let g=(v,e) be a graph with vertex set v and edge set e.for two vertices u,v of g ,the closed interval i[u,v] ,consists of u,v and all vertices lying in some u-v geodesic in g.if s is a set of vertices of g then i[s]is the union of all sets i[u,v]for u,v ? s. if i[s]=v(g) , then s is a geodetic set for g.the geodetic number g(g) is the minimum cardinality of geodetic set.the maximum cardinalit...

this work is presented in five parts. in the first part preparation of the starting complex [pt(c^n)cl(dmso)], 1, in which c^n = n(1),c(2?)-chelated, deprotonated 2-phenylpyridine, and dmso = dimethylsulfoxide, and its reaction with 1 equiv of the biphosphine ligands bis(diphenylphosphino)amine, dppa, or bis(diphenylphosphino)methane, dppm, to give the complex [pt(c^n)cl(dppa)], 2, or [pt(c^n)c...

در این پایان نامه ابتدا شرط برد پایدار $ n $ را معرفی کرده، سپس حلقه های تبادلی را تعریف می کنیم و شرایط لازم و کافی برای این که حلقه تبادلی $ r $، در شرط برد پایدار $ n $ صدق کند را بیان می کنیم. نشان می دهیم که حلقه تبادلی $ r $، در شرط برد پایدار $ n $ صدق می کند اگر و تنها اگر برای هرعنصر منظم $ ain r ^{n} $، عنصر تک پیمانه ای مانند $ u in r ^{n} $ وجود داشته باشد به طوری که $ au in r $ یک ...

with the increasing population and the need for more food, as well as with the development of science and technology, human approach to unnatural and often chemical inputs to increase agricultural production has been a great expansion and problems such as increased cancers, chronic diseases has created environmental pollution. implementation of organic organic is a solution to these problems . ...

in this thesis, a better reaction conditions for the synthesis of spirobarbiturates catalyzed by task-specific ionic liquid (2-hydroxy-n-(2-hydroxyethyl)-n,n-dimethylethanaminium formate), calcium hypochlorite ca(ocl)2 or n-bromosuccinimide (nbs) in the presence of water at room temperature by ultrasonic technique is provided. the design and synthesis of spirocycles is a challenging task becaus...

in reality, most structures involved in geotechnical engineering are three dimensional in nature, and although in many, plane strain or axisymmetric approximations are reasonable, there are some, for which 3-d treatment is required. the quantity of data, and the size of the various vectors and matrices involved in such analysis, increase dramatically. this has sever implications for computer r...

within communicative, interactive, and learner-centered framework of language teaching and learning, students need to learn four skills of listening, speaking, reading, and writing for their educational success. but of all the language skills, reading enjoys a paramount significance in so many second or foreign language academic contexts. in spite of its importance, language learners still have...

textbooks play a crucial role in language learning classrooms. the problem is that among the great quantity of available textbooks on the market which one is appropriate for a specific classroom and a group of learners. in order to evaluate elt textbooks, theorists and writers have offered different kinds of evaluative frameworks based on a number of principles and criteria. this study evaluate...

the primary goal of the current project was to examine the effect of three different treatments, namely, models with explicit instruction, models with implicit instruction, and models alone on differences between the three groups of subjects in the use of the elements of argument structures in terms of toulmins (2003) model (i.e., claim, data, counterargument claim, counterargument data, rebutt...

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...