in this thesis our aim is to construct vector field in r3 for which the corresponding one-dimensional maps have certain discontinuities. two kinds of vector fields are considered, the first the lorenz vector field, and the second originally introced here. the latter have chaotic behavior and motivate a class of one-parameter families of maps which have positive lyapunov exponents for an open in...

1.0 overview it seems that grammar plays a crucial role in the area of second and foreign language learning and widely has been acknowledged in grammar research. in other words, teaching grammar is an issue which has attracted much attention to itself, and a lot of teachers argue about the existence of grammar in language teaching and learning. this issue will remind us a famous sentence f...

according to coates’s (2004, as cited in zhang, 2010) definition of "conversational dominance" (p.111), it refers to the phenomenon of a speaker dominating others in interaction. specifically, it means how a speaker makes use of certain strategies to get the floor and maintain the floor. thus, the amount of talk is the main measurement for the dominance of the conversation. whether a speaker do...

this study focuses on tracing the clearly defined elements of magic realism in toni morrison’s song of solomon as an illustrious african american example of the mode. magic realism is a fictional technique that combines fantasy with raw physical reality in a search for truth beyond that available from the surface of everyday life. toni morrison, as a distinguished african-american practitioner ...

nowadays, air pollution is a global problem that has had significant growth by technology development, population growth andindustrial development. industrial development brought natural resources deterioration, more manufacturing products, and more environmental pollutants. if pollutant won’t be controlled, human-being and wildlife will face the critical risks. significant release and critical...

in this thesis, a new optically active poly(amide-imide) (pai) was synthesized by the indirect polycondensation reaction of the l-phenylalanine based diacid chloride and 4,4?-diaminodiphenylether in the presence of triethylamine in n-methyl-2-pyrrolidone. the formation of pai was confirmed by ftir, 1h nmr and elemental analysis. in next step, the surface of titanium dioxide (tio2) nanoparticles...

abstract since heubners (1985) pioneering study, there have been many studies on (mis) use/ non-use of articles by l2 learners from article-less and article languages. the present study investigated how persian l2 learners of english produce and interpret english definite descriptions and demonstrative descriptions. it was assumed that definite and demonstrative descriptions share the same cen...

abstract there is not much sources about ancient carnival and ceremonies , but some information can be gain from documents . as a matter of fact the ceremonies were a part of zarartiyan principles which zartosht had taken them to his religion . it should be mentioned that the oldest ceremonies are about poster and agriculture principles this seasonal ceremonies were very important for agri...

this thesis examines the significances and implications of inflicted physical pain in waiting for the barbarians (1980) by john maxwell coetzee (1940 - ). the researcher tries to show how body becomes a site for exercising violence. in this way, the government’s representatives turn bodies of the barbarians into blank pages through torturing in order to create the truth of the empire. in this p...

efl/esl textbooks have been regarded as essential language teaching materials with which the learners spend about 70 up to 90 percent of their class time. the important role they play and their vast use make them not only influential in learning the language but also in shaping values and attitudes. put it another way, textbooks socialize learners using their contents (i.e. texts, illustrations...