cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...

the purpose of this study was to investigate the impact of blended learning and multimedia softwares on iranian efl students vocabulary learning. in addition, the present study tried to examine the extent to which multimedia softwares can be applied into efl classes in iran. it also attempted to find out students attitudes toward using these softwares. to this end, 87 iranian efl learners at el...

there are two major theories of measurement in psychometrics: classical test theory (ctt) and item-response theory (irt). despite its widespread and long use, ctt has a number of shortcomings, which make it problematic to be used for practical and theoretical purposes. irt tries to solve these shortcomings, and provide better and more dependable answers. one of the applications of irt is the as...

the aim of conducting this study was to investigate the foreign language learning needs of undergraduate economics students and business management students in faculties of social sciences of alzahra and azad naragh university. in the study, which was designed on the basis of a qualitative-quantitative basis using interviews and questionnaires, 146 female undergraduate business management as we...

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...

vocabulary as a major component of language learning has been the object of numerous studies each of which has its own contribution to the field. finding the best way of learning the words deeply and extensively is the common objective of most of those studies. however, one effective way for achieving this goal is somehow neglected in the field. using a variety of activities such as games can r...

nanotechnology is a general term which is related with field of all advanced science term that generally predicates with all modern technologies which consider nanoscales. improvement in the quality of products by adding some nanoparticles and study of their behavior in the presence of these nanoparticles have been obtained in many researches. on the other hand numerous demands for sowing ...

in this thesis, a new optically active poly(amide-imide) (pai) was synthesized by the indirect polycondensation reaction of the l-phenylalanine based diacid chloride and 4,4?-diaminodiphenylether in the presence of triethylamine in n-methyl-2-pyrrolidone. the formation of pai was confirmed by ftir, 1h nmr and elemental analysis. in next step, the surface of titanium dioxide (tio2) nanoparticles...

a novel ultra wideband microstrip bandpass filter using radial stub loaded resonator and interdigital coupled lines is presented in this paper. the radial stub loaded resonator and decagonal patch form a resonator named m to create tuneable multiple notches in the passband for suppression wlan interference. to realize sharp roll-off, two adjustable transmission nulls are located at the lower an...

abstract the present study was conducted to examine the effect of proficiency on students interaction while carrying out the grammar-based task(s) in collaboration. in particular, the study examines whether the level of proficiency affects the learners’ focus of attention to grammatical and lexical features. the study takes a further step and examines whether there is any difference in the use...