let h be a separable hilbert space and let b be the set of bessel sequences in h. by using several interesting results in operator theory we study some topological properties of frames and riesz bases by constructing a banach space structure on b. the convergence of a sequence of elements in b is de_ned and we determine whether important properties of the sequence is preserved under the con...

learning english is very popular all over the world nowadays and it is considered a high prestigious language among citizens of different societies. one of the most important materials for learning a new language are textbooks. the debate that whether learning a new language is natural and neutral or ideological and influential on people’s worldviews, has always been of great importance.

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...

this work is presented in five parts. in the first part preparation of the starting complex [pt(c^n)cl(dmso)], 1, in which c^n = n(1),c(2?)-chelated, deprotonated 2-phenylpyridine, and dmso = dimethylsulfoxide, and its reaction with 1 equiv of the biphosphine ligands bis(diphenylphosphino)amine, dppa, or bis(diphenylphosphino)methane, dppm, to give the complex [pt(c^n)cl(dppa)], 2, or [pt(c^n)c...

nowadays, the development of anti cancer drugs is an important subject in pharmacology. bisphosphonates (b.p) are a great choice for design and production of the types of drugs which not only could perform as anti cancer agents but also could inhibit the function of acetyl cholinesterase (ache). ache hydrolyzes the acetylcholine (which is a neurotransmitter in nervous system) using the oh in i...

this study tried to explore disciplinary variations of web blurbs across soft and hard knowledge fields on the one hand, and to illustrate how academic publishers exploit interactional metadiscourse devices in move structure of their blurbs on the other.

august wilson is undoubtedly one of the rare black playwrights whose works have attracted streams of attention and worldwide audience. the present study aims at analyzing fences and piano lesson which are two of the most successful plays in his pittsburgh cycle from the perspective of michel foucault’s theories and ideas. studying these two plays from foucault’s perspective opens new windows in...

the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...

abstract because of the many geopolitical, geo economical and geo strategically potentials and communicational capabilities of eco region, members can expand the convergence and the integration in base of this organization that have important impact on members development and expanding peace in international and regional level. based on quality analyzing of library findings and experts interv...

abstract abstract of thesis (includes summary, goals, execution methods, and results) story “al-obnosat al-bayza” is one of the short stories from “hanna mineh” collection. this story is a selection of lives of some humans during a voyage together, each of them is a symbol of human nature (love, mind, kindness) and examine social, cultural, and political aspects of governing system, and it...