Sharif Digital Repository

Cement as a major industrial product plays an important role in the growth and development of countries. However, the economic condition in Iran has led to a decline of the production of this strategic product in recent years. At the moment, most of cement factories are faced with overproduction and inefficiency due to high production cost, broken financial situations, high energy cost, wages and overhead cost that have led to a serious crisis in cement industry. Scientific research must be carried out to find solutions to the present critical situation in the cement industry. The application of Lean Management System leads to a sustainable development of cement industry.In this study, a... 

Telework is an adaptable method for working which covers an extensive variety of work exercises in circulated associations comprised of people with robots and independent frameworks. From the levels of Nano and micro frameworks and gadgets the distance to the level of worldwide undertaking systems, beneficial work is reshaped by E-Work or Telework or Telecommute. The current work stresses on the part of learning administration as an empowering influence of E-Working standard. The four primary circles of information in e-Work related are: ‘‘e-Work”, ‘‘Integration , Coordination and Collaboration”, ‘‘Distributed Decision Support” and ‘‘Active Middleware”. Cloud computing can be distinguished... 

Competitive world of industrial production need more speed and faster reaction for the customer needs. This should be carried out in low cost activities while satisfying what the consumers and customers require. Business of commercial refrigerators and freezers is a big industry targeting small to big customers. In this thesis a systematic method relying on reduction of cost, reworking and unexpected expenditures in product life is utilized. Stands for Design for Manufacturing, DFM is a series of principles and guideline simply to achieve a faultless design of a product so that the non-incurred costs of the product travel through its life cycle become minimized. Freezers and refrigerators... 

E-Work is defined as collaborative, communication-enabled and computer-supported productive activities in distributed organizations consist of humans with robots and autonomous systems. From the levels of nano and micro systems and devices all the way to the level of global enterprise networks, productive work is reshaped by e-Work. The current literature emphasizes on the role of Knowledge management as an enabler of E-Working paradigm. The four main circles of knowledge in e-Work related are: ‘‘e-Work”, ‘‘Integration Coordination and Collaboration”, ‘‘Distributed Decision Support” and ‘‘Active Middleware”. It has been generally recognized that computer and communication science and... 

This research investigates and optimizes solvent extraction parameters for separat1ing thorium from the leach solution of the uranium-bearing ore at the ChahGaz mine. The study is applied research aimed at achieving technical knowledge of thorium extraction and purification from thorium-bearing ore through hydrometallurgical processes to obtain thorium concentrate and provide laboratory and semi-industrial flotation. The results obtained from this project lead to the production of thorium concentrate, which can later be utilized in industrial-scale applications. In this project, the influential parameters in the solvent extraction process were simultaneously examined through experimental... 

Molybdenum is one of the important elements of the intermediary metal with atomic number 42, which is used in various industries, but among the important uses of this metal in the nuclear industry, we can mention the presence of this element in the production of yellow cake as an impurity and also as a precursor for the production of radiopharmaceuticals. It is one of the impurities that remain in all stages of yellow cake production along with uranium, and the high presence of this element causes the centrifuges to become unbalanced during the injection of "U" "F" _"6" gas, and on the other hand, technetium, the main ingredient in the production of radiopharmaceuticals, It comes from the... 

Today, the pollution of heavy metals in wastewater and surface waters, which is a global environmental problem, has increased with the expansion of various industrial activities. Heavy metals cause serious health problems due to their accumulation in human and animal tissues. Thorium, is a radioactive element with an atomic number of 90 that is widely used in the optics, aerospace, metallurgy and chemical industries, in the manufacture of high-strength alloys, in UV photocells, and especially in the nuclear industry. The primary sources of radioactive wastewater include nuclear power plants, nuclear energy industry research centers, medical institutions, industrial production, universities,... 

As nuclear energy continues to be used as a useful energy resource, waste management, especially management of high-level nuclear waste (HLW), will always be a major concern, as the future generations should not be deprived of the valuable benefits of this energy. Vitrification of liquid high-level radioactive waste (HLW) has received greater attention, worldwide, than any other high-level waste solidification process. The high solubility of HLW in borosilicate glass, the controllable temperature of this type of glass and its low leaching rate in repository environment, have introduced borosilicate glass as a suitable host for HLW immobilization. In this project, the immobilization of the... 

According to Iran’s energy policies, the natural gas transmission pipeline has expanded significantly over the last decade. Moreover, improving energy efficiency is known as a key strategy in energy policies and programs. Therefore, the need for expansion and development of the rational use of energy has received more and more attention. The use of technologies aimed at energy recovery will be an effective step in this regard. Pressure regulators are most commonly used to reduce this pressure in Iran as one of the significant sources of exergy destruction in Iranian gas transmission system. The turbo-expander system is a kind of technology applied in gas pressure reduction stations to... 

Heating demand required for greenhouses is mainly met by fossil fuels. On the other hand, anxieties over usage of fossil fuels have led the societies to move toward renewable energies. With this in mind, the purpose of this research is to analyze using both solar energy for satisfying the heating demand of greenhouses and heat storage for compensating the intermittence of renewable energy.Considering the mentioned points, in the current research, a linear optimization framework has been developed for design and operation of energy systems including long-term heat storage to meet heating demand of greenhouses. The objective of this framework is to minimize annual cost. The developed method... 

The power generation system of this type of power plants operates on the air flowing through the power plant’s chimney and colliding with the turbine blades within the chimney. When the solar collector warms the nearby air and thus expands the air by absorbing the sunlight, a difference is created in the density. Then, this difference in the density creates the phenomenon of buoyancy, making the air pass to the top of the chimney through the collector.This study simulated and optimized a solar chimney power plant. The simulation and optimization were performed based on the information of Manzanares Solar Chimney Power Plant in Spain (located in 150 km from the south of Madrid). It was... 

Heat losses and pump electrical energy consumption are inevitable during the operation of a district heating(DH) network. Therefore, the appropriate design and operating strategy of a DH network is required in order to reduce the heat losses and pump energy consumption. This study is aimed at optimizing pipe diameters and mass flow rate in a DH network according to heat demand of the building in order to minimizing operating cost of the network.For this purpose first drawings of the building is modeled in Auto Cad software. Then according to the position of building to the sun, the building is modeled in Desighn Builder software. In this software the buildings charactersitics like materials... 

Natural Boron consists of two stable isotopes, 10B (19.3%) and 11B (80.7%). 10B isotope has a large thermal neutron absorption and therefore, use widely in such aspects as modern industry, atomic energy industry (as control rods, chemical shim and etc.), Medical science and applications in disclosing neutrons to measure neutron reactors fluxes. Boron trifluoride is most importantly used as a reagent in organic synthesis, typically as a Lewis acid. In this study, we designed and built the related setup for preparation of high purity BF3 gas. And then we tried to optimize the efficiency with process design tools such as response surface methodology (RSM). At the end of this study, we were able... 

In the past due to the lack of mechanical systems for air conditioning in the interior spaces, the buildings were designed to be able to maximize the use of natural forces such as solar and wind power. Natural ventilation is an old method of using natural forces. For example, wind tower is one of the traditional elements for using natural ventilation in the warm seasons for benefiting from wind and sun energy. In our country, Iran, in cities like Yazd, which are located in a warm and dry climate, the use of wind towers is very common and our predecessors were pioneer in this field. With the passage of time and the development of mechanical air conditioning systems, the use of natural... 

In line with the energy policies of the country, which is based on the development of the natural gas system, the natural gas transmission sector has also had a significant expansion during this period, especially in recent years. On the other hand, the promotion of energy efficiency has been a major issue in energy policies and programs. Therefore, the necessity of expanding and developing the rational use of energy has been considered more than ever. The use of energy recovery technologies will be an effective step in this regard. Owing to the wide expansion of gas pressure regulating stations in Iran and the high potential losses in pressure relief valves, substituting an expansion... 

In this project, a comprehensive methodology is developed to present the lifetime management and optimization framework for hybrid renewable energy systems. The main purpose of this work is to minimize the lifetime cost and improve the system reliability based on the interaction between different optimization levels related to different steps in the system lifetime. The proposed methodology is generally presented by providing a connection between the three specified optimization levels: 1) Planning: including design and long-term optimization models which is performed before system operation, 2) Real-time operation: By employing the receding horizon optimization which is applied from the... 

In this thesis a computational method for the design of optimum nozzle contour with consideration for chemical reactions has been presented. This method combines the method of characteristics, CFD and an optimization algorithm to develop a nozzle suitable for a specific operational condition. First using the method of characteristics an isentropic nozzle contour is achieved. then using the FLUENT solver, this initial contour is solved for flow containing finite-rate reactions and boundary layer effects and by iterating this process combined with an optimization algorithm, an optimum nozzle is found. Properties took into consideration in this method, in addition to chemical reaction between... 

PET systems are a kind of functional nuclear medicine instruments. In this systems a radionuclide is injected to body and output gamma rays is detected. PET can recognise cancer 10 times earlier than other imaging systems such as CT scan also the treatment plan can followed by PET. In the last two decades, the use of small-animal models in the field of biomedical research for studying disease have accelerated and dedicated small animal PET systems have started playing their role as strong imaging modalities in investigating cellular and molecular processes in live animals. Animal and human PETs have similar technology just human PET is bigger, so at this project, animal PET is designed for... 

Due to the growth of energy consumption the use of new technologies and efficient energy conversion is necessary. An example of efficient energy conversion technology is CCHP (Combined Cooling, Heating and Power). The aim of the present research work is to develop a model that could be applied for optimal design of a hybrid CCHP system which would be Solar Combined Cooling, Heating and Power (SCCHP). In order to do so,microturbine power system, cooling and heating equipment’s such as absorption system and heat exchanger and also solar collector have been considered as an integral part of the system. The objective of the application of the model has been to identify proper sizing of all... 

Hydro power is a clean energy resource which has numerous advantages over other renewable energy systems including competitiveness with fossil fuel systems, high reliability, considerable potential, and availability of technology. These advantages have drawn attention to hydropower systems. Small Hydro Power (SHP) systems can be used for supplying the demand of rural and remote areas where electricity network rarely exists. SHP may also provide an investment opportunity. Comprehensive analysis of design features and operation of SHP and management of risks involved requires development and application of reliable analytical tools. The present research aims at developing a model for optimal...