asymmetric membranes are widely used in many industrial membrane separation processes. the major advantage of membrane filtration over the conventional process is its ability to remove a wider spectrum of particles without using any chemicals. hollow fiber configuration offer many advantages over flat-sheet or tubular membranes. the spinning process of hollow fiber may look simple, yet it is te...

to explore the idea the investingation proposed, aimed at finding whether the performances of the population of iranians students studying english in an efl context are consistent in l1 and l2 writing taks and whether there is a cross-linguistic transfer in this respect. in this regard the subjects were instructed to write four compositions-two in english and two in farsi-which consisted of an ...

in this study, scour of mashkid bridge pier located in mashkid river of saravan county has been studied and to measure the scour rate, the numerical model hec-ras 4.0 has been used. upon selection of mashkid river as the case study and whereas the studied zone is important with respect to the climatic conditions and showery monsoon raining and flowing the great and destructive floodwaters, ther...

abstract the aim of this study was threefold: (1) to investigate the relationship between knowledge of semantic prosody and efl learners general language proficiency; (2) to examine the relationship between qualitative as well as quantitative knowledge of words, and (3) to compare the performance of efl learner on receptive and productive measures of semantic prosody. the study is based on a...

in the first part of this thesis we explored wetting and its dynamics for small droplets. first, we showed how a simple feature of water droplets on a surface, i.e. laplace pressure, can be exploited to build a micropump. we investigated capillary pumping in microchannels both experimentally and numerically. putting two droplets of different sizes at the in/outlet of a microchannel, will ge...

abstract there is not much sources about ancient carnival and ceremonies , but some information can be gain from documents . as a matter of fact the ceremonies were a part of zarartiyan principles which zartosht had taken them to his religion . it should be mentioned that the oldest ceremonies are about poster and agriculture principles this seasonal ceremonies were very important for agri...

this study was intended to analyze the listening tapescripts of the elementary and pre-intermediate levels of total english textbooks from the pragmatic dimension of language functions and speech acts in order to see whether the listening tasks are pragmatically informative or not. for this purpose, 8 conversations from the two books were selected randomly, and then, the two pragmatic models of...

it is not possible to understand developments of a country’s culture and civilization without knowing his believes and myths. whether it is north or south, east or west, planes or mountains, sahara or deserts, here in iran every corner includes valuable and precious treasures which are known all over the world, and cultural – historical objects which are found here adorn all well known museums...

abstract since heubners (1985) pioneering study, there have been many studies on (mis) use/ non-use of articles by l2 learners from article-less and article languages. the present study investigated how persian l2 learners of english produce and interpret english definite descriptions and demonstrative descriptions. it was assumed that definite and demonstrative descriptions share the same cen...

this study was conducted to investigate the impact of portfolio assessment as a process-oriented assessment mechanism on iranian efl students’ english writing and its subskills of focus, elaboration, organization, conventions, and vocabulary. out of ninety juniors majoring in english literature and translation at the university of isfahan, sixty one of them who were at the same level of writing...