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...

chapter one is devoted to a moderate discussion on preliminaries, according to our requirements. chapter two which is based on our work in (24) is devoted introducting weighted semigroups (s, w), and studying some famous function spaces on them, especially the relations between go (s, w) and other function speces are invesigated. in fact this chapter is a complement to (32). one of the main fea...

chapter one is devotod to collect some notion and background informations, which are needed in the next chapters. it also contains some important statements which will be proved in a more general context later in this thesis. in chapter two, we show that if the marginal factor-group is of order np1...pk,n>1, then we obtain a bound for the order of the verbal subgroup. also a bound for the bear-...

there has been a gradual shift of focus from the study of rule systems, which have increasingly been regarded as impoverished, … to the study of systems of principles, which appear to occupy a much more central position in determining the character and variety of possible human languages. there is a set of absolute universals, notions and principles existing in ug which do not vary from one ...

asymmetric polyethersulfone (pes) microfiltration flat sheet membranes were composed by the phase inversion method (pim) and were used as supports. composite membranes were fabricated by coating silicone rubber as selective layer. effect of different concentrations of pes and pdms and different solvent such as nmp, dmf and dms effects as pes solvents and support thickness and different coagulat...

the present study reports an analysis of response articles in four different disciplines in the social sciences, i.e., linguistics, english for specific purposes (esp), accounting, and psychology. the study has three phases: micro analysis, macro analysis, and e-mail interview. the results of the micro analysis indicate that a three-level linguistic pattern is used by the writers in order to cr...

the significance of the study of deixis was then mentioned. the purpose of the present study from the outset was to provide a comprehensive overview of all kinds of deixis in persian, describing and defining each in true while considering them structurally and semantically. chapter two consisted of two main parts. a review of the english studies in this respect, besides presenting persian liter...

many mobile and off-grid devices include electronics and other electrical consumers like servo drives, which need a quite low supply power. since the price for photovoltaic modules drops continuously, photovoltaic power supply is interesting in more and more applications. in solar powered systems, a battery is needed to store energy for the night and cloudy periods. the power electronics of suc...

the present thesis is a study of postmodern historical novel with respect to the voice of women. according to postmodern historiography,the established institution of history is one of the other manifestations of patriarchys power which has silenced women. the study analyzes angela carters nights at the circus as a postmodern historical novel which makes its female characters transgress the pat...