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najafizadeh--mobarakeh
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A study of the reliability of various types of the electric vehicles
, Article 2012 IEEE International Electric Vehicle Conference, IEVC 2012 ; 2012 ; 9781467315623 (ISBN) ; Ghahnavieh, A. R ; Mobarakeh, A. S
2012
Abstract
The reliability Studies are done in order to determine the probability of functioning or availability of different engineering systems. These studies can also provide a basis for comparing different structures of a system and can be used as a tool to improve the system design. Also, reliability is an important consideration in the planning, design and operation of transit system. Since the issue of the reliability of electric vehicles has not been sufficiently and seriously evaluated yet, so in this paper, the reliability of the various types of these kinds of vehicles will be discussed and then the reliability indices of them will be compared with each other and with the conventional cars
Determination of Micro Encapsulation of Probiotic
, M.Sc. Thesis Sharif University of Technology ; Alemzadeh, Iran (Supervisor)
Abstract
Probiotics are defined as essential live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. In order to provide health benefits for probiotic bacteria it has been recommended that they must be present at a minimum level of 106 CFU/g of food product or 107 CFU/g at point of delivery or be eaten in sufficient amounts to yield a daily intake of 108 CFU. Several studies have shown that certain strain of lactic acid bacteria, such as Bifidobacterium bifidum and Lactobacillus acidophilus prevent some diseases linked to the gastro-intestinal tract. however, many reports have demonstrated their poor survival and stability. Their survival in the...
Vibration analysis of spinning cylindrical shell made of functionally graded material using higher order shear deformation theory
, Article 7th European Conference on Structural Dynamics, EURODYN 2008, 7 July 2008 through 9 July 2008 ; 2008 ; 9780854328826 (ISBN) ; Mehrparvar, M ; Najafizadeh, A ; Sharif University of Technology
University of Southampton, Institute of Sound Vibration and Research
2008
Abstract
In this paper the vibration of a spinning cylindrical shell made of functional graded material (FGM) made is investigated. After a brief introduction of FG materials, by employing higher order theory for shell deformation, constitutive relationships are derived. In the next step by utilizing energy method and Hamilton's principle governing deferential equation of spinning cylindrical shell is obtained. By making use of the principle of minimum potential energy, the characteristic equation of natural frequencies is derived. After verification of the results, the effect of changing different parameters such as material grade, L/R, h/R, and spinning velocity on the natural frequency are...
Proof Search Analysis in Sequent Calculus for Intuitionistic Logic
, M.Sc. Thesis Sharif University of Technology ; Ardeshir, Mohammad (Supervisor)
Abstract
In this thesis the sequent calculi for intuitionistic logic have been studied and compared with these calculi in classical logic, moreover soundness and completeness theorems for these calculi have been proved. Also an algorithmic method is presented to construct the proof-search with this feature that proof-search terminates and the subformula property preserved. In particular the analysis and comparison of two calculi IG and SIC provided by Tassi and Corsi have been done. Finally, we consider the calculus SJC, stack-based Jankov calculus which is similar to SIC and describes proof-search procedure for weak excluded middle logic. If the proof-search is successful in each calculus SIC or...
Time Series Analysis Using Deep Neural Networks Based on DTW Kernels and its Application in Blood Pressure Estimation Using PPG Signals
, M.Sc. Thesis Sharif University of Technology ; Mohammadzadeh, Narjesolhoda (Supervisor)
Abstract
This work presents a modification of deep neural networks for time series analysis. We used kernel layer(s), as a novel approach, at the beginning of the common deep neural networks. These kernels learn based on dynamic time warping (DTW). In each kernel, DTW is calculated between the kernel value and a part of input time series or a part of last layer output (if the kernel is not in the first layer). DTW also gives an alignment path for the input series. This alignment path is used to defining a loss function with the goal of getting better alignment (lower DTW distance) between the kernel and the other input. Besides getting better accuracy on the examined datasets, the other achievement...
Actuator/sensor modeling for vibration of FGM solid circular plate using Reissner-Mindlin plate theory
, Article ZAMM Zeitschrift fur Angewandte Mathematik und Mechanik ; Volume 90, Issue 4 , 2010 , Pages 287-308 ; 00442267 (ISSN) ; Kargarnovin, M. H ; Najafizadeh, M. M ; Sharif University of Technology
2010
Abstract
In this paper, the vibration of a constant thickness circular plate made of functionally graded material (FGM) is controlled by implementing two piezoelectric layers as a sensor and an actuator. Assuming that the material properties of FGM plate vary only in the thickness direction according to the power law manner, the governing differential equations are derived based on the Reissner-Mindlin plate theory (RMPT). Moreover, in a parallel work another set of differential equations are also derived using classical plate theory (CPT). Then for two different kinds of plate boundary conditions these coupled differential equations are solved using separation of variable technique and obtained...
Free vibration analysis of functionally graded coupled circular plate with piezoelectric layers
, Article Journal of Mechanical Science and Technology ; Volume 23, Issue 8 , 2009 , Pages 2008-2021 ; 1738494X (ISSN) ; Kargarnovin, M. H ; Najafizadeh, M. M ; Sharif University of Technology
2009
Abstract
Based on classical plate theory (CLPT), free vibration analysis of a circular plate composed of functionally graded material (FGM) with its upper and lower surfaces bounded by two piezoelectric layers was performed. Assuming that the material properties vary in a power law manner within the thickness of the plate the governing differential equations are derived. The distribution of electric potential along the thickness direction in piezoelectric layers is considered to vary quadratically such that the Maxwell static electricity equation is satisfied. Then these equations are solved analytically for two different boundary conditions, namely clamped and simply supported edges. The validity of...
Optimal Contract Pricing of Distributed Generation in Iran
, M.Sc. Thesis Sharif University of Technology ; Rajabi-Ghahnavieh, Abbas (Supervisor)
Abstract
Increase in electricity demands and expansion cost of the power system as well as raising more concerns on environmental issues have led to increasing attraction towards Distributed Generation (DG) application in power systems. DG is generally defined as small generation units, ranging from several KW to several MW, that are installed on the distribution network. In Iran, the energy generated by DG units is purchased by Tavanir or distribution companies through guaranteed fixed-price purchase contract. The contract price imposes substantial effects on the cost and benefit of DG owners as well as those of the distribution company (DisCo). A logical and fair pricing model can provide more...
A game theoretic framework for DG optimal contract pricing
, Article 2013 4th IEEE/PES Innovative Smart Grid Technologies Europe, ISGT Europe 2013 ; 2013 ; 9781479929849 (ISBN) ; Rajabi-Ghahnavieh, A ; Zahedian, A ; Sharif University of Technology
2013
Abstract
This paper presents a new approach based on multi leader follower game in order to find the optimal contract price of distributed generation in distribution network considering competition among them. The leader problems correspond to the independent DG units who decide to maximize the individual profits, while the follower problem refers to the distribution company (DisCo) which seeks the minimization of the payments incurred in attending the expected demand while satisfying network constraints. Disco can purchase energy either from the transmission network through the substations or from the DG units within its network. The DisCo minimization problem acts as a constraint into the each DG...
A bi-level approach for optimal contract pricing of independent dispatchable DG units in distribution networks
, Article International Transactions on Electrical Energy Systems ; Volume 26, Issue 8 , 2016 , Pages 1685-1704 ; 20507038 (ISSN) ; Rajabi Ghahnavieh, A ; Haghighat, H ; Sharif University of Technology
John Wiley and Sons Ltd
2016
Abstract
Distributed generation (DG) units are increasingly installed in the power systems. Distribution companies (DisCo) can opt to purchase the electricity from DG in an energy purchase contract to supply the customer demand and reduce energy loss. This paper proposes a framework for optimal contract pricing of independent dispatchable DG units considering competition among them. While DG units tend to increase their profit from the energy purchase contract, DisCo minimizes the demand supply cost. Multi-leader follower game theory concept is used to analyze the situation in which competing DG units offer the energy price to DisCo and DisCo determines the DG generation. A bi-level approach is used...
Simulation of earthquake records using time-varying ARMA (2,1) model
, Article Probabilistic Engineering Mechanics ; Volume 17, Issue 1 , 2001 , Pages 15-34 ; 02668920 (ISSN) ; Rofooei, F. R ; Ahmadi, G ; Sharif University of Technology
2001
Abstract
In this paper, the time-varying auto regressive moving average (ARMA) process is used as a simple yet efficient method for simulating earthquake ground motions. This model is capable of reproducing the nonstationary amplitude as well as the frequency content of the earthquake ground accelerations. The moving time-window technique is used to estimate the time variation of the model parameters from the actual earthquake records. The method is applied to synthesize the near field earthquakes, Naghan 1977, Tabas 1978, and Manjil 1990 recorded on dense soils in Iran, as well as the Mexico City 1985 earthquake recorded on a site with soft soil. It is shown that the selected ARMA (2,1) model and...
Investigation on the Influence of Cooling Rate on Microstructure of CuCr25% Melt-spun Alloy
, M.Sc. Thesis Sharif University of Technology ; Varahram, Nasser (Supervisor) ; Davami, Parviz (Supervisor)
Abstract
The Cu-Cr10% ingots were prepared in induction furnace and these ingots were used to prepare CuCr25% in VAR. The percentages of elements were checked by chemical analysis. The ingots were divided to slices with 20gr mass and these slices were put in quartz tubes. The quartz tubes were assembled in melt spinning machine and the ribbons were quenched onto a rotating copper wheel. Three different wheel speeds, 8, 16, 36 m/s were chosen. The microstructure of the ribbons was examined using a scanning electron microscopy (SEM). The relationship between wheel speed and thickness of the ribbons were compared with mathematical modeling. The disk of ribbons with thickness of 0.5mm and radius of 5mm...
Smart drug delivery: Capping strategies for mesoporous silica nanoparticles
, Article Microporous and Mesoporous Materials ; Volume 299 , 2020 ; Zare, H ; Razavi, S ; Mohammadi, H ; Torab Ahmadi, P ; Yazdani, N ; Bayandori, M ; Rabiee, N ; Izadi Mobarakeh, J ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Systematic delivery of therapeutic agents to specific sites, with a stimulus-responsive drug release profile is currently a rapidly growing area. Mesoporous silica nanoparticles (MSNs) are the useful platforms as drug/gene delivery systems due to their unique properties including the ability to control the pore size, high porosity, and morphology, which can directly affect the mechanism and profile of drug release. The appropriate fabrication strategy can tailor the particle shape and size, leading to enhanced delivery and release mechanisms. The MSN surface can be modified by using either organic or inorganic molecules to induce smart and site-specific drug delivery and release....