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...

muhammad ibn muhammad ibn numan, known as "shaykh mufid," one of the great imamiye theologians and jurists in the fourth and early fifth century , had comprehensive mastery of both rational and traditional topics and exerted his influence upon both his contemporary and future scholors. he is considered to be one of the top imamiye scholars who spent his lifetime teaching, learning and authorin...

this study was an attempt to investigate and compare the effect of lexical inferencing and concept mapping on developing vocabulary retention of iranian language learners. sixty homogeneous students from different intact classes who were being taught as intermediate learners in sokhan english institute participated in this study. they were in different classes. a teacher made test as a pre-test...

abstract: about 60% of total premium of insurance industry is pertained?to life policies in the world; while the life insurance total premium in iran is less than 6% of total premium in insurance industry in 2008 (sigma, no 3/2009). among the reasons that discourage the life insurance industry is the problem of adverse selection. adverse selection theory describes a situation where the inf...

since the 1960s the age effects on learning both first and second language have been explored by many linguists and applied linguists (e.g lennerberg, 1967; schachter, 1996; long, 1990) and the existence of critical period for language acquisition was found to be a common ground of all these studies. in spite of some common findings, some issues about the impacts of age on acquiring a second or...

abstract while task-based instruction is considered as the most effective way to learn a language in the related literature, it is oversimplified on various grounds. different variables may affect how students are engaged with not only the language but also with the task itself. the present study was conducted to investigate language and task related engagement on the basis of the task typolog...

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 purpose of this study was to investigate how english language teachers in mashhad who teach students in the pre-university cycle perceived the impact of the efltee on their teaching. the target population was nearly all pre-university english language teachers in seven districts of mashhad in the scholastic year 2008/2009. a survey questionnaire which consisted of (36) likert type items, wa...

1- in a search directed to the reaction of compound)23(the cycloaddition reaction of 1,3- diphenylisobenzofurane)14(with p-benzoquinone)19(,followed by addition of cyclopentadiene was carried out.the specific spacial stracture of its ir,nmr,mass spectra. 2- in another attempt the kinetic stability and behavior of compounds)20(and)23(was studied.the main subject of this study was the highly reve...