fluorescence chemical sensors for the highly sensitive and selective determination of pb2+ , hg2+, co2+ and fe3+ ions in aqueous solutions are described. the ion sensing system was prepared by incorporating lipophilic ligand (l) as a neutral ion-selective fluoroionophore in the plasticized pvc membrane containing sodium tetraphenylborate or potasium tetrakis (p-chlorophenyl) borate as a liphoph...

building on previous studies on intellectual features and learners’ grammar learning, the present study aimed at investigating whether intelligence criterion had any impact on efl learners’ english grammar learning across two intelligence levels. in the current study, the participants were divided into two experimental and control groups by administration of raven i.q. test. this led to the for...

this study examines the effetivenss of task-based activities in helping students learn english language structures for a better communication. initially, a michigan test was administered to the two groups of 52 students majoring in english at the allameh ghotb -e- ravandi university to ensure their homogeneity. the students scores on the grammar part of this test were also regarded as their pre...

abstract part one: the electrode oxidation potentials of a series of eighteen n-hydroxy compounds in aqueous solution were calculated based on a proper thermodynamic cycle. the dft method at the level of b3lyp-6-31g(d,p) was used to calculate the gas-phase free energy differences ,and the polarizable continuum model (pcm) was applied to describe the solvent and its interaction with n-hydroxy ...

for several years, researchers in familiarity of efl teachers with post-method and its role in second and foreign language learners’ productions have pointed out that the opportunity to plan for a task generally develops language learners’ development (ellis, 2005). it is important to mention that the critical varies in language teaching was shown is the disappearances of the concept of method ...

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...

چکیده کنه تارتن دو لکه ای tetranychus urticae koch یکی از چندخوارترین آفات شناخته شده محصولات کشاورزی دنیا به حساب می آید. در این بررسی جمعیت تخم و مراحل فعال این کنه در شرایط آلودگی طبیعی و مصنوعی در برگ های 8 رقم لوبیا در سال 1392 در گلخانه و مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه ارومیه موردمطالعه قرار گرفت. آزمایش به صورت طرح کاملاً تصادفی برای شرایط مزرعه در10 تکرار و برای شرایط گلخانه ای...

this thesis is presented 10 ghz voltage controlled ring oscillator for high speed application. the voltage controlled ring oscillator was designed and fabricated in 0.13یm cmos technology. the oscillator is 7-stages ring oscillator with one inverter replaced by nand-gate for shutting down in the ring oscillator during idle mode. tri-state inverter was used to control of 126 bit vector in ri...

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...

the purpose of this study is to investigate and explore the causes of identity crisis as one of the debilitating consequences of colonial project after the withdrawal of colonial power. in order to do justice to the full-length severity of displacement that was the fruit of indentureship, v. s. naipauls west indian epic, a house for mr biswas, has been scrutinized with the main focus being the ...