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    Blind identification of soil-structure systems

    , Article Soil Dynamics and Earthquake Engineering ; Volume 45 , February , 2013 , Pages 56-69 ; 02677261 (ISSN) Ghahari, S. F ; Ghannad, M. A ; Taciroglu, E ; Sharif University of Technology
    2013
    Abstract
    Surrounding soil can drastically influence the dynamic response of buildings during strong ground shaking. Soil's flexibility decreases the natural frequencies of the system; and in most cases, soil provides additional damping due to material hysteresis and radiation. The additional damping forces, which are in non-classical form, render the mode shapes of the soil-structure system complex-valued. The response of a soil-foundation system can be compactly represented through impedance functions that have real and imaginary parts representing the stiffness and damping of the system, respectively. These impedance functions are frequency-dependent, and their determination for different... 

    Position control of shape memory alloy actuator based on the generalized Prandtl-Ishlinskii inverse model

    , Article Mechatronics ; Volume 22, Issue 7 , 2012 , Pages 945-957 ; 09574158 (ISSN) Sayyaadi, H ; Zakerzadeh, M. R ; Sharif University of Technology
    2012
    Abstract
    Hysteresis and significant nonlinearities in the behavior of Shape Memory Alloy (SMA) actuators encumber effective utilization of these actuator. Due to these effects, the position control of SMA actuators has been a great challenge in recent years. Literature review of the research conducted in this area shows that using the inverse of the phenomenological hysteresis models can compensate the hysteresis of these actuators effectively. But, inverting some of these models, such as Preisach model, is numerically a complex task. However, the generalized Prandtl-Ishlinskii model is analytically invertible, and therefore can be implemented conveniently as a feedforward controller for compensating... 

    DFT and experimental study of the host-guest interactions effect on the structure, properties, and electro-catalytic activities of N 2O 2-Ni(II) schiff-base complexes incorporated into zeolite

    , Article Journal of Physical Chemistry C ; Volume 116, Issue 34 , 2012 , Pages 18518-18532 ; 19327447 (ISSN) Jafarian, M ; Rashvand Avei, M ; Khakali, M ; Gobal, F ; Rayati, S ; Mahjani, M. G ; Sharif University of Technology
    2012
    Abstract
    Ni II-(N,N′-bis(2,4-dihydroxyacetophenone)-2, 2-dimethylpropandiimine (Ni II{salnptn(4-OH) 2}) complex has been encapsulated within the supercage of zeolite-NaY by reacting Ni 2+-exchanged NaY with the flexible Schiff-base ligand that diffuses into the cavities. The encapsulated complex is characterized by EDX, scanning electron microscopy, powder X-ray diffraction, FT-IR, and cyclic voltammetry studies. Density functional calculation is being carried out on both the free nickel Schiff-base complex and that encapsulated in NaY zeolite to investigate changes in structural parameters, energies of the HOMO and LUMO, and absolute hardness and softness. Electrochemical properties of the NaY... 

    Performance of UWB linked relay network with time-reversed transmission in the presence of channel estimation error

    , Article IEEE Transactions on Wireless Communications ; Volume 11, Issue 8 , 2012 , Pages 2958-2969 ; 15361276 (ISSN) Zeinalpour Yazdi, Z ; Nasiri Kenari, M ; Aazhang, B ; Sharif University of Technology
    2012
    Abstract
    In this paper, we present the bit error probability (BEP) of a relay network employing UWB links between its nodes. Since UWB systems can resolve many paths and are thus rich in multipath diversity, the use of the Rake diversity combining is very effective. However, because of the complexity, it is impractical in the scenarios with portable terminals or in the networks with multiple relays. Time-reversal technique, in which the transmitting nodes can do the pre-diversity filtering of UWB signal before transmission, is known as an approach to achieve the performance equivalent to the Rake combining without increasing the receiver complexity. The performance of such a network with simple... 

    Electrochemical determinations of 6-mercaptopurine on the surface of a carbon nanotube-paste electrode modified with a cobalt salophen complex

    , Article Journal of Solid State Electrochemistry ; Volume 16, Issue 4 , April , 2012 , Pages 1643-1650 ; 14328488 (ISSN) Shahrokhian, S ; Ghorbani Bidkorbeh, F ; Mohammadi, A ; Dinarvand, R ; Sharif University of Technology
    2012
    Abstract
    A mixture of multi-walled carbon nanotube/graphite paste electrode modified with a salophen complex of cobalt was prepared and was applied for the study of the electrochemical behavior of 6-mercaptopurine (MP) using cyclic and differential pulse voltammetry (DPV). An excellent electrocatalytic activity toward the oxidation of MP was achieved, which led to a considerable lowering in the anodic overpotential and remarkable increase in the response sensitivity in comparison with unmodified electrode. Utilizing DPV method, a linear dynamic range of 1-100 μM with detection limit of 0.1 μM was obtained in phosphate buffer of pH 3.0. The electrochemical detection system was very stable, and the... 

    The use of a cis-dioxomolybdenum(VI) dinuclear complex with quadradentate 1,4-benzenediylbis(benzyldithiocarbamate)(2-) as model compound for the active site of oxo transfer molybdoenzymes: Reactivity, kinetics, and catalysis

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 88 , 2012 , Pages 210-215 ; 13861425 (ISSN) Moradi Shoeili, Z ; Boghaei, D. M ; Sharif University of Technology
    2012
    Abstract
    Dinuclear cis-dioxomolybdenum(VI) complex [{MoO 2(Bz 2Benzenediyldtc)} 2] coordinated by a quadradentate dithiocarbamate (Bz 2Benzenediyldtc 2- = 1,4-benzenediylbis(benzyldithiocarbamate)(2-)) has been prepared and characterized by elemental analysis, 13C NMR, IR and UV-vis spectroscopy. The kinetics of the oxygen atom transfer between [{MoO 2(Bz 2Benzenediyldtc)} 2] and PPh 3 was studied spectrophotometrically in CH 2Cl 2 medium at 520 nm and four different temperatures, 288, 293, 298 and 303 K, respectively. The reaction follows second order kinetics with the rate constant k = 0.163(2) M -1 S -1 and its increasingly strong absorption at 520 nm clearly indicate the formation of a μ-oxo... 

    Resolution and quantification of complex mixtures of polycyclic aromatic hydrocarbons in heavy fuel oil sample by means of GC × GC-TOFMS combined to multivariate curve resolution

    , Article Analytical Chemistry ; Volume 83, Issue 24 , 2011 , Pages 9289-9297 ; 00032700 (ISSN) Parastar, H ; Radović, J. R ; Jalali-Heravi, M ; Diez, S ; Bayona, J. M ; Tauler, R ; Sharif University of Technology
    Abstract
    Comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOFMS) combined to multivariate curve resolution-alternating least-squares (MCR-ALS) is proposed for the resolution and quantification of very complex mixtures of compounds such as polycyclic aromatic hydrocarbons (PAHs) in heavy fuel oil (HFO). Different GC × GC-TOFMS data slices acquired during the analysis of HFO samples and PAH standards were simultaneously analyzed using the MCR-ALS method to resolve the pure component elution profiles in the two chromatographic dimensions as well as their pure mass spectra. Outstandingly, retention time shifts within and between GC × GC runs were not affecting... 

    A GIS-google earth based approach to estimating the flood damage function in large river basins

    , Article World Environmental and Water Resources Congress 2011: Bearing Knowledge for Sustainability - Proceedings of the 2011 World Environmental and Water Resources Congress, 22 May 2011 through 26 May 2011 ; May , 2011 , Pages 3811-3821 ; 9780784411735 (ISBN) Abrishamchi, A ; Dashti, M ; Alamdari, N ; Salavitabar, A ; Sharif University of Technology
    2011
    Abstract
    Flood as a natural disaster causes heavy human and economic losses and social unrests in most areas of the world. As flood control cost and flood damage compensation is a heavy burden over countries' budget, traditional flood design methods are being replaced by more reliable risk-based methods employing comprehensive risk analysis. In this respect, flood damage estimation is an important step in flood control systems design and analysis. In large river basins with complex reservoir systems and various land uses, flood damage estimation is complex, data-intensive, time demanding, and uncertain task requiring an intensive hydrologic and hydraulic analysis. In this study a simple approach is... 

    Evolution of microstructures and mechanical properties in similar and dissimilar friction stir welding of AA5086 and AA6061

    , Article Materials Science and Engineering A ; Volume 528, Issue 28 , 2011 , Pages 8071-8083 ; 09215093 (ISSN) Jamshidi Aval, H ; Serajzadeh, S ; Kokabi, A. H ; Sharif University of Technology
    2011
    Abstract
    In this work, thermo-mechanical behavior and microstructural evolution in similar and dissimilar friction stir welding of AA6061-T6 and AA5086-O have been investigated. Firstly, the thermo-mechanical behaviors of materials during similar and dissimilar FSW operations have been predicted using three-dimensional finite element software, ABAQUS, then, the mechanical properties and the developed microstructures within the welded samples have been studied with the aid of experimental observations and model predictions. It is found that different strengthening mechanisms in AA5086 and AA6061 result in complex behaviors in hardness of the welded cross section where the hardness variation in similar... 

    Synthesis, X-ray structure, characterization and catalytic activity of a polymeric manganese(II) complex with iminodiacetate

    , Article Applied Organometallic Chemistry ; Volume 25, Issue 7 , 2011 , Pages 559-563 ; 02682605 (ISSN) Bagherzadeh, M ; Amini, M ; Boghaei, D. M ; Najafpour, M. M ; McKee, V ; Sharif University of Technology
    2011
    Abstract
    A polymeric manganese(II) complex with the general formula [Mn(O 2CCH2NH2CH2CO2) 2(H2O)2]n from reaction of iminodiacetatic acid and manganese(II) perchlorate under nitrogen in water, was synthesized and characterized. The structure of the complex was determined using single-crystal X-ray diffraction, elemental analysis, IR and UV-vis spectra. This complex exhibited excellent catalytic activity and selectivity for oxidation of various alcohols and sulfides to the corresponding aldehydes/ketone and sulfoxides using urea hydrogen peroxide and oxone (2KHSO 5·KHSO4·K2SO4), respectively, as oxidants under air at room temperature. The easy preparation, mild reaction conditions, high yields of the... 

    An enhanced neural network model for predictive control of granule quality characteristics

    , Article Scientia Iranica ; Volume 18, Issue 3 E , 2011 , Pages 722-730 ; 10263098 (ISSN) Neshat, N ; Mahloojifl, H ; Kazemi, A ; Sharif University of Technology
    2011
    Abstract
    An integrated approach is presented for predicting granule particle size using Partial Correlation (PC) analysis and Artificial Neural Networks (ANNs). In this approach, the proposed model is an abstract form from the ANN model, which intends to reduce model complexity via reducing the dimension of the input set and consequently improving the generalization capability of the model. This study involves comparing the capability of the proposed model in predicting granule particle size with those obtained from ANN and Multi Linear Regression models, with respect to some indicators. The numerical results confirm the superiority of the proposed model over the others in the prediction of granule... 

    Fully implicit compositional thermal simulator using rigorous multiphase calculations

    , Article Scientia Iranica ; Volume 18, Issue 3 C , June , 2011 , Pages 509-517 ; 10263098 (ISSN) Khorsandi Kouhanestani, S ; Bozorgmehry Boozarjomehry, R ; Pishvaie, M. R ; Sharif University of Technology
    2011
    Abstract
    Simulation of the in-situ combustion process is one of the most complex simulations amongst other reservoir flow simulations. Accurate simulation of the process is critical to obtain a successful implementation of the in-situ combustion process. Several factors impact performance of the simulation of this process. First are all the numerical models used for different sub-processes, such as reactions, fluid phase behavior, heat loss to surrounding formations and fluid physical properties. In the previous numerical models of the in-situ combustion process, very simplified models were used for the phase behavior of the fluid. Recent studies show that the fluid phase behavior model has a great... 

    Design and Synthesis of Novel Polyglycerol Hybrid Nanomaterials for Potential Applications in Drug Delivery Systems

    , Article Macromolecular Bioscience ; Volume 11, Issue 3 , NOV , 2011 , Pages 383-390 ; 16165187 (ISSN) Zarrabi, A ; Adeli, M ; Vossoughi, M ; Shokrgozar, M. A ; Sharif University of Technology
    2011
    Abstract
    The synthesis of a new drug delivery system based on hybrid nanomaterials containing a β-CD core and hyperbranched PG is described. Conjugating PG branches onto β-CD not only increases its water solubility but also affects its host/guest properties deeply. It can form molecular inclusion complexes with small hydrophobic guest molecules such as ferrocene or FITC with reasonable release. In addition, the achievable payloads are significantly higher as for carriers such as hyperbranched PGs. Short-term in vitro cytotoxicity and hemocompatibility tests on L929 cell lines show that the hybrid nanomaterial is highly biocompatible. Due to their outstanding properties, β-CD-g-PG hybrid nanomaterials... 

    The structure, magnetism and EPR spectra of a (μ-thiophenolato)(μ-pyrazolato-N,N′) double bridged dicopper(II) complex

    , Article Dalton Transactions ; Volume 44, Issue 5 , Dec , 2015 , Pages 2431-2438 ; 14779226 (ISSN) Khadir, N ; Boghaei, D. M ; Assoud, A ; Nascimento, O. R ; Nicotina, A ; Ghivelder, L ; Calvo, R ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Abstract
    A new binuclear copper(ii) complex, namely [Cu2L(pz)(DMSO)], where L = 2,6-bis[(2-phenoxy)iminomethyl]-4-methylthiophenolate(3-) and pz = pyrazolate ligand, has been synthesized by a one-pot synthesis involving copper(ii) acetate monohydrate, the S-protected ligand precursor 2-(N,N-dimethylthiocarbamato)-5-methylisophthalaldehyde di-2′-hydroxy anil, (I), and pyrazole, in which a metal-promoted S-deprotection reaction occurs during the formation of the complex. This was characterized by routine physicochemical studies, single crystal X-ray diffraction and electron paramagnetic resonance (EPR) techniques. The structure analysis reveals that there are copper centres in two different... 

    Photocatalytic activity of mesoporous microbricks of ZnO nanoparticles prepared by the thermal decomposition of bis(2-aminonicotinato) zinc (II)

    , Article Cuihua Xuebao/Chinese Journal of Catalysis ; Volume 36, Issue 5 , May , 2015 , Pages 742-749 ; 02539837 (ISSN) Bijanzad, K ; Tadjarodi, A ; Akhavan, O ; Sharif University of Technology
    Science Press  2015
    Abstract
    Hollow microblocks of [Zn(anic)2], as a novel coordination compound, were synthesized using 2-aminonicotinic acid (Hanic) and zinc (II) nitrate tetrahydrate. The chemical composition of the zinc complex, ZnC12H10N4O4, was determined by Fourier transform infrared (FTIR) spectroscopy and elemental analysis. The synthesized zinc complex was used as a precursor to produce ZnO nanostructures by calcination at 550 °C for 4 h. Morphological studies by scanning electron microscopy and transmission electron microscopy revealed the formation of porous microbricks of ZnO nanoparticles. N2 adsorption-desorption analysis showed that the... 

    Bio alcohol production from agricultural residues

    , Article 3rd International Symposium on Biotechniques for Air Pollution Control, Delft, 28 September 2009 through 30 September 2009 ; 2010 , Pages 167-174 ; 9780415582704 (ISBN) Alemzadeh, I ; Vossoughi, M ; Sharif University of Technology
    Abstract
    The bioconversion of abundant and renewable cellulosic biomass into ethanol as an alternative to petroleum is gaining importance due to the realization of diminishing natural oil and gas resources. Agricultural and foresty plant residues are an abundant and renewable source of sugar substrates that could be fermented to ethanol. A thermochemical treatment of biomass in which both cellulose and hemicellulose are hydrolyzed to soluble sugar is necessary before yeast fermentation. After thermochemical treatment, cellulase enzymes must be introduced in the system to hydrolyze any remaining cellulose. The simultaneous saccharification and fermentation (SSF), is a method which converts... 

    Fuel management optimization based on power profile by Cellular Automata

    , Article Annals of Nuclear Energy ; Volume 37, Issue 12 , 2010 , Pages 1712-1722 ; 03064549 (ISSN) Fadaei, A. H ; Moghaddam, N. M ; Zahedinejad, E ; Fadaei, M. M ; Kia, S ; Sharif University of Technology
    Abstract
    Fuel management in PWR nuclear reactors is comprised of a collection of principles and practices required for the planning, scheduling, refueling, and safe operation of nuclear power plants to minimize the total plant and system energy costs to the extent possible. Despite remarkable advancements in optimization procedures, inherent complexities in nuclear reactor structure and strong inter-dependency among the fundamental parameters of the core make it necessary to evaluate the most efficient arrangement of the core. Several patterns have been presented so far to determine the best configuration of fuels in the reactor core by emphasis on minimizing the local power peaking factor (Pq). In... 

    Characterization of LiCoO2 nanopowders produced by sol-gel processing

    , Article Journal of Nanomaterials ; Volume 2010 , 2010 ; 16874110 (ISSN) Asgari, S ; Soltanmohammad, S ; Sharif University of Technology
    2010
    Abstract
    LiCoO2 nanopowders, one of the most important cathode materials for lithium-ion batteries, were synthesized via a modified sol-gel process assisted with triethanolamine (TEA) as a complexing agent. The influence of three different chelating agents including acrylic acid, citric acid, and oxalic acid on the size and morphology of particles was investigated. Structure and morphology of the synthesized powders were characterized by thermogravimetric/ differential thermal analyses (TG/DTA), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Results indicate that the powder processed with TEA and calcinated at 800 °C had an excellent hexagonal ordering of α-NaFeO2 -type (space... 

    Piezoelectric composites with periodic multi-coated inhomogeneities

    , Article International Journal of Solids and Structures ; Volume 47, Issue 21 , October , 2010 , Pages 2893-2904 ; 00207683 (ISSN) Hashemi, R ; Weng, G. J ; Kargarnovin, M. H ; Shodja, H. M ; Sharif University of Technology
    Abstract
    A new, robust homogenization scheme for determination of the effective properties of a periodic piezoelectric composite with general multi-coated inhomogeneities is developed. In this scheme the coating does not have to be thin, the shape and orientation of the inclusion and coatings do not have to be identical, their centers do not have to coincide, their properties do not have to remain uniform, and the microstructure can be with the 2D elliptic or the 3D ellipsoidal inclusions. The development starts from the local electromechanical equivalent inclusion principle through the introduction of the position-dependent equivalent eigenstrain and electric field. Then with a Fourier series... 

    Electrochemical investigation of electrodeposited Fe-Pd alloy thin films

    , Article Electrochimica Acta ; Volume 56, Issue 1 , 2010 , Pages 483-490 ; 00134686 (ISSN) Rezaei, M ; Ghorbani, M ; Dolati, A ; Sharif University of Technology
    Abstract
    In the present study, the electrodeposition of Fe, Pd and Fe-Pd alloys, in alkaline solutions, has been investigated. Using ammonium hydroxide and trisodium citrate as the complexing agents, it has been shown that the co-deposition of Fe and Pd is achieved due to diminishing the difference between the reduction potentials of these two metals. Cyclic voltammetry results clearly show that the electrodeposition processes are diffusion-controlled and the diffusion coefficients of Fe2+ and Pd2+ are 1.11 × 10-6 and 2.19 × 10-5 cm2 s -1, respectively. The step potential experiments reveal that nucleation mechanism is instantaneous with a typical three-dimensional (3D) growth. At low overpotentials,...