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 main purpose of this research was to:1.develop a coking model for thermal cracking of naphtha.2.study coke inhibition methods using different coke inhibitors.developing a coking model in naphtha cracking reactors requires a suitable model of the thermal cracking reactor based on a reliable kinetic model.to obtain reliable results all these models shall be solved simultaneously.for this pu...

testing plays a vital role in any language teaching program. it allows teachers and stakeholders, including program administrators, parents, admissions officers and prospective employers to be assured that the learners are progressing according to an accepted standard (douglas, 2010). the problems currently facing language testers have both practical and theoretical implications but the first i...

any change in the refractive index of a laser active medium can lead to serious degradation of beam quality, laser beam modes, laser performance and variation in the intensity distribution. alteration in the refractive index of laser active medium is especially notable in high power lasers. it is clear that in the laser beam production, the pumping agent induces a great amount of heat which...

the major aim of this study was to investigate the relationship between social and cultural capital and efl students’ critical thinking skills. this study takes this relationship in to account to see if people with different sociocultural status are different regarding their critical thinking skills. to this end, 160 university students majoring in english language and literature, english trans...

according to coates’s (2004, as cited in zhang, 2010) definition of "conversational dominance" (p.111), it refers to the phenomenon of a speaker dominating others in interaction. specifically, it means how a speaker makes use of certain strategies to get the floor and maintain the floor. thus, the amount of talk is the main measurement for the dominance of the conversation. whether a speaker do...

the present study aimed at investigating how different news agencies using the concept of legitimation/delegitimation represent the same event differently. to this end, van leeuwens (2008) legitimatory/delegitimatory framework was applied to the data gleaned from the iranian state-run news agency fars news, british state-run news agency bbc, and also american state-run news agency voa. the resu...

this study purported to compare and contrast the use of self-mention and evidentials as two mtadiscourse features in opinion columns of persian and english newspapers. the theoretical basis of this study is the idea that metadiscourse features vary across cultural boundaries. for this purpose, 150 persian and 150 english opinion columns were collected based on three factors of topic, audience a...

abstract: about 60% of total premium of insurance industry is pertained?to life policies in the world; while the life insurance total premium in iran is less than 6% of total premium in insurance industry in 2008 (sigma, no 3/2009). among the reasons that discourage the life insurance industry is the problem of adverse selection. adverse selection theory describes a situation where the inf...

all analytical methods are generally based on the measurement of a parameter or parameters which are somehow related to the concentration of the species.an ideal analytical method is one in which the concentration of a species can be measured to a high degree precision and accuracy and with a high sensitivity. unfortunately finding such a method is very difficult or sometimes even impossible.in...