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...

abstract compound is a word-formation process that are made two free morpheme (independent) and forms a new word with a new meaning that consists of meaning of both two component of compound. avestan language is one of the ancient iranian languages that is one of the indo-iranian languages. indo-iranian languages is one branch of indo-european languages. structure of compound noun and adjectiv...

tourism , today as one of the ways to make money, create jobs , and social and political interactions is considered. this paper aims to examine the strengths and weaknesses of tourism development in mahmoud abad ( mazandaran ). the research method in this study is " descriptive - analytical " and to collection of data used field methods such as questionnaires and documentation - library. the sa...

testing plays a vital role in any language teaching program. it allows teachers and stakeholders, including program administrators, parents, admissions officers and prospective employers to be assured that the learners are progressing according to an accepted standard (douglas, 2010). the problems currently facing language testers have both practical and theoretical implications but the first i...

the present study aimed at investigating how different news agencies using the concept of legitimation/delegitimation represent the same event differently. to this end, van leeuwens (2008) legitimatory/delegitimatory framework was applied to the data gleaned from the iranian state-run news agency fars news, british state-run news agency bbc, and also american state-run news agency voa. the resu...

the current study examined iranian undergraduate efl students’ willingness to communicate with regard to their vocabulary knowledge. in general, participants were somewhat willing to communicate in english. the total mean score of 730 university students’ perception of willing to communicate was 83.53 out of 135. results, regarding four parts of willingness to communicate, revealed that part...

employees always concern about losing their job , or in other word , losing their income resources. for this purpose, every government requires strong system for covering these concerns. the unemployment insurance (ui) program’s can be used for achieving this goal. in this thesis, we price ui based on the insurance history of employee and the duration of being unemployed. we use the weibull dis...

the study of air infiltration into the buildings is important from several perspectives that may be noted to energy and design of hvac systems, indoor air quality and thermal comfort and design of smoke control systems. given the importance of this issue, an experimental and numerical study of air infiltration through conventional doors and windows has been explored in iran. to this end, at fir...

there is less published research about how teachers in efl contexts respond to students who are relatively less mature and less competent l2 writers. while writing researchers have examined various issues concerning peer and teacher response in writing-oriented classes, little research has centered on the effect of collaborative tasks particularly dictogloss on writing skills. output collaborat...

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...