in this work, a novel and fast method for direct analysis of volatile compounds (davc) of medicinal plants has been developed by holding a filament from different parts of a plant in the gc injection port. the extraction and analysis of volatile components of a small amount of plant were carried out in one-step without any sample preparation. after optimization of temperature, extraction time a...

abstract recent studies suggest that prelistening activities play an important role in the development of listening comprehension (e.g. long 1990;chiang and dunkel 1992; schmidt-rinehart 1994; jensen and hansen 1995; robinson et al., 1995; buck, 1995; foster and skehan,1996; teng 1996; robinson, 2001; chang and read 2006). in line with previous studies and to shed light on a new aspect of sche...

the present study was conducted to investigate the effect of implicit focus on form through input flooding and the effect of noticing, explicit focus on form on linguistic accuracy. to fulfill the purpose of the study, 86 iranian pre-intermediate efl learners of one of the language institutes were chosen by means of administering ket as the homogeneity test. these learners were pretested throug...

this study compared the different effects of form-focused guided planning vs. meaning-focused guided planning on iranian pre-intermediate students’ task performance. the study lasted for three weeks and concentrated on eight english structures. forty five pre-intermediate iranian students were randomly assigned to three groups of guided planning focus-on-form group (gpfg), guided planning focus...

one very decisive factor in students’ academic destiny is the result they get at final term examinations. because of its importance, both students and teachers are curiously anxious about them. as normally it is the case, these final term tests are prepared hurriedly in short time by teachers which result in students’ dissatisfaction, complaining on how the test was different from their expecta...

there are two major theories of measurement in psychometrics: classical test theory (ctt) and item-response theory (irt). despite its widespread and long use, ctt has a number of shortcomings, which make it problematic to be used for practical and theoretical purposes. irt tries to solve these shortcomings, and provide better and more dependable answers. one of the applications of irt is the as...

abstract the present study was conducted in order to investigate the impact of an integrated model of form-focused and task-based instruction on iranian efl learners vocabulary learning and retention.it also aimed to detect efl learners attitude towards the implementation of form-focused task-based vocabulary instruction in the classroom. in order to address the purposes of this study, a sampl...

we describe here a suitable approach for the synthesis of n-unsubstituted monocyclic b-lactams under mild reaction conditions by the annelation of imines with substituted acetylchlorides. in this method the reaily available phtalimidoacetyl chloride were allowed to react with - dibenzylideneiminotoluene (hydrobenzamide) in the presence of an equimolar amount of triethylamine in refluxing toluen...

teachers beliefs have usually been left unattended in the realm of educational research in iranian context. one of those beliefs which seems to impact teachers performance in the classroom is their sense of self-efficacy, which refers to teachers belief in their ability to enhance student achievement and in bringing about positive learning outcomes. the present study aimed to investigate the pr...

abstract u.s. attack to afghanistan after 9/11 provided opportunities for us who tried to become the dominant power after collapse of ussr and bipolar world. thinkers like fukuyama believed american liberal democrats thought would be universally accepted without resistances. liberal democracy is the best and final model of governance; in this regard, united state has moral responsibilities for...