the importance of writing as a complex skill in applied linguistics has drawn the attention of many researchers to evaluate textbooks in order to help learners gain self-sufficiency and autonomy in the field of language use and communication. investigations have shown that developments in textbooks evaluation can promote the quality of pedagogies and consequently the learning. this study attemp...

in this thesis, a better reaction conditions for the synthesis of spirobarbiturates catalyzed by task-specific ionic liquid (2-hydroxy-n-(2-hydroxyethyl)-n,n-dimethylethanaminium formate), calcium hypochlorite ca(ocl)2 or n-bromosuccinimide (nbs) in the presence of water at room temperature by ultrasonic technique is provided. the design and synthesis of spirocycles is a challenging task becaus...

acknowledge the importance of e-commerce to their countries and to survival of their businesses and in creating and encouraging an atmosphere for the wide adoption and success of e-commerce in the long term. the investment for implementing e-commerce in the public sector is one of the areas which is focused in government‘s action plan for cross-disciplinary it development and e-readiness in go...

in this project, some new polyaspartimides, (pas)s, have been synthesized form michael addition reaction between new synthetic bismaleimide (bmi) and some aromatic diamines. a characteristic property of this polyaspartimides is a pendent carboxylic group, which introduced to these polymers from new bismaleimide. bismaleimides (bmi) is one of the interesting compounds, which can be self-polymeri...

in the first part of this thesis we explored wetting and its dynamics for small droplets. first, we showed how a simple feature of water droplets on a surface, i.e. laplace pressure, can be exploited to build a micropump. we investigated capillary pumping in microchannels both experimentally and numerically. putting two droplets of different sizes at the in/outlet of a microchannel, will ge...

در دنیا مناطقی وجود دارند که ساکنین آنها در معرض پرتوهای طبیعی زمینه بالا هستند. این مناطق به ‏‎high background radiation areas hbras‎‏ ، معروف می باشند. از جمله این مناطق می توان به گوارا پاری در برزیل ، کرالا در هند ، نواحی از آمریکا و یانگ جیانگ در چین اشاره کرد. در ایران نیز مناطق با پرتودهی زمینه بالا مشاهده شده است . رامسر یکی از این مناطق است .

growing demands and requires of high data rate systems cause significant increase of high frequency systems for wideband communication applications. as mixers are one of the main blocks of each receivers and its performance has great impact on receiver’s performance; in this thesis, a new solution for ku-band (12-18 ghz) mixer design in tsmc 0.18 µm is presented. this mixer has high linearity a...

the present research study attempted to find out the extent to which two pre-task activities of “glossary of unknown vocabulary items” and “content related support” assisted efl language learners with their performance on listening comprehension questions across two different proficiency levels (low and high). data for this study were obtained from a total of 120 language learners, female and m...

Habitat heterogeneity plays an important role in increasing species diversity. Heterogeneity of habitats and protected areas can increase the ability of species to adapt to climate change. It is expected that appropriate heterogeneity is necessary for sustainability of protected areas. The influence of altitude on parameters such as temperature and precipitation and the role of microclimates in...