the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...

the effect of the presence of perforations on he stresses of a plate is a problem which is of great interest in structural design and in the mathemattical theory of elasticity. among the many hole patterns that are likely to require consideration is the ring of equally spaced circular holes. the present worke investigates stress & strain analysis of a thin isotropic circular plate containing a ...

abstract following innovations in the field of elt, a new topic which has recently attracted a lot of attention is metaphor analysis. although this area of research is still in its infancy in elt, it seems that the idea can shed more light on the puzzle of english language learning and teaching. therefore, the major aim of this study is to analyze language learning and teaching in formal a...

nowadays enhancing critical thinking in learners is considered one of the foreign language teachers’ tasks due to its high position in foreign language classrooms. when it comes to selecting materials for language classrooms, there are obviously some criteria that teachers should apply. the present study aimed at a critical thinking based analysis of ten picture story books and ten folktales th...

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...

چکیده نمایشگاه های جهانی یا اکسپو عنوانی ست که از سال 1851 میلادی در لندن توسط همسر ملکه انگلستان شکل گرفت ، هدف اولیه این نمایشگاه ها نمایش دستاورد های صنعتی بود، اما در طول 165 سال که این نمایشگاه های برگزار گردیدند ، رویکرد آنها تغییر کرده است . در هر دوره به یک شعار که در واقع دغدغه اصلی جهان، در آن زمان بوده است ، پاسخ داده شده و راه حل کشور های مختلف در مورد آن موضوع به نمایش گذارده شد...

according to webster and wind (1972) and anderson et al (1987), “organizational buying is a complex process and involves many people from different functional areas, multiple goals and potentially conflicting decision criteria. moreover, the customers of today are also more knowledgeable and selective when making their purchasing decisions. since a key to organizational survival is the retentio...

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...

the main purpose of the present study was to investigate the relationship between listening proficiency and metacognitive listening strategies awareness among low, mid, and highly self-regulated students. three hundred and seventy one efl students participated in this study (all grade 3 and 4 high-school students who were studying in khansar in academic year 1391-92). to gather the data, three ...

this study intends to investigate samuel beckett’s waiting for godot and endgame under the lacanian psychoanalysis. it begins by explaining the most important concepts of lacanian psychoanalysis. the beckettian characters are studied regarding their state of unconscious, and not the state of consciousness as is common in most beckett studies. according to lacan, language plays the sole role in ...