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...

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 ...

abstract in first part of this project, the use of a new and biguanid-like catalyst supported on silica as a recyclable catalyst provides a new route for the synthesis of a variety of arylalkylidene rhodanine derivatives through knoevenagle reaction in at present of solvent at room temperature. rhodanine derivatives and especially arylalkylidene rhodanines have proven to be attractive compound...

dendrimer synthesis strategies now provide virtual control of macromolecular nanostructures as a function of size and surface/interior functionality. these strategies involve the covalent assembly of hierarchical components reactive monomers , branch cells or dendron’s around atomic or molecular cores according to divergent/convergent dendrite branching principles.combinon of two or more dendri...

the purpose of this study is identifying effective factors which make customers shop online in iran and investigating the importance of discovered factors in online customers’ decision. in the identifying phase, to discover the factors affecting online shopping behavior of customers in iran, the derived reference model summarizing antecedents of online shopping proposed by change et al. was us...

attempts have been made to study the thermodynamic behavior of 1,3 butadiene purification columns with the aim of retrofitting those columns to more energy efficient separation schemes. 1,3 butadiene is purified in two columns in series through being separated from methyl acetylene and 1,2 butadiene in the first and second column respectively. comparisons have been made among different therm...

Application of conceptual hydrological models is an important issue in watersheds for researchers, especially in arid and semi-arid regions. The hydrological behaviors are complicated in such watersheds and their calibration is more difficult. In this article, the conceptual and semi-distributed SWAT model is used for a semi-arid Nishabour watershed with 9350 km2 area. Streamflow simulation is ...