in this thesis, first the notion of weak mutual associativity (w.m.a.) and the necessary and sufficient condition for a $(l,gamma)$-associated hypersemigroup $(h, ast)$ derived from some family of $lesssim$-preordered semigroups to be a hypergroup, are given. second, by proving the fact that the concrete categories, semihypergroups and hypergroups have not free objects we will introduce t...

abstract amino acids are building blocks of proteins, and play a vital role in living beings existence and their functionality. the interaction of these compounds with metal ions is of great importance to biochemists, and chemists, because their functions can be utilized as a model in understanding enzymes mechanism for transport of metal ions to tissues. among twenty essential amino acids w...

to explore the idea the investingation proposed, aimed at finding whether the performances of the population of iranians students studying english in an efl context are consistent in l1 and l2 writing taks and whether there is a cross-linguistic transfer in this respect. in this regard the subjects were instructed to write four compositions-two in english and two in farsi-which consisted of an ...

in one pole of the continuum of language learning, theoreticians and practitioners traditionally consider english as english as a second language or english as a foreign language. however, in the other pole of this continuum where english is thought of as the most effective tool for international communication, it is referred to as a lingua franca. those who favor an approach to english growing...

based on the latest records of typhlops vermicularis merrem, 1820 from iran, this species is distributed in the northern and southern regions of the country. in this study, new records of typhlops vermicularis are presented and it is shown that distribution range of this species is extended towards the eastern and western iran, and according to the new distribution map, it can be assumed that t...

cultural iran is a scope that is more extended than the political territories of iran as a political unit. this concept means that cultural geography(mehdi moghanlo-1383-1) of iran is greater than its political geography which, according to history, has a long history extending west-east from kandahar to the euphrates and north-south from the persian gulf to the caucasus including transoxiana a...

abstract tasks nowadays are at the center of attention in sla research. task types is one of the critical issues in this regard, their effectiveness and suitability to any particular context, their characteristics and the result they yield are among some of these issues. on the other hand, discourse markers (dms) have been very much investigated and their effectiveness in conveying the meaning...

learning a second or foreign language requires the manipulation of four main skills, namely, listening, reading, speaking, and writing which lead to effective communication. it is obvious that vocabulary is an indispensible part of any communication, so without a vocabulary, no meaningful communication can take place and meaningful communication relies heavily on vocabulary. one fundamental fac...

these days, all department stores make an effort to provide their clients with valuable products in order to project the best image for them. as a result, clients’ comprehension risk will decrease and they will be more willing to repurchase. having a good image is really important for the department stores because it makes an impression on clients’ comprehension of both quality and risk. consid...

some researches made in the field of agency problem issue, deal with the role of control systems regarding owners and managers. in this research the relationship between the two control mechanisms, namely the voluntary disclosure (external control mechanism) and outside directors (internal control mechanism), which are reductive of agency problems, has been studied. for this reason, a sample ...