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...

the treatment of in completely formed pulpless teeth has presented considrable problems. these teeth have wide open apexes and the walls of the root canal diverge toward the apical tissues. mechanical preparation cannot be done in the normal manner beacause of the large initial size and the taper of apical part of the canal , a mechanical stop cannot be produced at the apex of the canal and , t...

in recent years many researchers have been focused on interaction of small molecules with dna. dna is generally the primary intracellular of anticancer drugs, so the interaction between small molecules and dna can cause dna damage in cancer cells, blocking the division of cancer cells and resulting in cell death. the flavonoids are a large group of polyphenolic natural products that are widely ...

in this thesis, a better reaction conditions for the synthesis of spirobarbiturates catalyzed by task-specific ionic liquid (2-hydroxy-n-(2-hydroxyethyl)-n,n-dimethylethanaminium formate), calcium hypochlorite ca(ocl)2 or n-bromosuccinimide (nbs) in the presence of water at room temperature by ultrasonic technique is provided. the design and synthesis of spirocycles is a challenging task becaus...

hedging is a multi-purpose rhetorical strategy which is usually used in scientific arguments to secure ratification of claims, reduce the risk of negation, avoid conflict, manage disagreement and leave room for the audience to assess presented information. hedges are frequently used in research articles to mitigate the findings of research endeavors. the present research aims to investigate the...

the purpose of the present study is to find out whether bilinguals of khuzestan-arab origin or monolinguals of iranian origin code-switch during learning or speaking english and which group is more susceptible to code-switch. to this end, the students of 24 classes from high schools and pre- university centers were screened out, and interviewed and their voices and code-switchings were recorded...

abstract: one of the most visited & important spaces in different countries by tourist are urban areas. the old tehran which major part is located in district 12 is historical showcase of the capital, but, its hiidden cultural attraction is not used as it should be. this thesis occasionally engage in studying the efficacy of correct installation of travel guide boards in welfare & easily acc...

the present paper offers a postcolonial reading of two of the best novels by v. s. naipaul – half a life and the mimic men – in five chapters. the focus of this research is on different notions of postcolonial criticism and their application on the two novels as discussed from homi bhabha’s and frantz fanons points of view. having introduced the life and literary career of v. s. naipaul in th...

a major concern in the last few years has been the fact that the cultural centers are keeping distance with what they have been established for and instead of reproducing the hegemony, they have turned into a place for resistance and reproduction of resistance against hegemony. because the cultural centers, as urban public spaces in the last two decades, have been the subject of ideological dis...

هدف تحقیق حاضر بررسی تاثیر نشانه های فرا گفتمان متنی بر فهم متون انگلیسی به وسیله ی زبان اموزان فارسی زبان است.این تحقیق علاوه بر این کوشیده است تا میزان اگاهی این زبان اموزان و نحوه ی تعامل انان را با متون خوانده شده در زبان انگلیسی به وسیله ی پرسش نامه ی تهیه شده بررسی کند.بر اساس محتوای یک متن انگلیسی یازده سوال درست /غلط طرح گردید و یک مرتبه با ان متن و یک مرتبه با نسخه ای که نشانه ها...