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    Synthesis, characterization, electrochemical studies and catecholase-like activity of a series of mononuclear Cu(II), homodinuclear Cu(II)Cu(II) and heterodinuclear Cu(II)Ni(II) complexes of a phenol-based compartmental ligand

    , Article Journal of Molecular Catalysis A: Chemical ; Volume 241, Issue 1-2 , 2005 , Pages 1-7 ; 13811169 (ISSN) Boghaei, D. M ; Behzad, M ; Bezaatpour, A ; Sharif University of Technology
    A series of previously reported mononuclear Cu(II) and homodinuclear Cu(II)Cu(II) complexes, as well as, novel mononuclear Cu(II), homodinuclear Cu(II)Cu(II), and heterodinuclear Cu(II)Ni(II) complexes of a phenol-based dinucleating ligand with two different N(amine)2O2 and N(imine)2O2 coordination sites, were synthesized and characterized by elemental analyses, infrared and electronic absorption spectroscopies and conductivity measurements. The electrochemical behavior and catecholase-like activity of the complexes were also studied using cyclic voltammetry and UV-vis spectrophotometry, respectively. Our results show that the dinuclear complexes are more effective catalysts in the oxidation... 

    Design and fabrication of an in situ gamma radioactivity measurement system for marine environment and its calibration with Monte Carlo method

    , Article Applied Radiation and Isotopes ; Volume 114 , 2016 , Pages 87-91 ; 09698043 (ISSN) Abdollahnejad, H ; Vosoughi, N ; Zare, M. R ; Sharif University of Technology
    Elsevier Ltd  2016
    Simulation, design and fabrication of a sealing enclosure is carried out for a NaI(Tl) 2″×2″ detector, to be used as in situ gamma radioactivity measurement system in marine environment. Effect of sealing enclosure on performance of the system in laboratory and marine environment (distinct tank with 10 m3 volume) were studied using point sources. The marine volumetric efficiency for radiation with 1461 keV energy (from 40K) is measured with KCl volumetric liquid source diluted in distinct tank. The experimental and simulated efficiency values agreed well. Marine volumetric efficiency calibration curve is calculated for 60 keV to 1461 keV energy with Monte Carlo method. This curve indicates... 

    Label-free and simple detection of endotoxins using a sensitive LSPR biosensor based on silver nanocolumns

    , Article Analytical Biochemistry ; Volume 548 , 2018 , Pages 96-101 ; 00032697 (ISSN) Zandieh, M ; Hosseini, N ; Vossoughi, M ; Khatami, M ; Abbasian, S ; Moshaii, A ; Sharif University of Technology
    Academic Press Inc  2018
    This paper describes the construction of a silver-based LSPR biosensor for endotoxin detection. We used GLAD method to procure reproducible silver nanocolumns. In this work, the silver nanostructures were considerably stabilized by a SAM of MPA, and the limit of detection of biosensor was measured to be 340 pg/ml for endotoxin E. coli. Considering endotoxin B. abortus as the second type of endotoxin contamination in our target samples (HBs-ag produced in Institute Pasteur, Iran), we investigated selectivity of the biosensor in various experiments. We showed that this biosensor can selectively detect both types of endotoxins compared to other biological species. Overall, this study proposes... 

    SGSD: A novel Sequential Gamma-ray Spectrum Deconvolution algorithm

    , Article Annals of Nuclear Energy ; Volume 132 , 2019 , Pages 369-380 ; 03064549 (ISSN) Shahabinejad, H ; Vosoughi, N ; Sharif University of Technology
    Elsevier Ltd  2019
    A novel approach for analyzing complex gamma-ray spectra using a sequential algorithm is introduced. The developed Sequential Gamma-ray Spectrum Deconvolution (SGSD)algorithm produces a sequence of spectra converging to the best estimation of output spectrum of a gamma-ray detector. In each point of sequence, an isotope of unknown gamma-ray source is identified and the respective response of the detector to unknown source is reconstructed. Effectiveness of the developed algorithm is demonstrated by two empirical and simulation studies. In the case of empirical study, a number of recorded gamma-ray spectra related to a mixed gamma-ray source including different combinations of 5 isotopes... 

    A new method for determination of concentration profile in a transport column by gamma spectroscopy combined with genetic algorithm

    , Article Progress in Nuclear Energy ; Volume 124 , 2020 Dara, M ; Kazemi, Z ; Samadfam, M ; Sharif University of Technology
    Elsevier Ltd  2020
    A non-collimated gamma spectroscopy with fewer sampling (counting) and shorter sampling periods is developed and used to estimate the concentration profile of the radiotracers within the column. In this method, the radiotracer activity in the whole column is measured in a few different positions of the detector and then, by using an appropriate advection-dispersion model and the genetic algorithm, the concentration profile within the column is constructed. The concentration profile obtained by the new method fits very well to the experimentally obtained thin-section scanning results with RMSE less than 0.046. The uniqueness of the concentration profile obtained by the method was confirmed by... 

    RF reactive co-sputtered Au-Ag alloy nanoparticles in SiO 2 thin films

    , Article Applied Surface Science ; Volume 253, Issue 18 , 2007 , Pages 7438-7442 ; 01694332 (ISSN) Sangpour, P ; Akhavan, O ; Moshfegh, A. Z ; Sharif University of Technology
    Elsevier  2007
    We have studied formation of Au-Ag alloy nanoparticles in sputtered SiO 2 thin films. Silica thin films containing Au-Ag nanoparticles were deposited on quartz substrates using rf reactive magnetron co-sputtering technique. The films heat-treated in reducing Ar + H 2 atmosphere at different temperatures. They were analyzed by using UV-vis spectrophotometry, atomic force microscopy and X-ray photoelectron spectroscopy (XPS) methods for their optical, surface morphological as well as structural and chemical properties. The optical absorption of the Au-Ag alloy nanoparticles illustrated one plasmon resonance absorption peak located at 450 nm between the absorption bands of pure Au and Ag... 

    Investigation of EGRET gamma-ray sources by an extensive air shower experiment

    , Article 29th International Cosmic Ray Conference, ICRC 2005, Pune, 3 August 2005 through 10 August 2005 ; Volume 6 , 2005 , Pages 29-32 Khakian Ghomi, M ; Samimi, J ; Bahmanabadi, M ; Sharif University of Technology
    Tata Institute of Fundamental Research  2005
    Ultra-high-energy ( E ≥ TeV) Extensive Air Showers (EASs) have been monitored for a period of five years (1997-2003 ), using a small array of scintillator detectors in Tehran, Iran. The data have been analyzed to take in to account of the dependence of source counts on zenith angle. During a calendar year different sources come in the field of view of the detector at varying zenith angles. Because of varying thickness of the overlaying atmosphere, the shower count rate is extremely dependent on zenith angle which have been carefully analyzed over time. High energy gamma-ray sources from the EGRET third catalogue where observed and the data were analyzed using an excess method. Upper limits... 

    Preferential solvation and behavior of solvatochromic indicators in mixtures of an ionic liquid with some molecular solvents

    , Article The Journal of Physical Chemistry B ; vol.114 (29) , July , 2010 , pp 9586–9593 Salari, H. (Hadi) ; Khodadadi-Moghaddam, M.(Mohammad) ; Harifi-Mood, A. R. (Ali Reza) ; Gholami, M. R. (Mohammad Reza) ; Sharif University of Technology
    Structural and intermolecular interactions of solvatochromic probes 4-nitroaniline, 4-nitroanisole, and Reichardt’s dye were investigated in the binary mixtures of 2-hydroxy ethylammonium formate as an ionic liquid with N,N-dimethyl formamide, dimethyl amine, and dimethyl sulfoxide. Solvatochromic parameters (ETN, normalized polarity parameter; π*, dipolarity/polarizability; β, hydrogen-bond acceptor basicity; α, hydrogen -bond donor acidity) were determined in ionic liquid mixtures at 25 °C using UV−vis spectroscopy. ETN parameters obtained from absorbance of Reichardt’s dye within various mixtures of ionic liquid were observed to be higher than predicted values from ideal additive... 

    Colorimetric assay for exon 7 SMN1/SMN2 single nucleotide polymorphism using gold nanoprobes

    , Article BioImpacts ; Volume 3, Issue 4 , 2013 , Pages 185-194 ; 22285652 (ISSN) Ahmadpour Yazdi, H ; Hormozi Nezhad, M. R ; Abadi, A ; Sanati, M. H ; Kazemi, B ; Sharif University of Technology
    Introduction: Proximal spinal muscular atrophy (SMA) is one of the most significant neurodegenerative diseases amongst the autosomal-recessive genetic disorders which is caused by the absence of protein survival of motor neuron (SMN). A critical nucleotide difference in SMN2 compared to SMN1 gene leads to an inefficient protein. Hence, homozygous lack of SMN1 provides a progressive disease. Due to the high prevalence, up to now, several molecular diagnostic methods have been used which most of them are lengthy, expensive, and laborious. Methods: In the present study, we exploited a gold nanoprobe-based method for semi-quantitative SMN1 gene dosage analysis compared to SMN2. The assay was... 

    Sonochemical synthesis and measurement of optical properties of zinc sulfide quantum dots

    , Article Chemical Engineering Journal ; Volume 209 , 2012 , Pages 113-117 ; 13858947 (ISSN) Goharshadi, E. K ; Sajjadi, S. H ; Mehrkhah, R ; Nancarrow, P ; Sharif University of Technology
    A facile sonochemical method has been developed to prepare very small zinc sulfide nanoparticles (ZnS NPs) of extremely small size about 1. nm in diameter using a set of ionic liquids based on the bis (trifluoromethylsulfonyl) imide anion and different cations of 1-alkyl-3-methyl-imidazolium. The structural features and optical properties of the NPs were determined in depth with X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS) analysis, and UV-vis absorption spectroscopy. The energy band gap measurements of ZnS NPs were calculated by UV-vis absorption... 

    Photoactive and self-cleaning TiO 2-SiO 2 thin films on 316L stainless steel

    , Article Thin Solid Films ; Volume 520, Issue 20 , 2012 , Pages 6355-6360 ; 00406090 (ISSN) Boroujeny, B. S ; Afshar, A ; Dolati, A ; Sharif University of Technology
    In this study, TiO 2-SiO 2 nanocomposite films with different amounts of SiO 2 were prepared by sol-gel process and were coated onto stainless steel 316L. The effect of addition of various amount of SiO 2 in the precursor solution on the photocatalysis, photo-generated hydrophilicity and self-cleaning property of TiO 2 thin films was investigated by X-ray diffraction, Fourier transform infrared spectroscopy, water contact angle measurements and UV spectroscopy. In the tested ranges of SiO 2 content and sintering temperature, the highest photocatalytic activity and self-cleaning property were observed in the 15 mol% SiO 2 sample sintered at 750 °C. Addition of less than 30 mol% SiO 2 had a... 

    Catalyst-Free and Green Synthesis of Some Novel Benzamide Derivatives

    , Article Journal of Heterocyclic Chemistry ; Volume 52, Issue 6 , November , 2015 , Pages 1848-1857 ; 0022152X (ISSN) Samani Ghaleh Taki, B ; Rostami, M ; Mirkhani, V ; Moghadam, M ; Mohammadpoor Baltork, I ; Tangestaninejad, S ; Jamali Moghadam, A ; Kia, R ; Sharif University of Technology
    HeteroCorporation  2015
    In the present work, a simple, green, rapid, and catalyst-free procedure for the synthesis of benzamide derivatives by ring opening of azlactones with diamines such as ethylene diamine and 1,3-propylenediamine is described. The present method offers several advantages such as short reaction times, easy work-up, and mild reaction conditions in the absence of catalyst and any toxic solvent and material. In addition, the structure obtained by X-ray crystallography was compared with the theoretical results obtained by density functional theory using the B3LYP functional and cc-pVDZ basis sets  

    Preconcentration and determination of pantoprazole by solid-phase extraction coupled with spectrophotometry using iron oxide nanoparticles modified with cetyltrimethylammonium bromide

    , Article Nano Biomedicine and Engineering ; Volume 7, Issue 3 , 2015 , Pages 102-110 ; 21505578 (ISSN) Sayyahmanesh, M ; Naghian, E ; Sahebi, H ; Asgari, S ; Sharif University of Technology
    Open Access House of Science and Technology  2015
    Solid phase extraction coupled with spectrophotometric detection was applied to trace amounts of Pantoprazole (PP) drug using Cetyltrimethylammonium bromide coated-iron oxide magnetite nanoparticles CTAB@Fe3O4 MNPs. After characterization of the prepared nano-adsorbents, experimental parameters affecting the extraction efficiency of the developed method were optimized. The results obtained showed that this proposed approach is applicable in concentrations ranging from 0.1 to 1.5 μg/ml (R2 = 0.9958) indicating that follows Beer's-Lambert law. The limit of detection and the limit of quantification calculated to be 0.014 and 0.04 μg/ml, respectively. The repeatability of the proposed method was... 

    Preferential solvation and behavior of solvatochromic indicators in mixtures of an ionic liquid with some molecular solvents

    , Article Journal of Physical Chemistry B ; Volume 114, Issue 29 , 2010 , Pages 9586-9593 ; 15206106 (ISSN) Salari, H ; Khodadadi Moghaddam, M ; Harifi Mood, A. R ; Gholami, M. R ; Sharif University of Technology
    American Chemical Society  2010
    Structural and intermolecular interactions of solvatochromic probes 4-nitroaniline, 4-nitroanisole, and Reichardts dye were investigated in the binary mixtures of 2-hydroxy ethylammonium formate as an ionic liquid with N,N-dimethyl formamide, dimethyl amine, and dimethyl sulfoxide. Solvatochromic parameters (ETN, normalized polarity parameter; π, dipolarity/polarizability; β, hydrogen-bond acceptor basicity; α, hydrogen -bond donor acidity) were determined in ionic liquid mixtures at 25°C using UV-vis spectroscopy. ETN parameters obtained from absorbance of Reichardt dye within various mixtures of ionic liquid were observed to be higher than predicted values from ideal additive behavior.... 

    Synthesis of gold nanoparticle necklaces using linear-dendritic copolymers

    , Article European Polymer Journal ; Volume 46, Issue 2 , 2010 , Pages 165-170 ; 00143057 (ISSN) Tavakoli Naeini, A ; Adeli, M ; Vossoughi, M ; Sharif University of Technology
    Linear-dendritic copolymers containing hyperbranched poly(citric acid) and linear poly(ethylene glycol) blocks (PCA-PEG-PCA) were used as reducing and capping agents to synthesize and support gold nanoparticles (AuNPs). PCA-PEG-PCA copolymers with 1758, 1889 and 3446 molecular weights, called A1, A2 and A3 through this work, respectively, were synthesized using 2, 5, and 10 citric acid/PEG molar ratios. The diameter of A1, A2 and A3 in a fresh water solution was investigated using dynamic light scattering (DLS) and it was between 1.8 and 2.8 nm. AuNPs were simply synthesized and supported by addition a boiling aqueous solution of HAuCl4 to aqueous solutions of A1, A2 and A3. Supported AuNPs... 

    Analysis of complex gamma-ray spectra using particle swarm optimization

    , Article Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment ; Volume 911 , 2018 , Pages 123-130 ; 01689002 (ISSN) Shahabinejad, H ; Vosoughi, N ; Sharif University of Technology
    Elsevier B.V  2018
    Analysis of gamma-ray spectra is an important step for identification and quantification of radionuclides in a sample. In this paper a new gamma-ray spectra analysis algorithm based on Particle Swarm Optimization (PSO) is developed to identify different isotopes of a mixed gamma-ray source and determine their fractional abundances. PSO is an iterative algorithm that imitates the social behaviors observed in nature to solve complex optimization problems. The PSO method is used for complex fitting to the response of a 3 [Formula presented] 3 inch NaI (Tl) scintillation detector and the fitting process is controlled by a test for significance of abundance and computation of Theil coefficient.... 

    Effect of morphology on the solar photocatalytic behavior of ZnO nanostructures

    , Article Journal of Alloys and Compounds ; Volume 485, Issue 1-2 , 2009 , Pages 616-620 ; 09258388 (ISSN) Mohajerani, M ; Lak, A ; Simchi, A ; Sharif University of Technology
    ZnO nanostructures in the shape of particle, rods, flower-like and micro-sphere were synthesized via facile hydrothermal methods and the effect of morphology on the decolorization of CI Acid Red 27 solution under direct irradiation of sunlight was investigated. XRD patterns showed that the synthesized nanostructures have Wurtzite-type hexagonal structure with high crystallinity and crystallite size in the range of 67-100 nm. UV-vis absorption spectra indicated that the ZnO nanorods have higher visible light harvesting as compared to the other morphologies. The decolorization obeys the first order kinetics rate with the kinetics constant of 4.5-19.5 × 10-3 min-1 dependent on the ZnO... 

    Silver nanocube crystals on titanium nitride buffer layer

    , Article Journal of Physics D: Applied Physics ; Volume 42, Issue 10 , 2009 ; 00223727 (ISSN) Akhavan, O ; Sharif University of Technology
    Thermally stable cubic silver nanoparticles were grown by simply annealing a silver nano-thickness layer on a crystalline TiN buffer layer deposited on a Si(1 0 0) substrate. Formation of silver nanocubes was investigated by scanning electron microscopy, atomic force microscopy, x-ray diffractometry and UV-visible spectroscopy. The shapes of the silver nanoparticles were controlled by the thickness of the Ag layer. The silver nanocubes were self-ordered single crystals bounded mainly by {1 0 0} facets. It was found that a change in the shape of the nanoparticles from semi-spherical to cubic resulted in a substantial variation of their surface plasmon resonance absorption peak from 410 to 590... 

    Matrix effects corrections in prompt gamma-ray spectra of a PGNAA online analyzer system using artificial neural network

    , Article Progress in Nuclear Energy ; Volume 118 , 2020 Shahabinejad, H ; Vosoughi, N ; Saheli, F ; Sharif University of Technology
    Elsevier Ltd  2020
    One of the well-known online monitoring techniques used for quality control of bulk samples is Prompt Gamma Neutron Activation Analysis (PGNAA). PGNAA suffers from the so-called matrix effect problems such as density, thickness and moisture content of the sample under study. In this work, an Artificial Neural Network (ANN) model is introduced to deal with these effects. The required spectra for training and testing the proposed ANN model are obtained by Monte Carlo simulation of the gamma-ray spectra recorded in a PGNAA online analyzer system used in cement factories. The gamma-ray spectra related to given set of density, thickness and moisture content are corrected channel-to-channel using... 

    Comparison between two different hemichromes of hemoglobins (HbA and HbS) induced by n-dodecyl trimethylammonium bromide: Chemometric study

    , Article Colloids and Surfaces B: Biointerfaces ; Volume 63, Issue 2 , 2008 , Pages 183-191 ; 09277765 (ISSN) Mojtahedi, M ; Parastar, H ; Jalali Heravi, M ; Chamani, J ; Chilaka, F. C ; Moosavi Movahedi, A. A ; Sharif University of Technology
    The interaction of n-dodecyl trimethylammonium bromide (DTAB) with oxyhemoglobin A and oxyhemoglobin S is investigated using UV-visible absorption spectra and chemometric resolution techniques. Oxyhemoglobins (A and S) induced to partial oxidized form (ferrihemoglobin) by DTAB and finally transform to fully oxidized hemichrome. Hemichrome mole fractions of HbS are more than HbA because of more hydrophobic interaction of DTAB-HbS in second set of binding site relative to DTAB-HbA. The visible spectra between 500 and 650 nm are used for identifying the present components in solution because each species of hemoglobin has a specific spectrum in this region. The number of components and mole...