A priority of Logic

, M.Sc. Thesis Sharif University of Technology Bagheri, Mehdi (Author) ; Nasrin, Mehdi (Supervisor)

Abstract

Hartry Field argues that meaning-besed approaches to explaining the apriority of certain propositions fail to succeed in their endeavour. He suggests that adoting what one cals a non-factualist view of justification itself removes the mystery of the apriority of such propositions, and sketches what such a view of justification involves. A priori justification is often thought mysterious or out of keeping with a naturalistic view of the world; strong forms of priori justification that involve empirical indefeasibility are often thought especially mysterious. While this is no doubt correct for excessive claims of a priority – for instance, claims to prori acces to features of the physical...

Design and Fabrication of Inductive High Temperature Superconducting Fault Current Limiter

, Ph.D. Dissertation Sharif University of Technology Hekmati, Arsalan (Author) ; Vakilian, Mehdi (Supervisor) ; Fardmanesh, Mehdi (Supervisor)

Abstract

The continuous rise in electricity demand and the ever growing power generation in different power networks over the world have caused the short circuit level in the power systems to exceed the operational rating of the installed power devices (including cables, circuit breakers and buses). Replacing these devices with new higher rating devices is an expensive solution. From this point of view, utilizing fault current limiters is an economical solution. Superconducting fault current limiters form an efficient category of current limiters. This type is expected to be studied and used widely in future due to their advantages. In this thesis, the first chapter reviews the superconductivity...

, M.Sc. Thesis Sharif University of Technology Mardiha, Milad (Author) ; Vakilian, Mehdi (Supervisor) ; Fardmanesh, Mehdi (Supervisor)

Selective synthesis of conjugated enynes from α-arylalkynols using LiCl-Acidic Al2O3 under solvent-free conditions [electronic resource]

, Article Journal of Chemical Research ; Volume 2002, Number 8, 1 August 2002, pp. 378-380(3) Pourjavadi, A. (Ali) ; Bagheri Marandi, Gholam

Abstract

Free Content Selective synthesis of conjugated enynes from α-arylalkynols using LiCl-Acidic Al2O3 under solvent-free conditions

Selective preparation of fluorescent 1,8-naphthalimides using acidic alumina under microwave irradiation [electronic resource]

, Article Journal of Chemical Research ; 01/2001; 2001(11):485-487 Pourjavadi, A. (Ali) ; Bagheri Marandi, Gholam

Abstract

7H-benzimidazo[2,1-a]benz[de]isoquinolin-7-one compounds were prepared in a selective manner by reaction between o-phenylenediamines and appropriate 1,8-naphthalenedicarboxylic anhydrides using acidic alumina under microwave irradiation

Free vibration of joined cylindrical–hemispherical FGM shells

, Article Archive of Applied Mechanics ; Volume 90, Issue 10 , 2020 , Pages 2185-2199 Bagheri, H ; Kiani, Y ; Bagheri, N ; Eslami, M. R ; Sharif University of Technology

Springer 2020

Abstract

Free vibration response of a joined shell system including cylindrical and spherical shells is analyzed in this research. It is assumed that the system of joined shell is made from a functionally graded material (FGM). Properties of the shells are assumed to be graded through the thickness. Both shells are unified in thickness. To capture the effects of through-the-thickness shear deformations and rotary inertias, first-order shear deformation theory of shells is used. The Donnell type of kinematic assumptions is adopted to establish the general equations of motion and the associated boundary and continuity conditions with the aid of Hamilton’s principle. The resulting system of equations is...

Free vibrations of functionally graded material cylindrical shell closed with two spherical caps

, Article Ships and Offshore Structures ; 2021 ; 17445302 (ISSN) Bagheri, H ; Kiani, Y ; Bagheri, N ; Eslami, M. R ; Sharif University of Technology

Taylor and Francis Ltd 2021

Abstract

Free vibration response of a cylindrical shell closed with two hemispherical caps at the ends (hermit capsule) is analysed in this research. It is assumed that the system of joined shell is made from functionally graded materials (FGM). Properties of the shells are assumed to be graded through the thickness. Cylindrical and hemispherical shells are unified in thickness. To capture the effects of through-the-thickness shear deformations and rotary inertias, first order theory of shells is used. Donnell type of kinematic assumptions are adopted to establish the general equations of motion and the associated boundary and continuity conditions with the aid of Hamilton's principle. The resulting...

Free vibrations of functionally graded material cylindrical shell closed with two spherical caps

, Article Ships and Offshore Structures ; Volume 17, Issue 4 , 2022 , Pages 939-951 ; 17445302 (ISSN) Bagheri, H ; Kiani, Y ; Bagheri, N ; Eslami, M. R ; Sharif University of Technology

Taylor and Francis Ltd 2022

Abstract

Free vibration response of a cylindrical shell closed with two hemispherical caps at the ends (hermit capsule) is analysed in this research. It is assumed that the system of joined shell is made from functionally graded materials (FGM). Properties of the shells are assumed to be graded through the thickness. Cylindrical and hemispherical shells are unified in thickness. To capture the effects of through-the-thickness shear deformations and rotary inertias, first order theory of shells is used. Donnell type of kinematic assumptions are adopted to establish the general equations of motion and the associated boundary and continuity conditions with the aid of Hamilton's principle. The resulting...

A metal-organic framework sustained by a nanosized Ag12 cuboctahedral node for solid-phase extraction of ultra traces of lead(II) ions

, Article Microchimica Acta ; Vol. 181, issue. 9-10 , 2014 , pp. 999-1007 ; ISSN: 0026-3672 Salarian, M ; Ghanbarpour, A ; Behbahani, M ; Bagheri, S ; Bagheri, A ; Sharif University of Technology

2014

Abstract

We show that a metal-organic framework (MOF) sustained by a nanosized Ag12 cuboctahedral node can be applied to selectively extract traces of lead(II) ion from environmental water samples. The MOF was characterized by thermogravimetric and differential thermal analysis, scanning electron microscopy, FTIR, and X-ray diffraction. The effects of pH value, flow rates, of type, concentration and volume of the eluent, of break-through volume and potentially interfering ions on the separation and determination of lead were evaluated. Following desorption with EDTA, Pb(II) was quantified by FAAS. The use of the MOF results in excellent analytical figures of merit including an analytical range from 2...

Enhancement of THz Radiation from Josephson Junctions in Superconductors Using Electromagnetic Resonators

, M.Sc. Thesis Sharif University of Technology Iranmehr, Masoud (Author) ; Ahmadi Boroujeni, Mehdi (Supervisor) ; Fardmanesh, Mehdi (Supervisor)

Abstract

Terahertz waves which includes frequencies between 100 GHz to 10 THz of electromagnetic spectrum have found many applications in science, medical treatments and industry. One of the recent methods to produce these waves is using nonlinear properties of superconductors based on Josephson junctions which inherently appear in some superconductors called BSCCO. Stack of intrinsic junctions of these superconducting materials can radiate terahertz waves by only applying a DC voltage across them. This Thesis investigates some of these structures based on Josephson junctions to produce coherent radiation of terahertz waves. For the optimization of the radiation power, this study also investigates...

On the Spectrum of Modified Theories of Gravity

, M.Sc. Thesis Sharif University of Technology Seraj, Ali (Author) ; Golshani, Mehdi (Supervisor) ; Sheikh Jabbari, Mohammad Mehdi (Supervisor)

Abstract

There are different approaches in modifications of General Relativity as the theory of gravity. The modified theories of gravity are important cases in this context, which mostly start by modifying the Einstein-Hilbert action, while keeping the general covariance. Within the modified theories of gravity, we consider two cases. The first is the f(R) theories of gravity, and the second is curvature squared theories of gravity with an action like S = ∫d4x pg( 116GR + (R)2 + R2 +(R)2). Curvature squared theories of gravity have interesting feautures, most important of which is renormalizability, in contrast with General Relativity. But this advantage, as noted by K.S. Stelle in 1977 comes at...

On Thermodynamics and Phase Space of Near Horizon Extremal Geometries

, Ph.D. Dissertation Sharif University of Technology Hajian, Kamal (Author) ; Sheikh-Jabbari, Mohammad Mehdi (Supervisor) ; Golshani, Mehdi (Co-Advisor)

Abstract

Near Horizon Extremal Geometries (NHEG), are geometries which may appear in the near horizon region of the extremal black holes. These geometries have SL(2;R)U(1)n isometry, and constitute a family of solutions to the theory under consideration. In the first part of this report,their thermodynamic properties are reviewed, and their three universal laws are derived. In addition, at the end of the first part, the role of these laws in black hole thermodynamics is presented. In the second part of this thesis, we review building their classical phase space in the Einstein-Hilbert theory. The elements in the NHEG phase space manifold are built by appropriately chosen coordinate transformations of...

Critique and Survey of Various Formulation of Multiverse Theory

, Ph.D. Dissertation Sharif University of Technology Masoumi, Saeed (Author) ; Golshani, Mehdi (Supervisor) ; Sheikh Jabbari, Mohammad Mehdi (Supervisor)

Abstract

Multiverse scenario has been recently addressed by physicists and they have found it useful in many areas of physics. In this dissertation, I have treated some issues about multiverse such as the kinds of multiverses, the arguments for or against multiverse, areas in which multiverse is introduced, etc. This dissertation has six chapters and an appendix. In the chapter one, some classifications of multiverse is introduced, and also some definitions of the concept of a world is presented. Then, my classification and definition of a multiverse and a world is introduced. In the chapter two, the concept of possible worlds in philosophy and its relationship with multiverse hypothesis is examined....

Optimal Multicriteria Design of HTS Transformer and Construction of a Laboratory Scale Sample

, Ph.D. Dissertation Sharif University of Technology Moradnouri, Ahmad (Author) ; Vakilian, Mehdi (Supervisor) ; Fardmanesh, Mehdi (Co-Supervisor) ; Hekmati, Arsalan (Co-Supervisor)

Abstract

Employing high-temperature superconducting (HTS) tapes, instead of copper or aluminum wires for winding in a superconducting transformer, results in a series of significant advantages; such as: smaller volume, lighter weight, higher efficieny, greatly extended overload capability, better voltage regulation, lower life cycle cost, fault current limiting capability, lower environmental pollution and lower risk potential against fire hazards.In this thesis, optimal design of flux diverter using genetic algorithm for axial short circuit force reduction in HTS transformers has been performed. Then, multilayered flux diverters have been proposed for reduction of weight and losses. The impact of...

Cerebrovascular Attack Detection Using Artificial Intelligent Neural Network

, M.Sc. Thesis Sharif University of Technology Bagheri, Mahdi (Author) ; Bagheri Shouraki, Saeed (Supervisor) ; Haj Sadeghi, Khosrow (Co-Advisor)

Abstract

Cerebrovascular Attack has been ranked the second or third of top 10 death causes in Taiwan. It has caused about 13,000 deaths every year since 1986. Once Cerebrovascular Attack (CVA) occurs, it not only leads to the huge cost of medical care, but even death. All developed countries in the world put CVA prevention and treatment in high priority. However, it is necessary to build a detective model to enhance the accurate diagnosis of CVA. From this detective model, CVA classiﬁcation rules were extracted and used to improve the diagnosis and detection of CVA. This study acquired 2449 valid samples from this CVA prevention and treatment program, and adopted three classiﬁcation algorithms,...

The effect of reinforcement percentages on properties of copper matrix composites reinforced with TiC particles

, Article Journal of Alloys and Compounds ; Volume 676 , 2016 , Pages 120-126 ; 09258388 (ISSN) Bagheri, Gh. A ; Sharif University of Technology

Elsevier Ltd 2016

Abstract

In this research, copper matrix composites reinforced with different amounts of titanium carbide particles were produced by mechanical milling and in-situ formation of reinforcements. Morphology and size of milled powders were inspected by scanning electron microscopy (SEM) several times during milling process. Changes in lattice parameter, crystallite size, lattice strain, dislocation density and Gibbs free energy changes (due to increasing in dislocation densities and grain boundaries) in different samples (with different TiC particles contents) were studied by X-Ray Diffraction technique with Cu-kα radiation and using Nelson-Riley method and Williamson-Hall equation. Microstructure of...

A Multi-Objective Robust Optimization Model for Logistics Planning in the Earthquake Response Phase [electronic resource]

, Article Transportation Research Part E: Logistics and Transportation Review, Elsevier ; Volume 49, Issue 1, January 2013, , Pages 217–249 Najafi, M. (Mehdi) ; Eshghi, Kourosh ; Dullaert, Wout ; Sharif University of Technology

Abstract

Usually, resources are short in supply when earthquakes occur. In such emergency situations, disaster relief organizations must use these scarce resources efficiently to achieve the best possible emergency relief. This paper therefore proposes a multi-objective, multi-mode, multi-commodity, and multi-period stochastic model to manage the logistics of both commodities and injured people in the earthquake response. Also, a robust approach is developed and used to make sure that the distribution plan performs well under the various situations that can follow an earthquake. Afterwards, it proposes a solution methodology according to hierarchical objective functions and uses it to illustrate the...

Monitoring of Valve Leakage in Internal Combustion Engine Using Acoustic Emission Method

, Ph.D. Dissertation Sharif University of Technology Jafari, Mohammad (Author) ; Behzad, Mehdi (Supervisor) ; Mehdigholi, Hamid (Supervisor) ; Ahmadi, Mohammad Mehdi (Co-Advisor)

Abstract

Valve leak detection is very important due to bad direct effects on parts life and engine power. Acoustic emission (AE) has a good known ability on leak detection between fault detection methods. The aim of this thesis is presenting the ability of AE method for valve leak detection in internal combustion engines. The research method in a general framework based on the idea that firstly some evaluations were done in static tests for leakage due to three faults including clearance, quasi-crack and notch. Then, the evaluations were continued with dynamic analysis of rotational speeds and different loads on the engine. Finally, the neural network approach was used to automatically detect all...

Size tuning of Ag‐decorated TiO2 nanotube arrays for improved bactericidal capacity of orthopedic implants [electronic resource]

, Article Journal of Biomedical Materials Research Part A ; Auguest 2014, Vol. 102, Issue 8, P.2625-35 Esfandiari, N ; Simchi, A. (Abdolreza) ; Bagheri, R ; Sharif University of Technology

Abstract

Surface modification of orthopedic implants using titanium dioxide nanotubes and silver nanoparticles (SNs) is a promising approach to prevent bacteria adhesion, biofilm formation, and implant infection. Herein, we utilized a straightforward and all-solution process to prepare silver-decorated TiO2 nanotube arrays with surface density of 10(3) to 10(4) per µm(2). With controlling the synthesis conditions, hexagonal closed-packed nanotubes with opening diameter of 30-100 nm that are decorated with SNs with varying sizes (12-40 nm) were prepared. Various analytical techniques were utilized to characterize the size, morphology, distribution, valance state, surface roughness, and composition of...

Evaluation of Electromagnetic Forces on three-phase Core-Type Power Transformer Windings during Inrush Current by FEM

, M.Sc. Thesis Sharif University of Technology Eslami, Ali (Author) ; Vakilian, Mehdi (Supervisor)

Abstract

Inrush Current is a form of over-current that occurs during energization of a transformer. For power transformers, the magnitude of the first peak of inrush current is initially several times the rated load current but slowly decreases until it finally reaches the normal exciting current value. This process typically takes several minutes. Time-variant axial and radial electromagnetic forces under inrush current and short-circuit current are calculated (by finite element method; FEM), and compared. An analytic method is presented for computation of inrush current in transformer. The simulation results obtained by this proposed method are compared with the measured values. A compact...