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...

abstract: mineral scaling in oil and gas production equipment is one of the most important problem that occurs while water injection and it has been recognized to be a major operational problem. the incompatibility between injected and formation waters may result in inorganic scale precipitation in the equipment and reservoir and then reduction of oil production rate and water injection rate. ...

nowadays,tourism industry considered as one of the main sources of income of a country.unfortunately and despite of owning plenty of cultural historical and natural attractions, iran has not reached to a proper position in this field. besides, the historical cities of a country are considered as the income resource and national wealth of it. qazvin with a rich cultural precedent, have suitable ...

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...

the present study was conducted to investigate the effect of implicit focus on form through input flooding and the effect of noticing, explicit focus on form on linguistic accuracy. to fulfill the purpose of the study, 86 iranian pre-intermediate efl learners of one of the language institutes were chosen by means of administering ket as the homogeneity test. these learners were pretested throug...

language learning courseware has been receiving growing attention by english educators since its advent. a variety of softwares have been designed by software designers and resorted to by language educators to supplement language textbooks. this experimental study investigated how the application of computerized version of language textbooks and the reception of the entire course through comput...

even though, to date, a lot of studies have been conducted on the subject of politeness theory, there are very few studies regarding the applicability of this theory to translation between english and persian which shows the reason behind conducting the present study. this study was carried out with the aim of highlighting whether there is any difference between english and persian methods of u...

the purpose of this quantitative study was to investigate the relation between efl teachers’ self-efficacy beliefs and their success. moreover, the study was an analysis of the teacher age, gender and years of teaching experience, to examine the manner in which these factors relate to teacher self-efficacy as defined by bandura (1997) and teaching effectiveness as evaluated by their own student...

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...

abstract this paper discusses several commonly used models for strategic marketing¹ including market environmental analysis methods (i.e. swot and pest analysis) and strategic marketing tools and techniques (i.e. boston matrix and shell directional policy matrix)and shows how these models may help a firm to achieve its strategic goals. at first, the main reason for doing this research is de...