many mobile and off-grid devices include electronics and other electrical consumers like servo drives, which need a quite low supply power. since the price for photovoltaic modules drops continuously, photovoltaic power supply is interesting in more and more applications. in solar powered systems, a battery is needed to store energy for the night and cloudy periods. the power electronics of suc...

in the area of automotive engineering there is a tendency to more electrification of power train. in this work control of an induction machine for the application of electric vehicle is investigated. through the changing operating point of the machine, adapting the rotor magnetization current seems to be useful to increase the machines efficiency. in the literature there are many approaches wh...

abstract the present study deals with a comparison between reactive and pre-emptive focus-on-form in terms of application and efficiency. it was conducted in an intermediate english class in shahroud. 15 male learners participated in this research and their age ranged from 18 to 25. a course book, new interchange 3, and a complementary book were used. every session the learners gave lectures o...

abstract: the present study is an attempt to find out cultural exophoric references in iranian high-school elt textbooks and touch stone series to compare the frequency of occurrence of such references in these books. the purpose is to find out which of the series of the books under investigation impose a greater referential burden on efl learners as far as their reading comprehension of the ...

abstract part one: the electrode oxidation potentials of a series of eighteen n-hydroxy compounds in aqueous solution were calculated based on a proper thermodynamic cycle. the dft method at the level of b3lyp-6-31g(d,p) was used to calculate the gas-phase free energy differences ,and the polarizable continuum model (pcm) was applied to describe the solvent and its interaction with n-hydroxy ...

efl/esl textbooks have been regarded as essential language teaching materials with which the learners spend about 70 up to 90 percent of their class time. the important role they play and their vast use make them not only influential in learning the language but also in shaping values and attitudes. put it another way, textbooks socialize learners using their contents (i.e. texts, illustrations...

abstract listening is a key and main tool in second language skill and its development is of prime concern to teachers and learners. furthermore, the application of technology in language classrooms has become more commonplace in the last fifty years. computer and the internet have made foreign language materials easy to access and use. so, the present study is an attempt to examine the effec...

the space now known as complete erdos space ec was introduced by paul erdos in 1940 as the closed subspace of the hilbert space ?2 consisting of all vectors such that every coordinate is in the convergent sequence {0} ? { 1 n : n ? n}. in a solution to a problem posed by lex g. oversteegen we present simple and useful topological characterizations of ec. as an application we determine the ...

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 ...

iv abstract this study examined the linguistic behaviors of two iranian efl teachers each of them teaching learners of two similar proficiency levels, a beginner level and an intermediate level, to investigate the relationship between the learners proficiency levels and the amounts and purposes for l1 use by the two teachers. the study was carried out to investigate whether there were differe...