any change in the refractive index of a laser active medium can lead to serious degradation of beam quality, laser beam modes, laser performance and variation in the intensity distribution. alteration in the refractive index of laser active medium is especially notable in high power lasers. it is clear that in the laser beam production, the pumping agent induces a great amount of heat which...

writing an academic article requires the researchers to provide support for their works by learning how to cite the works of others. various studies regarding the analysis of citation in m.a theses have been done, while little work has been done on comparison of citations among elt scopus journal articles, and so the dearth of research in this area demands for further investigation into citatio...

during the process of reading, sometimes learners use ineffective and inefficient strategies and some factors may influence their use of strategies. perhaps critical thinking is one of these factors. this study aims to identify those categories of reading strategies that are mostly used by iranian efl learners and to see if there is any significant relationship between the critical thinking abi...

target tracking is the tracking of an object in an image sequence. target tracking in image sequence consists of two different parts: 1- moving target detection 2- tracking of moving target. in some of the tracking algorithms these two parts are combined as a single algorithm. the main goal in this thesis is to provide a new framework for effective tracking of different kinds of moving target...

the construct of self-efficacy has received increasing attention in research over the past two decades. many studies have been carried out 1.3 significance of the study this study has pedagogical implications since improving students’ self- efficacy and autonomy is important for promoting actual performance on classroom academic tasks. in academic settings, it has been shown that self-effi...

this study was designed and conducted to find out if there is any significant relationship between iranian efl learners preferance for one of the three degrees of obtrusiveness in foreign language instruction (focus on form, forms and meaning) and their preferred experiential learing style. to collect the data two questionnaires were used. the first one on the degree of obtrusiveness and the se...

due to lack of knowledge management system in the organization of technical and vocational university of iran (tvuni) and losing good employees because of retirement and substitution causes huge amount of costs to replace the similar expertise. there is no any suitable system in the tvuni to store, to document, and to distribute knowledge. based on the university’s features such as it has diffe...

increasing academic and professional language demands around the world are not a deniable fact. the purpose of this study was to investigate english language needs and communication needs of the chemistry students at master and ph.d. levels at the iranian universities. in this research, different methods were used including un-structured interview, structured interview, and two sets of question...

abstract since heubners (1985) pioneering study, there have been many studies on (mis) use/ non-use of articles by l2 learners from article-less and article languages. the present study investigated how persian l2 learners of english produce and interpret english definite descriptions and demonstrative descriptions. it was assumed that definite and demonstrative descriptions share the same cen...

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...