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    Comparison of synthesis and purification of carbon nanotubes by thermal chemical vapor deposition on the nickel-based catalysts: NiSio2 and 304-type stainless steel

    , Article Journal of Applied Sciences ; Volume 10, Issue 9 , 2010 , Pages 716-723 ; 18125654 (ISSN) Fekri, L ; Jafari, A ; Fekri, S ; Shafikhani, A ; Vesaghi, M ; Behzadi, G ; Sharif University of Technology
    2010
    Abstract
    In this study by Thermal Chemical Vapor Deposition (TCVD) method, the synthesis of carbon nanotubes (CNTs) and temperature affects on the grown CNTs on the NiSio2 catalyst and 304-type stainless steel was investigated. The purification of the grown CNTs on the 304-type stainless steel was also investigated in this study. The synthesis and purification of the samples were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), termogravimetric analysis (TGA) and Raman spectroscopy. Our obtained result by SEM and TEM shows that densities of CNTs growth on the 304-type stainless steel are more than the CNTs growth on the NiSio2 catalyst and both of them have... 

    Angle of attack estimation and aircraft controller design using LQR methods

    , Article Canadian Conference on Electrical and Computer Engineering 2005, Saskatoon, SK, 1 May 2005 through 4 May 2005 ; Volume 2005 , 2005 , Pages 2253-2256 ; 08407789 (ISSN) Fekri, M. Z ; Mobed, M ; Sharif University of Technology
    2005
    Abstract
    An LQ-based tracker is designed in this paper, using output feedback. For performing the design, at first, a structured controller is introduced for a set of equations. The controller is obtained by mini-mizing a cost function which has some penalties on both the system's inputs and states. After that, an estimator is introduced and combined with the controller to close the loop. Running the nonlinear simulation at the end verifies the superiority of Extended Kalman Estimator (EKF)to the Linear Kalman Estimator (LKF). © 2005 IEEE  

    On the capacity of level and type modulations in Molecular communication with ligand receptors

    , Article IEEE International Symposium on Information Theory - Proceedings, 14 June 2015 through 19 June 2015 ; Volume 2015-June , 2015 , Pages 1951-1955 ; 21578095 (ISSN) ; 9781467377041 (ISBN) Aminian, G ; Mirmohseni, M ; Nasiri Kenari, M ; Fekri, F ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015
    Abstract
    In this paper, we consider the bacterial point-to-point communication problem with one transmitter and one receiver by considering the ligand receptor binding process. The most commonly investigated signalling model, referred to as the Level Scenario (LS), uses one type of a molecule with different concentration levels for signaling. An alternative approach is to employ multiple types of molecules with a single concentration level, referred to as the Type Scenario (TS). We investigate the trade-offs between the two scenarios for the ligand receptor from the capacity point of view. For this purpose, we evaluate the capacity using numerical algorithms. Moreover, we derive an upper bound on the... 

    On Zero Divisor Graphs

    , M.Sc. Thesis Sharif University of Technology Fekri Dabanloo, Yousef (Author) ; Mahdavi Hezavehi, Mohammad (Supervisor)
    Abstract
    We survey the research conducted on zero divisor graphs, with a focus on zero divisor graphs determined by equivalence classes of zero divisors of a commutative ring R. In particular, we consider the problem of classifying star graphs with any finite number of vertices. We study the pathology of a zero divisor graph in terms of cliques, we investigate when the clique and chromatic numbers are equal, and we show that the girth of a Noetherian ring, if finite, is 3. We also introduce a graph for modules that is useful for studying zero divisor graphs of trivial extensions  

    Finite Element Analysis of Reinforced Concrete Waffle Slabs in Steel Structures “Strength Conditions”

    , M.Sc. Thesis Sharif University of Technology Fekri, Mohsen (Author) ; Eskandari, Morteza (Supervisor) ; Kazemi, Mohamad Taghi (Supervisor)
    Abstract
    Building weight reducing idea and implementation of Lightweight Structures were always attractive for structural engineering experts, scholars and researchers around the world and its proven effects on improving behavior and reducing the forces acting on the structure, has urged researchers to create new designs. Concrete slabs are of a significant portion of the overall weight of the structure. Nowadays, waffle slabs are a demand for structural designers, as a consequence of architectural design evolution and new building management concepts, in spite of its laborious numerical modeling. The objective of this work was to analyze the adequacy of a design method widely used in the modeling of... 

    Impact of rock mineralogy on reservoir souring: A geochemical modeling study

    , Article Chemical Geology ; Volume 555 , November , 2020 Li, H ; Zhang, L ; Liu, L ; Shabani, A ; Sharif University of Technology
    Elsevier B. V  2020
    Abstract
    The petroleum industry suffers from reservoir souring phenomena, which has negative impacts on production facilities, health, and environment. Injection of incompatible water into the reservoir (waterflooding), which is considered as an enhanced oil recovery (EOR) method, is one of the most common causes of reservoir souring. In general, injected brine, especially seawater, contains high amounts of sulfate ion (SO42−). A high concentration of sulfate in the presence of sulfate-reducing bacteria (SRB) leads to the microbial reservoir souring. During this phenomenon, sulfide, specifically hydrogen sulfide gas (H2S) appears in the producing fluid of the reservoir. In this paper, a coupled... 

    A mechanobiological mathematical model of liver metabolism

    , Article Biotechnology and Bioengineering ; Volume 117, Issue 9 , 5 June , 2020 , Pages 2861-2874 Nikmaneshi, M. R ; Firoozabadi, B ; Munn, L. L ; Sharif University of Technology
    John Wiley and Sons Inc  2020
    Abstract
    The liver plays a complex role in metabolism and detoxification, and better tools are needed to understand its function and to develop liver-targeted therapies. In this study, we establish a mechanobiological model of liver transport and hepatocyte biology to elucidate the metabolism of urea and albumin, the production/detoxification of ammonia, and consumption of oxygen and nutrients. Since hepatocellular shear stress (SS) can influence the enzymatic activities of liver, the effect of SS on the urea and albumin synthesis are empirically modeled through the mechanotransduction mechanisms. The results demonstrate that the rheology and dynamics of the sinusoid flow can significantly affect... 

    cis-Dioxo-molybdenum(VI)-oxazoline complex catalyzed epoxidation of olefins by tert-butyl hydrogen peroxide

    , Article Inorganica Chimica Acta ; Volume 362, Issue 10 , 2009 , Pages 3698-3702 ; 00201693 (ISSN) Bagherzadeh, M ; Tahsini, L ; Latifi, R ; Keith Woo, L ; Sharif University of Technology
    2009
    Abstract
    A new efficient catalytic system was investigated for the epoxidation of various olefins by cis-dioxo-bis[2-(2′-hydroxyphenyl)-oxazolinato]molybdenum(VI), cis-[MoO2(phox)2], and TBHP as oxidizing agent. Using this system as catalyst for the oxidation of aliphatic substrates at 80 °C gives the epoxide as the sole product with yields up to 100% and turnover frequency up to 5000 h-1. The efficiency of the catalyst is strongly influenced by the nature of solvent, reaction time and temperature, and a significant increase in the epoxide yields is observed in higher temperatures and longer reaction times. © 2009 Elsevier B.V  

    Computational simulations of tumor growth and treatment response: Benefits of high-frequency, low-dose drug regimens and concurrent vascular normalization

    , Article PLoS Computational Biology ; Volume 19, Issue 6 June , 2023 ; 1553734X (ISSN) Nikmaneshi, M. R ; Jain, R. K ; Munn, L. L ; Sharif University of Technology
    Public Library of Science  2023
    Abstract
    Implementation of effective cancer treatment strategies requires consideration of how the spatiotemporal heterogeneities within the tumor microenvironment (TME) influence tumor progression and treatment response. Here, we developed a multi-scale three-dimensional mathematical model of the TME to simulate tumor growth and angiogenesis and then employed the model to evaluate an array of single and combination therapy approaches. Treatments included maximum tolerated dose or metronomic (i.e., frequent low doses) scheduling of anti-cancer drugs combined with anti-angiogenic therapy. The results show that metronomic therapy normalizes the tumor vasculature to improve drug delivery, modulates... 

    Is negative attention better than no attention? The comparative effects of ostracism and harassment at work

    , Article Organization Science ; Volume 26, Issue 3 , 2015 , Pages 774-793 ; 10477039 (ISSN) O'Reilly, J ; Robinson, S. L ; Berdahl, J. L ; Banki, S ; Sharif University of Technology
    INFORMS Inst.for Operations Res.and the Management Sciences  2015
    Abstract
    Ostracism has been recognized as conceptually and empirically distinct from harassment. Drawing from theory and research that suggests that employees have a strong need to belong in their organizations, we examine the comparative frequency and impact of ostracism and harassment in organizations across three field studies. Study 1 finds that a wide range of employees perceive ostracism, compared with harassment, to be more socially acceptable, less psychologically harmful, and less likely to be prohibited in their organization. Study 2 surveyed employees from a variety of organizations to test our theory that ostracism is actually a more harmful workplace experience than harassment.... 

    Dielectrophoretic cell sorting via sliding cells on 3D silicon microelectrodes

    , Article Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS), 22 January 2017 through 26 January 2017 ; 2017 , Pages 147-150 ; 10846999 (ISSN) ; 9781509050789 (ISBN) Xing, X ; Chan, M. L ; Roshan, K. A ; Yobas, L ; Sharif University of Technology
    2017
    Abstract
    This work presents an innovative design for a flow-through dielectrophoretic cell sorting based on silicon bulk microelectrodes featuring sidewall undercuts. The microelectrodes are configured into an interdigitated array with digits extending across the flow chamber at an oblique angle against the flow stream. Target cells under dielectrophoretic forces and hydrodynamic drag can slide along the digits to a dedicated outlet. The design has been showcased for continuous-flow sorting of viable and non-viable mammalian cells, achieving a throughput of 16,600 cells/min, an order of magnitude higher than those reported for existing continuous-flow cell sorting designs using thin-film or... 

    A multi-scale model for determining the effects of pathophysiology and metabolic disorders on tumor growth

    , Article Scientific Reports ; Volume 10, Issue 1 , 20 February , 2020 Nikmaneshi, M. R ; Firoozabadi, B ; Mozafari, A ; Munn, L. L ; Sharif University of Technology
    Nature Research  2020
    Abstract
    The search for efficient chemotherapy drugs and other anti-cancer treatments would benefit from a deeper understanding of the tumor microenvironment (TME) and its role in tumor progression. Because in vivo experimental methods are unable to isolate or control individual factors of the TME and in vitro models often do not include all the contributing factors, some questions are best addressed with systems biology mathematical models. In this work, we present a new fully-coupled, agent-based, multi-scale mathematical model of tumor growth, angiogenesis and metabolism that includes important aspects of the TME spanning subcellular-, cellular- and tissue-level scales. The mathematical model is... 

    Deviatoric stress response envelopes from multiaxial tests on sand

    , Article Solid Mechanics and its Applications ; Volume 146 , 2007 , Pages 253-262 ; 09250042 (ISSN); 9781402061455 (ISBN) Wood, D. M ; Sadek, T ; Dihoru, L ; Lings, M. L ; Sharif University of Technology
    Springer Verlag  2007
    Abstract
    Sets of rosettes of stress probes have been performed on Hostun sand in a flexible boundary true triaxial apparatus. These have shown the effect of stress history on the local distortional stiffness of the sand. Histories have included isotropic compression, and deviatoric paths with increasingly complex shapes. These tests were performed and interpreted against a background of kinematic hardening and bounding surface plasticity, using stress response envelopes to reveal evolving distortional stiffness. Use of response envelopes to study volumetric stiffness appears to be less helpful but the phase transformation surfaces that can be extracted seem somewhat independent of recent stress... 

    Gas chromatography with atomic emission detection: A powerful technique

    , Article TrAC - Trends in Analytical Chemistry ; Volume 21, Issue 9-10 , 2002 , Pages 618-626 ; 01659936 (ISSN) Van Stee, L. L. P ; Brinkman, U. A.Th ; Bagheri, H ; Sharif University of Technology
    Elsevier  2002
    Abstract
    Atomic emission detection (AED) is a sensitive as well as a selective detection technique for gas chromatography (GC) and provides element-specific information. A rapidly increasing number of applications in many different areas illustrates the versatility and analytical power of the technique - especially when complex samples have to be analysed. The complementary use of GC-AED and GC with mass-spectrometric detection often yields the most rewarding results. © 2002 Published by Elsevier Science B.V. All rights reserved  

    A state-of-the-art model for spatial and stochastic oil spill risk assessment: A case study of oil spill from a shipwreck

    , Article Environment International ; Volume 126 , 2019 , Pages 309-320 ; 01604120 (ISSN) Amir Heidari, P ; Arneborg, L ; Lindgren, J. F ; Lindhe, A ; Rosén, L ; Raie, M ; Axell, L ; Hassellöv, I. M ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    Oil spills are serious environmental issues that potentially can cause adverse effects on marine ecosystems. In some marine areas, like the Baltic Sea, there is a large number of wrecks from the first half of the 20th century, and recent monitoring and field work have revealed release of oil from some of these wrecks. The risk posed by a wreck is governed by its condition, hazardous substances contained in the wreck and the state of the surrounding environment. Therefore, there is a need for a common standard method for estimating the risks associated with different wrecks. In this work a state-of-the-art model is presented for spatial and stochastic risk assessment of oil spills from... 

    Polymer-Supported Bis-1,2,4-triazolium ionic tag framework for an efficient Pd(0) catalytic system in biomass derived γ-valerolactone

    , Article ACS Sustainable Chemistry and Engineering ; Volume 7, Issue 7 , 2019 , Pages 6939-6946 ; 21680485 (ISSN) Valentini, F ; Mahmoudi, H ; Bivona, L. A ; Piermatti, O ; Bagherzadeh, M ; Fusaro, L ; Aprile, C ; Marrocchi, A ; Vaccaro, L ; Sharif University of Technology
    American Chemical Society  2019
    Abstract
    A resin-bound 1,2,4-triazolium ionic tag has been used as support for the preparation of solid palladium nanoparticles (Pd(0)-POLI-TAG-Pd). Owing to the pincer-type architecture of the triazolium ligand, the stabilization of a high amount of palladium nanoparticles (16 wt %) has been possible. The catalytic system has been fully characterized and used in low amounts (i.e., 0.1 mol % palladium loading) in representative Heck-Mizoroki cross-coupling processes. A negligible release of the metal was demonstrated, and a high activity was obtained over more runs. Besides, the protocol has been optimized for the use of safe biomass-derived γ-valerolactone reaction medium  

    Synthesis, crystal structure and catalytic activity of a novel Mo(VI)-oxazoline complex in highly efficient oxidation of sulfides to sulfoxides by urea hydrogen peroxide

    , Article Inorganica Chimica Acta ; Volume 361, Issue 7 , 2008 , Pages 2019-2024 ; 00201693 (ISSN) Bagherzadeh, M ; Tahsini, L ; Latifi, R ; Ellern, A ; Woo, L. K ; Sharif University of Technology
    Elsevier S.A  2008
    Abstract
    Novel molybdenum complex, cis-[MoO2(phox)2] has been synthesized and characterized by IR, 1H NMR, elemental analyses (CHN), and X-ray molecular structure determination methods. This complex was found to be an efficient, selective catalyst for the oxidation of various sulfides to sulfoxides with urea hydrogen peroxide (UHP) in excellent yields (100% for diallylsulfide) and short reaction times (20 min) at room temperature. The catalytic system oxidizes diallylsulfide chemoselectively to its corresponding sulfoxide without any over oxidation in double bond. © 2007 Elsevier B.V. All rights reserved  

    Exploring source water mixing and transient residence time distributions of outflow and evapotranspiration with an integrated hydrologic model and Lagrangian particle tracking approach

    , Article Ecohydrology ; 2018 ; 19360584 (ISSN) Maxwell, R. M ; Condon, L. E ; Danesh Yazdi, M ; Bearup, L. A ; Sharif University of Technology
    John Wiley and Sons Ltd  2018
    Abstract
    Understanding the time water takes as it moves from rain or snowmelt through the terrestrial system to arrive as stream discharge, or evapotranspiration (ET) is an important hydrologic quantity. We develop a Lagrangian particle tracking method to capture transient residence times from source to either ET or outflow in an integrated hydrologic model. This method is parallel and efficiently captures time evolution of parcels of water in the model and tracks the source of water for hydrograph or ET separation. We demonstrate this model using hypothetical hillslope simulations driven by snow or rain dominated forcing and two different land cover types. We show that land cover and forcing both... 

    Optimized water consumption considering power plants efficiency in power system generation

    , Article 2019 IEEE International Conference on Industrial Technology, ICIT 2019, 13 February 2019 through 15 February 2019 ; Volume 2019-February , 2019 , Pages 673-678 ; 9781538663769 (ISBN) Ganjkhani, M ; Badakhshan, S ; Azizivahed, A ; Li, L ; Chen, L ; Huang, Q ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Abstract
    In order to generate adequate electricity energy, conventional power plants utilize dramatic volume of water resources. Different methods such as replacing cutting-edge technologies of facilities have been proposed to diminish water consumption in this industry. Most of the approaches are considered as medium or long-term solution which requires substantial investment costs. Meanwhile, because of the process and technology, natural gas-fired power plants need less water among conventional power plants. Therefore, shifting unit commitment planning toward these power plants would aid to save water consumption. Nevertheless, overlooking combined cycle power plants can perform negative impact on... 

    Synthesis, characterization and crystal structure of a dioxomolybdenum(VI) complex with a N,O type bidentate Schiff base ligand as a catalyst for homogeneous oxidation of olefins

    , Article Polyhedron ; Volume 28, Issue 12 , 2009 , Pages 2517-2521 ; 02775387 (ISSN) Bagherzadeh, M ; Latifi, R ; Tahsini, L ; Amani, V ; Ellern, A ; Keith Woo, L ; Sharif University of Technology
    2009
    Abstract
    The synthesis of a Mo(VI) Schiff base complex, cis-[MoO2{(4,6-bis(tert-butyl)-2-{(benzyl)iminomethyl}phenolate)2}], cis-[MoO2(L)2] where L = 4,6-bis(tert-butyl)-2-{(benzyl)iminomethyl}phenol, derived from benzylamine and 3,5-di-tert-butylsalycilaldehyde is reported. Full characterization of this complex was accomplished with elemental analyses, spectroscopic studies (NMR, IR and electronic) and X-ray structure analysis. This complex was tested as a catalyst for the homogeneous oxidation of olefins. The Mo(VI) complex is catalytically active for the epoxidation of aliphatic substrates at 80 °C, yielding the epoxide as the sole product in yields up to 100% and turnover numbers up to 5000....