objective: the objective of this study was to investigate the invitro fluoride release of four new self-adhesive resin cements; set (sdi, australia), breeze (pentron, usa), embrace wetbond (pulpdent, usa), g-cem (gc, japan) and to assess the bonding performance of these self-adhesive resin cements for bonding of orthodontic brackets. materials and methods: for fluoride release experiment, six ...

writing as a productive skill requires practice in the basic sub-skills of vocabulary and grammar. in fact, grammar has been viewed as the core of programs in writing classes to help the students put the elements of sentence together and combine sentences of specific lengths to come up with an error-free work of art. conceptualizing l2 writing in this way introduces writing as a product and enc...

the quest for power has formed much of the world history especially in 20th and 21st centuries. oil (energy) particularly after industrial revolution has been a tool for conquest and power and has been transformed to a geopolitical issue. from a geopolitical point of view this has been the case for the last two centuries in central asia and caucasus. central asia and caucasus has always been...

‎in this article‎, ‎we have focused one some basic and productive information about the properties of spectrum and singular values related to compact operators which are ideals in a c*-algebra of bounded operators‎. ‎considering a two-sided connection between the family of symmetric gauge functions on sequence of singular values of compact operators and symmetric norms on finite dimensional ope...

this experimental study has been conducted to test the effect of oral presentation on the development of l2 learners grammar. but this oral presentation is not merely a deductive instruction of grammatical points, in this presentation two hypotheses of krashen (input and low filter hypotheses), stevicks viewpoints on grammar explanation and correction and widdowsons opinion on limited use of l1...

with the introduction of communicative language teaching, a large number of studies have concerned with students’ oral participation in language classrooms. although the importance of classroom participation is evident, some language learners are unwilling to engage in oral activities. this passivity and unwillingness to participate in language classroom discussions is known as “reticence”. rev...

چکیده مجموعه حاضر با هدف معرفی و ارائه ی توصیفی برای اصطلاحات رایج در دانش معنی شناسی تهیه شده است. برای دستیابی به چنین هدفی سعی بر آن بود تا صرفاً به واژگان نقش مند در شاخه ی عمده ی معنی شناسی زبانی توجه شود. در حوزه معنی شناسی زبانی، به اصطلاحات در شاخه ای از این دانش، یعنی معنی شناسی نظری (theoretical semantics) و آنچه معنی شناسی کاربردی (applied semantics) نامیده ایم، اشاره شود. و هدف از ت...

adolescents and young adults and their problems is an issue whose importance is obvious to anyone because youth are the founders of our countrys future and requires proper planning to be on leisure. given the importance of leisure,this study to investigate needs assessment and planning how adolescents and young adults spend their leisure time in urban of case study of high school girls and boys...

abstract in aggregate, active forms of reactive silica with mineral names are sometimes associated with sand and gravel in concrete mixture. alkali hydroxides originated from alkalis in the cement or other resources form an alkaline silica gel with this reactive silica which becomes swallowed and expanded during time causing damage to concrete. there have been growing researches on alkaline r...

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...