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 in aggregate, active forms of reactive silica with mineral names are sometimes associated with sand and gravel in concrete mixture. alkali hydroxides originated from alkalis in the cement or other resources form an alkaline silica gel with this reactive silica which becomes swallowed and expanded during time causing damage to concrete. there have been growing researches on alkaline r...

abstract: the present study is about prophet ishmael, some parts of his life; his personality in the quran and the bible; and the comparison of the content of these two religious books. compilation of the study has been done with a new perspective and new presentation approach. since prophets have been human beings’ role model and their life has been a perfect example for humanity in all ages,...

The arrangement of verses in the Quranic surahs, the proximity of the surahs and the congruence between the surahs of the same group have always been one of the important issues in Quranic sciences, which has been dealt with under such titles as the order of the verses and the congruence of the surahs. The network associations of the Quranic surahs is a new term that speaks of the structural an...

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...

abstract this study evaluates the iranian pre-university english textbook in terms of needs, objectives, content, and methodology. the study was designed on the qualitative- quantitative survey basis using interviews and questionnaires, a researcher-made textbook evaluation checklist and a needs analysis questionnaire. the textbook evaluation questionnaire was used in this study to elicit the ...

abstract present research considered to examine and compare shahrray 14 years girls and boys narrative concerning with their responsibilities in this research, statistical society are 14 years girls and boys of shahrry . for performing this research. first, 14 years of 50 boys and 50 girls were selected in accidental method and have filled memati hormaled adolescents responsibility questioner...

abstract english language learning in iran has become significant in recent years, and english has been included in the curriculum of iranian schools and universities, and considerable attention has been paid to this language in our society. nevertheless, teaching and learning english in iranian schools has not been able to satisfy the specified goals, so different efl institutes have been est...

the study reflected in this thesis aims at finding out relationships between critical thinking (ct), and the reading sections of tofel and ielts tests. the study tries to find any relationships between the ct ability of students and their performance on reading tests of tofel and academic ielts. however, no research has ever been conducted to investigate the relationship between ct and the read...