideration of renewable energy including Ocean Energy, that can extracted going through various methods such as Wave Energy, Tidal Energy, Salinity Gradient, OTEC: Ocean Thermal Energy Conversion.Herein this research, operation of OTEC Method in Southern Caspian Sea has been discussed. Fo...

The effect of decreasing environmental temperature on membrane phospholipids (PL), the neutral lipid (NL) composition, and their fatty acid profiles was studied in exponentially growing Candida utilis from 40 to 10 degrees C, at intervals of 5-9 centigrade degrees. According to the results, fatty acid unsaturation increased with decreasing growth temperature from 40 to 26-20 degrees C, due to t...

Effectiveness of furfural as an organic inhibitor in 5 percent hydrochloric acid which is used in acid pickling of steel was evaluated. Lungmuir, Frumkin and Flory-Huggins isotherms [1, 2] were used to determine the parameters of effective adsorption, free energy and entropy of adsorption. Furfural indicated an inhibition less than 17 percent in concentrations of 0.001 mole per liter for a dura...

Effectiveness of furfural as an organic inhibitor in 5 percent hydrochloric acid which is used in acid pickling of steel was evaluated. Lungmuir, Frumkin and Flory-Huggins isotherms [1, 2] were used to determine the parameters of effective adsorption, free energy and entropy of adsorption. Furfural indicated an inhibition less than 17 percent in concentrations of 0.001 mole per liter for a dura...