boron nitride semiconducting zigzag swcnt, $b_{cb}$$n_{cn}$$c_{1-cb-cn}$, as a potential candidate for making nanoelectronic devices was examined. in contrast to the previous dft calculations, wherein just one boron and nitrogen doping configuration have been considered, here for the average over all possible configurations, density of states (dos) was calculated in terms of boron and nitrogen ...

chapter one is devotod to collect some notion and background informations, which are needed in the next chapters. it also contains some important statements which will be proved in a more general context later in this thesis. in chapter two, we show that if the marginal factor-group is of order np1...pk,n>1, then we obtain a bound for the order of the verbal subgroup. also a bound for the bear-...

introduction acetic acid bacteria are large group of obligate aerobic gram negative bacteria with the ability to oxidize ethanol to acetic acid (1). they are widely distributed in natural habitats and classified in family acetobacteraceae. members of this family are useful in industrial production of vinegar(2). acetic acid bacteria (aab) can use substrates as glucose, ethanol, lactate or glyc...

the application of e-learning systems - as one of the solutions to the issue of anywhere and anytime learning – is increasingly spreading in the area of education. content management - one of the most important parts of any e-learning system- is in the concern of tutors and teachers through which they can obtain means and paths to achieve the goals of the course and learning objectives. e-learn...

hydrochlorothiazide (hct) is a diuretic agent which is shown to be effective in the treatment of hypertension. literature reports have demonstrated that urinary excretion data may be used to assess the bioavailability of various formulations containing this thiazide. also hct consumption by the athletes is one of the drugs which should be regulated by world anti-doping agency (wada), because of...

the extent to which written corrective feedback on linguistic errors can play a role in helping l2 writers improve the accuracy of their writing continues to be an issue of interest to researchers and teachers since truscott (1996) mounted a case for its abolition. while there is growing empirical evidence that written corrective feedback can successfully target some types of linguistic error (...

the purpose of the present study was to see which one of the two instruction-processing instruction (pi) and meaningful output based instruction (mobi) accompanied with prompt and recast- is more effective on efl learners’ writing accuracy. in order to homogenize the participants in term of language proficiency a preliminary english test (pet) was administrated between 74 intermediate students ...

a large number of single research studies on the effects of strategy-based instruction (sbi) in teaching english as a foreign or second language has been conducted so far. however, the lack of a comprehensive meta-analysis targeting the effectiveness of english language sbi is observed. moreover, the findings of experimental studies regarding the context of the english language, proficiency lev...

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...

cohesion is an indispensable linguistic feature in discourse analysis. lexicald such a differe cohesion and conjunction in particular as two crucial elements to textual cohesion and comprehension has been the focus of a wide range of studies up to now. yet the relationship between the open register and cohesive devices has not been thoroughly investigated in discourse studies. this study concen...