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Application of endurance time method in performance-based design of steel moment frames
, Article Scientia Iranica ; Volume 17, Issue 6 A , 2010 , Pages 482-492 ; 10263098 (ISSN) ; Estekanchi, H. E ; Vafai, A ; Sharif University of Technology
2010
Abstract
In this paper, application of the Endurance Time (ET) method in the performance-based design of steel moment frames is explained from a conceptual viewpoint. ET is a new dynamic pushover procedure that predicts the seismic performance of structures by subjecting them to a gradually intensifying dynamic action and monitoring their performance at various excitation levels. Structural responses at different excitation levels are obtained in a single time-history analysis, thus significantly reducing the computational demand. Results from three analyses are averaged to reduce the random scattering of the results at each time step. A target performance curve is presented based on the required...
A case study in vapor phase synthesis of Mg-Al alloy nanoparticles by plasma arc evaporation technique
, Article Chemical Engineering Journal ; Volume 259 , 2015 , Pages 918-926 ; 13858947 (ISSN) ; Derakhshan, R ; Mirzaee, O ; Sharif University of Technology
Elsevier
2015
Abstract
Alloy nanoparticles in the Mg-Al system were prepared by plasma arc discharge method from the Mgx to Al (45%
Simultaneous Analysis of Steam and Power Cogeneration in Tehran Refinery
, M.Sc. Thesis Sharif University of Technology ; Farhadi, Fatollah (Supervisor)
Abstract
Due to the increasing cost of energy, we want in this study to increase energy efficiency and reduce waste of system energy. Oil, gas and petrochemical sector is a widespeard part in Iran, so the study of energy systems in the industry have a paramount importance. The study focused on the Tehran refinery steam and power systems, seeking the most economical system of power and steam for the Tehran refinery. To achieve this goal, with the help of simulation of power and steam system for Tehran refinery with Aspen Utility software, a superstructure obtained. Then, using a sensitivity analysis, we were able to achieve economic arrangment of utility system. In this study by increasing the...
Exact simulating of human arteries using lumped model and probing constriction in femoral and carotid arteries
, Article American Journal of Applied Sciences ; Volume 6, Issue 5 , 2009 , Pages 834-842 ; 15469239 (ISSN) ; Ghasemalizadeh, O ; Firoozabadi, B ; Sharif University of Technology
2009
Abstract
Problem statement: Modeling Human cardiovascular system was always an important issue from long past because by doing such modeling, investigation in cardiovascular system and its abnormities would be simpler. One of the most effective ways to do such modeling is using lumped method (Electrical analogy). Approach: Lumped method was used for simulating a complete model in this approach. A 36-vessel model was chosen to make equivalent circuit of lumped method from it. This complicated circuit includes equivalent segment for arteries, pulmonary, atrium, left and right ventricles. Furthermore, in this complex circuit some additional points were considered to improve this method. Some of the most...
Modeling Gaseous Air Pollutants Concentration in Tehran Using Artificial Neural Network and Land Use Regression
, M.Sc. Thesis Sharif University of Technology ; Mohammad Arhami (Supervisor) ; Amini, Zahra (Co-Supervisor)
Abstract
In this thesis the hourly concentration of different gaseous air pollutants in Tehran is modeled using Land Use Regression (LUR) and Artificial Neural Network, separately. Both models are provided with the same set of input data; the first step is to find these data. Since traffic affects air pollution, information about traffic conditions is one of the main inputs in air pollution modeling. Therefore, to obtain traffic information, in this thesis, first a novel method is developed to extract and analyze Google Maps traffic data. In this method, image processing is used along with the Geographic Information System (GIS) to count the number of pixels of different traffic colors for each road...
A dual-frame hybrid vector control of vector-modulated VIENNA I rectifier for unity power factor operation under unbalanced mains condition
, Article 2008 23rd Annual IEEE Applied Power Electronics Conference and Exposition, APEC, Austin, TX, 24 February 2008 through 28 February 2008 ; 24-28 Feb , 2008 , Pages 1402-1408 ; 10482334 (ISSN) ; 9781424418749 (ISBN) ; Moallem, A ; Zolghadri, M. R ; Ferdowsi, M ; Sharif University of Technology
2008
Abstract
In this paper, a dual-frame hybrid vector control (DFHVC) of vector-modulated VIENNA I rectifier is proposed. The purpose of this novel vector control system is not only to reduce second-order harmonic pulsation on the dc-side and consequently, to reduce odd-order harmonics on the ac side of VIENNA I rectifier under unbalanced mains, but also to ensure a near unity power factor operation of the rectifier under such circumstances. To serve this purpose, at first, a mathematical model of the VIENNA I rectifier under unbalanced condition is derived. In this model, besides demonstrating the nonlinear nature of the DC-link voltage dynamic, a new set of equations for current reference generation...
Effect of the pyrrolic nitrogen functional group in the selective adsorption of CO2: GCMC, MD, and DFT studies
, Article Energy and Fuels ; Volume 35, Issue 19 , 2021 , Pages 15918-15934 ; 08870624 (ISSN) ; Mirzaee Valadi, F.M ; Latifi Pour, M ; Rashtchian, D ; Gholami, M. R ; Sharif University of Technology
American Chemical Society
2021
Abstract
In this paper, the pyrrolic nitrogen functional group's presence is investigated in the selective adsorption of CO2. The grand canonical Monte Carlo (GCMC), molecular dynamics (MD), and density functional theory (DFT) were used for this study's goal. GCMC was used to calculate adsorption isotherms, selectivity, and isosteric heats. MD was used to calculate the radial distribution function (RDF) and diffusion. Reactivity parameters, electrostatic potential (ESP), reduced density gradient (RDG), and independent gradient model (IGM) were calculated using DFT. Adsorption isotherms, selectivity, and isosteric heats demonstrated that the NH group caused the selective adsorption of CO2 among CH4,...
Investigating the Logistic of Chabahar Free Zone by Data Analysis Tools
, M.Sc. Thesis Sharif University of Technology ; Mashayekhi, Ali Naghi (Supervisor) ; Aslani, Shirin (Supervisor)
Abstract
In recent years, the application of data analysis in the field of management has grown significantly. One of the most important of these areas is operations. One of the key tasks of operations management is logistics management. Logistics means managing the flow of goods, information or any other source; Like energy or humans,it is between the place of production or the place of inventory to the place of consumption. Logistics is the art and science of acquiring production, distributing materials and products in the right amount and place. Logistics includes information integration, transportation, inventory, warehousing, handling and packaging.If the flow of goods is done properly; We will...
Development of a Computer Code for Thermal Hydraulic Design of a High Temperature Gas Cooled Reactor Core
, M.Sc. Thesis Sharif University of Technology ; Ghofrani, Mohammad Bagher (Supervisor) ; Jafari, Jalil (Supervisor)
Abstract
High temperature gas cooled reactors (HTGR) are one of the most promising reactors in the new generation of world commercial reactors. They are divided into two main categories: Prismatic gas cooled reactors and pebble bed gas cooled reactors. These reactors have many advantages, such as inherent safety, high thermodynamic efficiency and the possibility of producing hydrogen. One of the most important challenges in developing these reactors is providing appropriate codes in design and simulating their performance. Two codes have been developed in this thesis. The first, THFAM, is a steady state thermal hydraulic code which helps in analyzing a fuel assembly. The second, named THCM is...
Separaition of Cu 2+ Ions from Aques Medium Using Silica Nano Pore Functionalized Amine Groups Confiend with Ionic Liquid
, M.Sc. Thesis Sharif University of Technology ; Mohammad , Mahmoudi Hashemi (Supervisor) ; Mirzaee, Mohammad (Supervisor)
Abstract
Purification of waste water containing metal ions, is one of major environmental problems which have threaten human’s life, other creatures and even agricultural products by means of polluting suberranean water. Copper ion is one of dangerous heavy metals that exists in potable water and agricultural uses, due to serious problems in health of humans and aquatic. In recent years, different methods for purification of waste water containing heavy metal ions have been published. Right now, thorough these methods such as: filtration, coagulation, precipitation and adsorption are being used, which have their own advantages and disadvantages.In this research, new method for purification of waste...
Effect of heating profile on desorption curve in temperature programmed desorption analysis: Case study of acid sites distribution of SAPO-34
, Article Journal of Porous Materials ; Volume 16, Issue 5 , 2009 , Pages 599-603 ; 13802224 (ISSN) ; Farhadi, F ; Khorasheh, F ; Yan, Z. F ; Sharif University of Technology
2009
Abstract
Comparison of the traditional linear heating method of TPD with an original stepwise heating scheme was reported for the first time. Stepwise heating TPD was carried out by keeping the temperature constant as soon as ammonia desorption signal rises until the signal returns to the baseline. More ammonia desorption peaks on a SAPO-34 catalyst were identified using TPD with stepwise heating. The effect of temperature ramp on desorption peak broadening in TPD curve was also addressed. The more distinct ammonia desorption peaks in stepwise TPD indicates that ammonia adsorbs in about five or six different ways on SAPO-34, and attribution of different adsorptions may be explained considering some...
Theoretical and experimental study of cascade solar stills
, Article Solar Energy ; Volume 90 , April , 2013 , Pages 205-211 ; 0038092X (ISSN) ; Sharak, A. Z ; Moghadam, H ; Tabrizi, F. F ; Sharif University of Technology
2013
Abstract
Most part of Iran is dominated by arid and semi-arid areas due to low annual rainfall. The need for production of fresh water from brackish water is considerably high, especially in dry regions. In this study 1 month daily-based experimental data from a solar still site has been reported. The technical and operational problems of this site which finally contributed to the total cease of the site are described. Then a detailed analysis is investigated on progress of a prototype which constructed in order to solve the site's problems. The results of 1 month of experimental data of the final design showed that the last prototype could be used to solve the current problems of the site. The...
Application of a continuous kinetic model for the hydrocracking of vacuum gas oil
, Article Petroleum Science and Technology ; Vol. 32, Issue. 18 , 2014 , Pages 2245-2252 ; ISSN: 10916466 ; Khorasheh, F ; Farhadi, F ; Sharif University of Technology
2014
Abstract
Hydrocracking is one of the most versatile petroleum refining processes for production of valuable products including gasoline, gas oil, and jet fuel. In this paper, a five-parameter continuous lumping model was used for kinetic modeling of hydrocracking of vacuum gas oil (VGO). The model parameters were estimated from industrial data obtained from a fixed bed reactor operating at an average temperature of 400°C and residence time of 0.3 h. Product distributions were obtained in terms of the weight fraction of various boiling point cuts. The model parameters were estimated using the Nelder-Mead optimization procedure and were correlated with temperature. Comparison of experimental and...
An improved methodology for design of custom-made hip prostheses to be fabricated using additive manufacturing technologies
, Article Rapid Prototyping Journal ; Volume 18, Issue 5 , 2012 , Pages 389-400 ; 13552546 (ISSN) ; Abbaszadeh, F ; Farahmand, F ; Sharif University of Technology
Emerald
2012
Abstract
Purpose - The purpose of this paper is to present an improved methodology for design of custom-made hip prostheses, through integration of advanced image processing, computer aided design (CAD) and additive manufacturing (AM) technologies. Design/methodology/approach - The proposed methodology for design of custom-made hip prostheses is based on an independent design criterion for each of the intra-medullary and extra-medullary portions of the prosthesis. The intra-medullar part of the prosthesis is designed using a more accurate and detailed description of the 3D geometry of the femoral intra-medullary cavity, including the septum calcar ridge, so that an improved fill and fit performance...
Evaluation and enhancing of operational performance and training objective in accordance with Line Operations Safety Audit (LOSA)
, Article International Air Safety Seminar Proceedings, 1 November 2011 through 3 November 2011 ; November , 2011 , Pages 78-99 ; 02705176 (ISSN) ; 9781618393975 (ISBN) ; Goodarzi, F ; Sharafbafi, F ; Sharif University of Technology
2011
Real-time impulse noise suppression from images using an efficient weighted-average filtering
, Article IEEE Signal Processing Letters ; Volume 22, Issue 8 , 2015 , Pages 1050-1054 ; 10709908 (ISSN) ; Hessar, F ; Marvasti, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
In this letter, we propose a method for real-time high density impulse noise suppression from images. In our method, we first apply an impulse detector to identify the corrupted pixels and then employ an innovative weighted-average filter to restore them. The filter takes the nearest neighboring interpolated image as the initial image and computes the weights according to the relative positions of the corrupted and uncorrupted pixels. Experimental results show that the proposed method outperforms the best existing methods in both PSNR measure and visual quality and is quite suitable for real-time applications
Kinetic modeling of pyrolysis of scrap tires
, Article Journal of Analytical and Applied Pyrolysis ; Volume 84, Issue 2 , 2009 , Pages 157-164 ; 01652370 (ISSN) ; Farhadi, F ; Khorasheh, F ; Sharif University of Technology
2009
Abstract
The disposal of used tires is a major environmental problem. With increasing interest on recovery of wastes, pyrolysis is considered as an alternative process for recovering some of the value in scrap tires. An accurate kinetic model is required to predict product yields during thermal or catalytic pyrolysis of scrap tires. Pyrolysis products contain a variety of hydrocarbons over a wide boiling range. A common approach for kinetic modeling of such complex systems is lumping where each lump is defined by a boiling point range. Available experimental data for thermal and catalytic pyrolysis of scrap tires from the literature were used to evaluate two types of lumping models; discrete and...
Determine oil content in petroleum waxes
, Article Hydrocarbon Processing ; Volume 85, Issue 6 , 2006 , Pages 95-97 ; 00188190 (ISSN) ; Yazdani, F ; Farhadi, F ; Sharif University of Technology
2006
Analytical modeling of variable-reluctance tubular resolver based on magnetic equivalent circuit and conformal mapping
, Article IEEE Transactions on Instrumentation and Measurement ; Volume 70 , 2021 ; 00189456 (ISSN) ; Zare, F ; Tootoonchian, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
Compared with flat linear structures, tubular linear machines do not face edge effects, making their performance better than their flat counterparts. In this article, a novel linear variable-reluctance resolver with tubular configuration is proposed. To optimize the design of an electromagnetic structure, modeling methods are used. Thus, in this article, an analytical model for the proposed resolver is presented. This model is based on the magnetic equivalent circuit (MEC) method and is considerably less time-consuming than finite element analysis (FEA), yet provides accurate results. A conformal mapping is employed to compute the permeance of the air-gap. The proposed model is then utilized...
Information and the Brukner-Zeilinger interpretation of quantum mechanics: A critical investigation
, Article Foundations of Physics Letters ; Volume 19, Issue 1 , 2006 , Pages 1-20 ; 08949875 (ISSN) ; Safinejad, F ; Naqsh, F ; Sharif University of Technology
2006
Abstract
In Brukner and Zeilinger's interpretation of quantum mechanics, information is introduced as the most fundamental notion and the finiteness of information is considered as an essential feature of quantum systems. They also define a new measure of information which is inherently different from the Shannon information and try to show that the latter is not useful in defining the information content in a quantum object. Here, we show that there are serious problems in their approach which make their efforts unsatisfactory. The finiteness of information does not explain how objective results appear in experiments and what an instantaneous change in the so-called information vector (or catalog of...