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...

the neogene intrusion masses in the noudeh-enghelab area located to the north of sabzevar ophiolite have cut the late cretaceous ophiolitic rocks, sedimentary- volcanic and eocene volcanic rocks and have been covered by pliocene and quaternary deposits. the margin is of lava with basalt, phyric andesite-basalt and andesite and the central parts (dome shaped) composed of phyric andesite-trachyan...

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...

deposite the different criticisms on contrastive analysis it has been proved that the results of it(when processed)can be usuful in a tefl environment,specially at the level of phonology.this study is an attempt to compare and contrast the sound systems of kurdish and english for pedagogical aims. the consonants,vowels,stress and intonation of the twolanguages are described by the same model-ta...

abstract the third millennium has started, but the world is facing with serious challenges in achieving international security and peace. various human rights violations have lead the states to find means to protect human rights. also article 55 of the united nations charter introduces the respect to human rights and fundamental freedom as the most suitable ways to realize peace and security. ...

increasing academic and professional language demands around the world are not a deniable fact. the purpose of this study was to investigate english language needs and communication needs of the chemistry students at master and ph.d. levels at the iranian universities. in this research, different methods were used including un-structured interview, structured interview, and two sets of question...

apart from other aspects, desert is a natural environment and is one of the appealing terrestrial elements. putting its symbolic and fictional senses aside, the term “desert” bears mystic sense more than material sense. in addition to the worlds materialistic experiences, desert has attracted the attention of writers because it creates a kind of inner experience, which returns the individual in...

esl/efl books play a crucial role in shaping language learners worldview of gender roles in society. the present study investigated the status of sexism in two sets of efl textbooks, one developed by non-native iranian authors (ili series) and the other by native authors (top notch series). first, two books from each series was selected randomly. then, a quantitative analysis was carried out wi...

anxiety is one common disorder during childhood. in curing anxiety disorders, there are different types of psychological remedies, pharmotherapy, family therapy, and music therapy that can improve the individual’s anxiety, but we need some other remedies to improve social and emotional relationship and interactions. considering the importance of curing the anxiety disorders, the effect of sand ...

flow in natural river bends is a complex and turbulent phenomenon which affects the scour and sedimentations and causes an irregular bed topography on the bed. for the reason, the flow hydralics and the parameters which affect the flow to be studied and understand. in this study the effect of bed and wall roughness using the software fluent discussed in a sharp 90-degree flume bend with 40.3cm ...