in this investigation the effect of external field on the electron density of nanostructures of cds, cdse, cdte, gaas and polymeric structure of three, four, five and six units of cds as a kind of nanosolar cells has been studied theoretically. as modeling this system in nanodimension, molecular structures has used. specific properties of molecular structures permit us to consider different sym...

this ethnographic case study research was carried out in a private school setting in the context of iran. the research tried to explore the analysis and identity construction of a group of learners and teachers along with the content analysis of books on the basis of four types of commodified, political, national and narrative identities. how english language learners and teachers in an informa...

implicit and unobserved errors and vulnerabilities issues usually arise in cryptographic protocols and especially in authentication protocols. this may enable an attacker to make serious damages to the desired system, such as having the access to or changing secret documents, interfering in bank transactions, having access to users’ accounts, or may be having the control all over the syste...

bekenstein and hawking by introducing temperature and every black hole has entropy and using the first law of thermodynamic for black holes showed that this entropy changes with the event horizon surface. bekenstein and hawking entropy equation is valid for the black holes obeying einstein general relativity theory. however, from one side einstein relativity in some cases fails to explain expe...

in the present work, a simple and sensitive method was developed for determination of morphine and heroin using gold nanoparticles as resonance rayleigh scattering (rrs) and colorimetric technique’s probe. synthesized gold nanoparticles by sodium citrate reduction method have a negative charge layer on their surfaces because of self-assembled citrate anions on their surface. binding of morphin...

abstract the current study set out to address the issue as to whether the implementation of portfolio assessment would give rise to iranian pre-intermediate efl learner autonomy. participants comprised 60 female in pre-intermediate level within the age range of 16-28.they were selected from among 90 language learners based on their scores on language proficiency test -key english test. then, t...

most specialists in the field of foreign language teachingconsiderreading skill as an interactive process between the reader’s prior knowledge and the text.accordingly, the activation of prior knowledge for an effective comprehension is very important. it is generally agreed that the pre-reading phase is the stage where this type of interaction and activation may be enhanced throughcertain stra...

this study investigated the effects of planning on second-language written production with regard to task type. the participants were 75 iranian learners of english as a foreign language attending a private foreign language institution. they were asked to complete two different types of writing tasks (expository writing task and argumentative writing task) in different planned conditions (indiv...

the purpose of this study is identifying effective factors which make customers shop online in iran and investigating the importance of discovered factors in online customers’ decision. in the identifying phase, to discover the factors affecting online shopping behavior of customers in iran, the derived reference model summarizing antecedents of online shopping proposed by change et al. was us...

the purpose of the present study was to investigate the relationship between fear of negative evaluation (fne) and communication strategies (css) among iranian efl learners. it was aimed to examine the differences in the use of communication strategies between speakers with high or low degree of fear of negative evaluation. the current study was a case study consisting of 10 english learners at...