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...

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...

Background: Impaired balance is one of the most common symptoms that occur after stroke. There are several tests for evaluating balance in neurological disorders. Brief-balance evaluation systems test (Brief-BESTest) is the short version of BESTest that assess the systems contributing to postural control. The purpose of this study was to investigate the inter- and intra-rater reliability of the...

Organizations may attract human capital to fill pivotal positions in two ways, namely internal attraction and external attraction. Applying internal recruitment, organizations attract idiosyncratic human capital. Idiosyncratic human capital is exclusively unique to the organization and is defined with such criteria as long experience and internship (intra-organizational training). Yet, by exter...

until now many studies have been done over recent decades throughout the world to show the right age to start english. in iran, research is still at an early stage in terms of evaluating teachers’ beliefs about teaching children english. the problem of at what age to start teaching english and how to teach english to elementary school children has not been solved neither in this country nor els...

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...