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...

abstract: mineral scaling in oil and gas production equipment is one of the most important problem that occurs while water injection and it has been recognized to be a major operational problem. the incompatibility between injected and formation waters may result in inorganic scale precipitation in the equipment and reservoir and then reduction of oil production rate and water injection rate. ...

in this thesis protic and aprotic ammonium-based ionic liquids were synthesized and their surface tensions were measured in the range of 298-373k. the protics are alkyl ammonium-based ils with the carboxylate (formate, acetate, propionate) anion and aprotics are quaternary ammonium-based ils with bis(trifluoromethylsulfonyl)imide anion. capillary rise method was used for surface tension measure...

هدف این پایان نامه تعیین تعداد مولدهای مینیمال ایده آلها در یک حلقه (جابجایی، یکدار، موضعی و نوتری) است، هر چند تعیین دقیق تعداد مولدها در حالتهایی خاص امکان پذیر است اما در حالتهای کلی روش های موجود بدست آوردن کرانهای مختلف برای تعداد مولدها است. مرجع اصلی این پایانامه ‏‎[1]‎‏ می باشد، به علاوه از نتایج جدیدی که در مرجع ‏‎‏‎[2]‎‏ نیز آمده استفاده کرده ایم. ‏‎[1]. j. sally. numbers of generator...

most specialists in the field of foreign language teachingconsiderreading skill as an interactive process between the reader’s prior knowledge and the text.accordingly, the activation of prior knowledge for an effective comprehension is very important. it is generally agreed that the pre-reading phase is the stage where this type of interaction and activation may be enhanced throughcertain stra...

abstract poor reading comprehension can result in failure in using references, benefiting from professional gatherings and resources, keeping up with the growing body of knowledge in the virtual world of the internet, and failing to achieve in efl programs. the purpose of the present quasi-experimental study was to explore the effects of background knowledge and previewing narrative and expos...

learning-oriented assessment seeks to emphasise that a fundamental purpose of assessment should be to promote learning. it mirrors formative assessment and assessment for learning processes. it can be defined as actions undertaken by teachers and / or students, which provide feedback for the improvement of teaching and learning. it also contrasts with equally important measurement-focused appro...

on this project we try to calculated power of hydrogen on dycarbonil compound in different ways ; the first way is shoster way , for sain power of hydrogen notice the different power between central conforms on it and main conform that’s didn’t have hydrogen joint . or in other way different of energy between open and close form. second way, is average way? this is for way that studied conf...

drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...