Sharif Digital Repository

The main goal of current investigation was partial reduction of Fe2O3 available in Hematite-rich ore to Magnetite by Fludization Bed method. The reductive gas, CO, was produced by incomplete combustion of Acetylene and Airmixed in inappropriate ratio. X-Ray Diffraction and X-Ray Florescence analyses were implemented in order to conducting qualitative analysis of present phases before and after reduction of the ore. Quantitative analysis of the same phases was also conducted by Titration. The latter analysis revealed the precise magnitude of available iron in each of the oxide containing phases. The chemical composition of the reactor gas was also determined before and after reduction... 

Urbanization increases impervious surfaces and therefore reduces land permeability. As a result, higher amount of runoff is produced which leads to environmental degradation and economic loss. Use of pervious/permeable pavements is an efficient approach to reduce runoff volume and improve the quality. In this study, different design methods of pervious/permeable surface are first described using structural and hydrological modules. Then, a software program for pervious/permeable surface design is put forth. Supported by various available design methods (focusing on pervious surfaces in Iran), the software employs structural, hydrological, economic (cost estimation) and qualitative... 

Complex networks represent a wide diversity of systems in nature and human interactions. Networks are graphs that describe the structures of interacting systems and give significant information about the patterns of connections between the nodes in a particular system. In turn, having knowledge about the structure of networks and their arrangements enables one to make certain types of predictions about their behavior of network.Network methods have had profound influence in many domains and fields in the past decade. Centrality measures are very important tool for analysis complex networks, in real-world complex networks are heterogeneous structures, all their components such as nodes... 

Since 2005, processor designers have increased core counts to exploit Moore’s Law scaling, rather than focusing on single-core performance. For decades, this approach provides desired performance for parallel and multithreaded workloads. On the other hand, rising of utilization wall limits the number of transistors that can be powered on in chip and result in a large region to be dark. So, same as before trend for performance scaling in future multi processor, an appropriate architecture is essential. There are some structures for this era which used specialization approach to cope with the limited power budget. Therefore, in this thesis, we propose a general-purpose platform that provides... 

The Mashhad plain is one of the most important plains in Khorasan-e-Razavi province. In the last decades, rapid population growth coupled with agricultural expansion has tremendously increases pressure on the groundwater resources. Large increases in water demands with little recharge have strained the plain groundwater resources resulting in declines in water level in last decades. Due to declining of groundwater level, digging new wells has been forbidden since 1965. In this thesis, users in agricultural, municipals and industrial sections have been modeled with Multi-Agent System, and results of their water extraction on groundwater level have been modeled with GMS. There are two... 

Distribution is a necessary part of a supply chain. Location-routing problem is a problem that decide about location of facility , allocation and routing for vehicle. This research focus on modeling for multi-level and multi-product for perishable foods that include five suppliers, three plants, two depots and ten costumers. costumers and products classify according to their importance for the company and their quality into three batch. In order to decreasing of cost return orders and damaged products, a special system are Designed that products can be sent again. In real world we do not have any certain data for model’ parameters, then we consider uncertainty and use robust for showing... 

The unique properties of phase change materials (PCMs), such as high latent heat and nearly constant phase change temperature, have made them a suitable option for use in thermal energy storage systems and thermal management systems. However, the low thermal conductivity of these materials has imposed limitations on their widespread use in industries. In this study, for the first time, the effect of injecting a boiling fluid (BF) into the PCM container to enhance heat transfer and accelerate the solidification process has been experimentally investigated. In this regard, paraffin wax and acetone have been selected as the PCM and the BF, and the effects of parameters such as the initial... 

Since physical variables are almost dependent, uncertain and have significant time and spatial changes, nature of hydrological and environmental systems is so complicated, nonlinear and dynamic. Many models have been developed for studying and analyzing various phenomena in these systems. Recently data mining approaches have been used as new methods for modeling of complicated engineering systems. In this study, performance of several data mining tools in analyzing two phenomena in water quality management have been evaluated. These algorithms are Multilayer Perceptron Neural Network (MLP), Radial Basis Function Neural Network (RBFN), Support Vector Machines (SVMs) in the field of Artificial... 

study has been divided into two main sections. In the first section, six climate variables have been analyzed in 15 synoptic stations in Iran’s west region through parametric and non-parametric statistical tests in order to find the climate varibility. The results illustared that, in general, there is no climate variability in the western part of Iran. Investigation of climatic indices and changes in the meteorological data in the entire study area (including a large portion of Middle East), in a 30 year period (1979-2008), is eloquent of a drought during the last 10 years of the period. In the second section, by means of the Aerosoal Index (AI) extracted from TOMS and OMI tools, it was... 

In recent decades, local, regional and national research programs have discovered stormwater runoff as the principal cause of water pollution in most urban areas. To solve urban stormwater runoff problems, we should use revisory measures. This is possible by using Best Management Practices (BMPs). BMPs are innovative technologies to reduce the movement of pollutants from land into surface or groundwaters, in order to protect water quality within natural and economic limitations.Three types of BMPs are discussed in this study; swale, bioretention systems and pond. They have different installation requirements, costs and pollutant removal efficiency. The main objective of this research is to... 

Urbanization and increase in impervious areas owing to building construction, pavements of streets, parking lots and sidewalks, amount of surface runoff in cities has been rose. One of the environmental problems of Tehran during the rainfall is the high polluted runoff flowing in the city and eventually transfers pollution to aquifers. So in order to decline the consequences of this polluted surface runoff, it is crucial to understand how the runoff and pollution form. One way of decreasing pollution in runoff is hiring swales attenuation potential. In this study, problems associated with runoff, particularly in relation to the formation, transformation and removal of pollutants from runoff... 

Increasing aviation share in air pollution, population growth, scarcity of available resources such as land (airport), airspace and energy along with uncertainties in air transportation demand and energy market, has motivated the industry stakeholders to push researches toward sustainable models in fleet planning and design. In this thesis we have investigated the suitability of a decision-making model for airline fleet management, based on “Game Theory” and the idea of commercial formation flight (COFOFS). We intend to examine the circumstances under which, an airline needs to substitute a wide-body aircraft with number of smaller ones, while employing the approach of formation flight.... 

Lake Urmia is the largest inland lake of Iran and one of the most important water ecosystems in Iran and the world. The ecosystem of this lake is a typical example of a closed drainage basin into which all the runoff flows in the rivers of the basin are discharged. Because of its unique natural and ecological features, Urmia Lake has been declared as a national park since 1346, along with Kabudan and Qion Daghi islands, among the protected areas. Among the most important invertebrates in the lake, we can mention Artemia, which is a species of saltwater shrimp and one of the native species of Lake Urmia. This species is the most important source of food for many water birds such as flamingos.... 

The challenges of urbanization have been the focus of researchers since the past. With the expansion of urbanization and massive migration of people from villages to cities, these challenges became more important in our country. These issues, which exist in many other countries in a serious manner, are discussed in the branch of urban economy in the world. This thesis is arranged in three chapters, in each of which one of the aspects related to urban economy and housing is discussed. In the first chapter, the effects of the construction of Mehr housing on the value of nearby residential properties are investigated using difference-in-difference method. It is shown that the construction of... 

In this thesis the behavior of a 3D wing has investigated by Flow visualization and pressure acquisition test. The goal of this tests was considering changes in 3D wing section parameter in comparison with 2D airfoils. The performed Tests showed that variation in 3D wing treatment is affected by finite aspect ratio and sweep angle and also indicate changes in pressure profile, increasing pressure peak and decreasing effective speed. CFD studies has conducted to investigate special effect of sweep angle and show that lift and drag coefficient decrease with increasing sweep angle. Also different section pressure profile near the wing tip and intersection of wing/fuselage varies and miss... 

Groundwater resources are considered as important resources of fresh water specifically in arid and semi-arid regions like Iran. Urmia Lake (UL) basin is one of these regions where groundwater resources play an important role in supplying water and due to inappropriate water resources management during the last two decades it has faced serious problems, like declination of water level in UL. Groundwater and surface water form an integrated system in the UL basin and have a mutual effect on each other. Hence, any improvement in exploitation of aquifers in that region could benefit UL water demand management. Appropriate water resources management in Miandoab plain which transfer almost 50... 

Due to water resources restriction and increase in water demand, optimum use of existing available resources is more essential. This needs accurate prediction of streamflow with lag time from one to several months. In recent decades identification of long term climate variables as predictors of hydrological process has made considerable evolution in climatic predictions and several studies have been made in this field. In this research streamflow volume of Dez Dam in dry season (April to August) has been predicted by using multiple regression models and considering seasonal rainfall data, climate indices and ocean-atmospheric variables including surface temperature of adjacent seas and...