in this thesis,spin dependend transport and electron transport through of ng/sg(graphene/ superconductor graphen) are studied in the junction of ng/fgt/sg. due to andreev reflection conductance increases in the presence of superconductor graphene.also, by applying a voltage gate on a superconductor, fermi level shifts and the conductance is independent of ferromagnatic substrate. also, the cond...

in this investigation the effect of external field on the electron density of nanostructures of cds, cdse, cdte, gaas and polymeric structure of three, four, five and six units of cds as a kind of nanosolar cells has been studied theoretically. as modeling this system in nanodimension, molecular structures has used. specific properties of molecular structures permit us to consider different sym...

due to lack of knowledge management system in the organization of technical and vocational university of iran (tvuni) and losing good employees because of retirement and substitution causes huge amount of costs to replace the similar expertise. there is no any suitable system in the tvuni to store, to document, and to distribute knowledge. based on the university’s features such as it has diffe...

tourism , today as one of the ways to make money, create jobs , and social and political interactions is considered. this paper aims to examine the strengths and weaknesses of tourism development in mahmoud abad ( mazandaran ). the research method in this study is " descriptive - analytical " and to collection of data used field methods such as questionnaires and documentation - library. the sa...

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 . ...

among the low–dimensional allotropes of carbon, nanotubes and graphene have attracted very much attention from nano–science and nanotechnology specialists. they have been proposed as building blocks in nanometer device engineering. however, these structures are not defect–free. in this thesis, we focused on defective carbon nanotubes and graphene, and studied the effect of couple of very common...

peace and national security protection and ironic solving of international conflicts become the preliminary foundation of the united nations charter and had been considered as the main responsibilities of the security council, after world war ii and the establishment of united nations organization. therefore, the security council enables to analyze every kind of conflicts and challenges which ...

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...

abstract: the present thesis includes ; one preface and 11speeches , that each speech considered in different researches . the prefact part , studied grammer back ground , the first speech considered a brief description about grammatical credits . the second speech considered the different typs of sentences , from structure and meaning points of view . the third speech considered the verb es...

‏‎the community dynamics of aquatic coleoptera(insecta)in one of the spring-stream habitats of bammo national park in fars province called cheshmeh-ye-ghanbari is studied as a pilot project and model for acquaintance with and furthering the biodiversity studies on fauna of iran. sixteen species-populations out of nineteen of this community were already identified for their taxonomy and for thei...