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...

drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...

introruction khawf in(iran)-herat and mazaresharif and shirkhan bandar in (afghanistan)-dushanbe in (tajikistan)_(kirgizstan)-kashghar in(china) project railway network is under construction that it is as a significant corridor for revitalizing silk road corridor in the region .at the present there are three different gauge in the region central asia with 1,520 mm gauge and turkey-islamic repu...

abstract in aggregate, active forms of reactive silica with mineral names are sometimes associated with sand and gravel in concrete mixture. alkali hydroxides originated from alkalis in the cement or other resources form an alkaline silica gel with this reactive silica which becomes swallowed and expanded during time causing damage to concrete. there have been growing researches on alkaline r...

armenias geopolitics and its historical experience have had a determining impact on the character of its foreign policy .present-day armenia is a small, landlocked country with _11,620 square miles area armenias landlocked nature makes it dependent on the benevolence of its neighbors for access to the outside world a fact that gives it a sense of isolation and vulnerability. as it was indic...

nowadays, air pollution is a global problem that has had significant growth by technology development, population growth andindustrial development. industrial development brought natural resources deterioration, more manufacturing products, and more environmental pollutants. if pollutant won’t be controlled, human-being and wildlife will face the critical risks. significant release and critical...

the thesis has been arranged into five chapters and mainly concerned with the baer-invariant of groups which is the generalization of the schur-multiplier with respect to the variety of groups. chapter one is devoted to collect some notation and background information which are needed in the next chapters. its also contains some important statements which will be generalized in this thesis. cha...

run-out-table (rot) is located between last finishing stand and down coiler in a hot strip mill. as the hot steel strip passes from rot, water jets impact on it from top and bottom and strip temperature decreases approximately from 800-950 °c to 500-750°c. the temperature history that strip experience while passing through rot affects significantly the metallurgical and mechanical properties, s...

the current study examined iranian undergraduate efl students’ willingness to communicate with regard to their vocabulary knowledge. in general, participants were somewhat willing to communicate in english. the total mean score of 730 university students’ perception of willing to communicate was 83.53 out of 135. results, regarding four parts of willingness to communicate, revealed that part...

the caspian sea contains great resources of oil and gas. the caspian sea is a 700- mile- long body of water in central asia, land located between azerbaijan, iran, kazakhstan, russia and turkmenistan. iran was challenges and opportunities in the caspian region. key question in this thesis includes three section that first question, opportunities of iran in the caspian region, second question ch...