Loading...
Search for:
rahemi--bijan
0.118 seconds
Total 215 records
Providing Methods for Reducing and Estimating the Power Consumption of Wireless Networks on Chip
, M.Sc. Thesis Sharif University of Technology ; Tabandeh, Mahmoud (Supervisor) ; Rahemi, Bijan (Supervisor)
Abstract
In recent years, the possibility of building large systems on chip, called SoC is provided. By scaling the technology, designing Socs will face numerous challenges. The Noc paradigm, has resolved many of the SoC’s problems, by deploying network properties in the structures of on chip interconnections. Today, with advances in the semiconductor industry, we can implement broadband wireless antennas, which are integrated on chip. Such NoCs are called WNoC. Due to immaturity of WNoCs, there still exist big challenges, providing routing algorithm and controlling shared medium via MAV layers, for them. In this project, we will provide a routing algorithm based on tag switching, and then, after...
Effect of water-cement ratio on abrasive strength, porosity and permeability of nano-silica concrete
, Article World Applied Sciences Journal ; Volume 17, Issue 8 , 2012 , Pages 929-933 ; 18184952 (ISSN) ; Peroti, S ; Rahmani, K ; Rahemi, L ; Sharif University of Technology
2012
Abstract
Today, due to rapid development of construction of hydraulic structures like dams, the constituent material used in concrete and its durability in these kinds of structures has gained dominant interests and importance. One of the important factors of concrete durability in these structures is its resistance against abrasion due to crash of particles carried out as hydrated crystalline particulate matter. To enhance the abrasion resistance of concrete, different methods have been offered and investigated by many research3ers/ The aim of present article is to investigate the important parameter i.e. water-cement ratio on abrasive strength, porosity and the coefficient of hydraulic conductivity...
The effect of water-cement ratio in compressive and abrasion strength of the nano silica concretes
, Article World Applied Sciences Journal ; Volume 17, Issue 4 , 2012 , Pages 540-545 ; 18184952 (ISSN) ; Rahmani, K ; Peroti, S ; Rahemi, L ; Sharif University of Technology
2012
Abstract
Development and construction of hydraulic structures like dams, the concrete durability in these kinds of structures has gained special attention. One of the crucial factor in concrete technology is it durability in hydraulic structures. Concrete has to resist against abrasion due to the crash of particles carried by water. To enhance the abrasion resistance of concrete different methods have been offered. In the present stud, the role of water-cement ratio in compressive and abrasion strength of nano silica concrete was investigated. The constructed concrete samples with 3% nano silica and water-cement ratios of 0.33, 0.36, 0.40, 0.44 and 0.50 were experimented. Other design features...
N-doped ZnO-CuO nanocomposite prepared by one-step ultrasonic spray pyrolysis and its photocatalytic activity
, Article Chemical Physics Letters ; Volume 705 , 2018 , Pages 19-22 ; 00092614 (ISSN) ; Sabour Rouhaghdam, A ; Nazari, M ; Sharif University of Technology
Elsevier B.V
2018
Abstract
Nanocomposite thin film of N-doped ZnO-CuO was deposited on glass substrate using ultrasonic spray pyrolysis method. Zinc acetate, copper acetate and ammonium acetate with different molar ratios were dissolved in water and used as precursors. A crumpled-shape morphology consisting of nanometer-sized particles was observed with FESEM. The elemental composition was evaluated with EDX analysis and the presence of nitrogen, oxygen, copper and zinc was confirmed. XRD analysis revealed the presence of ZnO and CuO crystalline phases with crystallite size of about 18 nm. The prepared nanocomposites exhibited high photocatalytic activity in degradation of methyl orange under UV light irradiation. ©...
Computer simulation of knee arthrometry to study the effects of partial ACL injury and tibiofemoral contact
, Article 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS'08, Vancouver, BC, 20 August 2008 through 25 August 2008 ; 2008 , Pages 895-898 ; 9781424418152 (ISBN) ; Farahmand, F ; Rezaeian, T ; Parnianpour, M ; Sharif University of Technology
IEEE Computer Society
2008
Abstract
We simulated the knee arthrometry test to obtain a deeper understanding of the joint's stability behavior and interpret the arthrometric results more effectively. A 2D sagittal plane finite element model of the lower limb in the standard configuration of knee arthrometry was developed using ANSYS APDL. A detailed model of the knee joint was considered including the femoral articulating contour represented by an ellipse, the tibial plateau represented by a circular arc, and four major knee ligaments and their individual bundles represented by linear and nonlinear tensile springs. A deformable layer of articular cartilage was also considered over the tibial plateau to simulate the bones...
Computer Simulation of Arthrometric Diagnosis of Partial ACL-Injured Knee
, M.Sc. Thesis Sharif University of Technology ; Farahmand, Farzam (Supervisor) ; Parnianpour, Mohammad (Supervisor)
Abstract
Knee pain and injuries are very common in athletes. Anterior cruciate ligament (ACL) injury is one of the most important reason of knee acute and chronic pains. As ACL plays a significant role in knee stability and due to amount of reported ACL related injuries, much effort has been placed on finding proper and on time diagnosis and treatment of these injuries. Arthrometric methods are the most non-invasive reliable diagnosis option; however they are not fully capable of separating partial injuries from intact joint. This weakness can be investigated by quantifying the tests using computer simulations; so far few studies have been conducted toward this goal. In this study a two dimensional...
Bioethanol supply chain network design considering land characteristics
, Article Renewable and Sustainable Energy Reviews ; Volume 119 , 2020 ; Torabi, S. A ; Avami, A ; Jolai, F ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Biomass is becoming an increasingly widespread source of energy. Yet land, as one of the most important resources in biomass production, is surprisingly understudied in the literature of biomass supply chain planning. This study proposes a novel framework that combines the literature of bioethanol supply chain design with agricultural land planning to simultaneously address optimal supply chain planning and sustainable land use in a bioethanol supply chain. A bi-objective mixed-integer linear programming (MILP) model is proposed to formulate the optimal design and planning of a bioethanol supply chain network considering competition of food and biomass feedstock over the available croplands....
Design of a Fault Tolerant SPARC Based Micro Processor On FPGA
, M.Sc. Thesis Sharif University of Technology ; Rashidian, Bijan (Supervisor) ; Vosoughi Vahdat, Bijan (Supervisor)
Abstract
In this thesis, LEON Processor was chosen for its compatible architecture that can be implemented on a wide range of FPGAs. The final designed processor is aimed to conquer soft and hard errors that occur due to cosmic radiations in SRAM cells of an FPGA. The system can finally resist all single SEUs that happen in flip flops and all 4 random errors that take place in each register of the register file. All the flip flops and latches are protected using a TMR scheme. The information redundancy in the regiester file to overcome all 4 random errors is 168% and the errors are corrected by means of a mechanesim that is masked from the processor core. In cache memory, each 32 bit data is...
Design of a Fault Tolerant ARM-Based Processor on FPGA
, M.Sc. Thesis Sharif University of Technology ; Rashidian, Bijan (Supervisor) ; Vosughi Vahdat, Bijan (Supervisor)
Abstract
The charged particles in space strike the silicon surface of an embedded system in a satellite and cause fault occurrence in its operation. So some methods should be employed to reduce the effects of the faults. The methods that are implemented in system level are widely used because of their low cost and high reliability. The processors are responsible for performing main processes in embedded systems. On the other hand, the ARM processors are good choices for utilizing in satellites because of their low size, low power consumption and high performance. Also, FPGAs have made a major improvement in embedded system design. So with implementing ...
Methodology of Religious ScienceWith Respect to Dr.Golshani’s Theory of Religious Scienceand Dr.Khosropanah’s Hikmai-Ejtihadi’s Pattern on Humanities
, M.Sc. Thesis Sharif University of Technology ; Golshani, Mehdi (Supervisor) ; Khosropanah, Abdolhossien (Co-Advisor)
Abstract
If we accept that there is a thing called “religious Science”, then we should accept that, all of its scientific elements should be based on, or be compatible with religion (in its general meaning). So, here is the question: Is there a particular “religious methodology” required for the “religious science”? Does “religious”, as an adjective also applies to methodology of science? Anyway, if we want to generate “religious science” based on religious foundations, we should characterize our position about “methodology of religious science”. Negligence of this important subject would cause a theoretical vacuum in discussions about religious science. In this thesis, after explaining some general...
Characterization of Elecroless Ni-P-Al2O3-SiO2 Nano-composite Coating on Aluminium
, M.Sc. Thesis Sharif University of Technology ; Afshar, Abdollah (Supervisor) ; Dolati, Abolghasem (Supervisor)
Abstract
In this study Ni-P-Al2O3-SiO2 nano composite coating developed on aluminium alloy 6061 using electroless method. Due to oxidation of aluminium, a double zincate pretreatment performed to obtain proper adhesion of coating on substrate. Effect of solution temperature and heat treatment on thickness and property of nano composite coating was studied. Furthermore, effect of concentration of nano particles in electroless solution on thickness, morphology, micro hardness, wear behavior, corrosion resistance and particle content in coating were investigated. Field emission scanning electron microscopy (FESEM, Hitachi S-4160) with energy dispersive spectroscopy (EDS) was used to evaluate morphology...
Characterization of Ni-P-SiO2-Al2O3 nano-composite coatings on aluminum substrate
, Article Materials Chemistry and Physics ; Volume 189 , 2017 , Pages 207-214 ; 02540584 (ISSN) ; Afshar, A ; Sadreddini, S ; Ghanbari, A. A ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
In the present work, nano-composites of Ni-P-SiO2-Al2O3 were coated on a 6061 aluminum substrate. The surface morphology of the nano-composite coating was studied by field emission scanning electron microscopy (FESEM). The amount of SiO2 in the coating was determined by Energy Dispersive Analysis of X-Ray (EDX) and the crystalline structure of the coating was examined by X-ray diffractometer (XRD). All the experiments concerning the corrosion behavior of the coating carried out in 3.5%wt NaCl solution and evaluated by electrochemical impedance spectroscopy (EIS) and polarization technique. The results showed that an incorporation of SiO2 and Al2O3 in Ni-P coating at the SiO2 concentration of...
Low Grade Heat Driven Multi-Effect Distillation and Desalination
, Book ; Chua, Hui Tong
Elsevier
2017
Abstract
Low Grade Heat Driven Multi-effect Distillation and Desalination describes the development of advanced multi-effect evaporation technologies that are driven by low grade sensible heat, including process waste heat in refineries, heat rejection from diesel generators or microturbines, and solar and geothermal energy. The technologies discussed can be applied to desalination in remote areas, purifying produced water in oil-and-gas industries, and to re-concentrate process liquor in refineries.
This book is ideal for researchers, engineering scientists, graduate students, and industrial practitioners working in the desalination, petrochemical, and mineral refining sectors, helping them...
This book is ideal for researchers, engineering scientists, graduate students, and industrial practitioners working in the desalination, petrochemical, and mineral refining sectors, helping them...
Numerical Investigation of Two-Phase Flow Contains Water and Oil in Hydrocyclones
, M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan (Supervisor)
Abstract
Having an efficient and reliable system for oil-water separation is of crucial importance in oil and gas industry. Hydrocyclones have been used for more than a century to separate oil from water as well as sand from liquid or gas. The main objectives of this research are as follows: Determination the hydrocyclone principle of operation, based on computational fluid dynamic simulations. Hydrocyclones, in a spite of simple structure, are widely used in industry such as Petrochemical, Mining, Chemical Industries, Pharmacy, Food and Pulp Industries. The CALC BFC is one phase flow numerical code based on finite volume method and SIMPLEC algorithm. It was extended for simulating the two phase flow...
Deposition and Analysis of Indium-Tin-Oxide NanoStructures Using Sputtering
, M.Sc. Thesis Sharif University of Technology ; Rashidian, Bijan (Supervisor)
Abstract
Transparent conductive materials have been widely used in semiconductor technology. Among them all, Indium tin oxide (ITO) has been utilized as electrodes in liquid crystal displays, solar cells, heat reflecting films and gas sensors.In general, the desired properties of transparent conductive oxides are high conductance and transmission. However, due to the complexity of ITO molecular structure, the film properties strongly depend on the depositon parameters.In first part of this thesis, physical properties and electrical characteristic of ITO films, different deposition techniques, and effects of deposition parameters (substrate temperature, pressure, power, etc. ) on film properties are...
Fabrication of Metallic Nano-Tip Field Emitters and Measurement
, M.Sc. Thesis Sharif University of Technology ; Rashidian, Bijan (Supervisor)
Abstract
The need for integration of electron guns together with thermal considerations of thermionic cathodes has led to design new cold cathode guns based on field emission phenomenon. In first part of this thesis, basic field emission theories, fabrication methods of field emitter arrays, effect of different parameters on the field emission properties of field emitter arrays and applications of these arrays are investigated. After setting up fabrication methods of nano-tip field emitters, in the second part of thesis, Si nano-tips and Si field emitter arrays are fabricated using of thermal oxidation of silicon substrate, lithography, and chemical etching of silicon oxide and silicon substrate. Si...
, M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan (Supervisor)
Abstract
Centrifugal Fans are widely used in industrial and commercial applications, from shop ventilation to material handling to boiler applications. They consume extremely high amount of energy each year. Because of this high consumption, even a small efficiency improvement could led to high amount of energy saving. Many projects have been done with this goal up to now, and present work is one of them, with aim to optimize a industrial centrifugal BI fan performance, with wheel diameter about 400 mm. The research has been done based on 3D numerical methods, done by commercial code Fluent 6.3, in steady state. MRF and k-E models have been used to simulate flow around blades, and turbulence...
, M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan (Supervisor)
Abstract
Development of cities as well as population growth causes to development of public transportation especially subway lines. Fire is the one of the most important issues that may occur in subways. The difference in flame size, emission heat, smoke and pollutants generation of subway fires attracts an especial attention of fire investigators. The emergency ventilation of subways in the case of fire should have the ability of discharging heat, smoke and pollutants from passenger escape route and preparing a safe place for a specific duration. The aim of this research is simulating fire in subway stations and defining proper regional fire scenarios to prepare a safe route for passengers escape....
Numerical Investigation of Turbulent Flow Inside De-Oiling Hydrocyclones Using Large Eddy Simulation Approach
, M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan (Supervisor)
Abstract
Hydrocyclones are used for separating different materials from liquids in a variety of applications. Compactness, efficiency, reliability and low maintenance costs are their noteworthy characteristics. Dewatering and deoiling hydrocyclones used for refining crude oil or oily waste water in offshore platforms are examples of liquid-liquid hydrocyclones. Separation process in hydrocyclones is based on the fact that swirl flow induces a centrifugal force and leads to separation due to density difference. The density difference in liquid-liquid mixtures is smaller than solid-liquid types and trying to separate one liquid from another takes much more effort than the other type. Increase of...
Numerical Simulating of a Railcar fire in Tunnel
, M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan (Supervisor)
Abstract
Fire phenomenon and its hazards through urbun transportation systems like subway is a major debate in management of these territories. Recently, varios factors, such as great deal of passengers whom travel by these systems, financial damages and psychological disorders due to fire accidents resulte in noticeable investigation to prevent and reduce these subjects. In this research, simulating of railcar fire has been conducted to estimate the amount of heat release rate (HRR) and parameters which affect on it by modelling behavior of combustible materials inside railcar. As regards to materials which are available inside railcar that participate in fire, their behavior face to heat flux has...