abstract the present study was conducted to examine the effect of proficiency on students interaction while carrying out the grammar-based task(s) in collaboration. in particular, the study examines whether the level of proficiency affects the learners’ focus of attention to grammatical and lexical features. the study takes a further step and examines whether there is any difference in the use...

we have two part in this thesis, at first: the interaction of native calf thymus dna (ct-dna) with two anthraquinones including quinizarin (1,4- dihydroxy anthraquinone) and danthron (1,8- dihydroxy anthraquinone) in a mixture of 0.04 m brittone-robinson buffer and 50% of ethanol were studied at physiological ph by uv-vis absorption, florescence, circular dichroism spectroscopic methods, viscos...

employees always concern about losing their job , or in other word , losing their income resources. for this purpose, every government requires strong system for covering these concerns. the unemployment insurance (ui) program’s can be used for achieving this goal. in this thesis, we price ui based on the insurance history of employee and the duration of being unemployed. we use the weibull dis...

abstract: in the paper of black and scholes (1973) a closed form solution for the price of a european option is derived . as extension to the black and scholes model with constant volatility, option pricing model with time varying volatility have been suggested within the frame work of generalized autoregressive conditional heteroskedasticity (garch) . these processes can explain a number of em...

abstract compound is a word-formation process that are made two free morpheme (independent) and forms a new word with a new meaning that consists of meaning of both two component of compound. avestan language is one of the ancient iranian languages that is one of the indo-iranian languages. indo-iranian languages is one branch of indo-european languages. structure of compound noun and adjectiv...

abstract: in this thesis, we focus to class of convex optimization problem whose objective function is given as a linear function and a convex function of a linear transformation of the decision variables and whose feasible region is a polytope. we show that there exists an optimal solution to this class of problems on a face of the constraint polytope of feasible region. based on this, we dev...

in the first part of this thesis we explored wetting and its dynamics for small droplets. first, we showed how a simple feature of water droplets on a surface, i.e. laplace pressure, can be exploited to build a micropump. we investigated capillary pumping in microchannels both experimentally and numerically. putting two droplets of different sizes at the in/outlet of a microchannel, will ge...

based on the latest records of typhlops vermicularis merrem, 1820 from iran, this species is distributed in the northern and southern regions of the country. in this study, new records of typhlops vermicularis are presented and it is shown that distribution range of this species is extended towards the eastern and western iran, and according to the new distribution map, it can be assumed that t...

it is definitely necessary to understand the concept and behavior of causation of life insurance policies and its determinants for insurance managers, regulators, and customers. for insurance managers, the profitability and liquidity of insurers can be increasingly influenced by the number of causation through costs, adverse selection, and cash surrender values. therefore, causation is a materi...

in chapter one we will describe definitions and preliminary results to provide the global context of our own results to be presented in detail in the subsequent chapters in chapter two we consider degree-one maps of the circle and we study their rotation set. our main result in this chapter says that if the map is topologically mixing then its rotation interval is nontrivial (that is, not reduc...