abstract the purpose of this study was to find out the effect of applying the principles of group-dynamic assessment (g-da) on learning of conditional structures in english by iranian efl learners at the intermediate level, which according to the formal educational system in iran, includes students who are in their second year of studying in high schools of koohdasht city. this study was a qua...

attempts have been made to study the thermodynamic behavior of 1,3 butadiene purification columns with the aim of retrofitting those columns to more energy efficient separation schemes. 1,3 butadiene is purified in two columns in series through being separated from methyl acetylene and 1,2 butadiene in the first and second column respectively. comparisons have been made among different therm...