Sharif Digital Repository

Tehran is one of the most polluted megacities in the world, and based on different studies, vehicular sources are responsible for most of the criteria pollutant emissions in this city. The number of vehicles on the streets has been increased drastically leading to growing amount of emission and this trend is continuing. In order to reduce the amount of vehicular emission, it is vital to investigate the factors affecting vehicles emission in this city. This could help to find efficient solutions to improve the situation. Hence, a low-cost methodology to estimate the vehicular emissions is developed. In this... 

Many real-world communication systems such as Internet, online social networks, and brain networks can be modeled as a complex network of interacting dynamical nodes. These networks have non-trivial topological features, i.e., features that do not occur in simple networks such as lattices or random networks. The tremendous growth of Internet and its applications in recent years has resulted in creation of large-scale complex networks involving tens or hundreds of millions of nodes and links. Thus, it may be impossible or costly to obtain a complete picture of these large networks, and sampling methods are essential for practical estimation of network properties. Therefore, in this thesis, we... 

The bis(cyclometalated) platinum(II) complexes of the type [Pt(ppy)(p′py)], in which ppy = p′py = 2-(p-tolyl)pyridine, 6; ppy = 2-(3-bromophenyl)pyridine, p′py = 2-(p-tolyl)pyridine, 7; ppy = 2-(2,4-difluorophenyl)pyridine, p′py = 2-(p-tolyl)pyridine, 8; ppy = 2-(2,4-difluorophenyl)pyridine, p′py = 2-(2,4-difluorophenyl)pyridine, 9, have been prepared from the reaction of the cyclometalated platinum(II) complex [Pt(ppy)Me(SMe2)] with one equiv p′py and one equiv B(C6F5)3. The structure of 6, 7 and 10 determined using X-ray crystallography in solid state. However NMR spectroscopy methods have been used for structural characterization of the complexes in solution phase. The bis(cyclometalated)... 

Hybridization of the vehicles is one of the main solutions for reducing the vehicles’ fuel consumption (FC) and emissions. Hybrid electric vehicles (HEVs) are one of the main groups of hybrid vehicles. In this type, an electric motor is employed to help the engine propel the vehicle. Other method which can be implemented to reduce the vehicle’s FC and emissions is to employ continuously variable transmission (CVT) as the vehicle power transmission. By using CVT, the engine will be able to operate in the rotational speed approximately independent of the vehicle speed, which leads to a reduction in the engine’ FC and emissions. One of the main concerns in the HEVs’ design is the layout of its... 

During the recent past, due to the increase of electrical energy demand and governmental resources constraints in producing additional capacity in generation, transmission and distribution, privatization and restructuring in electrical industry has been considered. In most of the countries, different parts of electrical industry like generation, transmission and distribution have been separated in order to create competition. Considering these changes, environmental issues, energy growth, investment of private equity in energy generation units and difficulties of transmission lines expansion, DG units have been used in power systems. Moreover, reduction in need of transmission and... 

The bis-cyclometalated platinum(II) complexes [Pt(ptpy)2], 3, and [Pt(fppy)2], 4, in which, ptpy = 2-(p-tolyl)pyridine and fppy = 2-(2,4-difluorophenyl)pyridine have been prepared. The reaction of 3 with one equiv [Au(PPh3)]+ (prepared from the reaction between AuCl(PPh3) and AgOTf) gave the heterobinuclear complex [Pt(ptpy)2Au(PPh3)].OTf, 5, by formation of a Pt→Au dative bond. The structure of all complexes were characterized using multinuclear NMR spectroscopy in solution phase and the structures of 4 and 5 determined using X-ray crystallography in solid state. The structure of heterobinuclear complex 5 shows an unusual Pt-Au bond that supported by Au-Cipso bond. The absorption and... 

Platinum(II) complex [Pt(Carb-PPh2)Cl] (1) (Carb-PPh2 = 1,8-bis(phosphino)-3,6-di-tert-butyl carbazole) was synthesized from the reaction of K2[PtCl4] salt with PNP carbazole-based pincer ligand, 1,8-bis(phosphino)-3,6-di-tert-butyl carbazole (c) and LiHMDS in a 1:2:1.1 molar ratio. The structure of 1 was characterized by X-ray crystallography in solid state, NMR spectroscopy, UV-Vis spectroscopy, and photoluminescence spectroscopy in solution state. Platinum(II) complex [Pt(Carb-PPh2)(C≡CPh)] (2) was prepared from the reaction of complex 1 with phenylacetylene with a 3:1 molar ratio in the presence of CuI as a catalyst and triethylamine. Complex 2 was identified by NMR spectroscopy, UV-Vis...