in the first chapter we study the necessary background of structure of commutators of operators and show what the commutator of two operators on a separable hilbert space looks like. in the second chapter we study basic property of jb and jb-algebras, jc and jc-algebras. the purpose of this chapter is to describe derivations of reversible jc-algebras in term of derivations of b (h) which are we...

Resources are the foundation of economic growth. With speedy economic and population growth, economic growth is facing a scarcity of resources worldwide. Resource-economy co-ordination has become every government’s main focus in reaching strategic development goals in countries that are on the path of rapid economic development. Sustainable economic development in a country requires resources a...

within the components of communicative competence, a special emphasis is put on the “rules of politeness,” specifically the politeness strategies (brown and levinson, 1978) that speakers deploy when performing the request speech act. this is because the degree of imposition that making a request places upon one’s interlocutor(s) has been seen to be influenced by several factors among which, as ...

the study of air infiltration into the buildings is important from several perspectives that may be noted to energy and design of hvac systems, indoor air quality and thermal comfort and design of smoke control systems. given the importance of this issue, an experimental and numerical study of air infiltration through conventional doors and windows has been explored in iran. to this end, at fir...

the present study is an experimental case study which investigates the impacts, if any, of skopos on syntactic features of the target text. two test groups each consisting of 10 ma students translated a set of sentences selected from advertising texts in the operative and informative mode. the resulting target texts were then statistically analyzed in terms of the number of words, phrases, si...