abstract nowadays, industries cannot play a crucial role in national and international competitions. the tourism industry is no exception. tourism industry development as the most important economic sector and income generation is one of the key challenges of economic development in the world. therefore, countries were successful that take advantage of the capabilities of tourism sector using ...

among the low–dimensional allotropes of carbon, nanotubes and graphene have attracted very much attention from nano–science and nanotechnology specialists. they have been proposed as building blocks in nanometer device engineering. however, these structures are not defect–free. in this thesis, we focused on defective carbon nanotubes and graphene, and studied the effect of couple of very common...

this study investigates the strategies native english and persian speakers employ for expressing gratitude in different situations. the strategies of persian efl learners are also compared with english strategies in order to find the differences that may exist between these two languages. social status and size of imposition of the favor are social variables which are investigated in detail for...

an investigation into oral interaction in language classes: a conversation analytic point of view the aim of this thesis is to analyze the interaction between language teachers and students in english language institutes. this work is done in the context of yasuj city. learning another language, which is in most cases english, involves many variables. one of these variables is the linguistic...

in this project, 4,4?-methylenebis(3-chloro-2,6-diethyl trimellitimidobenzene) as a diacid, was prepared by the reaction of trimellitic anhydride (tma) with 4,4?-methylenebis(3-chloro-2,6-diethylaniline) (mcdea). the novel poly(amide-imide) (pai) was synthesized from the reaction of 4,4?-methylenebis(3-chloro-2,6-diethyl trimellitimidobenzene) as a diacid with mcdea under green condition using ...

due to the limiting workspace of parallel manipulator and regarding to finding the trajectory planning of singularity free at workspace is difficult, so finding a best solution that can develop a technique to determine the singularity-free zones in the workspace of parallel manipulators is highly important. in this thesis a simple and new technique are presented to determine the maximal singula...

in this research we have studied the effect of some transition-metals (cu, ag and au) substitutions on two-electron reduction potential of flavins by application of dft method. all geometries have been optimized at blyp level of theory and “6-31+g** + lanl2dz” mixed basis set. the frequency job at the same method and basis sets has been performed to obtain gibbs free energy of compounds. it h...

assigning premium to the insurance contract in iran mostly has based on some old rules have been authorized by government, in such a situation predicting premium by analyzing database and it’s characteristics will be definitely such a big mistake. therefore the most beneficial information one can gathered from these data is the amount of loss happens during one contract to predicting insurance ...

while performance-based language assessment has led to an increased authenticity and content validity in the practice of writing assessment, the reliability of ratings has become a major issue. research findings have shown different reactions by native english speaker (nes) and non-native english speaker (nns) teachers to students’ writings. the focus of this study is on investigating whether i...

this study was conducted to investigate the impact of podcasts as a learning and teaching tool on iranian efl learners’ motivation for listening as well as on their listening comprehension ability. the study also investigated the learners’ perception towards listening to podcasts and examined whether the learners were likely to accept podcasts. out of fifty-five intermediate learners studying e...