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    Shear-compression tests of URM walls: various setups and their influence on experimental results

    , Article Engineering Structures ; Volume 156 , February , 2018 , Pages 472-479 ; 01410296 (ISSN) Wilding, B. V ; Dolatshahi, K. M ; Beyer, K ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    Current design codes provide empirical equations for the drift capacity of unreinforced masonry (URM) walls that are based on results of quasi-static cyclic shear-compression tests. Yet different experimental campaigns have used various approaches of imposing fixed-fixed boundary conditions at the wall top which may affect the test results. This article investigates, by means of numerical simulations, the influence of experimental setups on the force and drift capacities of in-plane loaded URM walls subjected to double-fixed conditions. It is shown that controlling the shear span or the top rotation while keeping the axial force constant leads to very similar results. Controlling the axial... 

    A neuro-fuzzy approach to diagnosis of neonatal jaundice

    , Article 2006 1st Bio-Inspired Models of Network, Information and Computing Systems, BIONETICS, Madonna di Campiglio, 11 December 2006 through 13 December 2006 ; 2006 ; 1424404630 (ISBN); 9781424404636 (ISBN) Sohani, M ; Makki, B ; Sadati, N ; Kermani, K. K ; Riazati, A ; Sharif University of Technology
    2006
    Abstract
    This paper presents an approach that integrates clinical methods with Neuro-Fuzzy system in order to diagnose Neonatal Jaundice in newborns. First, a fuzzy logic system designed with medical rules to model the uncertainty that exists in medical diagnosis. Then a fuzzy neural network with an evolutionary learning helps the system to learn the new data gained from the patient and to help the fuzzy system to update itself in an online manner. By combining the aforementioned systems, the proposed approach can help physicians to diagnose jaundice with low risk cost associated with this disease. © 2006 IEEE  

    Newly designed ternary hematite-based heterojunction for PEC water splitting

    , Article Applied Surface Science ; Volume 550 , 2021 ; 01694332 (ISSN) Farhoosh, S ; Eftekharinia, B ; Tayebi, M ; Lee, B. K ; Naseri, N ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    Hematite is recognized as a promising photoanode for photoelectrochemical water oxidation to produce solar hydrogen due to its favorable properties. However, the high charge carrier recombination rate due to low electrical conductivity and sluggish oxygen reduction kinetics of pure hematite hinder its photocatalytic activity. This work proposed a new hematite-based heterostructure of Ti-Fe2O3/Fe2TiO5/FeOOH, synthesized through a hydrothermal method. The photoanode morphology was branched nanorods that expanded their surface area and improved charge transfer at the photoanode/electrolyte interface. In a novel and complement modification approach, a thin pseudobrookite interlayer was applied... 

    Experimental and theoretical study of the spectroscopic properties and the preparation of 3-benzyl-2H-pyrano[3,2-c]chromene-2,5(6H)-dione

    , Article Journal of Molecular Structure ; Vol. 1065-1066, issue. 1 , May , 2014 , pp. 235-240 ; ISSN: 00222860 Moghaddam, F. M ; Foroushani, B. K ; Sharif University of Technology
    2014
    Abstract
    Compound 3-benzyl-2H-pyrano[3,2-c]chromene-2,5(6H)-dione(3), was prepared and fully characterized. The vibrational modes (FT-IR) and NMR data ( 1H and 13C chemical shifts) were compared with the results of Density Functional Theory (DFT) method at the B3LYP/cc-PVTZ level. The calculated vibrational frequencies and NMR chemical shifts are in good agreement with the experimental results. The electronic (UV-Vis) spectrum was calculated using the TD-DFT method in CH2Cl2 with the Polarizable Continuum Model using the integral equation formalism variant (IEFPCM) and was correlated to the experimental spectra. The assignment and analysis of the frontier HOMO and LUMO orbitals indicate that... 

    Numerical investigations of hepatic spheroids metabolic reactions in a perfusion bioreactor

    , Article Frontiers in Bioengineering and Biotechnology ; Volume 7 , 2019 ; 22964185 (ISSN) Sharifi, F ; Firoozabadi, B ; Firoozbakhsh, K ; Sharif University of Technology
    Frontiers Media S.A  2019
    Abstract
    Miniaturized culture systems of hepatic cells are emerging as a strong tool facilitating studies related to liver diseases and drug discovery. However, the experimental optimization of various parameters involved in the operation of these systems is time-consuming and expensive. Hence, developing numerical tools predicting the function of such systems can significantly reduce the associated cost. In this paper, a perfusion-based three dimensional (3D) bioreactor comprising encapsulated human liver hepatocellular carcinoma (HepG2) spheroids are analyzed. The flow and mass transfer equations for oxygen as well as different metabolites such as albumin, glucose, glutamine, ammonia, and urea were... 

    Legendre polynomial expansion for analysis of linear one-dimensional inhomogeneous optical structures and photonic crystals

    , Article Journal of the Optical Society of America B: Optical Physics ; Volume 23, Issue 5 , 2006 , Pages 969-977 ; 07403224 (ISSN) Chamanzar, M ; Mehrany, K ; Rashidian, B ; Sharif University of Technology
    Optical Society of American (OSA)  2006
    Abstract
    A Legendre polynomial expansion of electromagnetic fields for analysis of layers with an inhomogeneous refractive index profile is reported. The solution of Maxwell's equations subject to boundary conditions is sought in a complete space spanned by Legendre polynomials. Also, the permittivity profile is interpolated by polynomials. Different cases including computation of reflection-transmission coefficients of inhomogeneous layers, band-structure extraction of one-dimensional photonic crystals whose unit-cell refractive index profiles are inhomogeneous, and inhomogeneous planar waveguide analysis are investigated. The presented approach can be used to obtain the transfer matrix of an... 

    Hermite polynomial expansion for analysis of electromagnetic slow waves in coupled nano conducting layer with Gaussian profile

    , Article LAPC 2007: 3rd Loughborough Antennas and Propagation Conference, Loughborough, 2 April 2007 through 3 April 2007 ; 2007 , Pages 265-268 ; 1424407761 (ISBN); 9781424407767 (ISBN) Sarrafi, P ; Mehrany, K ; Rashidian, B ; Sharif University of Technology
    2007
    Abstract
    The possibility of electromagnetic slow wave propagation in dielectric slab waveguides, when free two-dimensional interface charge layers are generated at film-substrate and film-cover interfaces, is already explored. In this paper, the propagation of electromagnetic slow waves supported by induced charge layers of nonzero thickness, whose induced charge densities have Gaussian profiles, is investigated for the first time. In order to analyze the effects of inhomogeneity in the conductivity profile, the electric field is expanded in terms of Hermite polynomials and each eigenmode is sought in the complete space spanned by them. © 2007 IEEE  

    Dynamic response of euler-Bernoulli, Timoshenko and higher-Order beams under a moving mass via RKPM

    , Article 7th European Conference on Structural Dynamics, EURODYN 2008, 7 July 2008 through 9 July 2008 ; 2008 ; 9780854328826 (ISBN) Nikkhoo, A ; Kiani, K ; Mehri, B ; Sharif University of Technology
    University of Southampton, Institute of Sound Vibration and Research  2008
    Abstract
    Discrete motion equations of an Euler-Bernoulli, Timoshenko and higher-order beams under a moving mass are derived for different boundary conditions. To this end, the reproducing kernel particle method (RKPM) has been utilized for spatial discretization, beside the extension of Newmark-β method for time discretization of the beams motion equations. The effects of significant parameters such as the beam's slenderness and velocity of the moving mass on the maximum deflection and bending moment of different beams are studied in some details. The results indicate the existence of a critical beam's slenderness mostly as a function of beam's boundary conditions, in which for slenderness lower than... 

    Three-dimensional diffraction analysis of gratings based on Legendre expansion of electromagnetic fields

    , Article Journal of the Optical Society of America B: Optical Physics ; Volume 24, Issue 10 , 2007 , Pages 2676-2685 ; 07403224 (ISSN) Khavasi, A ; Mehrany, K ; Rashidian, B ; Sharif University of Technology
    Optical Society of American (OSA)  2007
    Abstract
    Three-dimensional vectorial diffraction analysis of gratings is presented based on Legendre polynomial expansion of electromagnetic fields. In contrast to conventional rigorous coupled wave analysis (RCWA) in which the solution is obtained using state variables representation of the coupled wave amplitudes, here the solution of first-order coupled Maxwell's equations is expanded in terms of Legendre polynomials, where Maxwell's equations are analytically projected in the Hilbert space spanned by Legendre polynomials. This approach yields well-behaved algebraic equations for deriving diffraction efficiencies and electromagnetic field profiles without facing the problem of numerical... 

    Data compression technique for high resolution wireless photoplethysmograph recording system

    , Article International Conference on Space Science and Communication, IconSpace ; 2013 , Pages 345-349 ; 21654301 (ISSN) ; 9781467352314 (ISBN) Chong, K. S ; Zahedi, E ; Gan, K. B ; Mohd. Ali, M. A ; Sharif University of Technology
    2013
    Abstract
    Multi-site photoplethysmography is an optoelectronic technique that measures changes in blood volume associated with cardiac contraction. Photoplethysmogram (PPG) recording enables researchers to study the vascular and hemodynamic properties of human subjects. Currently, there is no commercial system available in the market to perform multi-channel PPG recording. The measurements can be obtained from fingertips, ear lobes and toes due to their low absorption and high degree of vasculature. The main objective of this project is to develop a suitable data compression algorithm for two-channel simultaneous high resolution wireless PPG recording system. MATLAB software was used during the... 

    Thermo- and pH-sensitive dendrosomes as bi-phase drug delivery systems

    , Article Nanomedicine: Nanotechnology, Biology, and Medicine ; Volume 9, Issue 8 , 2013 , Pages 1203-1213 ; 15499634 (ISSN) Adeli, M ; Fard, A. K ; Abedi, F ; Chegeni, B. K ; Bani, F ; Sharif University of Technology
    2013
    Abstract
    Fully supramolecular dendrosomes (FSD) as bi-phase drug delivery systems are reported in this work. For preparation of FSD, amphiphilic linear-dendritic supramolecular systems (ALDSS) have been synthesized by host-guest interactions between hyperbranched polyglycerol having β-cyclodextrin core and bi-chain polycaprolactone (BPCL) with a fluorescine focal point. Self-assembly of ALDSS in aqueous solutions led to FSD. They were able to encapsulate paclitaxel with a high loading capacity. The dendrosome-based drug delivery systems were highly sensitive to pH and temperature. They were stable at 20-37. °C and pH7-8, but dissociated and released drug at temperatures lower than 20. °C or higher... 

    Hot corrosion behavior and near-surface microstructure of a “low-temperature high-activity Cr-aluminide” coating on inconel 738LC exposed to Na2SO4, Na2SO4 + V2O5 and Na2SO4 + V2O5 + NaCl at 900 °C

    , Article Corrosion Science ; Volume 128 , 2017 , Pages 42-53 ; 0010938X (ISSN) Salehi Doolabi, M ; Ghasemi, B ; Sadrnezhaad, S. K ; Habibollahzadeh, A ; Jafarzadeh, K ; Sharif University of Technology
    2017
    Abstract
    Hot corrosion is a serious problem in gas turbines due to poor quality fuels which contain Na, V, S and Cl. To resolve the problem, Cr-aluminide was coated on IN-738LC superalloy with a two steps pack cementation process. Oxidation behavior and near-surface microstructure of the coating showed consecutive increase in destruction by exposition to Na2SO4, 75Na2SO4 + 25 V2O5 and 70Na2SO4 + 25 V2O5 + 5NaCl (wt.%). Kinetic studies indicated parabolic corrosion rate in salt-less samples due to diffusion. Similar expression for salt-covered samples was assessed for oxide dissolution. Plate-like, broken-plate-like and cauliflower-like morphologies attributed to the corrosion products were observed... 

    Evaluation and selection of optimal oxygen/fuel ratio for best mechanical properties, oxidation resistance and microstructure of HVOF NiCoCrAlY coatings using AHP–VIKOR method

    , Article Oxidation of Metals ; Volume 89, Issue 3-4 , April , 2018 , Pages 429-451 ; 0030770X (ISSN) Salehi Doolabi, M ; Ghasemi, B ; Sadrnezhaad, S. K ; Habibolahzadeh, A ; Jafarzadeh, K ; Sharif University of Technology
    Springer New York LLC  2018
    Abstract
    This work describes coating of NiCoCrAlY on IN-738LC superalloy by high-velocity oxygen fuel (HVOF) process. Properties of the coatings are significantly influenced by oxygen/fuel ratio and other spraying parameters. The effect of oxygen/fuel ratio on the oxidation behavior, bond strength, hardness, roughness and microstructure including porosity, inclusion formation and unmelted particles are discussed here. The porosity and inclusion in C1 coating are maximal. C2 coating with oxygen/fuel ratio of 2 has the highest bond strength and the lowest unmelted particles. C3 coating with the lowest total porosity and inclusion has the minimal roughness and the highest oxidation resistance and... 

    Evaluation and selection of optimal oxygen/fuel ratio for best mechanical properties, oxidation resistance and microstructure of HVOF NiCoCrAlY coatings using AHP–VIKOR method

    , Article Oxidation of Metals ; 2017 , Pages 1-23 ; 0030770X (ISSN) Salehi Doolabi, M ; Ghasemi, B ; Sadrnezhaad, S. K ; Habibolahzadeh, A ; Jafarzadeh, K ; Sharif University of Technology
    2017
    Abstract
    Abstract: This work describes coating of NiCoCrAlY on IN-738LC superalloy by high-velocity oxygen fuel (HVOF) process. Properties of the coatings are significantly influenced by oxygen/fuel ratio and other spraying parameters. The effect of oxygen/fuel ratio on the oxidation behavior, bond strength, hardness, roughness and microstructure including porosity, inclusion formation and unmelted particles are discussed here. The porosity and inclusion in C1 coating are maximal. C2 coating with oxygen/fuel ratio of 2 has the highest bond strength and the lowest unmelted particles. C3 coating with the lowest total porosity and inclusion has the minimal roughness and the highest oxidation resistance... 

    Aseptic loosening of femoral components - Materials engineering and design considerations

    , Article Materials and Design ; Volume 44 , February , 2013 , Pages 155-163 ; 02641275 (ISSN) Bahraminasab, M ; Sahari, B. B ; Edwards, K. L ; Farahmand, F ; Arumugam, M ; Sharif University of Technology
    2013
    Abstract
    Aseptic loosening is one of the main reasons for the revision of a total knee replacement (TKR). The design of the key component of a TKR, the femoral component, is particularly problematic because its failure can be the result of different causes. This makes the development of new biomaterials for use in the femoral component a challenging task. This paper focuses on the engineering design aspects in order to understand the limitationsof current materials and design deficiencies. The paper describes the introduction of a new biomaterial for a femoral component and justifies the recommendation to use multi-functional materials as a possible solution to aseptic loosening. The potential... 

    Experimental investigation on thermal performance of closed loop pulsating heat pipes with soluble and insoluble binary working fluids and a proposed correlation

    , Article Heat and Mass Transfer/Waerme- und Stoffuebertragung ; Volume 55, Issue 2 , 2019 , Pages 375-384 ; 09477411 (ISSN) Zamani, R ; Kalan, K ; Shafii, M. B ; Sharif University of Technology
    Springer Verlag  2019
    Abstract
    In this study, an experimental investigation was conducted from a thermal performance standpoint on closed-loop pulsating heat pipes (CLPHPs) with four different fluids and their water-based binary mixtures as working fluids with volume mixing ratios of 3:1, 1:1, and 1:3. Ethanol and acetone as two types of fluids that are soluble in water and, to unprecedentedly compare the behavior of insoluble mixtures with the soluble ones as the working fluids, toluene and hexane as two types that are insoluble in water were used. Additionally, to predict the thermal performance of the pure, soluble binary, and insoluble binary fluids simultaneously for the first time, a correlation was derived. © 2018,... 

    Experimental investigation on thermal performance of closed loop pulsating heat pipes with soluble and insoluble binary working fluids and a proposed correlation

    , Article Heat and Mass Transfer/Waerme- und Stoffuebertragung ; Volume 55, Issue 2 , February , 2019 , pp 375–384 ; 09477411 (ISSN) Zamani, R ; Kalan, K ; Shafii, M. B ; Sharif University of Technology
    Springer Verlag  2018
    Abstract
    In this study, an experimental investigation was conducted from a thermal performance standpoint on closed-loop pulsating heat pipes (CLPHPs) with four different fluids and their water-based binary mixtures as working fluids with volume mixing ratios of 3:1, 1:1, and 1:3. Ethanol and acetone as two types of fluids that are soluble in water and, to unprecedentedly compare the behavior of insoluble mixtures with the soluble ones as the working fluids, toluene and hexane as two types that are insoluble in water were used. Additionally, to predict the thermal performance of the pure, soluble binary, and insoluble binary fluids simultaneously for the first time, a correlation was derived. © 2018... 

    Improved differential-transfer-matrix method for inhomogeneous one-dimensional photonic crystals

    , Article Journal of the Optical Society of America B: Optical Physics ; Volume 23, Issue 7 , 2006 , Pages 1451-1459 ; 07403224 (ISSN) Eghlidi, M. H ; Mehrany, K ; Rashidian, B ; Sharif University of Technology
    Optical Society of American (OSA)  2006
    Abstract
    A band structure of one-dimensional periodic media having an arbitrary inhomogeneous refractive index profile is extracted based on the modification committed on the differential-transfer-matrix method (DTMM). Furthermore, the most recently modified differential transfer matrix is improved by reshaping the formulation in terms of which the electromagnetic fields are expanded and closed form formulas, providing the allowed values of Bloch wavenumbers, which were not available before. Although the frequency gaps in previously published results that we derived by using the conventional DTMM were not in agreement with the well-known Bragg law at the edge of each Brillouin zone, the new results... 

    Modified WKB method for solution of wave propagation in inhomogeneous structures with arbitrary permittivity and permeability profiles

    , Article 37th European Microwave Conference, EUMC, Munich, 9 October 2007 through 12 October 2007 ; December , 2007 , Pages 1373-1376 ; 9782874870033 (ISBN) Eghlidi, M. H ; Mehrany, K ; Rashidian, B ; Sharif University of Technology
    2007
    Abstract
    Modified forms of WKB expansion of electromagnetic field distribution with variable coefficients are proposed for both TE and TM polarizations. Based on a method similar to the previously reported differential transfer matrix method [1,2], the analytical expressions of those aforementioned coefficients are then derived. The applicability and accuracy of the presented method are shown via some numerical examples. © 2007 EuMA  

    Modified WKB method for solution of wave propagation in inhomogeneous structures with arbitrary permittivity and permeability profiles

    , Article European Microwave Week 2007, EuMW 2007 - 2nd European Microwave Integrated Circuits Conference, EuMIC 2007, Munich, 8 October 2007 through 12 October 2007 ; December , 2007 , Pages 575-578 ; 2874870021 (ISBN); 9782874870026 (ISBN) Eghlidi, M. H ; Mehrany, K ; Rashidian, B ; Sharif University of Technology
    2007
    Abstract
    Modified forms of WKB expansion of electromagnetic field distribution with variable coefficients are proposed for both TE and TM polarizations. Based on a method similar to the previously reported differential transfer matrix method [1,2], the analytical expressions of those aforementioned coefficients are then derived. The applicability and accuracy of the presented method are shown via some numerical examples. © 2007 EuMA