the effect of the presence of perforations on he stresses of a plate is a problem which is of great interest in structural design and in the mathemattical theory of elasticity. among the many hole patterns that are likely to require consideration is the ring of equally spaced circular holes. the present worke investigates stress & strain analysis of a thin isotropic circular plate containing a ...

today the image of a permanent skeletal space of cities affected by some forces or mechanisms is put in time with social-economic development and while imposes a new face and perspective to physical anatomy of cities, and prepares field to changes in content and social- economic structures of cities too. simultaneously with quitting villages in order to settle in cities by villagers, the phen...

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...

the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...

the purpose of this thesis was to investigate how differently metacognitive, cognitive, and social/affective strategies affect l2 learners’ reading comprehension. to this end, the study employed a quasi-experimental design with a placement test as a proficiency test to find the homogeneity of groups. three classes were randomly selected as the experimental groups (n =90), and each class was tau...

the frame semantic theory is a nascent approach in the area of translation studies which goes beyond the linguistic barriers and helps us to incorporate cognitive and cultural factors to the study of translation. based on rojos analytical model (2002b), which centered in the frames or knowledge structures activated in the text, the present research explores the various translation problems that...

in this thesis, we consider a mathematical model of cancer with completely unknown parameters. we study the stability of critical points which are biologically admissible. then we consider a control on the system and introduce situations at which solutions are attracted to critical points and so the cancer disease has auto healing. the lyapunov stability method is used for estimating the un...

abstract tasks nowadays are at the center of attention in sla research. task types is one of the critical issues in this regard, their effectiveness and suitability to any particular context, their characteristics and the result they yield are among some of these issues. on the other hand, discourse markers (dms) have been very much investigated and their effectiveness in conveying the meaning...

in this project, some new polyaspartimides, (pas)s, have been synthesized form michael addition reaction between new synthetic bismaleimide (bmi) and some aromatic diamines. a characteristic property of this polyaspartimides is a pendent carboxylic group, which introduced to these polymers from new bismaleimide. bismaleimides (bmi) is one of the interesting compounds, which can be self-polymeri...

over the past decades a number of approaches have been applied for forecasting mortality. in 1992, a new method for long-run forecast of the level and age pattern of mortality was published by lee and carter. this method was welcomed by many authors so it was extended through a wider class of generalized, parametric and nonlinear model. this model represents one of the most influential recent d...