since the 1960s the age effects on learning both first and second language have been explored by many linguists and applied linguists (e.g lennerberg, 1967; schachter, 1996; long, 1990) and the existence of critical period for language acquisition was found to be a common ground of all these studies. in spite of some common findings, some issues about the impacts of age on acquiring a second or...

‎in this article‎, ‎we have focused one some basic and productive information about the properties of spectrum and singular values related to compact operators which are ideals in a c*-algebra of bounded operators‎. ‎considering a two-sided connection between the family of symmetric gauge functions on sequence of singular values of compact operators and symmetric norms on finite dimensional ope...

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...

the concepts of similarity and dissimilarity have been the interest of many researchers. basically, in the studies the similarity between two objects or phenomena, has been discussed. in this thesis, we consider the case when the resemblance or similarity among three objects or phenomena of a set, 3-similarity in our terminology, is desired. later we will extend our definitions and propos...

attempts have been made to study the thermodynamic behavior of 1,3 butadiene purification columns with the aim of retrofitting those columns to more energy efficient separation schemes. 1,3 butadiene is purified in two columns in series through being separated from methyl acetylene and 1,2 butadiene in the first and second column respectively. comparisons have been made among different therm...

this study aims to investigate value conflicts between mothers and their daughters among families and influential factors on this conflict in yazd city. this study adopted a survey method and a questionnaire was used that its validity through construct validity (factor analysis) and its reliability by cronbach alpha were measured. the population of this study consists of all yazdian families th...

abstract in first part of this project, the use of a new and biguanid-like catalyst supported on silica as a recyclable catalyst provides a new route for the synthesis of a variety of arylalkylidene rhodanine derivatives through knoevenagle reaction in at present of solvent at room temperature. rhodanine derivatives and especially arylalkylidene rhodanines have proven to be attractive compound...

the present study aimed at exploring cognitions of iranian english teachers within the context of english for academic purposes (eap). to this end, the cognitions of two groups of eap teachers with respect to their pedagogical content knowledge (pck) and their sense of professional identity (pi) were probed. two language teachers and two content instructors who had at least five years of eap te...

this dissertation has six chapter and tree appendices. chapter 1 introduces the thesis proposal including description of problem, key questions, hypothesis, backgrounds and review of literature, research objectives, methodology and theoretical concepts (key terms) taken the literature and facilitate an understanding of national security, national interest and turkish- israeli relations concepts...

we have devided the thesis in to five chapters. the first recollects facts from purely algebraic theory of jordan algebras and also basic properties of jb and jb* - algebras which are needed in the sequel. in the second chapter we extend to jb* - algebras, a classical result due to cleveland [8]. this result shows shows the weakness of jb* - norm topology on a jb* - algebera. in chapter three, ...