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 treatment of in completely formed pulpless teeth has presented considrable problems. these teeth have wide open apexes and the walls of the root canal diverge toward the apical tissues. mechanical preparation cannot be done in the normal manner beacause of the large initial size and the taper of apical part of the canal , a mechanical stop cannot be produced at the apex of the canal and , t...

deployable scissor type structures are composed of the so-called scissor-like elements (sles), which are connected to each other at an intermediate point through a pivotal connection and allow them to be folded into a compact bundle for storage or transport. several sles are connected to each other in order to form units with regular polygonal plan views. the sides and radii of the polygons are...

abstract nowadaysphotovoltaic solar cells (pvs) areacknowledged the fastest growing energy technology in the word, however, they only account for only fraction of current global renewable energy capacity. it isrecognized that this incomplete market penetration has been largely a result of the technology’sexcessive cost. so researchers are trying to find innovative, economic way with theaim of ...

the effect of learning strategies on the speaking ability of iranian students in the context of language institutes abstract language learning strategies are of the most important factors that help language learners to learn a foreign language and how they can deal with the four language skills specifically speaking skill effectively. acknowledging the great impact of learning strategies...

in chapter one we will describe definitions and preliminary results to provide the global context of our own results to be presented in detail in the subsequent chapters in chapter two we consider degree-one maps of the circle and we study their rotation set. our main result in this chapter says that if the map is topologically mixing then its rotation interval is nontrivial (that is, not reduc...

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 ...

we show that when both sources ( lepton flavor violation sources and cp-violating phases) are present, the electric dipole moment of the electron, $d_e$, receives a contribution from the phase of the trilinear $a$-term of staus, $phi_{a_ au}$. for $phi_{a_ au}=pi/2$, the value of $d_e$, depending on the ratios of the lfv mass elements, can range between zero and three orders of magnitude a...

according to cheng (1999), in recent esl/efl literature, asian (especially east asian) learners of english as a foreign/second language have been arguably reported as reticent and passive learners. the most common allegations are that these students are reluctant to participate in classroom discourse; they are unwilling to give responses; they do not ask questions; and they are passive and over...

this study was an attempt to investigate the effect of using c-test passages on the reading comprehension and incidental vocabulary learning of iranian intermediate efl learners. the participants were 60 male efl learners at kish mehr institute in garmsar. in fact, there were two groups, an experimental group and a comparison group with 30 students in each. the participants were pretested throu...