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    Modeling, simulation, and optimal initiation planning for needle insertion into the liver

    , Article Journal of Biomechanical Engineering ; Volume 132, Issue 4 , 2010 ; 01480731 (ISSN) Sharifi Sedeh, R ; Ahmadian, M. T ; Janabi Sharifi, F ; Sharif University of Technology
    2010
    Abstract
    Needle insertion simulation and planning systems (SPSs) will play an important role in diminishing inappropriate insertions into soft tissues and resultant complications. Difficulties in SPS development are due in large part to the computational requirements of the extensive calculations in finite element (FE) models of tissue. For clinical feasibility, the computational speed of SPSs must be improved. At the same time, a realistic model of tissue properties that reflects large and velocity-dependent deformations must be employed. The purpose of this study is to address the aforementioned difficulties by presenting a cost-effective SPS platform for needle insertions into the liver. The study... 

    Recent developments in dye-sensitized solar cells

    , Article ChemPhysChem ; Vol. 15, issue. 18 , Dec , 2014 , p. 3902-3927 Sharifi, N ; Tajabadi, F ; Taghavinia, N ; Sharif University of Technology
    2014
    Abstract
    The knowledge of dye-sensitized solar cells (DSCs) has expanded considerably in recent years. They are multiparameter and complex systems that work only if various parameters are tuned simultaneously. This makes it difficult to target to a single parameter to improve the efficiency. There is a wealth of knowledge concerning different DSC structures and characteristics. In this review, the present knowledge and recent achievements are surveyed with emphasis on the more promising cell materials and designs  

    Nanostructured silver fibers: Facile synthesis based on natural cellulose and application to graphite composite electrode for oxygen reduction

    , Article International Journal of Hydrogen Energy ; Volume 35, Issue 8 , 2010 , Pages 3258-3262 ; 03603199 (ISSN) Sharifi, N ; Tajabadi, F ; Taghavinia, N ; Sharif University of Technology
    2010
    Abstract
    The development of cheaper electrocatalysts for fuel cells is an important research area. This work proposes a new, simpler and low-cost approach to develop nanostructured silver electrocatalysts by using natural cellulose as a template. Silver was deposited by reduction of Ag complexes on the surface of cellulose fibers, followed by heat removal of the template to create self-standing nanostructured silver fibers (NSSFs). X-Ray diffraction (XRD) showed fcc silver phase and X-Ray photoelectron spectroscopy (XPS) demonstrated that the surface was partially oxidized. The morphology of the fibers consisted of 50 nm nanoparticles as the building blocks, and they possessed a specific surface area... 

    Robust composite nonlinear feedback control for spacecraft rendezvous systems under parameter uncertainty, external disturbance, and input saturation

    , Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; 2018 ; 09544100 (ISSN) Namdari, H ; Allahverdizadeh, F ; Sharifi, A ; Sharif University of Technology
    SAGE Publications Ltd  2018
    Abstract
    This paper presents a new robust composite nonlinear feedback control law for accurate, smooth, and fast regulation in the presence of parameter uncertainties, external disturbances, and input saturation for a class of spacecraft rendezvous systems. The novel proposed method consists of the original composite nonlinear feedback part for good transient performance plus a nonlinear disturbance rejection part for reducing the steady-state error stemming from variable disturbances and simultaneously producing feasible control input. The nonlinear disturbance rejection relies on sliding-mode observer for disturbance estimation. Closed-loop system stability has been proved with the Lyapunov... 

    Robust composite nonlinear feedback control for spacecraft rendezvous systems under parameter uncertainty, external disturbance, and input saturation

    , Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; Volume 234, Issue 2 , 2020 , Pages 143-155 Namdari, H ; Allahverdizadeh, F ; Sharifi, A ; Sharif University of Technology
    SAGE Publications Ltd  2020
    Abstract
    This paper presents a new robust composite nonlinear feedback control law for accurate, smooth, and fast regulation in the presence of parameter uncertainties, external disturbances, and input saturation for a class of spacecraft rendezvous systems. The novel proposed method consists of the original composite nonlinear feedback part for good transient performance plus a nonlinear disturbance rejection part for reducing the steady-state error stemming from variable disturbances and simultaneously producing feasible control input. The nonlinear disturbance rejection relies on sliding-mode observer for disturbance estimation. Closed-loop system stability has been proved with the Lyapunov... 

    On perturbation method in mechanical, thermal and thermo-mechanical loadings of plates: Cylindrical bending of FG plates

    , Article ZAMM Zeitschrift fur Angewandte Mathematik und Mechanik ; March , 2015 ; 00442267 (ISSN) Fallah, F ; Nosier, A ; Sharifi, M ; Ghezelbash, F ; Sharif University of Technology
    Wiley-VCH Verlag  2015
    Abstract
    The performance of perturbation method in nonlinear analyses of plates subjected to mechanical, thermal, and thermo-mechanical loadings is investigated. To this end, cylindrical bending of FG plates with clamped and simply-supported edges is considered. The governing equations of Mindlin's first-order shear deformation theory with von Kármán's geometric nonlinearity are solved using one- and two-parameter perturbation methods and the results are compared with the results of an analytical solution. The material properties are assumed to vary continuously through the thickness of the plate according to a power-law distribution of the volume fraction of the constituents. It is shown that the... 

    On perturbation method in mechanical, thermal and thermo-mechanical loadings of plates: Cylindrical bending of FG plates

    , Article ZAMM Zeitschrift fur Angewandte Mathematik und Mechanik ; Volume 96, Issue 2 , 2016 , Pages 217-232 ; 00442267 (ISSN) Fallah, F ; Nosier, A ; Sharifi, M ; Ghezelbash, F ; Sharif University of Technology
    Wiley-VCH Verlag  2016
    Abstract
    The performance of perturbation method in nonlinear analyses of plates subjected to mechanical, thermal, and thermo-mechanical loadings is investigated. To this end, cylindrical bending of FG plates with clamped and simply-supported edges is considered. The governing equations of Mindlin's first-order shear deformation theory with von Kármán's geometric nonlinearity are solved using one- and two-parameter perturbation methods and the results are compared with the results of an analytical solution. The material properties are assumed to vary continuously through the thickness of the plate according to a power-law distribution of the volume fraction of the constituents. It is shown that the... 

    Flow mediated dilation with photoplethysmography as a substitute for ultrasonic imaging

    , Article Physiological Measurement ; Volume 36, Issue 7 , 2015 , Pages 1551-1571 ; 09673334 (ISSN) Mashayekhi, G ; Zahedi, E ; Movahedian Attar, H ; Sharifi, F ; Sharif University of Technology
    Institute of Physics Publishing  2015
    Abstract
    Flow mediated dilation (FMD) is a non-invasive method for endothelial function assessment providing an index extracted from ultrasonic B-mode images. Although utilized in the research community, the difficulty of its application and high cost of ultrasonic devices prevent it from being widely used in clinical settings. In this study we show that substituting the ultrasonic device with more easily handled and low cost photoplethysmography and electrocardiography is possible. We introduce new indices based on the photoplethysmogram (PPG) and electrocardiogram (ECG) and show that they are correlated with the ultrasound-based FMD Index. To this end, a conventional ultrasound FMD test was carried... 

    Impact of cognition and cooperation on MAC layer performance metrics, part i: Maximum stable throughput

    , Article IEEE Transactions on Wireless Communications ; Volume 11, Issue 12 , 2012 , Pages 4252-4263 ; 15361276 (ISSN) Sharifi, A. A ; Ashtiani, F ; Keshavarz, H ; Nasiri Kenari, M ; Sharif University of Technology
    2012
    Abstract
    In this paper, we consider a broadband secondary transmitter-receiver pair which interferes with N narrowband primary users and study the effect of cognition and cooperation on the maximum stable throughput. In our study we focus on four transmission protocols as well as two channel types, i.e., flat fading and frequency selective fading. In the cooperative protocols, the broadband transmitter relays the packets of the primary users which have not correctly decoded at the primary receiver. The analysis includes random packet arrivals at the transmitters which may impact on the maximum stable throughput. Moreover, sensing errors at the secondary user are considered. In this paper, we derive... 

    The assessment of efficient representation of drug features using deep learning for drug repositioning

    , Article BMC Bioinformatics ; Volume 20, Issue 1 , 2019 ; 14712105 (ISSN) Moridi, M ; Ghadirinia, M ; Sharifi Zarchi, A ; Zare Mirakabad, F ; Sharif University of Technology
    BioMed Central Ltd  2019
    Abstract
    Background: De novo drug discovery is a time-consuming and expensive process. Nowadays, drug repositioning is utilized as a common strategy to discover a new drug indication for existing drugs. This strategy is mostly used in cases with a limited number of candidate pairs of drugs and diseases. In other words, they are not scalable to a large number of drugs and diseases. Most of the in-silico methods mainly focus on linear approaches while non-linear models are still scarce for new indication predictions. Therefore, applying non-linear computational approaches can offer an opportunity to predict possible drug repositioning candidates. Results: In this study, we present a non-linear method... 

    One-dimensional chemotaxis kinetic model

    , Article Nonlinear Differential Equations and Applications ; Volume 18, Issue 2 , 2011 , Pages 139-172 ; 10219722 (ISSN) Sharifi tabar, M ; Sharif University of Technology
    2011
    Abstract
    In this paper, we study a variation of the equations of a chemotaxis kinetic model and investigate it in one dimension. In fact, we use fractional diffusion for the chemoattractant in the Othmar-Dunbar-Alt system (Othmer in J Math Biol 26(3):263-298, 1988). This version was exhibited in Calvez in Amer Math Soc, pp 45-62, 2007 for the macroscopic well-known Keller-Segel model in all space dimensions. These two macroscopic and kinetic models are related as mentioned in Bournaveas, Ann Inst H Poincaré Anal Non Linéaire, 26(5):1871-1895, 2009, Chalub, Math Models Methods Appl Sci, 16(7 suppl):1173-1197, 2006, Chalub, Monatsh Math, 142(1-2):123-141, 2004, Chalub, Port Math (NS), 63(2):227-250,... 

    A novel niosome formulation for encapsulation of anthocyanins and modelling intestinal transport

    , Article Food Chemistry ; Volume 293 , 2019 , Pages 57-65 ; 03088146 (ISSN) Fidan Yardimci, M ; Akay, S ; Sharifi, F ; Sevimli Gur, C ; Ongen, G ; Yesil Celiktas, O ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    The bioavailability of drugs can be improved by regulating the structural properties, particularly lipoid systems, such as niosomes, can increase cellular uptake. Herein, we optimized double emulsion and niosomal formulations for encapsulating anthocyanin-rich black carrot extract. Nanoparticles obtained by selected formulation were characterized in terms of morphology, particle size, drug encapsulation efficiency, in vitro release and cytotoxicity. The optimum conditions for niosomal formulation were elicited as 30 mg of cholesterol, 150 mg of Tween 20 and feeding time of 1 min at a stirring rate of 900 rpm yielding the lowest average particle size of 130 nm. In vitro release data showed... 

    Investigating Effect of Nano Ceramic Coating of Combustion Chamber on the Performance of Internal Combustion Engines

    , M.Sc. Thesis Sharif University of Technology Sharifi, Masoud (Author) ; Naghdabadi, Reza (Supervisor)
    Abstract
    Thermal barrier coatings (TBCs) are used for increasing the efficiency and reducing pollutants of internal combustion engines (ICEs). In this paper, an optimization framework is developed in order to obtain the optimal dimensions for conventional coat, and the optimal dimensions and material property for functionally graded (FG) coat of a partially coated piston. A thermo mechanical analysis is investigated for Nano coat by finite element method. The conventional and Nano coats are made of MgZrO_3 as the insulating ceramic overlay and NiCrAl as the metallic bond-coat. The properties of the FG coat is assumed to vary according to power law through the thickness. For all tree conventional, FG... 

    Thermally Driven Exchange Flow Between Open Water and Floating Vegetation

    , M.Sc. Thesis Sharif University of Technology Sharifi, Elham (Author) ; Jamali, Mirmosadegh (Supervisor)
    Abstract
    In this thesis, we present the results of a laboratory and numerical model study of the exchange flow generated by the temperature gradient between an open water heated by sunlight and a canopy area made of floating vegetation. Particle Image Velocimetry is employed to obtain the structures of the warm flow intruding the canopy at the surface and the bottom cold return flow for different roots length and vegetation density. Following an initial, transient stage of flow build-up governed by a balance between inertia and buoyancy forces, the flow reaches a steady state in the canopy area with a force balance between buoyancy and vegetation drag dominating the flow within roots. At the steady... 

    Corrosion behaviour of Ni-Co alloy coatings at Kish Island (marine) atmosphere

    , Article Bulletin of Materials Science ; Vol. 37, issue. 3 , May , 2014 , p. 713-719 Sharifi, K ; Ghorbani, M ; Sharif University of Technology
    2014
    Abstract
    In this study, the corrosion behaviour of Ni-Co alloys with low Co content, electroplated on steel substrate in sulphate bath, was investigated. The morphology of coatings was studied by optical and SEM microscopy. The corrosion products were analyzed using EDX. The results showed that Ni-1%Co coatings had a better corrosion resistance 0.30, 0.92 and 3.75 mpy for atmospheric, salt spray and polarization tests, respectively. These are 0.41, 1.20 and 5.40 mpy for pure nickel coatings that indicate the least corrosion resistance. Surface analysis revealed the presence of oxides, sulphides and chlorides in corrosion products  

    plasma Electrolytic Oxidation of AZ31 in Silicate and Phosphate Electrolyte and Study of Corrosion Behavior

    , M.Sc. Thesis Sharif University of Technology Sharifi, Hassan (Author) ; Ghorbani, Mohammad (Supervisor)
    Abstract
    In recent years, magnesium and its alloys have been considered as biodegradable implants, but they corrode in the body before natural process of damaged organs recovery is completed. In this investigation PEO operation was used for corrosion control and effect of different parameter such as number of operation steps, electrolyte type, time and operation voltage on coating properties was studied. Scanning electron microscopy was used for investigating of morphology of coats and to determine chemical composition and phase of coats EDS analysis and X-ray diffraction were used. The corrosion resistance of samples were evaluated by potentiodynamic polarization and electrochemical impedance (EIS)... 

    Multiple model filters applied to wind model estimation for a fixed wing UAV

    , Article Proceedings of 2016 7th International Conference on Mechanical and Aerospace Engineering, ICMAE 2016, 18 July 2016 through 20 July 2016 ; 2016 , Pages 109-115 ; 9781467388290 (ISBN) Sharifi, A ; Nobahari, H ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    Abstract
    The flight of unmanned aerial vehicles is often associated with model uncertainties, measurement noises, and environmental disturbances such as wind gust. To mitigate these challenges, the accurate estimation of states is vital. Moreover, the wind model and its parameters should also be estimated and compensated during the flight. In this paper, a multiple model filter is implemented for this purpose. To investigate the performance of the multiple model filter, three different models including constant wind, '1-cosine' model and wind shear model are considered. The multiple model filter utilizes three extended Kalman filter to simultaneously estimate the model of wind, the parameters of the... 

    Nonlinear robust adaptive Cartesian impedance control of UAVs equipped with a robot manipulator

    , Article Advanced Robotics ; Volume 29, Issue 3 , Feb , 2015 , Pages 171-186 ; 01691864 (ISSN) Sharifi, M ; Sayyaadi, H ; Sharif University of Technology
    Robotics Society of Japan  2015
    Abstract
    In this paper, a new nonlinear robust adaptive impedance controller is addressed for Unmanned Aerial Vehicles (UAVs) equipped with a robot manipulator that physically interacts with environment. A UAV equipped with a robot manipulator is a novel system that can perform different tasks instead of human being in dangerous and/or inaccessible environments. The objective of the proposed robust adaptive controller is control of the UAV and its robotic manipulators end-effector impedance in Cartesian space in order to have a stable physical interaction with environment. The proposed controller is robust against parametric uncertainties in the nonlinear dynamics model of the UAV and the robot... 

    A Model for the Selection and Prioritization of Project Portfolio in the Project-Based Organizations

    , M.Sc. Thesis Sharif University of Technology Sharifi, Atefe (Author) ; Hajji, Alireza (Supervisor)
    Abstract
    During recent years a variety of decision making models for project selecting and priorities have been developed. Most of these models used quantitative indicators for projects evaluating and focused on financial and economic indicators. In this project, a decision support system for project portfolio management in construction industry has been developed. The most important feature of this model that distinct it from others is its relationship with the organization's strategies. On one hand, this model focuses on the organization to ensuring that the projects selected for investment, meet the portfolio strategy and on the other hand, it focuses on project management to delivering projects... 

    Silver nano-islands on glass fibers using heat segregation method

    , Article Materials Chemistry and Physics ; Volume 113, Issue 1 , 2009 , Pages 63-66 ; 02540584 (ISSN) Sharifi, N ; Taghavinia, N ; Sharif University of Technology
    2009
    Abstract
    A new method for fabrication of silver nano-islands on glass fibers using a top-down process is introduced. A thin layer of silver chemically coated on the surface of the glass fibers evolves into silver islands by heat treatment. The effect of the concentration of the initial solution and the temperature were investigated. Segregation was more clearly observed for lower solution concentrations and higher temperatures. The temperature of 500 °C was found optimum where separated islands form. At higher temperatures, the coagulation and burial of silver islands occur. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and diffused reflectance spectroscopy (DRS) were...