Sharif Digital Repository

The proper design of the urban infrastructure is crucial to develop civilization in a developing area. While there are dozens of managerial suggestions to go along with the static aspects of components in urban infrastructure design, hardly any piece of advice may be found to ensure dynamic outcomes of the whole design in advance. In this paper, a novel system dynamics model is introduced and applied in this context as a contribution to fill the research gap. The modular nature of the model development helps to alleviate the challenge of simultaneous design of components and system, with the potential capability of both static and dynamic verification. It allows the decision aider to observe... 

Ways to reduce an airline's cost has been studied for years. In fact, in order to achieve this goal, ones need to know different types of airline's costs including; fuel and oil, maintenance, Ticketing, passenger services, etc. and their impact on the total cost of an airline. According to announcement of ICAO [1], "maintenance cost (about 11% of total cost) is the second major cost after fuel and oil". Therefore, this may attract airline owners' attention to find ways to control maintenance cost and eventually the total cost of an airline. Though, there are many systematic approaches to analyze cost reduction and making policies, in this article, SD modeling is applied to develop a... 

The properties of metallic nanorods vary due to changes in their composition, size and shape, which all depend on the aspect ratio of the nanorods. This work focuses on the optimization of the aspect ratio of silver nanorods using response surface methodology (RSM). Seed-mediated approach, which is the newest method with less difficulty, has been used for the synthesis of silver nanorods. First, silver ions were reduced with sodium borohydride in the presence of sodium citrate dehydrate, as stabilizer. Then, the prepared seeds were added to a solution containing more metal salts, a weak reducing agent (ascorbic acid) and a rod-like micellar template (cetyltrimethylammonium bromide, CTAB)....